U.S. patent application number 13/120321 was filed with the patent office on 2011-07-14 for air-conditioning refrigerating system.
This patent application is currently assigned to SANYO ELECTRIC CO., LTD.. Invention is credited to Tsuyoshi Kawaai.
Application Number | 20110167852 13/120321 |
Document ID | / |
Family ID | 42059483 |
Filed Date | 2011-07-14 |
United States Patent
Application |
20110167852 |
Kind Code |
A1 |
Kawaai; Tsuyoshi |
July 14, 2011 |
AIR-CONDITIONING REFRIGERATING SYSTEM
Abstract
An air-conditioning refrigerating system that enables demand
control based on operation control of an air-conditioning system
and a refrigerating system is provided. The air-conditioning
refrigerating system 1 is constructed to have an air-conditioning
system 10 in which plural indoor units 34 are connected to an
outdoor unit 32 to air-condition a building, a refrigerating system
12 in which plural low-temperature showcases 7 are connected to a
rack system refrigerating machine 3 to cool each of the
low-temperature showcases 7, a main controller 4 for generating and
outputting air-conditioning demand data for varying power
consumption of the refrigerating system and refrigerating demand
data for varying power consumption of the refrigerating system 12
on the basis of commercial power consumption of the building, and
an external controller 14 that is provided separately from the
refrigerating system 12, receives the refrigerating demand data
from the main controller 4 and controls the operation of the rack
system refrigerating machine on the basis of the refrigerating
demand data.
Inventors: |
Kawaai; Tsuyoshi; (Uji-shi,
JP) |
Assignee: |
SANYO ELECTRIC CO., LTD.
Moriguchi-shi, Osaka
JP
|
Family ID: |
42059483 |
Appl. No.: |
13/120321 |
Filed: |
September 25, 2009 |
PCT Filed: |
September 25, 2009 |
PCT NO: |
PCT/JP2009/004846 |
371 Date: |
March 22, 2011 |
Current U.S.
Class: |
62/228.1 ;
62/190 |
Current CPC
Class: |
F25B 2700/1933 20130101;
F25B 49/02 20130101; F25B 2700/1931 20130101; F24F 11/30 20180101;
F25B 2400/075 20130101; F25B 2400/22 20130101; F25B 2700/172
20130101; F25B 2400/06 20130101; F24F 2140/60 20180101 |
Class at
Publication: |
62/228.1 ;
62/190 |
International
Class: |
F25B 49/02 20060101
F25B049/02; F25B 49/00 20060101 F25B049/00; A47F 3/04 20060101
A47F003/04 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 29, 2008 |
JP |
2008-250037 |
Claims
1. An air-conditioning refrigerating system characterized by
comprising: an air-conditioning system in which a plurality of
indoor units are connected to an outdoor unit through a refrigerant
pipe to air-condition the inside of a building; a refrigerating
system in which a plurality of showcases are connected to a
refrigerating machine through a refrigerant pipe to cool each of
the showcases; a main control device for generating and outputting
air-conditioning demand control data for controlling power
consumption of the air-conditioning system and refrigerating demand
control data for controlling power consumption of the refrigerating
system on the basis of consumed power; and an external control
device that is provided separately from the refrigerating system,
receives the refrigerating demand control data from the main
control device and controls an operation of the refrigerating
machine on the basis of the refrigerating demand control data.
2. The air-conditioning refrigerating system according to claim 1,
wherein the external control device is configured to acquire
control setting information required for control of a main element
for determining cooling capacity of the refrigerating machine, and
controls the main element of the refrigerating machine on the basis
of an operation state of the refrigerating machine and the control
setting information.
3. The air-conditioning refrigerating system according to claim 2,
wherein the external control device is configured to acquire, as
the control setting information, compressor control setting
information required for capacity control of a compressor installed
in the refrigerating machine, and controls a capacity of the
compressor on the basis of low-pressure side pressure of the
refrigerating machine and the compressor control setting
information.
4. The air-conditioning refrigerating system according to claim 3,
wherein the external control device is configured to acquire, as
the control setting information, condenser control setting
information required for condensation capacity control of a
condenser installed in the refrigerating machine, and controls a
condensation capacity of the condenser on the basis of a
high-pressure side pressure of the refrigerating machine and the
condenser control setting information.
5. The air-conditioning refrigerating system according to claim 4,
wherein the main control device controls the air-conditioning
system in priority to the refrigerating system on the basis of
power consumption.
6. The air-conditioning refrigerating system according to claim 4,
wherein when the power consumption of the refrigerating system is
controlled to be varied, the main control device controls the
condensation capacity of the condenser in priority to the capacity
of the compressor.
7. The air-conditioning refrigerating system according to any one
of claims 1 to 6, wherein the refrigerating machine is a
refrigerating machine that is freely constructed by arbitrarily
selecting main elements for determining a cooling capacity from
some types.
Description
TECHNICAL FIELD
[0001] The present invention relates to a technique for performing
demand control on the basis of commercial power consumed in
facilities such as a store or the like.
BACKGROUND ART
[0002] There has been known a refrigerating system in which plural
low-temperature showcases such as freezing/chilling showcases or
the like are connected to a refrigerating machine in parallel
through refrigerant pipes. Plural low-temperature cases as
described above are installed in a store such as a supermarket or
the like, and provided to display and sell foods while freezing or
chilling the foods. Furthermore, an air conditioning system for
performing an air-conditioning operation on the inside of the
store. In such a store, so-called demand control is performed to
integrate consumed commercial power every predetermined time and
reduce the commercial power consumption so that the integration
value does not exceed a predetermined value or more. In general,
the reduction of the commercial power consumption has been
implemented to stop the operation of the air-conditioning system
(for example, see Patent Document 1).
[0003] Furthermore, in a refrigerating system, a low-pressure side
pressure sensor for detecting refrigerant pressure of a
low-pressure side of a refrigerating machine is provided, and a
microcomputer contained in the refrigerating machine controls a
compressor so that the low-pressure side pressure is kept to a
predetermined set value, thereby enhancing energy saving
performance (for example, see Patent Document 2).
PRIOR ART DOCUMENT
Patent Document
[0004] Patent Document 1: JP-A-2000-186844 [0005] Patent Document
2: JP-A-62-116862
SUMMARY OF THE INVENTION
Problem to be solved by the Invention
[0006] It would be expected to further reduce the commercial power
consumption by controlling the operation of the refrigerating
system in addition to the air-conditioning system under demand
control.
[0007] However, the microcomputer contained in the refrigerating
machine controls the operation on the basis of a program which is
optimized to the construction of the refrigerating machine, and
thus it has been difficult to give the control device concerned
with an instruction of controlling power consumption from the
external.
[0008] The present invention has been implemented in view of the
foregoing situation, and has an object to provide an
air-conditioning refrigerating system that enables demand control
based on operation control of an air-conditioning system and a
refrigerating system.
Means of Solving the Problem
[0009] In order to attain the above object, there is provided an
air-conditioning system in which plural indoor units are connected
to an outdoor unit to air-condition a building, characterized by
comprising: a refrigerating system in which a plurality of
low-temperature showcases are connected to a refrigerating machine
to cool each of the low-temperature showcases; a main control
device for generating and outputting air-conditioning demand data
for varying power consumption of the air-conditioning system and
refrigerating demand data for varying power consumption of the
refrigerating system on the basis of commercial power consumption;
and an external control device that is provided separately from the
refrigerating system, receives the refrigerating demand data from
the main control device and controls an operation of the
refrigerating machine on the basis of the refrigerating demand
data.
[0010] Furthermore, according to the present invention, in the
above air-conditioning refrigerating system, the external control
device that is configured to acquire control setting required for
control of a main element for determining cooling capacity of the
refrigerating machine, and controls the main element of the
refrigerating machine on the basis of an operation state of the
refrigerating machine.
[0011] According to the present invention, in the air-conditioning
refrigerating system, the external control device is configured to
acquire, as the control setting, compressor control setting
required for capacity control of a compressor installed in the
refrigerating machine, and controls a capacity of the compressor on
the basis of low-pressure side pressure of the refrigerating
machine.
[0012] According to the present invention, in the above
air-conditioning refrigerating system, the external control device
is configured to acquire, as the control setting, condenser control
setting required for condensation capacity control of a condenser
installed in the refrigerating machine, and controls a condensation
capacity of the condenser on the basis of a high-pressure side
pressure of the refrigerating machine.
[0013] According to the present invention, in the above
air-conditioning refrigerating system, the main control device
controls the air-conditioning system in priority to the
refrigerating system on the basis of power consumption.
[0014] According to the present invention, in the above
air-conditioning refrigerating system, when the power consumption
of the refrigerating system is controlled to be varied, the main
control device controls the condensation capacity of the condenser
in priority to the capacity of the compressor.
[0015] According to the present invention, in the above
air-conditioning refrigerating system, the refrigerating machine is
a refrigerating machine that is freely constructed by selecting
main elements for determining a cooling capacity from some
types.
Effect of the Invention
[0016] According to the present invention, there is provided the
external control device that is provided separately from the
refrigerating system, receives the refrigerating demand data from
the main control device and controls the operation of the
refrigerating machine on the basis of the refrigerating demand
data. Therefore, the control of varying the power consumption can
be performed from the external main control device through the
external control device. Accordingly, the demand control having a
high power consumption reducing effect can be performed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a diagram showing the construction of an
air-conditioning refrigerating system according to an embodiment of
the present invention.
[0018] FIG. 2 is a block diagram showing the functional
construction of a main controller.
[0019] FIG. 3 is a diagram showing an example of demand control
setting.
[0020] FIG. 4 is a diagram showing an example of capacity control
setting.
[0021] FIG. 5 is a diagram showing an example of condensation
capacity control setting.
[0022] FIG. 6 is a block diagram showing the functional
construction of a compressor controller.
[0023] FIG. 7 is a block diagram showing the functional
construction of the condenser controller.
[0024] FIG. 8 is a flowchart showing demand control based on a main
controller.
[0025] FIG. 9 is a flowchart showing capacity control based on the
compressor controller.
[0026] FIG. 10 is a flowchart showing condensation capacity control
based on the condenser controller.
BEST MODE FOR CARRYING OUT THE INVENTION
[0027] An embodiment according to the present invention will be
described hereunder with reference to the drawings.
[0028] FIG. 1 is a diagram showing the construction of an
air-conditioning system 1 according to an embodiment.
[0029] As shown in FIG. 1, an air-conditioning refrigerating system
1 has an air-conditioning system 10, a refrigerating system 12, a
main controller (main control device) 4 and an external controller
(external control device) 14, and the air-conditioning system 10
and the external controller 14 are connected to the main controller
4 through a communication line 24. The air-conditioning
refrigerating system 1 is provided with a power meter 29 for
measuring the consumption commercial power of a building in which
the air-conditioning system 10 and the refrigerating system 12 are
laid, and a measurement value thereof is input to the main
controller 4.
[0030] The air-conditioning system 10 is constructed by connecting
plural indoor units 34 to outdoor units 32 through refrigerant
pipes 36, and performs air-conditioning operation of a building by
each indoor unit 34. The description will be made on the assumption
that the air-conditioning system 10 is provided with two
air-conditioning systems including mutually independent refrigerant
circuits each of which comprises an outdoor unit 32 and indoor
units 34. However, the number of systems may be arbitrary, and the
numbers of the outdoor units 32 and the indoor units 34 in each
air-conditioning system may be arbitrary.
[0031] The refrigerating system 12 has a refrigerating circuit in
which plural low-temperature showcases 7 are connected to a rack
system refrigerating machine 3 in parallel through a refrigerant
pipe 5a as a liquid pipe and a refrigerant pipe 5b as a gas
pipe.
[0032] The rack system refrigerating machine 3 has plural
compressors (compressors) 9, a condenser (condenser) 11, plural
condenser fans (fans for condensers) 13, a low-pressure side
pressure sensor 26 for detecting the refrigerant pressure at the
low-pressure side (hereinafter referred to as "low-pressure side
pressure), and a high-pressure side pressure sensor 28 for
detecting refrigerant pressure of the high-pressure side
(hereinafter referred to as "high-pressure side pressure").
[0033] Each of the compressors 9 is a capacity fixed type
compressor, and the total capacity, that is, the cooling capacity
is varied on the basis of the number of operating compressors 9.
Furthermore, the condenser 11 is a condenser which can be variably
controlled on the basis of the number of operating condenser fans
13. In the following description, the number of compressors 9 is
set to two while the number of condensers 13 is set to six,
however, these numbers are not limited to these values.
[0034] Each of the low-temperature showcase 7 has an expansion
valve (pressure reducing device) 15, and a cooling unit 17, and a
liquid electromagnetic valve 19 is connected to the inlet of the
expansion valve 15.
[0035] The liquid electromagnetic valve 19 is a valve for
controlling supply of refrigerant to the expansion valve 15, and
the in-case temperature of the low-temperature showcase 7 based on
the cooling operation of the cooling unit 17 is controlled by
opening/closing the liquid electromagnetic valve 19.
[0036] That is, the low-temperature showcase 7 has an in-case
temperature sensor 21 for detecting the in-case temperature of the
inside of the showcase and a microcomputer 23. The microcomputer 23
stores an upper limit temperature and a lower limit temperature
which are set at the upper and lower sides of an in-case set
temperature, and executes ON-OFF control of opening the liquid
electromagnetic valve 19 at the upper limit temperature and closing
the liquid electromagnetic valve 19 at the lower limit temperature.
Through the ON-OFF control concerned, the in-case temperature of
the low-temperature showcase 7 is averaged and made to approach to
the in-case set temperature. Not only the low-temperature showcases
7, but also other load facilities such as a chilling/freezing
prefabricated storage, etc. may be connected to the rack system
refrigerating machine 3.
[0037] The rack system refrigerating machine 3 is freely
constructed by freely selecting the compressors 9, the condensers 1
and the condenser fans 13 as main elements for determining the
cooling capacity from some types on the basis of the maximum
cooling capacity required for the refrigerating system 12 and
combining the selected main elements.
[0038] More specifically, the maximum cooling capacity required at
the installation place of the refrigerating system 12 is determined
on the basis of the number of low-temperature showcases 7, the
in-case set temperature, the in-store temperature and an
environmental condition such as the outside air temperature, etc.,
and a refrigerating machine which has an extra cooling capacity
with respect to the thus-determined maximum cooling capacity is
selected when the refrigerating system 12 is installed. At this
time, the maximum cooling capacity of the refrigerating machine is
determined when it is manufactured. Therefore, when a maker or the
like does not prepare any refrigerating machine having the proper
maximum cooling capacity which meets the environmental condition
when the refrigerating machine is installed, a refrigerating
machine which has a further extra cooling capacity with respect to
the maximum cooling capacity must be installed, and thus vainness
occurs in the cooling capacity.
[0039] On the other hand, according to the rack system
refrigerating machine 3 of this embodiment, the capacities of the
compressors and the condensation capacities of the condensers as
the main elements for determining the cooling capacity are freely
selected from products of the same maker or other makers by a user
in conformity with the maximum cooling capacity (thermal load)
required under the environmental condition when the rack system
refrigerating machine is installed, and the user combines these
main elements by himself/herself to freely construct the
refrigerating machine. Therefore, a refrigerating machine having
the optimum maximum cooling capacity can be constructed.
[0040] Furthermore, in the rack system refrigerating machine 3, the
main elements are combined with one another in conformity with the
required maximum cooling capacity, and thus a cooling system having
no needless cooling capacity and a high energy saving effect can be
implemented as compared with a conventional packaged refrigerating
machine.
[0041] In addition, according to the rack system refrigerating
machine 3, it is unnecessary to package constituent parts in one
housing, and thus such a layout that heat retention can be
prevented even when the condensers 11 and the condenser fans 13 are
disposed outdoors while the compressors 9 are disposed indoors.
Furthermore, the installation space is not restricted by the
housing, and the degree of freedom to determine the types of the
condensers 11 and the condenser fans 13 and the number of the
condensers 13 can be enhanced.
[0042] In the rack system refrigerating machine 3 as described
above, the types and numbers of the compressors 9, the condensers
11 and the condenser fans 13 are unstable, and thus it is difficult
that the refrigerating machine is constructed so as to contain a
microcomputer and the capacities of the compressors 9 and the
condensation capacities of the condensers 11 are controlled by the
microcomputer as in the case of a conventional refrigerating
machine. Therefore, according to the air-conditioning refrigerating
system 1 of this embodiment, the external controller 14 which
controls the main elements of the rack system refrigerating machine
3 to vary the cooling capacity is provided separately from the rack
system refrigerating machine 3.
[0043] The external controller 14 has a compressor controller 6 for
controlling the capacities of the plural compressors 9 provided to
the rack system refrigerating machine 3, and a condenser controller
8 for controlling the condensation capacities of the condensers
11.
[0044] The compressor controller 6 turns on/off each of plural
compressors 9 on the basis of refrigerating demand data described
later from the main controller 4 to vary power consumption, and the
condenser controller 8 turns on/off each of plural condenser fans
13 on the basis of the refrigerating demand data to vary power
consumption.
[0045] The main controller 4 performs so-called demand control of
integrating commercial power consumption used in a building every
demand time period (for example, 30 minutes) and reducing the
commercial power consumption so that the integration value does not
exceed a predetermined value or more. The functional construction
of the main controller 4 will be described hereunder with reference
to FIG. 2.
[0046] FIG. 2 is a block diagram showing the functional
construction of the main controller 4.
[0047] In FIG. 2, the control unit 40 centrally controls each part
of the main controller 4. Demand control setting and refrigerating
machine control setting are input to the control setting input unit
41. The demand control setting is setting information required for
the demand control of the air-conditioning refrigerating system 1,
and an example thereof is shown in FIG. 3.
[0048] FIG. 3 is a diagram showing an example of the demand control
setting.
[0049] With respect to the demand control, plural determination
timings are provided during the demand time period, and in order to
prevent the integration value from exceeding a predetermined value
at the end time of the demand time period, it is determined on the
basis of the integration value of the commercial power consumption
at each determination timing whether the power consumption is
reduced or not. With respect to the demand control setting,
integration values Wa to Wd of commercial power consumption as
threshold values for determining every determination timing Ta to
Td whether the power consumption is reduced or not, and equipment
to be stopped to reduce the power consumption are defined in
association with one another as settings required for the demand
control.
[0050] In this demand control setting, the air-conditioning system
10 is stopped in priority to the refrigerating system 12 when the
power consumption is reduced. In a case where it is still necessary
to reduce the power consumption even when all the air-conditioning
systems of the air-conditioning system 10 are stopped, only one of
the condenser fans 13 is stopped to reduce the condensation
capacity to the extent that the condensation capacity is not
nullified. Even in this case, where it is necessary to further
reduce the power consumption, only one of the compressors 9 is
stopped to reduce the capacity thereof to the extent that the
capacity is not nullified, whereby the power consumption is reduced
with keeping the cooling capacity of the rack system refrigerating
machine 3 as much as possible.
[0051] The refrigerating machine control setting represents a
setting required to control the main elements for determining the
cooling capacity so that's the cooling capacity of the rack system
refrigerating machine 3 is varied.
[0052] More specifically, according to this embodiment, the
capacity of the compressors 9 is controlled on the basis of the
refrigerant pressure of the low-pressure side of the rack system
refrigerating machine 3 (hereinafter referred to as "low-pressure
side pressure"), and the condensation capacity of the condensers 11
is controlled on the basis of the refrigerant pressure of the
high-pressure side (hereinafter referred to as "high-pressure side
pressure"). Through this control, the rack system refrigerating
machine 3 can be operated with the compressor capacity and
condensation capacity necessary and sufficient to keep a
predetermined cooling capacity under operation of the rack system
refrigerating machine 3, and the energy saving of the rack system
refrigerating machine 3 can be performed.
[0053] However, as described above, in the rack system
refrigerating machine 3, the types of numbers of the compressors 9,
the condensers 11 and the condenser fans 13 are determined when
they are installed, and thus it is impossible to preinstall a
program for controlling the compressors 9 and the condenser fans 13
into the external controller 14. Therefore, according to this
embodiment, the compressor control setting required for the
capacity control of the compressors 9 and the condenser control
setting required for the condensation capacity control of the
condensers 11 are input to the main controller 4, and output from
the main controller 4 to the external controller 14.
[0054] FIG. 4 is a diagram showing an example of the compressor
control setting.
[0055] As shown in FIG. 4, the association relationship between the
turn-on/off of each compressor 9 and the total output is defined in
the compressor control setting, and steps No. 1, step No. 2, . . .
are allocated to combinations of the turn-on/off of the respective
compressors 9 in the order of increasing the total output. That is,
when the total output is reduced to lower the cooling capacity in
the capacity control, step No. smaller than the step No.
corresponding to the combination of turn-on/off of the respective
compressors 9 at that time is selected, and the total output can be
reduced by turning on/off each compressor 9 according to the
combination defined by the selected step No. Conversely, when the
total output is increased to increase the cooling capacity, larger
step No. is selected, and each compressor 9 is turned on/off
according to the combination defined by the selected step No.,
whereby the total output can be increased.
[0056] Here, the rack system refrigerating machine 3 according to
this embodiment is provided with two capacity fixed type
compressors 9 which are different in capacity, and thus four
combinations of on/off state are obtained as shown in the figure.
At this time, when the compressors 9 have the same capacity,
combinations having the same total output occur in the four
combinations, and thus the number of the combinations having
different total outputs is reduced. However, by using compressors 9
having different capacities, the number of combinations having
different total outputs is maximized, and the total output of the
compressors 9 can be minutely controlled.
[0057] FIG. 5 is a diagram showing an example of the condenser
control setting.
[0058] As shown in FIG. 5, in the condenser control setting, the
high-pressure side pressure for cut-in/cut-out is defined in each
of the condenser fans 13, and the condenser fan 13 is regulated to
be cut in as the high-pressure side pressure increases. The
cut-in/cut-off high-pressure side pressure is provided with a
hysteresis for preventing chattering. In the condensation capacity
control, the high-pressure side pressure of the rack system
refrigerating machine 3 is monitored, a condenser fan 13 which
reaches the cut-in pressure due to variation of the high-pressure
side pressure is turned on, and a condenser fan 13 which reaches
the cut-out pressure is turned off. Accordingly, only condenser
fans 13 which meet the condensation capacity required to the rack
system refrigerating machine 3 are operated, so that the power
consumption can be reduced as compared with a case where all the
condenser fans 13 are driven.
[0059] A measurement value of the commercial power consumption of
the building is input to a power measurement value input unit 42 of
FIG. 2. The control unit 40 calculates the integration value of the
commercial power consumption for the demand time period on the
basis of the measurement value concerned, and generates
air-conditioning demand data for specifying an air-conditioning
system to be stopped (turned off) and refrigerating demand data for
specifying main elements of the rack system refrigerating machine 3
to be stopped (turned off) on the basis of the integration value
concerned and the demand control setting.
[0060] An air-conditioning communicating unit 43 transmits the
air-conditioning demand data to the air-conditioning system 10,
whereby the specified air-conditioning system is stopped and the
power consumption of the air-conditioning system 10 is reduced in
the air-conditioning system 10.
[0061] A compressor control communicating unit 44 transmits data
specifying compressors 9 as equipment to be stopped out of the
refrigerating demand data, and transmits data specifying condenser
fans 13 as equipment to be stopped out of the refrigerating demand
data. Accordingly, the specified main elements are stopped and the
power consumption is reduced in the rack system refrigerating
machine 3.
[0062] Furthermore, the compressor control setting is transmitted
from the compressor controller communicating unit 44 to the
compressor controller 6, and the condenser control setting is
transmitted from the condenser controller communicating unit 45 to
the condenser controller 8. In the compressor controller 6, the
capacity control based on the compressor control setting is
executed, and in the condenser controller 8, the condensation
capacity control based on the condenser control setting is
executed.
[0063] FIG. 6 is a block diagram showing the functional
construction of the compressor controller 6.
[0064] In FIG. 6, the control unit 60 centrally controls each part
of the compressor controller 6, and also generates a compressor
control signal for controlling turn-on/off of each of the
compressors 9 installed in the rack system refrigerating machine 3.
The control unit 60 comprises a microcomputer, for example. A
controller communicating unit 61 communicates with the main
controller 4 through the communication line 24, and receives the
compressor control setting and the refrigerating demand data. A
control setting storage unit 62 stores the compressor control
setting. The detection value of the low-pressure side pressure is
input from the low-pressure side pressure sensor 26 provided to the
rack system refrigerating machine 3 to a low-pressure side pressure
sensor input unit 63. The control unit 60 compares the detection
value of the low-pressure side pressure with the low-pressure side
pressure set value, and changes the capacity of the rack system
refrigerating machine 3 according to the compressor control
setting.
[0065] Specifically, when the low-pressure side pressure is lower
than the low-pressure side pressure set value, it indicates that a
needless cooling capacity occurs and thus the energy saving
performance is degraded. Conversely, when the low-pressure side
pressure is higher than the low-pressure side pressure set value,
it indicates that the cooling capacity lacks ad thus the cooling
performance of the low-temperature showcase 7 is damaged.
Accordingly, when the low-pressure side pressure is higher than the
low-pressure side pressure set value, the control unit 60
increments the step NO. of the capacity control rule one by one to
increase the total output and thus enhance the cooling capacity.
Conversely, when the low-pressure side pressure is lower than the
low-pressure side pressure set value, the control unit 60
decrements the step No. one by one to gradually reduce the total
output and thus lower the cooling capacity.
[0066] Then, the control unit 60 generates a control signal to
actuate only compressors 9 whose combination is indicated by the
step No. concerned.
[0067] Furthermore, when the compressors 9 are instructed to stop
on the basis of the refrigerating demand data, the control unit 60
generates a control signal for stopping one of the compressors 9
being operated.
[0068] A compressor control signal output unit 64 outputs the
compressor control signal to the compressors 9 of the rack system
refrigerating machine 3.
[0069] FIG. 7 is a block diagram showing the functional
construction of the condenser controller 8.
[0070] In FIG. 7, the control unit 80 centrally controls each part
of the condenser controller 8, and also generates a condenser fan
control signal for controlling turn-on/off of each of the condenser
fans 13 installed in the rack system refrigerating machine 3. For
example, the control unit 80 comprises a microcomputer.
[0071] A controller communicating unit 81 communicates with the
main controller 4 through the communication line 24, and receives
the condenser control setting and the refrigerating demand data. A
control setting storing unit 82 stores the control setting. The
detection value of the high-pressure side pressure is input from
the high-pressure side pressure sensor 28 provided to the rack
system refrigerating machine 3 to a high-pressure side pressure
sensor input unit 83.
[0072] The control unit 80 generates the condenser fan control
signal for turning on/off the condenser fans 13 according to the
detection value of the high-pressure side pressure and the
condenser control setting.
[0073] Furthermore, when it is instructed to stop the condenser fan
13 on the basis of the refrigerating demand data, the control unit
80 generates a control signal for stopping one of the condenser
fans 13 being operated.
[0074] A condenser fan control signal output unit 84 outputs this
condenser fan control signal to each condenser fan 13 of the rack
system refrigerating machine 3.
[0075] Next, the operation of the thus-constructed air-conditioning
refrigerating system 1 will be described.
[0076] As described above, in the air-conditioning refrigerating
system 1, the demand control is executed by the main controller 4
as described above, and also the capacity control of the
compressors 9 is executed by the compressor controller 6 and the
condensation capacity control of the condensers 11 is executed by
the condenser controller 8 in the refrigerating system 12.
[0077] FIG. 8 is a flowchart showing the demand control of the main
controller 4.
[0078] At the initial stage that the air-conditioning refrigerating
system is installed, the demand control setting based on the
construction of the rack system refrigerating machine 3 is input to
the main controller 4 by a serviceman or the like (step S1).
Subsequently, the main controller 4 resets the demand time period
to "0 minute" and then starts the time count of the lapse time
(step S2). Thereafter, when the determining timing of the demand
control described above comes (step S3: YES), the main controller 4
calculates the integration value of the commercial power consumed
till the determination timing concerned (step S4), and determines
on the basis of the demand control setting whether the integration
value exceeds a threshold value (step S5). When the integration
value exceeds the threshold value (step S5: YES), the main
controller 4 generates and outputs air-conditioning demand data
or/and refrigerating demand data on the basis of the demand control
setting to reduce the power consumption (step S6). Accordingly, the
air-conditioning system, the compressor 9 or the condenser fan 13
is stopped to reduce the power consumption.
[0079] Subsequently, the main controller 4 determines whether the
demand time period is finished or not (for example, 30 minutes
elapses or not) (step S7). When the demand time period is not
finished (step S7: NO), the main controller 4 returns the
processing procedure to the step S3 to perform the determination at
the next determination timing. When the demand time period is
finished (step S7: YES), there is no problem even if each equipment
which has been stopped within this demand time period because of
reduction of the power consumption is started, and thus the main
controller 4 generates and outputs data for starting these
equipment (step S8). The main controller 4 returns the processing
procedure to the step S2 to perform the demand control for the next
demand time period.
[0080] FIG. 9 is a flowchart showing the capacity control of the
compressor controller 6.
[0081] As shown in FIG. 9, the compressor controller 6 acquires
low-pressure side pressure from the low-pressure side pressure
sensor 26 of the rack system refrigerating machine 3 every fixed
time (step S10), and compares the acquired low-pressure side
pressure with the low-pressure side pressure set value (step S11).
When the low-side pressure exceeds the low-pressure side pressure
set value and the cooling capacity of the rack system refrigerating
machine Slacks (step S11: YES), in order to increase the cooling
capacity and keep the cooling performance of the low-temperature
showcase 7, the step No. of the condenser control setting is
incremented by "1" (step S12), and the compressor control signal
based on the condenser control setting is generated and output to
the compressor 9 (step S13).
[0082] Furthermore, when the low-pressure side pressure falls below
the low-pressure side pressure set value and thus a surplus cooling
capacity occurs in the rack system refrigerating machine 3 (step
S11: NO), in order to lower the cooling capacity and reduce the
power consumption of the rack system refrigerating machine 3, the
step No. of the condenser control setting is decremented by "1"
(step S14), and the compressor control signal based on the
condenser control setting is generated and output to the
compressors 9 (step S13).
[0083] When it is determined whether the low-pressure side pressure
exceeds the low-pressure side pressure set value, the low-pressure
side pressure set value as a determination criterion is provided
with a hysteresis. That is, when the low-pressure side pressure
exceeds a pressure which is higher than the low-pressure side
pressure set value by only a predetermined value, "exceeding" is
determined. When the low-pressure side pressure falls below a
pressure which is lower than the low-pressure side pressure set
value by only a predetermined value, "falling below" is determined.
The predetermined values may be transmitted from the main
controller 4 to the compressor controller 6 together with the
low-pressure side pressure set value, or preinstalled in a program
of the compressor controller 6 together with the low-pressure side
pressure set value.
[0084] Subsequently, the compressor controller 6 determines whether
the refrigerating demand data is received (step S15). When no
refrigerating demand data is received (step S15: NO), the
compressor controller 6 returns the processing procedure to the
step S1. When the refrigerating demand data is received (step S15:
YES), the compressor controller 6 outputs a compressor control
signal for stopping one of the compressors 9 under operation (step
S16). Accordingly, through the demand control, the compressor 9 is
stopped and the power consumption is reduced.
[0085] FIG. 10 is a flowchart showing the condensation capacity
control of the condenser controller 8.
[0086] As shown in FIG. 10, the condenser controller 8 acquires
high-pressure side pressure from the high-pressure side pressure
sensor 28 of the rack system refrigerating machine 3 every fixed
time (step S20). The condenser controller 8 determines on the basis
of this high-pressure side pressure and the condenser control
setting whether there is any condenser fan 13 to be turned on/off
to vary the condensation capacity (step S21). When there is any
condensation fan 13, the condenser controller 8 generates the
condenser control signal for turning on/off the condenser fan 13
concerned, and outputs the condenser control signal to the
condenser fan 13 (step S22).
[0087] Subsequently, the condenser controller 8 determines whether
any refrigerating demand data is received (step S23). When no
refrigerating demand data is received (step S23: NO), the condenser
controller 8 directly returns the processing procedure to the step
S1. When refrigerating demand data is received (step S23: YES), the
condenser controller 8 generates and outputs a condenser fan
control signal for stopping one of the condenser fans 13 being
operated (step s24). Accordingly, through the demand control, the
condenser fan 13 is stopped and the power consumption is
reduced.
[0088] As described above, according to this embodiment, there is
provided the external controller 14 which is provided separately
from the refrigerating system 12, receives the refrigerating demand
data from the main controller 4 and controls the operation of the
rack system refrigerating machine 3 on the basis of the
refrigerating demand data. Therefore, the control for varying the
power consumption can be performed from the external main
controller 4 through the external controller 14. Accordingly, the
demand control having a higher power consumption reducing effect
can be performed as compared with the prior art in which only the
air-conditioning system 10 is subjected to the demand control.
[0089] Furthermore, according to this embodiment, the external
controller 14 acquires the control setting required for the
capacity control of the compressors 9 and the condensation capacity
control of the condensers 11, and controls to vary the cooling
capacity on the basis of the operation state (the low-pressure side
pressure and the high-pressure side pressure) of the rack system
refrigerating machine 3. Therefore, the energy saving performance
of the rack system refrigerating machine 3 can be more
enhanced.
[0090] Particularly, the rack system refrigerating machine 3 is
constructed by selecting the compressors 9 and the condensers 11
for arbitrarily determining the cooling capacity from some types
thereof and freely installing the selected compressors 9 and
condensers 11. Therefore, the optimum refrigerating machine in
which no needless cooling capacity occurs with respect to the
required cooling capacity can be constructed.
[0091] In addition, in the rack system refrigerating machine 3
described above, it is difficult to control the cooling capacity of
a built-in microcomputer. However, according to this embodiment,
the external controller 14 is provided and thus the cooling
capacity control can be implemented.
[0092] Furthermore, the above-described embodiment is merely an
example of the present invention, and it may be arbitrarily
modified and applicable within the scope of the present
invention.
DESCRIPTION OF REFERENCE NUMERALS
[0093] 1 air-conditioning refrigerating system [0094] 2
refrigerating circuit [0095] 3 rack system refrigerating machine
(refrigerating machine) [0096] 4 main controller (main control
device) [0097] 6 compressor controller [0098] 7 low-temperature
showcase [0099] 8 condenser controller [0100] 9 compressor [0101]
10 air-conditioning system [0102] 11 condenser [0103] 12
refrigerating system [0104] 13 condenser fan [0105] 14 external
controller (external control device) [0106] 26 low-pressure side
pressure sensor [0107] 28 high-pressure side pressure sensor [0108]
29 power meter [0109] 32 outdoor unit [0110] 34 indoor unit
* * * * *