U.S. patent application number 11/785242 was filed with the patent office on 2007-12-20 for geothermal air conditioning system.
Invention is credited to In Kyu Kim, Jung Hoon Kim, Jae Yoon Koh.
Application Number | 20070289319 11/785242 |
Document ID | / |
Family ID | 38832221 |
Filed Date | 2007-12-20 |
United States Patent
Application |
20070289319 |
Kind Code |
A1 |
Kim; In Kyu ; et
al. |
December 20, 2007 |
Geothermal air conditioning system
Abstract
Provided is a geothermal air conditioning system. The system
includes a plurality of indoor units, at least one outdoor unit, a
ground heat exchanger, and an auxiliary heat source. The plurality
of indoor units condition indoor air, the at least one outdoor unit
communicates with the indoor units via, a plurality of pipes, and
includes an outdoor heat exchanger where heat exchange occurs, and
a plurality of compressors for compressing coolant. The ground heat
exchanger is connected with the outdoor heat exchanger of the
outdoor unit, and laid under the ground to allow heat to be
exchanged between ground heat and a circulating medium circulating
through the ground heat exchanger. The auxiliary heat source is
installed on one side of the outdoor unit to assist heat exchange
of the outdoor heat exchanger.
Inventors: |
Kim; In Kyu; (Jinhae-si,
KR) ; Kim; Jung Hoon; (Changwon-si, KR) ; Koh;
Jae Yoon; (Seoul, KR) |
Correspondence
Address: |
Song K. Jung;MCKENNA LONG & ALDRIDGE LLP
1900 K Street, N.W.
Washington
DC
20006
US
|
Family ID: |
38832221 |
Appl. No.: |
11/785242 |
Filed: |
April 16, 2007 |
Current U.S.
Class: |
62/175 |
Current CPC
Class: |
F24T 2010/56 20180501;
F24F 5/0046 20130101; F24F 2005/0057 20130101; Y02E 10/10 20130101;
Y02B 10/40 20130101; F24T 50/00 20180501 |
Class at
Publication: |
62/175 |
International
Class: |
F24F 5/00 20060101
F24F005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 16, 2006 |
KR |
10-2006-0054274 |
Claims
1. A geothermal air conditioning system comprising: a plurality of
indoor units for conditioning indoor air; at least one outdoor unit
communicating with the indoor units via a plurality of pipes, and
including an outdoor heat exchanger where heat exchange occurs, and
a plurality of compressors for compressing coolant; a ground heat
exchanger connected with the outdoor heat exchanger of the outdoor
unit, and laid under the ground to allow heat to be exchanged
between ground heat and a circulating medium circulating through
the ground heat exchanger; and an auxiliary heat source installed
on one side of the outdoor unit to assist heat exchange of the
outdoor heat exchanger.
2. The system according to claim 1, wherein the compressor
comprises: a constant-speed compressor operating in a constant
speed; and an inverter compressor, which is a variable speed heat
pump.
3. The system according to claim 2, wherein the constant-speed
compressor is selectively used depending on the number of indoor
units of the plurality of indoor units, that are required to
operate for one of a cooling cycle and a heating cycle.
4. The system according to claim 2, wherein the constant-speed
compressor is additionally operated when a load increases and is
not handled by the inverter compressor alone.
5. A geothermal air conditioning system comprising: a plurality of
indoor units for conditioning indoor air; a plurality of outdoor
units provided on one side of the indoor unit and including an
outdoor heat exchanger where coolant circulating through the
outdoor heat exchanger exchanges heat with outside air, and a
compressor for compressing the coolant; a plurality of ground heat
exchangers connected with the outdoor heat exchanger of the outdoor
unit, and laid under the ground to allow heat to be exchanged
between ground heat and a circulating medium circulating through
the ground heat exchangers; and a circulation distributor installed
between the plurality of outdoor heat exchangers and the ground
heat exchangers to control flow of the circulating medium depending
on an operating condition.
6. The system according to claim 5, wherein a circulating pipe is
provided between the outdoor heat exchanger and the ground heat
exchanger to guide circulation of the circulating medium, and a
circulating pump for forcing flowing of the circulating medium is
installed at the circulating pipe.
7. The system according to claim 6, wherein the circulation
distributor controls the circulating medium supplied to the
plurality of ground heat exchangers depending on one of a user's
setting and a load condition.
8. The system according to claim 6, wherein the circulation
distributor controls the circulating medium to selectively flow to
the outdoor heat exchangers depending on whether the plurality of
outdoor heat exchangers operate.
9. The system according to claim 6, wherein a plurality of
circulating pumps are installed.
10. The system according to claim 9, wherein the circulating pump
comprises: a fixed delivery type circulating pump having a fixed
volume to be delivered; and a variable delivery type circulating
pump whose volume to be delivered is variable.
11. The system according to claim 10, wherein the fixed delivery
type circulating pump is additionally operated when loads applied
to the plurality of outdoor heat exchangers increase and are not
handled by the variable delivery type circulating pump alone.
12. The system according to claim 5, further comprising a coolant
distributor connected between the plurality of indoor units and
outdoor units to control the coolant's flow depending on an
operating condition.
13. A geothermal air conditioning system comprising: a plurality of
indoor units for conditioning indoor air; at least one outdoor unit
communicating with the indoor units via a plurality of pipes, and
including an outdoor heat exchanger where heat exchange occurs, and
a plurality of compressors for compressing coolant; a ground heat
exchanger connected with the outdoor heat exchanger of the outdoor
unit, and laid under the ground to allow heat to be exchanged
between ground heat and a circulating medium circulating through
the ground heat exchanger; an auxiliary heat source installed on
one side of the outdoor unit to assist heat exchange of the outdoor
heat exchanger; a circulation distributor installed between the
plurality of outdoor heat exchangers and the ground heat exchangers
to control flow of the circulating medium depending on an operating
condition; a circulating pipe installed between the outdoor heat
exchanger and the ground heat exchanger to guide circulation of the
circulating medium; and circulating pumps installed at the
circulating pipe to force flowing of the circulating medium.
14. The system according to claim 13, wherein the circulating pump
comprises: a fixed delivery type circulating pump having a fixed
volume to be delivered; and a variable delivery type circulating
pump whose volume to be delivered is variable.
15. The system according to claim 14, wherein the fixed delivery
type circulating pump is additionally operated when loads applied
to the plurality of outdoor heat exchangers increase and are not
handled by the variable delivery type circulating pump alone.
16. The system according to claim 13, wherein the compressor
comprises: a constant-speed compressor operating in a constant
speed; and an inverter compressor, which is a variable speed heat
pump.
17. The system according to claim 16, wherein the constant-speed
compressor is selectively used depending on the number of indoor
units of the plurality of indoor units, that are required to
operate for one of a cooling cycle and a heating cycle.
18. The system according to claim 16, wherein the constant-speed
compressor is additionally operated when a load increases and is
not handled by the inverter compressor alone.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a geothermal air
conditioning system, and more particularly, to an air conditioning
system including a plurality of ground heat exchangers having a
plurality of circulating pumps that can operate individually and
selectively to perform heat exchange using ground heat, and
including a plurality of compressors provided to an outdoor unit
and selectively used depending on a load.
[0003] 2. Description of the Related Art
[0004] Generally, an air conditioning system called an air
conditioner a cooling/heating system for cooling an indoor space
through repetition of sucking warm indoor air, exchanging heat with
coolant of low temperature, and discharging the indoor space, or
for heating the indoor space through a reverse operation. The air
conditioning system provides a series of cycles of a
compressor-condenser-expansion valve-evaporator.
[0005] Also, recently, the air conditioning system also provides an
air conditioning function of sucking and filtering polluted air of
the indoor space, purifying the polluted air into clean air, and
supplying the clean air back to the indoor space, and a variety of
additional functions such as a dehumidifying function of changing
humid air into dry air and supplying the dry air back to the indoor
space.
[0006] Meanwhile, as is generally known in the art, an air
conditioner is roughly classified into a separation type air
conditioner where an outdoor unit and an indoor unit are separately
installed, and an integral type air conditioner where the outdoor
unit and the indoor unit are integrally installed.
[0007] However, a related art air conditioner maintains an indoor
space at an appropriate state through a heat exchange operation
between coolant of the inside of the air conditioner and outside
air. Therefore, temperature of outside air is too low during a
heating cycle, and too high during a cooling cycle in a heat
exchange system using the air.
[0008] Therefore, great energy is consumed in absorbing and
exhausting heat from coolant. When temperature of outside air is
not constant, it is difficult to stably operate a cooling cycle and
a heating cycle due to abnormality of a heat source required for
the heating/cooling cycles.
[0009] Meanwhile, to solve problems of a heat exchange system using
outside air, there recently emerges a basic air conditioning system
performing outside heat exchange using ground heat as a heat
source. Therefore, since the air conditioning system using the
ground heat exchanges heat using ground heat as a heat source
without an influence caused by temperature of outside air, it
provides higher thermal efficiency (coefficient-of-performance
(COP) and energy efficiency ratio (EER)) than that of an air
conditioning system using air.
[0010] However, an air conditioning system using ground heat has
lots of problems. That is, despite advantages such as thermal
efficiency improvement, the air conditioning system using ground
heat still has a problem that stability and reliability of
cooling/heating cycles decreases when coolant that has flowed
through an outdoor heat exchanger after it exchanges heat in an
indoor space does not sufficiently exhaust/absorb heat to/from the
ground during cooling/heating cycles.
[0011] Also, since a related art air conditioning system uses only
one compressor or pump for flowing of fluid such as coolant, the
compressor or pump cannot be selectively used depending on capacity
of a load. Therefore, a high capacity compressor or pump with
consideration of a maximum load should be always used. Accordingly,
power is wasted in the case where a relatively low load is
required.
SUMMARY OF THE INVENTION
[0012] Accordingly, the present invention is directed to a
geothermal air conditioning system that substantially obviates one
or more problems due to limitations and disadvantages of the
related art.
[0013] An object of the present invention is to provide a
geothermal air conditioning system for exchanging heat using ground
heat.
[0014] Another object of the present invention is to provide a
geothermal air conditioning system including a plurality of outdoor
heat exchangers and ground heat exchangers, wherein circulation
distributors are provided between the outdoor heat exchangers and
the ground heat exchangers to control flow of circulating
media.
[0015] A further another object of the present invention is to
provide a geothermal air conditioning system including a plurality
of circulating pumps that can be selectively used depending on a
load condition.
[0016] A still further another object of the present invention to
provide a geothermal air conditioning system including an auxiliary
heat source for allowing heat to be sufficiently exchanged at an
outdoor heat exchanger.
[0017] An even further another object of the present invention is
to provide a geothermal air conditioning system including a
plurality of compressors, wherein an extra compressor is
selectively used depending on load capacity.
[0018] Additional advantages, objects, and features of the
invention will be set forth in part in the description which
follows and in part will become apparent to those having ordinary
skill in the art upon examination of the following or may be
learned from practice of the invention. The objectives and other
advantages of the invention may be realized and attained by the
structure particularly pointed out in the written description and
claims hereof as well as the appended drawings.
[0019] To achieve these objects and other advantages and in
accordance with the purpose of the invention, as embodied and
broadly described herein, there is provided a geothermal air
conditioning system including: a plurality of indoor units for
conditioning indoor air; at least one outdoor unit communicating
with the indoor units via a plurality of pipes, and including an
outdoor heat exchanger where heat exchange occurs, and a plurality
of compressors for compressing coolant; a ground heat exchanger
connected with the outdoor heat exchanger of the outdoor unit, and
laid under the ground to allow heat to be exchanged between ground
heat and a circulating medium circulating through the ground heat
exchanger; and an auxiliary heat source installed on one side of
the outdoor unit to assist heat exchange of the outdoor heat
exchanger.
[0020] In another aspect of the present invention, there is
provided a geothermal air conditioning system including: a
plurality of indoor units for conditioning indoor air; a plurality
of outdoor units provided on one side of the indoor unit and
including an outdoor heat exchanger where coolant circulating
through the outdoor heat exchanger exchanges heat with outside air,
and a compressor for compressing the coolant; a plurality of ground
heat exchangers connected with the outdoor heat exchanger of the
outdoor unit, and laid under the ground to allow heat to be
exchanged between ground heat and a circulating medium circulating
through the ground heat exchangers; and a circulation distributor
installed between the plurality of outdoor heat exchangers and the
ground heat exchangers to control flow of the circulating medium
depending on an operating condition.
[0021] In further another aspect of the present invention, there is
provided a geothermal air conditioning system including: a
plurality of indoor units for conditioning indoor air; at least one
outdoor unit communicating with the indoor units via a plurality of
pipes, and including an outdoor heat exchanger where heat exchange
occurs, and a plurality of compressors for compressing coolant; a
ground heat exchanger connected with the outdoor heat exchanger of
the outdoor unit, and laid under the ground to allow heat to be
exchanged between ground heat and a circulating medium circulating
through the ground heat exchanger; an auxiliary heat source
installed on one side of the outdoor unit to assist heat exchange
of the outdoor heat exchanger; a circulation distributor installed
between the plurality of outdoor heat exchangers and the ground
heat exchangers to control flow of the circulating medium depending
on an operating condition; a circulating pipe installed between the
outdoor heat exchanger and the ground heat exchanger to guide
circulation of the circulating medium; and circulating pumps
installed at the circulating pipe to force flowing of the
circulating medium.
[0022] A geothermal air conditioning system of the present
invention is used for improving an air conditioning
performance.
[0023] First, coolant at an outdoor heat exchanger provided to an
outdoor unit exchanges heat using circulating medium such as water.
The circulating medium exchanges heat with ground heat at a ground
heat exchanger laid deep under the ground. Since the outdoor heat
exchanger is a water-cooled heat exchanger where heat is exchanged
between a circulating medium (water) and ground heat as described
above, the outdoor heat exchanger of the present invention provides
relatively higher thermal efficiency of COP and EER than that of a
related art heat exchanger using air. Therefore, an air
conditioning performance of the air conditioning system
improves.
[0024] Second, the present invention provides a system for cooling
or heating a circulating medium using an auxiliary heat source
besides a ground heat exchanger that uses ground heat. Therefore,
in the case where ground heat is insufficient in condensing or
evaporating coolant at an outdoor heat exchanger, the auxiliary
heat source operates to assist heating or cooling of a circulating
medium. Therefore, there is an advantage that coolant can be
evaporated or condensed using the auxiliary heat source even under
an environment where ground heat is insufficient for the outdoor
heat exchanger to evaporate or condense the coolant. That is, an
air conditioning system according to the present invention exhibits
a stable air conditioning performance, not affected by ground
heat.
[0025] Third, a constant-speed compressor and an inverter
compressor are provided according to the present invention, and
selectively used depending on a size of a load. Therefore, since
only the inverter compressor operates when a relatively low load is
required, power is saved compared to the case where a high-capacity
single compressor is used in a related art. That is, it is possible
to prevent wasting power for driving a compressor in the case where
a low load is required.
[0026] Fourth, a plurality of outdoor units, indoor units, and
ground heat exchangers are provided, and a coolant distributor for
distributing coolant and a circulation distributor for distributing
a circulating medium are installed according to the present
invention. Therefore, since only some of the indoor units, the
outdoor units, and the ground heat exchangers can be used depending
on a selection of a user or a set value of a control unit, energy
is saved. That is, since an operation of unnecessary units is
prevented, an energy efficiency improves.
[0027] Fifth, a plurality of circulating pumps for supplying a
circulating medium are provided according to the present invention.
Therefore, since some of the circulating pumps can be selectively
used depending on a load, costs are saved in comparison with the
case where a maximum capacity pump is installed uniformly and
operated as in the related art.
[0028] It is to be understood that both the foregoing general
description and the following detailed description of the present
invention are exemplary and explanatory and are intended to provide
further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The accompanying drawings, which are included to provide a
further understanding of the invention and are incorporated in and
constitute a part of this application, illustrate embodiment(s) of
the invention and together with the description serve to explain
the principle of the invention. In the drawings:
[0030] FIG. 1 is a view illustrating a geothermal air conditioning
system is installed according to a first embodiment of the present
invention;
[0031] FIG. 2 is a block diagram illustrating a construction and a
coolant flow of a geothermal air conditioning system according to
the present invention;
[0032] FIG. 3 is a view illustrating a geothermal air conditioning
system is installed according to a second embodiment of the present
invention;
[0033] FIG. 4 is a block diagram illustrating a construction and a
coolant flow of a geothermal air conditioning system according to a
second embodiment of the present invention;
[0034] FIG. 5 is a view illustrating a construction of an outdoor
unit, which is a crucial part of a geothermal air conditioning
system according to the present invention;
[0035] FIG. 6 is a block diagram illustrating connections of an
auxiliary heat source constituting a geothermal air conditioning
system according to the present invention;
[0036] FIG. 7 is a block diagram illustrating a hot water heat pump
according to an embodiment of the present invention;
[0037] FIG. 8 is a view illustrating flow of coolant and a
circulating medium according to a first embodiment of the present
invention;
[0038] FIG. 9 is a view illustrating a circulating medium
circulates through a circulating pipe in a geothermal air
conditioning system according to the present invention;
[0039] FIG. 10 is a view illustrating flow of a circulating medium
when a hot water heat pump in a geothermal air conditioning system
according to the present invention;
[0040] FIG. 11 is a view illustrating flow of a circulating medium
when a boiler operates according to an embodiment of the present
invention;
[0041] FIG. 12 is a view illustrating flow of a circulating medium
when a cooling tower operates according to an embodiment of the
present invention;
[0042] FIG. 13 is a view illustrating flow of coolant and a
circulating medium when partial cooling and partial heating are
performed according to a second embodiment of the present
invention; and
[0043] FIGS. 14 and 15 are partial enlarged views illustrating flow
of a circulating medium according to a second embodiment of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0044] Reference will now be made in detail to the preferred
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings. The present invention
provides a geothermal air conditioning system that uses an outdoor
unit also called ground source heat pumps (GSHPs). The geothermal
air conditioning system is a system that uses ground heat as a heat
source of an outdoor heat exchanger, wherein the outdoor heat
exchanger exchanges heat using water (heat exchange water) having a
predetermined temperature caused by the ground heat.
[0045] FIG. 1 is a view illustrating a geothermal air conditioning
system is installed according to a first embodiment of the present
invention, and FIG. 2 is a block diagram of a geothermal air
conditioning system according to the present invention.
[0046] Referring to FIGS. 1 and 2, the geothermal air conditioning
system includes one or more indoor units 200 for conditioning
indoor air, one or more outdoor units 100 for communicating with
the indoor units 100 via a plurality of pipes, a ground heat
exchanger 300 laid under the ground to allow heat to be exchanged
between ground heat and a circulating medium circulating through an
inside of the ground heat exchanger; and a plurality of auxiliary
heat sources 400, 450, and 460 for assisting heat exchange at an
outdoor heat exchanger provided to the outdoor unit 100.
[0047] The outdoor unit 100 includes a constant-speed compressor
120, an inverter compressor 120', an accumulator 132, an outdoor
heat exchanger 140, and an outdoor linear expansion valve (LEV)
102. The indoor unit 200 includes an indoor heat exchanger 202 and
an expansion valve 204.
[0048] In an air conditioner, a plurality of indoor units 200 are
connected to one or more outdoor units 100. A single common liquid
pipe 210 through which liquid coolant flows and a single common gas
pipe 212 through which gas coolant flows are installed between the
outdoor units 100 and the indoor units 200 so that they communicate
with each other. Also, a high-low pressure common pipe 214 for
maintaining balance of coolant is installed between two or more
outdoor units 100 so that the outdoor units 100 communicate with
each other.
[0049] The high-low pressure common pipe 214 is installed such that
entries of outdoor heat exchangers 140 provided to the plurality of
outdoor units 100 communicate with each other to maintain balance
of coolant among the outdoor units 100. Meanwhile, the high-low
pressure common pipe 214 allows coolant to flow into even an
outdoor heat exchanger 140 of the outdoor unit 100 that is not
used. Accordingly, a heat exchange efficiency improves on the
whole. Also, high pressure coolant or low pressure coolant flows
through a low the high-low pressure common pipe 214 depending on a
cooling cycle and a heating cycle.
[0050] Branch liquid pipes 210' through which liquid coolant flows,
and branch gas pipes 212' through which gas coolant flows are
provided to the indoor units 200. The branch liquid pipes 2101 and
the branch gas pipes 212' communicate with the common liquid pipe
210 and the common gas pipe 212, respectively.
[0051] Also, the branch liquid pipes 210' and the branch gas pipes
212' have a different diameter depending on a capacity of the
indoor unit 200 connected thereto.
[0052] Meanwhile, outdoor liquid pipes 210'' through which liquid
coolant flows, and outdoor gas pipes 212'' through which gas
coolant flows are provided to the outdoor units 100. The outdoor
liquid pipes 210'' and the outdoor gas pipes 212'' communicate with
the common liquid pipe 210 and the common gas pipe 212,
respectively.
[0053] The plurality of auxiliary heat sources 400, 450, and 460
heat or cool a circulating medium flowing through the ground heat
exchanger 300. Two or more of the auxiliary heat sources 400, 450,
and 460 are simultaneously operated, or one of them is selectively
used.
[0054] Referring to FIG. 2, the plurality of auxiliary heat sources
400, 450, and 460 include a hot water heat pump 400, a boiler 450,
and a cooling tower 460. Of course, one of the hot water heat pump
400, the boiler 450, and the cooling tower 460 can be provided as
the auxiliary heat sources 400, 450, and 460. Also, another
apparatus can be further provided.
[0055] The hot water heat pump 400 is installed between the outdoor
unit 100 and the ground heat exchanger 300 to allow the circulating
medium circulating through the ground heat exchanger 300 to emit
hot air through heat exchange with other exchange water.
[0056] The boiler 450 is installed between the outdoor unit 100 and
the ground heat exchanger 300 to heat the circulating medium
circulating through the ground heat exchanger 300.
[0057] The cooling tower 460 is installed between the outdoor unit
100 and the ground heat exchanger 300 to cool down the circulating
medium circulating through the ground heat exchanger 300. A cooling
pump 468 for forcing flowing of the circulating medium (water) that
has passed through the cooling tower 460 is further installed
inside or outside the cooling tower 460.
[0058] A circulating pipe 310 is provided between the outdoor heat
exchanger 140 of the outdoor unit 100 and the ground heat exchanger
300 to guide circulation of the circulating medium. The circulating
medium is formed of a material, preferably, water (H.sub.2O) having
high specific heat than that of at least air.
[0059] A circulating pump 320 for forcing flowing of the
circulating medium is installed in the circulating pipe 310. The
circulating pump 320 allows the circulating medium contained inside
the circulating pipe 310 to flow in one direction using power
applied from the outside.
[0060] A plurality of circulating pumps 320 are provided.
Preferably, the circulating pumps 320 include two or more pumps
such as fixed delivery type circulating pumps having a fixed volume
to be delivered, and variable delivery type circulating pumps whose
volume can change during an operation. In more detail, the
circulating pumps 320 include a fixed delivery type circulating
pump 320' having a fixed volume to be delivered and a variable
delivery type circulating pump 320'' whose volume to be delivered
can change.
[0061] The fixed delivery type circulating pump 320' always
supplies a predetermined volume of fluid (a circulating medium) in
one direction, and the variable delivery type circulating pump
320'' has a variable rotational speed to variably supply a volume
of the fluid.
[0062] Therefore, the variable delivery type circulating pump 320''
always operates when the ground heat exchanger 300 is used, and the
fixed delivery type circulating pump 320' is selectively used. That
is, the fixed delivery type circulating pump 320' additionally
operates when a load of the outdoor heat exchangers 140 increases
and only the variable delivery type circulating pump 320'' cannot
process the increased load.
[0063] A supplementary tank 330 for supplementing a shortage of the
circulating medium flowing through the circulating pipe 310 is
further provided to the circulating pipe 310. Also, a conservation
tank 340 for controlling a pressure of the circulating medium
flowing through the circulating pipe 310 is installed on one side
of the supplementary tank 330.
[0064] A hot water tank 430 is provided on one side of the hot
water heat pump 400. Water heated by heat exchange with the hot
water heat pump 400 is stored in the hot water tank 430. A hot
water pump 432 is installed between the hot water heat pump 400 and
the hot water tank 430 to force circulating water to flow.
[0065] Constructions and connections of the auxiliary heat sources
400, 450, and 460 will be described below in detail.
[0066] FIGS. 3 and 4 illustrate a geothermal air conditioning
system according to a second embodiment of the present invention.
That is, FIG. 3 is a view schematically illustrating a geothermal
air conditioning system is installed according to a second
embodiment of the present invention, and FIG. 4 is a block diagram
of a geothermal air conditioning system according to a second
embodiment of the present invention.
[0067] Referring to FIGS. 3 and 4, the geothermal air conditioning
system according to the second embodiment of the present invention
further includes a coolant distributor 500 and a circulation
distributor 510 besides the construction of the geothermal air
conditioning system according to the first embodiment of the
present invention.
[0068] That is, unlike the first embodiment, the second embodiment
includes a coolant distributor 500 provided to a connection portion
between the branch liquid pipe 210' and the branch gas pipe 212',
and the outdoor liquid pipe 210'' and the outdoor gas pipe 212'' to
control flow of coolant.
[0069] Also, a circulation distributor 510 for controlling flow of
the circulating medium is installed between the outdoor heat
exchanger 140 and the ground heat exchanger 300. The circulating
pipe 310 through which the circulating medium circulates is divided
into an outdoor circulating pipe 310' connected to the outdoor heat
exchanger 140 and a ground circulating pipe 310'' connected to the
ground heat exchanger 300. That is, the outdoor circulating pipe
310' is connected between the outdoor heat exchanger 140 and the
circulating divider 510 to guide the circulating medium. On the
other hand, the ground circulating pipe 310'' is connected between
the ground heat exchanger 300 and the circulation distributor 510
to guide the circulating medium.
[0070] In more detail, the geothermal air conditioning system
according to the second embodiment of the present invention
includes: a plurality of indoor units 200 for conditioning indoor
air; a plurality of outdoor units 100 through which coolant
circulates; a plurality of ground heat exchangers 300 laid under
the ground to allow heat to be exchanged between ground heat and
the circulating medium circulating through the inside of the ground
heat exchangers 300; a plurality of auxiliary heat sources 400,
450, and 460 for assisting heat exchange at outdoor heat exchangers
of the outdoor units 100; the coolant distributor 500 installed
between the indoor units 200 and the outdoor units 100 to control
coolant's flow depending on an operating condition; and the
circulation distributor 510 installed between the outdoor units 100
and the ground heat exchanger 300 to control flow of the
circulating medium (water).
[0071] The coolant distributor 500 is provided within the indoor
units 200 or the outdoor units 100, or separately installed in the
outside. Also, though not shown, the coolant distributor 500
includes a plurality of valves to separately control coolant
supplied to the plurality of indoor units 200 and outdoor units
100.
[0072] In detail, the coolant distributor 500 controls coolant
supplied to the indoor units 200 depending on a user's setting or
respective conditions of indoor spaces requiring air
conditioning.
[0073] Of course, though not shown, a control unit is provided on
one side of the coolant distributor 500 to control respective
valves (not shown) of the coolant distributor 500, and control
opening/closing of the branch liquid pipes 210' and the branch gas
pipes 212' connected to the indoor units 200. That is, the coolant
distributor 500 controls coolant flowing into the indoor units 200
depending on a user's setting, or automatically controls coolant's
flow depending on states of respective indoor spaces in which the
indoor units 200 are installed.
[0074] Also, the coolant distributor 500 also controls coolant
supplied to the outdoor units 100. That is, all or some of the
outdoor units 100 are selectively used depending on a load applied
to the indoor unit 200.
[0075] Meanwhile, according to the second embodiment, the outdoor
units 100 are individually connected to the coolant distributor
500. That is, the outdoor liquid pipes 210'' and the outdoor gas
pipes 212'' are individually and directly connected to the coolant
distributor 500.
[0076] Therefore, the coolant distributor 500 controls
opening/closing of the outdoor liquid pipes 210'' and the outdoor
gas pipes 212'' to control coolant flowing through the outdoor
units 100. Also, a high-low pressure common pipe 214 is connected
also between the outdoor units 100 such that the outdoor units 100
communicate with each other to maintain balance of coolant between
two or more outdoor units 100.
[0077] The circulation distributor 510 is provided within the
outdoor unit 100 or separately installed in the outside. Also, the
circulation distributor 510 includes a plurality of valves to
individually control flow of the circulating medium supplied to the
plurality of outdoor units 100 and ground heat exchangers 300.
[0078] In more detail, the circulation distributor 510 controls
coolant supplied to the ground heat exchangers 300 depending on a
user's setting or load of the outdoor heat exchanger 140.
[0079] Of course, though not shown, a circulation control unit is
provided on one side of the circulation distributor 510 to control
respective valves (not shown) of the circulation distributor 510 to
the circulating medium (water) flowing through the outdoor
circulating pipe 310' and the ground circulating pipe 310''. That
is, the circulation distributor 510 controls a circulating medium
flowing into the outdoor heat exchangers 140 depending on a user's
setting, or individually controls the circulating medium flowing
through the plurality of outdoor heat exchangers 140 depending on
whether the outdoor heat exchangers 140 operate or not.
[0080] Also, the circulation distributor 510 controls also a
circulating medium supplied to the plurality of ground heat
exchangers 300. That is, all or some of the ground heat exchangers
300 are selectively used depending on load applied to the outdoor
heat exchangers 140. In other words, the circulation distributor
510 controls flow of the circulating medium by controlling the
ground circulating pipes 310'' connected to the ground heat
exchangers 300 depending on loads of the outdoor heat exchangers
140.
[0081] Since inner constructions of the outdoor units 100 and the
indoor units 200, and the plurality of the auxiliary heat sources
400, 450, and 460 are the same as those of the first embodiment,
detailed descriptions thereof will be omitted.
[0082] FIG. 5 schematically illustrates a construction of an
outdoor unit, which is a crucial part of a geothermal air
conditioning system according to the present invention. One of
plurality of outdoor units will be exemplarily described below for
convenience.
[0083] Referring to FIG. 5, a plurality of compressors 120 and 120'
are installed inside the outdoor unit 100. The compressors 120 and
120' compress coolant to change the coolant to coolant of high
temperature and high pressure. That is, a constant-speed compressor
120 operating in a constant speed, and an inverter compressor 120'
which is a variable speed heat pump, are installed.
[0084] A coolant sprayer 120a is installed at an entry of the
compressors 120 and 120'. The coolant sprayer 120a supplies a
coolant when the compressors 120 and 120' are overheated depending
on their operating states to prevent damages of the compressors 120
and 120'. The coolant used here may be the coolant discharged from
the outdoor heat exchanger 140 that will be described below.
[0085] Also, a fluid uniform pipe 121 is installed between the
constant-speed compressor 120 and the inverter compressor 120' to
allow the constant-speed compressor 120 to communicate with the
inverter compressor 120'. Therefore, when fluid shortage is
generated at one compressor on either side, the fluid shortage is
compensated for by the other compressor, so that damages of the
compressors 120 and 120' are prevented.
[0086] Scroll compressors having low noise and excellent efficiency
are used as the compressors 120 and 120', and particularly, the
inverter compressor 120' is an inverter scroll compressor whose
number of revolutions is controlled depending on a load. Therefore,
when a few indoor units 200 are used and a small load is applied,
the inverter compressor 120' is operated first. Until the load
gradually increases and is not handled by the inverter compressor
120' alone, the constant-speed compressor 120 is not operated.
[0087] Compressor discharge temperature sensors 120b and 120'b for
measuring temperature of coolant discharged from the compressors
120 and 120' and oil separators 122 are provided exits of the
constant-speed compressor 120 and the inverter compressor 120',
respectively. The oil separators 122 filter oil mixed in coolant
discharged from the compressors 120 and 120' to allow the filtered
oil to be collected to the compressors 120 and 120'.
[0088] That is, oil used for cooling down friction heat generated
during operations of the compressors 120 and 120' is discharged
together with the coolant to the exits of the compressors 120 and
120'. The oil included in the coolant is separated by the oil
separator 122 and collected to the compressors 120 and 120' via an
oil collecting pipe 123.
[0089] A check valve 122' is further installed at an exit of the
oil separator 122 to prevent coolant from flowing backward. That
is, in the case where one of the constant-speed compressor 120 and
the inverter compressor 120' is operated, the check valve 122'
allows compressed coolant not to flow backward into the compressors
120 and 120' not in use.
[0090] The oil separator 122 is formed to communicate with a
four-way valve 124 via a pipe. The four-way valve 124 is installed
to change a flowing direction of coolant depending on
cooling/heating cycles. Respective ports of the four-way valve 124
are connected to exits (or the oil separators) of the compressors
120 and 120', entries (or the accumulators) of the compressors 120
and 120', the outdoor heat exchanger 140, and the indoor heat
exchanger 200.
[0091] Therefore, coolant discharged from the constant-speed
compressor 120 and the inverter compressor 120' is collected to one
place and flows into the four-way valve 124. A high pressure sensor
124' is installed at an entry of the four-way valve 124 to check
pressure of coolant discharged from the compressors 120 and
120'.
[0092] Meanwhile, a hot gas pipe 125 is installed across the
four-way valve 124 to allow a portion of coolant flowing from the
oil separator 122 to the four-way valve 124 to directly flow into
the accumulator 132 which will be described below.
[0093] The hot gas pipe 125 allows high pressure coolant from
discharge ports of the compressors 120 and 120' to directly flow to
the entries of the compressors 120 and 120' in the case where
pressure of low pressure coolant flowing to the accumulator 132
needs to be raised during an operation of the air conditioner. A
hot gas valve 125', which is a bypass valve, is installed in the
hot gas pipe 125 to open/close the hot gas pipe 125.
[0094] Also, an overcooler 130 is provided inside the outdoor unit
100. The overcooler 130 is an overcooling means for cooling down
even more the coolant heat-exchanged at the outdoor heat exchanger
140 which will be described below. The overcooler 130 is formed at
an arbitrary position of the outdoor liquid pipe 210'' connected to
an exit of the outdoor heat exchanger 140.
[0095] The overcooler 130 may be a double pipe. That is, the
outdoor liquid pipe 210'' is provided inside the overcooler 130,
and a reverse transfer pipe 130' is formed side the overcooler 130.
The reverse transfer 130' branches from an exit of the overcooler
130. An overcooling expansion valve 130'a for cooling down coolant
through expansion of the coolant is installed in the reverse
transfer pipe 130'.
[0096] With this construction, a portion of coolant discharged from
the overcooler 130 flows into the reverse transfer pipe 130' and is
cooled down while it passes through the overcooling expansion valve
130'a, and inner coolant is cooled down even more while the cooled
coolant flows through the overcooler 130 backward. The coolant
flowing backward from the overcooler 130 is supplied back to the
accumulator 132 and circulated.
[0097] Meanwhile, a liquid pipe temperature sensor 130a is
installed at an exit of the overcooler 130 to measure temperature
of coolant discharged from the outdoor unit 100. An overcooling
entry sensor 130'b is provided to an exit of the overcooling
expansion valve 130'a to measure temperature of coolant flowing to
the overcooler 130. An overcooling exit sensor 130'c is provided to
the reverse transfer pipe 130' through which coolant flowing
backward from the overcooler 130 flows.
[0098] Therefore, coolant that has passed through the outdoor heat
exchanger 140 flows through a central portion, and low temperature
coolant expanded by an expansion valve (not shown) flows in the
outside to cool down temperature of coolant even more.
[0099] A drier 131 is installed on one side of the overcooler 130,
i.e., on one side of the outdoor liquid pipe 210'' through which
coolant discharged from the outdoor heat exchanger 140 is guided to
the indoor unit 200. The drier 131 removes humidity contained in
coolant flowing through the outdoor liquid pipe 210''.
[0100] The accumulator 132 is installed between the constant-speed
compressor 120 and the inverter compressor 120'. The accumulator
132 filters liquid coolant to allow only gas coolant to flow into
the compressors 120 and 120'.
[0101] When a portion of coolant flowing from the indoor unit 200
that is not evaporated but remains in a liquid state directly flows
into the compressors 120 and 120', a load applied to the
compressors 120 and 120' changing coolant to high temperature and
high pressure gas coolant increases to cause damages of the
compressors 120 and 120'.
[0102] Therefore, since a portion of coolant flowing into the
accumulator 132 that is not evaporated but remains in a liquid
state is relatively heaver than gas coolant, the liquid coolant is
stored in a lower portion of the accumulator 132, and only the gas
coolant flows into the compressors 120 and 120'. Meanwhile, an
inflow pipe temperature sensor 132' for measuring temperature of
coolant flowing from the outside, and a low pressure sensor 132''
for measuring pressure of coolant are provided to an entry of the
accumulator 132.
[0103] The outdoor heat exchanger 140 is provided inside the
outdoor unit 100. The outdoor heat exchanger 140 allows heat to be
exchanged between coolant flowing through the outdoor heat
exchanger 140 and the circulating medium flowing through the
circulating pipe 310. The outdoor heat exchanger 140 may be a
water-cooled heat exchanger.
[0104] Though not shown, the outdoor heat exchanger 140 that is a
water-cooled heat exchanger may be a plate-type heat exchanger
formed by stacking a plurality of thin plates alternately.
Therefore, coolant flows through the inside of some of the thin
plates, and the circulating medium flows through the inside of the
rest of the thin plates. That is, since the thin plates through
which the coolant and the circulating medium flow are stacked
alternately, the coolant and the circulating medium exchange heat
while they flow in directions intersecting each other in the inside
of respective thin plates.
[0105] FIG. 6 illustrates in more detail a construction and
connections of the auxiliary heat sources 400, 450, and 460. Here,
one of ground heat exchangers is exemplarily described for
convenience. Therefore, illustration of the circulation distributor
510 will be omitted.
[0106] Referring to FIG. 6, a coolant pipe and the circulating pipe
310 that communicate with the indoor heat exchanger 202 are
connected to the outdoor heat exchanger 140 of the outdoor unit
100. That is, the outdoor liquid pipe 210'', the outdoor gas pipe
212'', and the circulating pipe 310 are connected to the outdoor
heat exchanger 140.
[0107] Therefore, heat is exchanged between coolant flowing through
the outdoor liquid pipe 210'', the outdoor gas pipe 212'', and a
circulating medium (water) flowing through the circulating pipe
310. The circulating pipe 310 is formed to constitute a closed loop
on the whole to allow the inner circulating medium to circulate
constantly while it is isolated from the outside.
[0108] The ground heat exchanger 300 is laid deep under the ground
to allow heat to be exchanged between ground heat and the
circulating medium flowing through the circulating pipe 310. That
is, the ground heat exchanger 300 may be laid under the ground up
to 1-200 m. A depth at which the ground heat exchanger 300 is laid
changes depending on climate of an installation area. The ground
heat exchanger 300 may be laid at a depth that can always maintain
an annual average temperature of that area.
[0109] A plurality of ground heat exchangers 300 can be provided.
The ground heat exchanger 300 may be formed in a zigzag shape bent
a plurality of number of times as illustrated.
[0110] As described above, the circulating pipe 310 is connected
between the ground heat exchanger 300 and the outdoor heat
exchanger 140 to allow the circulating medium (water) to flow. The
circulating pipe 310 includes a supply pipe 312 allowing the
circulating medium to flow into the ground heat exchanger 300, and
a return pipe 314 allowing the circulating medium that has passed
through the ground heat exchanger 300 to return to the outdoor heat
exchanger 140.
[0111] The return pipe 314 is provided with a circulation
temperature sensor 316. In more detail, the circulating temperature
sensor 316 is installed at an exit of the ground heat exchanger 300
to measure temperature of the circulating medium that has passed
through the ground heat exchanger 300. A temperature value measured
by the circulating temperature sensor 316 is delivered to a control
unit (not shown) controlling the system on the whole.
[0112] The hot water heat pump 400 is used in cooperation with the
ground heat exchanger 300, or selectively used. That is, only the
hot water heat pump 400 can be used for heat exchange of the
outdoor heat exchanger 140 without use of the ground heat exchanger
300.
[0113] A heat pump supply pipe 402 and a heat pump return pipe 402'
are connected between the circulating pipe 310 and the hot water
heat pump 400 to guide flow of the circulating medium (water). In
more detail, the heat pump supply pipe 402 branches from the supply
pipe 312 to guide the circulating medium to the hot water heat pump
400. The heat pump return pipe 402' branches from the return pipe
314 to guide the circulating medium returning to the return pipe
314 after having passed through the hot water heat pump 400.
[0114] A heat pump supply valve 404 is provided to a connection
portion between the supply pipe 312 and the heat pump supply pipe
402. A hot water return valve 404' is provided to a connection
portion between the return pipe 314 and the heat pump return pipe
402'. Each of the heat pump supply valve 404 and the hot water
return valve 404' is a three-way valve that can control fluid flow
of three directions.
[0115] Therefore, the heat pump supply valve 404 controls the
circulating medium coming from the outdoor heat exchanger 140 and
flowing through the supply pipe 312 to be supplied to both the
ground heat exchanger 300 and the hot water heat pump 400, or to be
supplied to one of the ground heat exchanger 300 and the hot water
heat pump 400.
[0116] A hot water temperature sensor 406 is installed in the heat
pump return pipe 402'. That is, the hot water temperature sensor
406 is installed at an exit of the hot water heat pump 400 to
measure temperature of the circulating medium discharged from the
hot water heat pump 400 via the heat pump return pipe 402'. The hot
water temperature sensor 406 is connected to a control unit (not
shown) to provide the measured temperature to the control unit.
[0117] Heat exchange is performed in the inside of the hot water
heat pump 400. That is, not only heat exchange with the circulating
medium, but also heat exchange with exchange water flowing through
a hot water circulating pipe 420, which will be described below, is
performed.
[0118] The hot water tank 430 is connected to one side (the right
side in FIG. 6) of the hot water heat pump 400. Also, the hot water
circulating pipe 420 constituting a closed loop is connected
between a hot water condenser 412 and the hot water tank 430.
Exchange water circulates through the hot water circulating pipe
420. Therefore, heat exchange is performed while the exchange water
flowing through the hot water circulating pipe 420 passes through
the hot water condenser 412. Exchange water becomes hot by the heat
exchange flows into the hot water tank 430 via the hot water
circulating pipe 420 to exchange heat with water stored in the hot
water tank 430. In this way, the water stored in the hot water tank
430 is heated.
[0119] The hot water pump 432 is installed in the hot water
circulating pipe 420. The hot water pump 432 is operated by
external power to allow exchange water flowing through the hot
water circulating pipe 420 to flow constantly in one direction.
[0120] The boiler 450 is connected to the circulating pipe 310 to
heat the circulating medium. That is, the boiler 450 is connected
to the return pipe 314 of the circulating pipe 310.
[0121] In more detail, the boiler 450 heats the circulating medium
using energy supplied from the outside. A boiler supply pipe 452
and a boiler return pipe 452' are formed between the boiler 450 and
the return pipe 314 to communicate each other.
[0122] The boiler supply pipe 452 is a passage allowing the
circulating medium flowing through the return pipe 314 to flow into
the boiler 450. The boiler return pipe 452' is a passage allowing
the circulating medium that has passed through the boiler 450 to
return to the return pipe 314.
[0123] A boiler supply valve 454 and a boiler return valve 454' are
installed at connection portions between the return pipe 314 and
the boiler supply pipe 452, and between the return pipe 314 and the
boiler return pipe 452', respectively. Like the above-described
heat pump supply valve 404 and hot water return valve 404', each of
the boiler supply valve 454 and the boiler return valve 454' may be
a three-way valve that can control fluid flow of three directions.
Therefore, supply of the circulating medium to the boiler 450 is
controlled depending on opening/closing of the boiler supply valve
454 and the boiler return valve 454'.
[0124] A boiler temperature sensor 456 is installed in the boiler
return pipe 452'. That is, the boiler temperature sensor 456
measures temperature of the circulating medium that has passed
through the boiler 450. The temperature measured by the boiler
temperature sensor 456 is delivered to the control unit.
[0125] The cooling tower 460 is connected to the return pipe 314.
The cooling tower 460 cools down the circulating medium using
contact with air. Since the cooling tower 460 is a device used for
cooling down cooling water in factories, detailed description
thereof is omitted.
[0126] A cooling tower supply pipe 462 and a cooling tower return
pipe 462' are formed between the return pipe 314 and the cooling
tower 460 to communicate with each other. The cooling tower supply
pipe 462 is a passage allowing the circulating medium flowing
through the return pipe 314 to flow into the cooling tower 460. The
cooling tower return pipe 462' is a passage allowing the
circulating medium that has passed through the cooling tower 460 to
return to the return pipe 314.
[0127] A cooling tower supply valve 464 and a cooling tower return
valve 464' are installed at connection portions between the return
pipe 314 and the cooling tower supply pipe 462, and between the
return pipe 314 and the cooling tower return pipe 462',
respectively. Like the above-described heat pump supply valve 404
and hot water return valve 404', each of the cooling tower supply
valve 464 and the cooling tower return valve 464' may be a
three-way valve that can control fluid flow of three directions.
Therefore, supply of the circulating medium to the cooling tower
460 is controlled depending on opening/closing of the cooling tower
supply valve 464 and the cooling tower return valve 464'.
[0128] A cooling temperature sensor 466 is installed in the cooling
tower return pipe 462'. That is, the cooling temperature sensor 466
measures temperature of the circulating medium that has passed
through the cooling tower 460. Temperature measured at the cooling
temperature sensor 466 is delivered to the control unit.
[0129] Meanwhile, a cooling pump 468 is further installed in the
cooling tower return pipe 462'. The cooling pump 468 applies
pressure in one direction (the right side in FIG. 6) so that the
circulating medium that has passed through the cooling tower 460 to
flow into the outdoor heat exchanger 140 via the return pipe 314.
That is, the circulating medium that has flowed into the cooling
tower 460 is exposed to air for heat exchange with the air, and is
collected again and allowed to flow through the cooling tower
return pipe 462'. As described above, the cooling pump 468 forces
flowing of the circulating medium flowing through the cooling tower
return pipe 462', and prevents the circulating medium from flowing
backward.
[0130] The circulating pump 320 may be installed in the return pipe
314 to force flowing of the circulating medium flowing through the
circulating pipe 310. In more detail, a plurality of circulating
pumps 320 are installed in parallel between the conservation tank
340 and the boiler 450 to force flowing of the circulating medium
in one direction (the right side in FIG. 6) as illustrated.
[0131] The supplementary tank 330 is a circulating medium storing
device for supplying the circulating medium to the circulating pipe
310. That is, the supplementary tank 330 is designed for
supplementing circulating medium that becomes insufficient by
evaporation or leakage generated while the circulating medium
passes through the circulating pipe 310.
[0132] The supplementary tank 330 is formed to communicate with
other pipes by the return pipe 314 and the supplementary pipe 332.
Also, a supplementary valve 334 is installed in the supplementary
pipe 332 to open/close the supplementary pipe 332 to control the
circulating medium supplied to the return pipe 314.
[0133] The supplementary valve 334 is manually opened/closed by a
user, or automatically opened/closed under control of the control
unit (not shown).
[0134] The conservation tank 340 is formed to communicate with
other pipes by the return pipe 314 and a conservation pipe 342 to
control pressure of the circulating medium flowing through the
circulating pipe 310. That is, the conservation tank 340 serves as
a buffer region for controlling pressure of the circulating medium
flowing through the circulating pipe 310 that changes transiently.
The conservation tank 340 is installed apart from the return pipe
314, or integrally formed in an intermediate portion of the return
pipe 314.
[0135] FIG. 7 illustrates a block diagram of the hot water heat
pump 400.
[0136] Referring to FIG. 7, a plurality of parts such as a hot
water evaporator 410 and a hot water condenser 412 where heat
exchange occurs are installed in the hot water heat pump 400. The
hot water evaporator 410 and the hot water condenser 412
communicate with each other via a hot water pipe 422. Also, hot
water coolant flows through the hot water pipe 422.
[0137] The hot water evaporator 410 and the hot water condenser 412
are heat exchangers corresponding to the outdoor heat exchanger 140
and the indoor heat exchanger 202, respectively. Each of the hot
water evaporator 410 and the hot water condenser 412 is a
water-cooled heat exchanger which exchanges heat using water, not
air. Also, the hot water coolant may be the same as the coolant
flowing between the indoor heat exchanger 202 and the outdoor heat
exchanger 140.
[0138] In more detail, the hot water evaporator 410 allows heat to
be exchanged between the circulating medium flowing through the
circulating pipe 310 and hot water coolant flowing through the hot
water pipe 422. Also, the hot water condenser 412 is a portion
where hot water coolant flowing through the hot water pipe 422
exchanges heat with exchange water circulating through the hot
water circulating pipe 420.
[0139] The hot water evaporator 410 serves as an evaporator.
Therefore, heat is exchanged between a high temperature circulating
medium and low temperature hot water coolant at the hot water
evaporator 410. Therefore, the high temperature circulating medium
is cooled down and condensed, and the low temperature hot water
coolant receives heat and evaporates to change into high
temperature coolant (preferably gas coolant).
[0140] On the other hand, the hot water condenser 412 serves as a
condenser. Therefore, heat is exchanged between high temperature
hot water coolant and low temperature exchange water at the hot
water condenser 412.
[0141] Therefore, the high temperature hot water coolant is cooled
down and condensed, and the low temperature exchange water receives
heat and evaporates to change into, preferably, high temperature
gas state.
[0142] The hot water pipe 422 is divided into a hot water liquid
pipe 422' and a hot water gas pipe 422''. Relatively high
temperature hot water coolant flows through the hot water liquid
pipe 422', and is introduced into the hot water evaporator 410 via
the hot water liquid pipe 422'. Also, relatively low pressure hot
water coolant flows through the hot water gas pipe 422''. Hot water
coolant that has passed through the hot water evaporator 410 flows
through the hot water gas pipe 422''.
[0143] The hot water gas pipe 422'' is provided with a plurality of
hot water compressors 414 and 414'. The hot water compressors 414
and 414' compress hot water coolant to change the coolant into high
temperature and high pressure coolant. The hot water compressors
414 and 414' may be a hot water constant speed compressor 414
operating in a constant speed, and a hot water inverter compressor
414', which is a variable speed heat pump.
[0144] Scroll compressors having small noise and excellent
efficiency may be used as the hot water compressors 414 and 414' as
in the above-described compressors 120 and 120', and particularly,
an inverter scroll compressor whose number of revolutions is
controlled depending on a load of the hot water condenser 412 is
used as the hot water inverter compressor 414'. Therefore, when a
load applied to the hot water condenser 412 is relatively small,
only the hot water inverter compressor 414' is operated first.
Until the load gradually increases and only the hot water inverter
compressor 414' cannot process the increased load, the hot water
constant speed compressor 414 is operated.
[0145] Hot water oil separators 416 are provided to exits of hot
water inverter compressors 414', respectively. The hot water oil
separators 416 filter oil mixed in coolant discharged from the hot
water inverter compressors 414' to allow the filtered oil to be
collected to the hot water inverter compressors 414'. That is, oil
used for cooling down friction heat generated during operations of
the hot water inverter compressors 414' is discharged together with
the coolant to the exits of the hot water inverter compressors
414'. The oil included in the coolant is separated by the hot water
oil separators 416 and collected to the hot water inverter
compressors 414' via a hot water oil collecting pipe 416'.
[0146] A hot water check valve 417 is further installed at exits of
the hot water oil separators 416 and the hot water constant speed
compressor 414 to prevent coolant from flowing backward. That is,
the hot water check valve 417 prevents hot water coolant from
flowing backward into the hot water compressors 414 and 414' that
are not in use in the case where only one of the hot water constant
speed compressor 414 and the hot water inverter compressor 414'
operates.
[0147] Coolant discharged from the hot water constant speed
compressor 414 and the hot water inverter compressor 414' joins
together at a joining valve 418, and flows into the hot water
condenser 412.
[0148] A hot water accumulator 424 is installed at entries of the
hot water constant speed compressor 414 and the hot water inverter
compressor 414' to filter liquid coolant and allow only gas coolant
to flow into the hot water compressors 414 and 414'. That is, since
a portion of hot water coolant discharged after having passed
through the hot water evaporator 410 that is not yet evaporated as
a gas but remains in a liquid state is relatively heaver than gas
hot water coolant, the liquid coolant is stored and filtered in a
lower portion of the hot water accumulator 424, and only the gas
hot water coolant in an upper portion flows into the hot water
compressors 414 and 414'.
[0149] A hot water expansion valve 426 is installed at the hot
water liquid pipe 422'. The hot water expansion valve 426 performs
the same function as that of the expansion valve 204 provided to
the indoor unit 200. The hot water expansion valve 426 reduces
pressure of hot water coolant that flows into the hot water
evaporator 410.
[0150] An operation of a geothermal air conditioning system having
the above-described construction according to the present invention
will be described below.
[0151] An operation of a geothermal air conditioning system
according to a first embodiment of the present invention will be
described.
[0152] First, flow of coolant and a circulating medium according to
the first embodiment of the present invention will be described on
the whole with reference to FIG. 8.
[0153] Since a closed loop through which coolant flows is formed
between the indoor unit 200 and the outdoor unit 100, coolant
exchanges heat while it circulates through the outdoor unit 100 and
the indoor unit 200 as illustrated in arrows.
[0154] At this point, the outdoor heat exchanger 140 is a
water-cooled heat exchanger. Therefore, heat is exchanged between
coolant circulating through the indoor unit 200 and the outdoor
unit 100, and a circulating medium (water) circulating through the
outdoor unit 100 and the ground heat exchanger 300 at the outdoor
heat exchanger 140.
[0155] In more detail, a circulating medium flowing through the
circulating pipe 310 is flowed in one direction by the circulating
pumps 320. Also, the plurality of circulating pumps 320 are
selectively used depending on an amount of a circulating medium
flowing through the circulating pipe 310 or an applied load. That
is, referring to FIG. 8, in the case where only one of the
plurality of outdoor heat exchangers 140 is used or large heat
exchange at the outdoor heat exchanger 140 is not required even
when two heat exchangers 140 are used, a load applied to the
circulating pump 320 is relatively small. Accordingly, only the
variable delivery type circulating pump 320'' of the plurality of
circulating pumps 320 is preferentially operated.
[0156] Also, the variable delivery type circulating pump 320''
discharges a different amount of a circulating medium depending on
a load. That is, as a load increases, a rotation speed of the
variable delivery type circulating pump 320'' gradually increases.
Only when the increased load is too large and the variable delivery
type circulating pump 320'' cannot process the increased load, the
fixed delivery type circulating pump 320' is operated. FIG. 8
exemplarily illustrates only the fixed delivery type circulating
pump 320' is used.
[0157] Meanwhile, coolant flowing through the indoor unit 200 and
the outdoor unit 100 flows in opposite directions depending on
cooling/heating cycles performed for indoor space. On the other
hand, a direction of the circulating medium (water) flowing through
the circulating pipe 310 is always constant and does not need to be
switched in a reverse direction. That is, the circulating medium
flowing through the circulating pipe 310 constantly flows in a
direction illustrated by arrows in FIG. 2.
[0158] Next, flow and operations of coolant flowing through the
outdoor unit 100 and the indoor unit 200 will be described in more
detail with reference to FIGS. 5 and 8.
[0159] As described above, a plurality of indoor units 200 are
connected to one outdoor unit 100 in air conditioning system
according to the present invention, and all or some of the indoor
units 200 are operated depending on a user's selection. Also, all
of the plurality of indoor units 200 operate for cooling or heating
the indoor space.
[0160] When the air conditioning system operates (for cooling the
indoor space), the outdoor LEV 102 is opened to allow coolant to
flow between the outdoor unit 100 and the indoor unit 200.
[0161] First, coolant flowing at the outdoor unit 100 will be
described. Gas coolant flowing from the indoor unit 200 passes
through the four-way valve 124 and flows into the accumulator 132.
Gas coolant from the accumulator 132 flows into the compressors 120
and 120'. Meanwhile, when coolant supplied to the compressors 120
and 120' is insufficient, or the compressors 120 and 120' are
overheated, coolant is supplied from the coolant sprayer 120a.
[0162] Coolant compressed by the compressors 120 and 120' is
discharged via a discharge port to pass through the oil separator
122. Oil contained in coolant is separated by the oil separator 122
and collected to the compressors 120 and 120' through the oil
collecting pipe 123.
[0163] That is, while coolant is compressed by the compressors 120
and 120', oil is mixed into coolant. Since the oil is in a liquid
state and coolant is in a gas state, the oil is separated by the
oil separator 122, which is a gas-liquid separator.
[0164] Meanwhile, balance of oil contained inside the both
compressors 120 and 120' is maintained by the fluid uniform pipe
121 connecting the constant-speed compressor 120 with the inverter
compressor 120'.
[0165] Coolant that has passed through the oil separator 122 passes
through the four-way valve 124 and flows into the outdoor heat
exchanger 140. Since the outdoor heat exchanger 140 serves as an
condenser (during a cooling cycle), coolant is cooled down and
changes into liquid coolant through heat exchange with the
circulating medium. The coolant that has passed through the outdoor
heat exchanger 140 is cooled down even more while it passes through
the overcooler 130.
[0166] The coolant that has passed through the overcooler 130
passes through the drier 131 for removing humidity contained in the
coolant, and flows into the indoor unit 200 via the common liquid
pipe 210. Meanwhile, a portion of coolant that has passed through
the compressors 120 and 120' may flow into other outdoor unit 100
via the high-low pressure common pipe 214.
[0167] The coolant supplied to other outdoor unit 100 via the
high-low pressure common pipe 214 flows into the outdoor heat
exchanger 140 of the outdoor unit 100 that is not in use to make
coolant pressure balanced on the whole, and allows predetermined
heat exchange to be performed even at the outdoor heat exchanger
140 of the outdoor unit 100 that is not in use.
[0168] When coolant is supplied to the indoor unit 200 via the
common liquid pipe 210, the coolant is supplied to respective
indoor units 200 in operation via the branch liquid pipes 210'
branching from the common liquid pipe 210. Also, the coolant is
reduced in pressure at the expansion valve 204, and exchanges heat
at the indoor heat exchanger 202. At this point, since the indoor
heat exchanger 202 serves as an evaporator, the coolant changes
into a low pressure gas through the heat exchange.
[0169] The coolant discharged from the indoor heat exchangers 202
passes through the branch pipes 212', and is collected at the
common gas pipe 212, and then flows into the outdoor unit 100. The
coolant that has flowed into the outdoor unit 100 via the common
gas pipe 212 and the outdoor gas pipes 212'' passes through the
four-way valve 124 and flows into the accumulator 132.
[0170] Liquid coolant that is not yet evaporated is filtered at the
accumulator 132. Only gas coolant is selected and supplied to the
compressors 120 and 120'. The above-described processes complete
one cycle.
[0171] Meanwhile, in the case where the air conditioning system
operates in a heating cycle, coolant flows in an opposite
direction, and an amount of coolant is controlled at the outdoor
LEV 102.
[0172] Next, an operation of a geothermal air conditioning system
will be described according to a second embodiment of the present
invention.
[0173] Flow of coolant and a circulating medium on the whole
according to the second embodiment of the present invention is
almost the same as that of coolant and a circulating medium
according to the second embodiment of the present invention. A most
particular difference is that coolant flowing between the plurality
of indoor units 200 and the outdoor units 100 passes through the
coolant distributor 500, and the circulating medium (water)
circulating between the outdoor heat exchanger 140 and the ground
heat exchanger 300 passes through the circulating distributor
510.
[0174] First, flow of coolant and a circulating medium according to
the second embodiment of the present invention will be described on
the whole with reference to FIG. 4.
[0175] As described above, since the coolant distributor 500 for
controlling flow of coolant is installed between the plurality of
indoor units 200 and the outdoor units 100, coolant flowing between
the indoor units 200 and the outdoor units 100 all passes through
the coolant distributor 500.
[0176] In the case where the plurality of indoor units 200 perform
the same function (e.g., cooling cycle), directions of coolant
flowing through the plurality of indoor units 200 are all the same,
and directions of coolant flowing through the plurality of outdoor
units 100 are also all the same.
[0177] At this point, the coolant distributor 500 selectively
opens/closes the branch liquid pipes 210' and the branch gas pipes
212' communicating with the plurality of indoor units 200 according
to a command of the control unit (not shown). That is, the coolant
distributor 500 allows coolant to be supplied only to an indoor
unit 200 that is in use, of the plurality of indoor units.
[0178] Also, the coolant distributor 500 controls coolant flowing
to the plurality of outdoor units 100. That is, in the case where
all of the indoor units 200 are operated and all of the outdoor
units 100 need to be operated, the coolant distributor 500 opens
all of the respective outdoor liquid pipes 210'' and outdoor gas
pipes 212'' so that coolant is supplied to all the outdoor units
100. On the other hand, in the case where only some of the
plurality of indoor units 200 are used or a load applied to the
indoor unit 200 is small, the coolant distributor 500 closes the
outdoor liquid pipes 210'' and the outdoor gas pipes 212''
connected to the some of the outdoor units 200 so that only some of
the plurality of outdoor units 100 are used.
[0179] Meanwhile, since the circulation distributor 510 is
installed between the outdoor heat exchangers 140 and the ground
heat exchangers 300, the circulation distributor 510 controls flow
of the circulating medium circulating through the plurality of
outdoor heat exchangers 140 and ground heat exchangers 300.
[0180] For example, the circulation distributor 510 selectively
opens/closes the respective outdoor circulating pipes 310'
communicating with the plurality of outdoor heat exchangers 140
according to a command of the control unit (not shown). That is,
the circulation distributor 510 allows the circulating medium not
to be supplied to the outdoor unit 100 of the plurality of outdoor
units 100, that is not in use.
[0181] Also, the circulation distributor 510 controls the
circulating medium supplied to the plurality of ground heat
exchangers 300. That is, in the case where all of the outdoor units
100 are operated and all of the ground heat exchangers 300 need to
be operated, the circulation distributor 510 opens all of the
ground circulating pipes 310'' so that coolant is supplied to all
the ground heat exchangers 300. On the other hand, in the case
where only some of the plurality of ground heat exchangers 300 can
sufficiently process a load, the circulation distributor 510 closes
some of the ground circulating pipes 310'' so that the circulating
medium is not supplied to the ground heat exchanger 300 that is not
in use.
[0182] Meanwhile, coolant flowing through the indoor unit 200 and
the outdoor unit 100 flows in opposite directions depending on
cooling/heating cycles performed for indoor space. On the other
hand, a direction of the circulating medium (water) flowing through
the circulating pipe 310 is always constant and does not need to be
switched in a reverse direction. That is, the circulating medium
flowing through the circulating pipe 310 constantly flows in a
direction illustrated by arrows in FIG. 4.
[0183] Flowing states of coolant contained in the outdoor units 100
and the indoor units 200 are the same as those of the first
embodiment.
[0184] FIG. 9 illustrates a circulating medium (water) flows
through the circulating pipe 310, and is a basic circulation
circuit of the case where a single ground heat exchanger 300 is
used. That is, FIG. 9 illustrates the plurality of auxiliary heat
sources 400, 450, and 460 are not used and the circulating medium
(water) circulates between the outdoor heat exchanger 140 and the
ground heat exchanger 300 in arrow directions.
[0185] At this point, flow of the circulating medium to the hot
water heat pump 400, the boiler 450, and the cooling tower 460 is
blocked by the heat pump supply pipe 402, the heat pump return pipe
402', the boiler supply valve 454, the boiler return valve 454',
the cooling tower supply valve 464, and the cooling tower return
valve 464'.
[0186] Therefore, the circulating medium flowing through the
circulating pipe 310 circulates counterclockwise constantly as
illustrated in arrows of FIG. 9. The flowing direction of the
circulating medium maintains a constant direction regardless of
cooling/heating cycles by the air conditioning system. That is, the
circulating medium circulates in a constant direction regardless of
whether the outdoor heat exchanger 140 serves as a condenser or an
evaporator.
[0187] In the case where the outdoor heat exchanger 140 is used as
a condenser (cooling cycle), the circulating medium flowing through
the circulating pipe 310 cools down coolant at the outdoor heat
exchanger 140. On the other hand, in the case where the outdoor
heat exchanger 140 is used as an evaporator (heating cycle), the
circulating medium flowing through the circulating pipe 310 heats
coolant at the outdoor heat exchanger 140.
[0188] Also, when the circulating medium flowing through the
circulating pipe 310 is insufficient, a user manually opens the
supplementary valve 334 to supplement a circulating medium
according to a signal of the control unit (not shown), or the
supplementary valve 334 is automatically opened/closed under
control of the control unit.
[0189] Also, the circulating pump 320 is driven using power applied
from the outside to allow the circulating medium flowing through
the circulating pipe 310 not to flow backward but to flow in one
direction (counterclockwise direction in FIG. 9) constantly.
[0190] This circulation mechanism is a simplest mechanism used by a
geothermal air conditioning system according to the present
invention. When temperature of the circulating medium measured by
the circulation temperature sensor 316 does not reach required
temperature, the auxiliary heat sources 400, 450, and 460 are
operated. That is, when temperature does not reach temperature
sufficient to cool down or heat coolant at the outdoor heat
exchanger 140, at least one of the auxiliary heat sources 400, 450,
and 460 is operated to cool down or heat the circulating
medium.
[0191] FIG. 10 illustrates flow of the circulating medium when the
hot water heat pump 400 is operated. Referring to FIG. 10, the hot
water heat pump 400 is primarily operated when an air conditioning
system of the present invention operates in a cooling cycle.
[0192] First, a solid line arrow shows the case where a circulating
medium is simultaneously supplied to both the ground heat exchanger
300 and the hot water heat pump 400. Therefore, at this point, the
heat pump supply valve 404 is completely opened to allow a
circulating medium coming from the outdoor heat exchanger 140 to
flow into both the ground heat exchanger 300 and the hot water heat
pump 400.
[0193] Also, at this point, since the hot water tank 430 operates,
exchange water flows in an inside of the hot water circulating pipe
420. Therefore, heat exchange is performed even at the hot water
condenser 412. That is, hot water coolant that passes through the
hot water condenser 412 exchanges heat with the exchange water
contained in the hot water circulating pipe 420, and is cooled
down. Accordingly, water of the hot water tank 430 is heated by the
heated exchange water to change into high temperature water.
[0194] Meanwhile, the circulating medium cooled down while it
passes through the ground heat exchanger 300 and the hot water heat
pump 400 joins again and flows into the outdoor heat exchanger 140.
Also, the cooled down circulating medium and high temperature
coolant exchange heat with each other at the outdoor heat exchanger
140, so that the coolant is cooled down and the circulating medium
is heated.
[0195] Next, a dotted line arrow shows a circulating medium passes
through only the hot water heat pump 400. That is, the circulating
medium does not flow to the ground heat exchanger 300.
[0196] At this point, the heat pump supply valve 404 blocks a
passage to the ground heat exchanger 300, and opens only a passage
to the hot water heat pump 400 to control a circulating medium
coming from the outdoor heat exchanger 140 to pass through only the
hot water heat pump 400.
[0197] Also, at this point, since the hot water tank 430 operates
as described, heat is exchanged between the circulating medium and
hot water coolant at the hot water evaporator 410, and heat is
exchanged between hot water coolant and exchange water at the hot
water condenser 412. Therefore, the circulating medium is cooled
down while it passes through the hot water heat pump 400.
Circulation and heat exchange of hot water coolant performed inside
the hot water heat pump 400 will be described below in detail.
[0198] Temperature of a circulating medium discharged after passing
through the hot water heat pump 400 is measured by the hot water
temperature sensor 406, and the measured temperature is delivered
to the control unit (not shown). Therefore, the control unit judges
whether temperature of the circulating medium coming from the hot
water heat pump 400 is sufficient temperature for cooling down
coolant at the outdoor heat exchanger 140 to determine whether to
operate other auxiliary heat source (cooling tower).
[0199] For example, when temperature of the circulating medium
coming from the hot water heat pump 400 is greater than critical
cooling temperature of coolant that should be cooled down at the
outdoor heat exchanger 140, the control unit controls the
circulating medium to pass through the cooling tower 460 to cool
down the circulating medium even more. Here, the critical cooling
temperature is temperature set to an upper limit required for
condensing gas coolant at the outdoor heat exchanger 140 during a
cooling cycle of the air conditioning system.
[0200] Also, a process by which a circulating medium that has
flowed into the outdoor heat exchanger 140 to exchange heat with
coolant is the same as that described above.
[0201] FIG. 11 exemplarily illustrates the boiler 450 operates.
That is, the boiler 450 operates in order to raise temperature of
the circulating medium coming from the ground heat exchanger 300.
At this point, the air conditioning system according to the present
invention operates in a heating cycle to heat indoor space.
[0202] As illustrated in FIG. 11, the boiler 450 operates in the
case where temperature measured by the circulation temperature
sensor 316 is not sufficiently high to heat coolant at the outdoor
heat exchanger 140, or in the case where a user intends to double
heating ability of the air conditioning system. That is, the boiler
450 is used in the case where temperature of the circulating medium
that has passed through the ground heat exchanger 300 is lower than
critical heating temperature of coolant flowing into the outdoor
heat exchanger 140, or in the case where a user wants strong
heating. Here, the critical heating temperature is temperature set
to a lower limit required for evaporating liquid coolant at the
outdoor heat exchanger 140 during a heating cycle of the air
conditioning system.
[0203] Referring to FIG. 11, in this case, the boiler supply valve
454 opens a passage of the boiler 450 to allow a circulating medium
coming from the ground heat exchanger 300 to pass through the
boiler 450.
[0204] In more detail, the control unit (not shown) blocks a right
passage of the boiler supply valve 454 and simultaneously opens a
lower passage of the boiler supply valve 454 to allow the
circulating medium that has passed through the ground heat
exchanger 300 to flow into the boiler 450 in the case where the
temperature of the circulating medium measured by the circulation
temperature sensor 316 is lower than the critical heating
temperature. Also, simultaneously, a lower passage of the boiler
return valve 454' is opened.
[0205] Also, at this point, flow of a circulating medium to the hot
water heat pump 400 and the cooling tower 460 is blocked by the
heat pump supply pipe 402, the heat pump return pipe 402', the
cooling tower supply valve 464, and the cooling tower return valve
464'.
[0206] The boiler 450 is heated by external power or energy to
increase temperature of the circulating medium. Temperature of the
circulating medium that has passed through the boiler 450 is
measured by the boiler temperature sensor 456 and delivered to the
control unit. Therefore, the control unit controls a level of
heating the circulating medium at the boiler 450 depending on the
temperature delivered from the boiler temperature sensor 456.
Therefore, temperature of the circulating medium measured at the
boiler temperature sensor 456 should be greater than the critical
heating temperature.
[0207] A circulating medium sufficiently heated (to the critical
heating temperature or more) while it passes through the boiler 450
flows into the outdoor heat exchanger 140 to exchange heat with
coolant that is to flow into the indoor unit 200. Therefore, the
circulating medium is cooled down and the coolant is heated.
[0208] FIG. 12 illustrates the cooling tower 460 is used as an
auxiliary heat source. A circulating medium is cooled down while it
passes through the cooling tower 460 when the air conditioning
system according to the present invention operates in a cooling
cycle. That is, the cooling tower 460 is used in the case where
temperature of the circulating medium that has exchanged heat at
the ground heat exchanger 300 is greater than the critical cooling
temperature of coolant that is to exchange heat at the outdoor heat
exchanger 140, or in the case where a user intends to improve a
cooling ability of the air conditioning system even more.
[0209] In more detail, the control unit controls an upper passage
of the cooling tower supply valve 464 to be opened and controls a
right passage of the cooling tower supply valve 464 to be closed,
and simultaneously, controls an upper passage of the cooling tower
return valve 464' to be opened in the case where temperature of the
circulating medium detected by the circulation temperature sensor
316 does not reach the critical cooling temperature.
[0210] Accordingly, a passage to the cooling tower 460 is opened
and the circulating medium that has passed through the ground heat
exchanger 300 flows into the cooling tower 460 via the cooling
tower supply pipe 462 and is cooled down. Also, the circulating
medium cooled down at the cooling tower 460 is flowed to the
cooling tower return pipe 462' by the cooling pump 468, and
subsequently, flows into the outdoor heat exchanger 140. At this
point, temperature of the circulating medium measured by the
cooling temperature sensor 466 should be maintained lower than the
critical cooling temperature.
[0211] A low temperature circulating medium that has flowed into
the outdoor heat exchanger 140 exchanges heat with high temperature
coolant. Therefore, the circulating medium is changed into a high
temperature circulating medium by heat exchange. The coolant is
changed into low temperature coolant by heat exchange and flows
into the indoor unit 200 to cool down an indoor space (a space for
air conditioning).
[0212] In the geothermal air conditioning system according to the
present invention, the control unit operates the plurality of
auxiliary heat sources 400, 450, and 460 on the basis of
temperature measured by the circulation temperature sensor 316.
That is, the control unit selectively or simultaneously operates
the hot water heat pump 400 or the cooling tower 460 when the
circulating medium that has passed through the ground heat
exchanger 300 needs to be further cooled down even more during a
cooling cycle. Also, the control unit controls the circulating
medium to pass through the boiler 450 when the circulating medium
that has passed through the ground heat exchanger 300 needs to be
further heated.
[0213] Meanwhile, all of the plurality of indoor units 200 can be
uniformly used for cooling or heating an indoor space. Besides, the
plurality of indoor units 200 can be operated to simultaneously
perform a cooling cycle and a heating cycle. That is, some of the
indoor units 200 can be operated for a heating cycle, and some of
the indoor units 200 can be operated for a cooling cycle.
[0214] FIG. 13 exemplarily illustrates some of the indoor units are
operated for a heating cycle, and some of the indoor units are
operated for a cooling cycle. That is, a first indoor unit 200a and
a second indoor unit 200b of indoor units illustrated in FIG. 13
are operated for a cooling cycle. A third indoor unit 200c and a
fourth indoor unit 200d of the indoor units illustrated in FIG. 13
are operated for a heating cycle. A solid line of FIG. 13 shows
flow of coolant and a circulating medium for a cooling cycle, and a
dotted line of FIG. 13 shows flow of coolant and a circulating
medium for a heating cycle.
[0215] At this point, a first outdoor unit 100a of the plurality of
outdoor units is used for a cooling cycle of the first indoor unit
200a and the second indoor unit 200b. A second outdoor unit 100b of
the plurality of outdoor units is used for a heating cycle of the
third indoor unit 200c and the fourth indoor unit 200d.
[0216] First, cooling a space (an indoor space) for air
conditioning will be described.
[0217] Coolant that has passed through the first indoor unit 200a
and the second indoor unit 200b joins at the coolant distributor
500, and flows into the first outdoor unit 100a. The coolant that
has flowed into the first outdoor unit 100a flows into a first
outdoor heat exchanger 140a to exchange heat with a circulating
medium. At this point, the coolant is cooled down and condensed by
the circulating medium.
[0218] The coolant condensed by the first outdoor heat exchanger
140a flows into the coolant distributor 500 again, and is
distributed and supplied to the first indoor unit 200a and the
second indoor unit 200b. The coolant that has flowed into the first
indoor unit 200a and the second indoor unit 200b exchanges heat
with air contained in an indoor space, and is evaporated (heated)
at a first indoor heat exchanger 202a and a second indoor heat
exchanger 202b. Therefore, the coolant emits cooling air to cool
down the space for air conditioning (a first indoor space in which
the first indoor unit is installed, and a second indoor space in
which the second indoor unit is installed) during above
process.
[0219] Also, a circulating medium that has exchanged heat with
coolant at the first outdoor heat exchanger 140a flows into a
plurality of first ground heat exchangers 300a along a first
circulating pipe 310a. In more detail, the circulating medium that
has passed through the first outdoor heat exchanger 140a is guided
along a first outdoor circulating pipe 310a', flows into the
circulating distributor 510, passes through the circulating
distributor 510, and is guided along a first ground circulating
pipe 310a'' and flows into the plurality of first ground heat
exchangers 300a.
[0220] The circulating medium that has flowed into the first ground
heat exchanger 300a is cooled down by emitting heat to the ground,
and flows into the cooling tower 460. The circulating medium is
cooled down even more by external air. The circulating medium that
has passed through the cooling tower 460 flows along the first
ground circulating pipe 310a'', passes through the circulation
distributor 510, flows along the first outdoor circulating pipe
310a', and flows into the first outdoor heat exchanger 140a
again.
[0221] Therefore, a low temperature circulating medium that has
flowed into the first outdoor heat exchanger 140a cools down
coolant that passes through the first outdoor heat exchanger 140a,
and the low temperature circulating medium itself is heated. Though
the above-described processes, the circulating medium circulates
through a complete one cycle.
[0222] Next, heating a space for air conditioning will be
described.
[0223] Coolant that has passed through the third indoor unit 200c
and the fourth indoor unit 200d joins at the coolant distributor
500, and flows into the second outdoor unit 100b. The coolant that
has flowed into the second outdoor unit 100b flows into a second
outdoor heat exchanger 140b to exchange heat with a circulating
medium. At this point, the coolant is heated and evaporated by the
circulating medium.
[0224] The coolant evaporated (heated) by the second outdoor heat
exchanger 140b flows into the coolant distributor 500 again, and is
distributed and supplied to the third indoor unit 200c and the
fourth indoor unit 200d. The coolant that has flowed into the third
indoor unit 200c and the fourth indoor unit 200d exchanges heat
with air contained in an indoor space, and is evaporated (heated)
at a third indoor heat exchanger 202c and a fourth indoor heat
exchanger 202d. Therefore, the coolant emits hot air to heat the
space for air conditioning (a third indoor space in which the third
indoor unit is installed, and a fourth indoor space in which the
fourth indoor unit is installed) during above process.
[0225] Also, a circulating medium that has exchanged heat with
coolant at the second outdoor heat exchanger 140b flows into a
plurality of second ground heat exchangers 300b along a second
circulating pipe 310b. In more detail, the circulating medium that
has passed through the second outdoor heat exchanger 140b is guided
along a second outdoor circulating pipe 310b', flows into the
circulating distributor 510, passes through the circulating
distributor 510, and is guided along a second ground circulating
pipe 310b'', and flows into the plurality of second ground heat
exchangers 300b.
[0226] The circulating medium that has flowed into the second
ground heat exchanger 300b is heated by receiving heat from the
ground, and flows into the boiler 450. The circulating medium is
heated even more at the boiler 450 and changed into a high
temperature circulating medium. The high temperature circulating
medium that has passed through the boiler 450 passes through the
circulation distributor 510, flows along the second outdoor
circulating pipe 310b', and flows into the second outdoor heat
exchanger 140b again.
[0227] Therefore, the high temperature circulating medium that has
flowed into the second outdoor heat exchanger 140b heats coolant
that passes through the second outdoor heat exchanger 140b, and the
high temperature circulating medium itself is cooled down. Though
the above-described processes, the circulating medium circulates
through another complete cycle.
[0228] Meanwhile, also according to the above-described second
embodiment, the plurality of circulating pumps 320 are all or
selectively used. That is, referring to FIG. 14, the variable
delivery type circulating pump 320'' always operates in the case
where the ground heat exchanger 300 is used, and changes its
rotation speed depending on a load applied thereto.
[0229] Also, in the case where a load applied to the variable
delivery type circulating pump 320'' gradually increases and only
the variable delivery type circulating pump 320'' cannot process
the increased load, the fixed delivery type circulating pump 320'
operates to supply a circulating medium.
[0230] As described above, according to the present invention, not
only all of the plurality of indoor units 200 can be operated for a
cooling cycle or a heating cycle, but also some of the plurality of
indoor units 200 are operated for a heating cycle, and also some of
the plurality of indoor units 200 are operated for a cooling
cycle.
[0231] Also, the above-described partial cooling cycle and partial
heating cycle can be performed by a user's selection/control, and
can be automatically performed under control of the control unit
(not shown).
[0232] That is, the control unit (not shown) determines whether to
heat or cool down respective spaces (indoor spaces) for air
conditioning according to a signal delivered from sensors (e.g.,
temperature sensors) installed at the indoor spaces. Coolant
flowing into the plurality of indoor units 200 is individually
controlled in response to a control signal from the control unit.
Also, all or some of the plurality of outdoor units 100 and the
ground heat exchangers 300 are selectively used depending on a
load.
[0233] It will be apparent to those skilled in the art that various
modifications and variations can be made in the present invention.
Thus, it is intended that the present invention covers the
modifications and variations of this invention provided they come
within the scope of the appended claims and their equivalents.
[0234] For example, the number of the ground heat exchangers 300
described or illustrated in the above respective embodiments can be
modified in various ways.
[0235] That is, though one ground heat exchanger 300 is used
according to the first embodiment, two or more ground heat
exchangers 300 can be installed in parallel or in series.
[0236] Also, the number of the ground heat exchangers 300
illustrated in FIG. 3 or 4 is not limited also in the second
embodiment, but a various number of ground heat exchangers 300 can
be connected and installed, and a separate ground distributor can
be further provided so that the plurality of ground heat exchangers
300 can be selectively used when needed.
* * * * *