GB2627390A - Air conditioner - Google Patents

Air conditioner Download PDF

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Publication number
GB2627390A
GB2627390A GB2407342.1A GB202407342A GB2627390A GB 2627390 A GB2627390 A GB 2627390A GB 202407342 A GB202407342 A GB 202407342A GB 2627390 A GB2627390 A GB 2627390A
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GB
United Kingdom
Prior art keywords
heat
refrigerant
medium
heat medium
relay
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
GB2407342.1A
Other versions
GB202407342D0 (en
Inventor
Asanuma Hiroaki
Motomura Yuji
Ikeda Soshi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Publication of GB202407342D0 publication Critical patent/GB202407342D0/en
Publication of GB2627390A publication Critical patent/GB2627390A/en
Pending legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B6/00—Compression machines, plants or systems, with several condenser circuits
    • F25B6/02—Compression machines, plants or systems, with several condenser circuits arranged in parallel
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
    • F24H4/00—Fluid heaters characterised by the use of heat pumps
    • F24H4/02—Water heaters
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B1/00—Compression machines, plants or systems with non-reversible cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B13/00—Compression machines, plants or systems, with reversible cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B7/00—Compression machines, plants or systems, with cascade operation, i.e. with two or more circuits, the heat from the condenser of one circuit being absorbed by the evaporator of the next circuit
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/003—Indoor unit with water as a heat sink or heat source
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/023—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units
    • F25B2313/0233—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units in parallel arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/12—Inflammable refrigerants
    • F25B2400/121—Inflammable refrigerants using R1234

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Heat-Pump Type And Storage Water Heaters (AREA)

Abstract

According to the present invention, an air conditioner comprises outdoor equipment, refrigerant indoor equipment, first intermediate equipment, second intermediate equipment, first heat medium indoor equipment, and a hot water tank. The outdoor equipment includes: a first compressor that circulates a first refrigerant through a first refrigerant circuit; and an outdoor heat exchanger through which the first refrigerant flows. The refrigerant indoor equipment includes a refrigerant heat exchanger through which the first refrigerant flows. The first intermediate equipment includes: a first pump that circulates a heat medium that is different from the first refrigerant through a first heat medium circuit; and a first intermediate heat exchanger that performs a heat exchange between the first refrigerant and the heat medium that circulates through the first heat medium circuit. The second intermediate equipment includes: a second pump that circulates a heat medium that is different from the first refrigerant through a second heat medium circuit; and a second intermediate heat exchanger that performs a heat exchange between the first refrigerant and the heat medium that circulates through the second heat medium circuit. The first heat medium indoor equipment includes a first heat medium heat exchanger through which the heat medium that circulates through the first heat medium circuit flows. The hot water tank stores the heat medium that circulates through the second heat medium circuit.

Description

DESCRIPTION Title of Invention
AIR CONDITIONER
Technical Field
[0001] The present disclosure relates to an air-conditioning apparatus including a hot water storage tank.
Background Art
[0002] In a known exiting air-conditioning apparatus, refrigerant is circulated between an outdoor unit installed outdoors and serving as a heat source unit and an indoor unit installed indoors, heat generated by the outdoor unit is carried to the indoor unit, heat exchange is performed between the refrigerant and water, and water heated thereby is stored in a hot water storage tank. As such an example, Patent Literature 1 discloses a configuration in which water to be stored in a hot water storage tank is highly efficiently heated to a high temperature by a water temperature raising unit using two kinds of refrigerant whose condensing temperatures are different from each other. Citation List Patent Literature [0003] Patent Literature 1: International Publication No. 2012/077156
Summary of Invention
Technical Problem [0004] In general, air-conditioning apparatuses need a pump that delivers heated water to a hot water storage tank. The air-conditioning apparatus of Patent Literature 1 has a pump provided at a pipe connecting a water temperature raising unit and the hot water storage tank. Therefore, in Patent Literature 1, the pump needs to be set at the time of installing the hot water storage tank, thereby increasing the cost of on-site work.
[0005] The present disclosure is applied to solve the above problem and relates to an air-conditioning apparatus in which a pump does not need to be set at an installation time, thereby reducing the cost of on-site work.
Solution to Problem [0006] An air-conditioning apparatus according to an embodiment of the present disclosure includes: an outdoor unit including a first compressor configured to cause first refrigerant to circulate in a first refrigerant circuit and an outdoor heat exchanger through which the first refrigerant flows; a refrigerant indoor unit including a refrigerant heat exchanger through which the first refrigerant flows; a first relay unit including a first pump configured to cause a heat medium differing from the first refrigerant to circulate in a first heat medium circuit and a first relay heat exchanger being configured to cause heat exchange to be performed between the first refrigerant and the heat medium that circulates in the first heat medium circuit; a second relay unit including a second pump configured to cause a heat medium differing from the first refrigerant to circulate in a second heat medium circuit and a second relay heat exchanger configured to cause heat exchange to be performed between the first refrigerant and the heat medium that circulates in the second heat medium circuit; a first heat-medium indoor unit including a first heat-medium heat exchanger through which the heat medium that circulates in the first heat medium circuit flows; and a hot water storage tank in which the heat medium that circulates in the second heat medium circuit is stored.
Advantageous Effects of Invention [0007] In the air-conditioning apparatus according to the embodiment of the present disclosure, the relay units include the pumps. Thus, it is not necessary to provide a pump at a pipe connecting a relay unit and the hot water storage. Therefore, in the air-conditioning apparatus according to the embodiment of the present disclosure, it is not necessary to provide a pump at the time of installing the hot water storage tank, and it is therefore possible to reduce the cost of on-site work.
Brief Description of Drawings
[0008] [Fig. 1] Fig. 1 is a circuit diagram of an air-conditioning apparatus according to Embodiment 1.
[Fig. 2] Fig. 2 is a circuit diagram of an air-conditioning apparatus according to Embodiment 2.
[Fig. 3] Fig. 3 is a circuit diagram of an air-conditioning apparatus according to Embodiment 3.
[Fig. 4] Fig. 4 is a circuit diagram of an air-conditioning apparatus according to Embodiment 4.
[Fig. 5] Fig. 5 is a diagram indicating the operating points of refrigerant circuits according to Embodiment 4 on a P-h diagram.
[Fig. 6] Fig. 6 is a circuit diagram of an air-conditioning apparatus according to Embodiment 5.
[Fig. 7] Fig. 7 is a circuit diagram of an air-conditioning apparatus according to Embodiment 6.
[Fig. 8] Fig. 8 is a circuit diagram of an air-conditioning apparatus according to Embodiment 7.
Description of Embodiments
[0009] The embodiments will be described with reference to the drawings. In each of figures in the drawings, components that are the same as or equivalent to those in a previous figure or previous figures are denoted by the same reference signs. The same is true of the entire text of the specification. Furthermore, configurations of components that are described in in the entire text of the specification are each merely an example, and those descriptions are not limiting. In addition, in the figures, relationships in size between components may be different from actual ones.
[0010] Embodiment 1 Fig. 1 is a circuit diagram of an air-conditioning apparatus according to Embodiment 1. The air-conditioning apparatus 100 of Embodiment 1 conditions air in a plurality of air-conditioned spaces in, for example, a building. As illustrated in Fig. 1, the air-conditioning apparatus 100 includes an outdoor unit 1, a plurality of refrigerant indoor units 2a to 2c, a heat-medium indoor unit 3a, a relay unit 4a connected between the outdoor unit 1 and the heat-medium indoor unit 3a, a hot water storage tank 6, and a relay unit 4b connected between the outdoor unit 1 and the heat-medium indoor unit 3a. The relay units 4a and 4b cause heat exchange to be performed between refrigerant supplied from the outdoor unit 1 and a heat medium. It should be noted that the relay units 4a and 4b correspond to the "first relay unit" and the "second relay unit" of the present disclosure, respectively. Furthermore, the heat-medium indoor unit 3a corresponds to the "first heat-medium indoor unit" of the present disclosure.
[0011] The outdoor unit 1 and the refrigerant indoor units 2a to 2c, as well as the outdoor unit 1 and the relay units 4, are connected to each other by refrigerant pipes 65 and 66 through which the refrigerant flows. The refrigerant indoor unit 2a to 2c and the relay units 4 are connected parallel to the outdoor unit 1. Furthermore, the relay unit 4a and the heat-medium indoor unit 3a are connected by heat medium pipes 71a and 72a through which the heat medium flows. The relay unit 4b and the hot water storage tank 6 are connected by heat medium pipes 73 and 74 through which the heat medium flows. Heat generated in the outdoor unit 1 is carried to the refrigerant indoor units 2a to 2c and the relay units 4a and 4b by the refrigerant that flows though the refrigerant pipes 65 and 66. Heat exchanged in the relay unit 4a is carried to the heat-medium indoor unit 3a by the heat medium that flows through the heat medium pipe 71a.
[0012] The refrigerant indoor units 2a to 2c of the air-conditioning apparatus 100 directly cool or heat the air-conditioned spaces with the refrigerant supplied from the outdoor unit 1. The heat-medium indoor unit 3a cools or heats the air-conditioned spaces with the heat medium to which heat is transferred from the refrigerant supplied from the outdoor unit 1. That is, the air-conditioning apparatus 100 includes both refrigerant indoor units that directly use the refrigerant supplied from the outdoor unit 1 and a heat-medium indoor unit that indirectly uses the refrigerant supplied from the outdoor unit 1. The hot water storage tank 6 stores a heat medium that is heated by the refrigerant supplied from the outdoor unit 1. Although it is not illustrated, a pipe through which the heat medium is supplied from the outside of the air-conditioning apparatus 100 to the hot water storage tank 6 before the heat medium is heated and a pipe through which the heat medium is supplied from the hot water storage tank 6 to a use side after the heat medium is heated are attached to the hot water storage tank 6.
[0013] Refrigerant for use in the air-conditioning apparatus 100 is, for example, a single-component refrigerant such as R32, a near-azeotropic refrigerant mixture such as R410A, refrigerant containing a double bond or CF3I in a chemical formula and having a comparatively small global warming potential or a mixture of those refrigerant or natural refrigerant such as CF3I, CO2, or propane. A heat medium for use in the heat-medium indoor unit 3a is, for example, water, brine (antifreeze), a mixture thereof, or a mixture of water and a highly anticorrosive additive. Furthermore, the heat medium stored in the hot water storage tank 6 is, for example, water. It should be noted that the "heat medium" in the present disclosure is a heat medium other than the refrigerant and is non-toxic and non-flammable.
[0014] The outdoor unit 1 includes a compressor 11, a flow switching valve 12, an outdoor heat exchanger 13, an outdoor fan 14, an accumulator 15, an outdoor refrigerant pipe 16, and an outdoor control device 17. The compressor 11 sucks low-temperature and low-pressure gas refrigerant, compresses the low-temperature and low-pressure gas refrigerant to change it into high-temperature and high-pressure gas refrigerant, and discharges the high-temperature and high-pressure gas refrigerant. The compressor 11 is, for example, an inverter compressor whose capacity can be controlled. It should be noted that the compressor 11 corresponds to the "first compressor" of the present disclosure.
[0015] The flow switching valve 12 is a four-way valve. The flow switching valve 12 switches the flow passage of the refrigerant discharged from the compressor 11 depending on which operations are performed by the refrigerant indoor units 2a to 2c and the heat-medium indoor unit 3a. In a heating operation, the flow switching valve 12 switches the flow passage of the refrigerant to a flow passage indicated by solid lines in Fig. 1, and in a cooling operation, the flow switching valve 12 switches the flow passage of the refrigerant to a flow passage indicated by dashed lines in Fig. 1. It should be noted that the flow switching valve 12 may be a combination of three-way valves or two-way valves.
[0016] The outdoor heat exchanger 13 is, for example, a fin-tube heat exchanger. The outdoor heat exchanger 13 causes heat exchange to be performed between air supplied by the outdoor fan 14 and the refrigerant. The outdoor heat exchanger 13 operates as a condenser in the cooling operation to condense and liquefy the refrigerant, and operates as an evaporator in the heating operation to evaporate and gasify the refrigerant.
[0017] The outdoor fan 14 is, for example, a propeller fan. The outdoor fan 14 supplies the outdoor heat exchanger 13 with ambient air of the outdoor unit 1. The rotation speed of the outdoor fan 14 is controlled by the outdoor control device 17, whereby the condensing performance or evaporating performance of the outdoor heat exchanger 13 is controlled. The accumulator 15 is provided on a suction side of the compressor 11 and has a function of separating liquid refrigerant and gas refrigerant from each other and a function of storing surplus refrigerant.
[0018] The outdoor refrigerant pipe 16 is one of pipes of the air-conditioning apparatus 100 through which the refrigerant flows, and is provided in a housing (not illustrated) of the outdoor unit 1. The outdoor refrigerant pipe 16 connects the outdoor heat exchanger 13, the accumulator 15, the compressor 11, and the flow switching valve 12 in this order. One of ends of the outdoor refrigerant pipe 16 that is close to the flow switching valve 12 is connected to the refrigerant pipe 65, and the other end of the outdoor refrigerant pipe 16 that is close to the outdoor heat exchanger 13 is connected to the refrigerant pipe 66.
[0019] The outdoor control device 17 controls the operations of the compressor 11, the flow switching valve 12, and the outdoor fan 14. The outdoor control device 17 is a processing device, a dedicated hardware such as an ASIC or an FPGA, or a combination of the processing device and the dedicated hardware. The above processing device is a processing device that includes a memory configured to store data and a program that are necessary for control and a CPU configured to execute the program. The outdoor control device 17 controls the driving frequency of the compressor 11, the flow passage of the flow switching valve 12, and the rotation speed of the outdoor fan 14 based on the results of detection by a pressure sensor (not illustrated) mounted in the outdoor unit 1 and configured to detect a refrigerant pressure and by a temperature sensor (not illustrated) mounted in the outdoor unit 1 and configured to detect a refrigerant temperature or an outside air temperature. The outdoor control device 17 can cause data communication to be performed between indoor control devices 25a to 25c mounted in the refrigerant indoor units 2a to 2c, an indoor control device 35a mounted in the heat-medium indoor unit 3a, and relay control devices 46a and 46b mounted in the relay units 4a and 4b.
[0020] The refrigerant indoor units 2a to 2c supply cooling loads or heating loads of the air-conditioned spaces with heat generated by the outdoor unit 1. The refrigerant indoor unit 2a includes a refrigerant heat exchanger 21a, an expansion valve 22a, an indoor fan 23a, an indoor refrigerant pipe 24a, and an indoor control device 25a. The refrigerant heat exchanger 21a is, for example, a fin-tube heat exchanger. The refrigerant heat exchanger 21a causes heat exchanger to be performed between air supplied by the indoor fan 23a and the refrigerant. The refrigerant heat exchanger 21a operates as a condenser during in the heating operation to condense and liquefy the refrigerant, and operates as an evaporator in the cooling operation to evaporate and gasify the refrigerant.
[0021] The expansion valve 22a is an electronic expansion valve whose opening degree is variably controlled. The expansion valve 22a is connected in series to the refrigerant heat exchanger 21a and decompresses and expands refrigerant that has flowed out from the refrigerant heat exchanger 21a or refrigerant that is to flow into the refrigerant heat exchanger 21a.
[0022] The indoor fan 23a is, for example, a cross flow fan. The indoor fan 23a supplies the refrigerant heat exchanger 21a with air in an air-conditioned space. The rotation speed of the indoor fan 23a is controlled by the indoor control device 25a, whereby the condensing performance or evaporating performance of the refrigerant heat exchanger 21a is controlled.
[0023] The indoor refrigerant pipe 24a is one of the pipes of the air-conditioning apparatus 100 through which the refrigerant flows, and is provided in a housing (not illustrated) of the refrigerant indoor unit 2a. The indoor refrigerant pipe 24a connects the refrigerant heat exchanger 21a and the expansion valve 22a. One of ends of the indoor refrigerant pipe 24a that is close to the refrigerant heat exchanger 21a is connected to the refrigerant pipe 65, and the other end of the indoor refrigerant pipe 24a that is close to the expansion valve 22a is connected to the refrigerant pipe 66.
[0024] The indoor control device 25a controls the operations of the expansion valve 22a and the indoor fan 23a. The indoor control device 25a is a processing device, dedicated hardware such as an ASIC or an FPGA, or a combination of the processing device and the dedicated hardware. The above processing device is a processing device that includes a memory configured to store data and a program that are necessary for control and a CPU configured to execute the program. The indoor control device 25a controls the opening degree of the expansion valve 22a and the rotation speed of the indoor fan 23a based on the results of detection by a temperature sensor (not illustrated) configured to detect the temperature in the air-conditioned space and by temperature sensors (not illustrated) configured to detect respective temperatures of the refrigerant at an outlet and an inlet of the refrigerant indoor unit 2a.
The temperature sensors are, for example, thermistors. It should be noted that the indoor control device 25a controls the opening degree of the expansion valve 22a and the rotation speed of the indoor fan 23a, for example, depending on the difference between the temperature in the air-conditioned space and a target temperature. [0025] The refrigerant indoor units 2b and 2c have the same configuration as the refrigerant indoor unit 2a. That is, the refrigerant indoor unit 2b includes a refrigerant heat exchanger 21 b, an expansion valve 22b, an indoor fan 23b, an indoor refrigerant pipe 24b, and an indoor control device 25b. Similarly, the refrigerant indoor unit 2c includes a refrigerant heat exchanger 21c, an expansion valve 22c, an indoor fan 23c, an indoor refrigerant pipe 24c, and an indoor control device 25c. Components included in each of the refrigerant indoor units 2a and 2b are also the same in configuration as those in the refrigerant indoor unit 2a, and their descriptions will thus be omitted.
[0026] The heat-medium indoor unit 3a supplies the cooling loads or heating loads of the air-conditioned spaces with heat obtained through conversion by the relay unit 4a. The heat-medium indoor unit 3a includes a heat-medium heat exchanger 31a, a flow control valve 32a, an indoor fan 33a, an indoor heat medium pipe 34a, and an indoor control device 35a. The heat-medium heat exchanger 31a is, for example, a fin-tube heat exchanger. The heat-medium heat exchanger 31a causes heat exchange to be performed between air supplied by the indoor fan 33a and the heat medium. It should be noted that the heat-medium heat exchanger 31a corresponds to the "first heat-medium heat exchanger" of the present disclosure.
[0027] The flow control valve 32a is a solenoid valve whose opening degree is variably controlled. The flow control valve 32a is connected in series to the heat-medium heat exchanger 31 a and adjusts the flow rate of a heat medium that flows through the heat-medium heat exchanger 31a.
[0028] The indoor fan 33a is, for example, a cross flow fan. The indoor fan 33a supplies the heat-medium heat exchanger 31a with air in an air-conditioned space. The rotation speed of the indoor fan 33a is controlled by the indoor control device 35a, whereby the heating performance or cooling performance of the heat-medium heat exchanger 31 a is controlled.
[0029] The indoor heat medium pipe 34a is a pipe connecting the heat-medium heat exchanger 31 a and the flow control valve 32a in the air-conditioning apparatus 100. The indoor heat medium pipe 34a is one of pipes through which the heat medium flows, and is provided in the housing (not illustrated) of the refrigerant indoor unit 2a. One of ends of the indoor heat medium pipe 34a that is close to the heat-medium heat exchanger 31 is connected to the heat medium pipe 71a, and the other end of the indoor heat medium pipe 34a that is close to the flow control valve 32a is connected to the heat medium pipe 72a.
[0030] The indoor control device 35a controls the operations of the flow control valve 32a and the indoor fan 33a. The indoor control device 35a is a processing device, dedicated hardware such as an ASIC or an FPGA, or a combination of the processing device and the dedicated hardware. The above processing device is a processing device that includes a memory configured to store data and a program that are necessary for control and a CPU configured to execute the program. The indoor control device 35a controls the opening degree of the flow control valve 32a and the rotation speed of the indoor fan 33a based on the results of detection by a temperature sensor (not illustrated) configured to detect the temperature of the air-conditioned space and temperature sensors (not illustrated) configured to detect respective temperatures of the heat medium at an outlet and an inlet of the heat-medium indoor unit 3a. The temperature sensors are, for example, therm istors. It should be noted that the indoor control device 35a controls the opening degree of the flow control valve 32a and the rotation speed of the indoor fan 33a, for example, depending on the difference between the temperature of the air-conditioned space and a target temperature. Furthermore, the indoor control device 35a may calculate the flow rate of the heat medium from the results of detection by pressure sensors provided in front of and behind the flow control valve 32a and a Cv value that is stored in advance and varies depending on the opening degree of the flow control valve 32a, and control the opening degree of the flow control valve 32a based on the result of the above calculation.
[0031] The relay unit 4a includes a relay heat exchanger 41a, an expansion valve 42a, a pump 43a, a relay refrigerant pipe 44a, a relay heat medium pipe 45a, and a relay control device 46a. The relay heat exchanger 41a is, for example, a plate heat exchanger. The relay heat exchanger 41a has a refrigerant flow passage (not illustrated) through which refrigerant supplied from the outdoor unit 1 flows and a heat medium flow passage (not illustrated) through which a heat medium that is circulated by the pump 43a flows. The relay heat exchanger 41a causes heat exchange to be performed between the refrigerant that flows through the refrigerant flow passage and the heat medium that flows through the heat medium flow passage. As a result, heat stored in the refrigerant supplied from the outdoor unit 1 is transferred to the heat medium. The relay heat exchanger 41a operates as a condenser in the heating operation to condense and liquefy the refrigerant, and operates as an evaporator in the cooling operation to evaporate and gasify the refrigerant.
[0032] The expansion valve 42a is an electronic expansion valve whose opening degree is variably controlled. The expansion valve 42a is connected in series to the relay heat exchanger 41 a and decompresses and expands refrigerant that has flowed out from the relay heat exchanger 41 a or refrigerant that is to flow into the relay heat exchanger 41a.
[0033] The pump 43a is, for example, an inverter-type centrifugal pump whose capacity can be controlled. The pump 43a includes a motor that is driven by an inverter, is driven by the motor, and is configured to apply a pressure to a heat medium that flows through a heat medium flow passage of the relay heat medium pipe 45b. It should be noted that referring to Fig. 1, the pump 43a is provided to produce such a cooling counterflow that the refrigerant and a heat medium flow in opposite directions in the cooling operation; however, the pump 43a may be provided to produce such a heating counterflow that the refrigerant and the heat medium flow in opposite directions in the heating operation. Furthermore, the pump 43a is provided in the relay unit 4a, but is not provided at the heat medium pipe 71a or 72a, which connects the relay unit 4a and the heat-medium indoor unit 3a.
[0034] In the air-conditioning apparatus 100, the relay refrigerant pipe 44a is one of the pipes through which the refrigerant flows, and is provided in a housing (not illustrated) of the relay unit 4a. The relay refrigerant pipe 44a connects the refrigerant flow passage of the relay heat exchanger 41a and the expansion valve 42a. One of ends of the relay refrigerant pipe 44a that is close to the relay heat exchanger 41a is connected to the refrigerant pipe 65, and the other end of the relay refrigerant pipe 44a that is close to the expansion valve 42a is connected to the refrigerant pipe 66.
[0035] In the air-conditioning apparatus 100, the relay heat medium pipe 45a is one of the pipes through which the heat medium flows, and is provided in the housing (not illustrated) of the relay unit 4a. The relay heat medium pipe 45a connects the heat medium flow passage of the relay heat exchanger 41a and the pump 43a. One of ends of the relay heat medium pipe 45a that is close to the relay heat exchanger 41a is connected to the heat medium pipe 71a, and the other end of the relay heat medium pipe 45a that is close to the pump 43a is connected to the heat medium pipe 72a. [0036] The relay control device 46a controls the operations of the expansion valve 42a and the pump 43a. The relay control device 46a is a processing device, dedicated hardware such as an ASIC or an FPGA, or a combination of the processing device and the dedicated hardware. The above processing device is a processing device includes a memory configured to store data and a program that are necessary for control and a CPU configured to execute the program. The relay control device 46a controls the opening degree of the expansion valve 42a based on the results of detection by temperature sensors (not illustrated) configured to detect respective refrigerant temperatures at an outlet and an inlet of the refrigerant side of the relay heat exchanger 41 a. Alternatively, the relay control device 46a may control the opening degree of the expansion valve 42a, depending on the operating capacity of the heat-medium indoor unit 3a. The relay control device 46a may perform data communication with the indoor control device 25a to control the expansion valve 42a in association with the expansion valves 22a mounted in the refrigerant indoor units 2a to 2c. Furthermore, the relay control device 46a controls the driving frequency of the pump 43a based on the results of detection by pressure sensors (not illustrated) that are provided at an outlet and an inlet of the pump 43a to detect the pressure of the heat medium and a graph associating the capability value or other properties of the pump 43a with each other. Alternatively, the relay control device 46a may control the driving frequency of the pump 43a, depending on the operating capacity of the heat-medium indoor unit 3a. [0037] The relay unit 4b is the same in configuration as the relay unit 4a. That is, the relay unit 4b includes a relay heat exchanger 41b, an expansion valve 42b, a pump 43b, a relay refrigerant pipe 44b, a relay heat medium pipe 45b, and a relay control device 46b. Components included in the relay unit 4b are the same in configuration as those of the relay unit 4a, and their descriptions will thus be omitted. It should be noted that the pump 43b is provided in the relay unit 4b, but is not provided at the heat medium pipe 73 or 74, which connects the relay unit 4b and the hot water storage tank 6. Furthermore, the relay heat exchangers 41a and 41b correspond to the "first relay heat exchanger" and the "second relay heat exchanger" of the present disclosure, respectively. Furthermore, the pumps 43a and 43b correspond to the "first pump" and the "second pump" of the present disclosure, respectively [0038] Unlike the relay unit 4a, the relay unit 4b is connected to the hot water storage tank 6. That is, one of ends of the relay refrigerant pipe 44b that is close to the relay heat exchanger 41 b is connected to the heat medium pipe 73, and the other end of the relay refrigerant pipe 44b that is close to the pump 43b is connected to the heat medium pipe 74.
[0039] The relay control device 46b controls the opening degree of the expansion valve 42b and the driving frequency of the pump 43b based on the results of detection by sensors in such a manner as to cause the temperature of a heat medium that is supplied to the hot water storage tank 6 through the heat medium pipe 73 to reach a required temperature. The above sensors are temperature sensors (not illustrated) configured to detect refrigerant temperatures at an outlet and an inlet of a refrigerant side of the relay heat exchanger 41 b and temperature sensors (not illustrated) configured to detect heat medium temperatures at an outlet and an inlet of a heat medium side of the relay heat exchanger 41 b. It should be noted that the required temperature of the heat medium is a temperature that is set in response to an instruction to the hot water storage tank 6 from, for example, a remote control (not illustrated) and that is calculated from a desired pouring hot-water temperature for a user. Furthermore, in the case where the air-conditioning apparatus 100 performs the cooling operation, the relay control device 46b fixes the opening degree of the expansion valve 42b to a value at which the expansion valve 42b is fully closed, and stops the driving of the pump 43b.
[0040] The air-conditioning apparatus 100 includes a refrigerant circuit 91 through which the refrigerant circulates and heat medium circuits 93 and 94 through which the heat medium circulates. In the refrigerant circuit 91, the compressor 11 of the outdoor unit 1, the flow switching valve 12 of the outdoor unit 1, the outdoor heat exchanger 13 of the outdoor unit 1, the accumulator 15 of the outdoor unit 1, the refrigerant heat exchangers 21a to 21c of the refrigerant indoor units 2a to 2c, the expansion valves 22a to 22c of the refrigerant indoor units 2a to 2c, the refrigerant flow passages of the relay heat exchangers 41 a and 41 b of the relay units 4a and 4b, and the expansion valves 42a and 42b of the relay units 4a and 4b are connected by the outdoor refrigerant pipe 16, the indoor refrigerant pipes 24a to 24c, the relay refrigerant pipes 44a and 44b, and the refrigerant pipes 65 and 66. The compressor 11 causes the refrigerant to circulate in the refrigerant circuit 91. It should be noted that the refrigerant circuit 91 corresponds to the 'first refrigerant circuit" of the present disclosure and the refrigerant flowing in the refrigerant circuit 91 corresponds to the "first refrigerant" of the present disclosure.
[0041] In the heat medium circuit 93, the heat medium flow passage of the relay heat exchanger 41 a of the relay unit 4a, the pump 43a of the relay unit 4a, the heat-medium heat exchanger 31 a of the heat-medium indoor unit 3a, and the flow control valve 32a of the heat-medium indoor unit 3a are connected by the heat medium pipes 71 a and 72a.
The pump 43a causes the heat medium to circulate in the heat medium circuit 93. It should be noted that the heat medium circuit 93 corresponds to the "first heat medium circuit" of the present disclosure.
[0042] In the heat medium circuit 94, the heat medium side of the relay heat exchanger 41 b of the relay unit 4b, the pump 43b of the relay unit 4b, and the hot water storage tank 6 are connected by the heat medium pipes 73 and 74. The pump 43b causes the heat medium to circulate in the heat medium circuit 94. It should be noted that the heat medium circuit 94 corresponds to the "second heat medium circuit" of the present disclosure.
[0043] The air-conditioning apparatus 100 performs the cooling operation or the heating operation on the basis of instructions to the refrigerant indoor units 2a to 2c and the heat-medium indoor unit 3a that are given from the remote control (not illustrated) or other devices. The operation is switched between the cooling operation and the heating operation by a switching operation of the flow switching valve 12 of the outdoor unit 1. In Fig. 2, solid arrows indicate the flow of refrigerant in the heating operation, and dotted arrows indicate the flow of refrigerant in the cooling operation. The flow of refrigerant in each of the operations will be described below.
[0044] In the heating operation, high-temperature and high-pressure gas refrigerant discharged from the compressor 11 flows out from the outdoor unit 1 through the flow switching valve 12, and branches to flow into the refrigerant indoor units 2a to 2c and the relay units 4a and 4b, through the refrigerant pipe 65. The refrigerant that has flowed into the refrigerant indoor units 2a to 2c condenses and liquefies by exchanging heat, in the refrigerant heat exchangers 21a to 21c, with air supplied by the indoor fans 23a to 23c. At this time, the refrigerant transfers heat to air in the air-conditioned spaces in which the refrigerant indoor units 2a to 2c are installed, thereby heating the air-conditioned spaces. The refrigerant that has flowed out from the refrigerant heat exchangers 21a to 21c is decompressed by the expansion valves 22a to 22c, flows out from the refrigerant indoor units 2a to 2c, and flows into the outdoor unit 1 through the refrigerant pipe 66.
[0045] The refrigerant that has flowed into the relay unit 4a condenses and liquefy by exchanging heat, in the relay heat exchanger 41a, with the heat medium that is circulated by the pump 43a. At this time, the refrigerant transfers heat to the heat medium, whereby the heat medium is heated. The refrigerant that has flowed out from the relay heat exchanger 41a is decompressed in the expansion valve 42a, flows out from the relay unit 4a, joins, in the refrigerant pipe 66, the refrigerant that has flowed out from the refrigerant indoor units 2a to 2c, and flows into the outdoor unit 1.
[0046] The refrigerant that has flowed into the relay unit 4b condenses and liquefies by exchanging heat, in the relay heat exchanger 41 b, with the heat medium that is circulated by the pump 43b. At this time, the refrigerant transfers heat to the heat medium, whereby the heat medium is heated. The refrigerant that has flowed out from the relay heat exchanger 41 b is decompressed in the expansion valve 42b, flows out from the relay unit 4b, joins, in the refrigerant pipe 66, the refrigerant that has flowed out from the refrigerant indoor units 2b to 2c, and flows into the outdoor unit 1.
[0047] The refrigerant that has flowed into the outdoor unit 1 flows into the outdoor heat exchanger 13. The refrigerant that has flowed into the outdoor heat exchanger 13 evaporates and gasifies by exchanging heat with air supplied by the outdoor fan 14. The refrigerant that has flowed out from the outdoor heat exchanger 13 is re-sucked into the compressor 11 via the flow switching valve 12 and the accumulator 15.
[0048] Furthermore, the heat medium heated in the relay heat exchanger 41a flows into the heat-medium indoor unit 3a through the heat medium pipe 71a. The heat medium that has flowed into the heat-medium indoor unit 3a exchanges heat, in the heat-medium heat exchanger 31a, with air supplied by the indoor fan 33a. At this time, the heat medium transfers heat to air in an air-conditioned space in which the heat-medium indoor unit 3a is installed, whereby the air-conditioned space is heated. The heat medium that has flowed out from the heat-medium heat exchanger 31 a flows out from the heat-medium indoor unit 3a through the flow control valve 32a and flows into the relay unit 4a through a heat medium pipe 6b.
[0049] Furthermore, the heat medium heated in the relay heat exchanger 41 b passes through the heat medium pipe 73 and is stored in the hot water storage tank 6. Of the heat medium stored in the hot water storage tank 6, the heat medium not supplied to the use side flows into the relay unit 4b through the heat medium pipe 74. Thus, the heat medium to be supplied from the outside to the hot water storage tank 6 is heated by circulating through the heat medium circuit 94 and is stored in the hot water storage tank 6.
[0050] Furthermore, in the cooling operation, high-temperature and high-pressure gas refrigerant discharged from the compressor 11 flows into the outdoor heat exchanger 13 through the flow switching valve 12. The refrigerant that has flowed into the outdoor heat exchanger 13 condenses and liquefies by exchanging heat with air supplied by the outdoor fan 14. The refrigerant that has flowed out from the outdoor heat exchanger 13 branches to flow into the refrigerant indoor units 2a to 2c and the relay units 4a and 4b, through the refrigerant pipe 66.
[0051] The refrigerant that has flowed into the refrigerant indoor units 2a to 2c is decompressed in the expansion valves 22a to 22c to change into low-pressure two-phase gas-liquid refrigerant, and the low-pressure two-phase gas-liquid refrigerant then flows into the refrigerant heat exchangers 21 a to 21c. The refrigerant that has flowed into the refrigerant heat exchangers 21a to 21c evaporates and gasifies by exchanging heat with air supplied by the indoor fans 23a to 23c. At this time, the refrigerant receives heat from air in the air-conditioned spaces in which the refrigerant indoor units 2a to 2c are installed, whereby the air-conditioned spaces are cooled. The refrigerant that has flowed out from the refrigerant heat exchanger 21a flows into the outdoor unit 1 through the refrigerant pipe 65.
[0052] The refrigerant that has flowed into the relay unit 4a is decompressed in the expansion valve 42a to change into low-temperature two-phase gas-liquid refrigerant, and the low-temperature two-phase gas-liquid refrigerant then flows into the relay heat exchanger 41 a. The refrigerant that has flowed into the relay heat exchanger 41 a evaporates and gasifies by exchanging heat with the heat medium that is circulated by the pump 43a. At this time, the refrigerant receives heat from the heat medium, whereby the heat medium is cooled. The refrigerant that has flowed out from the relay heat exchanger 41 a joins, in the refrigerant pipe 65, the refrigerant that has flowed out from the refrigerant indoor units 2a to 2c, and flows into the outdoor unit 1. The refrigerant that has flowed into the outdoor unit 1 is re-sucked into the compressor 11 via the flow switching valve 12 and the accumulator 15.
[0053] Furthermore, the heat medium cooled in the relay heat exchanger 41a flows into the heat-medium indoor unit 3a through a heat medium pipe 6a. The heat medium that has flowed into the heat-medium indoor unit 3a exchanges heat, in the heat-medium heat exchanger 31 a, with air supplied by the indoor fan 33a. At this time, the heat medium receives heat from air in the air-conditioned space in which the heat-medium indoor unit 3a is installed, whereby the air-conditioned space is cooled. The heat medium that has flowed out from the heat-medium heat exchanger 31 a flows out from the heat-medium indoor unit 3a through the flow control valve 32a and flows into the relay unit 4a through the heat medium pipe 6b.
[0054] In the cooling operation, in the relay unit 4b, the opening degree of the expansion valve 42b is fixed at a value at which the expansion valve 42b is fully closed, and the driving of the pump 43b is under suspension. Therefore, in the cooling operation, in the relay heat exchanger 41 b of the relay unit 4b, actually, heat exchange is not performed between the refrigerant that circulates through the refrigerant circuit 91 and the heat medium that circulates through the heat medium circuit 94.
[0055] As described above, in the air-conditioning apparatus 100 of Embodiment 1, the relay unit 4b includes the pump 43b. Therefore, it is not necessary to provide a pump at the heat medium pipe 73 or 74, which connects the relay unit 4b and the hot water storage tank 6. Thus, in the air-conditioning apparatus 100 of Embodiment 1, it is not necessary to provide a pump at the time of installing the hot water storage tank 6, and it is therefore possible to reduce the cost of on-site work.
[0056] Furthermore, in general, an energy loss occurs in the case where heat exchange is performed between refrigerant and a heat medium. Meanwhile, in the case where a heat exchanger of an indoor unit handles mildly-flammable refrigerant, it is necessary to take safety measures against occurrence of a refrigerant leak. The air-conditioning apparatus 100 of Embodiment 1 includes not only the refrigerant indoor units 2a to 2c and the hot water storage tank 6 but also the heat-medium indoor unit 3a as load-side devices, thereby reducing the occurrence of an energy loss in the air-conditioning apparatus 100 as a whole. Furthermore, the heat-medium indoor unit 3a, which is provided with the heat-medium heat exchanger 31a, does not need to be prepared for a refrigerant leak in an indoor space. In addition, it is possible to reduce the amount of refrigerant that is contained in a sealed state in the air-conditioning apparatus, as compared with an air-conditioning apparatus including only a refrigerant indoor unit.
Therefore, in the air-conditioning apparatus 100 of Embodiment 1, as the configuration of the indoor unit, it is possible to select an appropriate configuration in view of an energy-saving efficiency and whether safety measures are necessary or not.
[0057] Embodiment 2 Fig. 2 is a circuit diagram of an air-conditioning apparatus 100A according to Embodiment 2. As illustrated in Fig. 2, in Embodiment 2, the air-conditioning apparatus 100A includes a relay unit 4c. In this regard, Embodiment 2 is different from Embodiment 1. Regarding Embodiment 2, components that are the same as those in Embodiment 1 will be denoted by the same reference signs, and their descriptions will thus be omitted. The following description concerning Embodiment 2 is made by referring mainly to the differences between Embodiments 1 and 2.
[0058] The relay unit 4c is connected in series to the relay unit 4b and the hot water storage tank 6. Specifically, the relay unit 4b and the hot water storage tank 6 are connected to each other by the heat medium pipe 73 through which the heat medium flows. Furthermore, the hot water storage tank 6 and the relay unit 4c are connected to each other by a heat medium pipe 75 through which the heat medium flows. Furthermore, the relay unit 4c and the relay unit 4b are connected to each other by a heat medium pipe 76 through which the heat medium flows.
[0059] The relay unit 4c is the same in configuration as the relay units 4a and 4b. That is, the relay unit 4c includes a relay heat exchanger 41 c, an expansion valve 42c, a pump 43c, a relay refrigerant pipe 44c, a relay heat medium pipe 45c, and a relay control device 46c. In addition, components included in the relay unit 4c are also the same in configuration as those in each of the relay units 4a and 4b, and their descriptions will thus be omitted. It should be noted that the relay unit 4c corresponds to the "third relay unit" of the present disclosure; the relay heat exchanger 41c corresponds to the "third relay heat exchanger" of the present disclosure; and the pump 43c corresponds to the "third pump" of the present disclosure.
[0060] The relay heat medium pipes 45b and 45c of the relay units 4b and 4c are connected to the heat medium pipes 73, 75, and 76 in the following manner. One of ends of the relay heat medium pipe 45b that is close to the relay heat exchanger 41 b is connected to the heat medium pipe 73, and the other end of the relay heat medium pipe 45b that is close to the pump 43b is connected to the heat medium pipe 76.
Furthermore, one of ends of the relay heat medium pipe 45c that is close to the relay heat exchanger 41 c is connected to the heat medium pipe 76, and the other end of the relay heat medium pipe 45c that is close to the pump 43c is connected to the heat medium pipe 75.
[0061] The relay control device 46c controls the opening degree of the expansion valve 42c and the driving frequency of the pump 43c based on the results of detection by sensors in such a manner as to cause the temperature of a heat medium that is supplied to the hot water storage tank 6 through the heat medium pipe 73 to reach a required temperature. The above sensors are temperature sensors (not illustrated) configured to detect refrigerant temperatures at an outlet and an inlet a refrigerant side of the relay heat exchanger 41c and temperature sensors (not illustrated) configured to detect heat medium temperatures at an outlet and an inlet of a heat medium side of the relay heat exchanger 41 c.
[0062] Furthermore, the relay control devices 46b and 46c perform data communication with each other to control the expansion valves 42b and 42c and the pumps 43b and 43c in association with each other. Specifically, in the case where the load is low, that is, a required temperature for the hot water storage tank 6 is low, only either the pump 43b or 43c is driven. In contrast, in the case where the load is high, that is, the required temperature for the hot water storage tank 6 is high, both the pumps 43b and 43c are driven, for example, with an output of 100%. Furthermore, in the case where the difference between the outlet-inlet temperature difference ATr_b of the refrigerant side of the relay unit 4b and the outlet-inlet temperature difference ATr_c of the refrigerant side of the relay unit 4c is greater than or equal to the predetermined value, the opening degrees of the expansion valves 42b and 42c and the distribution of outputs from the pumps 43b and 43c are adjusted to decrease the above difference. It should be noted that the difference between the outlet-inlet temperature differences ATr_b and ATr_c corresponds to differences between the results of detection by the temperature sensors configured to detect refrigerant temperatures at the outlets of the refrigerant sides of the relay heat exchangers 41 b and 41c and the results of detection by the temperature sensors configured to detect refrigerant temperatures at the inlets of the refrigerant sides.
[0063] In such a manner, in the refrigerant circuit 91 in Embodiment 2, the compressor 11 of the outdoor unit 1, the flow switching valve 12 of the outdoor unit 1, the outdoor heat exchanger 13 of the outdoor unit 1, the accumulator 15 of the outdoor unit 1, the refrigerant heat exchangers 21a to 21c of the refrigerant indoor units 2a to 2c, the expansion valves 22a to 22c of the refrigerant indoor units 2a to 2c, the refrigerant flow passages of the relay heat exchangers 41 a to 41c of the relay units 4a to 4c, and the expansion valves 42a to 42c of the relay units 4a to 4c are connected by the outdoor refrigerant pipe 16, the indoor refrigerant pipes 24a to 24c, the relay refrigerant pipes 44a to 44c, and the refrigerant pipes 65 and 66.
[0064] Furthermore, in the heat medium circuit 94 of Embodiment 2, the heat medium flow passage of the relay heat exchanger 41 b of the relay unit 4b, the pump 43b of the relay unit 4b, the heat medium flow passage of the relay heat exchanger 41c of the relay unit 4c, the pump 43c of the relay unit 4c, and the hot water storage tank 6 are connected by the relay heat medium pipe 45b, the relay heat medium pipe 45c, and the heat medium pipes 73, 75, and 76. The pumps 43b and 43c cause the heat medium to circulate in the heat medium circuit 94. It should be noted that the heat medium circuit 94 of Embodiment 2 also corresponds to the "second heat medium circuit" of the present disclosure.
[0065] The following description concerning the flow of refrigerant in the heating operation is made by referring mainly to the differences between Embodiments 1 and 2. In the heating operation, high-temperature and high-pressure gas refrigerant discharged from the compressor 11 flows out from the outdoor unit 1 through the flow switching valve 12 and branches to flow into the refrigerant indoor units 2a to 2c and the relay units 4a to 4c through the refrigerant pipe 65.
[0066] The refrigerant that has flowed into the relay unit 4c condenses and liquefy by exchanging heat in the relay heat exchanger 41c with the heat medium circulated by the pump 43c. At this time, the refrigerant transfers heat to the heat medium, whereby the heat medium is heated. The refrigerant that has flowed out from the relay heat exchanger 41 c is decompressed in the expansion valve 42c, flows out from the relay unit 4c, joints in the refrigerant pipe 66, the refrigerant that has flowed out from the refrigerant indoor units 2c to 2c, and flows into the outdoor unit 1.
[0067] Furthermore, the heat medium heated in the relay heat exchanger 41c passes through the heat medium pipe 76 and is further heated in the relay heat exchanger 41 b. The heat medium heated in the relay heat exchanger 41 b passes through the heat medium pipe 73 and is stored in the hot water storage tank 6. Of the heat medium stored in the hot water storage tank 6, the heat medium not supplied to the use side flows into the relay heat exchanger 41c through the heat medium pipe 75. In such a manner, the heat medium to be supplied from the outside to the hot water storage tank 6 circulates in the heat medium circuit 94, and as a result, the heat medium is heated and then stored in the hot water storage tank 6.
[0068] As described above, in the air-conditioning apparatus 100A of Embodiment 2, the relay units 4b and 4c include the pumps 43b and 43c. Therefore, it is not necessary to provide a pump at the heat medium pipe 73, 75, or 76. Accordingly, in the air-conditioning apparatus 100A of Embodiment 2, it is not necessary to provide a pump at the time of installing the hot water storage tank 6, and it is possible to reduce the cost of on-site work.
[0069] Furthermore, the air-conditioning apparatus 100A of Embodiment 2 includes not only the refrigerant indoor units 2a to 2c and the hot water storage tank 6 but also the heat-medium indoor unit 3a as load-side devices. Thus, the occurrence of an energy loss in the air-conditioning apparatus 100A as a whole is reduced. Furthermore, the heat-medium indoor unit 3a in which the heat-medium heat exchanger 31a is provided does not need to be prepared for a refrigerant leak in the indoor space. In addition, it is possible to reduce the amount of refrigerant that is contained in a sealed state in the air-conditioning apparatus, as compared with an air-conditioning apparatus including a refrigerant indoor unit only. Therefore, in the air-conditioning apparatus 100A of Embodiment 2, as the configuration of the indoor unit, it is possible to select an appropriate configuration in view of an energy-saving efficiency and whether safety measures are necessary or not.
[0070] Furthermore, the heat medium circuit 94 of the air-conditioning apparatus 100A of Embodiment 2 includes two relay heat exchangers 41 b and 41c that are connected in series to each other. Therefore, it is possible to store a heat medium having a higher temperature in the hot water storage tank 6 than in Embodiment 1, and supply it to the use side.
[0071] Embodiment 3 Fig. 3 is a circuit diagram of an air-conditioning apparatus according to Embodiment 3. As illustrated in Fig. 3, in Embodiment 3, the air-conditioning apparatus includes a heat-medium indoor unit 3b. In this regard, Embodiment 3 is different from Embodiment 2. Regarding Embodiment 3, components that are the same as those in in Embodiment 2 will be denoted by the same reference signs, and their descriptions will thus be omitted. The following description concerning Embodiment 3 is made by referring mainly to the differences between Embodiments 2 and 3.
[0072] The heat-medium indoor unit 3b is connected in series to the relay unit 4b and the hot water storage tank 6. Specifically, the relay unit 4b and the hot water storage tank 6 are connected by the heat medium pipe 73 through which the heat medium flows. Furthermore, the hot water storage tank 6 and the heat-medium indoor unit 3b are connected by a heat medium pipe 77 through which the heat medium flows.
Furthermore, the heat-medium indoor unit 3b and the relay unit 4c are connected by a heat medium pipe 78 through which the heat medium flows. Moreover, the relay unit 4c and the relay unit 4b are connected by the heat medium pipe 76 through which the heat medium flows.
[0073] The heat-medium indoor unit 3b is the same in configuration as the heat-medium indoor unit 3a. That is, the heat-medium indoor unit 3b includes a heat-medium heat exchanger 31 b, a flow control valve 32b, an indoor fan 33b, an indoor heat medium pipe 34b, and an indoor control device 35b. Components included in the heat-medium indoor unit 3b are the same in configuration as those in the heat-medium indoor unit 3a. It should be noted that the heat-medium indoor unit 3b corresponds to the "second heat-medium indoor unit" of the present disclosure, and the heat-medium heat exchanger 31 b corresponds to the "second heat-medium heat exchanger" of the
present disclosure.
[0074] The relay heat medium pipes 45b and 45c of the relay units 4b and 4c and the indoor heat medium pipe 34b of the heat-medium indoor unit 3b are connected to the heat medium pipes 73, 76, 77, and 78 in the following manner. To be more specific, one of ends of the relay heat medium pipe 45b that is close to the relay heat exchanger 41 b is connected to the heat medium pipe 73, and the other end of the relay heat medium pipe 45b that is close to the pump 43b is connected to the heat medium pipe 76. Furthermore, one of ends of the relay heat medium pipe 45c that is close to the relay heat exchanger 41 c is connected to the heat medium pipe 76, and the other end of the relay heat medium pipe 45c that is close to the pump 43c is connected to the heat medium pipe 78. In addition, one of ends of the indoor heat medium pipe 34b that is close to the heat-medium heat exchanger 31 b is connected to the heat medium pipe 77, and the other end of the indoor heat medium pipe 34b that is close to the flow control valve 32b is connected to the heat medium pipe 78.
[0075] Thus, in the heat medium circuit 94 in Embodiment 3, the heat medium flow passage of the relay heat exchanger 41b of the relay unit 4b, the pump 43b of the relay unit 4b, the heat medium flow passage of the relay heat exchanger 41c of the relay unit 4c, the pump 43c of the relay unit 4c, the hot water storage tank 6, the heat-medium heat exchanger 31 b of the heat-medium indoor unit 3b, and the flow control valve 32b of the heat-medium indoor unit 3b are connected by the relay heat medium pipe 45b, the relay heat medium pipe 45c, the indoor heat medium pipe 34b, and the heat medium pipes 73, 75, and 76. The pumps 43b and 43c cause the heat medium to circulate in the heat medium circuit 94. It should be noted that the heat medium circuit 94 of Embodiment 3 also corresponds to the "second heat medium circuit" of the present
disclosure.
[0076] It should be noted that the relay control device 46c of the relay unit 4c may set, as the required temperature of the heat medium, a temperature based on an instruction to the hot water storage tank 6 from the remote control or other devices and an instruction to the heat-medium indoor unit 3b from the remote control (not illustrated). [0077] The following description concerning the flow of refrigerant in the heating operation is made by referring mainly to the differences between Embodiments 2 and 3.
After being heated in the relay heat exchanger 41c, the heat medium that is circulated by the pumps 43b and 43c passes through the heat medium pipe 76 and is further heated in the relay heat exchanger 41b. The heat medium heated in the relay heat exchanger 41 b passes through the heat medium pipe 73 and is stored in the hot water storage tank 6. Of the heat medium stored in the hot water storage tank 6, the heat medium not supplied to the use side flows into the heat-medium indoor unit 3b through the heat medium pipe 77.
[0078] The heat medium that has flowed into the heat-medium indoor unit 3b exchanges heat in the heat-medium heat exchanger 31b, with air supplied by the indoor fan 33b.
At this time, the heat medium transfers heat to air in an air-conditioned space in which the heat-medium indoor unit 3b is provided, whereby the air-conditioned space is heated. The heat medium that has flowed out from the heat-medium heat exchanger 31 b flows out from the heat-medium indoor unit 3b through the flow control valve 32b and flows into the relay unit 4c through the heat medium pipe 78. In such a way, the heat medium to be supplied from the outside to the hot water storage tank 6 is circulated in the heat medium circuit 94, and as a result, the heat medium is heated and then stored in the hot water storage tank 6. Furthermore, the heat medium stored in the hot water storage tank 6 is primarily used in the hot water storage tank 6 and is secondarily used in the heat-medium indoor unit 3b.
[0079] As described above, in the air-conditioning apparatus 100B of Embodiment 3, the relay units 4b and 4c include the pumps 43b and 43c. Therefore, it is not necessary to provide a pump at any of the heat medium pipes 73 and 76 to 78. Therefore, in the air-conditioning apparatus 100B of Embodiment 3, it is not necessary to provide a pump at the time of installing the hot water storage tank 6, and it is possible to reduce the cost of on-site work.
[0080] The air-conditioning apparatus 1008 of Embodiment 3 includes not only the refrigerant indoor units 2a to 2c and the hot water storage tank 6 but also the heat-medium indoor units 3a and 3b as load-side devices. Thus, the occurrence of an energy loss in the air-conditioning apparatus 100B as a whole is reduced.
Furthermore, the heat-medium indoor units 3a and 3b in which the heat-medium heat exchanger 31 a are provided do not need to be prepared for a refrigerant leak in the indoor space. In addition, it is possible to reduce the amount of refrigerant that is contained in a sealed state in the air-conditioning apparatus, as compared with an air-conditioning apparatus including a refrigerant indoor unit only. Thus, in the air-conditioning apparatus 1008 of Embodiment 3, as the configuration of the indoor unit, it is possible to select an appropriate configuration in view of an energy-saving efficiency and whether safety measures are necessary or not.
[0081] The heat medium circuit 94 of the air-conditioning apparatus 100B of Embodiment 3 includes two relay heat exchangers 41 b and 41c that are connected in series to each other. Thus, it is possible to store a heat medium having a higher temperature in the hot water storage tank 6 than in Embodiment 1 and supply it to the use side.
[0082] Furthermore, the heat medium circuit 94 of the air-conditioning apparatus of Embodiment 3 includes the hot water storage tank 6 and the heat-medium heat exchanger 31 b of the heat-medium indoor unit 3b. Thus, the heat medium heated by circulating in the heat medium circuit 94 can be secondarily used in the heat-medium indoor unit 3b, and the air-conditioning apparatus 100B can be efficiently operated. [0083] Embodiment 4 Fig. 4 is a circuit diagram of an air-conditioning apparatus 100C according to Embodiment 4. As illustrated in Fig. 4, in Embodiment 4, the air-conditioning apparatus 100C includes a heat-medium temperature raising unit 5. In this regard, Embodiment 4 is different from Embodiment 1. The following description concerning Embodiment 4 is made by referring mainly to the differences between Embodiments 1 and 4. Regarding Embodiment 4, components of Embodiment 4 that are the same as those of Embodiment 1 will be denoted by the same reference signs, and their descriptions will thus be denoted.
[0084] The outdoor unit 1 and the heat-medium temperature raising unit 5 are connected by the refrigerant pipes 65 and 66 through which the refrigerant flows. The heat-medium temperature raising unit 5 is connected to the outdoor unit 1 in parallel with the refrigerant indoor units 2a to 2c and the relay units 4a and 4b. Furthermore, the heat-medium temperature raising unit 5 and the hot water storage tank 6 are connected to by a heat medium pipe 79 through which the heat medium flows, and the hot water storage tank 6 and the relay unit 4b are connected by a heat medium pipe 80 through which the heat medium flows. Moreover, the relay unit 4b and the heat-medium temperature raising unit 5 are connected by a heat medium pipe 81 through which the heat medium flows.
[0085] The heat-medium temperature raising unit 5 heats the heat medium to a high temperature, with the refrigerant supplied from the outdoor unit 1. The heat-medium temperature raising unit 5 includes an upper heat exchanger 51, a lower heat exchanger 52, an expansion valve 53, a compressor 54, an expansion valve 55, a temperature-raising primary refrigerant pipe 56, a temperature-raising secondary refrigerant pipe 57, and a temperature-raising heat medium pipe 58. The upper heat exchanger 51 is, for example, a plate heat exchanger. The upper heat exchanger 51 includes a primary refrigerant flow passage (not illustrated) through which the refrigerant supplied from the outdoor unit 1 and circulating in the refrigerant circuit 91 flows and a secondary refrigerant flow passage (not illustrated) through which refrigerant caused by the compressor 54 to circulate in the refrigerant circuit 92 (to be described later) flows.
The upper heat exchanger 51 causes heat exchange to be performed between the refrigerant that flows through the primary refrigerant flow passage and the heat medium that flows through the secondary refrigerant flow passage. This causes heat stored in the refrigerant that flows in the refrigerant circuit 91 to be transferred to the refrigerant that flows in the refrigerant circuit 92. The upper heat exchanger 51 operates as an evaporator to evaporate and gasify the refrigerant that flows in the refrigerant circuit 92. [0086] The lower heat exchanger 52 is, for example, a plate heat exchanger. The lower heat exchanger 52 has a refrigerant flow passage (not illustrated) through which the refrigerant caused by the compressor 54 to circulate in the refrigerant circuit 92 flows and a heat medium flow passage (not illustrated) through which the heat medium caused by the pump 43b to circulate in the heat medium circuit 94 flows. The lower heat exchanger 52 causes heat exchange to be performed between the refrigerant that flows through the refrigerant flow passage and the heat medium that flows through the heat medium flow passage. This causes heat stored in the refrigerant that flows in the refrigerant circuit 92 to be transferred to the heat medium that flows in the heat medium circuit 94. The lower heat exchanger 52 operates as a condenser to condense and liquefy the refrigerant that flows in the refrigerant circuit 92.
[0087] The expansion valve 53 is an electronic expansion valve whose opening degree is variably controlled. The expansion valve 53 is connected in series to the primary refrigerant flow passage of the upper heat exchanger 51 and decompresses and expands refrigerant that flows out from the upper heat exchanger 51 or refrigerant that flows into the upper heat exchanger 51.
[0088] The compressor 54 sucks low-temperature and low-pressure gas refrigerant, compresses the low-temperature and low-pressure gas refrigerant to change it into high-temperature and high-pressure gas refrigerant, and discharges the high-temperature and high-pressure gas refrigerant. The compressor 54 is connected in series between the upper heat exchanger 51 and the lower heat exchanger 52. The compressor 54 is, for example, an inverter compressor whose capacity can be controlled. It should be noted that the compressor 54 corresponds to the "second compressor" of the present disclosure.
[0089] The expansion valve 55 is an electronic expansion valve whose opening degree is variably controlled. The expansion valve 55 is connected between the lower heat exchanger 52 and the upper heat exchanger 51 and decompresses and expands refrigerant that has flowed out from the lower heat exchanger 52 and is to flow into the upper heat exchanger 51.
[0090] In the air-conditioning apparatus 100C, the temperature-raising primary refrigerant pipe 56 is one of pipes through which the refrigerant flows, and is provided in a housing (not illustrated) of the heat-medium temperature raising unit 5. The temperature-raising primary refrigerant pipe 56 connects the refrigerant flow passage of the upper heat exchanger 51 and the expansion valve 53. One of ends of the temperature-raising primary refrigerant pipe 56 that is close to the upper heat exchanger 51 is connected to the refrigerant pipe 65, and the other end of the temperature-raising primary refrigerant pipe 56 that is close to the expansion valve 53 is connected to the refrigerant pipe 66.
[0091] In the air-conditioning apparatus 100C, the temperature-raising secondary refrigerant pipe 57 is one of the pipes through which the refrigerant flows, and is provided in the housing of the heat-medium temperature raising unit 5 and independent of the temperature-raising primary refrigerant pipe 56. The temperature-raising secondary refrigerant pipe 57 sequentially connects the secondary refrigerant flow passage of the upper heat exchanger 51, the expansion valve 55, the refrigerant flow passage of the lower heat exchanger 52, and the compressor 54 in this order. [0092] In the air-conditioning apparatus 100C, the temperature-raising heat medium pipe 58 is one of the pipes through which the heat medium flows, and is provided in the housing of the heat-medium temperature raising unit 5. One of ends of the temperature-raising heat medium pipe 58 that is close to an outlet of the heat medium flow passage in the lower heat exchanger 52 is connected to the heat medium pipe 79, and the other end of the temperature-raising heat medium pipe 58 that is close to an inlet of the heat medium flow passage in the lower heat exchanger 52 is connected to the heat medium pipe 81.
[0093] The temperature-raising control device 59 controls the operations of the expansion valve 53, the compressor 54, and the expansion valve 55. The temperature-raising control device 59 includes a processing device, dedicated hardware such as an ASIC or an FPGA, or a combination of the processing device and the dedicated hardware. The above processing device is processing device that includes a memory configured to store data and a program that are necessary for control and a CPU configured to execute the program. The temperature-raising control device 59 and the relay control device 46b perform data communication with each other to control the opening degrees of the expansion valves 42b, 53, and 55 and the driving frequencies of the pump 43b and the compressor 54 based on the results of detection by sensors, in such a manner as to cause the temperature of a heat medium that is supplied to the hot water storage tank 6 through the heat medium pipe 73 to reach a required temperature. It should be noted that the above sensors are a temperature sensor (not illustrated) configured to detect refrigerant temperature at an outlet or an inlet of the primary refrigerant flow passage of the upper heat exchanger 51, temperature sensors (not illustrated) configured to detect refrigerant temperatures at locations upstream and downstream of the compressor 54, and temperature sensors (not illustrated) configured to detect heat medium temperatures at an outlet and an inlet of the heat medium flow passage of the lower heat exchanger 52. Alternatively, the above sensors may be temperature sensors (not illustrated) configured to detect refrigerant temperatures at the outlet and inlet of the refrigerant side of the relay heat exchanger 41 b and temperature sensors (not illustrated) configured to detect heat medium temperatures at the outlet and an inlet of the heat medium side of the relay heat exchanger 41 b. In addition, in the case where the air-conditioning apparatus 100C performs the cooling operation, the relay control device 46b fixes the opening degree of the expansion valve 42b at a value at which the expansion valve 42b is fully closed.
[0094] In the refrigerant circuit 91 of Embodiment 4, the compressor 11 of the outdoor unit 1, the flow switching valve 12 of the outdoor unit 1, the outdoor heat exchanger 13 of the outdoor unit 1, the accumulator 15 of the outdoor unit 1, the refrigerant heat exchangers 21a to 21c of the refrigerant indoor units 2a to 2c, the expansion valves 22a to 22c of the refrigerant indoor units 2a to 2c, the refrigerant flow passages of the relay heat exchangers 41 a and 41 b of the relay units 4a and 4b, the expansion valves 42a and 42b of the relay units 4a and 4b, the primary refrigerant flow passage of the upper heat exchanger 51 of the heat-medium temperature raising unit 5, and the expansion valve 53 of the heat-medium temperature raising unit 5 are connected by the outdoor refrigerant pipe 16, the indoor refrigerant pipes 24a to 24c, the relay refrigerant pipes 44a and 44b, the temperature-raising primary refrigerant pipe, and the refrigerant pipes 65 and 66. The compressor 11 causes the refrigerant to circulate in the refrigerant circuit 91. It should be noted that the refrigerant circuit 91 of Embodiment 4 also corresponds to the "first refrigerant circuit" of the present disclosure, and the refrigerant that flows in the refrigerant circuit 91 corresponds to the "first refrigerant" of the present disclosure.
[0095] In the refrigerant circuit 92 of Embodiment 4, the compressor 54, the secondary refrigerant flow passage of the upper heat exchanger 51, the expansion valve 55, and the refrigerant flow passage of the lower heat exchanger 52 are connected by the temperature-raising secondary refrigerant pipe 57. The compressor 54 causes the refrigerant to circulate in the refrigerant circuit 92. It should be noted that the refrigerant circuit 92 of Embodiment 4 corresponds to the "second refrigerant circuit" of the present disclosure, and the refrigerant that flows in the refrigerant circuit 92 corresponds to the "second refrigerant" of the present disclosure. As the refrigerant that circulates in the refrigerant circuit 92, for example, R134a, R-1234yf, or R-1234ze is used. These refrigerant is different in condensing temperature from the refrigerant that circulates in the refrigerant circuit 91 and that is lower in pressure zone than the refrigerant that circulates in the refrigerant circuit 91.
[0096] In the heat medium circuit 94 of Embodiment 4, the heat medium flow passage of the relay heat exchanger 41 b of the relay unit 4b, the pump 43b of the relay unit 4b, the heat medium flow passage of the lower heat exchanger 52 of the heat-medium temperature raising unit 5, and the hot water storage tank 6 are connected by the relay heat medium pipe 45b, the temperature-raising heat medium pipe 58, and the heat medium pipes 79 to 81. The pump 43b causes the heat medium to circulate in the heat medium circuit 94. It should be noted that the heat medium circuit 94 of Embodiment 4 also corresponds to the "second heat medium circuit" of the present
disclosure.
[0097] Fig. 5 is a diagram indicating the operating points of the refrigerant circuits 91 and 92 according to Embodiment 4 on a P-h diagram. The operation of the heat-medium temperature raising unit 5 will be described with reference to Fig. 5. In Fig. 5, solid lines indicate the operating point of the refrigerant circuit 92, and dashed lines indicate the operating point of the refrigerant circuit 91. Furthermore, in Fig. 5, Tc is the condensing temperature of the refrigerant circuit 91, and Te is the evaporating temperature of the refrigerant circuit 92.
[0098] The refrigerant circuit 92 causes, with condensation heat of the refrigerant that circulates in the refrigerant circuit 91, the refrigerant that flows in the refrigerant circuit 92 to evaporate in the upper heat exchanger 51. Thus, the evaporating temperature Te of the refrigerant circuit 92 rises. Moreover, in the refrigerant circuit 92, the condensing temperature Tc of the refrigerant circuit 92 also rises because the evaporating temperature Te of the refrigerant circuit 92 rises. Thus, a balance is achieved at a supercritical pressure as indicated in Fig. 5. In a supercritical state, a latent heat change does not occur as in a normal refrigeration cycle. Therefore, when the refrigerant flows in the lower heat exchanger 52, a sensible heat change occurs in the refrigerant. In such a manner, the heat-medium temperature raising unit 5 can heat the heat medium to a high temperature.
[0099] As described above, refrigerant that is low in pressure zone, such as R134a, R1234yf, or R-1234ze, is used as the refrigerant that circulates in the refrigerant circuit 92. This eliminates a problem in pressure resistance, whereby the cost of a product can be reduced. It should be noted that the refrigerant that circulates in the refrigerant circuit 92 is not limited to the above refrigerant.
[0100] The following description concerning the flow of refrigerant in the heating operation is made by referring mainly to how the flow of refrigerant in the heating operation is different from that in Embodiment 1 while re-referring to Fig. 4. In the heating operation, high-temperature and high-pressure gas refrigerant discharged from the compressor 11 flows out from the outdoor unit 1 through the flow switching valve 12 and branch to flow into the refrigerant indoor units 2a to 2c, the relay units 4a and 4b, and the heat-medium temperature raising unit 5 through the refrigerant pipe 65.
[0101] The refrigerant that has flowed into the relay unit 4b condenses and liquefy by exchanging heat in the relay heat exchanger 41 b, with the heat medium circulated by the pump 43b. At this time, the refrigerant transfers heat to the heat medium, whereby the heat medium is heated. The refrigerant that has flowed out from the relay heat exchanger 41 b is decompressed in the expansion valve 42b, flows out from the relay unit 4b, joins in the refrigerant pipe 66, the refrigerant that has flowed out from the refrigerant indoor units 2b to 2c, and flows into the outdoor unit 1.
[0102] The refrigerant that has flowed into the heat-medium temperature raising unit 5 condenses and liquefy by exchanging heat in the primary refrigerant flow passage of the upper heat exchanger 51, with the refrigerant that flows through the secondary refrigerant flow passage. At this time, the refrigerant that circulates in the refrigerant circuit 91 transfers heat to the refrigerant that flows in the refrigerant circuit 92, whereby the refrigerant that flows in the refrigerant circuit 92 is heated. The refrigerant that has flowed out from the primary refrigerant flow passage of the upper heat exchanger 51 is decompressed in the expansion valve 53, flows out from the heat-medium temperature raising unit 5, joins in the refrigerant pipe 66, the refrigerant that has flowed out from the refrigerant indoor units 2c to 2c, and flows into the outdoor unit 1.
[0103] Furthermore, the heat medium heated in the secondary refrigerant flow passage of the upper heat exchanger 51 is sucked into the compressor 54. The refrigerant sucked into the compressor 54 is discharged in a high-temperature and high-pressure state. The high-temperature and high-pressure gas refrigerant discharged from the compressor 54 condenses and liquefy by exchanging heat in the refrigerant flow passage of the lower heat exchanger 52, with the heat medium circulated in the heat medium circuit 94 by the pump 43b. At this time, the refrigerant of the second refrigerant circuit transfers heat to the heat medium of the heat medium circuit 94, whereby the heat medium of the heat medium circuit 94 is heated to a high temperature. The refrigerant that has flowed out from the lower heat exchanger 52 is decompressed in the expansion valve 55 and flows into the upper heat exchanger 51.
[0104] Furthermore, the heat medium heated in the relay heat exchanger 41 b passes through the heat medium pipe 81 and is heated in the lower heat exchanger 52 such that its temperature reaches a higher temperature. The heat medium heated in the lower heat exchanger 52 passes through the heat medium 79 and is stored in the hot water storage tank 6. Of the heat medium stored in the hot water storage tank 6, the heat medium not supplied to the use side flows into the relay heat exchanger 41 b through the heat medium pipe 80. Thus, the heat medium supplied from the outside to the hot water storage tank 6 is heated by circulating in the heat medium circuit 94 and is then stored in the hot water storage tank 6.
[0105] In the cooling operation, in the relay unit 4b, the opening degree of the expansion valve 42b is fixed at a value at which the expansion valve 42b is fully closed. Thus, in the cooling operation, in the relay heat exchanger 41 b of the relay unit 4b, heat exchange is not substantially performed between the refrigerant circulating in the refrigerant circuit 91 and the heat medium circulating in the heat medium circuit 94. The flow of refrigerant flowing in the heat medium circuit 94 in the cooling operation is the same as that in the heating operation and its description will thus be omitted. [0106] As described above, in the air-conditioning apparatus 100C of Embodiment 4, the relay unit 4b includes the pump 43b. Thus, it is not necessary to provide a pump at any of the heat medium pipes 79 to 81. Therefore, in the air-conditioning apparatus 100C of Embodiment 4, it is not necessary to provide a pump at the time of installing the hot water storage tank 6 and it is possible to reduce the cost of on-site work.
[0107] The air-conditioning apparatus 100C of Embodiment 4 includes not only the refrigerant indoor units 2a to 2c and the hot water storage tank 6 but also the heat-medium indoor unit 3a as load-side devices. This reduces deterioration of the performance in the air-conditioning apparatus 100C as a whole. Furthermore, the heat-medium indoor unit 3a in which the heat-medium heat exchanger 31a is provided does not need to be prepared for a refrigerant leak in the indoor space. In addition, the amount of refrigerant that is contained in a sealed state in the air-conditioning apparatus can be reduced, as compared with an air-conditioning apparatus including only a refrigerant indoor unit. Therefore, the air-conditioning apparatus 100C of Embodiment 4, as the configuration of the indoor unit, it is possible to select an appropriate configuration in view of an energy-saving efficiency and whether safety measures are necessary or not.
[0108] Furthermore, the heat medium circuit 94 of the air-conditioning apparatus 100C of Embodiment 4 includes the relay heat exchanger 41 b and the lower heat exchanger 52 of the heat-medium temperature raising unit 5, which are connected in series to each other. Thus, it is possible to store in the hot water storage tank 6, a heat medium having a higher temperature than that in Embodiment 1 and supply it to the use side. In particular, since the air-conditioning apparatus 100C of Embodiment 4 includes the heat-medium temperature raising unit 5, it is possible to store in the hot water storage tank 6, a heat medium having a far higher temperature than in the case where two relay heat exchangers are connected in series to each other, and supply it to the use side. [0109] Embodiment 5 Fig. 6 is a circuit diagram of an air-conditioning apparatus 100D according to Embodiment 5. As illustrated in Fig. 6, in Embodiment 5, the air-conditioning apparatus 100D includes a heat-medium indoor unit 3b. In this regard, Embodiment 5 is different from Embodiment 4. Regarding Embodiment 5, components that are the same as those in Embodiment 4 are denoted by the same reference signs, and their descriptions will thus be omitted. The following description concerning Embodiment 5 is made by referring mainly to the differences between Embodiments 4 and 5.
[0110] The heat-medium indoor unit 3b is connected in series to the relay unit 4b, the heat-medium temperature raising unit 5, and the hot water storage tank 6. Specifically, the heat-medium temperature raising unit 5 and the hot water storage tank 6 are connected by the heat medium pipe 79 through which the heat medium flows. Furthermore, the hot water storage tank 6 and the heat-medium indoor unit 3b are connected by a heat medium pipe 82 through which the heat medium flows. Furthermore, the heat-medium indoor unit 3b and the relay unit 4b are connected by a heat medium pipe 83 through which the heat medium flows. Moreover, the relay unit 4b and the relay unit 4b are connected by the heat medium pipe 81 through which the heat medium flows.
[0111] The heat-medium indoor unit 3b is the same in configuration as the heat-medium indoor unit 3a. That is, the heat-medium indoor unit 3b includes a heat-medium heat exchanger 31 b, a flow control valve 32b, an indoor fan 33b, an indoor heat medium pipe 34b, and an indoor control device 35b. Also, components included in the heat-medium indoor unit 3b are the same in configuration as those in the heat-medium indoor unit 3a, and their descriptions will thus be omitted.
[0112] The relay heat medium pipe 45b of the relay unit 4b, the temperature-raising heat medium pipe 58 of the heat-medium temperature raising unit 5, and the indoor heat medium pipe 34b of the heat-medium indoor unit 3b are connected to the heat medium pipes 79, 81, 82, and 83 in the following manner. One of ends of the relay heat medium pipe 45b that is close to the relay heat exchanger 41b is connected to the heat medium pipe 81, and the other end of the relay heat medium pipe 45b that is close to the pump 43b is connected to the heat medium pipe 83. Furthermore, one of ends of the temperature-raising heat medium pipe 58 that is close to an outlet of the heat medium flow passage in the lower heat exchanger 52 is connected to the heat medium pipe 79, and the other end of the temperature-raising heat medium pipe 58 that is close to an inlet of the heat medium flow passage in the lower heat exchanger 52 is connected to the heat medium pipe 81. In addition, one of ends of the indoor heat medium pipe 34b that is close to the heat-medium heat exchanger 31 b is connected to the heat medium pipe 82, and the other end of the indoor heat medium pipe 34b that is close to the flow control valve 32b is connected to the heat medium pipe 83.
[0113] Thus, in the heat medium circuit 94 in Embodiment 5, the heat medium flow passage of the relay heat exchanger 41b of the relay unit 4b, the pump 43b of the relay unit 4b, the heat medium flow passage of the lower heat exchanger 52 of the heat-medium temperature raising unit 5, the hot water storage tank 6, the heat-medium heat exchanger 31 b of the heat-medium indoor unit 3b, and the flow control valve 32b of the heat-medium indoor unit 3b are connected by the relay heat medium pipe 45b, the temperature-raising heat medium pipe 58, the indoor heat medium pipe 34b, and the heat medium pipes 79 and 81 to 83. The pump 43b causes the heat medium to circulate in the heat medium circuit 94. It should be noted that the heat medium circuit 94 of Embodiment 5 also corresponds to the "second heat medium circuit" of the present disclosure.
[0114] It should be noted that the relay control device 46b and the temperature-raising control device 59 may set, as the required temperature of the heat medium, a temperature based on, for example, an instruction to the hot water storage tank 6 from the remote control or other devices and an instruction to the heat-medium indoor unit 3b from the remote control (not illustrated).
[0115] The following description concerning the flow of refrigerant in the heating operation is made by referring mainly to the differences between the flow of refrigerant in the heating operation and that in Embodiment 4. After being heated in the relay heat exchanger 41 b, the heat medium that is circulated by the pump 43b passes through the heat medium pipe 81 and is further heated in the lower heat exchanger 52. The heat medium heated in the lower heat exchanger 52 passes through the heat medium pipe 79 and is stored in the hot water storage tank 6. Of the heat medium stored in the hot water storage tank 6, the heat medium not supplied to the use side flows into the heat-medium indoor unit 3b through the heat medium pipe 82.
[0116] The heat medium that has flowed into the heat-medium indoor unit 3b exchanges heat at the heat-medium heat exchanger 31b, with air supplied by the indoor fan 33b. At this time, the heat medium transfers heat to air in an air-conditioned space, whereby the air-conditioned space in which the heat-medium indoor unit 3b is installed is heated. The heat medium that has flowed out from the heat-medium heat exchanger 31 b flows out from the heat-medium indoor unit 3b through the flow control valve 32b and flows into the relay unit 4c through the heat medium pipe 83. Thus, the heat medium supplied from the outside to the hot water storage tank 6 is heated by circulating in the heat medium circuit 94 and is stored in the hot water storage tank 6. Furthermore, the heat medium stored in the hot water storage tank 6 is primarily used in the hot water storage tank 6 and is secondarily used in the heat-medium indoor unit 3b.
[0117] As described above, in the air-conditioning apparatus 100D of Embodiment 5, the relay unit 4b includes the pump 43b. Thus, it is not necessary to provide a pump at any of the heat medium pipes 79 and 81 to 83. Therefore, in the air-conditioning apparatus 100D of Embodiment 5, it is not necessary to provide a pump at the time of installing the hot water storage tank 6 and it is possible to reduce cost of on-site work. [0118] Furthermore, the air-conditioning apparatus 100D of Embodiment 5 includes not only the refrigerant indoor units 2a to 2c and the hot water storage tank 6 but also the heat-medium indoor units 3a and 3b as load-side devices. This reduces the occurrence of an energy loss in the air-conditioning apparatus 100D as a whole. The heat-medium indoor units 3a and 3b in which the heat-medium heat exchangers 31a are provided do not need to be prepared for a refrigerant leak in the indoor space.
Furthermore, the amount of refrigerant that is contained in a sealed state in the air-conditioning apparatus can be reduced, as compared with an air-conditioning apparatus including only a refrigerant indoor unit. Thus, in the air-conditioning apparatus 100D of Embodiment 5, as the configuration of the indoor unit, it is possible to select an appropriate configuration in view of an energy-saving efficiency and whether safety measures are necessary or not.
[0119] Furthermore, the heat medium circuit 94 of the air-conditioning apparatus 100D of Embodiment 5 includes the relay heat exchanger 41 b and the lower heat exchanger 52 of the heat-medium temperature raising unit 5, which are connected in series to each other. Thus, it is possible to store in the hot water storage tank 6, a heat medium having a higher temperature than in Embodiment 1 and supply it to the use side. In particular, since the air-conditioning apparatus 100D of Embodiment 5 includes the heat-medium temperature raising unit 5, it is possible to store in the hot water storage tank 6, a heat medium having a far higher temperature than in the case where two relay heat exchangers are connected in series to each other, and supply it to the use side.
[0120] Furthermore, the heat medium circuit 94 of the air-conditioning apparatus of Embodiment 5 includes the hot water storage tank 6 and the heat-medium heat exchanger 31 b of the heat-medium indoor unit 3b. Thus, the heat medium heated by circulating in the heat medium circuit 94 can be secondarily used in the heat-medium indoor unit 3b, and the air-conditioning apparatus 100D can efficiently operate. [0121] Embodiment 6 Fig. 7 is a circuit diagram of an air-conditioning apparatus 100E according to Embodiment 6. As illustrated in Fig. 7, in Embodiment 6, the air-conditioning apparatus 100E includes a heat-medium temperature raising unit 5 instead of the relay unit 4b. In this regard, Embodiment 6 is different from Embodiment 1. Regarding Embodiment 6, components that are the same as those of Embodiment 1 will be denoted by the same reference signs, and their descriptions will thus be omitted. The following description concerning Embodiment 6 is made by referring mainly to the differences between Embodiments 1 and 6.
[0122] The outdoor unit 1 and the heat-medium temperature raising unit 5 are connected to each other by the refrigerant pipes 65 and 66 through which the refrigerant flows.
The heat-medium temperature raising unit 5 is connected to the outdoor unit 1 in parallel to the refrigerant indoor units 2a to 2c and the relay unit 4a. Furthermore, the heat-medium temperature raising unit 5 and the hot water storage tank 6 are connected by heat medium pipes 79 and 84 through which the heat medium flows. At the heat medium pipe 84, an external pump 99 is provided. That is, the external pump 99 is provided outside the heat-medium temperature raising unit 5 and the relay unit 4. The external pump 99 is, for example, an inverter centrifugal pump whose capacity can be controlled. The external pump 99 includes a motor that is driven by an inverter, and is driven by the motor, which serves as a power source. In addition, the external pump 99 applies a pressure to the heat medium that flows through the heat medium pipe 84.
[0123] The heat-medium temperature raising unit 5 is the same in configuration as the heat-medium temperature raising unit 5, which is described above regarding Embodiment 4. That is, the heat-medium temperature raising unit 5 includes an upper heat exchanger 51, a lower heat exchanger 52, an expansion valve 53, a compressor 54, an expansion valve 55, a temperature-raising primary refrigerant pipe 56, a temperature-raising secondary refrigerant pipe 57, and a temperature-raising heat medium pipe 58. Also, components included in the heat-medium temperature raising unit 5 are the same in configuration as those in the heat-medium temperature raising unit 5 as described regarding Embodiment 4, and their descriptions will thus be omitted.
[0124] The temperature-raising heat medium pipe 58 is connected to the heat medium pipes 79 and 84 in the following manner. That is, one of ends of the temperature-raising heat medium pipe 58 that adjoins an outlet of the heat medium flow passage in the lower heat exchanger 52 is connected to the heat medium pipe 79, and the other end of the temperature-raising heat medium pipe 58 that adjoins an inlet of the heat medium flow passage in the lower heat exchanger 52 is connected to the heat medium pipe 84.
[0125] The temperature-raising control device 59 controls the opening degrees of the expansion valves 53 and 55 and the driving frequencies of the external pump 99 and the compressor 54 based on the results of detection by sensors so that the temperature of a heat medium that is supplied to the hot water storage tank 6 through the heat medium pipe 79 reaches a required temperature. It should be noted that as the sensors, a temperature sensor (not illustrated) configured to detect refrigerant temperature at an outlet or an inlet of the primary refrigerant flow passage of the upper heat exchanger 51, temperature sensors (not illustrated) configured to detect respective refrigerant temperatures at locations upstream and downstream of the compressor 54, and temperature sensors (not illustrated) configured to detect respective heat medium temperatures at the outlet and inlet of the heat medium flow passage of the lower heat exchanger 52 are used.
[0126] In the refrigerant circuit 91 of Embodiment 6, the compressor 11 of the outdoor unit 1, the flow switching valve 12 of the outdoor unit 1, the outdoor heat exchanger 13 of the outdoor unit 1, the accumulator 15 of the outdoor unit 1, the refrigerant heat exchangers 21a to 21c of the refrigerant indoor units 2a to 2c, the expansion valves 22a to 22c of the refrigerant indoor units 2a to 2c, the refrigerant flow passage of the relay heat exchanger 41 a of the relay unit 4a, the expansion valve 42a of the relay unit 4a, the primary refrigerant flow passage of the upper heat exchanger 51 of the heat-medium temperature raising unit 5, and the expansion valve 53 of the heat-medium temperature raising unit 5 are connected by the outdoor refrigerant pipe 16, the indoor refrigerant pipes 24a to 24c, the relay refrigerant pipe 44a, the temperature-raising primary refrigerant pipe, and the refrigerant pipes 65 and 66. The compressor 11 causes the refrigerant to circulate in the refrigerant circuit 91. It should be noted that the refrigerant circuit 91 of Embodiment 6 also corresponds to the "first refrigerant circuit" of the present disclosure and the refrigerant that flows in the refrigerant circuit 91 corresponds to the "first refrigerant" of the present disclosure.
[0127] In the heat medium circuit 94 of Embodiment 6, the heat medium flow passage of the lower heat exchanger 52 of the heat-medium temperature raising unit 5, the hot water storage tank 6, and the external pump 99 are connected by the temperature-raising heat medium pipe 58 and the heat medium pipes 79 and 84. The external pump 99 causes the heat medium to circulate in the heat medium circuit 94. It should be noted that the heat medium circuit 94 of Embodiment 6 also corresponds to the "second heat medium circuit" of the present disclosure.
[0128] The following description concerning the flow of refrigerant in the heating operation is made by referring mainly to the differences between Embodiments 1 and 6. In the heating operation, high-temperature and high-pressure gas refrigerant discharged from the compressor 11 flows out from the outdoor unit 1 through the flow switching valve 12 and branches to flow into the refrigerant indoor units 2a to 2c, the relay unit 4a, and the heat-medium temperature raising unit 5 through the refrigerant pipe 65.
[0129] The refrigerant that has flowed into the heat-medium temperature raising unit 5 condenses and liquefy by exchanging heat in the primary refrigerant flow passage of the upper heat exchanger 51, with the refrigerant flowing through the secondary refrigerant flow passage. At this time, the refrigerant circulating in the refrigerant circuit 91 transfers heat to the refrigerant circulating in the refrigerant circuit 92, whereby the refrigerant circulating in the refrigerant circuit 92 is heated. The refrigerant that has flowed out from the primary refrigerant flow passage of the upper heat exchanger 51 is decompressed in the expansion valve 53, flows out from the heat-medium temperature raising unit 5, joins in the refrigerant pipe 66, the refrigerant that has flowed out from the refrigerant indoor units 2c to 2c, and then flows into the outdoor unit 1.
[0130] The heat medium heated in the secondary refrigerant flow passage of the upper heat exchanger 51 is sucked into the compressor 54. The refrigerant sucked into the compressor 54 is discharged in a high-temperature and high-pressure state. The high-temperature and high-pressure gas refrigerant discharged from the compressor 54 condenses and liquefies by exchanging heat in the refrigerant flow passage of the lower heat exchanger 52, with the heat medium that is caused by the compressor 54 to circulate in the heat medium circuit 94. At this time, the refrigerant of the second refrigerant circuit transfers heat to the heat medium of the heat medium circuit 94, whereby the heat medium of the heat medium circuit 94 is heated to a high temperature. The refrigerant that has flowed out from the lower heat exchanger 52 is decompressed in the expansion valve 55 and flows into the upper heat exchanger 51.
[0131] The heat medium heated in the lower heat exchanger 52 passes through the heat medium pipe 79 and is stored in the hot water storage tank 6. Of the heat medium stored in the hot water storage tank 6, the heat medium not supplied to the use side flows into the relay heat exchanger 41 b through the heat medium pipe 84. Thus, the heat medium supplied from the outside to the hot water storage tank 6 is heated by circulating through the heat medium circuit 94, and is stored in the hot water storage tank 6.
[0132] As described above, the air-conditioning apparatus 100E of Embodiment 6 includes not only the refrigerant indoor units 2a to 2c and the hot water storage tank 6 but also the heat-medium indoor unit 3a as load-side devices. This reduces the deterioration of the performance of the air-conditioning apparatus 100E as a whole.
Furthermore, the heat-medium indoor unit 3a in which the heat-medium heat exchanger 31 a is provided does not need to be prepared for a refrigerant leak in the indoor space. Furthermore, it is possible to reduce the amount of refrigerant that is contained in a sealed state in the air-conditioning apparatus, as compared with an air-conditioning apparatus including only a refrigerant indoor unit. Thus, in the air-conditioning apparatus 100E of Embodiment 6, as the configuration of the indoor unit, it is possible to select an appropriate configuration in view of an energy-saving efficiency and whether safety measures are necessary or not.
[0133] The heat medium circuit 94 of the air-conditioning apparatus 100E of Embodiment 6 includes the relay heat exchanger 41 b and the lower heat exchanger 52 of the heat-medium temperature raising unit 5, which are connected in series to each other. Thus, it is possible to store in the hot water storage tank 6, a heat medium having a higher temperature than in Embodiment 1 and supply it to the use side. In particular, since the air-conditioning apparatus 100E of Embodiment 6 includes the heat-medium temperature raising unit 5, it is possible to store, in the hot water storage tank 6, a heat medium having a far higher temperature than in the case where two relay heat exchangers are connected in series to each other, and supply it to the use side. [0134] Embodiment 7 Fig. 8 is a circuit diagram of an air-conditioning apparatus 100F according to Embodiment 7. As illustrated in Fig. 8, in Embodiment 7, the air-conditioning apparatus 100F includes a heat-medium indoor unit 3b. In this regard, Embodiment 7 is different from Embodiment 6. Regarding Embodiment 7, components that are the same as those in Embodiment 6 will be denoted by the same reference signs, and their descriptions will thus be omitted. The following description concerning Embodiment 7 is made by referring mainly to the differences between Embodiments 6 and 7.
[0135] The heat-medium indoor unit 3b is connected in series to the heat-medium temperature raising unit 5 and the hot water storage tank 6. Specifically, the heat-medium temperature raising unit 5 and the hot water storage tank 6 are connected by the heat medium pipe 79 through which the heat medium flows. Furthermore, the hot water storage tank 6 and the heat-medium indoor unit 3b are connected by a heat medium pipe 85 through which the heat medium flows. Furthermore, the heat-medium indoor unit 3b and the heat-medium temperature raising unit 5 are connected by a heat medium pipe 86 through which the heat medium flows. Furthermore, at the heat medium pipe 86, an external pump 99 is provided.
[0136] The heat-medium indoor unit 3b is the same in configuration as the heat-medium indoor unit 3a. To be more specific, the heat-medium indoor unit 3b includes a heat-medium heat exchanger 31 b, a flow control valve 32b, an indoor fan 33b, an indoor heat medium pipe 34b, and an indoor control device 35b. Components included in the heat-medium indoor unit 3b are the same in configuration as those in the heat-medium indoor unit 3a, and their descriptions will thus be omitted.
[0137] However, since the heat-medium temperature raising unit 5, the hot water storage tank 6, and the heat-medium indoor unit 3b are connected in series to each other, the temperature-raising heat medium pipe 58 of the heat-medium temperature raising unit 5 and the indoor heat medium pipe 34b of the heat-medium indoor unit 3b are connected to the heat medium pipes 79, 85, and 85 in the following manner. To be more specific, one of ends of the temperature-raising heat medium pipe 58 that is close to an outlet of the heat medium flow passage in the lower heat exchanger 52 is connected to the heat medium pipe 79, and the other end of the temperature-raising heat medium pipe 58 that is close to an inlet of the heat medium flow passage in the lower heat exchanger 52 is connected to the heat medium pipe 86. Furthermore, one of ends of the indoor heat medium pipe 34b that is close to the heat-medium heat exchanger 31 b is connected to the heat medium pipe 85, and the other end of the indoor heat medium pipe 34b that is close to the flow control valve 32b is connected to the heat medium pipe 86.
[0138] Thus, in the heat medium circuit 94 in Embodiment 7, the heat medium flow passage of the lower heat exchanger 52 of the heat-medium temperature raising unit 5, the hot water storage tank 6, the heat-medium heat exchanger 31 b of the heat-medium indoor unit 3b, and the flow control valve 32b of the heat-medium indoor unit 3b are connected by the temperature-raising heat medium pipe 58, the indoor heat medium pipe 34b, and the heat medium pipes 79, 85, and 86. The external pump 99 causes the heat medium to circulate in the heat medium circuit 94. It should be noted that the heat medium circuit 94 of Embodiment 7 also corresponds to the "second heat medium circuit" of the present disclosure.
[0139] It should be noted that the temperature-raising control device 59 of the heat-medium temperature raising unit 5 may set, as the required temperature of the heat medium, a temperature based on, for example, an instruction to the hot water storage tank 6 from the remote control or other devices and an instruction to the heat-medium indoor unit 3b from the remote control (not illustrated).
[0140] The following description concerning the flow of refrigerant in the heating operation is made by referring mainly to the difference between Embodiments 6 and 7. The heat medium that is circulated by the external pump 99 is heated in the lower heat exchanger 52, passes through the heat medium pipe 79, and is stored in the hot water storage tank 6. Of the heat medium stored in the hot water storage tank 6, the heat medium not supplied to the use side flows into the heat-medium indoor unit 3b through the heat medium pipe 85.
[0141] The heat medium that has flowed into the heat-medium indoor unit 3b exchanges heat in the heat-medium heat exchanger 31b, with air supplied by the indoor fan 33b.
At this time, the heat medium transfers heat to air in an air-conditioned space in which the heat-medium indoor unit 3b is installed, whereby the air-conditioned space is heated. The heat medium that has flowed out from the heat-medium heat exchanger 31 b flows out from the heat-medium indoor unit 3b through the flow control valve 32b and flows into the heat-medium temperature raising unit 5 through the heat medium pipe 86. Thus, the heat medium to be supplied from the outside to the hot water storage tank 6 is heated by circulating in the heat medium circuit 94, and is stored in the hot water storage tank 6. Furthermore, the heat medium stored in the hot water storage tank 6 is primarily used in the hot water storage tank 6 and is secondarily used in the heat-medium indoor unit 3b.
[0142] As described above, the air-conditioning apparatus 100F of Embodiment 7 includes not only the refrigerant indoor units 2a to 2c and the hot water storage tank 6 but also the heat-medium indoor units 3a and 3b as load-side devices. This reduces the occurrence of an energy loss in the air-conditioning apparatus 100F as a whole.
Furthermore, the heat-medium indoor units 3a and 3b in which the heat-medium heat exchangers 31a are provided do not need to be prepared for a refrigerant leak in the indoor space. Furthermore, it is possible to reduce the amount of refrigerant that is contained in a sealed state in the air-conditioning apparatus, as compared with an air- conditioning apparatus including a refrigerant indoor unit only. Thus, in the air-conditioning apparatus 100F of Embodiment 7, as the configuration of an indoor unit, it is possible to select an appropriate configuration in view of an energy-saving efficiency and whether safety measures are necessary or not.
[0143] Furthermore, the heat medium circuit 94 of the air-conditioning apparatus 100F of Embodiment 7 includes the lower heat exchanger 52 of the heat-medium temperature raising unit 5. Thus, it is possible to store in the hot water storage tank 6, a heat medium having a higher temperature than in Embodiment 1, and supply it to the use side. In particular, since the air-conditioning apparatus 100F of Embodiment 7 includes the heat-medium temperature raising unit 5, it is possible to store in the hot water storage tank 6, a heat medium having a higher temperature than in the relay heat exchanger, and supply it to the use side.
[0144] Furthermore, the heat medium circuit 94 of the air-conditioning apparatus of Embodiment 7 includes the hot water storage tank 6 and the heat-medium heat exchanger 31 b of the heat-medium indoor unit 3b. Thus, the heat medium that is heated by circulating in the heat medium circuit 94 can be secondarily used in the heat-medium indoor unit 3b, whereby the air-conditioning apparatus 100F can efficiently operate.
[0145] The above descriptions are made regarding the embodiments; however, the present disclosure is not limited to the embodiments. Various modifications of the embodiments or various combinations thereof can be made without departing from the scope of the present disclosure. For example, in each of the embodiments, although three refrigerant indoor units 2a to 2c are installed, the number of refrigerant indoor units may be 1 or 2 or may be 4 or more. Furthermore, the numbers of the refrigerant indoor units, the relay units, the hot water storage tanks, and heat-medium temperature raising units described regarding each of the embodiments are the minimum numbers required for each embodiment.
[0146] Furthermore, it is appropriate that the attachment positions of the heat medium pipes connected from the hot water storage tank to the heat-medium indoor unit 3b are adjusted in level, depending on the distribution of water temperatures obtained in the hot water storage tank or other conditions. In addition, the above descriptions concerning the embodiments refer to the case where the hot water storage tank 6 and the heat-medium indoor unit 3b are connected in series to each other. However, a refrigerant indoor unit may be connected to a secondary side of a use-side device, such as a shower or a bath that is connected to the hot water storage tank. That is, the hot water storage tank 6 and the heat-medium indoor unit 3b may be indirectly connected to each other and heat exhausted from the use-side device may be used. In this case, the use-side device requires a higher water temperature than the heat-medium indoor unit 3b.
Reference Signs List [0147] 1: outdoor unit, 2a, 2b, 2c: refrigerant indoor unit, 3a, 3b: heat-medium indoor unit, 4a, 4b, 4c: relay unit, 5 heat-medium temperature raising unit, 6: hot water storage tank, 11: compressor, 12: flow switching valve, 13: outdoor heat exchanger, 14: outdoor fan, 15: accumulator, 16: outdoor refrigerant pipe, 17: outdoor control device, 21a, 21b, 21 c: refrigerant heat exchanger, 22a, 22b, 22c: expansion valve, 23a, 23b, 23c: indoor fan, 24a, 24b, 24c: indoor refrigerant pipe, 25a, 25b, 25c: indoor control device, 31a, 31 b: heat-medium heat exchanger, 32a, 32b: flow control valve, 33a, 33b: indoor fan, 34a, 34b: indoor heat medium pipe, 35a, 35b: indoor control device, 41a, 41 b, 41c: relay heat exchanger, 42a, 42b, 42c: expansion valve, 43a, 43b, 43c: pump, 44a, 44b, 44c: relay refrigerant pipe, 45a, 45b, 45c: relay heat medium pipe, 46a, 46b, 46c: relay control device, 51: upper heat exchanger, 52: lower heat exchanger, 53: expansion valve, 54: compressor, 55: expansion valve, 56: temperature-raising primary refrigerant pipe, 57: temperature-raising secondary refrigerant pipe, 58: temperature-raising heat medium pipe, 59: temperature-raising control device, 65: refrigerant pipe, 66: refrigerant pipe, 71a: heat medium pipe, 72a: heat medium pipe, 73: heat medium pipe, 74: heat medium pipe, 75: heat medium pipe, 76: heat medium pipe, 77: heat medium pipe, 78: heat medium pipe, 79: heat medium pipe, 80: heat medium pipe, 81: heat medium pipe, 82: heat medium pipe, 83: heat medium pipe, 84: heat medium pipe, 85: heat medium pipe, 86: heat medium pipe, 91: refrigerant circuit, 92: refrigerant circuit, 93: heat medium circuit, 94: heat medium circuit, 99: external pump, 100, 100A, 100B, 100C, 100D, 100E, 100F: air-conditioning apparatus

Claims (5)

  1. CLAIMS[Claim 1] An air-conditioning apparatus comprising: an outdoor unit including a first compressor configured to cause first refrigerant to circulate in a first refrigerant circuit and an outdoor heat exchanger through which the first refrigerant flows; a refrigerant indoor unit including a refrigerant heat exchanger through which the first refrigerant flows; a first relay unit including a first pump and a first relay heat exchanger, the first pump being configured to cause a heat medium differing from the first refrigerant to circulate in a first heat medium circuit, the first relay heat exchanger being configured to cause heat exchange to be performed between the first refrigerant and the heat medium that circulates in the first heat medium circuit; a second relay unit including a second pump and a second relay heat exchanger, the second pump being configured to cause a heat medium differing from the first refrigerant to circulate in a second heat medium circuit, the second relay heat exchanger being configured to cause heat exchange to be performed between the first refrigerant and the heat medium that circulates in the second heat medium circuit; a first heat-medium indoor unit including a first heat-medium heat exchanger through which the heat medium that circulates in the first heat medium circuit flows; and a hot water storage tank in which the heat medium that circulates in the second heat medium circuit is stored.
  2. [Claim 2] The air-conditioning apparatus of claim 1, further comprising a third relay unit including a third pump configured to cause the heat medium to circulate in the second heat medium circuit and a third relay heat exchanger configured to cause heat exchange to be performed between the first refrigerant and the heat medium that circulates in the second heat medium.
  3. [Claim 3] The air-conditioning apparatus of claim 1 or 2, further comprising a heat-medium temperature raising unit including a second compressor, an upper heat exchanger, and a lower heat exchanger, the second compressor being configured to cause second refrigerant differing from both the first refrigerant and the heat medium to circulate in a second refrigerant circuit, the upper heat exchanger being configured to cause heat exchange to be performed between the first refrigerant and the second refrigerant, the lower heat exchanger being configured to cause heat exchange to be performed between the second refrigerant and the heat medium that circulates in the second heat medium circuit.
  4. [Claim 4] An air-conditioning apparatus comprising: an outdoor unit including a first compressor configured to cause first refrigerant to circulate in a first refrigerant circuit and an outdoor heat exchanger through which the first refrigerant flows; a refrigerant indoor unit including a refrigerant heat exchanger through which the first refrigerant flows; a first relay unit including a first pump and a first relay heat exchanger, the first pump being configured to cause a heat medium differing from the first refrigerant to circulate in a first heat medium circuit, the first relay heat exchanger being configured to cause heat exchange to be performed between the first refrigerant and the heat medium that circulates in the first heat medium circuit; a heat-medium temperature raising unit including a second compressor, an upper heat exchanger, and a lower heat exchanger, the second compressor being configured to cause second refrigerant differing from both the first refrigerant and the heat medium to circulate in a second refrigerant circuit, the upper heat exchanger being configured to cause heat exchange to be performed between the first refrigerant and the second refrigerant, the lower heat exchanger being configured to cause heat exchange to be performed between the second refrigerant and a heat medium that circulates in a second heat medium circuit and differs from both the first refrigerant and the second refrigerant; an external pump configured to cause the heat medium to circulate in the second heat medium circuit; a first heat-medium indoor unit including a first heat-medium heat exchanger through which the heat medium that circulates in the first heat medium circuit flows; and a hot water storage tank in which the heat medium that circulates in the second heat medium circuit is stored.
  5. [Claim 5] The air-conditioning apparatus of any one of claims 1 to 4, further comprising a second heat-medium indoor unit including a second heat-medium heat exchanger through which the heat medium that circulates in the second heat medium circuit flows.
GB2407342.1A 2021-12-23 2021-12-23 Air conditioner Pending GB2627390A (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009222246A (en) * 2008-03-13 2009-10-01 Mitsubishi Electric Corp Heat pump type water heater
JP2010196955A (en) * 2009-02-24 2010-09-09 Daikin Ind Ltd Heat pump system
WO2012077156A1 (en) * 2010-12-07 2012-06-14 三菱電機株式会社 Heat pump device
JP2013185741A (en) * 2012-03-07 2013-09-19 Rinnai Corp Heat pump type water heater

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009222246A (en) * 2008-03-13 2009-10-01 Mitsubishi Electric Corp Heat pump type water heater
JP2010196955A (en) * 2009-02-24 2010-09-09 Daikin Ind Ltd Heat pump system
WO2012077156A1 (en) * 2010-12-07 2012-06-14 三菱電機株式会社 Heat pump device
JP2013185741A (en) * 2012-03-07 2013-09-19 Rinnai Corp Heat pump type water heater

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