WO2023203745A1

WO2023203745A1 - Air-conditioning apparatus and air-conditioning method

Info

Publication number: WO2023203745A1
Application number: PCT/JP2022/018516
Authority: WO
Inventors: 章吾玉木
Original assignee: 三菱電機株式会社
Priority date: 2022-04-22
Filing date: 2022-04-22
Publication date: 2023-10-26

Abstract

An air-conditioning apparatus according to a first embodiment comprises: a heat source device including a refrigerant cycle in which refrigerant is circulated; an air-conditioning unit for performing heat exchange between the refrigerant and indoor air to thereby carry out a warming operation and a cooling operation; a hot-water supply unit provided with a hot-water retention tank, the hot-water supply unit carrying out a hot-water supply operation through heating caused by the refrigerant; and a controller for carrying out a first alternation operation for alternating between the warming operation and the hot-water supply operation when a warming request and a hot-water supply request are outputted simultaneously, and carrying out a second alternation operation for alternating between the cooling operation and the hot-water supply operation when a cooling request and a hot-water supply request are outputted simultaneously. The controller performs control such that a first continuous operation time for the hot-water supply operation in the first alternation operation and a second continuous operation time for the hot-water supply operation in the second alternation operation are different from one another.

Description

Air conditioner and air conditioning method

The present disclosure relates to an air conditioner and an air conditioning method.

Conventionally, multi-type air conditioners are known that selectively perform air conditioning operation that adjusts the temperature of indoor air and hot water supply operation that stores heat in the hot water storage tank by heating water in the hot water storage tank and boiling the water. . Some multi-type air conditioners cannot perform air conditioning operation during the period when hot water supply operation is performed. In such a multi-type air conditioner, the longer the period in which the hot water supply operation cannot be performed, the longer the period in which the hot water supply operation is performed. If the hot water supply operation is carried out for a long period of time, the temperature of the indoor air changes, which impairs comfort.

Even if a hot water supply request to boil water is generated in response to a decrease in the amount of hot water in the hot water storage tank in a multi-type air conditioner, a technology is known to prevent indoor comfort from being impaired during the hot water supply request. There is. For example, the air conditioner disclosed in Patent Document 1 sets an upper limit time for continuing hot water supply operation. This air conditioner stops the hot water supply operation and returns to the cooling operation when the temperature of the water in the hot water storage tank does not reach the target temperature even after the upper limit time has passed. When the hot water supply operation is stopped, the air conditioner boils water in the hot water storage tank by energizing an auxiliary heater provided in the hot water tank.

International Publication No. 2018-189942

However, the air conditioner described in Patent Document 1 starts hot water supply operation using the auxiliary heater in response to returning to cooling operation, so there is a problem that the amount of electricity used increases. In particular, since the auxiliary heater is an electric heater, hot water supply operation using the auxiliary heater consumes more power than hot water supply operation using an air conditioner and has lower operating efficiency, resulting in an increase in electricity consumption.

Further, even if the interruption time of the air conditioning operation is limited to the upper limit time by setting an upper limit time for the hot water supply operation as in Patent Document 1, the amount of change in indoor temperature may differ between the cooling operation and the heating operation. That is, if the air conditioning load is not the same between the cooling operation and the heating operation, the amount of change in indoor temperature will be different between the cooling operation and the heating operation even if the interruption time is the same between the cooling operation and the heating operation. Therefore, even if an upper limit time is set for hot water supply operation as in the air conditioner of Patent Document 1, indoor comfort may be impaired.

The present disclosure was made in order to solve the above-mentioned problems, and even in an air conditioner that uses an auxiliary heater to supply hot water, it suppresses an increase in power consumption and suppresses a decrease in indoor comfort. An object of the present invention is to provide an air conditioning device and an air conditioning method that can perform the following steps.

An air conditioner according to a first aspect includes a heat source device including a refrigerant cycle that circulates a refrigerant, an air conditioning unit that performs heating operation and cooling operation by exchanging heat between the refrigerant and indoor air, and a hot water storage tank, The hot water supply unit performs a hot water supply operation by heating with the refrigerant, and when a heating request and a hot water supply request are output at the same time, a first alternate operation is performed in which the heating operation and the hot water supply operation are alternately performed, and a cooling request and a first alternate operation are performed. a control unit that performs a second alternating operation in which the cooling operation and the hot water supply operation are alternately performed when the hot water supply request is output at the same time; Control is performed so that the first continuous operation time of the hot water supply operation is different from the second continuous operation time of the hot water supply operation in the second alternate operation.

The air conditioning method according to the second aspect includes a heat source device including a refrigerant cycle that circulates a refrigerant, an air conditioning unit that performs heating operation and cooling operation by exchanging heat between the refrigerant and indoor air, and a hot water storage tank, An air conditioning method in an air conditioner, comprising: a hot water supply unit that performs a hot water supply operation by heating with the refrigerant, the heating operation and the hot water supply operation being alternately performed when a heating request and a hot water supply request are output at the same time. and a step of performing a second alternate operation in which the cooling operation and the hot water supply operation are alternately performed when the cooling request and the hot water supply request are output at the same time. However, the first continuous operation time of the hot water supply operation in the first alternate operation is different from the second continuous operation time of the hot water supply operation in the second alternate operation.

According to the present disclosure, even in an air conditioner that performs hot water supply operation using an auxiliary heater, it is possible to suppress an increase in power consumption and to suppress a decrease in indoor comfort.

FIG. 1 is a circuit diagram showing an example of the configuration of an air conditioner according to an embodiment. FIG. 1 is a block diagram showing an example of a functional configuration of an air conditioner according to an embodiment. It is a flowchart which shows an example of the specific operation procedure by the air conditioner in embodiment. FIG. 3 is a diagram for explaining the operation of the air conditioner according to the embodiment, in which (a) is a diagram showing a temporal change in the operation mode of a heat source unit, and (b) is a diagram showing a temporal change in water temperature in a hot water storage tank. (c) is a diagram showing changes in the operation of the electric heater over time. It is a figure showing an example of the relationship between outside temperature and threshold value Tmax (H) in an embodiment. It is a figure showing an example of the relationship between outside temperature and threshold value Tmax (C) in an embodiment.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the scope of the present disclosure is not limited to the following embodiments, and can be arbitrarily modified within the scope of the technical idea of the present disclosure. Further, in the following drawings, in order to make each structure easier to understand, the scale and number of each structure may be different from the scale and number of the actual structure.

(Configuration of air conditioner)
FIG. 1 is a circuit diagram showing an example of the configuration of an air conditioner according to an embodiment. The air conditioner includes, for example, a heat source unit 100,

air conditioning units

200A and 200B, a hot water supply unit 300, an air conditioning controller 400, and a hot water supply controller 500. The air conditioner is, for example, a multi-type air conditioner that performs hot water supply operation, cooling operation, and heating operation by performing vapor compression type refrigeration cycle operation. The air conditioner is installed, for example, in a general home, but is not limited thereto. Although the number of air conditioning units is two in the embodiment, the number is not limited to this, and may be one or three or more. The refrigerant in the air conditioner may be, for example, a natural refrigerant such as R410A, R32, HFO-1234yf, or hydrocarbon, but is not limited thereto.

The heat source unit 100 functions as a heat source machine in an air conditioner. The heat source unit 100 includes, for example, a compressor 102, a four-way valve 104, a heat source side heat exchanger 106, a heat source side blower 108, an accumulator 110, and a heat source control device 112. The heat source unit 100 includes, for example, a pressure sensor 120 and

temperature sensors

122, 124, 126, and 128. A pressure sensor 120 and a temperature sensor 122 are provided in a refrigerant pipe on the discharge side of the compressor 102. Pressure sensor 120 detects refrigerant pressure on the discharge side of compressor 102. A temperature sensor 122, a temperature sensor 126, and a temperature sensor 124 are provided on the liquid side of the heat source side heat exchanger 106 to measure the refrigerant temperature at the installation location. Note that the temperature sensor for the refrigerant only needs to be able to detect a value that corresponds to the refrigerant temperature, such as the temperature of the refrigerant pipe, or a value that can be converted to the refrigerant temperature. The temperature sensor 122 detects the temperature of the refrigerant pipe on the discharge side of the compressor 102. The temperature sensor 124 detects the temperature of the refrigerant pipe near the heat source side heat exchanger 106. The temperature sensor 126 detects the temperature of the refrigerant piping in the heat source side heat exchanger 106. The temperature detected by temperature sensor 126 corresponds to the condensation temperature. The temperature sensor 128 detects the temperature of the air blown by the heat source side blower 108.

The heat source unit 100 is connected to the air conditioning unit 200A via

refrigerant pipes

1a and 2a. Heat source unit 100 is connected to air conditioning unit 200B via

refrigerant pipes

1b and 2b. Heat source unit 100 is connected to hot water supply unit 300 via

refrigerant pipes

1c and 2c. A pressure reducing mechanism 130a is provided in the refrigerant pipe 2a. A pressure reducing mechanism 130b is provided in the refrigerant pipe 2b. A pressure reducing mechanism 130c is provided in the refrigerant pipe 2c.

The

air conditioning units

200A and 200B include, for example, a heat exchanger 202, a blower 204, and an air conditioning control device 206. The air blowing amount of the blower 204 can be adjusted. When the

air conditioning units

200A and 200B are collectively referred to, they are simply referred to as "air conditioning unit 200."

Air conditioning units

200A, 200B are equipped with

temperature sensors

210, 212, 214. Temperature sensor 210 is provided on the gas side of heat exchanger 202. Temperature sensor 212 is provided on the liquid side of heat exchanger 202.

Temperature sensors

210 and 212 detect the refrigerant temperature at the installation location. Temperature sensor 214 is provided at the air intake port of blower 204 . The temperature sensor 214 measures the air temperature in the room corresponding to the installation location of the

air conditioning units

200A, 200B.

The hot water supply unit 300 includes, for example, a heat exchanger 302, a hot water storage tank 304, an electric heater 306, a hot water supply control device 308, and

temperature sensors

310 and 312. The heat exchanger 302 exchanges heat between the water stored in the hot water storage tank 304 and the refrigerant. The hot water storage tank 304 stores water to be heat exchanged. Hot water storage tank 304 dispenses hot water from the top of the tank in response to a hot water supply request output from hot water supply control device 308 . The hot water storage tank 304 is supplied with low-temperature water from the lower part of the tank in an amount equal to the amount of hot water discharged. The hot water storage tank 304 is, for example, a liquid-filled tank. The electric heater 306 is a heating unit that heats water in the hot water storage tank 304 by heating in response to supply of electric power. The electric heater 306 functions as an auxiliary heater that assists the hot water supply operation by the heat source unit 100. Thereby, the hot water supply unit 300 can perform boiling operation using the electric heater 306. Electric heater 306 functions as a second heat source in the air conditioner. Temperature sensor 310 is installed in hot water storage tank 304 and measures the temperature of the water in hot water storage tank 304 . The temperature sensor 312 is installed on the liquid side of the hot water storage tank 304 and detects the refrigerant temperature at the installation location.

FIG. 2 is a block diagram showing an example of the functional configuration of the air conditioner according to the embodiment.
The heat source control device 112 is a computer realized by, for example, a CPU (Central Processing Unit) executing a program. The heat source control device 112 controls the heat source unit 100 based on the air conditioning request output from the air conditioning controller 400 or the hot water supply request output from the hot water supply controller 500. The heat source control device 112 includes, for example, a measurement section 112a, a communication section 112b, a control section 112c, and a storage section 112d. The measurement unit 112a measures various temperatures and pressures by inputting signals detected by the

temperature sensors

122, 124, 126, 128 and the pressure sensor 120, and performing calculations based on the input signals. The communication section 112b is connected to each section of the heat source unit 100 via communication lines, and transmits and receives various data and information. The communication unit 112b inputs an air conditioning request output from the air conditioning controller 400 (for example, an air conditioning remote controller) via the air conditioning control device 206, and supplies it to the control unit 112c. The air conditioning request is, for example, information indicating the operation mode of the air conditioner, such as a cooling request and a heating request. The air conditioning request may include information indicating the target temperature in the operating mode. The communication unit 112b inputs the hot water supply request output from the hot water supply controller 500 and supplies it to the control unit 112c. Alternatively, a hot water supply request output from the hot water supply controller 500 (remote controller for hot water supply) is communicated via the hot water supply control device 308 and supplied to the control unit 112c. The control unit 112c controls the compressor 102, the four-way valve 104, the

pressure reducing mechanisms

130a, 130b, 130c, and the heat source side blower 108 based on the measured temperature and pressure, the air conditioning request, and the hot water supply request. The storage unit 112d includes a semiconductor memory and the like. The storage unit 112d stores, for example, the refrigerant temperature of each part in the air conditioner, the refrigerant pressure of each part in the air conditioner, air temperatures such as indoor temperature and outside temperature, operating state quantities such as water temperature, set values such as target temperature, It stores various information on the heat source unit 100.

The air conditioning control device 206 is, for example, a computer realized by a CPU executing a program. The air conditioning control device 206 controls the air conditioning unit 200 based on the air conditioning request output from the air conditioning controller 400. The air conditioning control device 206 includes, for example, a measurement section 206a, a control section 206b, and a communication section 206c. The measurement unit 206a measures various temperatures by inputting signals detected by the

temperature sensors

210, 212, and 214 and performing calculations based on the input signals. The communication section 206c is connected to each section of the air conditioning unit 200 via communication lines, and transmits and receives various data and information. The communication unit 206c receives an air conditioning request output from the air conditioning controller 400. The control unit 206b controls the blower 204 based on the measured temperature and the air conditioning request.

The hot water supply control device 308 is, for example, a computer realized by a CPU executing a program. Hot water supply control device 308 controls hot water supply unit 300 based on the hot water supply request output from hot water supply controller 500. The hot water supply control device 308 includes, for example, a measurement section 308a, a control section 308b, and a communication section 308c. The measurement unit 308a measures various temperatures by inputting signals detected by the

temperature sensors

310 and 312 and performing calculations based on the input signals. The communication section 308c is connected to each section of the hot water supply unit 300 via communication lines, and transmits and receives various data and information. The communication unit 308c receives a hot water supply request output from the hot water supply controller 500. The control unit 308b controls the electric heater 306 based on the measured temperature and the hot water supply request. Specifically, the control unit 308b outputs a hot water supply request when detecting that the water temperature in the hot water storage tank 304 has become low based on information output from the hot water supply controller 500. For example, when the hot water supply setting temperature is set to 55°C and the water temperature based on the detection signal from the temperature sensor 310 becomes 45°C or less, resulting in a water temperature that is 10°C lower than the hot water supply setting temperature, the control unit 308b Output the request.

The air conditioning controller 400 is, for example, a remote controller for air conditioning, but is not limited to this, and may be a tablet, a personal computer, or a smartphone with application software installed. The air conditioning controller 400 includes, for example, an input section 410, a communication section 420, and a display section 430. The input unit 410 is an operation interface that accepts user operations. The display unit 430 displays various information related to air conditioning, such as input results based on operations and the status of the air conditioning unit 200. The communication unit 420 transmits information based on the operation received by the input unit 410 to the air conditioning control device 206 and the heat source control device 112.

The hot water supply controller 500 is, for example, a remote controller for hot water supply, but is not limited to this, and may be a tablet, a personal computer, or a smartphone on which application software is installed. The hot water supply controller 500 includes, for example, an input section 510, a communication section 520, and a display section 530. Input unit 510 is an operation interface that accepts user operations. The display unit 530 displays various information related to hot water supply, such as input results based on operations and the status of the hot water supply unit 300. Communication unit 520 transmits information based on the operation received by input unit 510 to hot water supply control device 308 and heat source control device 112.

The air conditioner supplies the cooling request or heating request selected by the

air conditioning units

200A and 200B to the heat source control device 112, and supplies the hot water supply request of the hot water supply unit 300 to the heat source control device 112. Thereby, the air conditioner controls each part of the heat source unit 100, the air conditioning unit 200, and the hot water supply unit 300 by the heat source control device 112.

Hereinafter, the operation mode of the air conditioner mentioned above will be explained.
The air conditioner in the embodiment operates in a hot water supply operation mode according to a hot water supply request set by the hot water supply controller 500, a cooling operation mode according to a cooling request set by the air conditioning controller 400, and a heating request set by the air conditioning controller 400. Implement heating operation mode. The operation of the air conditioner and the flow state of the refrigerant in each operation mode will be described below. Note that when a hot water supply request and a cooling request occur at the same time, an alternate operation is performed in which the cooling operation and the hot water supply operation are alternately repeated. Cooling operation continues when there is no longer a demand for hot water supply. When a hot water supply request and a heating request occur at the same time, an alternate operation is performed in which the heating operation and the hot water supply operation are alternately repeated, and when the hot water supply request disappears, the heating operation is continued. In principle, an air conditioner performs hot water supply operation with priority over cooling operation and heating operation. The reason why the hot water supply operation is performed with priority is to avoid the occurrence of a hot water shortage condition in which the hot water storage tank 304 runs out of hot water.

First, the hot water supply operation will be explained. During hot water supply operation, the heat source control device 112 connects the discharge side of the compressor 102 and the refrigerant pipe 1 by controlling the four-way valve 104, and connects the suction side of the compressor 102 and the gas side of the heat source side heat exchanger 106. connect with. Furthermore, the heat source control device 112 controls the

pressure reducing mechanisms

130a and 130b to be in a closed state (closed circuit). The high temperature and high pressure gas refrigerant discharged from the compressor 102 flows into the heat exchanger 302 after passing through the refrigerant pipe 1c via the four-way valve 104. Thereby, the gas medium heats the water in the hot water storage tank 304 via the wall surface of the hot water storage tank 304. Thereafter, the refrigerant flows out of the heat exchanger 302, is depressurized by the pressure reduction mechanism 130c via the refrigerant pipe 2c, and flows into the heat source side heat exchanger 106. Thereby, the refrigerant becomes a low-pressure gas refrigerant by exchanging heat with the air (also referred to as heat source air) supplied by the heat source side blower 108. The low-pressure gas refrigerant flowing out of the heat source side heat exchanger 106 passes through the four-way valve 104 and the accumulator 110, and then is sucked into the compressor 102 again. Note that in the hot water supply operation, heat may be exchanged between the refrigerant and a water circuit (not shown), and heat may be exchanged between the water circuit and the water in the hot water storage tank 304.

In the hot water supply operation, the heat source control device 112 controls the operating frequency of the compressor 102 to be the maximum frequency. Furthermore, the heat source control device 112 controls the rotation speed of the heat source side blower 108 to be fixed at a set value. Further, the heat source control device 112 controls the opening degree of the pressure reducing mechanism 130c so that the discharge temperature of the pressure reducing mechanism 130c becomes a set value. The set value of the discharge temperature is, for example, the saturation temperature of the temperature sensor 122 provided on the discharge side of the compressor 102.

Next, the cooling operation will be explained. The heat source control device 112 connects the discharge side of the compressor 102 and the gas side of the heat source side heat exchanger 106 by controlling the four-way valve 104, and connects the suction side of the compressor 102 and the downstream side of the accumulator 110. let

The high temperature and high pressure gas refrigerant discharged from the compressor 102 flows into the heat source side heat exchanger 106 via the four-way valve 104, and radiates heat to the heat source air blown by the heat source side blower 108, thereby converting the high pressure liquid refrigerant into high temperature liquid refrigerant. becomes. Thereafter, the high-pressure liquid refrigerant flows out from the heat source side heat exchanger 106, and is reduced in pressure by the

pressure reduction mechanisms

130a and 130b to become a low-pressure two-phase refrigerant. The low-pressure two-phase refrigerant flows out of the heat source unit 100 and flows into the

air conditioning units

200A and 200B via the refrigerant pipes 7a and 7b. Thereafter, the low-pressure two-phase refrigerant is cooled by indoor air in each heat exchanger 202 and becomes a low-pressure gas refrigerant. The low-pressure gas refrigerant flows out from the

air conditioning units

200A and 200B, flows into the heat source unit 100 via the

refrigerant pipes

1a and 1b, flows into the accumulator 110, and is sucked into the compressor 102 again.

In the cooling operation, the heat source control device 112 controls the opening degrees of the

pressure reducing mechanisms

130a and 130b so that the discharge temperature becomes the set value. Furthermore, the heat source control device 112 controls the operating frequency of the compressor 102 so that the evaporation temperature becomes a set value. The evaporation temperature is the minimum temperature between the temperature detected by temperature sensor 210 and the temperature detected by temperature sensor 212. The heat source control device 112 controls the heat source side blower 108 so that the condensation temperature becomes a set value. The condensation temperature is, for example, the temperature detected by the temperature sensor 126.

Next, the operating state of the heating operation will be explained. The heat source control device 112 connects the discharge side of the compressor 102 and the refrigerant pipe 1 and connects the suction side of the compressor 102 and the gas side of the heat source side heat exchanger 106 by controlling the four-way valve 104. .

The high-temperature and high-pressure gas refrigerant discharged from the compressor 102 passes through the four-way valve 104 and the

refrigerant pipes

1a and 1b, and then flows into the heat exchanger 202, where it heats indoor air and becomes a high-pressure liquid refrigerant. . The high-pressure liquid medium flows out from the

air conditioning units

200A and 200B, is reduced in pressure by the

pressure reduction mechanisms

130a and 130b, and flows into the heat source side heat exchanger 106. The high-pressure liquid medium exchanges heat with the heat source air supplied by the heat source side blower 108 and becomes a low-pressure gas refrigerant. The low-pressure gas refrigerant flowing out from the heat source side heat exchanger 106 then passes through the four-way valve 104 and the accumulator 110, and then is sucked into the compressor 102 again.

In the heating operation, the heat source control device 112 controls the opening degrees of the

pressure reducing mechanisms

130a and 130b so that the discharge temperature becomes the set value, and controls the pressure reducing mechanism 130c to be in a closed state (closed path). Further, the heat source control device 112 controls the operating frequency of the compressor 102 so that the condensing temperature becomes a set value. The condensation temperature is determined as the maximum temperature between the temperature detected by temperature sensor 210 and the temperature detected by temperature sensor 212.

Next, the boiling operation using the electric heater 306 will be explained. The electric heater 306 is installed so as to be submerged inward from the inner wall surface of the hot water storage tank 304 . Hot water supply unit 300 heats water in hot water storage tank 304 by energizing electric heater 306 . Therefore, the air conditioner can boil water by energizing the electric heater 306 even when the heat source unit 100 is not performing hot water supply operation.

For example, in the case where the hot water supply controller 500 has set a hot water temperature that is such that it is difficult to complete boiling in the hot water supply operation by the heat source unit 100, the air conditioner is configured such that the water temperature rises to the set value during the hot water supply operation of the heat source unit 100. In this case, boiling operation using the electric heater 306 is started. The setting value for starting the boiling operation by the electric heater 306 is stored in the storage unit 112d. While the electric heater 306 is in the boiling operation, the hot water supply request from the hot water supply control device 308 to the heat source control device 112 continues to be output. If no air conditioning request is output to the heat source control device 112 during the heating operation by the electric heater 306, the heat source unit 100 stops. On the other hand, if an air conditioning request is being output from either one of the

air conditioning units

200A and 200B to the heat source control device 112, the heat source control device 112 will be able to Restart air conditioning operation. As a result, the air conditioner can quickly resume air conditioning operation, so that indoor comfort can be prevented from being impaired.

Note that the set value (threshold value) for starting heating by the electric heater 306 during hot water supply operation is set, for example, to 55°C. This is because when R32 or R410A is used as the refrigerant gas, when the boiling temperature reaches 55° C., the refrigerant pressure approaches 4.0 MPaG and approaches the maximum allowable refrigerant pressure of the heat source unit 100.

FIG. 3 is a flowchart illustrating an example of a specific operation procedure by the air conditioner according to the embodiment. The air conditioner performs heating operation based on the heating request output from the air conditioning controller 400 (step S10). During the heating operation, the water temperature in the hot water storage tank 304 decreases, and a hot water supply request is output from the hot water supply control device 308 to the heat source control device 112 (step S12). The set value of the hot water supply temperature (also referred to as set hot water supply temperature) corresponding to the hot water supply request is, for example, 60°C. In response to receiving the hot water supply request, the heat source control device 112 interrupts the heating operation and starts the hot water supply operation by the heat source unit 100 (step S14).

The heat source control device 112 determines whether the hot water supply request time by the heat source unit 100 is less than or equal to the maximum hot water supply continuous time (first continuous operation time) at the time of heating request (step S16). Note that the maximum continuous hot water supply time at the time of a heating request is also described as a threshold value Tmax (H). When the hot water supply operation time by the heat source unit 100 is equal to or less than the threshold value Tmax (H) (step S16: YES), the heat source control device 112 determines whether the water temperature in the hot water storage tank 304 is equal to or less than the threshold temperature (for example, 55° C.). Determination is made (step S18). The threshold temperature of the water temperature is, for example, 55°C, which is lower than the set hot water supply temperature of 60°C. The difference between the threshold temperature and the set hot water supply temperature is the temperature range to be increased by heating by the electric heater 306, and may be any range. When the water temperature in the hot water storage tank 304 is the threshold value (step S18: YES), the heat source control device 112 returns the process to step S16. When the water temperature in the hot water storage tank 304 is not the threshold value (step S18: NO), the heat source control device 112 starts heating (boiling operation) by the electric heater 306, and starts (permits) heating operation by the heat source unit 100 ( Step S24). The heat source control device 112 stops the electric heater 306 and continues the heating operation when there is no longer a request for hot water supply during the heating operation (step S26).

In this manner, the heat source control device 112 ends the hot water supply operation by the heat source unit 100 and simultaneously starts boiling by the electric heater 306 when the water temperature rises due to the hot water supply operation and the water temperature reaches the threshold temperature. Thereby, the heat source control device 112 can restart the heating operation by the heat source unit 100. Thereafter, when the water temperature in the hot water storage tank 304 reaches the set hot water supply temperature and there is no longer a request for hot water supply, the air conditioner ends boiling by the electric heater 306 and continues the heating operation.

According to the air conditioner, hot water supply requests are prioritized over air conditioning requests, so air conditioning cannot be performed during the period when hot water requests are being output, but air conditioning will resume before the water temperature reaches 60°C. be able to. As a result, the air conditioner can suppress a decrease in indoor comfort.

If the requested hot water supply time by the heat source unit 100 is not equal to or less than the threshold Tmax (H) (step S16: NO), the heat source control device 112 interrupts the hot water supply operation by the heat source unit 100 and restarts the heating operation (step S20). After that, the heat source control device 112 determines whether the heating operation time by the heat source unit 100 is equal to or less than the maximum continuous air conditioning time (step S22). When the heating operation time is less than or equal to the maximum continuous air conditioning time at the time of the hot water supply request (step S22: YES), the heat source control device 112 maintains the interruption of the hot water supply operation and the continuation of the heating operation by the heat source unit 100. If the heating operation time is not equal to or less than the maximum continuous air conditioning time at the time of the hot water supply request (step S22: NO), the heat source control device 112 interrupts the heating operation and restarts the hot water supply operation (step S14).

Note that in step S18, it is determined whether or not to start the boiling operation using the electric heater 306 based on the water temperature in the hot water storage tank 304, but the present invention is not limited to this. The air conditioner may determine whether to switch from the hot water supply operation using the heat source unit 100 to the boiling operation using the electric heater 306 when the condensation temperature during the hot water supply operation becomes equal to or higher than a set value. The set value of the condensing temperature during hot water supply operation is, for example, 58°C. The condensing temperature during the hot water supply operation is the saturation temperature at the pressure detected by the pressure sensor 120 (high pressure sensor) during the hot water supply operation. When the outside air temperature is low, the pressure of the refrigerant sucked into the compressor 102 becomes low, and the lower the outside air temperature is, the lower the condensation temperature becomes, regardless of the water temperature in the hot water storage tank 304. Therefore, by determining whether to switch from the hot water supply operation by the heat source unit 100 to the boiling operation by the electric heater 306 based on whether the condensation temperature during the hot water supply operation exceeds the set value, the heat source unit 100 can be operated for a longer time. hot water supply operation can be continued. As a result, the air conditioner can reduce the amount of power consumed for boiling water.

Note that when the boiling operation by the electric heater 306 is started based on the fact that the condensation temperature during the hot water supply operation becomes equal to or higher than the set value in step S18, when the rotation frequency of the compressor 102 is lowered, the heating capacity for water in the hot water storage tank 304 decreases. is smaller, so the condensation temperature during hot water supply operation becomes lower. If the condensing temperature during hot water supply operation becomes low, the hot water supply operation period becomes longer, and indoor temperature may change, leading to a decrease in comfort. The lowest value of the rotational frequency of the compressor 102 during hot water supply operation is made larger than the lowest value of the rotational frequency during air conditioning operation. Thereby, the air conditioner can suppress the period until the condensation temperature reaches the set value during the hot water supply operation from becoming longer, thereby suppressing a decrease in indoor comfort.

The air conditioner suppresses a decrease in indoor comfort by restarting air conditioning operation at the same time as the electric heater 306 starts boiling operation, but the water temperature in the hot water storage tank 304 is low and the hot water supply operation period by the heat source unit 100 is interrupted. If the time period becomes longer, indoor comfort may decrease. To avoid this, the air conditioner interrupts the hot water supply operation by the heat source unit 100 and restarts the heating operation when the hot water supply operation period by the heat source unit 100 reaches the hot water supply continuous operation time at the time of heating request (step S18 , 20). Thereafter, when the heating operation period reaches the maximum continuous air conditioning time when hot water supply is requested, the air conditioner interrupts the heating operation again and restarts the hot water supply operation by the heat source unit 100. In this way, the air conditioner can suppress a decrease in indoor comfort by alternately repeating heating operation and hot water supply operation. However, when the load of the heating operation is high, the rate of change in indoor temperature during the interruption of the heating operation is high, so that the air conditioner can restart the heating operation when the electric heater 306 starts the heating operation. Thereby, according to the air conditioner, even if the load of air conditioning operation is high, it is possible to further suppress a decrease in indoor comfort.

4A and 4B are diagrams for explaining the operation of the air conditioner according to the embodiment, in which (a) is a diagram showing changes over time in the operation mode of the heat source unit 100, and (b) is a diagram showing the water temperature in the hot water storage tank 304. (c) is a diagram showing a change in the operation of the electric heater 306 over time. The operation of the air conditioner will be explained together with the process in FIG. 3 described above.

The air conditioner suppresses a decrease in indoor comfort by permitting (resuming) the heating operation after starting the heating operation using the electric heater 306 (step S24). However, if the rate of increase in the water temperature in the electric heater 306 is slow, it takes time to restart the hot water supply operation, resulting in a decrease in indoor comfort. On the other hand, the air conditioner starts hot water supply operation when a hot water supply request is output (t1) while performing heating operation due to a hot water supply request, and if the water temperature in the hot water storage tank 304 is 55 degrees Celsius or lower, Then, the hot water supply operation continues until the threshold value Tmax (H) is reached (steps S16 and 18). When the hot water supply operation time reaches the threshold value Tmax (H) (t2), the hot water supply operation is interrupted and the heating operation is restarted (step S20). Thereafter, if the heating operation time has not reached the threshold value THmax, the heating operation is continued (step S22). When the heating operation time reaches the threshold value THmax (t3), the heating operation is interrupted and the hot water supply operation is restarted (step S14). By repeating such operations, the air conditioner can perform alternate operations of heating operation and hot water supply operation.

During the alternating operation between the heating operation and the hot water supply operation, when the water temperature in the hot water storage tank 304 reaches 55° C. (t4, step S18), the electric heater 306 is turned on to start the boiling operation and restart the heating operation. (Step S24). When the electric heater 306 is turned on, the water temperature in the hot water storage tank 304 continues to rise, and when it reaches the set hot water supply temperature of 60° C. (t5), the hot water supply request disappears and heating by the electric heater 306 ends (step S26). Thereafter, the air conditioner continues to perform heating operation until there is no longer a demand for hot water supply.

As described above, according to the air conditioner, even if the water temperature does not reach the set hot water supply temperature even if the heating operation and hot water supply operation are performed alternately, and the hot water supply operation time becomes longer, heating by the electric heater 306 can be performed. Heating operation can be resumed. As a result, the air conditioner can achieve both of suppressing a decrease in hot water in the hot water storage tank 304 and suppressing a decrease in indoor comfort.

On the other hand, the air conditioner prohibits heating by the electric heater 306 when performing the heating operation in the alternating operation of the heating operation and the hot water supply operation (step S20). The air conditioner prohibits heating by the electric heater 306 when performing the cooling operation in the alternating operation between the cooling operation and the hot water supply operation (step S20). As a result, the air conditioner can heat up the air with lower power than heating by the electric heater 306, and can improve energy saving performance. As a result, the air conditioner can simultaneously suppress the amount of hot water in the hot water storage tank 304 from decreasing, suppress a decrease in indoor comfort, and improve energy-saving performance. I can do it.

In the embodiment described above, the heating operation and the hot water supply operation are alternately operated (first alternate operation), but "heating request" is read as "cooling request", "heating operation" is read as "cooling operation", "Alternate operation between heating operation and hot water supply operation" should be read as "alternate operation between cooling operation and hot water supply operation (second alternate operation)", and "maximum continuous hot water supply time when heating is requested (threshold value Tmax (H))" ” may be read as “maximum continuous hot water supply time (threshold value Tmax (C), second continuous operation time) at the time of cooling request”. As a result, the air conditioner can suppress the amount of hot water in the hot water storage tank 304 from decreasing and suppress a decrease in indoor comfort even when a request for air conditioning and a request for hot water supply occur at the same time. It is possible to achieve both.

The continuous operation time of the hot water supply operation in the alternate operation will be explained below.
In an air conditioner, whether the load of heating operation in winter or the load of cooling operation in summer is higher depends on the installation environment of the air conditioner. For example, in the summer when sunlight enters the room well and the average temperature of the outside air is high, the rate of rise in the room temperature increases during the interruption period of the cooling operation in the alternate operation. On the other hand, when the average outside air temperature is low in winter, the rate of decrease in the room temperature increases during the interruption period of the heating operation in the alternate operation.

Therefore, the air conditioner sets the threshold value Tmax (H) in the alternating operation between heating operation and hot water supply operation (step S14 to step S22) and the threshold value Tmax (H) in the alternating operation between cooling operation and hot water supply operation (step S14 to step S22). Control is performed so that Tmax(C) is different. For example, the air conditioner sets the threshold value Tmax(H) and the threshold value Tmax(C) to different times based on the installation environment of the air conditioner, and stores them in the storage unit 112d. When the air conditioner is performing the heating operation, in step S16 in FIG. 3, the air conditioner reads information on the threshold value Tmax (H) from the storage unit 112d, and limits the continuous operation time of the hot water supply operation. When the air conditioner is performing the cooling operation, in step S16 in FIG. 3, the air conditioner reads information on the threshold value Tmax (C) from the storage unit 112d, and limits the continuous operation time of the hot water supply operation. Thereby, the air conditioner can separately adjust the maximum continuous hot water supply time in the alternate operation for the heating operation and the cooling operation based on the installation environment of the air conditioner. As a result, the air conditioner can ensure indoor comfort both in summer and winter.

Assuming that the installation environment in winter (heating season) is, for example, an indoor temperature of 20°C and an outside air temperature of 7°C, the temperature difference between the indoor temperature and the outside air temperature will be 13°C. Assuming that the installation environment in summer (cooling season) is, for example, an indoor temperature of 27°C and an outside air temperature of 35°C, the temperature difference between the indoor temperature and the outside air temperature is 8°C. In this way, since the temperature difference between inside and outside is higher in winter than in summer, the air conditioning load is higher in heating operation than in cooling operation. Therefore, the air conditioner sets the threshold value Tmax(H) shorter than the threshold value Tmax(C). As a result, the air conditioner can reduce indoor comfort during the heating season when there is a large difference in temperature between the inside and outside.

FIG. 5 is a diagram showing an example of the relationship between the outside air temperature and the threshold value Tmax(H) in the embodiment. The air conditioner may change the threshold value Tmax(H) based on the outside temperature. The air conditioner shortens the threshold value Tmax(H) as the outside air temperature decreases. This is because the lower the outside air temperature, the higher the heating load, and the greater the possibility that the room temperature will drop during hot water supply operation.

FIG. 6 is a diagram showing an example of the relationship between the outside air temperature and the threshold value Tmax (C) in the embodiment. The air conditioner may change the threshold value Tmax(C) based on the outside temperature. The air conditioner shortens the threshold value Tmax (C) as the outside temperature increases. This is because the higher the outside air temperature, the higher the cooling load, and the greater the possibility that the room temperature will rise during hot water supply operation.

The air conditioner stores the relationship between the outside air temperature and the threshold value Tmax(H) shown in FIG. 5 and the relationship between the outside air temperature and the threshold value Tmax(C) shown in FIG. 6 in the storage unit 112d. Thereby, the air conditioner can limit the hot water supply operation time in the alternate operation to a value corresponding to the detected value of the outside air temperature. The threshold value Tmax(H) and the threshold value Tmax(C) for the outside air temperature are stored in the storage unit 112d of the heat source control device 112, and the threshold value Tmax(H) and the threshold value Tmax(C) are stored for the detected value of the outside air temperature. ) can be determined. Note that the air conditioner may change both of the threshold value Tmax(H) and the threshold value Tmax(C) based on the outside air temperature, or may change at least one of the threshold values Tmax(H) and Tmax(C).

Specifically, the air conditioner may store the relationships and coefficients a, b, c, and d of the following equations. The coefficients a and b are set based on the change in Tmax (H) with respect to the outside temperature as shown in FIG. The coefficients c and d are set based on the change in Tmax (C) with respect to the outside temperature as shown in FIG.
Tmax (H) = b + a x outside air temperature Tmax (C) = d - c x outside air temperature The air conditioner reduces the air conditioning load by changing the threshold Tmax (H) and the threshold Tmax (C) based on the outside air temperature. Appropriate hot water supply operation time can be set according to the change.

In step S22, if the indoor temperature reaches the set temperature during the alternate operation, the air conditioner may restart the hot water supply operation even if the heating operation time has not reached the maximum continuous air conditioning time. As a result, the air conditioner can restart the hot water supply operation at an early stage without waiting for the maximum continuous air conditioning time to be reached. As a result, the air conditioner can suppress the amount of hot water in the hot water storage tank 304 from decreasing.

In step S18, the air conditioner determines the heating start timing of the electric heater 306 based on the water temperature in the hot water storage tank, but instead of this, the air conditioner determines the heating start timing of the electric heater 306 based on the hot water condensing temperature. good. The hot water supply condensing temperature is the saturation temperature of the pressure detected by the pressure sensor 120 (high pressure sensor) during hot water supply operation. During hot water supply operation, as the water temperature in the hot water storage tank 304 increases, the hot water condensation temperature also increases. The air conditioner starts heating by the electric heater 306 when the hot water condensing temperature becomes equal to or higher than the condensing temperature at which the electric heater 306 starts heating (threshold value, for example, 60° C.). Since there is an upper limit to the operating pressure in the heat source unit 100, the air conditioner uses the hot water supply condensation temperature to determine the start of heating by the electric heater 306, and thereby maintains the hot water supply operation up to the operating range of the heat source unit 100. can be continued. Thereby, the air conditioner can further suppress power consumption during hot water supply operation.

Further, in the air conditioner, the lowest frequency of the compressor 102 during the hot water supply operation after step S14 is set higher than the lowest frequency of the compressor 102 during the air conditioning operation after step S10. In the air conditioner, the lowest frequency of the compressor 102 during the hot water supply operation may be set higher than the lowest frequency of the compressor 102 during at least one of the cooling operation and the heating operation. The operating frequency of the compressor 102 increases as the air conditioning load increases. In contrast, the air conditioner sets the minimum frequency at which the compressor 102 operates to be higher during hot water supply operation than during air conditioning operation, for example, even if the outside temperature is the same during heating operation and cooling operation. do.

If the operating frequency of the compressor 102 is lowered during hot water supply operation, the heating capacity for boiling will be reduced and it will take a long time to complete hot water supply. On the other hand, it is necessary to be able to reduce the lowest frequency so as to suppress the operating frequency of the compressor 102 when the load during air conditioning operation is low. According to the air conditioner, by setting the minimum frequency of the compressor 102 high during hot water supply operation, it is possible to prevent the heating capacity from becoming extremely low. Further, according to the air conditioner, heating by the electric heater 306 can be started early by raising the hot water condensing temperature early. Thereby, according to the air conditioner, it is possible to suppress the amount of hot water in the hot water storage tank 304 from decreasing.

As described above, according to the air conditioner, it is possible to provide a hot water supply air conditioning system that achieves both air conditioning performance and hot water supply performance and has high user satisfaction, even if the installation environment changes with the seasons.

Although the embodiments of the present disclosure have been described above in detail with reference to the drawings, the specific configuration is not limited to the above-described embodiments, and includes designs within the scope of the gist of the present disclosure. It will be done.

1, 1a, 1b, 1c... Refrigerant piping, 2a, 2b, 2c... Refrigerant piping, 7a, 7b... Refrigerant piping, 100... Heat source unit, 102... Compressor, 104... Four-way valve, 106... Heat source side heat exchanger, 108...Heat source side blower, 110...Accumulator, 112...Heat source control device, 112a...Measuring section, 112b...Communication section, 112c...Control section, 112d...Storage section, 120...Pressure sensor, 122, 124, 126, 128...Temperature Sensor, 130a, 130b, 130c...pressure reduction mechanism, 200, 200A, 200B...air conditioning unit, 202...heat exchanger, 204...air blower, 206...air conditioning control device, 206a...measuring unit, 206b...control unit, 206c...communication unit , 210, 212, 214...Temperature sensor, 300...Hot water supply unit, 302...Heat exchanger, 304...Hot water storage tank, 306...Electric heater, 308...Hot water supply control device, 308a...Measurement section, 308b...Control section, 308c...Communication Part, 310...Temperature sensor, 312...Temperature sensor, 400...Air conditioning controller, 410...Input section, 420...Communication section, 430...Display section, 500...Hot water supply controller, 510...Input section, 520...Communication section, 530...Display Department

Claims

a heat source machine including a refrigerant cycle that circulates refrigerant;
an air conditioning unit that performs heating operation and cooling operation by exchanging heat between the refrigerant and indoor air;
a hot water supply unit that includes a hot water storage tank and performs hot water supply operation by heating with the refrigerant;
When a heating request and a hot water supply request are output at the same time, a first alternate operation is performed in which the heating operation and the hot water supply operation are performed alternately, and when a cooling request and the hot water supply request are output at the same time, the cooling operation is performed. and a control unit that performs a second alternate operation that alternately performs the hot water supply operation,
The control unit performs control such that a first continuous operation time of the hot water supply operation in the first alternate operation is different from a second continuous operation time of the hot water supply operation in the second alternate operation. Air conditioner.
The air conditioner according to claim 1, wherein the control unit makes the first continuous operation time shorter than the second continuous operation time.
The air conditioner according to claim 1 or 2, wherein the control unit changes at least one of the first continuous operation time and the second continuous operation time based on outside temperature.
The hot water supply unit includes a heating section,
The control unit causes the heating unit to start heating and starts the heating operation in the first alternate operation, and starts the heating unit to start heating and starts the cooling operation in the second alternate operation. , The air conditioner according to claim 1 or 2.
The air conditioner according to claim 4, wherein the control unit starts heating by the heating unit when the water temperature in the hot water storage tank reaches a threshold value.
The air conditioner according to claim 4, wherein the control unit starts heating by the heating unit when the condensation temperature of the refrigerant during the hot water supply operation reaches a threshold value.
The control unit prohibits the heating unit from starting heating when the heating operation is performed in the first alternate operation or when the cooling operation is performed in the second alternate operation. The air conditioner according to claim 5 or 6.
The control unit is configured to control the control unit when the indoor temperature reaches the target temperature when the heating operation is performed in the first alternate operation or when the cooling operation is performed in the second alternate operation. The air conditioner according to claim 7, which allows heating by the heating section.
The heat source machine has a compressor,
The minimum frequency of the compressor in the hot water supply operation is higher than the minimum frequency of the compressor in the heating operation, and the minimum frequency of the compressor in the hot water supply operation is higher than the minimum frequency of the compressor in the cooling operation. big,
The air conditioner according to claim 1 or 2.
A hot water supply device that includes a heat source device including a refrigerant cycle that circulates a refrigerant, an air conditioning unit that performs heating and cooling operations by exchanging heat between the refrigerant and indoor air, and a hot water storage tank, and that performs hot water supply operation by heating with the refrigerant. An air conditioning method in an air conditioner comprising a unit,
performing a first alternate operation in which the heating operation and the hot water supply operation are alternately performed when a heating request and a hot water supply request are output at the same time;
performing a second alternate operation in which the cooling operation and the hot water supply operation are alternately performed when the cooling request and the hot water supply request are output at the same time;
An air conditioning method, wherein a first continuous operation time of the hot water supply operation in the first alternate operation is different from a second continuous operation time of the hot water supply operation in the second alternate operation.