U.S. patent application number 12/929394 was filed with the patent office on 2011-09-08 for heat pump system and control method thereof.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Dong Woon Jeong, Sung Goo Kim, Jae Hyuk Oh, Seong Je Wu.
Application Number | 20110214437 12/929394 |
Document ID | / |
Family ID | 44148905 |
Filed Date | 2011-09-08 |
United States Patent
Application |
20110214437 |
Kind Code |
A1 |
Jeong; Dong Woon ; et
al. |
September 8, 2011 |
Heat pump system and control method thereof
Abstract
A heat pump system which executes cooling and heating operations
of an A2A indoor unit and cooling and heating operations and a hot
water operation of an A2W indoor unit in a time division
multiplexing (TDM) method, and a control method thereof. Further,
the heat pump system solves shortage of a refrigerant during a
heating operation of the A2A indoor unit or the A2W indoor unit
when the TDM method is used. Therefore, the heat pump system
includes a control unit to alternately operate the A2A indoor unit
or the A2W indoor unit, upon judging that a simultaneous operating
condition of the A2A indoor unit or the A2W indoor unit is
satisfied. The heat pump system further includes a refrigerant
distribution unit to circulate a refrigerant selectively to the A2A
indoor unit or the A2W indoor unit.
Inventors: |
Jeong; Dong Woon;
(Yongin-si, KR) ; Kim; Sung Goo; (Seoul, KR)
; Oh; Jae Hyuk; (Seongnam-si, KR) ; Wu; Seong
Je; (Anyang-si, KR) |
Assignee: |
SAMSUNG ELECTRONICS CO.,
LTD.
Suwon-si
KR
|
Family ID: |
44148905 |
Appl. No.: |
12/929394 |
Filed: |
January 20, 2011 |
Current U.S.
Class: |
62/79 ; 62/159;
62/190 |
Current CPC
Class: |
F25B 2313/003 20130101;
F25B 2313/02742 20130101; F25B 13/00 20130101; F25B 25/005
20130101; F25B 2313/0233 20130101 |
Class at
Publication: |
62/79 ; 62/190;
62/159 |
International
Class: |
F25B 30/02 20060101
F25B030/02; F25D 17/00 20060101 F25D017/00; F25B 29/00 20060101
F25B029/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 2, 2010 |
KR |
10-2010-18648 |
Claims
1. A heat pump system comprising: an outdoor unit including an
outdoor air heat exchanger; at least one first indoor unit
including an indoor air heat exchanger; at least one second indoor
unit including an indoor water-refrigerant heat exchanger; a
refrigerant circulation pipe unit connected to the outdoor unit,
the at least one first indoor unit, and the at least one second
indoor unit to circulate a refrigerant; and a control unit to
control the at least one first indoor unit and the at least one
second indoor unit so as to be alternately operated, upon judging
that a simultaneous operating condition of the at least one first
indoor unit and the at least one second indoor unit is
satisfied.
2. The heat pump system according to claim 1, wherein a capacity of
the at least one first indoor unit and a capacity of the at least
one second indoor unit are equal to a capacity of the outdoor
unit.
3. The heat pump system according to claim 1, wherein the sum total
of a capacity of the at least one first indoor unit and a capacity
of the at least one second indoor unit is in the range of 50-130%
of a capacity of the outdoor unit.
4. The heat pump system according to claim 1, wherein the outdoor
unit further includes a variable capacity compressor having a
variable capacity.
5. The heat pump system according to claim 4, wherein the control
unit controls the outdoor unit such that an output of the outdoor
unit is not automatically varied but the outdoor unit is operated
according to the maximum capacity of the operating one of the at
least one first indoor unit and the at least one second indoor
unit.
6. The heat pump system according to claim 1, further comprising: a
water circulation pipe unit to circulate water having exchanged
heat with the refrigerant in the at least one second indoor unit; a
hot water tank connected to the water circulation pipe unit; a
first sub heater to heat the water circulation pipe unit; and a
second sub heater to heat the hot water tank, wherein the control
unit executes a heating operation or a hot water operation of the
at least one second indoor unit using at least one of the first sub
heater and the second sub heater and controls the outdoor unit so
as to execute a cooling operation of the at least one first indoor
unit, if the heating operation or the hot water operation of the at
least one second indoor unit is requested during the cooling
operation of the at least one first indoor unit.
7. The heat pump system according to claim 1, further comprising an
input unit, through which an operation mode of the at least one
first indoor unit and the at least one second indoor unit is input,
wherein the control unit controls the at least one first indoor
unit and the at least one second indoor unit so as to be
alternately operated under the condition that the operation of the
at least one first indoor unit or the at least one second indoor
unit is limited to a cooling mode or a heating mode according to
the cooling mode or the heating mode input through the input
unit.
8. The heat pump system according to claim 1, further comprising an
input unit, through which an operation mode of the at least one
first indoor unit and the at least one second indoor unit is input,
wherein the control unit controls the at least one first indoor
unit and the at least one second indoor unit so as to be operated
in a hot water operation mode only, if the hot water operation mode
is input through the input unit.
9. The heat pump system according to claim 8, wherein, if the at
least one first indoor unit is operating when the hot water
operation mode is input through the input unit, the control unit
operates the at least one first indoor unit in a rapid cooling mode
or a rapid heating mode to enable the at least one first indoor
unit to reach a target temperature and then controls the at least
one first indoor unit and the at least one second indoor unit so as
to be operated in the hot water operation mode only.
10. The heat pump system according to claim 9, wherein the control
unit stops the operation in the hot water operation mode, if a
signal to stop the hot water operation mode is input through the
input unit or water in a hot water tank reaches a hot water set
temperature.
11. The heat pump system according to claim 1, wherein the control
unit simultaneously operates the at least one first indoor unit and
the at least one second indoor unit, upon judging that the sum
total of a capacity required by the at least one first indoor unit
and a capacity required by the at least one second indoor unit is
less than a capacity of the outdoor unit.
12. The heat pump system according to claim 1, wherein the control
unit preferentially operates any one of the at least one first
indoor unit and the at least one second indoor unit, upon judging
that a simultaneous operating condition of the at least one first
indoor unit and the at least one second indoor unit is
satisfied.
13. The heat pump system according to claim 12, wherein the control
unit preferentially operates the at least one first indoor unit,
upon judging that the simultaneous operating condition of the at
least one first indoor unit and the at least one second indoor unit
is satisfied.
14. The heat pump system according to claim 13, wherein the control
unit changes the operation of the at least one first indoor unit
into the operation of the at least one second indoor unit, upon
judging that the at least one first indoor unit reaches a first
target temperature during the preferential operation of the at
least one first indoor unit or the at least one first indoor unit
is operated for a first set time.
15. The heat pump system according to claim 14, wherein the control
unit stops the operation of the at least one second indoor unit,
upon judging that the at least one second indoor unit reaches a
second target temperature during the operation of the at least one
second indoor unit or the at least one second indoor unit is
operated for a second set time.
16. The heat pump system according to claim 15, wherein the control
unit lowers the first target temperature by a reference value, if
the first target temperature and the second target temperature are
equal, the at least one second indoor unit is not operated, and the
number of on/off of the operation of the at least one first indoor
unit reaches a designated number.
17. A control method of a heat pump system, which has an outdoor
unit including an outdoor air heat exchanger, at least one first
indoor unit including an indoor air heat exchanger, at least one
second indoor unit including an indoor water-refrigerant heat
exchanger, and a water circulation pipe unit connected to the
outdoor unit, the at least one first indoor unit, and the at least
one second indoor unit to circulate a refrigerant, comprising:
alternately operating the at least one first indoor unit and the at
least one second indoor unit, upon judging that a simultaneous
operating condition of the at least one first indoor unit and the
at least one second indoor unit is satisfied.
18. The control method according to claim 17, wherein any one of
the at least one first indoor unit and the at least two indoor unit
is preferentially operated, upon judging that the simultaneous
operating condition of the at least one first indoor unit and the
at least one second indoor unit is satisfied.
19. The control method according to claim 18, wherein the at least
one first indoor unit is preferentially operated, upon judging that
the simultaneous operating condition of the at least one first
indoor unit and the at least one second indoor unit is
satisfied.
20. A heat pump system comprising: at least one first indoor unit
including an indoor air heat exchanger and a first expander; at
least one second indoor unit including an indoor water-refrigerant
heat exchanger and a second expander; an outdoor unit including an
outdoor air heat exchanger, a compressor, and a third expander; a
refrigerant circulation pipe unit connected to the at least one
first indoor unit, the at least one second indoor unit, and the
outdoor unit to circulate a refrigerant; a refrigerant distribution
unit to circulate the refrigerant selectively to the at least one
first indoor unit and the at least one second indoor unit; and a
control unit controlling the at least one first indoor unit and the
at least one second indoor unit so as to be alternately operated,
upon judging that a simultaneous operating condition of the at
least one first indoor unit and the at least one second indoor unit
is satisfied.
21. The heat pump system according to claim 20, wherein the
refrigerant distribution unit includes a four-way valve.
22. The heat pump system according to claim 21, wherein the
refrigerant distribution unit further includes check valves.
23. The heat pump system according to claim 20, wherein the
refrigerant distribution unit includes a three-way valve.
24. The heat pump system according to claim 20, wherein the control
unit executes a preliminary heating operation by driving the
compressor, under the condition that the expander of one of the at
least one first indoor unit and the at least one second indoor
unit, a heating operation of which is executed, is closed and the
expander of the other one of the at least one first indoor unit and
the at least one second indoor unit is opened, before the heating
operation of the one of the at least one first indoor unit and the
at least one second indoor unit is executed.
25. A control method of a heat pump system, which has at least one
first indoor unit including an indoor air heat exchanger and a
first expander, at least one second indoor unit including an indoor
water-refrigerant heat exchanger and a second expander, an outdoor
unit including an outdoor air heat exchanger, a compressor, and a
third expander, a refrigerant circulation pipe unit connected to
the at least one first indoor unit, the at least one second indoor
unit, and the outdoor unit to circulate a refrigerant, and a
refrigerant distribution unit to circulate the refrigerant
selectively to the at least one first indoor unit and the at least
one second indoor unit, comprising: executing a preliminary heating
operation by driving the compressor, under the condition that the
expander of one of the at least one first indoor unit and the at
least one second indoor unit, a heating operation of which is
executed, is closed and the expander of the other one of the at
least one first indoor unit and the at least one second indoor unit
is opened, before the heating operation of the one of the at least
one first indoor unit and the at least one second indoor unit is
executed.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent
Application No. 2010-0018648, filed on Mar. 2, 2010 in the Korean
Intellectual Property Office, the disclosure of which is
incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] Embodiments relate to a heat pump system in which a
plurality of indoor units is connected to an outdoor unit so as to
cool or heat air in indoor spaces or to supply hot water, and a
control method thereof.
[0004] 2. Description of the Related Art
[0005] A heat pump system uses heat of a heat pump, including a
compressor, an outdoor air exchanger, an expander, a
water-refrigerant heat exchanger, and an indoor exchanger, to heat
an indoor floor or to cool and heat indoor air.
[0006] In general, heat pump systems are divided into a system
using an air to air heat pump (hereinafter, referred to as an "A2A
heat pump") including a refrigerant pipe through which a cold or
hot refrigerant passes and a fan generating air so as to cool or
heat an indoor space, and a system using an air to water heat pump
(hereinafter, referred to as an "A2W heat pump") to cool or heat an
indoor space or to heat water stored in a water tank using a water
pipe through which cold or hot water passes.
[0007] If the above two heat pumps are combined into one
multi-functional product, a system to which heat recovery (HR) is
applied is used so as to cool an indoor space or to supply hot
water. Here, a separate unit to carry out conversion between a
cooling operation and a heating operation is additionally used and
thus raises manufacturing costs of the product, and a separate
program for the HR is operated and thus increases complexity of the
product. Further, the sum total of a capacity of the A2A heat pump
and a capacity of the A2W heat pump becomes equal to a capacity of
an outdoor unit, and thus the A2A heat pump and the A2W heat pump
may not be installed in the same space or an outdoor unit having a
greater capacity may be required.
SUMMARY
[0008] Therefore, it is an aspect to provide a heat pump system
which executes cooling and heating operations of an A2A indoor unit
and cooling and heating operations and a hot water operation of an
A2W indoor unit through a time division multiplexing (TDM) method,
if necessary, without any additional unit, and a control method
thereof.
[0009] It is another aspect to provide a heat pump system which
executes a preliminary heating operation to solve shortage of a
refrigerant during a heating operation of an A2A indoor unit or an
A2W indoor unit when a time division multiplexing (TDM) method is
used, and a control method thereof.
[0010] Additional aspects will be set forth in part in the
description which follows and, in part, will be apparent from the
description, or may be learned by practice of the invention.
[0011] In accordance with one aspect, a heat pump system includes
an outdoor unit including an outdoor air heat exchanger, at least
one first indoor unit including an indoor air heat exchanger, at
least one second indoor unit including an indoor water-refrigerant
heat exchanger, a refrigerant circulation pipe unit connected to
the outdoor unit, the at least one first indoor unit, and the at
least one second indoor unit to circulate a refrigerant, and a
control unit controlling the at least one first indoor unit and the
at least one second indoor unit so as to be alternately operated,
upon judging that a simultaneous operating condition of the at
least one first indoor unit and the at least one second indoor unit
is satisfied.
[0012] A capacity of the at least one first indoor unit and a
capacity of the at least one second indoor unit may be equal to a
capacity of the outdoor unit, or the sum total of the capacity of
the at least one first indoor unit and the capacity of the at least
one second indoor unit may be in the range of 50-130% of the
capacity of the outdoor unit.
[0013] The outdoor unit may further include a variable capacity
compressor having a variable capacity. The control unit may control
the outdoor unit such that an output of the outdoor unit is not
automatically varied but the outdoor unit is operated according to
the maximum capacity of the operating one of the at least one first
indoor unit and the at least one second indoor unit.
[0014] The heat pump system may further include a water circulation
pipe unit to circulate water having exchanged heat with the
refrigerant in the at least one second indoor unit, a hot water
tank connected to the water circulation pipe unit, a first sub
heater to heat the water circulation pipe unit, and a second sub
heater to heat the hot water tank, and the control unit may execute
a heating operation or a hot water operation of the at least one
second indoor unit using at least one of the first sub heater and
the second sub heater and control the outdoor unit so as to execute
a cooling operation of the at least one first indoor unit, if the
heating operation or the hot water operation of the at least one
second indoor unit is requested during the cooling operation of the
at least one first indoor unit.
[0015] The heat pump system may further include an input unit,
through which an operation mode of the at least one first indoor
unit and the at least one second indoor unit is input, and the
control unit may control the at least one first indoor unit and the
at least one second indoor unit so as to be alternately operated
under the condition that the operation of the at least one first
indoor unit or the at least one second indoor unit is limited to a
cooling mode or a heating mode according to the cooling mode or the
heating mode input through the input unit.
[0016] The control unit may control the at least one first indoor
unit and the at least one second indoor unit so as to be operated
in a hot water operation mode only, if the hot water operation mode
is input through the input unit. If the at least one first indoor
unit is operating when the hot water operation mode is input
through the input unit, the control unit may operate the at least
one first indoor unit in a rapid cooling mode or a rapid heating
mode to enable the at least one first indoor unit to reach a target
temperature and then control the at least one first indoor unit and
the at least one second indoor unit so as to be operated in the hot
water operation mode only. Here, the control unit may stop the
operation in the hot water operation mode, if a signal to stop the
hot water operation mode is input through the input unit or water
in a hot water tank reaches a hot water set temperature.
[0017] The control unit may simultaneously operate the at least one
first indoor unit and the at least one second indoor unit, upon
judging that the sum total of a capacity required by the at least
one first indoor unit and a capacity required by the at least one
second indoor unit is less than a capacity of the outdoor unit.
[0018] The control unit may preferentially operate any one of the
at least one first indoor unit and the at least one second indoor
unit, upon judging that a simultaneous operating condition of the
at least one first indoor unit and the at least one second indoor
unit is satisfied. Here, the control unit may preferentially
operate the at least one first indoor unit.
[0019] The control unit may change the operation of the at least
one first indoor unit into the operation of the at least one second
indoor unit, upon judging that the at least one first indoor unit
reaches a first target temperature during the preferential
operation of the at least one first indoor unit or the at least one
first indoor unit is operated for a first set time.
[0020] Further, the control unit may stop the operation of the at
least one second indoor unit, upon judging that the at least one
second indoor unit reaches a second target temperature during the
operation of the at least one second indoor unit or the at least
one second indoor unit is operated for a second set time.
[0021] The control unit may lower the first target temperature by a
reference value, if the first target temperature and the second
target temperature are equal, the at least one second indoor unit
is not operated, and the number of on/off of the operation of the
at least one first indoor unit reaches a designated number.
[0022] In accordance with another aspect, a control method of a
heat pump system, which has an outdoor unit including an outdoor
air heat exchanger, at least one first indoor unit including an
indoor air heat exchanger, at least one second indoor unit
including an indoor water-refrigerant heat exchanger, and a
refrigerant circulation pipe unit connected to the outdoor unit,
the at least one first indoor unit, and the at least one second
indoor unit to circulate a refrigerant, includes alternately
operating the at least one first indoor unit and the at least one
second indoor unit, upon judging that a simultaneous operating
condition of the at least one first indoor unit and the at least
one second indoor unit is satisfied.
[0023] Any one of the at least one first indoor unit and the at
least two indoor unit may be preferentially operated, upon judging
that the simultaneous operating condition of the at least one first
indoor unit and the at least one second indoor unit is satisfied.
Here, the at least one first indoor unit may be preferentially
operated.
[0024] In accordance with another aspect, a heat pump system
includes at least one first indoor unit including an indoor air
heat exchanger and a first expander, at least one second indoor
unit including an indoor water-refrigerant heat exchanger and a
second expander, an outdoor unit including an outdoor air heat
exchanger, a compressor, and a third expander, a refrigerant
circulation pipe unit connected to the at least one first indoor
unit, the at least one second indoor unit, and the outdoor unit to
circulate a refrigerant, a refrigerant distribution unit to
circulate the refrigerant selectively to the at least one first
indoor unit and the at least one second indoor unit, and a control
unit controlling the at least one first indoor unit and the at
least one second indoor unit so as to be alternately operated, upon
judging that a simultaneous operating condition of the at least one
first indoor unit and the at least one second indoor unit is
satisfied.
[0025] The refrigerant distribution unit may include a four-way
valve and check valves, or may include a three-way valve.
[0026] The control unit may execute a preliminary heating operation
by driving the compressor, under the condition that the expander of
one of the at least one first indoor unit and the at least one
second indoor unit, a heating operation of which is executed, is
closed and the expander of the other one of the at least one first
indoor unit and the at least one second indoor unit is opened,
before the heating operation of the one of the at least one first
indoor unit and the at least one second indoor unit is
executed.
[0027] In accordance with a further aspect, a control method of a
heat pump system, which has at least one first indoor unit
including an indoor air heat exchanger and a first expander, at
least one second indoor unit including an indoor water-refrigerant
heat exchanger and a second expander, an outdoor unit including an
outdoor air heat exchanger, a compressor, and a third expander, a
refrigerant circulation pipe unit connected to the at least one
first indoor unit, the at least one second indoor unit, and the
outdoor unit to circulate a refrigerant, and a refrigerant
distribution unit to circulate the refrigerant selectively to the
at least one first indoor unit and the at least one second indoor
unit, includes executing a preliminary heating operation by driving
the compressor, under the condition that the expander of one of the
at least one first indoor unit and the at least one second indoor
unit, a heating operation of which is executed, is closed and the
expander of the other one of the at least one first indoor unit and
the at least one second indoor unit is opened, before the heating
operation of the one of the at least one first indoor unit and the
at least one second indoor unit is executed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] These and/or other aspects will become apparent and more
readily appreciated from the following description of the
embodiments, taken in conjunction with the accompanying drawings of
which:
[0029] FIG. 1 is a schematic view illustrating the overall
configuration of a heat pump system in accordance with one
embodiment;
[0030] FIG. 2 is a schematic view illustrating the overall
configuration of a heat pump system in accordance with another
embodiment;
[0031] FIG. 3 is a first detailed view of the heat pump system of
FIG. 1;
[0032] FIG. 4 is a second detailed view of the heat pump system of
FIG. 1;
[0033] FIG. 5 is a detailed view of the heat pump system of FIG.
2;
[0034] FIG. 6 is a block diagram illustrating an operation of a
control unit of a heat pump system in accordance with one
embodiment;
[0035] FIG. 7 is a detailed view illustrating a first preliminary
heating operation of the heat pump system in accordance with the
embodiment;
[0036] FIG. 8 is a detailed view illustrating a first heating
operation of the heat pump system in accordance with the
embodiment;
[0037] FIG. 9 is a detailed view illustrating a second preliminary
heating operation of the heat pump system in accordance with the
embodiment;
[0038] FIG. 10 is a detailed view illustrating a second heating
operation of the heat pump system in accordance with the
embodiment;
[0039] FIG. 11 is a detailed view illustrating a first cooling
operation of the heat pump system in accordance with the
embodiment;
[0040] FIG. 12 is a detailed view illustrating a second cooling
operation of the heat pump system in accordance with the
embodiment;
[0041] FIG. 13 is a detailed view illustrating a second heating
operation of the heat pump system in accordance with the embodiment
using a sub heater;
[0042] FIG. 14 is a flow chart illustrating a time division
multiplexing (TDM) alternating operation of the heat pump system in
accordance with the embodiment;
[0043] FIG. 15 is a flow chart illustrating preferential execution
of one operation during the TDM alternating operation of FIG.
14;
[0044] FIG. 16 is a flow chart illustrating a control method of the
heat pump system, if set temperatures of a first indoor unit and a
second indoor unit are equal;
[0045] FIG. 17 is a flow chart illustrating preferential execution
of the hot water operation;
[0046] FIG. 18 is a flow chart illustrating a simultaneous
operation of heat pumps in accordance with one embodiment; and
[0047] FIG. 19 is a graph illustrating input and output flows
illustrating an alternating operation of the heat pumps in
accordance with the embodiment.
DETAILED DESCRIPTION
[0048] Reference will now be made in detail to the embodiments,
examples of which are illustrated in the accompanying drawings,
wherein like reference numerals refer to like elements
throughout.
[0049] FIG. 1 is a schematic view illustrating the overall
configuration of a heat pump system in accordance with one
embodiment.
[0050] A heat pump system 1 in accordance with this embodiment
includes an outdoor unit 10, a refrigerant distribution unit 20, a
first indoor unit 30, a second indoor unit 40, a heating load 50,
and a hot water tank 60. The heat pump system 1 further includes a
refrigerant circulation pipe unit 11 formed in a closed loop via
the outdoor unit 10, the refrigerant distribution unit 20, the
first indoor unit 30, and the second indoor unit 40.
[0051] The refrigerant circulation pipe unit 11 includes
refrigerant circulation pipes 11a and 11b connecting the outdoor
unit 10 and the refrigerant distribution unit 20, a refrigerant
circulation pipe 11c connecting the refrigerant distribution unit
20 and the first indoor unit 30, and refrigerant circulation pipes
11d and 11e connecting the second indoor unit 40 and the
refrigerant distribution unit 20.
[0052] Further, a water circulation pipe unit 17 is connected to
the second indoor unit 40, and is connected to the heating load 50
and the hot water tank 60. The water circulation pipe unit 17 is
also formed in a closed loop. A detailed structure of the water
circulation pipe unit 17 will be described later.
[0053] FIG. 2 is a schematic view illustrating the overall
configuration of a heat pump system in accordance with another
embodiment.
[0054] In FIG. 2, a heat pump system 2 in accordance with this
embodiment includes an outdoor unit 12 having five connection
pipes, and the refrigerant distribution unit 20 and the second
indoor unit 40 of FIG. 1 are installed within the outdoor unit 12.
Other structures of FIG. 2 are the same as those of FIG. 1, and a
detailed description thereof will thus be omitted.
[0055] FIG. 3 is a first detailed view of the heat pump system of
FIG. 1. With reference to FIG. 3, the structure and operation of
the heat pump system 1 in accordance with one embodiment will be
described in detail.
[0056] The outdoor 10 includes a compressor 14, a first four-way
valve 15, a third expander 16, a third heat exchanger 18, and two
connection valves 13a and 13b.
[0057] The compressor 14 serves to compress a refrigerant from a
low-temperature and low-pressure gaseous state to a
high-temperature and high-pressure gaseous state, and may include a
variable capacity compressor having a compression capacity which is
variable according to the loads 30 and 40.
[0058] Further, the compressor 14 may include an inverter
compressor having a compression capacity which is variable
according to input frequencies, or a combination of a plurality of
constant speed compressors, each of which has a constant
compression capacity. The compressor 14 is connected to the first
four-way valve 15 through the refrigerant circulation pipe unit
11.
[0059] The first four-way valve 15 is a valve which may be opened
and closed in four directions, and serves to guide the refrigerant
having passed through the refrigerant circulation pipe unit 11 in
two directions. As shown in FIG. 3, the refrigerant having passed
through the compressor 14 is transmitted to the refrigerant
distribution unit 20 or the third heat exchanger 18 through the
refrigerant circulation pipe unit 11.
[0060] The expander 16 is a kind of a variable expansion device,
which expands or intercepts the refrigerant having passed through
the third heat exchanger 18 or the load 30 or 40, and includes an
electronic expansion valve (EEV), an opening value of which is
variable, so as to adjust an amount of the refrigerant. The
expander 16 is connected to the loads 30 and 40 and the third heat
exchanger 18 through the refrigerant circulation pipe unit 11.
[0061] The third heat exchanger 18 is a kind of the above-stated
A2A heat exchanger, and serves to exchange heat between the
refrigerant having passed through the compressor 14 or the expander
16 and outdoor air. The third heat exchanger 18 may include a fan
(not shown) to exchange heat between the refrigerant and outdoor
air.
[0062] The connection valves 13a and 13b serve to connect the
refrigerant circulation pipes 11a and 11b, connecting the outdoor
unit 10 and the refrigerant distribution unit 20, to the outdoor
unit 10.
[0063] The refrigerant distribution unit 20 includes a second
four-way valve 22, three check valves 23, 24, and 25, a capillary
tube 26, and connection valves 13d-13h.
[0064] The second four way valve 22 is opened and closed so as to
circulate the refrigerant passing through the refrigerant
circulation pipe unit 11 selectively toward the first indoor unit
30 and the second indoor unit 40. That is, if it is desired that
the refrigerant be circulated toward the first indoor unit 30,
although this is not shown in FIG. 3, a first valve 22a and a
second valve 22b are communicated with each other to circulate the
refrigerant toward the first indoor unit 30, and a third valve 22c
and a fourth valve 22d are communicated with each other. On the
other hand, if it is desired that the refrigerant be circulated
toward the second indoor unit 40, the first valve 22a and the
fourth valve 22d are communicated with each other, and the second
valve 22b and the third valve 22c are communicated with each other.
Detailed operations of respective cooling and heating cycles will
be described later.
[0065] The three check valves 23, 24, and 25 serve to enable the
refrigerant to flow only in one direction, and the capillary tube
26 serves to expand the refrigerant.
[0066] The first indoor unit 30 is a heat pump to cool or heat
indoor air, and includes a first heat exchanger 32 which is a kind
of an A2A heat exchanger, i.e., outdoor air heat exchanger, a first
expander 34, and a connection valve 13i. The first heat exchanger
32 exchanges heat between the cold or hot refrigerant passing
through the refrigerant circulation pipe unit 11 and air, thus
cooling or heating indoor air. The first expander 34 executes the
same role as the third expander 18.
[0067] The second indoor unit 40 is a heat pump to cool or heat
water in the water circulation pipe unit 17, and includes a second
heat exchanger 42 which is a kind of an A2W heat exchanger, i.e.,
water-refrigerant heat exchanger, a second expander 44, and a
connection valve 13j. The second heat exchanger 42 exchanges heat
between the cold or hot refrigerant passing through the refrigerant
circulation pipe unit 11 and the water in the water circulation
pipe unit 17, thus cooling or heating the water in the water
circulation pipe unit 17. The second expander 44 executes the same
role as the third expander 18.
[0068] The water circulation pipe unit 17, through which water
heated or cooled through the second heat exchanger 42 is
circulated, is again connected to the heating load 50 and the hot
water tank 60. The heating load 50 includes a fourth heat exchanger
52 to exchange heat between the water in the water circulation pipe
unit 17 and air, and the hot water tank 60 includes a fifth heat
exchanger 62 to exchange heat between the water in the water
circulation pipe unit 17 and the water stored in the hot water tank
60. Further, a three-way valve (not shown) is installed at a point
where the water circulation pipe unit 17 is branched off into the
heating load 50 and the hot water tank 60, and is opened and closed
toward a desired load under the control of a control unit 45 which
will be described later.
[0069] FIG. 4 is a second detailed view of the heat pump system of
FIG. 1. The heat pump system 1 of FIG. 4 has the same structure as
that of the heat pump system 1 of FIG. 3 except that a three-way
valve 21 is installed in a refrigerant distribution unit 20'
instead of the second four way valve 22. If the three-way valve 21
is used, when the first indoor unit 30 and the second indoor unit
40 are alternately operated, circulation of the refrigerant toward
the refrigerant circulation pipe unit 11 at the indoor unit which
is not operated is blocked.
[0070] FIG. 5 is a detailed view of the heat pump system of FIG. 2.
As described above, the heat pump system 2 includes the outdoor
unit 12 having the five connection pipes, 13a, 13b, 13k, 13l, and
13m, and the refrigerant distribution unit 20 and the second indoor
unit 40 are installed within the outdoor unit 12. That is, the
outdoor unit 12 of FIG. 5 is the integral outdoor unit 12 in which
the second indoor unit 40, i.e., a hydro unit, is installed. The
heat pump system 2 has a structure which is slightly different from
that of the heat pump system 1, and thus the heat pump system 1 is
exemplarily described hereinafter.
[0071] FIG. 6 is a block diagram illustrating an operation of a
control unit of a heat pump system in accordance with one
embodiment.
[0072] The heat pump system 1 includes a control unit 45 and an
input unit 46. The input unit 46 may be a device, such as a remote
controller, or may be installed integrally with the control unit
45. The input unit 46 enables a user to input an operation mode or
a set temperature of the heat pump system 1.
[0073] The control unit 45 controls the first four-way valve 15,
the second four-way valve 22, the first expander 34, the second
expander 44, and the third expander 16 according to data input
through the input unit 46. Although the control unit 45 may be
installed in the outdoor unit 10, the control unit 45 is generally
installed in the first indoor unit 30 or the second indoor unit 40
close to the user. Here, heating and cooling operation cycles of
the heat pump system 1 based on the operation of the control unit
45 will be described in detail.
[0074] FIG. 7 is a detailed view illustrating a first preliminary
heating operation of the heat pump system in accordance with the
embodiment.
[0075] The heat pump system 1 in accordance with this embodiment is
controlled such that the first indoor unit 30 and the second indoor
unit 40 are alternately operated using a time division multiplexing
(TDM) method, which will be described with reference to FIGS. 14 to
19. Such an alternating operation will be described in detail with
reference to FIGS. 14 to 19, and a preliminary heating operation to
prevent shortage of an amount of the refrigerant during the heating
operation due to trapping of the refrigerant within a stopped
indoor unit, if the first indoor unit 30 or the second indoor unit
40 executes the heating operation, will be described in detail
now.
[0076] Here, "the preliminary heating operation" means a
refrigerant recovery operation in which the refrigerant trapped in
the stopped indoor unit is recovered before the heating operation.
With reference to FIG. 7, the first preliminary heating operation,
i.e., a preliminary heating operation of the indoor unit 30, will
be described.
[0077] Although this will be described later, the time division
multiplexing (TDM) method is a method in which, if the first indoor
unit 30 and the second indoor unit 40 are operated, the first
indoor unit 30 and the second indoor unit 40 are alternately
operated. Therefore, as shown in a refrigerant cycle circuit shown
in FIG. 7, when the first valve 22a and the second valve 22b of the
second four-way valve 22 are communicated with each other and the
third valve 22c and the fourth valve 22d of the second four-way
valve 22 are communicated with each other, and then the compressor
14 is driven under the condition that the first expander 34 is
opened and the second expander 44 is closed, the refrigerant is
accumulated and trapped in a oval second region 38 shown in a
dotted line. This happens because the second expander 44 is closed
and thus the refrigerant does not move to the right side of the
expander 44, and the refrigerant does not move through the
refrigerant circulation pipe unit 11 where the check valve 24 is
located due to the pressure of the refrigerant discharged from the
compressor 14.
[0078] Therefore, the trapping of the refrigerant may generate
shortage of the amount of the refrigerant during the heating
operation. In order to reduce the trapping of the refrigerant, the
second expander 44 is not completely closed, but is opened at more
than a designated opening value. However, although the second
expander 44 is opened at more than the designated opening value,
the indoor unit 30 may not have 100% output, and thus in case of an
operation requiring 100% output, problems are generated.
[0079] Therefore, in order to remove the trapping of the
refrigerant, the preliminary heating operation which is the
refrigerant recovery operation to completely recover the trapped
refrigerant is executed. FIG. 7 illustrates a flow of the
refrigerant, if the first preliminary heating operation of the
first indoor unit 30 is executed before the heating operation.
[0080] During the first preliminary heating operation of the first
indoor unit 30, the first valve 22a and the second valve 22b of the
second four-way valve 22 are communicated with each other and the
third valve 22c and the fourth valve 22d of the second four-way
valve 22 are communicated with each other, and then the compressor
14 is driven under the condition that the first expander 34 is
closed and the second expander 44 is opened.
[0081] When the compressor 14 is driven, the refrigerant trapped in
the second region 38 sequentially passes through the refrigerant
circulation pipe 11e, the refrigerant circulation pipe 11b, the
expander 16, the third heat exchanger 18, the compressor 14, and
the second four-way valve 22 due to the pressure of the compressor
14, and then is accumulated in a first region 36. That is, since
the first expander 34 is closed, all of the refrigerant in the
refrigerant circulation pipe unit 11 is temporarily accumulated in
the first region 36, and all of the refrigerant accumulated in the
second region 38 is collected in the first region 36. A heating
operation is executed after such a refrigerant recovery operation,
and a detailed description thereof will be given with reference to
FIG. 8.
[0082] FIG. 8 is a detailed view illustrating a first heating
operation of the heat pump system in accordance with the
embodiment.
[0083] When all of the refrigerant trapped in the second region 38
is recovered in the first region 36 by the first preliminary
heating operation of FIG. 7, the control unit 45 opens the first
expander 34 and closes the second expander 44 and thus executes the
heating operation of the first indoor unit 30. At this time, since
none of the refrigerant is trapped in the second region 38 and the
circulated refrigerant is not introduced into the second region 38
by the check valve 24 and the second expander 44, the heating
operation of the first indoor unit 30 may be executed at 100%
output. Since the heating operation is executed, the refrigerant in
a high-temperature and high-pressure state generated from the
compressor 14 exchanges heat with air through the first heat
exchanger 32 via the first four-way valve 15 and the second
four-way valve 22, thus being changed into a low-temperature and
high-pressure state. The refrigerant in the low-temperature and
high-pressure state is changed into a low-temperature and
low-pressure state through the first expander 34, the third
expander 16, and the third heat exchanger 18, and then is again
introduced into the compressor 14. The heating operation of the
first indoor unit 30 is executed through such a cycle.
[0084] FIG. 9 is a detailed view illustrating a second preliminary
heating operation of the heat pump system in accordance with the
embodiment, and FIG. 10 is a detailed view illustrating a second
heating operation of the heat pump system in accordance with the
embodiment.
[0085] FIGS. 9 and 10 respectively illustrate flows of the
refrigerant during the second preliminary heating operation and the
heating operation of the second indoor unit 40. In the second
preliminary heating operation and the heating operation of the
second indoor unit 40, the communication direction of the second
four-way valve 22 and the control direction of the first expander
34 and control of the second expander 44 are changed so as to be
opposite to the directions in the first preliminary heating
operation and the heating operation of the first indoor unit 30,
and a detailed description thereof will thus be omitted.
[0086] FIG. 11 is a detailed view illustrating a first cooling
operation of the heat pump system in accordance with the
embodiment, and FIG. 12 is a detailed view illustrating a second
cooling operation of the heat pump system in accordance with the
embodiment.
[0087] As shown in FIGS. 11 and 12, a preliminary cooling operation
is not executed before a cooling operation. During the cooling
operation, the compressor 14 discharges the refrigerant in the
direction opposite to the discharging direction of the refrigerant
from the compressor 14 during the heating operation., Then, the
compressor 14 is in a low-pressure state due to refrigerant suction
force, and thus the refrigerant naturally moves to the compressor
14 through the refrigerant circulation pipe unit 11 where the check
valve 24 is located. That is, the refrigerant is circulated through
the refrigerant circulation pipe unit 11.
[0088] As described above, the refrigerant in the high-temperature
and high-pressure state generated from the compressor 14 without
the refrigerant recovery operation is changed to a low-temperature
and high-pressure state through the third heat exchanger 18, is
changed to a low-temperature and low-pressure state through the
third expander 16 and the first expander 34, and then exchanges
heat with air through the first heat exchanger 32 and thus is
changed to a high-temperature and low-pressure state.
[0089] FIG. 12 illustrates the cooling operation of the second
indoor unit 40, i.e., the second cooling operation. The second
cooling operation of the second indoor unit 40 shown in FIG. 12
differs from the first cooling operation of the first indoor unit
30 shown in FIG. 11 only in that the second four-way valve 22, and
the valves of the first expander 34 and the second expander 44
during the second cooling operation of the second indoor unit 40
are operated in directions opposite to the directions during the
first cooling operation of the first indoor unit 30, and a detailed
description thereof will thus be omitted.
[0090] FIG. 13 is a detailed view illustrating a second heating
operation of the heat pump system in accordance with the embodiment
using a sub heater.
[0091] FIG. 13 illustrates that the heat pump system shown in FIG.
8 further includes a first sub heater 43 installed at the water
circulation pipe unit 17 of the second heat exchanger 42 of the
second indoor unit 40 and a second sub heater 64 installed in the
hot water tank 60.
[0092] During the heating operation of FIG. 13, at least one of the
first sub heater 43 and the second sub heater 64 is operated if an
output of the outdoor unit 10 is smaller than an output required
during the heating operation due to a problem, such as a hot water
operation of the hot water tank 60.
[0093] Further, although this is not shown in FIG. 13, if a hot
water operation mode of the hot water tank 60 is input through the
input unit 46 during the cooling operation of the first indoor unit
30 under the condition that the first valve 22a and the second
valve 22b of the second four-way valve 22 are communicated with
each other and the third valve 22c and the fourth valve 22d of the
second four-way valve 22 are communicated with each other, the hot
water operation of the hot water tank 60 may be executed using at
least one of the first sub heater 43 and the second sub heater 64
while continuously executing the cooling operation of the first
indoor unit 30 using the outdoor unit 10.
[0094] Hereinafter, a method of controlling an alternating
operation of the first indoor unit 30 and the second indoor unit 40
through the TDM method using the heat pump system 1 having the
above-described structure will be described in detail.
[0095] FIG. 14 is a flow chart illustrating a time division
multiplexing (TDM) alternating operation of the heat pump system in
accordance with the embodiment, and FIG. 15 is a flow chart
illustrating preferential execution of one operation during the TDM
alternating operation of FIG. 14.
[0096] In the heat pump system 1 in accordance with one embodiment,
if it is judged that an operating condition of any one of the first
indoor unit 30 and the second indoor unit 40 is satisfied, the
first indoor unit 30 or the second indoor unit 40 is operated at
100% output. Here, a capacity of the first indoor unit 30 and a
capacity of the second indoor unit 40 are equal to that of the
outdoor unit 10. Further, the sum total of the capacity of the
first indoor unit 30 and the capacity of the second indoor unit 40
may be in the range of 50-130% of the capacity of the outdoor unit
10 according to design specifications. Further, the first indoor
unit 30 and the second indoor unit 40 may have various
capacities.
[0097] As shown in FIG. 14, it is judged whether or not a
simultaneous operating condition of the first indoor unit 30 and
the second indoor unit 40 is satisfied (operation 100), and the
first indoor unit 30 and the second indoor unit 40 are alternately
operated through the TDM method if it is judged that the
simultaneous operating condition of the first indoor unit 30 and
the second indoor unit 40 is satisfied (operation 102). This will
be described in detail with reference to FIG. 15.
[0098] FIG. 15 illustrates preferential execution of the operation
of the first indoor unit 30 during the alternating operation of the
first indoor unit 30 and the second indoor unit 40. The reason for
the preferential execution of the operation of the first indoor
unit 30 is as follows.
[0099] That is, if a load requirement is given by a user under the
condition that heat accumulation of a load is low, as in a house,
the first indoor unit 30 rapidly reaching performance is
preferentially operated so as to satisfy the user, and then the
second indoor unit 30 slowly reaching performance is alternately
operated, thereby changing the operation of the heat pump system
from convective cooling or heating to radiant cooling or
heating.
[0100] With reference to FIG. 15, the control unit 45 judges
whether or not a simultaneous operating condition of the first
indoor unit 30 and the second indoor unit 40 is satisfied
(operation 104). If it is judged that the simultaneous operating
condition of the first indoor unit 30 and the second indoor unit 40
is satisfied, the control unit 45 operates the first indoor unit
(operation 106). The control unit 45 judges whether or not an
operation completing condition of the first indoor unit 30 is
satisfied during the cooling or heating operation of the first
indoor unit 30 (operation 108). The control unit 45 continuously
executes the operation of the first indoor unit 30, if it is judged
that the operation completing condition of the first indoor unit 30
is not satisfied, and stops the operation of the first indoor unit
30 and operates the second indoor unit 40, if it is judged that the
operation completing condition of the first indoor unit 30 is
satisfied (operation 110).
[0101] Here, the operation completing condition of the first indoor
unit 30 may include whether or not the first indoor unit 30 reaches
a first target temperature, i.e., a target set temperature of the
first indoor unit 30, or whether or not the first indoor unit 30 is
operated for a first set time, i.e., the minimum or maximum
operating time of the first indoor unit 30.
[0102] The control unit 45 judges whether or not an operation
completing condition of the second indoor unit 40 is satisfied
during the operation of the second indoor unit 40 (operation 114).
The control unit 45 continuously executes the operation of the
second indoor unit 40, if it is judged that the operation
completing condition of the second indoor unit 40 is not satisfied,
and stops the operation of the second indoor unit 40, if it is
judged that the operation completing condition of the second indoor
unit 40 is satisfied (operation 116).
[0103] The operation completing condition of the second indoor unit
40 may also include whether or not the second indoor unit 40
reaches a second target temperature, i.e., a target set temperature
of the second indoor unit 40, or whether or not the second indoor
unit 40 is operated for a second set time i.e., the minimum or
maximum operating time of the second indoor unit 40.
[0104] Here, the reason why the first set time and the second set
time, i.e., the minimum or maximum operating times, are used as the
operation completing conditions of the first and second indoor
units 30 and 40 is to prevent frequent operation change between the
first indoor unit 30 and the second indoor unit 40 and to prevent
failure to satisfy the load of the second indoor unit 2.
[0105] If it is judged that the simultaneous operating condition of
the first indoor unit 30 and the second indoor unit 40 is not
satisfied, the control unit 45 judges whether or not an operating
condition of any one of the first indoor unit 30 and the second
indoor unit 40 is satisfied (operation 118). If it is judged that
an operating condition of any one of the first indoor unit 30 and
the second indoor unit 40 is satisfied, the control unit 45
operates the first indoor unit 30 or the second indoor unit 40
(operation 120).
[0106] The control unit 45 judges whether or not the operation
completing condition of the first indoor unit 30 or the second
indoor unit 40 is satisfied during the operation of the first
indoor unit 30 or the second indoor unit 40 (operation 122). The
control unit 45 continuously executes the operation of the first
indoor unit 30 or the second indoor unit 40, if it is judged that
the operation completing condition of the first indoor unit 30 or
the second indoor unit 40 is not satisfied, and stops the operation
of the first indoor unit 30 or the second indoor unit 40, if it is
judged that the operation completing condition of the first indoor
unit 30 or the second indoor unit 40 is satisfied (operation
124).
[0107] The operation completing condition of the first indoor unit
30 or the second indoor unit 40 may include whether or not the
first indoor unit 30 or the second indoor unit 40 reaches the first
target temperature or the second target temperature, or whether or
not the hot water operation mode is input, which will be described
later.
[0108] FIG. 16 is a flow chart illustrating a control method of the
heat pump system, if set temperatures of the first indoor unit and
the second indoor unit are equal.
[0109] That is, as shown in 15, if it is judged that the
simultaneous operating condition of the first indoor unit 30 and
the second indoor unit 40 is satisfied, the first indoor unit 30
and the second indoor unit 40 are alternately operated through the
TDM method. However, when target set temperatures of the first
indoor unit 30 and the second indoor unit 40 input through the
input unit 46 are equal, if the operation completing condition of
the first indoor unit 30 is satisfied, the operation completing
condition of the second indoor unit 40 is also satisfied, and thus
the second indoor unit 40 is not operated and is stopped. In this
case, only the first indoor unit 30 is continuously switched on and
off, and the stoppage of the second indoor unit 40 is maintained.
If the above state is continued, the target set temperature of the
first indoor unit 30 is forcibly lowered by 1 to 2.degree. C., and
thereby the second indoor unit 40 is operated. FIG. 16 illustrates
such a method.
[0110] That is, if the simultaneous operating condition of the
first indoor unit 30 and the second indoor unit 40 is satisfied and
thus the first indoor unit is preferentially operated and then the
operation completing condition of the first indoor unit 30 is
satisfied and thus the operation of the first indoor unit 30 is
stopped (operation 110), as shown in FIG. 15, the control unit 45
judges whether or not the target set temperatures of the first
indoor unit 30 and the second indoor unit 40 are equal (operation
126). Here, if it is judged that the target set temperatures of the
first indoor unit 30 and the second indoor unit 40 are not equal,
the process is returned to operation 112 of FIG. 15 and then the
operation of the first indoor unit 40 is restarted.
[0111] On the other hand, if it is judged that the target set
temperatures of the first indoor unit 30 and the second indoor unit
40 are equal, the target set temperature of the first indoor unit
30 is lowered by a designated value (operation 128). Thereby, the
operating condition of the second indoor unit 40 is satisfied under
the condition that the operation completing condition of the first
indoor unit 30 is satisfied, and thus the second indoor unit 40 is
operated.
[0112] FIG. 17 is a flow chart illustrating preferential execution
of the hot water operation.
[0113] The heat pump system 1 in accordance with one embodiment
executes the TDM alternating operation, if it is judged that the
simultaneous operating condition of the first indoor unit 30 and
the second indoor unit is satisfied. However, if a temporary
excessive hot water requirement is input, the heat pump system 1
may ignore the TDM alternating operation and preferentially execute
the hot water operation. With reference to FIG. 17, the
preferential execution of the hot water operation will be described
as follows.
[0114] The control unit 45 judges whether or not a hot water
operation mode is input (operation 130). If it is judged that the
hot water operation mode is input, the control unit 45 judges
whether or not a hot water set temperature is more than a critical
temperature (operation 132). Only if it is judged that the hot
water set temperature is more than the critical temperature, the
hot water operation is preferentially executed so as to prevent
unnecessary mode change.
[0115] If it is judged that the hot water set temperature is more
than the critical temperature, the control unit 45 stops the TDM
alternating operation, and preferentially executes the hot water
operation (operation 134). The control unit 45 judges whether or
not the heat pump system 1 reaches the hot water set temperature
during the hot water operation (operation 136).
[0116] The control unit 45 continuously executes the hot water
operation, if it is judged that the heat pump system 1 does not
reach the hot water set temperature, and stops the hot water
operation, if it is judged that the heat pump system 1 reaches the
hot water set temperature (operation 138).
[0117] The preferential execution of the hot water operation may be
carried out only during the TDM alternating operation, or may be
also carried out during the individual operation of the first
indoor unit 30 or the second indoor unit 40.
[0118] FIG. 18 is a flow chart illustrating a simultaneous
operation of heat pumps in accordance with one embodiment.
[0119] The heat pump system 1 in accordance with one embodiment of
the present invention basically executes the TDM alternating
operation, if it is judged that the simultaneous operating
condition of the first indoor unit 30 and the second indoor unit is
satisfied. However, if the sum total of capacities required by the
first indoor unit 30 and the second indoor unit 40 is less than the
maximum capacity suppliable by the outdoor unit 10 due to a
required capacity of a load, the heat pump system 1 may
simultaneously operate the first indoor unit 30 and the second
indoor unit 40.
[0120] That is, the control unit 45 judges whether or not the sum
total of capacities required by the first indoor unit 30 and the
second indoor unit 40 is less than the maximum capacity of the
outdoor unit 10 (operation 140). If it is judged that the sum total
of capacities required by the first indoor unit 30 and the second
indoor unit 40 is more than the maximum capacity of the outdoor
unit 10, the control unit 45 executes the TDM alternating operation
(operation 144).
[0121] However, if it is judged that the sum total of capacities
required by the first indoor unit 30 and the second indoor unit 40
is less than the maximum capacity of the outdoor unit 10, the
control unit 45 simultaneously operates the first indoor unit 30
and the second indoor unit (operation 142).
[0122] FIG. 19 is a graph of input and output flows illustrating an
alternating operation of the heat pumps in accordance with the
embodiment.
[0123] Hereinafter, an operation of the first indoor unit 30 and an
operation of the second indoor unit 40 based on a signal requesting
the operation of the first indoor unit 30 and a signal requesting
the operation of the second indoor unit 40 of FIG. 19 will be
described.
[0124] In a section (a), the signal requesting the operation of the
second indoor unit 40 is input, and thus the second indoor unit 40
is operated. During the operation of the second indoor unit 40, in
a section (b), the signal requesting the operation of the first
indoor unit 30 is input, and thus the simultaneous operating
condition of the first indoor unit 30 and the second indoor unit 40
is satisfied. However, since the first indoor unit 30 needs to be
preferentially operated, the first indoor unit 30 is operated and
the operation of the second indoor unit 40 is stopped.
[0125] Although the simultaneous operating condition of the first
indoor unit 30 and the second indoor unit 40 is the same even when
the heat pump system enters a section (c) after the section (b),
since the maximum operating time of the first indoor unit 30 is set
to a time corresponding to the length of the section (b), the
operation of the first indoor unit 30 is stopped at the moment when
the heat pump system enters the section (c), and then the second
indoor unit 40 is operated.
[0126] Although the simultaneous operating condition of the first
indoor unit 30 and the second indoor unit 40 is the same even when
the heat pump system enters a section (d) after the section (c),
since the maximum operating time of the second indoor unit 40 is
set to a time corresponding to the length of the section (c), the
operation of the second indoor unit 40 is stopped at the moment
when the heat pump system enters the section (d), and then the
first indoor unit 30 is operated.
[0127] When the heat pump system enters a section (e) after the
section (d), the signal requesting the operation of the first
indoor unit 30 disappears, and thus the operation of the first
indoor unit 30 is stopped and the second indoor unit 40 is
operated.
[0128] When the heat pump system enters a section (f) after the
section (e), the simultaneous operating condition of the first
indoor unit 30 and the second indoor unit 40 is satisfied again and
the operation of the first indoor unit 30 is preferred, and thus
the first indoor unit 30 is operated and the operation of the
second indoor unit 40 is stopped.
[0129] Next sections are carried out by the above-described method,
and a detailed description thereof will thus be omitted.
[0130] Further, although this is not shown in the drawings, if the
compressor 14 of the outdoor unit 10 is a variable capacity
compressor having a compression capacity which is variable, such as
an inverter, an output of the outdoor unit 10 is automatically
adjusted due to a difference between a set temperature and a
current temperature. However, in order to smoothly execute the
operation through the TDM method, the control unit 45 ignores the
automatic output control, and operates the outdoor unit 10
according the maximum capacity of the operating indoor unit 30 or
40, thereby rapidly executing the heating or cooling operation.
[0131] Further, the TDM operation may be executed under the
condition that a specific one or plural input units among a remote
controller input unit (not shown) and the input unit 46, such as a
separate thermostat of the heat pump system 1, are designated, and
the operations of the first indoor unit 30 and the second indoor
unit 40 are limited to the heating or cooling operation according
to heating/cooling mode change input through the designated input
unit(s). Thereby, the compressor 14 may not be stopped/re-operated
during the TDM alternating operation of the first indoor unit 30
and the second indoor unit 40, thus reducing an operation stopping
time and facilitating improvement of life span and reliability of
the compressor.
[0132] Through the above method, if it is judged that the
simultaneous operating condition of the first indoor unit 30 and
the second indoor unit 40 is satisfied, the heat pump system 1 in
accordance with one embodiment of the present invention basically
executes the TDM alternating operation. However, if one of other
set conditions is satisfied, the heat pump system 1 preferentially
executes the hot water operation or executes the simultaneous
operation of the first indoor unit 30 and the second indoor unit
40, thereby being capable of driving multiple loads at the maximum
output without any additional unit. Further, when the first indoor
unit 30 and the second indoor unit 40 are simultaneously operated,
sensory cooling or heating dissatisfaction generated due to a
specific heat difference between air and water may be reduced.
[0133] As is apparent from the above description, in a heat pump
system and a control method thereof in accordance with one
embodiment, cooling and heating operations of an A2A indoor unit
and cooling and heating operations and a hot water operation of an
A2W indoor unit are effectively executed through a time division
multiplexing (TDM) method without installation of any additional
unit or increase of a capacity of an outdoor unit.
[0134] Further, a refrigerant distribution unit is installed and a
preliminary heating operation is executed, thereby preventing
shortage of a refrigerant during the heating operation when the
indoor units are alternately operated through the TDM method.
[0135] Although a few embodiments have been shown and described, it
would be appreciated by those skilled in the art that changes may
be made in these embodiments without departing from the principles
and spirit of the invention, the scope of which is defined in the
claims and their equivalents.
* * * * *