CN115398158A - Air conditioning system and control method - Google Patents
Air conditioning system and control method Download PDFInfo
- Publication number
- CN115398158A CN115398158A CN202080099724.XA CN202080099724A CN115398158A CN 115398158 A CN115398158 A CN 115398158A CN 202080099724 A CN202080099724 A CN 202080099724A CN 115398158 A CN115398158 A CN 115398158A
- Authority
- CN
- China
- Prior art keywords
- temperature
- indoor
- humidity
- heat exchanger
- unit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000004378 air conditioning Methods 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims abstract description 33
- 239000003507 refrigerant Substances 0.000 claims abstract description 68
- 238000001514 detection method Methods 0.000 claims abstract description 46
- 230000007423 decrease Effects 0.000 claims description 33
- 238000007791 dehumidification Methods 0.000 abstract description 16
- 238000001816 cooling Methods 0.000 description 25
- 239000007788 liquid Substances 0.000 description 24
- 238000010586 diagram Methods 0.000 description 17
- 230000003247 decreasing effect Effects 0.000 description 16
- 230000008569 process Effects 0.000 description 13
- 238000001704 evaporation Methods 0.000 description 12
- 230000008020 evaporation Effects 0.000 description 12
- 238000004891 communication Methods 0.000 description 9
- 238000001035 drying Methods 0.000 description 7
- 230000006870 function Effects 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 238000012546 transfer Methods 0.000 description 4
- 230000005514 two-phase flow Effects 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000013459 approach Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 238000007792 addition Methods 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000012217 deletion Methods 0.000 description 1
- 230000037430 deletion Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000035807 sensation Effects 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/70—Control systems characterised by their outputs; Constructional details thereof
- F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
- F24F11/83—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers
- F24F11/84—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers using valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/70—Control systems characterised by their outputs; Constructional details thereof
- F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
- F24F11/86—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling compressors within refrigeration or heat pump circuits
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B1/00—Compression machines, plants or systems with non-reversible cycle
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
Abstract
Provided are a system and a method which can suppress a temperature drop during a dehumidification operation for each indoor unit and which do not cause a reduction in dehumidification capacity even under low load. Regarding the air conditioning system, the indoor unit includes: an indoor heat exchanger; a temperature detection unit that detects a temperature in the room; and a humidity detection unit that detects humidity in the room, the outdoor unit including: an outdoor heat exchanger; and a compressor that circulates a refrigerant with the indoor unit, the air conditioning system including: a valve disposed between the outdoor heat exchanger and the indoor heat exchanger; a rotation speed control means (32) for controlling the rotation speed of the compressor on the basis of the temperature detected by the temperature detection means; and an opening degree control means (33) for controlling the opening degree of the valve on the basis of the humidity detected by the humidity detection means.
Description
Technical Field
The present invention relates to an air conditioning system and a method of controlling operation of the air conditioning system.
Background
Among air conditioning systems, there is a system having a dehumidification (drying) mode in addition to a cooling mode. In the dry mode operation, a method of reducing the amount of air blown to a heat exchanger (evaporator) and setting the upper limit temperature of the evaporator to be low to improve latent heat capacity is generally widely used.
In such a system, there are problems as follows: it is necessary to select a cooling mode in which temperature adjustment is important or a drying mode in which humidity adjustment is important, and when the cooling mode is selected, humidity tends to increase, and when the drying mode is selected, room temperature tends to decrease.
Patent document 1 describes a method of setting the upper limit temperature of the evaporator to be low based on the detection value of the relative humidity sensor. In contrast, patent document 2 describes the following apparatus: in order to perform cooling operation and also enable dehumidification, while the humidity detected by the temperature/humidity sensor is higher than a predetermined value, the suction pressure is calculated so that the surface temperature of the evaporator becomes a predetermined temperature lower than the dew point of the suction air, and the opening degree of the electronic expansion valve is adjusted so as to become the calculated suction pressure.
Documents of the prior art
Patent document
Patent document 1: international publication No. 03/029728
Patent document 2: japanese laid-open patent publication No. 6-257865
Disclosure of Invention
Problems to be solved by the invention
However, in the method described in patent document 1, when the drying mode is selected, not only the room temperature is liable to decrease, but also when the compressor is operated at a low load in the vicinity of the minimum rotation speed, the evaporation temperature of the heat exchanger is kept high, and therefore, there is a problem that the dehumidification capability is deteriorated. In the method of calculating the target temperature of the evaporator from the suction pressure of the compressor as in patent document 2, if the target temperatures of the indoor units having different pipe lengths are calculated from the suction pressure of the compressor when a plurality of indoor units are simultaneously connected, the dehumidification capacity may be insufficient due to the pipe length.
Accordingly, it is desirable to provide a system and a method for promoting dehumidification while suppressing cooling capacity for each indoor unit.
Means for solving the problems
The present invention has been made in view of the above problems, and provides an air conditioning system including an indoor unit and an outdoor unit,
the indoor unit includes:
an indoor heat exchanger;
a temperature detection unit that detects a temperature in the room;
a humidity detection unit which detects humidity in the room,
the outdoor unit includes:
an outdoor heat exchanger;
a compressor for circulating a refrigerant with the indoor unit,
the air conditioning system includes:
a valve disposed between the outdoor heat exchanger and the indoor heat exchanger;
a rotation speed control means for controlling the rotation speed of the compressor based on the temperature detected by the temperature detection means;
and an opening control means for controlling the opening of the valve based on the humidity detected by the humidity detection means.
Effects of the invention
According to the present invention, it is possible to provide a system and a method that can suppress a temperature decrease during a dehumidification operation for each indoor unit and that do not cause a decrease in dehumidification capacity even under low load.
Drawings
Fig. 1 is a diagram showing a first configuration example of an air conditioning system.
Fig. 2 is a diagram showing an example of a hardware configuration of a control device provided in the outdoor unit.
Fig. 3 is a control block diagram illustrating first control of the frequency of the compressor and the opening degree of the indoor expansion valve.
Fig. 4 is a diagram showing a state of room temperature after the start of operation of the air conditioning system.
Fig. 5 is a diagram showing a state of humidity after the start of operation of the air conditioning system.
Fig. 6 is a flowchart showing a first example of control of the indoor expansion valve.
Fig. 7 is a diagram showing a second configuration example of the air conditioning system.
Fig. 8 is a flowchart showing a second example of control of the indoor expansion valve.
Fig. 9 is a diagram showing a third configuration example of the air conditioning system.
Fig. 10 is a flowchart showing a third example of control of the indoor expansion valve.
Fig. 11 is a control block diagram for explaining the second control of the frequency of the compressor and the opening degree of the indoor expansion valve.
Fig. 12 is a diagram showing a fourth configuration example of the air conditioning system.
Detailed Description
Fig. 1 is a diagram showing a first configuration example of an air conditioning system. An air conditioning system is a system for adjusting the indoor temperature, humidity, and the like of a house, a building, and the like, and includes an indoor unit 10 installed indoors and an outdoor unit 20 installed outdoors.
The indoor unit 10 and the outdoor unit 20 are connected by refrigerant pipes 30 and 31 through which a refrigerant as a heat medium circulates. As the refrigerant, for example, hydrofluorocarbons such as R410a and R32 are used. The indoor unit 10 and the outdoor unit 20 are connected by a communication cable or the like for mutual communication. The communication is not limited to wired communication using a communication cable, and may be wireless communication using WiFi (registered trademark) or the like.
An operation device (remote controller) for a user to operate is disposed in the room. The indoor unit 10 receives an operation of the remote controller by a user, and receives an instruction to start or end an operation, an operation mode, a change in set temperature, and the like. When receiving an instruction to start operation, the indoor unit 10 instructs the outdoor unit 20 to start circulation of the refrigerant. The indoor unit 10 also notifies the outdoor unit 20 of the received operation mode, set temperature, and the like.
The indoor unit 10 includes: an indoor heat exchanger 11, a blower (fan) 12, a room temperature sensor 13 as a temperature detection unit that detects the temperature in the room (room temperature), and a humidity sensor 14 as a humidity detection unit that detects the humidity in the room. In addition, the indoor unit 10 includes: and an indoor expansion valve 15 that expands the refrigerant flowing through the indoor heat exchanger 11 and adjusts the flow rate of the refrigerant. The indoor unit 10 includes: a control device, not shown, controls the fan 12 to set the air volume, and notifies the outdoor unit 20 of instructions for start and end of operation, and detection results of the room temperature sensor 13 and the like.
Upon receiving an operation start command, the indoor unit 10 activates the fan 12 and takes in indoor air by the fan 12. The indoor heat exchanger 11 exchanges heat between the air taken in by the fan 12 and the refrigerant supplied from the outdoor unit 20, and blows out cooled air or heated air. The indoor unit 10 repeats this operation, and cools or heats the inside of the room to a set temperature.
The control device acquires the room temperature detected by the room temperature sensor 13 and the humidity detected by the humidity sensor 14 as detection values and notifies the outdoor unit 20 of the detection values. The indoor expansion valve 15 is controlled by the outdoor unit 20 to change the opening degree, expand the refrigerant flowing through the indoor heat exchanger 11, and adjust the flow rate of the refrigerant. The indoor expansion valve 15 is provided on the refrigerant inlet side of the indoor heat exchanger 11 when used in the cooling mode. The indoor expansion valve 15 is provided on the refrigerant inlet side of the indoor heat exchanger 11 when used in the cooling mode, and may be provided at any position within the indoor unit 10.
The outdoor unit 20 is activated in response to a command from the indoor unit 10, and starts operation in an operation mode set or notified from the indoor unit 10. The operation mode is a cooling mode, a heating mode, an air blowing mode, or the like. The outdoor unit 20 includes a compressor 21, an outdoor heat exchanger 22, and a controller 23. The outdoor unit 20 further includes a fan, an outdoor expansion valve, and a four-way valve, which are not shown.
The controller 23 starts the compressor 21 and the fan, switches the four-way valve according to the operation mode, and starts control of the compressor 21, the fan, the outdoor expansion valve, and the indoor expansion valve 15. The compressor 21 circulates a refrigerant between the indoor unit 10 and the outdoor unit 20 through refrigerant pipes 30 and 31. The outdoor heat exchanger 22 exchanges heat between the outside air taken in by the fan and the refrigerant discharged from the compressor 21 or returned from the indoor unit 10. The outdoor expansion valve expands the refrigerant condensed by the outdoor heat exchanger 22 or the indoor unit 10, and adjusts the flow rate of the refrigerant. The control device 23 receives a command from the indoor unit 10, stops the compressor 21 and the fan, and stops the operation.
In the case of operation in the cooling mode, the high-temperature gaseous refrigerant discharged from the compressor 21 is supplied to the outdoor heat exchanger 22 functioning as a condenser via the four-way valve, condensed, expanded by the indoor expansion valve 15 into a two-phase flow in which gas and liquid are mixed, and then supplied to the indoor heat exchanger 11 after the temperature is reduced. The refrigerant exchanges heat with indoor air in the indoor heat exchanger 11 and evaporates, and the refrigerant in the gas form discharged from the indoor unit 10 returns to the compressor 21 via the four-way valve.
When the operation is performed in the heating mode, the direction of the refrigerant flow is reversed by switching the four-way valve, and the refrigerant in the gas state discharged from the compressor 21 is supplied to the indoor unit 10. In the indoor unit 10, the refrigerant is condensed by heat exchange with indoor air in the indoor heat exchanger 11 functioning as a condenser, and is sent to the outdoor unit 20 through the indoor expansion valve 15. The refrigerant is expanded by the outdoor expansion valve 24, evaporated by the outdoor heat exchanger 22 functioning as an evaporator, and returned to the compressor 21 via the four-way valve 25 as a gaseous refrigerant.
In this example, the control of the compressor 21, the outdoor expansion valve, and the indoor expansion valve 15 is performed by the control device 23 of the outdoor unit 20, but the present invention is not limited thereto, and these controls may be performed by a control device of the indoor unit 10, a separately provided centralized controller, or the like.
Fig. 2 is a diagram showing an example of a hardware configuration of the control device 23 included in the outdoor unit 20. The control device 23 includes: CPU40, flash memory 41, RAM42, communication I/F43, and control I/F44. The components such as the CPU40 are connected to a bus 45, and exchange information and the like is performed via the bus 45.
The flash memory 41 stores programs executed by the CPU40, various data, and the like. The RAM42 provides the CPU40 with a work area. The CPU40 realizes the above-described control by reading out the program stored in the flash memory 41 into the RAM42 and executing it.
The communication I/F43 is connected to the indoor unit 10, and receives information such as room temperature and humidity from the indoor unit 10. The control I/F44 is connected to the compressor 21, the fan, the outdoor expansion valve, the four-way valve, and the indoor expansion valve 15, and controls the respective devices.
Fig. 3 is a control block diagram for explaining the first control of the frequency of the compressor 21 and the opening degree of the indoor expansion valve 15. The control device 23 includes: and a rotational speed control means 32 for calculating the frequency of the ac power supply input to the compressor 21 based on the temperature difference between the set temperature and the detection value of the room temperature sensor 13 of the indoor unit 10. The rotational speed control unit 32 is realized by the CPU40 shown in fig. 2 executing a program read out from the flash memory 41. The rotation speed control means described above is realized by the CPU40 executing a program, but the present invention is not limited thereto, and may be realized by hardware such as a circuit. This is also true for the following opening degree control unit and the like.
The compressor 21 has a motor, and the motor is connected to an inverter. An inverter is a device that converts the voltage and frequency of a commercial power supply into a desired voltage and frequency and outputs the voltage and frequency. The rotational speed control unit 32 inputs the calculated frequency to the inverter, and inputs an electric signal converted into the frequency by the inverter to the motor. Thereby, the rotation speed control unit 32 controls the rotation speed of the motor included in the compressor 21. The frequency may be calculated using a correspondence table in which the temperature difference and the frequency are associated with each other, or using a calculation expression in which the temperature difference is used as a variable.
The control device 23 maintains the target humidity in addition to the set temperature set by the user. The target humidity is a humidity set by a user as a target. The control device 23 includes: and an opening degree control means 33 for calculating the opening degree of the indoor expansion valve 15 based on the difference between the target humidity and the detection value of the humidity sensor 14 of the indoor unit 10. The opening degree control unit 33 inputs the calculated opening degree information to the indoor expansion valve 15 as an electric signal, and controls the opening degree of the indoor expansion valve 15. The calculation of the opening degree may use a correspondence table in which the difference in humidity is associated with the opening degree, or may use a calculation expression in which the difference in humidity is used as a variable, as in the calculation of the frequency.
The motor and the indoor expansion valve 15 are actuators that convert an input electric signal into a rotational motion or the like, and the motor rotates at a predetermined rotational speed, so that the indoor expansion valve 15 is adjusted to a predetermined opening degree. The compressor 21 is a rotary compressor, a scroll compressor, or the like, and compresses a refrigerant taken into a cylinder by rotating a crankshaft by rotation of a motor.
However, when the detected value of the room temperature sensor 13 approaches the set temperature and the temperature difference between the room temperature and the set temperature becomes small, the control device 23 performs control so as to reduce the frequency of the compressor 21 and reduce the circulation amount of the refrigerant. The compressor 21 has the lowest rotational speed at which it can be operated and is stopped when it falls below the lowest rotational speed (thermocouple is turned off). When the compressor 21 is stopped, the circulation of the refrigerant is also stopped, and the temperature in the room is increased in the case of the cooling operation. Then, the temperature difference between the room temperature and the set temperature becomes large, and the controller 23 starts the operation of the compressor 21 (the thermocouple is turned on). As the room temperature approaches the set temperature, the compressor 21 is operated near the minimum rotation speed, and the intermittent operation in which the thermocouple is turned on and off is repeated is performed.
Since the compressor 21 consumes much electric power at the time of starting, if the intermittent operation occurs, the electric power consumption increases compared to the continuous operation. In addition, compared with the continuous operation, the intermittent operation reduces the efficiency and reliability of the equipment, and the indoor temperature also fluctuates, thereby impairing the comfort. Therefore, if intermittent operation can be avoided, it is desirable to avoid intermittent operation.
The amount of air blown by the fan 12 to the indoor heat exchanger 11 is reduced, and the evaporation temperature of the refrigerant flowing through the indoor heat exchanger 11 is set low, thereby reducing the indoor humidity. Specifically, when the air volume of the fan 12 is decreased, the evaporation temperature decreases, and the cooling capacity does not change, so the temperature of the air decreases. When the temperature of the air is lower than the dew point due to the decrease in the temperature of the air, water vapor in the air condenses, and thus the humidity in the room decreases.
However, in this method, the temperature of the air is also lowered, and therefore, the room temperature is likely to be lowered. In order to suppress a decrease in the room temperature, it is necessary to decrease the circulation amount of the refrigerant, but when the compressor 21 is operated at the lowest rotation speed, the rotation speed cannot be further decreased, and therefore, the circulation amount of the refrigerant cannot be decreased.
Therefore, the flow rate of the refrigerant flowing through the indoor heat exchanger 11 is reduced by using the indoor expansion valve 15, instead of reducing the rotation speed of the compressor 21. That is, the opening degree of the indoor expansion valve 15 is decreased to decrease the flow rate of the refrigerant.
Since the cooling capacity decreases by decreasing the flow rate of the refrigerant flowing through the indoor heat exchanger 11, a decrease in the room temperature can be suppressed. Further, by suppressing the decrease in the room temperature, the compressor 21 does not need to decrease the circulation amount of the refrigerant, and does not need to decrease the rotation speed to a rotation speed lower than the minimum rotation speed even at the time of low load, and therefore, the intermittent operation can be avoided.
Here, the reason why the cooling capacity is reduced will be described. When the opening degree of the indoor expansion valve 15 is decreased, the mass flow rate decreases and the evaporation temperature of the refrigerant decreases as the expansion-valve outlet-side pressure decreases. At this time, the temperature difference between the air temperature and the evaporation temperature is increased, and the heat exchange amount is increased, so that the liquid refrigerant is rapidly and completely vaporized in the heat exchanger. In the cooling operation, the indoor heat exchanger 11 functions as an evaporator, and cools the air mainly by using vaporization heat generated when the liquid component in the refrigerant evaporates. The indoor heat exchanger 11 has a plurality of heat transfer pipes, and the effective area is defined according to the ratio of the liquid component in the heat transfer pipes. When the flow rate of the refrigerant is reduced and the liquid component in the refrigerant is reduced by expansion, the effective area is reduced, and therefore, the cooling capacity is reduced.
Further, when the opening degree of the indoor expansion valve 15 is decreased, the temperature of the refrigerant decreases, and therefore, the temperature of the air in contact with the heat transfer pipe can be decreased. Therefore, the water vapor contained in the air in contact with the heat transfer pipe is condensed more, and as a result, the amount of the water vapor contained in the air as a whole can be reduced, and dehumidification can be performed.
Fig. 4 is a diagram showing a state of room temperature after the start of operation of the air conditioning system. In fig. 4, the solid line shows the result of the present control, the broken line shows the result of the cooling operation, and the alternate long and short dash line shows the result of the operation in the drying mode. In fig. 4, the target temperature as the set temperature is also shown.
In the cooling operation, the room temperature at the start of the operation is rapidly decreased to the set temperature, but a certain time is required until the temperature becomes stable. In the dry mode operation, the room temperature decreases beyond the set temperature. In this control, the rate of decrease to the set temperature is slower than in the cooling operation, but the temperature is stabilized faster than in the cooling operation, and the temperature fluctuation after stabilization is also reduced. Therefore, the temperature can be stably adjusted by this control.
Fig. 5 is a diagram showing the state of the humidity in the room after the start of the operation of the air conditioning system. In fig. 5, the solid line shows the result of the present control, the broken line shows the result of the cooling operation, and the alternate long and short dash line shows the result of the operation in the drying mode. The target humidity is also shown in fig. 5. Humidity is relative humidity and is expressed by the ratio of the partial pressure of water vapor contained in air at room temperature to the maximum partial pressure of water vapor that can be contained in air at room temperature.
Since the cooling operation is an operation in which dehumidification is not performed, the humidity in the room is not reduced to the target humidity. In the dry mode operation, dehumidification is performed without reducing the flow rate of the refrigerant flowing through the indoor heat exchanger 11, and therefore the indoor humidity quickly reaches the target humidity. In this control, the flow rate of the refrigerant flowing through the indoor heat exchanger 11 is reduced by the indoor expansion valve 15 to perform dehumidification, and therefore, it takes time compared to the dry mode operation, but the indoor humidity can be reduced to the target humidity, and the target humidity can be maintained. Therefore, the humidity can be stably adjusted by the present control.
From these results, as in the present control, by independently controlling the frequency of the compressor 21 and the opening degree of the indoor expansion valve 15, respectively, it is possible to prevent the humidity from increasing during cooling and prevent the room temperature from decreasing during the drying mode.
A specific control will be described with reference to fig. 6. Fig. 6 is a flowchart illustrating a first example of control of the indoor expansion valve 15. Upon receiving the start of the operation of the outdoor unit 20, the control device 23 starts the control of the compressor 21, the indoor expansion valve 15, and the like. The control of the indoor expansion valve 15 is started in step 100, and in step 101, the detection value RH detected by the humidity sensor 14 is compared with the set target humidity RHo, and it is determined whether RH is greater than RHo.
If it is determined in step 101 that RH is greater than RHo, the process proceeds to step 102, where the opening degree of the indoor expansion valve 15 is commanded to decrease. This is to suppress a decrease in room temperature and to reduce humidity. Further, information of an opening degree smaller than the current opening degree calculated from the difference between the detection value of the humidity sensor 14 and the target humidity is given to the indoor expansion valve 15 as an electric signal. Then, the control returns to step 101 to continue the control.
When it is determined in step 101 that RH is equal to or less than RHo, the process proceeds to step 103, where it is determined whether RH is smaller than RHo. If it is determined that RH is smaller than RHo, the routine proceeds to step 104, where the indoor expansion valve 15 is commanded to increase the opening degree in order to suppress a decrease in humidity. In this case, the information of the opening degree larger than the current opening degree obtained by the calculation is given to the indoor expansion valve 15. Then, the process returns to step 101 to continue the control.
If it is determined in step 103 that RH is the same as RHo, the process proceeds to step 105, and the indoor expansion valve 15 is commanded to maintain the opening degree because the indoor humidity is maintained at the target humidity. In this case, information on the current opening degree may be given to the indoor expansion valve 15, or may not be given because the opening degree is not changed. Then, the control returns to step 101 to continue the control. This control is continued until the operation of the air conditioning system is stopped.
In the above, an example has been described in which the opening degree of the indoor expansion valve 15 is directly commanded to be increased or decreased so as to control the target humidity, but the control for achieving the target humidity is not limited to this. Hereinafter, control for providing another method will be described.
Fig. 7 is a diagram showing a second configuration example of the air conditioning system. The configuration shown in fig. 7 is such that, in the configuration shown in fig. 1, the indoor unit 10 further includes 2 piping temperature sensors 16 and 17. The indoor heat exchanger 11, the fan 12, and the like of the indoor unit 10, the compressor 21, the outdoor heat exchanger 22, and the like of the outdoor unit 20 have been described, and therefore only the 2 pipe temperature sensors 16 and 17 will be described here.
The 2 pipe temperature sensors 16 and 17 are attached adjacent to the outer wall surfaces of the 2 pipes connected to the indoor heat exchanger 11, and detect the temperatures of the pipe outer wall surfaces. The 2 pipe temperature sensors 16 and 17 are attached to the outer wall surfaces of the respective pipes in proximity to the 2 connection portions connecting the indoor heat exchanger 11 and the 2 pipes, respectively.
When the indoor heat exchanger 11 is caused to function as an evaporator in the cooling mode, the pipe temperature sensor 16 functions as a liquid pipe temperature sensor that detects the temperature of the outer wall surface of the pipe through which the two-phase flow refrigerant flowing through the indoor expansion valve 15 flows. The pipe temperature sensor 17 functions as a gas pipe temperature sensor that detects the temperature of the outer wall surface of the pipe through which the gaseous refrigerant evaporated by the indoor heat exchanger 11 and discharged from the indoor heat exchanger 11 flows.
The temperature of the refrigerant in the two-phase flow (the saturation temperature or the evaporation temperature of the refrigerant) can be obtained from the detection value of the pipe temperature sensor 16 functioning as a liquid pipe temperature sensor. The temperature of the refrigerant gas, which is evaporated and heated by the refrigerant, can be obtained from the detection value of the pipe temperature sensor 17 functioning as a gas pipe temperature sensor. The difference between the temperature of the obtained refrigerant gas and the saturation temperature of the obtained refrigerant is called the degree of superheat.
The control device 23 calculates the degree of superheat based on the detection values of the pipe temperature sensors 16 and 17, and controls the opening degree of the indoor expansion valve 15 by commanding an increase or decrease in the degree of superheat or maintaining the degree of superheat. A specific control will be described with reference to fig. 8.
Fig. 8 is a flowchart showing a second example of control of the indoor expansion valve 15. Upon receiving the start of the operation of the outdoor unit 20, the control device 23 starts the control of the compressor 21, the indoor expansion valve 15, and the like. Control of the indoor expansion valve 15 is started in step 200, and in step 201, the detection value RH detected by the humidity sensor 14 is compared with the target humidity RHo to determine whether RH is greater than RHo.
If it is determined in step 201 that RH is greater than RHo, the process proceeds to step 202, where the indoor expansion valve 15 is commanded to increase the degree of superheat. The degree of superheat can be increased by increasing the temperature of the refrigerant gas flowing out of the indoor heat exchanger 11, by decreasing the saturation temperature (evaporation temperature) of the refrigerant, or by both of these. In order to increase the temperature of the refrigerant gas, the liquid component in the refrigerant needs to be reduced, and in order to decrease the evaporation temperature, the pressure of the refrigerant needs to be decreased. This can be achieved by reducing the opening degree of the indoor expansion valve 15. When RH is larger than RHo, as described with reference to fig. 6, the opening degree of the indoor expansion valve 15 needs to be decreased, and the degree of superheat is commanded to be increased in order to perform control so as to decrease the opening degree.
The control device 23 gives information of the degree of superheat, which is calculated from the detection values of the pipe temperature sensors 16 and 17 and is larger than the current degree of superheat, to the indoor expansion valve 15 as an electric signal. The indoor expansion valve 15 holds a table or the like in which the degree of superheat is associated with the opening degree, for example, obtains the opening degree using the table or the like, and adjusts the opening degree to this opening degree. Then, the control is continued by returning to step 201.
If it is determined in step 201 that RH is equal to or less than RHo, the process proceeds to step 203, where it is determined whether RH is smaller than RHo. When it is determined that RH is smaller than Rho, the routine proceeds to step 204, and conversely, the indoor expansion valve 15 is commanded to decrease the degree of superheat in order to control the opening degree to increase. The controller 23 gives information on the degree of superheat smaller than the calculated current degree of superheat to the indoor expansion valve 15 as an electric signal. Then, the control is continued by returning to step 201.
If it is determined in step 203 that RH is the same as RHo, the process proceeds to step 205, where the indoor expansion valve 15 is commanded to maintain the current superheat degree. This is because the target humidity is maintained at the current degree of superheat. In this case, the information on the current degree of superheat may be given to the indoor expansion valve 15, or may not be given. Then, the process returns to step 201 to continue the control. This control is similarly continued until the operation of the air conditioning system is stopped.
Fig. 9 is a diagram showing a third configuration example of the air conditioning system. The configuration shown in fig. 9 is a configuration in which the piping temperature sensor 17 of the indoor unit 10 is removed from the configuration shown in fig. 7. That is, the indoor heat exchanger 11 is configured to include only the pipe temperature sensor 16, and the pipe temperature sensor 16 functions as a liquid pipe temperature sensor when the indoor heat exchanger 16 is used as an evaporator.
The pipe temperature sensor 16 detects the temperature of the outer wall surface of the pipe, in which the two-phase flow refrigerant flowing through the indoor expansion valve 15 flows, that is, the liquid pipe temperature. The evaporation temperature of the refrigerant can be determined from the liquid pipe temperature.
The control device 23 commands the liquid pipe temperature to increase or decrease, or maintains the liquid pipe temperature, and controls the opening degree of the indoor expansion valve 15. A specific control will be described with reference to fig. 10.
Fig. 10 is a flowchart showing a third example of control of the indoor expansion valve 15. The control shown in fig. 10 is a control using the pipe temperature sensor 16 shown in fig. 9. Upon receiving the start of the operation of the outdoor unit 20, the control device 23 starts the control of the compressor 21, the indoor expansion valve 15, and the like. Control of the indoor expansion valve 15 is started in step 300, and in step 301, the detection value RH detected by the humidity sensor 14 is compared with the target humidity RHo to determine whether RH is greater than RHo.
If it is determined in step 301 that RH is greater than Rho, the process proceeds to step 302, where the liquid pipe temperature is commanded to decrease. The liquid tube temperature is related to the evaporation temperature of the refrigerant and can be reduced by lowering the evaporation temperature. The evaporation temperature can be lowered by lowering the pressure of the refrigerant, and can be achieved by reducing the opening degree of the indoor expansion valve 15. When RH is larger than Rho, the opening degree of the indoor expansion valve 15 needs to be decreased, and the liquid pipe temperature is commanded to be decreased in order to perform control so as to decrease the opening degree.
The control device 23 gives information of a liquid pipe temperature lower than the current liquid pipe temperature calculated from the detection value of the pipe temperature sensor 16 to the indoor expansion valve 15 as an electric signal. The indoor expansion valve 15 holds a table or the like in which the liquid pipe temperature and the opening degree are associated with each other, obtains the opening degree using the table or the like, and adjusts the opening degree. Then, the control returns to step 301 to continue the control.
If it is determined in step 301 that RH is equal to or less than RHo, the process proceeds to step 303, where it is determined whether RH is smaller than RHo. If it is determined that RH is smaller than Rho, the process proceeds to step 304, and conversely, the liquid tube temperature is commanded to increase in order to control the opening degree to increase. The controller 23 gives information on the liquid pipe temperature higher than the calculated current liquid pipe temperature to the indoor expansion valve 15 as an electric signal. Then, the control returns to step 301 to continue the control.
If it is determined in step 303 that RH is the same as RHo, the process proceeds to step 305, where the current liquid pipe temperature is maintained. This is because the target humidity is maintained at the current tube temperature. In this case, the information on the current liquid pipe temperature may be given to the indoor expansion valve 15 or may not be given. In this case, the process returns to step 301 to continue the control.
The humidity in the room can be adjusted to the target humidity by the control described so far, but the target humidity is not limited to the humidity set by the user. For example, the target humidity may be calculated based on a set temperature set by a user.
Fig. 11 is a control block diagram illustrating second control of the frequency of the compressor 21 and the opening degree of the indoor expansion valve 15. This control calculates an optimum humidity from a set temperature set by a user, and controls the opening degree of the indoor expansion valve 15 so as to attain the optimum humidity.
The control of the room temperature is the same as the example shown in fig. 3. That is, the rotation speed control unit 32 calculates the frequency of the ac power source output by the inverter to drive the motor of the compressor 21, based on the temperature difference between the set temperature and the room temperature detected by the room temperature sensor 13 of the indoor unit 10. The rotation speed control means 32 inputs the frequency obtained by the calculation to the motor of the compressor 21.
Regarding the control of the humidity in the room, the humidity calculation unit 34 calculates the target humidity from the comfort index. The opening degree control means 33 calculates the opening degree of the indoor expansion valve 15 so as to obtain the target humidity obtained by the calculation, and inputs the obtained opening degree information to the indoor expansion valve 15.
The comfort index is an index indicating how comfortable a person is, and as a method of measuring the comfort, for example, a report of average expected thermal sensation (PMV) can be used. The PMV is calculated from 6 elements of temperature, humidity, radiation, airflow, activity amount, and dressing amount, and becomes a function of only temperature and humidity by setting radiation, airflow, activity amount, and dressing amount to constant values. By inputting the set temperature as a temperature so as to have a constant PMV value, the target humidity can be calculated as the optimum humidity.
Further, as a method of measuring comfort, in addition to PMV, a predicted impatient rate (PPD) can be used. PPD is an index indicating what% of people are not satisfied with the environment.
Although the example in which 1 outdoor unit 20 and 1 indoor unit 10 are connected has been described above, as shown in fig. 12, even in the system in which 1 outdoor unit 20 and a plurality of indoor units 10a, \ 8230, and 10n are connected, it is possible to adjust the room temperature to a set temperature and the indoor humidity to a target humidity.
This is because the indoor expansion valves 15a to 15n are provided in the indoor units 10a to 10n, respectively, and therefore the cooling capacities of the indoor units 10a to 10n can be controlled by controlling the indoor expansion valves 15a to 15n, respectively. This makes it possible to perform dehumidification while suppressing the cooling capacity for each of the rooms in which the indoor units 10a to 10n are installed, and to prevent a temperature drop during dehumidification. Further, since it is difficult for the compressor 21 to reach the minimum rotation speed, dehumidification can be performed efficiently even at low load.
The air conditioning system and the control method according to the present invention have been described in detail with reference to the above embodiments, but the present invention is not limited to the above embodiments, and may be modified within the scope of the present invention as can be conceived by those skilled in the art, such as other embodiments, additions, modifications, deletions, and the like.
Description of the reference numerals
10. 10 a-10 n 8230and indoor unit
11. 11 a-11 n 8230and indoor heat exchanger
12. 12 a-12 n 8230and fan
13. 13 a-13 n 8230and room temperature sensor
14. 14 a-14 n 8230and humidity sensor
15. 15 a-15 n 8230and indoor expansion valve
16. 17-8230and tubing temp. sensor
20-8230and outdoor unit
21 \ 8230and compressor
22- (8230); outdoor heat exchanger
23 \ 8230and control device
30. 31 \ 8230and refrigerant piping
32 \ 8230and rotary speed control unit
33 8230a opening control unit
34 method 8230and humidity arithmetic unit
40…CPU
41 \ 8230and flash memory
42…RAM
43 \ 8230and communication I/F
44 8230and I/F control
45 \ 8230and bus
Claims (8)
1. An air conditioning system comprising an indoor unit and an outdoor unit,
the indoor unit includes:
an indoor heat exchanger;
a temperature detection unit that detects a temperature in the room;
a humidity detection unit that detects humidity in the chamber,
the outdoor unit includes:
an outdoor heat exchanger;
a compressor that circulates the refrigerant with the indoor unit,
the air conditioning system includes:
a valve disposed between the outdoor heat exchanger and the indoor heat exchanger;
a rotation speed control unit that controls the rotation speed of the compressor based on the temperature detected by the temperature detection unit;
and an opening control means for controlling the opening of the valve based on the humidity detected by the humidity detection means.
2. The air conditioning system of claim 1,
the opening control unit determines whether to decrease the opening of the valve based on a difference between the humidity detected by the humidity detection unit and a target humidity.
3. The air conditioning system of claim 1,
the indoor unit includes: 2 pipe temperature detection means for detecting the temperature of the outer wall surface of each of the 2 pipes connected to the heat exchanger,
the opening degree control means determines whether or not to increase the degree of superheat of the refrigerant obtained from the 2 pipe temperatures detected by the 2 pipe temperature detection means.
4. The air conditioning system of claim 1,
the indoor unit includes: a pipe temperature detection means for detecting the outer wall surface temperature of 1 of 2 pipes connected to the heat exchanger,
the opening degree control means determines whether or not to lower the temperature of the refrigerant obtained from the piping temperature detected by the piping temperature detection means.
5. The air conditioning system according to any one of claims 1 to 4,
the air conditioning system includes: a calculation unit that calculates a target humidity from the target temperature and an index indicating comfort,
the opening control means controls the opening of the valve based on the humidity detected by the humidity detection means and the target humidity calculated by the calculation means.
6. An air conditioning system including a plurality of indoor units and outdoor units,
each indoor unit includes:
an indoor heat exchanger;
a temperature detection unit that detects a temperature in the room;
a humidity detection unit that detects humidity in the chamber,
the outdoor unit includes:
an outdoor heat exchanger;
a compressor that circulates the refrigerant between the indoor units,
the air conditioning system includes:
a plurality of valves respectively disposed between the respective outdoor heat exchangers and the respective indoor heat exchangers;
a rotation speed control unit that controls the rotation speed of the compressor based on the temperatures detected by the temperature detection units;
and an opening degree control unit that controls the opening degree of each valve based on each humidity detected by each humidity detection unit.
7. A method of controlling operation of an air conditioning system having: an indoor unit including an indoor heat exchanger, a temperature detection unit that detects an indoor temperature, and a humidity detection unit that detects an indoor humidity; an outdoor unit including an outdoor heat exchanger and a compressor for circulating the refrigerant with the indoor unit; a valve disposed between the outdoor heat exchanger and the indoor heat exchanger,
the control method comprises the following steps:
controlling the rotation speed of the compressor based on the temperature detected by the temperature detecting means;
and controlling the opening of the valve based on the humidity detected by the humidity detection means.
8. A method of controlling operation of an air conditioning system, the air conditioning system having: a plurality of indoor units each including an indoor heat exchanger, a temperature detection unit that detects a temperature in a room, and a humidity detection unit that detects a humidity in the room; an outdoor unit including an outdoor heat exchanger and a compressor for circulating the refrigerant between the outdoor heat exchanger and each of the indoor units; a plurality of valves respectively provided between the respective outdoor heat exchangers and the respective indoor heat exchangers,
the control method comprises the following steps:
controlling the rotation speed of the compressor based on the temperatures detected by the temperature detection means;
and controlling the opening degree of each valve based on each humidity detected by each humidity detection means.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/JP2020/017448 WO2021214930A1 (en) | 2020-04-23 | 2020-04-23 | Air-conditioning system and control method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115398158A true CN115398158A (en) | 2022-11-25 |
Family
ID=78270507
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202080099724.XA Pending CN115398158A (en) | 2020-04-23 | 2020-04-23 | Air conditioning system and control method |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPWO2021214930A1 (en) |
| CN (1) | CN115398158A (en) |
| WO (1) | WO2021214930A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11435794B2 (en) * | 2020-07-08 | 2022-09-06 | Nvidia Corporation | Intelligent repurposable cooling systems for mobile datacenter |
| CN115900007B (en) * | 2023-03-09 | 2023-06-23 | 浙江德塔森特数据技术有限公司 | Temperature-adjusting and dehumidifying method and device for rack-mounted air conditioner |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003254583A (en) * | 2002-02-28 | 2003-09-10 | Toshiba Kyaria Kk | Air conditioner |
| JP2006242403A (en) * | 2005-02-28 | 2006-09-14 | Sanyo Electric Co Ltd | Refrigerant cycle device |
| JP2006266677A (en) * | 2006-05-22 | 2006-10-05 | Mitsubishi Electric Corp | Air conditioner |
| JP2012017889A (en) * | 2010-07-07 | 2012-01-26 | Daikin Industries Ltd | Air conditioner |
| JP2017089950A (en) * | 2015-11-06 | 2017-05-25 | 株式会社富士通ゼネラル | Air Conditioning System |
| JP2019168150A (en) * | 2018-03-23 | 2019-10-03 | 株式会社富士通ゼネラル | Air conditioning device |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07294021A (en) * | 1994-04-28 | 1995-11-10 | Kubota Corp | Heat pump type cooling dehumidifying equipment |
| JP3410859B2 (en) * | 1995-06-28 | 2003-05-26 | 東芝キヤリア株式会社 | Air conditioner |
| JP4258117B2 (en) * | 2000-09-29 | 2009-04-30 | 三菱電機株式会社 | Air conditioner |
| JP2003172557A (en) * | 2001-12-06 | 2003-06-20 | Daikin Ind Ltd | Air-conditioner |
| JP6279074B2 (en) * | 2014-05-01 | 2018-02-14 | 三菱電機株式会社 | Air conditioner |
-
2020
- 2020-04-23 WO PCT/JP2020/017448 patent/WO2021214930A1/en active Application Filing
- 2020-04-23 CN CN202080099724.XA patent/CN115398158A/en active Pending
- 2020-04-23 JP JP2022516569A patent/JPWO2021214930A1/ja active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003254583A (en) * | 2002-02-28 | 2003-09-10 | Toshiba Kyaria Kk | Air conditioner |
| JP2006242403A (en) * | 2005-02-28 | 2006-09-14 | Sanyo Electric Co Ltd | Refrigerant cycle device |
| JP2006266677A (en) * | 2006-05-22 | 2006-10-05 | Mitsubishi Electric Corp | Air conditioner |
| JP2012017889A (en) * | 2010-07-07 | 2012-01-26 | Daikin Industries Ltd | Air conditioner |
| JP2017089950A (en) * | 2015-11-06 | 2017-05-25 | 株式会社富士通ゼネラル | Air Conditioning System |
| JP2019168150A (en) * | 2018-03-23 | 2019-10-03 | 株式会社富士通ゼネラル | Air conditioning device |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2021214930A1 (en) | 2021-10-28 |
| JPWO2021214930A1 (en) | 2021-10-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10760798B2 (en) | HVAC unit with hot gas reheat | |
| JP5045524B2 (en) | Refrigeration equipment | |
| EP2261578A1 (en) | Refrigeration device | |
| JP5846226B2 (en) | Air conditioner | |
| JP2015111020A (en) | Air conditioner | |
| JP2018112334A (en) | Air conditioning device | |
| US20180031258A1 (en) | Systems and methods for temperature and humidity control | |
| AU2012392673A1 (en) | Air conditioning apparatus | |
| JPWO2017163296A1 (en) | Refrigeration equipment | |
| JP6897848B2 (en) | Air conditioning system | |
| CN115398158A (en) | Air conditioning system and control method | |
| JP2009243832A (en) | Air conditioner | |
| KR102558826B1 (en) | Air conditioner system and control method | |
| WO2021224962A1 (en) | Air conditioning device | |
| JP7086276B2 (en) | Air conditioner | |
| WO2022024261A1 (en) | Air conditioning device | |
| JP2018185089A (en) | Air conditioner | |
| WO2023105605A1 (en) | Refrigeration cycle device and control method | |
| JP2016102635A (en) | Air conditioner system | |
| JP2023048636A (en) | Air conditioner and control method | |
| CN116294175A (en) | Air conditioning system | |
| JP2000205637A (en) | Air conditioner | |
| JPH028644A (en) | Operation control device for air conditioner |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |