Air conditioning device and air conditioning method

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

[Technical field]

[0001] The present disclosure relates to an air conditioning apparatus and an air conditioning method. [Background technology]

[0002] Conventionally, there is known a multi-type air conditioner that selectively performs an air conditioning operation to adjust the temperature of indoor air and a hot water supply operation to heat water in a hot water storage tank to boil the water and store heat in the hot water storage tank. Some multi-type air conditioners cannot perform air conditioning operation during the period when the hot water supply operation is being performed. In such a multi-type air conditioner, the longer the period during which the hot water supply operation cannot be performed, the longer the period during which the hot water supply operation is performed. If the period during which the hot water supply operation is performed becomes longer, the temperature of the indoor air changes, reducing comfort.

[0003] A technique is known for preventing indoor comfort from being compromised during a hot water supply request issued in a multi-type air conditioner to boil water in response to a decrease in the amount of hot water in the hot water tank. For example, the air conditioner of Patent Document 1 sets an upper limit time for continuing hot water supply operation. If the temperature of the water in the hot water tank does not reach a target temperature even after the upper limit time has elapsed, this air conditioner stops hot water supply operation and returns to cooling operation. When hot water supply operation is stopped, the air conditioner boils the water in the hot water tank by energizing an auxiliary heater provided in the hot water tank. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018-189942 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the air conditioner described in Patent Document 1 starts hot water supply operation using an auxiliary heater when cooling operation is resumed, which causes a problem of increased electricity consumption. In particular, since the auxiliary heater is an electric heater, hot water supply operation using the auxiliary heater consumes more power and has lower operating efficiency than hot water supply operation by the air conditioner, resulting in increased electricity consumption.

[0006] Furthermore, 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 the indoor temperature may differ between the cooling operation and the heating operation. In other words, if the air conditioning load is not the same between the cooling operation and the heating operation, the amount of change in the indoor temperature will differ 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 the hot water supply operation as in the air conditioner of Patent Document 1, there is a risk that indoor comfort will be impaired.

[0007] The present disclosure has been made to solve the problems described above, and aims to provide an air conditioning apparatus and an air conditioning method that can suppress an increase in power consumption and a decrease in indoor comfort, even when the air conditioning apparatus performs hot water supply operation using an auxiliary heater. [Means for solving the problem]

[0008] The air conditioner according to a first aspect includes a heat source machine 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, a hot water supply unit that has a hot water storage tank and performs hot water supply operation by heating with the refrigerant, and a hot water supply unit that responds to heating requests and hot water supply requests. of at the same time Received When the cooling request and the hot water supply request are received, a first alternating operation is performed in which the heating operation and the hot water supply operation are alternately performed. of at the same time Received and 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 cooling operation and the hot water supply operation are not performed, and the control unit performs control so that a first continuous operation time of the hot water supply operation in the first alternating operation is different from a second continuous operation time of the hot water supply operation in the second alternating operation.

[0009] An air conditioning method according to a second aspect is an air conditioning method in an air conditioning apparatus including a heat source unit 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 supply unit that has a hot water storage tank and performs hot water supply operation by heating with the refrigerant, the method including the steps of performing a first alternating 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 simultaneously, and performing a second alternating operation in which the cooling operation and the hot water supply operation are alternately performed when a cooling request and a hot water supply request are output simultaneously, and a first continuous operation time of the hot water supply operation in the first alternating operation is different from a second continuous operation time of the hot water supply operation in the second alternating operation. Effect of the Invention

[0010] According to the present disclosure, even in an air conditioning apparatus that performs hot water supply operation using an auxiliary heater, it is possible to suppress an increase in power consumption and a decrease in indoor comfort. [Brief description of the drawings]

[0011] [Figure 1] 1 is a circuit diagram showing an example of the configuration of an air conditioning device according to an embodiment. [Diagram 2] 2 is a block diagram showing an example of a functional configuration of an air conditioning apparatus according to an embodiment. FIG. [Diagram 3] 5 is a flowchart showing an example of a specific operational procedure performed by the air conditioning apparatus in the embodiment. [Figure 4] FIG. 11 is a diagram for explaining the operation of an air conditioning apparatus in an embodiment, where (a) is a diagram showing the change over time in the operating mode of the heat source unit, (b) is a diagram showing the change over time in the water temperature in the hot water storage tank, and (c) is a diagram showing the change over time in the operation of the electric heater. [Diagram 5] FIG. 4 is a diagram illustrating an example of a relationship between an outside air temperature and a threshold value Tmax(H) in the embodiment. [Figure 6]FIG. 4 is a diagram illustrating an example of a relationship between an outside air temperature and a threshold value Tmax(C) in the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment 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 embodiment, and can be changed as desired within the scope of the technical idea of ​​the present disclosure. In addition, in the following drawings, the scale and number of each structure may be different from the scale and number of the actual structure in order to make each configuration easier to understand.

[0013] (Air Conditioner Configuration) 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 a vapor compression refrigeration cycle operation. The air conditioner is, for example, installed in a general home, but is not limited to this. In the embodiment, the number of air conditioning units is two, but 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 a hydrocarbon, but is not limited to this.

[0014] The heat source unit 100 functions as a heat source machine in an air conditioning system. 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. The pressure sensor 120 and the temperature sensor 122 are provided in the refrigerant piping on the discharge side of the compressor 102. The pressure sensor 120 detects the refrigerant pressure on the discharge side of the compressor 102. The temperature sensors 122, 126, and 124 are provided on the liquid side of the heat source side heat exchanger 106 and measure the refrigerant temperature at the installation location. Note that the temperature sensor for the refrigerant may detect a value equivalent to the refrigerant temperature, such as the temperature of the refrigerant piping, or a value that can be converted to the refrigerant temperature. The temperature sensor 122 detects the temperature of the refrigerant piping on the discharge side of the compressor 102. The temperature sensor 124 detects the temperature of the refrigerant piping 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 the 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.

[0015] The heat source unit 100 is connected to the air conditioning unit 200A via refrigerant pipes 1a and 2a. The heat source unit 100 is connected to the air conditioning unit 200B via refrigerant pipes 1b and 2b. The heat source unit 100 is connected to the 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.

[0016] 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 blower 204 is capable of adjusting the amount of air blown. The air conditioning units 200A and 200B are collectively referred to simply as "air conditioning units 200". The air conditioning units 200A and 200B include temperature sensors 210, 212, and 214. The temperature sensor 210 is provided on the gas side of the heat exchanger 202. The temperature sensor 212 is provided on the liquid side of the heat exchanger 202. The temperature sensors 210 and 212 detect the refrigerant temperature at the installation location. The temperature sensor 214 is provided at the air intake port of the blower 204. The temperature sensor 214 measures the air temperature in a room corresponding to the installation location of the air conditioning units 200A and 200B.

[0017] 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 a refrigerant. The hot water storage tank 304 stores the water to be heat exchanged. The hot water storage tank 304 dispenses hot water from an upper part of the tank in response to a hot water supply request output from the hot water supply control device 308. Low-temperature water is supplied to the hot water storage tank 304 from a lower part of the tank in an amount corresponding to the amount of hot water dispensed. The hot water storage tank 304 is, for example, a tank filled with liquid. The electric heater 306 is a heating unit that heats up in response to the supply of power, thereby heating the water in the hot water storage tank 304. The electric heater 306 functions as an auxiliary heater that assists the hot water supply operation by the heat source unit 100. This allows hot water supply unit 300 to perform a heating operation using electric heater 306. Electric heater 306 functions as a second heat source in the air conditioning system. Temperature sensor 310 is installed in hot water storage tank 304, and measures the temperature of the water in hot water storage tank 304. Temperature sensor 312 is installed on the liquid side of hot water storage tank 304, and detects the refrigerant temperature at the installation location.

[0018] FIG. 2 is a block diagram showing an example of a functional configuration of an air conditioning apparatus according to an 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 an air conditioning request output from the air conditioning controller 400 or a hot water supply request output from the hot water supply controller 500. The heat source control device 112 includes, for example, a measurement unit 112a, a communication unit 112b, a control unit 112c, and a storage unit 112d. The measurement unit 112a receives signals detected by the temperature sensors 122, 124, 126, and 128 and the pressure sensor 120, and performs calculations based on the received signals to measure various temperatures and pressures. The communication unit 112b is connected to each unit in the heat source unit 100 via a communication line, and transmits and receives various data and information. The communication unit 112b receives an air conditioning request output from the air conditioning controller 400 (for example, a remote controller for air conditioning) via the air conditioning control device 206, and supplies the request to the control unit 112c. The air conditioning request is 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 a target temperature in the operation 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, the communication unit 112b communicates the hot water supply request output by the hot water supply controller 500 (hot water supply remote control) via the hot water supply control device 308 and supplies it 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 memory unit 112d stores, for example, the refrigerant temperature of each part in the air conditioning apparatus, the refrigerant pressure of each part in the air conditioning apparatus, air temperatures such as the indoor temperature and the outdoor temperature, operating state quantities such as water temperature, setting values ​​such as the target temperature, and various information on the heat source unit 100.

[0019] The air conditioning control device 206 is a computer realized by, for example, a CPU executing a program. The air conditioning control device 206 controls the air conditioning unit 200 based on an air conditioning request output from the air conditioning controller 400. The air conditioning control device 206 includes, for example, a measurement unit 206a, a control unit 206b, and a communication unit 206c. The measurement unit 206a receives signals detected by the temperature sensors 210, 212, and 214, and performs calculations based on the received signals to measure various temperatures. The communication unit 206c is connected to each unit in the air conditioning unit 200 via a communication line, and transmits and receives various data and information. The communication unit 206c receives the air conditioning request output from the air conditioning controller 400. The control unit 206b controls the blower 204 based on the measured temperatures and the air conditioning request.

[0020] The hot water supply control device 308 is a computer realized by, for example, a CPU executing a program. The hot water supply control device 308 controls the hot water supply unit 300 based on a hot water supply request output from the hot water supply controller 500. The hot water supply control device 308 includes, for example, a measurement unit 308a, a control unit 308b, and a communication unit 308c. The measurement unit 308a receives signals detected by the temperature sensors 310 and 312, and performs calculations based on the received signals to measure various temperatures. The communication unit 308c is connected to each unit in the hot water supply unit 300 via a communication line, 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 it detects that the water temperature in the hot water storage tank 304 has decreased based on the 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 temperature sensor 310 is below 45°C, the control unit 308b outputs a hot water supply request.

[0021] 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 on which application software is installed. The air conditioning controller 400 includes, for example, an input unit 410, a communication unit 420, and a display unit 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 the input results based on the operations and the state of the air conditioning unit 200. The communication unit 420 transmits information based on the operations accepted by the input unit 410 to the air conditioning control device 206 and the heat source control device 112.

[0022] The hot water supply controller 500 is, for example, a remote controller for hot water supply, but is not limited thereto, 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 unit 510, a communication unit 520, and a display unit 530. The 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 the input result based on the operation and the state of the hot water supply unit 300. The communication unit 520 transmits information based on the operation accepted by the input unit 510 to the hot water supply control device 308 and the heat source control device 112.

[0023] 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. In this way, 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.

[0024] The operation modes of the above-mentioned air conditioner will be described below. The air conditioner in the embodiment performs a hot water supply operation mode based on a hot water supply request set by the hot water supply controller 500, a cooling operation mode based on a cooling request set by the air conditioning controller 400, and a heating operation mode based on a heating request set by the air conditioning controller 400. The operation of the air conditioner and the flow state of the refrigerant in each operation mode are described below. When a hot water supply request and a cooling request occur simultaneously, an alternating operation is performed in which the cooling operation and the hot water supply operation are repeated alternately. When the hot water supply request is no longer required, the cooling operation is continued. When a hot water supply request and a heating request occur simultaneously, an alternating operation is performed in which the heating operation and the hot water supply operation are repeated alternately, and when the hot water supply request is no longer required, the heating operation is continued. In principle, the air conditioner performs a hot water supply operation with priority over a cooling operation and a heating operation. The reason for performing a hot water supply operation with priority is to avoid a hot water shortage state in which the hot water storage tank 304 runs out of hot water.

[0025] First, the hot water supply operation will be described. In the hot water supply operation, the heat source control device 112 controls the four-way valve 104 to connect the discharge side of the compressor 102 to the refrigerant pipe 1 and to connect the suction side of the compressor 102 to the gas side of the heat source side heat exchanger 106. The heat source control device 112 also controls the pressure reducing mechanisms 130a and 130b to a closed state (closed path). The high-temperature and high-pressure gas refrigerant discharged from the compressor 102 passes through the four-way valve 104 and the refrigerant pipe 1c, and then flows into the heat exchanger 302. As a result, the gas medium heats the water in the hot water storage tank 304 through the wall surface of the hot water storage tank 304. The refrigerant then flows out of the heat exchanger 302, is depressurized by the pressure reducing mechanism 130c through the refrigerant pipe 2c, and flows into the heat source side heat exchanger 106. As a result, the refrigerant exchanges heat with air (also referred to as 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 passes through the accumulator 110 via the four-way valve 104, and is then sucked back into the compressor 102. Note that in the hot water supply operation, heat exchange may be performed between the refrigerant and a water circuit (not shown), and heat exchange may be performed between the water circuit and water in the hot water storage tank 304.

[0026] 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. The heat source control device 112 also controls the rotation speed of the heat source side blower 108 to be fixed to a set value. Furthermore, the heat source control device 112 controls the opening degree of the pressure reducing mechanism 130c to make the discharge temperature of the pressure reducing mechanism 130c be 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.

[0027] Next, the cooling operation will be described. The heat source control device 112 controls the four-way valve 104 to connect the discharge side of the compressor 102 to the gas side of the heat source side heat exchanger 106, and to connect the suction side of the compressor 102 to the downstream side of the accumulator 110.

[0028] The high-temperature, 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 dissipates heat to the heat source air blown by the heat source side blower 108 to become a high-pressure liquid refrigerant. The high-pressure liquid refrigerant then flows out of the heat source side heat exchanger 106 and is depressurized by the depressurization 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. The low-pressure two-phase refrigerant is then cooled by the indoor air in each heat exchanger 202 to become a low-pressure gas refrigerant. The low-pressure gas refrigerant flows out of the air conditioning units 200A and 200B, respectively, flows into the heat source unit 100 via the refrigerant pipes 1a and 1b, flows into the accumulator 110, and is then sucked into the compressor 102 again.

[0029] In cooling operation, the heat source control device 112 controls the opening of the pressure reducing mechanisms 130a and 130b so that the discharge temperature becomes the set value. The heat source control device 112 also controls the operating frequency of the compressor 102 so that the evaporation temperature becomes the set value. The evaporation temperature is the minimum temperature among the temperatures detected by the temperature sensor 210 and the temperature sensor 212. The heat source control device 112 controls the heat source side blower 108 so that the condensation temperature becomes the set value. The condensation temperature is, for example, the temperature detected by the temperature sensor 126.

[0030] Next, the operating state of the heating operation will be described. The heat source control device 112 controls the four-way valve 104 to connect the discharge side of the compressor 102 to the refrigerant pipe 1 and to connect the suction side of the compressor 102 to the gas side of the heat source side heat exchanger 106.

[0031] The high-temperature, high-pressure gas refrigerant discharged from the compressor 102 passes through the refrigerant pipes 1a and 1b via the four-way valve 104, then flows into the heat exchanger 202, where it heats the indoor air and becomes a high-pressure liquid refrigerant. The high-pressure liquid medium flows out of the air conditioning units 200A and 200B, respectively, is depressurized by the depressurization mechanisms 130a and 130b, respectively, 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 of the heat source side heat exchanger 106 then passes through the accumulator 110 via the four-way valve 104, and is then sucked back into the compressor 102.

[0032] In the heating operation, the heat source control device 112 controls the opening degree 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 the closed state (closed circuit). In addition, the heat source control device 112 controls the operating frequency of the compressor 102 so that the condensing temperature becomes the set value. The condensing temperature is obtained as the maximum temperature among the temperatures detected by the temperature sensor 210 and the temperature sensor 212.

[0033] Next, the boiling operation using electric heater 306 will be described. Electric heater 306 is installed in a state of being submerged inside from the inner wall surface of hot water storage tank 304. Hot water supply unit 300 heats the water in hot water storage tank 304 by energizing electric heater 306. Therefore, the air conditioner can boil hot water by energizing electric heater 306 even when hot water supply operation by heat source unit 100 is not being performed.

[0034] For example, in the case where the hot water supply temperature is set by the hot water supply controller 500 so that it is difficult to complete the hot water supply operation by the heat source unit 100, when the water temperature rises to the set value during the hot water supply operation of the heat source unit 100, the air conditioner starts the hot water supply operation by the electric heater 306. The set value for starting the hot water supply operation by the electric heater 306 is stored in the memory unit 112d. During the hot water supply operation by the electric heater 306, the hot water supply request is output from the hot water supply control device 308 to the heat source control device 112. If an air conditioning request is not output to the heat source control device 112 during the hot water supply operation by the electric heater 306, the heat source unit 100 stops. In contrast, if an air conditioning request is output from any one of the air conditioning units 200A and 200B to the heat source control device 112, the heat source control device 112 resumes the air conditioning operation by the heat source unit 100 even if the hot water supply request is still output. This enables the air conditioning device to quickly resume air conditioning operation, thereby preventing the comfort of the room from being impaired.

[0035] The set value (threshold) at which heating by the electric heater 306 in the hot water supply operation starts is set to, for example, 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, which is close to the maximum allowable refrigerant pressure of the heat source unit 100.

[0036] 3 is a flowchart showing an example of a specific operation procedure by the air conditioner in the embodiment. The air conditioner performs heating operation based on a heating request output from the air conditioning controller 400 (step S10). During heating operation, the water temperature in the hot water storage tank 304 drops, 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 corresponding to the hot water supply request (also referred to as the set hot water supply temperature) 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 hot water supply operation by the heat source unit 100 (step S14).

[0037] The heat source control device 112 judges whether the hot water supply request time by the heat source unit 100 is equal to or less than the maximum continuous hot water supply time (first continuous operation time) when heating is requested (step S16). The maximum continuous hot water supply time when heating is requested is also referred to as the threshold Tmax(H). If the hot water supply operation time by the heat source unit 100 is equal to or less than the threshold Tmax(H) (step S16: YES), the heat source control device 112 judges whether the water temperature in the hot water storage tank 304 is equal to or less than a threshold temperature (for example, 55°C) (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. If the water temperature in the hot water storage tank 304 is equal to the threshold (step S18: YES), the heat source control device 112 returns the process to step S16. If 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 (heating operation) by the electric heater 306 and starts (permits) heating operation by the heat source unit 100 (step S24). If there is no longer a hot water supply request during the heating operation, the heat source control device 112 stops the electric heater 306 and continues the heating operation (step S26).

[0038] In this way, when the water temperature rises due to the hot water supply operation and reaches the threshold temperature, the heat source control device 112 ends the hot water supply operation by the heat source unit 100 and simultaneously starts heating the water by the electric heater 306. This allows the heat source control device 112 to resume 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 heating the water by the electric heater 306 and continues the heating operation.

[0039] According to the air conditioner, since a hot water supply request has priority over an air conditioning request, air conditioning operation cannot be performed while a hot water supply request is being output, but air conditioning operation can be resumed before the water temperature reaches 60° C. As a result, the air conditioner can prevent a decrease in indoor comfort.

[0040] If the hot water supply request 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 resumes the heating operation (step S20). After that, the heat source control device 112 judges 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). If the heating operation time is equal to or less than 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 by the heat source unit 100 and the continuation of the heating operation. 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 resumes the hot water supply operation (step S14).

[0041] In step S18, it is determined whether or not to start the boiling operation by 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 to switch from the hot water supply operation by the heat source unit 100 to the boiling operation by the electric heater 306 when the condensation temperature during the hot water supply operation is equal to or higher than a set value. The set value of the condensation temperature during the hot water supply operation is, for example, 58°C. The condensation 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 outdoor air temperature is low, the refrigerant pressure sucked into the compressor 102 is low, and the condensation temperature becomes lower as the outdoor air temperature is lower, regardless of the water temperature of the hot water storage tank 304. For this reason, by determining 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 a set value, the hot water supply operation by the heat source unit 100 can be continued for a longer period of time. As a result, the air conditioning apparatus can reduce the amount of power consumption required to boil hot water.

[0042] In addition, when the water heating operation by the electric heater 306 is started based on the condensation temperature during hot water supply operation being equal to or higher than the set value in step S18, lowering the rotation frequency of the compressor 102 reduces the heating capacity for the water in the hot water storage tank 304, and the condensation temperature during hot water supply operation becomes lower. If the condensation temperature during hot water supply operation becomes lower, the hot water supply operation period becomes longer, and there is a possibility that the indoor temperature will change and comfort will decrease. The minimum value of the rotation frequency of the compressor 102 during hot water supply operation is set to be higher than the minimum value of the rotation frequency during air conditioning operation. This allows the air conditioner to prevent the period until the condensation temperature during hot water supply operation reaches the set value from becoming longer, and to prevent a decrease in indoor comfort.

[0043] The air conditioner suppresses the decrease in indoor comfort by starting the heating operation by the electric heater 306 and restarting the air conditioning operation at the same time, but if the water temperature in the hot water storage tank 304 is low and the period of hot water supply operation by the heat source unit 100 becomes long, the indoor comfort may decrease. To avoid this, the air conditioner interrupts the hot water supply operation by the heat source unit 100 and resumes the heating operation when the hot water supply operation period by the heat source unit 100 reaches the continuous hot water supply operation time when heating is requested (steps S18, 20). After that, 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 resumes the hot water supply operation by the heat source unit 100. In this way, the air conditioner can suppress the decrease in indoor comfort by alternately repeating the heating operation and the hot water supply operation. However, when the load of the heating operation is high, the rate of change of the indoor temperature during the interruption of the heating operation is high, so the air conditioner can resume the heating operation when the heating operation by the electric heater 306 starts. As a result, the air conditioner can further prevent a decrease in indoor comfort even when the load of air conditioning operation is high.

[0044] 4 is a diagram for explaining the operation of the air conditioner in the embodiment, where (a) is a diagram showing the change over time in the operation mode of the heat source unit 100, (b) is a diagram showing the change over time in the water temperature in the hot water tank 304, and (c) is a diagram showing the change over time in the operation of the electric heater 306. The operation of the air conditioner will be explained together with the processing in FIG. 3 described above.

[0045] The air conditioner suppresses the decrease in indoor comfort by permitting (resuming) heating operation after starting water heating operation by the electric heater 306 (step S24). However, if the rate of increase in water temperature in the electric heater 306 is slow, it takes time to resume hot water supply operation, which decreases the indoor comfort. In response to this, the air conditioner starts hot water supply operation when a hot water supply request is output during heating operation due to a hot water supply request (t1), and continues hot water supply operation until the water temperature in the hot water storage tank 304 reaches the threshold Tmax (H) if the water temperature is 55°C or lower (steps S16, 18). When the hot water supply operation time reaches the threshold Tmax (H) (t2), the hot water supply operation is interrupted and the heating operation is resumed (step S20). After that, if the heating operation time has not reached the threshold THmax, the heating operation is continued (step S22). When the heating operation time reaches the threshold THmax (t3), the heating operation is interrupted and the hot water supply operation is resumed (step S14). By repeating such an operation, the air conditioner can alternate between heating operation and hot water supply operation.

[0046] During alternating operation between heating operation and hot water supply operation, when the water temperature in hot water storage tank 304 reaches 55°C (t4, step S18), electric heater 306 is switched on to start boiling operation and resume heating operation (step S24). When electric heater 306 is switched on, the water temperature in hot water storage tank 304 continues to rise, and when it reaches the set hot water supply temperature of 60°C (t5), the request for hot water supply disappears and heating by electric heater 306 is terminated (step S26). Thereafter, the air conditioner continues heating operation until the request for hot water supply disappears.

[0047] As described above, according to the air conditioner, even if the water temperature does not reach the set hot water temperature during alternating operation between heating operation and hot water supply operation, and the hot water supply operation time becomes long, the heating operation can be resumed by heating with electric heater 306. As a result, the air conditioner can simultaneously prevent the hot water in hot water storage tank 304 from becoming low and prevent a decrease in indoor comfort.

[0048] On the other hand, the air conditioner prohibits heating by electric heater 306 when performing heating operation in the alternating operation between heating operation and hot water supply operation (step S20). The air conditioner prohibits heating by electric heater 306 when performing cooling operation in the alternating operation between cooling operation and hot water supply operation (step S20). This allows the air conditioner to heat water with less power than heating by electric heater 306, and can improve energy saving performance. As a result, the air conditioner can simultaneously prevent the hot water in hot water storage tank 304 from becoming low, prevent a decrease in indoor comfort, and improve energy saving performance.

[0049] In the above-described embodiment, the alternating operation between the heating operation and the hot water supply operation (first alternating operation) is performed, but the "heating request" may be read as the "cooling request", the "heating operation" may be read as the "cooling operation", the "alternating operation between the heating operation and the hot water supply operation" may be read as the "alternating operation between the cooling operation and the hot water supply operation (second alternating operation)", and the "maximum continuous hot water supply time when a heating request is made (threshold Tmax(H))" may be read as the "maximum continuous hot water supply time when a cooling request is made (threshold Tmax(C), second continuous operation time)". In this way, even when a cooling request and a hot water supply request are made simultaneously, the air conditioner can achieve both preventing the hot water in the hot water storage tank 304 from becoming low and preventing a decrease in indoor comfort.

[0050] The continuous operation time of the hot water supply operation in the alternating operation will be described 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 environment in which the air conditioner is installed. For example, if there is a lot of sunlight entering the room in summer and the average outdoor temperature is high, the room temperature will rise faster during periods when cooling operation is interrupted during alternating operation. On the other hand, if the average outdoor temperature is low in winter, the room temperature will fall faster during periods when heating operation is interrupted during alternating operation.

[0051] For this reason, the air conditioner performs control so that the threshold value Tmax(H) in the alternating operation between heating operation and hot water supply operation (steps S14 to S22) is different from the threshold value Tmax(C) in the alternating operation between cooling operation and hot water supply operation (steps S14 to S22). 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, for example, and stores them in the storage unit 112d. When performing heating operation, the air conditioner reads information on the threshold value Tmax(H) from the storage unit 112d in step S16 in FIG. 3, and limits the continuous operation time of hot water supply operation. When performing cooling operation, the air conditioner reads information on the threshold value Tmax(C) from the storage unit 112d in step S16 in FIG. 3, and limits the continuous operation time of hot water supply operation. This allows the air conditioner to adjust the maximum continuous hot water supply time in alternating operation separately for heating operation and cooling operation, based on the installation environment of the air conditioner. As a result, the air conditioner can ensure indoor comfort in both summer and winter.

[0052] If the installation environment in winter (heating season) is assumed to be, for example, an indoor temperature of 20°C and an outdoor temperature of 7°C, the temperature difference between the indoor temperature and the outdoor temperature is 13°C. If the installation environment in summer (cooling season) is assumed to be, for example, an indoor temperature of 27°C and an outdoor temperature of 35°C, the temperature difference between the indoor temperature and the outdoor temperature is 8°C. As such, 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. For this reason, the air conditioner sets the threshold value Tmax(H) shorter than the threshold value Tmax(C). This allows the air conditioner to realize a reduction in indoor comfort during the heating season when the temperature difference between inside and outside is large.

[0053] 5 is a diagram showing an example of the relationship between the outdoor air temperature and the threshold value Tmax(H) in the embodiment. The air conditioner may change the threshold value Tmax(H) based on the outdoor air temperature. The lower the outdoor air temperature, the shorter the threshold value Tmax(H) is set by the air conditioner. This is because the lower the outdoor air temperature, the higher the heating load becomes, and the greater the possibility that the room temperature will drop during hot water supply operation.

[0054] 6 is a diagram showing an example of the relationship between the outdoor air temperature and the threshold value Tmax(C) in an embodiment. The air conditioner may change the threshold value Tmax(C) based on the outdoor air temperature. The higher the outdoor air temperature, the shorter the threshold value Tmax(C) is set by the air conditioner. This is because the higher the outdoor air temperature, the higher the cooling load becomes, and the greater the possibility that the room temperature will rise during hot water supply operation.

[0055] The air conditioner stores in the storage unit 112d the relationship between the outdoor air temperature and the threshold value Tmax(H) shown in Fig. 5 and the relationship between the outdoor air temperature and the threshold value Tmax(C) shown in Fig. 6. This allows the air conditioner to limit the hot water supply operation time in alternating operation to a value corresponding to the detected value of the outdoor air temperature. The threshold value Tmax(H) and the threshold value Tmax(C) for the outdoor air temperature are stored in the storage unit 112d in the heat source control device 112, so that the threshold value Tmax(H) and the threshold value Tmax(C) can be determined for the detected value of the outdoor air temperature. Note that the air conditioner may change both of the threshold value Tmax(H) and the threshold value Tmax(C) based on the outdoor air temperature, but may change at least one of them.

[0056] Specifically, the air conditioning device may store the relationship of the following formula and the coefficients a, b, c, and d. The coefficients a and b are set according to the change in Tmax(H) relative to the outdoor temperature as shown in Fig. 5. The coefficients c and d are set according to the change in Tmax(C) relative to the outdoor temperature as shown in Fig. 6. Tmax(H) = b + a × outside temperature Tmax(C)=dc × Outside temperature By changing the threshold value Tmax(H) and the threshold value Tmax(C) based on the outside air temperature, the air conditioner can set an appropriate hot water supply operation time in response to changes in the air conditioning load.

[0057] In step S22, if the indoor temperature reaches the set temperature during alternating operation, the air conditioner may resume hot water supply operation even if the heating operation time has not reached the maximum continuous air conditioning time. This allows the air conditioner to resume hot water supply operation early without waiting for the maximum continuous air conditioning time to be reached. As a result, the air conditioner can prevent the amount of hot water in the hot water storage tank 304 from becoming low.

[0058] In step S18, the air conditioner determines the timing to start heating with the electric heater 306 based on the water temperature of the hot water tank. Alternatively, the air conditioner may determine the timing to start heating with the electric heater 306 based on the hot water condensation temperature. The hot water condensation temperature is the saturation temperature of the pressure detected by the pressure sensor 120 (high pressure sensor) during hot water supply operation. When the water temperature in the hot water tank 304 rises during hot water supply operation, the hot water condensation temperature also increases. The air conditioner starts heating with the electric heater 306 when the hot water condensation temperature reaches or exceeds the condensation temperature at which heating with the electric heater 306 starts (threshold value, for example, 60°C). Since there is an upper limit to the pressure at which the heat source unit 100 can operate, the air conditioner can continue the hot water supply operation up to the operable range of the heat source unit 100 by determining the start of heating with the electric heater 306 using the hot water condensation temperature. This allows the air conditioner to further reduce power consumption during hot water supply operation.

[0059] Furthermore, in the air conditioner, the minimum frequency of compressor 102 during hot water supply operation from step S14 onwards is set higher than the minimum frequency of compressor 102 during air conditioning operation from step S10 onwards. The air conditioner may set the minimum frequency of compressor 102 during hot water supply operation higher than the minimum frequency of compressor 102 during at least one of cooling operation and heating operation. The operating frequency of compressor 102 becomes higher as the air conditioning load increases. In response to this, the air conditioner sets the minimum operating frequency of compressor 102 to be higher during hot water supply operation than during air conditioning operation, for example, even if the outside air temperature is the same during heating operation and cooling operation.

[0060] If the operating frequency of the compressor 102 is lowered during hot water supply operation, the heating capacity of the boiling water 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 minimum frequency so that the operating frequency of the compressor 102 can be suppressed 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. Furthermore, according to the air conditioner, by raising the hot water supply condensation temperature early, it is possible to start heating by the electric heater 306 early. As a result, according to the air conditioner, it is possible to prevent the amount of hot water in the hot water storage tank 304 from becoming low.

[0061] 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 provides high user satisfaction, even if the installation environment changes with the seasons.

[0062] The above describes in detail the embodiments of the present disclosure with reference to the drawings, but the specific configurations are not limited to the above-described embodiments, and also include designs that do not deviate from the gist of the present disclosure. [Explanation of symbols]

[0063] 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...measurement unit, 112b...communication unit, 112c...control unit, 112d...storage unit, 120...pressure sensor, 122, 124, 126, 128...temperature sensor, 130a, 130b, 130c...pressure reduction mechanism, 200, 200A, 200B...air conditioning unit, 202...heat exchanger, 2 04...blower, 206...air conditioning control device, 206a...measurement 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 unit, 308b...control unit, 308c...communication unit, 310...temperature sensor, 312...temperature sensor, 400...air conditioning controller, 410...input unit, 420...communication unit, 430...display unit, 500...hot water supply controller, 510...input unit, 520...communication unit, 530...display unit

Claims

1. A heat source machine 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; a hot water supply unit including a hot water storage tank and configured to supply hot water by heating with the refrigerant; a control unit that performs a first alternating 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 simultaneously received, and that performs a second alternating operation in which the cooling operation and the hot water supply operation are alternately performed when a cooling request and a hot water supply request are simultaneously received, An air conditioning apparatus, wherein the control unit performs control so that a first continuous operation time of the hot water supply operation in the first alternating operation is different from a second continuous operation time of the hot water supply operation in the second alternating operation.

2. The air conditioning apparatus according to claim 1 , wherein the control unit sets the first continuous operation time to be shorter than the second continuous operation time.

3. The air-conditioning apparatus according to claim 1 , wherein the control unit changes at least one of the first continuous operation time and the second continuous operation time based on an outside air temperature.

4. The hot water supply unit includes a heating unit, The air conditioning apparatus according to claim 1 , wherein the control unit starts heating by the heating unit and starts the heating operation in the first alternating operation, and starts heating by the heating unit and starts the cooling operation in the second alternating operation.

5. 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.

6. The air conditioner according to claim 4 , wherein the control unit starts heating by the heating unit when a condensation temperature of the refrigerant during the hot water supply operation reaches a threshold value.

7. The air conditioning apparatus according to claim 5 or 6, wherein the control unit prohibits the heating unit from starting heating when the heating operation is being performed in the first alternating operation or when the cooling operation is being performed in the second alternating operation.

8. The air conditioning apparatus according to claim 7, wherein the control unit permits heating by the heating unit when the indoor temperature reaches a target temperature while the heating operation is being performed in the first alternating operation or while the cooling operation is being performed in the second alternating operation.

9. The heat source unit has a compressor, The minimum frequency of the compressor in the hot water supply operation is greater 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 greater than the minimum frequency of the compressor in the cooling operation.

3. An air conditioning apparatus according to claim 1 or 2.

10. An air conditioning method for an air conditioner including a heat source machine including a refrigerant cycle that circulates a refrigerant, an air conditioning unit that performs heating operation and cooling operation by heat exchange between the refrigerant and indoor air, and a hot water supply unit that includes a hot water storage tank and performs hot water supply operation by heating with the refrigerant, performing a first alternating 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 simultaneously; and performing a second alternating operation in which the cooling operation and the hot water supply operation are alternately performed when a cooling request and the hot water supply request are output simultaneously, An air conditioning method, wherein a first continuous operation time of the hot water supply operation in the first alternating operation is different from a second continuous operation time of the hot water supply operation in the second alternating operation.

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