JPWO2014132433A1 - Air conditioner - Google Patents

Abstract

It has indoor units 2a and 2b in which two or more use side heat exchangers 26 are accommodated, and cools the heat medium by flowing a low-temperature and low-pressure heat source side refrigerant through a part of the heat exchangers 15a and 15b. Then, a cooled heat medium is supplied to a part of the use side heat exchanger 26 accommodated in the indoor units 2a and 2b, and a high temperature and a high pressure are supplied to the other part of the plurality of heat exchangers 15a and 15b. The reheat dehumidification operation mode is executed in which the heat source side refrigerant is flowed to heat the heat medium and the heated heat medium is supplied to the other part of the use side heat exchanger 26 accommodated in the indoor units 2a and 2b. It is characterized by.

Description

  The present invention relates to an air conditioner applied to, for example, a building multi-air conditioner.

  In a conventional air conditioner, one heat source unit and one indoor unit are connected by a refrigerant pipe, two heat exchangers are connected to the indoor unit via a flow control valve, and one heat exchange is performed. Some reheat (reheat) dehumidification operations are performed in which air that has been cooled and dehumidified by a vessel is mixed with air that has been heated by the other heat exchanger (see, for example, Patent Document 1).

JP 2002-89988 A (Summary, FIG. 1)

In the technique of Patent Document 1, there is a problem that the temperature of the refrigerant greatly varies depending on whether the indoor unit is operating or stopped, and the temperature and humidity of the indoor air greatly vary in the reheat dehumidifying operation.
In the reheat dehumidifying operation, it is desired that the temperature of the indoor air or the temperature and humidity of the air blown out from the indoor unit is set to a desired target value.

The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain an air conditioner that can suppress fluctuations in the temperature and humidity of room air in a reheat dehumidifying operation.
Another object of the present invention is to obtain an air conditioner capable of controlling the temperature of indoor air or the temperature and humidity of air blown out from an indoor unit in a reheat dehumidifying operation.

  An air conditioner according to the present invention includes a compressor, a heat source side heat exchanger, a plurality of expansion devices, a refrigerant side flow path of a plurality of heat exchangers between heat media, and a plurality of refrigerant flow switching devices that switch a circulation path. A refrigerant circulation circuit that circulates the heat source side refrigerant by connecting refrigerant pipes, a pump, a plurality of use side heat exchangers, a heat medium flow switching device, and a heat medium side flow path of the inter-heat medium heat exchanger A heat medium circulation circuit that circulates the heat medium by connecting the heat medium pipes, and an indoor unit in which two or more use side heat exchangers are housed, and the plurality of heat medium heat exchangers Cooling the heat medium by flowing a low-temperature and low-pressure heat-source-side refrigerant to a part thereof, supplying the cooled heat medium to a part of the use-side heat exchanger housed in the indoor unit, and Heating the heat medium by flowing a high-temperature and high-pressure heat source side refrigerant to the other part of the inter-medium heat exchanger, Some internal mechanism of another stowed the use side heat exchanger, and supplies the heat medium heated, and executes the operation mode moisture Rehito removal.

  The present invention can suppress fluctuations in the temperature and humidity of room air in a reheat dehumidifying operation.

It is the schematic which shows the example of installation of the air conditioning apparatus which concerns on embodiment of this invention. It is a refrigerant circuit structural example of the air conditioning apparatus which concerns on embodiment of this invention. It is a refrigerant circuit figure which shows the flow of the refrigerant | coolant at the time of the cooling only operation mode of the air conditioning apparatus shown in FIG. It is a refrigerant circuit figure which shows the flow of the refrigerant | coolant at the time of the heating only operation mode of the air conditioning apparatus shown in FIG. It is a refrigerant circuit diagram which shows the flow of the refrigerant | coolant at the time of the cooling main operation mode of the air conditioning apparatus shown in FIG. It is a refrigerant circuit figure which shows the flow of the refrigerant | coolant at the time of heating main operation mode of the air conditioning apparatus shown in FIG. It is a refrigerant circuit diagram which shows the flow of the refrigerant | coolant at the time of the dehumidification reheat (cooling main body) operation mode of the air conditioning apparatus shown in FIG. It is a refrigerant circuit diagram which shows the flow of the refrigerant | coolant at the time of the dehumidification reheat (heating main body) operation mode of the air conditioning apparatus shown in FIG. It is an air line figure explaining circulation amount control of a heat carrier at the time of reheat dehumidification operation mode concerning an embodiment of the invention. It is an air line figure explaining circulation amount control of a heat carrier at the time of reheat dehumidification operation mode concerning an embodiment of the invention. It is a flowchart which shows the switching operation | movement to the heat medium temperature control of the air conditioning apparatus which concerns on embodiment of this invention. It is a flowchart which shows the heat medium temperature control of the air conditioning apparatus which concerns on embodiment of this invention. It is a flowchart which shows the modification of the heat medium temperature control of the air conditioning apparatus which concerns on embodiment of this invention.

Embodiment.
FIG. 1 is a schematic diagram illustrating an installation example of an air conditioner 100 according to an embodiment of the present invention. Based on FIG. 1, the installation example of the air conditioning apparatus 100 is demonstrated. The air conditioner 100 has a refrigeration cycle for circulating refrigerant, and the indoor units 2a and 2b can freely select a cooling mode, a heating mode, or a dehumidifying reheat mode as an operation mode. The indoor unit 2b may be a type that processes the outside air taken in. The air-conditioning apparatus 100 according to the present embodiment includes, for example, a single refrigerant such as R-22, R-32, and R-134a as a refrigerant, a pseudo-azeotropic refrigerant mixture such as R-410A and R-404A, R Non-azeotropic refrigerant mixture such as −407C, a refrigerant containing a double bond in the chemical formula, such as CF ₃ CF═CH ₂ , a refrigerant with a relatively low global warming potential, or a mixture thereof, or CO ₂ or propane A refrigerant circulation circuit A (see FIG. 2) in which a natural refrigerant such as the above is adopted, and a heat medium circulation circuit B in which water or the like is adopted as a heat medium.

  Air conditioning apparatus 100 according to the present embodiment employs a system (indirect system) that indirectly uses a refrigerant (heat source side refrigerant). That is, the cold or warm heat stored in the heat source side refrigerant is transmitted to a refrigerant (hereinafter referred to as a heat medium) different from the heat source side refrigerant, and the air-conditioning target space is cooled or heated with the cold heat or heat stored in the heat medium. Alternatively, after dehumidification by the cooling function, dehumidification reheat is performed by heating.

  As illustrated in FIG. 1, an air conditioner 100 according to the present embodiment includes a single outdoor unit 1 that is a heat source unit, a plurality of indoor units 2, and an outdoor unit 1 and an indoor unit 2. And a heat medium relay unit 3 interposed therebetween. The heat medium relay unit 3 performs heat exchange between the heat source side refrigerant and the heat medium. The outdoor unit 1 and the heat medium relay unit 3 are connected by a refrigerant pipe 4 for circulating the heat source side refrigerant. The heat medium relay unit 3 and the indoor unit 2 are connected by a pipe (heat medium pipe) 5 for circulating the heat medium. The cold or warm heat generated by the outdoor unit 1 is delivered to the indoor unit 2 via the heat medium converter 3.

The outdoor unit 1 is usually disposed in an outdoor space 6 that is a space outside a building 9 such as a building (for example, a rooftop), and supplies cold or hot heat to the indoor unit 2 via the heat medium converter 3. It is.
The indoor unit 2 is disposed at a position where cooling air or heating air can be supplied to the indoor space 7 which is a space (for example, a living room) inside the building 9, and is used for cooling the indoor space 7 serving as a space to be air-conditioned. Air or heating air is supplied.
The heat medium relay unit 3 is installed at a position different from the outdoor space 6 and the indoor space 7 as a separate housing from the outdoor unit 1 and the indoor unit 2. The heat medium converter 3 is connected to the outdoor unit 1 and the indoor unit 2 via the refrigerant pipe 4 and the pipe 5, respectively, and transmits cold heat or hot heat supplied from the outdoor unit 1 to the indoor unit 2. is there.

  As shown in FIG. 1, in the air conditioning apparatus 100 according to the present embodiment, the outdoor unit 1 and the heat medium converter 3 are connected via two refrigerant pipes 4, and the heat medium converter 3. And the indoor units 2a and 2b are connected via four pipes 5 respectively. As described above, in the air conditioner 100 according to Embodiment 1, each unit (the outdoor unit 1, the indoor unit 2, and the heat medium converter 3) is connected by way of the refrigerant pipe 4 and the pipe 5, thereby performing the construction. Is easy.

  In FIG. 1, the heat medium converter 3 is inside the building 9 but is a space other than the indoor space 7 such as a ceiling (for example, a space such as a ceiling behind the building 9, hereinafter, It is illustrated by way of example as being installed in a space 8). The heat medium relay 3 may be installed in a common space where there is an elevator or the like. Moreover, in FIG. 1, although the indoor unit 2 has shown the ceiling embedded type as an example, it is not limited to this. That is, the air conditioner 100 can be of any kind as long as it is capable of blowing heating air or cooling air directly or through a duct or the like into the ceiling cassette type, ceiling suspended type, or indoor space 7. Good. You may also take in outside air.

  Further, the heat medium relay unit 3 can be installed in the vicinity of the outdoor unit 1. However, it should be noted that if the distance from the heat medium relay unit 3 to the indoor unit 2 is too long, the power for transporting the heat medium becomes considerably large, and the energy saving effect is diminished.

FIG. 2 is a refrigerant circuit configuration example of the air-conditioning apparatus 100 according to the embodiment of the present invention.
As shown in FIG. 2, the outdoor unit 1 and the heat medium relay 3 are connected to the refrigerant pipe 4 via the heat exchanger related to heat medium 15 a and the heat exchanger related to heat medium 15 b provided in the heat medium converter 3. Connected with. The heat medium relay unit 3 and the indoor unit 2 are also connected by a pipe 5. The refrigerant pipe 4 will be described in detail later.

[Outdoor unit 1]
The outdoor unit 1 stores a compressor 10 that compresses refrigerant, a first refrigerant flow switching device 11 that includes a four-way valve, a heat source side heat exchanger 12 that functions as an evaporator or a condenser, and excess refrigerant. An accumulator 19 is connected to and mounted on the refrigerant pipe 4.
The outdoor unit 1 is also provided with a first connection pipe 4a, a second connection pipe 4b, a check valve 13a, a check valve 13b, a check valve 13c, and a check valve 13d. Regardless of the operation that the indoor unit 2 requires, the heat medium is provided by providing the first connection pipe 4a, the second connection pipe 4b, the check valve 13a, the check valve 13b, the check valve 13c, and the check valve 13d. The flow of the heat source side refrigerant flowing into the converter 3 can be in a certain direction.

The compressor 10 sucks the heat source side refrigerant and compresses the heat source side refrigerant into a high temperature and high pressure state. For example, the compressor 10 may be composed of an inverter compressor capable of capacity control.
The first refrigerant flow switching device 11 has a flow of the heat source side refrigerant in the heating operation mode (in the heating only operation mode and the heating main operation mode) and in the cooling operation mode (in the all cooling operation mode and the cooling main operation mode). ) To switch the flow of the heat source side refrigerant.
The heat source side heat exchanger 12 functions as an evaporator during heating operation, functions as a condenser during cooling operation, and performs heat exchange between air supplied from a blower such as a fan (not shown) and the heat source side refrigerant. Is.

  The accumulator 19 is provided on the suction side of the compressor 10. Further, a second pressure sensor 37 and a third pressure sensor 38, which are pressure detection devices, are provided before and after the compressor 10, and the rotation speed of the compressor 10, the second pressure sensor 37, and the third pressure sensor 38 are The refrigerant flow rate from the compressor 10 can be calculated from the detected value.

[Indoor unit 2]
Two usage-side heat exchangers 26 are mounted on each indoor unit 2. In the example of FIG. 2, the case where two indoor units 2 are connected to the heat medium relay unit 3 is illustrated as an example, and the indoor unit 2a and the indoor unit 2b are illustrated from the bottom of the drawing. Note that the number of connected indoor units 2 is not limited to two. The indoor unit 2a is an indoor air suction type that sucks indoor air, harmonizes the air, and blows it out indoors. The indoor unit 2a is equipped with a use side heat exchanger 26a and a use side heat exchanger 26b. The indoor unit 2b is an outside air suction type that takes in outdoor air and harmonizes it with air, and then blows it out into the room. The indoor unit 2b is equipped with a use side heat exchanger 26c and a use side heat exchanger 26d. The use side heat exchanger 26a and the use side heat exchanger 26c perform cooling or dehumidification. The use side heat exchanger 26b and the use side heat exchanger 26d perform heating or reheat heating operation.

  The use side heat exchanger 26 is connected to the heat medium flow control device 25 and the second heat medium flow switching device 23 of the heat medium converter 3 by the pipe 5. The use-side heat exchanger 26 performs heat exchange between air supplied from a blower such as a fan and a heat medium, and also controls heating air or cooling air supplied to the indoor space 7 with humidity management. It is generated including.

  The indoor unit 2a that is an indoor air suction type is provided with an intake air temperature sensor 39 that detects the temperature of the indoor air sucked into the indoor unit 2a, and an intake air humidity sensor 40 that detects the humidity of the indoor air. . The outdoor air suction type indoor unit 2b is provided with a blown air temperature sensor 41 for detecting the temperature of the air blown from the indoor unit 2b and a blown air humidity sensor 42 for detecting the humidity of the air blown from the indoor unit 2b.

[Heat medium converter 3]
The heat medium relay 3 opens and closes two heat medium heat exchangers 15 a and 15 b that exchange heat between the refrigerant and the heat medium, two expansion devices 16 a and 16 b that depressurize the refrigerant, and a refrigerant pipe 4. Two opening / closing devices 17a, 17b, two second refrigerant flow switching devices 18a, 18b for switching the refrigerant flow channel, two pumps 21a, 12b for circulating the heat medium, and four firsts connected to one of the pipes 5 Heat medium flow path switching devices 22a to 22d, four second heat medium flow path switching devices 23a to 23d connected to the other of the pipe 5, and the pipe to which the first heat medium flow path switching device 22 is connected Four heat medium flow control devices 25 a to 25 d connected to 5 are provided.

  The two heat exchangers 15a and 15b (sometimes referred to as the heat exchanger 15) function as a condenser (heat radiator) or an evaporator, and exchange heat between the heat source side refrigerant and the heat medium. And the cold or warm heat generated in the outdoor unit 1 and stored in the heat source side refrigerant is transmitted to the heat medium. The heat exchanger related to heat medium 15a is provided between the expansion device 16a and the second refrigerant flow switching device 18a in the refrigerant circuit A and serves to cool the heat medium in the cooling / heating mixed operation mode. is there. The heat exchanger related to heat medium 15b is provided between the expansion device 16b and the second refrigerant flow switching device 18b in the refrigerant circuit A and serves to heat the heat medium in the cooling / heating mixed operation mode. is there.

  The two expansion devices 16a and 16b (sometimes referred to as expansion devices 16) have functions as pressure reducing valves and expansion valves, and expand the heat source side refrigerant by reducing the pressure. The expansion device 16a is provided on the upstream side of the heat exchanger related to heat medium 15a in the flow of the heat source side refrigerant in the cooling only operation mode. The expansion device 16b is provided on the upstream side of the heat exchanger related to heat medium 15b in the flow of the heat source side refrigerant in the cooling only operation mode. The two expansion devices 16 may be configured by a device whose opening degree can be variably controlled, for example, an electronic expansion valve.

  The opening / closing devices 17a, 17b are constituted by two-way valves or the like, and open / close the refrigerant pipe 4.

  The two second refrigerant flow switching devices 18a and 18b (sometimes referred to as the second refrigerant flow switching device 18) are composed of four-way valves or the like, and switch the flow of the heat source side refrigerant according to the operation mode. is there. The second refrigerant flow switching device 18a is provided on the downstream side of the heat exchanger related to heat medium 15a in the flow of the heat source side refrigerant in the cooling only operation mode. The second refrigerant flow switching device 18b is provided on the downstream side of the heat exchanger related to heat medium 15b in the flow of the heat source side refrigerant in the cooling only operation mode.

  Two pumps 21 a and 21 b (also referred to as pump 21) circulate the heat medium in the pipe 5. The pump 21 a is provided in the pipe 5 between the heat exchanger related to heat medium 15 a and the second heat medium flow switching device 23. The pump 21 b is provided in the pipe 5 between the heat exchanger related to heat medium 15 b and the second heat medium flow switching device 23. The two pumps 21 may be constituted by, for example, pumps capable of capacity control. The pump 21a may be provided in the pipe 5 between the heat exchanger related to heat medium 15a and the first heat medium flow switching device 22. Further, the pump 21b may be provided in the pipe 5 between the heat exchanger related to heat medium 15b and the first heat medium flow switching device 22.

  The four first heat medium flow switching devices 22a to 22d (sometimes referred to as the first heat medium flow switching device 22) are configured by a three-way valve or the like, and switch the flow path of the heat medium. . The first heat medium flow switching device 22 is provided with a number (four in this case) corresponding to twice the number of indoor units 2a and 2b installed. In the first heat medium flow switching device 22, one of the three sides is in the heat exchanger 15a, one of the three is in the heat exchanger 15b, and one of the three is in the heat medium flow rate. Each is connected to the adjusting device 25 and provided on the outlet side of the heat medium flow path of the use side heat exchanger 26a. The first heat medium from the lower side of the drawing corresponds to the use side heat exchanger 26a and the use side heat exchanger 26b of the indoor unit 2a and the use side heat exchanger 26c and the use side heat exchanger 26d of the indoor unit 2b. The flow path switching devices 22a, 22b, 22c, and 22d are illustrated. In addition, the first heat medium flow switching devices 22a, 22b, 22c, and 22d are illustrated to be installed in the heat medium converter 3, but the number may be larger.

  The four second heat medium flow switching devices 23a to 23d (sometimes referred to as the second heat medium flow switching device 23) are configured by a three-way valve or the like, and switch the flow path of the heat medium. . The number of the second heat medium flow switching devices 23 is set according to the number of installed indoor units 2 (here, four). In the second heat medium flow switching device 23, one of the three heat transfer medium heat exchangers 15a, one of the three heat transfer medium heat exchangers 15b, and one of the three heat transfer side heats. It is connected to the exchanger (or heat recovery heat exchanger) 26 and provided on the inlet side of the heat medium flow path of the use side heat exchanger (or heat recovery heat exchanger) 26. It should be noted that the second heat medium from the lower side of the drawing corresponds to the use side heat exchanger 26a and the use side heat exchanger 26b of the indoor unit 2a and the use side heat exchanger 26c and the use side heat exchanger 26d of the indoor unit 2b. The flow path switching devices 23a, 23b, 23c, and 23d are illustrated. In addition, the second heat medium flow switching devices 23a, 23b, 23c, and 23d are illustrated as being installed in the heat medium converter 3, but the number may be larger.

The four heat medium flow control devices 25a to 25d (sometimes referred to as heat medium flow control devices 25) are configured by two-way valves or the like that can control the opening area, and adjust the flow rate of the heat medium flowing through the pipe 5. To do. The number of the heat medium flow control devices 25 is set according to the number of indoor units 2 installed (four in this case). One of the heat medium flow control devices 25 is connected to the use side heat exchanger 26, and the other is connected to the first heat medium flow switching device 22, so that the use side heat exchanger (or heat recovery heat exchanger) 26 is connected. It is provided on the outlet side of the heat medium flow path. It should be noted that the heat medium flow rate adjustment is performed from the lower side of the drawing to correspond to the use side heat exchanger 26a and the use side heat exchanger 26b of the indoor unit 2a, and the use side heat exchanger 26c and the use side heat exchanger 26d of the indoor unit 2b Illustrated as devices 25a, 25b, 25c, 25d. Further, although the heat medium flow control devices 25a, 25b, 25c, and 25d are illustrated as being installed in the heat medium converter 3, a larger number may be used.
Further, the heat medium flow control device 25 may be provided on the inlet side of the heat medium flow path of the use side heat exchanger 26.

  The heat medium relay 3 includes various detection means (two first temperature sensors 31a and 31b, four second temperature sensors 34a to 34d, four third temperature sensors 35a to 35d, and one fourth temperature sensor. 50, a first pressure sensor 36) is provided. Information (for example, temperature information and pressure information) detected by these detection means is sent to a control device that performs overall control of the operation of the air conditioner 100, and the driving frequency of the compressor 10, the heat source side heat exchanger 12 and The rotation speed of the blower provided near the use side heat exchanger (or heat recovery heat exchanger) 26, switching of the first refrigerant flow switching device 11, switching frequency of the pump 21, switching of the second refrigerant flow switching device 18 It is used for control such as switching of the flow path of the heat medium.

  The control device (not shown) is configured by a microcomputer or the like, and calculates the evaporation temperature, the condensation temperature, the saturation temperature, the superheat degree, and the supercooling degree based on the calculation result of the arithmetic device 52. Then, the control device, based on these calculation results, includes the opening degree of the expansion device 16, the rotational speed of the compressor 10, and the fan speed (including ON / OFF) of the heat source side heat exchanger 12 and the use side heat exchanger 26. ) And the like so that the performance of the air conditioner 100 is maximized. In addition, the control device, based on detection information from various detection means and instructions from the remote controller, the driving frequency of the compressor 10, the rotational speed of the blower (including ON / OFF), the first refrigerant flow switching device 11 Switching, driving of the pump 21, opening of the expansion device 16, opening and closing of the switching device 17, switching of the second refrigerant channel switching device 18, switching of the first heat medium channel switching device 22, switching of the second heat medium channel The switching of the device 23 and the opening degree of the heat medium flow control device 25 are controlled. That is, the control device performs overall control of various devices in order to execute each operation mode described later. The control device is also provided in the outdoor unit 1, and controls the actuator of the outdoor unit 1 based on information transmitted from the control device of the heat medium relay unit 3. Moreover, although the control apparatus of the heat medium relay machine 3 is demonstrated as what is different from the arithmetic unit 57, it may be the same body.

  The two first temperature sensors 31 a and 31 b (also referred to as the first temperature sensor 31) are the heat medium flowing out from the intermediate heat exchanger 15, that is, the heat medium at the outlet of the intermediate heat exchanger 15. The temperature is detected, and for example, a thermistor may be used. The first temperature sensor 31a is provided in the pipe 5 on the inlet side of the pump 21a. The first temperature sensor 31b is provided in the pipe 5 on the inlet side of the pump 21b.

  Four second temperature sensors 34a to 34d (sometimes referred to as second temperature sensors 34) are provided between the first heat medium flow switching device 22 and the heat medium flow control device 25, and use side heat exchange. The temperature of the heat medium flowing out from the vessel 26 is detected, and it may be constituted by a thermistor or the like. The number of the second temperature sensors 34 (four here) according to the number of indoor units 2 installed is provided. It should be noted that the second temperature sensor from the lower side of the drawing corresponds to the use side heat exchanger 26a and the use side heat exchanger 26b of the indoor unit 2a and the use side heat exchanger 26c and the use side heat exchanger 26d of the indoor unit 2b. It is shown as 34a, 34b, 34c, 34d.

  The four third temperature sensors 35a to 35d (also referred to as the third temperature sensor 35) are provided on the inlet side or the outlet side of the heat source side refrigerant of the heat exchanger related to heat medium 15 and are used as heat exchangers related to the heat medium. The temperature of the heat source side refrigerant flowing into the heat source 15 or the temperature of the heat source side refrigerant flowing out of the heat exchanger related to heat medium 15 is detected, and may be composed of a thermistor or the like. The third temperature sensor 35a is provided between the heat exchanger related to heat medium 15a and the second refrigerant flow switching device 18a. The third temperature sensor 35b is provided between the heat exchanger related to heat medium 15a and the expansion device 16a. The third temperature sensor 35c is provided between the heat exchanger related to heat medium 15b and the second refrigerant flow switching device 18b. The third temperature sensor 35d is provided between the heat exchanger related to heat medium 15b and the expansion device 16b.

  The fourth temperature sensor 50 obtains temperature information used when calculating the evaporation temperature and the dew point temperature, and is provided between the expansion device 16a and the expansion device 16b.

  The pipe 5 for circulating the heat medium is composed of one connected to the heat exchanger related to heat medium 15a and one connected to the heat exchanger related to heat medium 15b. The pipe 5 is branched (here, four branches each) according to twice the number of indoor units 2 connected to the heat medium relay unit 3. The pipe 5 is connected by a first heat medium flow switching device 22 and a second heat medium flow switching device 23. By controlling the first heat medium flow switching device 22 and the second heat medium flow switching device 23, the heat medium from the heat exchanger related to heat medium 15a flows into the use-side heat exchanger 26, or the heat medium Whether the heat medium from the intermediate heat exchanger 15b flows into the use side heat exchanger 26 is determined.

[Description of operation mode]
The air conditioner 100 includes a compressor 10, a first refrigerant flow switching device 11, a heat source side heat exchanger 12, a switching device 17, a second refrigerant flow switching device 18, and a refrigerant flow channel of the heat exchanger related to heat medium 15a. The expansion device 16 and the accumulator 19 are connected by the refrigerant pipe 4 to constitute the refrigerant circulation circuit A. Further, the heat medium flow path of the heat exchanger related to heat medium 15a, the pump 21, the first heat medium flow switching device 22, the heat medium flow control device 25, the use side heat exchanger 26, and the second heat medium flow path. The switching device 23 is connected by a pipe 5 to constitute a heat medium circulation circuit B. That is, a plurality of usage-side heat exchangers 26 are connected in parallel to each of the heat exchangers between heat media 15, and the heat medium circulation circuit B has a plurality of systems. In addition, in this Embodiment, the utilization side heat exchanger 26 is divided into the utilization side heat exchangers 26a and 26c for cooling or dehumidification, and the utilization side heat exchangers 26b and 26d for heating or reheat heating. It is divided.

  Therefore, in the air conditioner 100, the outdoor unit 1 and the heat medium relay unit 3 are connected via the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b provided in the heat medium converter 3. The heat medium converter 3 and the indoor unit 2 are connected via the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b. That is, in the air conditioner 100, the heat source side refrigerant circulating in the refrigerant circuit A and the heat medium circulating in the heat medium circuit B exchange heat in the intermediate heat exchanger 15a and the intermediate heat exchanger 15b. It is like that.

  Each operation mode which the air conditioning apparatus 100 performs is demonstrated. The air conditioner 100 can perform a cooling operation, a heating operation, or a dehumidifying reheat operation in the indoor unit 2 based on an instruction from each indoor unit 2. That is, the air conditioner 100 can perform the same operation for all the indoor units 2, can perform different operations for each of the indoor units 2, and can also perform a dehumidifying reheat operation.

  The operation mode executed by the air conditioner 100 includes a cooling only operation mode in which all the driven indoor units 2 execute a cooling operation, and a heating only operation in which all the driven indoor units 2 execute a heating operation. There are a cooling main operation mode as a cooling / heating mixed operation mode with a larger mode and a cooling load, and a heating main operation mode as a cooling / heating mixed operation mode with a larger heating load. In addition, there are a dehumidification reheat operation (cooling main body) that is in the same operation state as the cooling main body, and a dehumidification reheat operation (heating main body) that is in the same operation state as the heating main body. Below, each operation mode is demonstrated with the flow of a heat-source side refrigerant | coolant and a heat medium.

[Cooling operation mode]
FIG. 3 is a refrigerant circuit diagram illustrating a refrigerant flow when the air-conditioning apparatus 100 illustrated in FIG. 2 is in the cooling only operation mode. In FIG. 3, the cooling only operation mode will be described by taking as an example a case where a cooling load is generated in the indoor unit 2a and the indoor unit 2b. In addition, in FIG. 3, the piping represented with the thick line has shown the piping through which a refrigerant | coolant (a heat source side refrigerant | coolant and a heat medium) flows. In FIG. 3, the flow direction of the heat source side refrigerant is indicated by a solid line arrow, and the flow direction of the heat medium is indicated by a broken line arrow.

  In the cooling only operation mode shown in FIG. 3, in the outdoor unit 1, the first refrigerant flow switching device 11 is switched so that the heat source side refrigerant discharged from the compressor 10 flows into the heat source side heat exchanger 12. In the heat medium relay 3, the pumps 21 a and 21 b are driven, the heat medium flow control devices 25 a and 25 c are opened, the heat medium flow control devices 25 b and 25 d are closed, and the heat exchanger related to heat medium 15 a and the heat medium are connected. A heat medium circulates between each of the heat exchangers 15b and the use side heat exchangers 26a and 26c.

First, the flow of the heat source side refrigerant in the refrigerant circuit A will be described.
The low-temperature and low-pressure refrigerant is compressed by the compressor 10 and discharged as a high-temperature and high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows into the heat source side heat exchanger 12 via the first refrigerant flow switching device 11. And it becomes a high-pressure liquid refrigerant, radiating heat to outdoor air with the heat source side heat exchanger 12. The high-pressure refrigerant that has flowed out of the heat source side heat exchanger 12 flows out of the outdoor unit 1 through the check valve 13 a, and flows into the heat medium relay unit 3 through the refrigerant pipe 4. The high-pressure refrigerant flowing into the heat medium relay unit 3 is branched after passing through the opening / closing device 17a and is expanded by the expansion device 16a and the expansion device 16b to become a low-temperature low-pressure two-phase refrigerant. The opening / closing device 17b is closed.

  This two-phase refrigerant flows into each of the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b acting as an evaporator, and absorbs heat from the heat medium circulating in the heat medium circulation circuit B. It becomes a low-temperature and low-pressure gas refrigerant while cooling. The gas refrigerant that has flowed out of the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b flows out of the heat medium converter 3 via the second refrigerant flow switching device 18a and the second refrigerant flow switching device 18b. Then, the refrigerant flows into the outdoor unit 1 again through the refrigerant pipe 4. The refrigerant flowing into the outdoor unit 1 passes through the check valve 13d and is sucked into the compressor 10 again via the first refrigerant flow switching device 11 and the accumulator 19.

  At this time, the second refrigerant flow switching device 18a and the second refrigerant flow switching device 18b are in communication with the low pressure pipe. Further, the opening degree of the expansion device 16a is controlled so that the superheat (superheat degree) obtained as a difference between the temperature detected by the third temperature sensor 35a and the temperature detected by the third temperature sensor 35b becomes constant. Is done. Similarly, the opening degree of the expansion device 16b is controlled so that the superheat obtained as the difference between the temperature detected by the third temperature sensor 35c and the temperature detected by the third temperature sensor 35d is constant.

Next, the flow of the heat medium in the heat medium circuit B will be described.
In the cooling only operation mode, the cold heat of the heat source side refrigerant is transmitted to the heat medium in both the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b, and the cooled heat medium is piped 5 by the pump 21a and the pump 21b. The inside will be allowed to flow. The heat medium pressurized and discharged by the pump 21a and the pump 21b passes through the second heat medium flow switching device 23a and the second heat medium flow switching device 23c, and the use side heat exchanger 26a and the use side heat exchange. Flow into the vessel 26c. The heat medium absorbs heat from the indoor air in the use side heat exchanger 26a and the use side heat exchanger 26c, thereby cooling the indoor space 7.

  Then, the heat medium flows out of the use side heat exchanger 26a and the use side heat exchanger 26c and flows into the heat medium flow control device 25a and the heat medium flow control device 25c. At this time, the heat medium flow rate adjusting device 25a and the heat medium flow rate adjusting device 25c control the flow rate of the heat medium to a flow rate necessary to cover the air conditioning load required indoors. And it flows into the use side heat exchanger 26c. The heat medium flowing out from the heat medium flow control device 25a and the heat medium flow control device 25c passes through the first heat medium flow switching device 22a and the first heat medium flow switching device 22c, and the heat exchanger related to heat medium 15a. And flows into the heat exchanger related to heat medium 15b, and is sucked into the pump 21a and the pump 21b again.

  In the pipes 5 of the use side heat exchangers 26a and 26c, heat is generated in a direction from the second heat medium flow switching device 23 to the first heat medium flow switching device 22 via the heat medium flow control device 25. The medium is flowing. The air conditioning load required in the indoor space 7 is detected by the temperature detected by the first temperature sensor 31a, or the temperature detected by the first temperature sensor 31b and the second temperature sensor 34a or 34c. This can be covered by controlling so as to keep the difference from the temperature as a target value. As the outlet temperature of the heat exchanger related to heat medium 15, either the temperature of the first temperature sensor 31a or the first temperature sensor 31b may be used, or the average temperature thereof may be used. At this time, the first heat medium flow switching device 22 and the second heat medium flow switching device 23 ensure a flow path that flows to both the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b. In addition, the intermediate opening is set.

  When the cooling only operation mode is executed, it is not necessary to flow the heat medium to the use side heat exchanger 26 (including the thermo-off) without the heat load. The heat medium is prevented from flowing to the heat exchanger 26. In FIG. 3, the use-side heat exchangers 26 a and 26 c have a heat load, and thus a heat medium flows. However, the use-side heat exchangers 26 b and 26 d dedicated to heating and reheat heating do not operate, and thus correspond. The heat medium flow control device 25b and the heat medium flow control device 25d are fully closed. However, when the use side heat exchangers 26b and 26d are used for cooling, the heat medium flow control device 25 may be opened to circulate the heat medium.

  The refrigerant in the fourth temperature sensor 50 is a liquid refrigerant, and the liquid inlet enthalpy is calculated by the arithmetic unit 52 based on this temperature information. Further, the temperature of the low-pressure two-phase temperature state is detected from the third temperature sensor 35d, and the saturated liquid enthalpy and the saturated gas enthalpy are calculated by the arithmetic unit 52 based on this temperature information. Based on these information, the evaporation temperature and the dew point temperature are obtained by the method described later.

[Heating operation mode]
FIG. 4 is a refrigerant circuit diagram showing a refrigerant flow when the air-conditioning apparatus 100 shown in FIG. 2 is in the heating only operation mode. In FIG. 4, the heating only operation mode will be described by taking as an example a case where a thermal load is generated in the indoor unit 2a and the indoor unit 2b. In FIG. 4, the pipes indicated by the thick lines indicate the pipes through which the refrigerant flows. In FIG. 4, the flow direction of the heat source side refrigerant is indicated by solid line arrows, and the flow direction of the heat medium is indicated by broken line arrows.

  In the heating only operation mode shown in FIG. 4, in the outdoor unit 1, the first refrigerant flow switching device 11 causes the heat source side refrigerant discharged from the compressor 10 to heat without passing through the heat source side heat exchanger 12. It switches so that it may flow into the media converter 3. In the heat medium relay unit 3, the pump 21a and the pump 21b are driven, the heat medium flow control devices 25b and 25d are opened, the heat medium flow control devices 25a and 25c are closed, and the heat exchanger related to heat medium 15a and the heat medium are closed. The heat medium is circulated between each of the intermediate heat exchangers 15b and the use side heat exchangers 26b and 26d.

First, the flow of the heat source side refrigerant in the refrigerant circuit A will be described.
The low-temperature and low-pressure refrigerant is compressed by the compressor 10 and discharged as a high-temperature and high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows out of the outdoor unit 1 through the first refrigerant flow switching device 11 and the check valve 13b. The high-temperature and high-pressure gas refrigerant that has flowed out of the outdoor unit 1 flows into the heat medium relay unit 3 through the refrigerant pipe 4. The high-temperature and high-pressure gas refrigerant that has flowed into the heat medium relay unit 3 is branched and passes through the second refrigerant flow switching device 18a and the second refrigerant flow switching device 18b, so that the heat exchanger related to heat medium 15a and the heat medium are heated. It flows into each of the heat exchangers 15b.

  The high-temperature and high-pressure gas refrigerant flowing into the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b becomes a high-pressure liquid refrigerant while radiating heat to the heat medium circulating in the heat medium circuit B. The liquid refrigerant flowing out of the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b is expanded by the expansion device 16a and the expansion device 16b to become a low-temperature and low-pressure two-phase refrigerant. The two-phase refrigerant flows out of the heat medium relay unit 3 through the opening / closing device 17b, and flows into the outdoor unit 1 through the refrigerant pipe 4 again. The opening / closing device 17a is closed.

  The refrigerant that has flowed into the outdoor unit 1 flows through the check valve 13c and into the heat source side heat exchanger 12 that functions as an evaporator. And the refrigerant | coolant which flowed into the heat source side heat exchanger 12 absorbs heat from outdoor air in the heat source side heat exchanger 12, and becomes a low-temperature low-pressure gas refrigerant. The low-temperature and low-pressure gas refrigerant flowing out from the heat source side heat exchanger 12 is again sucked into the compressor 10 via the first refrigerant flow switching device 11 and the accumulator 19.

  At this time, the second refrigerant flow switching device 18a and the second refrigerant flow switching device 18b are in communication with the high-pressure pipe. Further, in the expansion device 16a, the subcool (degree of subcooling) obtained as a difference between the value detected by the first pressure sensor 36 and the temperature detected by the third temperature sensor 35b is constant. The opening degree is controlled so that Similarly, the expansion device 16b opens so that a subcool obtained as a difference between a value obtained by converting the pressure detected by the first pressure sensor 36 into a saturation temperature and a temperature detected by the third temperature sensor 35d is constant. The degree is controlled. If the temperature at the intermediate position of the heat exchanger related to heat medium 15 can be measured, the temperature at the intermediate position may be used instead of the first pressure sensor 36, and the system can be configured at low cost.

Next, the flow of the heat medium in the heat medium circuit B will be described.
In the heating only operation mode, the heat of the heat source side refrigerant is transmitted to the heat medium in both the heat exchanger 15a and the heat exchanger 15b, and the heated heat medium is piped 5 by the pump 21a and the pump 21b. The inside will be allowed to flow. The heat medium that has been pressurized and discharged by the pump 21a and the pump 21b passes through the second heat medium flow switching device 23b and the second heat medium flow switching device 23d, and then the use side heat exchanger 26b and the use side heat exchange. Flow into the vessel 26d. The heat medium radiates heat to the indoor air by the use side heat exchanger 26b and the use side heat exchanger 26d, thereby heating the indoor space 7.

  Then, the heat medium flows out from the use side heat exchanger 26b and the use side heat exchanger 26d and flows into the heat medium flow control device 25b and the heat medium flow control device 25d. At this time, the heat medium flow control device 25b and the heat medium flow control device 25d control the flow rate of the heat medium to a flow rate necessary to cover the air conditioning load required in the room, so that the use-side heat exchanger 26b. And it flows into the use side heat exchanger 26d. The heat medium flowing out of the heat medium flow control device 25b and the heat medium flow control device 25d passes through the first heat medium flow switching device 22b and the first heat medium flow switching device 22d, and the heat exchanger related to heat medium 15a. And flows into the heat exchanger related to heat medium 15b, and is sucked into the pump 21a and the pump 21b again.

  In the pipe 5 of the use side heat exchanger 26, the heat medium is directed from the second heat medium flow switching device 23 to the first heat medium flow switching device 22 via the heat medium flow control device 25. Flowing. The air conditioning load required in the indoor space 7 is detected by the temperature detected by the first temperature sensor 31a, the temperature detected by the first temperature sensor 31b, and the second temperature sensors 34b and 34d. By controlling so as to keep the difference from the temperature as a target value, it can be covered. As the outlet temperature of the heat exchanger related to heat medium 15, either the temperature of the first temperature sensor 31a or the first temperature sensor 31b may be used, or the average temperature thereof may be used.

  At this time, the first heat medium flow switching device 22 and the second heat medium flow switching device 23 ensure a flow path that flows to both the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b. In addition, the intermediate opening is set. In addition, the usage-side heat exchanger 26 should be controlled by the temperature difference between the inlet and the outlet, but the temperature of the heat medium on the inlet side of the usage-side heat exchanger 26 is detected by the first temperature sensor 31b. By using the first temperature sensor 31b, the number of temperature sensors can be reduced and the system can be configured at low cost.

  When the heating only operation mode is executed, it is not necessary to flow the heat medium to the use side heat exchanger 26 (including the thermo-off) without the heat load. The heat medium is prevented from flowing to the heat exchanger 26. In FIG. 4, a heat medium flows because the use-side heat exchangers 26 b and 26 d have a heat load, but the use-side heat exchangers 26 a and 26 c dedicated to cooling and dehumidification do not operate, so the corresponding heat The medium flow rate adjusting device 25a and the heat medium flow rate adjusting device 25c are fully closed. However, when the use side heat exchangers 26a and 26c dedicated to cooling and dehumidification are used for heating, the heat medium flow control device 25 may be opened to circulate the heat medium.

[Cooling operation mode]
FIG. 5 is a refrigerant circuit diagram showing a refrigerant flow when the air-conditioning apparatus 100 shown in FIG. 2 is in the cooling main operation mode. In FIG. 5, the cooling main operation mode will be described by taking as an example a case where a thermal load is generated in the indoor unit 2b and a cooling load is generated in the indoor unit 2a. Note that in FIG. 5, a pipe represented by a thick line shows a pipe through which the refrigerant (heat source side refrigerant and heat medium) circulates. Further, in FIG. 5, the flow direction of the heat source side refrigerant is indicated by solid line arrows, and the flow direction of the heat medium is indicated by broken line arrows.

  In the cooling main operation mode shown in FIG. 5, in the outdoor unit 1, the first refrigerant flow switching device 11 is switched so that the heat source side refrigerant discharged from the compressor 10 flows into the heat source side heat exchanger 12. In the heat medium converter 3, the pump 21a and the pump 21b are driven, the heat medium flow control devices 25a and 25d are opened, and the space between the heat exchanger 15a and the use side heat exchanger 26a is between the heat medium. The heat medium circulates between the heat exchanger 15b and the use side heat exchanger 26d.

First, the flow of the heat source side refrigerant in the refrigerant circuit A will be described.
The low-temperature and low-pressure refrigerant is compressed by the compressor 10 and discharged as a high-temperature and high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows into the heat source side heat exchanger 12 via the first refrigerant flow switching device 11. And it becomes a liquid refrigerant, dissipating heat to outdoor air with the heat source side heat exchanger 12. The refrigerant that has flowed out of the heat source side heat exchanger 12 flows out of the outdoor unit 1 and flows into the heat medium relay unit 3 through the check valve 13 a and the refrigerant pipe 4. The refrigerant that has flowed into the heat medium relay unit 3 flows into the heat exchanger related to heat medium 15b that acts as a condenser through the second refrigerant flow switching device 18b.

  The refrigerant that has flowed into the heat exchanger related to heat medium 15b becomes a refrigerant whose temperature is further lowered while dissipating heat to the heat medium circulating in the heat medium circuit B. The refrigerant flowing out of the heat exchanger related to heat medium 15b is expanded by the expansion device 16b and becomes a low-pressure two-phase refrigerant. This low-pressure two-phase refrigerant flows into the heat exchanger related to heat medium 15a acting as an evaporator via the expansion device 16a. The low-pressure two-phase refrigerant that has flowed into the heat exchanger related to heat medium 15a absorbs heat from the heat medium circulating in the heat medium circuit B, and becomes a low-pressure gas refrigerant while cooling the heat medium. The gas refrigerant flows out of the heat exchanger related to heat medium 15a, flows out of the heat medium converter 3 via the second refrigerant flow switching device 18a, and flows into the outdoor unit 1 again through the refrigerant pipe 4. The refrigerant that has flowed into the outdoor unit 1 is again sucked into the compressor 10 via the check valve 13d, the first refrigerant flow switching device 11, and the accumulator 19.

  At this time, the second refrigerant flow switching device 18a is in communication with the low pressure pipe, while the second refrigerant flow switching device 18b is in communication with the high pressure side piping. Further, the opening degree of the expansion device 16b is controlled so that the superheat obtained as the difference between the temperature detected by the third temperature sensor 35a and the temperature detected by the third temperature sensor 35b becomes constant. Further, the expansion device 16a is fully opened, and the opening / closing devices 17a and 17b are closed. The expansion device 16b has an opening degree so that a subcool obtained as a difference between a value obtained by converting the pressure detected by the first pressure sensor 36 into a saturation temperature and a temperature detected by the third temperature sensor 35d is constant. May be controlled. Alternatively, the expansion device 16b may be fully opened, and the superheat or subcool may be controlled by the expansion device 16a.

Next, the flow of the heat medium in the heat medium circuit B will be described.
In the cooling main operation mode, the heat of the heat source side refrigerant is transmitted to the heat medium in the heat exchanger related to heat medium 15b, and the heated heat medium is caused to flow in the pipe 5 by the pump 21b. In the cooling main operation mode, the cold heat of the heat source side refrigerant is transmitted to the heat medium by the heat exchanger related to heat medium 15a, and the cooled heat medium is caused to flow in the pipe 5 by the pump 21a.

  In the use side heat exchanger 26d, the heat medium radiates heat to the indoor air, thereby heating the indoor space 7. In the use-side heat exchanger 26a, the indoor space 7 is cooled by the heat medium absorbing heat from the indoor air. At this time, the flow rate of the heat medium is controlled to a flow rate necessary to cover the air conditioning load required indoors by the action of the heat medium flow control devices 25a and 25d, and flows into the use side heat exchangers 26a and 26d. It is like that. The heat medium whose temperature has slightly decreased after passing through the use side heat exchanger 26d flows into the heat exchanger related to heat medium 15b through the heat medium flow control device 25d and the first heat medium flow switching device 22d, and again. It is sucked into the pump 21b. The heat medium whose temperature has slightly increased after passing through the use side heat exchanger 26a flows into the heat exchanger related to heat medium 15a through the heat medium flow control device 25a and the first heat medium flow switching device 22a, and again. It is sucked into the pump 21a.

  During this time, the warm heat medium and the cold heat medium are not mixed by the action of the first heat medium flow switching device 22 and the second heat medium flow switching device 23, and the use side has a heat load and a heat load, respectively. It introduce | transduces into the heat exchanger 26a, 26d. In addition, in the piping 5 of the use side heat exchangers 26a and 26d, the first heat medium flow switching is performed from the second heat medium flow switching device 23 via the heat medium flow control device 25 on both the heating side and the cooling side. A heat medium flows in the direction to the device 22. In addition, the air conditioning load required in the indoor space 7 is the difference between the temperature detected by the first temperature sensor 31b on the heating side and the temperature detected by the second temperature sensor 34 on the heating side. This can be covered by controlling the difference between the temperature detected by the two-temperature sensor 34 and the temperature detected by the first temperature sensor 31a as a target value.

  When executing the cooling main operation mode, it is not necessary to flow the heat medium to the use side heat exchanger 26 (including the thermo-off) without the heat load, so the flow path is closed by the heat medium flow control device 25 and the use side The heat medium is prevented from flowing to the heat exchanger 26. In FIG. 5, the use side heat exchangers 26 b and 26 c without a heat load close the heat medium flow control device 25.

[Heating main operation mode]
FIG. 6 is a refrigerant circuit diagram illustrating a refrigerant flow when the air-conditioning apparatus 100 illustrated in FIG. 2 is in the heating main operation mode. In FIG. 6, the heating main operation mode will be described by taking as an example a case where a thermal load is generated in the indoor unit 2b and a cooling load is generated in the indoor unit 2a. In addition, in FIG. 6, the piping represented with the thick line has shown the piping through which a refrigerant | coolant (a heat-source side refrigerant | coolant and a heat medium) circulates. In FIG. 6, the flow direction of the heat source side refrigerant is indicated by solid line arrows, and the flow direction of the heat medium is indicated by broken line arrows.

  In the heating-main operation mode shown in FIG. 6, in the outdoor unit 1, the first refrigerant flow switching device 11 uses the heat source side refrigerant discharged from the compressor 10 without passing through the heat source side heat exchanger 12. It switches so that it may flow into converter 3. In the heat medium converter 3, the pump 21a and the pump 21b are driven, the heat medium flow control devices 25a and 25d are opened, and the space between the heat exchanger 15a and the use side heat exchanger 26a is between the heat medium. The heat medium circulates between the heat exchanger 15b and the use side heat exchanger 26d.

First, the flow of the heat source side refrigerant in the refrigerant circuit A will be described.
The low-temperature and low-pressure refrigerant is compressed by the compressor 10 and discharged as a high-temperature and high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows out of the outdoor unit 1 through the first refrigerant flow switching device 11 and the check valve 13b. The high-temperature and high-pressure gas refrigerant that has flowed out of the outdoor unit 1 flows into the heat medium relay unit 3 through the refrigerant pipe 4. The high-temperature and high-pressure gas refrigerant that has flowed into the heat medium relay unit 3 flows into the heat exchanger related to heat medium 15b that acts as a condenser through the second refrigerant flow switching device 18b.

  The gas refrigerant that has flowed into the heat exchanger related to heat medium 15b becomes liquid refrigerant while dissipating heat to the heat medium circulating in the heat medium circuit B. The refrigerant flowing out of the heat exchanger related to heat medium 15b is expanded by the expansion device 16b and becomes a low-pressure two-phase refrigerant. This low-pressure two-phase refrigerant flows into the heat exchanger related to heat medium 15a acting as an evaporator via the expansion device 16a. The low-pressure two-phase refrigerant that has flowed into the heat exchanger related to heat medium 15a evaporates by absorbing heat from the heat medium circulating in the heat medium circuit B, thereby cooling the heat medium. The low-pressure two-phase refrigerant flows out of the heat exchanger related to heat medium 15a, flows out of the heat medium converter 3 through the second refrigerant flow switching device 18a, and flows into the outdoor unit 1 again.

  The refrigerant that has flowed into the outdoor unit 1 flows through the check valve 13c and into the heat source side heat exchanger 12 that functions as an evaporator. And the refrigerant | coolant which flowed into the heat source side heat exchanger 12 absorbs heat from outdoor air in the heat source side heat exchanger 12, and becomes a low-temperature low-pressure gas refrigerant. The low-temperature and low-pressure gas refrigerant flowing out from the heat source side heat exchanger 12 is again sucked into the compressor 10 via the first refrigerant flow switching device 11 and the accumulator 19.

  At this time, the second refrigerant flow switching device 18a communicates with the low-pressure side piping, while the second refrigerant flow switching device 18b communicates with the high-pressure side piping. The expansion device 16b has an opening degree so that a subcool obtained as a difference between a value obtained by converting the pressure detected by the first pressure sensor 36 into a saturation temperature and a temperature detected by the third temperature sensor 35b is constant. Is controlled. Further, the expansion device 16a is fully opened, and the opening / closing devices 17a and 17b are closed. Note that the expansion device 16b may be fully opened, and the subcooling may be controlled by the expansion device 16a.

Next, the flow of the heat medium in the heat medium circuit B will be described.
In the heating main operation mode, the heat of the heat source side refrigerant is transmitted to the heat medium in the heat exchanger related to heat medium 15b, and the heated heat medium is caused to flow in the pipe 5 by the pump 21b. In the heating main operation mode, the cold heat of the heat source side refrigerant is transmitted to the heat medium by the heat exchanger related to heat medium 15a, and the cooled heat medium is caused to flow in the pipe 5 by the pump 21a. The heat medium pressurized and discharged by the pump 21a and the pump 21b flows into the use side heat exchangers 26a and 26d through the second heat medium flow switching device 23a and the second heat medium flow switching device 23d. .

  In the use side heat exchanger 26a, the heat medium absorbs heat from the indoor air, thereby cooling the indoor space 7. In the use side heat exchanger 26d, the heat medium radiates heat to the indoor air, thereby heating the indoor space 7. At this time, the heat medium flow control device 25a and the heat medium flow control device 25d control the flow rate of the heat medium to a flow rate necessary to cover the air conditioning load required in the room, so that the use-side heat exchanger 26a. , 26d. The heat medium that has passed through the use-side heat exchanger 26a and whose temperature has risen slightly passes through the heat medium flow control device 25a and the first heat medium flow switching device 22a, flows into the heat exchanger related to heat medium 15a, and again It is sucked into the pump 21a. The heat medium whose temperature has slightly decreased after passing through the use side heat exchanger 26d flows into the heat exchanger related to heat medium 15b through the heat medium flow control device 25d and the first heat medium flow switching device 22d, and again. It is sucked into the pump 21b.

  During this time, the warm heat medium and the cold heat medium are not mixed by the action of the first heat medium flow switching device 22 and the second heat medium flow switching device 23, and the use side has a heat load and a heat load, respectively. It is introduced into the heat exchanger 26a or 26d. In addition, in the piping 5 of the use side heat exchangers 26a and 26d, the first heat medium flow switching is performed from the second heat medium flow switching device 23 via the heat medium flow control device 25 on both the heating side and the cooling side. A heat medium flows in the direction to the device 22. In addition, the air conditioning load required in the indoor space 7 is the difference between the temperature detected by the first temperature sensor 31b on the heating side and the temperature detected by the second temperature sensor 34 on the heating side. This can be covered by controlling the difference between the temperature detected by the two-temperature sensor 34 and the temperature detected by the first temperature sensor 31a as a target value.

  When the heating main operation mode is executed, it is not necessary to flow the heat medium to the use side heat exchanger 26 (including the thermo-off) without the heat load, so the flow path is closed by the heat medium flow control device 25 and the use side The heat medium is prevented from flowing to the heat exchanger 26. In FIG. 6, the use side heat exchangers 26 b and 26 c having no heat load close all the heat medium flow control devices 25.

[Reheat dehumidification operation (cooling mainly) mode]
FIG. 7 is a refrigerant circuit diagram illustrating a refrigerant flow in the reheat dehumidifying operation (cooling main) mode of the air-conditioning apparatus 100 illustrated in FIG. 2. In FIG. 7, the reheat dehumidifying operation (cooling main) mode will be described by taking as an example the case where the indoor unit 2a adjusts the indoor humidity and the indoor temperature and the indoor unit 2b adjusts the blowout humidity and the blowout temperature. In FIG. 7, a pipe represented by a thick line shows a pipe through which the refrigerant (heat source side refrigerant and heat medium) circulates. In FIG. 7, the flow direction of the heat source side refrigerant is indicated by solid line arrows, and the flow direction of the heat medium is indicated by broken line arrows.

In the reheat dehumidifying operation (cooling main) mode shown in FIG. 7, in the outdoor unit 1, the first refrigerant flow switching device 11 causes the heat source side refrigerant discharged from the compressor 10 to flow into the heat source side heat exchanger 12. Switch as follows. In the heat medium relay unit 3, the pump 21a and the pump 21b are driven, and the heat medium flow control devices 25a to 25d are opened.
Further, the first heat medium flow switching devices 22a and 22c and the second heat medium flow switching devices 23a and 23c are switched to the flow channels on the heat exchanger related to heat medium 15a, and used with the heat exchanger related to heat medium 15a. A heat medium is circulated between the side heat exchangers 26a and 26c. The first heat medium flow switching devices 22b and 22d and the second heat medium flow switching devices 23b and 23d are replaced with flow channels on the heat exchanger related to heat medium 15b, so that the heat exchanger related to heat medium 15b and the use side are replaced. A heat medium is circulated between the heat exchangers 26b and 26d.

First, the flow of the heat source side refrigerant in the refrigerant circuit A will be described.
The low-temperature and low-pressure refrigerant is compressed by the compressor 10 and discharged as a high-temperature and high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows into the heat source side heat exchanger 12 via the first refrigerant flow switching device 11. And it becomes a liquid refrigerant, dissipating heat to outdoor air with the heat source side heat exchanger 12. The refrigerant that has flowed out of the heat source side heat exchanger 12 flows out of the outdoor unit 1 and flows into the heat medium relay unit 3 through the check valve 13 a and the refrigerant pipe 4. The refrigerant that has flowed into the heat medium relay unit 3 flows into the heat exchanger related to heat medium 15b that acts as a condenser through the second refrigerant flow switching device 18b.

  The refrigerant that has flowed into the heat exchanger related to heat medium 15b becomes a refrigerant whose temperature is further lowered while dissipating heat to the heat medium circulating in the heat medium circuit B. The refrigerant flowing out of the heat exchanger related to heat medium 15b is expanded by the expansion device 16b and becomes a low-pressure two-phase refrigerant. This low-pressure two-phase refrigerant flows into the heat exchanger related to heat medium 15a acting as an evaporator via the expansion device 16a. The low-pressure two-phase refrigerant that has flowed into the heat exchanger related to heat medium 15a absorbs heat from the heat medium circulating in the heat medium circuit B, and becomes a low-pressure gas refrigerant while cooling the heat medium. The gas refrigerant flows out of the heat exchanger related to heat medium 15a, flows out of the heat medium converter 3 via the second refrigerant flow switching device 18a, and flows into the outdoor unit 1 again through the refrigerant pipe 4. The refrigerant that has flowed into the outdoor unit 1 is again sucked into the compressor 10 via the check valve 13d, the first refrigerant flow switching device 11, and the accumulator 19.

At this time, the second refrigerant flow switching device 18a is in communication with the low pressure pipe, while the second refrigerant flow switching device 18b is in communication with the high pressure side piping. The expansion device 16a is fully open, and the opening / closing devices 17a and 17b are closed.
The opening of the expansion device 16b is controlled based on a target condensation temperature and a target evaporation temperature described later. Alternatively, the expansion device 16b opens so that the superheat (SH) obtained as the difference between the temperature detected by the third temperature sensor 35a and the temperature detected by the third temperature sensor 35b becomes a target value described later. The degree is controlled. Further, the expansion device 16b has a subcool (SC) obtained as a difference between a value detected by the first pressure sensor 36 converted to a saturation temperature and a temperature detected by the third temperature sensor 35d, and a target value. The opening degree is controlled so that Details will be described later. Alternatively, the expansion device 16b may be fully opened, and the superheat or subcool may be controlled by the expansion device 16a.

Next, the flow of the heat medium in the heat medium circuit B will be described.
In the reheat dehumidifying operation (cooling mainly) mode, the heat of the heat source side refrigerant is transmitted to the heat medium by the heat exchanger 15b between the heat medium, and the heated heat medium is caused to flow in the pipe 5 by the pump 21b. Further, in the reheat dehumidifying operation (cooling main) mode, the cold heat of the heat source side refrigerant is transmitted to the heat medium by the heat exchanger 15a between the heat medium, and the cooled heat medium is caused to flow in the pipe 5 by the pump 21a. Become.

In the usage-side heat exchanger 26a, the heat medium absorbs heat from the room air, thereby reducing the indoor humidity and temperature. And in the utilization side heat exchanger 26b, the heat medium radiates heat to the indoor air, thereby adjusting the room temperature of the indoor space 7 lowered by the utilization side heat exchanger 26a. As a result, the temperature and humidity of the room air are adjusted.
Further, in the use side heat exchanger 26c, the humidity and temperature of the intake air are lowered by absorbing heat from the outside air taken in by the heat medium. Then, in the use side heat exchanger 26d, the heat medium radiates heat to the indoor air, thereby adjusting the intake outside air lowered in the use side heat exchanger 26c and adjusting the blowing temperature. As a result, the temperature and humidity of the air blown from the indoor unit 2b are adjusted.

At this time, the heat medium flow control devices 25a to 25d control the flow rate of the heat medium to a flow rate necessary to cover the air conditioning load or dehumidification capacity required in the room, and use side heat exchangers 26a to 26d. To flow into. Details will be described later.
The heat medium that has passed through the use-side heat exchangers 26b and 26d and has been slightly lowered in temperature passes through the heat medium flow control devices 25b and 25d and the first heat medium flow switching devices 22b and 22d, and then the heat exchanger between heat mediums 15b flows into the pump 21b again. The heat medium that has passed through the use side heat exchangers 26a and 26c and slightly increased in temperature passes through the heat medium flow control devices 25a and 25c and the first heat medium flow switching devices 22a and 22c, and then the heat exchanger between heat mediums. It flows into 15a and is sucked into the pump 21a again.

During this time, the warm heat medium and the cold heat medium are not mixed with each other by the action of the first heat medium flow switching device 22 and the second heat medium flow switching device 23, respectively, and the heat load (reheat load) and the heat load are respectively reduced. (Dehumidification load) is introduced into a use side heat exchanger 26a-26d. In the piping 5 of the use side heat exchangers 26a to 26d, both the heating side (reheat side) and the cooling side (dehumidification side) are routed from the second heat medium flow switching device 23 via the heat medium flow control device 25. Thus, the heat medium flows in the direction reaching the first heat medium flow switching device 22.
The air conditioning load (dehumidification load and reheat load) required in the indoor space 7 is the difference between the temperature detected by the first temperature sensor 31b and the temperature detected by the second temperature sensor 34 on the heating side. However, it can be covered by controlling the heat medium flow control device 25 so that the target temperature difference ΔTm. On the cooling side, the heat medium flow control device 25 is controlled so that the difference between the temperature detected by the second temperature sensor 34 and the temperature detected by the first temperature sensor 31a becomes the target temperature difference ΔTm. This can be covered. Details will be described later.

  In addition, in FIG. 7, since there is no utilization side heat exchanger 26 without a thermal load, all the heat medium flow control devices 25 are open, but the present invention is not limited to this. When executing the reheat dehumidifying operation (cooling mainly) mode, it is not necessary to flow the heat medium to the indoor unit 2 (including the thermo-off) without the heat load. The heat medium is prevented from flowing to the side heat exchanger 26.

[Reheat dehumidification operation (heating mainly) mode]
FIG. 8 is a refrigerant circuit diagram illustrating a refrigerant flow during the reheat dehumidifying operation (heating main) of the air-conditioning apparatus 100 illustrated in FIG. 2. In FIG. 8, the reheat dehumidifying operation (heating main) mode will be described by taking as an example the case where the indoor unit 2a adjusts the indoor humidity and the indoor temperature, and the indoor unit 2b adjusts the blowout humidity and the blowout temperature. In FIG. 8, a pipe represented by a thick line shows a pipe through which the refrigerant (heat source side refrigerant and heat medium) circulates. In FIG. 8, the flow direction of the heat source side refrigerant is indicated by solid line arrows, and the flow direction of the heat medium is indicated by broken line arrows.

In the reheat dehumidifying operation (heating mainly) mode shown in FIG. 8, in the outdoor unit 1, the first refrigerant flow switching device 11 causes the heat source side refrigerant discharged from the compressor 10 to flow into the heat source side heat exchanger 12. Switch as follows. In the heat medium relay unit 3, the pump 21a and the pump 21b are driven, and the heat medium flow control devices 25a to 25d are opened.
Further, the first heat medium flow switching devices 22a and 22c and the second heat medium flow switching devices 23a and 23c are switched to the flow channels on the heat exchanger related to heat medium 15a, and used with the heat exchanger related to heat medium 15a. A heat medium is circulated between the side heat exchangers 26a and 26c. The first heat medium flow switching devices 22b and 22d and the second heat medium flow switching devices 23b and 23d are switched to the flow channels on the heat exchanger related to heat medium 15b, so that the heat exchanger related to heat medium 15b and the use side heat are switched. A heat medium is circulated between the exchangers 26b and 26d.

First, the flow of the heat source side refrigerant in the refrigerant circuit A will be described.
The low-temperature and low-pressure refrigerant is compressed by the compressor 10 and discharged as a high-temperature and high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows out of the outdoor unit 1 through the first refrigerant flow switching device 11 and the check valve 13b. The high-temperature and high-pressure gas refrigerant that has flowed out of the outdoor unit 1 flows into the heat medium relay unit 3 through the refrigerant pipe 4. The high-temperature and high-pressure gas refrigerant that has flowed into the heat medium relay unit 3 flows into the heat exchanger related to heat medium 15b that acts as a condenser through the second refrigerant flow switching device 18b.

  The gas refrigerant that has flowed into the heat exchanger related to heat medium 15b becomes liquid refrigerant while dissipating heat to the heat medium circulating in the heat medium circuit B. The refrigerant flowing out of the heat exchanger related to heat medium 15b is expanded by the expansion device 16b and becomes a low-pressure two-phase refrigerant. This low-pressure two-phase refrigerant flows into the heat exchanger related to heat medium 15a acting as an evaporator via the expansion device 16a. The low-pressure two-phase refrigerant that has flowed into the heat exchanger related to heat medium 15a evaporates by absorbing heat from the heat medium circulating in the heat medium circuit B, thereby cooling the heat medium. The low-pressure two-phase refrigerant flows out of the heat exchanger related to heat medium 15a, flows out of the heat medium converter 3 through the second refrigerant flow switching device 18a, and flows into the outdoor unit 1 again.

  The refrigerant that has flowed into the outdoor unit 1 flows through the check valve 13c and into the heat source side heat exchanger 12 that functions as an evaporator. And the refrigerant | coolant which flowed into the heat source side heat exchanger 12 absorbs heat from outdoor air in the heat source side heat exchanger 12, and becomes a low-temperature low-pressure gas refrigerant. The low-temperature and low-pressure gas refrigerant flowing out from the heat source side heat exchanger 12 is again sucked into the compressor 10 via the first refrigerant flow switching device 11 and the accumulator 19.

At this time, the second refrigerant flow switching device 18a communicates with the low-pressure side piping, while the second refrigerant flow switching device 18b communicates with the high-pressure side piping. The expansion device 16a is fully open, and the opening / closing devices 17a and 17b are closed.
The opening of the expansion device 16b is controlled based on a target condensation temperature and a target evaporation temperature described later. Alternatively, the expansion device 16b opens so that the superheat (SH) obtained as the difference between the temperature detected by the third temperature sensor 35a and the temperature detected by the third temperature sensor 35b becomes a target value described later. The degree is controlled. Further, the expansion device 16b has a subcool (SC) obtained as a difference between a value detected by the first pressure sensor 36 converted to a saturation temperature and a temperature detected by the third temperature sensor 35d, and a target value. The opening degree is controlled so that Details will be described later. Alternatively, the expansion device 16b may be fully opened, and the superheat or subcool may be controlled by the expansion device 16a.

Next, the flow of the heat medium in the heat medium circuit B will be described.
In the reheat dehumidifying operation (heating mainly) mode, the heat of the heat source side refrigerant is transmitted to the heat medium by the heat exchanger 15b between the heat medium, and the heated heat medium is caused to flow in the pipe 5 by the pump 21b. Further, in the reheat dehumidifying operation (cooling main) mode, the cold heat of the heat source side refrigerant is transmitted to the heat medium by the heat exchanger 15a between the heat medium, and the cooled heat medium is caused to flow in the pipe 5 by the pump 21a. Become.

In the usage-side heat exchanger 26a, the heat medium absorbs heat from the room air, thereby reducing the indoor humidity and temperature. And in the utilization side heat exchanger 26b, the heat medium radiates heat to the indoor air, thereby adjusting the room temperature of the indoor space 7 lowered by the utilization side heat exchanger 26a. As a result, the temperature and humidity of the room air are adjusted.
Further, in the use side heat exchanger 26c, the humidity and temperature of the intake air are lowered by absorbing heat from the outside air taken in by the heat medium. Then, in the use side heat exchanger 26d, the heat medium radiates heat to the indoor air, thereby adjusting the intake outside air lowered in the use side heat exchanger 26c and adjusting the blowing temperature. As a result, the temperature and humidity of the air blown from the indoor unit 2b are adjusted.

At this time, the heat medium flow control devices 25a to 25d control the flow rate of the heat medium to a flow rate necessary to cover the air conditioning load or dehumidification capacity required in the room, and use side heat exchangers 26a to 26d. To flow into. Details will be described later.
The heat medium that has passed through the use-side heat exchangers 26b and 26d and has been slightly lowered in temperature passes through the heat medium flow control devices 25b and 25d and the first heat medium flow switching devices 22b and 22d, and then the heat exchanger between heat mediums 15b flows into the pump 21b again. The heat medium that has passed through the use side heat exchangers 26a and 26c and slightly increased in temperature passes through the heat medium flow control devices 25a and 25c and the first heat medium flow switching devices 22a and 22c, and then the heat exchanger between heat mediums. It flows into 15a and is sucked into the pump 21a again.

During this time, the warm heat medium and the cold heat medium are not mixed with each other by the action of the first heat medium flow switching device 22 and the second heat medium flow switching device 23, respectively, and the heat load (reheat load) and the heat load are respectively reduced. (Dehumidification load) is introduced into a use side heat exchanger 26a-26d. In the piping 5 of the use side heat exchangers 26a to 26d, both the heating side (reheat side) and the cooling side (dehumidification side) are routed from the second heat medium flow switching device 23 via the heat medium flow control device 25. Thus, the heat medium flows in the direction reaching the first heat medium flow switching device 22.
The air conditioning load (dehumidification load and reheat load) required in the indoor space 7 is the difference between the temperature detected by the first temperature sensor 31b and the temperature detected by the second temperature sensor 34 on the heating side. However, it can be covered by controlling the heat medium flow control device 25 so that the target temperature difference ΔTm. On the cooling side, the heat medium flow control device 25 is controlled so that the difference between the temperature detected by the second temperature sensor 34 and the temperature detected by the first temperature sensor 31a becomes the target temperature difference ΔTm. This can be covered. Details will be described later.

  In addition, in FIG. 8, since there is no utilization side heat exchanger 26 without a thermal load, all the heat medium flow control devices 25 are open, but the present invention is not limited to this. When the reheat dehumidifying operation (heating mainly) mode is executed, it is not necessary to flow the heat medium to the indoor unit 2 (including the thermo-off) that has no heat load. The heat medium is prevented from flowing to the side heat exchanger 26.

As described above, the heat-source-side refrigerant in the refrigerant circuit A serving as the primary loop exchanges heat with the heat medium in the heat medium circuit B serving as the secondary loop, and the use-side heat exchanger 26 through which the cooled heat medium flows. The reheat dehumidifying operation is performed in which the air dehumidified by the air is mixed with the air heated by the use-side heat exchanger 26 through which the heated heat medium flows and blown out.
For this reason, temperature fluctuations of the heat medium are alleviated, and fluctuations in the temperature and humidity of the indoor air can be suppressed. Therefore, the indoor temperature and humidity become stable, and the indoor comfort can be improved.

[Control of heat medium circulation rate]
Next, the flow control of the heat medium in the reheat dehumidification operation (heating main) mode and the reheat dehumidification operation (cooling main) mode (also collectively referred to as reheat dehumidification operation mode) will be described.

[Control of indoor unit 2a which is an indoor air suction type]
First, the control of the indoor unit 2a which is an indoor air suction type will be described with reference to FIG.
FIG. 9 is an air line diagram for explaining the heat medium circulation rate control in the reheat dehumidifying operation mode according to the embodiment of the present invention. FIG. 9A is an air diagram illustrating a target temperature difference ΔTm of the use side heat exchanger 26a (hereinafter also referred to as a main side heat exchanger). FIG. 9B is an air diagram illustrating a target temperature difference ΔTm of the use side heat exchanger 26b (hereinafter also referred to as a reheat side heat exchanger).

[Main heat exchanger]
As shown in FIG. 9A, an air line indicating the correlation between the temperature and humidity of air according to the difference between the temperature and humidity of the air sucked into the indoor unit 2a and the target temperature Xm and the target humidity Ym. Divide the figure into multiple regions. And target temperature difference (DELTA) Tm (heat exchange capability) is preset for every some area | region. For example, when the detected value of the intake air temperature sensor 39 is X and the detected value of the intake air humidity sensor 40 is Y, the temperature ranges are X-Xm ≧ 1 ° C., 1> X-Xm ≧ −1 ° C., X− It is divided into three ranges of Xm <−1 ° C. Further, the humidity range is divided into three ranges: Y−Ym ≧ 5%, 5%> Y−Ym ≧ −5%, and Y−Ym <−5%. And it divides | segments into nine area | regions which combined each of the temperature range and the humidity range. In this example, the humidity is relative humidity detection.

  A target temperature difference ΔTm (heat exchange capability) (1) to (4) is set in advance in each of the nine regions. Here, for example, (1) is set to target temperature difference ΔTm = 2, (2) is set to target temperature difference ΔTm = 3, (3) is set to target temperature difference ΔTm = 5, and (4) is set to target temperature difference ΔTm = 7. Is done. Thus, the target temperature difference ΔTm of the main-side heat exchanger is set larger as the temperature of the sucked air is higher and the humidity is higher. In the example of FIG. 9A, the air diagram is divided into nine regions, but the present invention is not limited to this and may be divided into any number.

  The control device opens the opening (opening) of the heat medium flow control device 25a so that the difference between the temperature detected by the first temperature sensor 31a and the temperature detected by the second temperature sensor 34a becomes the target temperature difference ΔTm. Area). That is, when the difference between the temperature of the heat medium before flowing into the main heat exchanger and the temperature of the heat medium after flowing out of the main heat exchanger is larger than the target temperature difference ΔTm, the heat exchanging capacity Is increased, the opening degree of the heat medium flow control device 25a is increased. On the other hand, if the difference between the temperature of the heat medium before flowing into the main heat exchanger and the temperature of the heat medium after flowing out of the main heat exchanger is smaller than the target temperature difference ΔTm, the heat exchanging capacity In order to decrease the opening degree of the heat medium flow control device 25a.

  In addition, when the temperature of the air sucked into the indoor unit 2a is smaller than the target temperature Xm by a predetermined value or more, circulation of the heat medium may be stopped to prevent an excessive temperature decrease. For example, when the control device detects X−Xm <−5, the heat medium flow control device 25a is fully closed.

[Reheat-side heat exchanger]
As shown in FIG. 9B, the air diagram is divided into a plurality of regions according to the difference between the temperature of the air sucked into the indoor unit 2a and the target temperature Xm. And target temperature difference (DELTA) Tm (heat exchange capability) is preset for every some area | region. For example, when the detected value of the intake air temperature sensor 39 is X, the temperature ranges are 0.5> X−Xm ≧ −1, −1> X−Xm ≧ −2, and X−Xm <−2. Separate into two ranges.

  A target temperature difference ΔTm (heat exchange capability) (1) to (3) is set in advance in each of the three regions. Here, for example, (1) is set to the target temperature difference ΔTm = 2, (2) is set to the target temperature difference ΔTm = 4, and (3) is set to the target temperature difference ΔTm = 6. As described above, the target temperature difference ΔTm of the reheat-side heat exchanger is set to be larger as the temperature of the sucked air is lower. In the example of FIG. 9B, the air diagram is divided into three regions, but the present invention is not limited to this and may be divided into any number.

  The control device opens the opening (opening) of the heat medium flow control device 25b so that the difference between the temperature detected by the first temperature sensor 31b and the temperature detected by the second temperature sensor 34b becomes the target temperature difference ΔTm. Area). That is, when the difference between the temperature of the heat medium before flowing into the reheat side heat exchanger and the temperature of the heat medium after flowing out of the reheat side heat exchanger is larger than the target temperature difference ΔTm, the heat exchange capacity Is increased, the opening degree of the heat medium flow control device 25b is increased. On the other hand, if the difference between the temperature of the heat medium before flowing into the reheat side heat exchanger and the temperature of the heat medium after flowing out of the reheat side heat exchanger is smaller than the target temperature difference ΔTm, the heat exchange capacity In order to decrease the opening degree of the heat medium flow control device 25b.

  In addition, when the temperature of the air sucked into the indoor unit 2a is larger than the target temperature Xm by a predetermined value or more, the circulation of the heat medium may be stopped to prevent an excessive temperature rise. For example, when the control device detects X−Xm ≧ 0.5, the heat medium flow control device 25b is fully closed.

  As described above, in the reheat dehumidifying operation mode, the temperature and humidity of the indoor air sucked into the indoor unit 2a that is the indoor air suction type can be controlled.

[Control of indoor unit 2b which is an outside air suction type]
Next, the control of the indoor unit 2b which is an outside air suction type will be described with reference to FIG.
FIG. 10 is an air line diagram illustrating the circulation amount control of the heat medium in the reheat dehumidifying operation mode according to the embodiment of the present invention. FIG. 10A is an air diagram illustrating the target temperature difference ΔTm of the use side heat exchanger 26c (hereinafter also referred to as a main side heat exchanger). FIG. 10B is an air diagram illustrating the target temperature difference ΔTm of the use side heat exchanger 26b (hereinafter also referred to as a reheat side heat exchanger).

[Main heat exchanger]
As shown in FIG. 10 (a), the air showing the correlation between the temperature and humidity of the air according to the difference between the temperature and humidity of the air blown out from the indoor unit 2b and the target temperature Xm and the target humidity Ym. Divide the diagram into multiple regions. And target temperature difference (DELTA) Tm (heat exchange capability) is preset for every some area | region. For example, when the detected value of the blown air temperature sensor 41 is X and the detected value of the blown air humidity sensor 42 is Y, the temperature ranges are X-Xm ≧ 1 ° C., 1> X-Xm ≧ −1 ° C., X− It is divided into three ranges of Xm <−1 ° C. Further, the humidity range is divided into three ranges: Y−Ym ≧ 5%, 5%> Y−Ym ≧ −5%, and Y−Ym <−5%. And it divides | segments into nine area | regions which combined each of the temperature range and the humidity range. In this example, the humidity is relative humidity detection.

  A target temperature difference ΔTm (heat exchange capability) (1) to (4) is set in advance in each of the nine regions. Here, for example, (1) is set to target temperature difference ΔTm = 2, (2) is set to target temperature difference ΔTm = 3, (3) is set to target temperature difference ΔTm = 5, and (4) is set to target temperature difference ΔTm = 7. Is done. Thus, the target temperature difference ΔTm of the main-side heat exchanger is set larger as the temperature of the blown air is higher and the humidity is higher. In the example of FIG. 10A, the air diagram is divided into nine regions, but the present invention is not limited to this and may be divided into any number.

  The control device opens the opening (opening) of the heat medium flow control device 25c so that the difference between the temperature detected by the first temperature sensor 31a and the temperature detected by the second temperature sensor 34c becomes the target temperature difference ΔTm. Area). That is, when the difference between the temperature of the heat medium before flowing into the main heat exchanger and the temperature of the heat medium after flowing out of the main heat exchanger is larger than the target temperature difference ΔTm, the heat exchanging capacity Is increased, the opening degree of the heat medium flow control device 25c is increased. On the other hand, if the difference between the temperature of the heat medium before flowing into the main heat exchanger and the temperature of the heat medium after flowing out of the main heat exchanger is smaller than the target temperature difference ΔTm, the heat exchanging capacity In order to reduce the opening degree of the heat medium flow control device 25c.

  In addition, when the temperature of the air blown out from the indoor unit 2a is smaller than the target temperature Xm by a predetermined value or more, circulation of the heat medium may be stopped to prevent an excessive temperature drop. For example, when the control device detects X−Xm <−5, the control unit 25c fully closes the heat medium flow control device 25c.

[Reheat-side heat exchanger]
As shown in FIG. 10B, the air diagram is divided into a plurality of regions according to the difference between the temperature of the air blown out from the indoor unit 2b and the target temperature Xm. And target temperature difference (DELTA) Tm (heat exchange capability) is preset for every some area | region. For example, when the detected value of the blown air temperature sensor 41 is X, the temperature ranges are 0.5> X−Xm ≧ −1, −1> X−Xm ≧ −2, and X−Xm <−2. Separate into two ranges.

  A target temperature difference ΔTm (heat exchange capability) (1) to (3) is set in advance in each of the three regions. Here, for example, (1) is set to the target temperature difference ΔTm = 2, (2) is set to the target temperature difference ΔTm = 4, and (3) is set to the target temperature difference ΔTm = 6. As described above, the target temperature difference ΔTm of the reheat-side heat exchanger is set to be larger as the temperature of the sucked air is lower. In addition, in the example of FIG.10 (b), although the air line figure was divided into three area | regions, this invention is not limited to this, You may divide into arbitrary numbers.

  The control device opens the opening (opening) of the heat medium flow control device 25d so that the difference between the temperature detected by the first temperature sensor 31b and the temperature detected by the second temperature sensor 34d becomes the target temperature difference ΔTm. Area). That is, when the difference between the temperature of the heat medium before flowing into the reheat side heat exchanger and the temperature of the heat medium after flowing out of the reheat side heat exchanger is larger than the target temperature difference ΔTm, the heat exchange capacity Is increased, the opening degree of the heat medium flow control device 25d is increased. On the other hand, if the difference between the temperature of the heat medium before flowing into the reheat side heat exchanger and the temperature of the heat medium after flowing out of the reheat side heat exchanger is smaller than the target temperature difference ΔTm, the heat exchange capacity In order to decrease the opening of the heat medium flow control device 25d.

  In addition, when the temperature of the air blown out from the indoor unit 2b is larger than the target temperature Xm by a predetermined value or more, the circulation of the heat medium may be stopped to prevent an excessive temperature rise. For example, when detecting that X−Xm ≧ 0.5, the control device fully closes the heat medium flow control device 25d.

  As described above, in the reheat dehumidifying operation mode, the temperature and humidity of the air blown out from the indoor unit 2b that is an outside air suction type can be controlled.

[Temperature control of heat medium]
Next, the temperature control of the heat medium in the reheat dehumidifying operation mode will be described.
FIG. 11 is a flowchart showing the switching operation to the heat medium temperature control of the air-conditioning apparatus according to the embodiment of the present invention. Hereinafter, a description will be given based on each step of FIG.
When the operation of the air conditioner 100 is started (step 1), the control device starts the switching operation to the heat medium temperature control and determines whether there is an indoor unit 2 that is executing the reheat dehumidifying operation mode (step 2). ). When there is an indoor unit 2 that is executing the reheat dehumidifying operation mode, the control device determines whether or not the indoor unit 2 that is executing the reheat dehumidifying operation mode is an outdoor air suction type indoor unit 2b ( Step 3).

  When the indoor unit 2 that is executing the reheat dehumidifying operation mode is the outdoor air suction type indoor unit 2b, the control device obtains the dew point temperature Zm based on the target temperature Xm and the target humidity Ym. And the target value (cooling target heat medium temperature) of the heat medium which flows through the main side heat exchanger of the indoor unit 2b is set to the dew point temperature Zm. Moreover, the target value (heating target heat medium temperature) of the heat medium flowing through the reheat side heat exchanger of the indoor unit 2b is set to a predetermined value (for example, 50 ° C.). Then, heat medium temperature control described later is executed (step 4).

  When the indoor unit 2 that is executing the reheat dehumidifying operation mode is the indoor air suction type indoor unit 2a, the control device sets the target value (cooling) of the temperature of the heat medium flowing through the main heat exchanger of the indoor unit 2a. The target heat medium temperature) is set to a predetermined value (for example, 5 ° C.). Moreover, the target value (heating target heat medium temperature) of the heat medium flowing through the reheat side heat exchanger of the indoor unit 2a is set to a predetermined value (for example, 50 ° C.). Then, heat medium temperature control described later is executed (step 5).

  When there is no indoor unit 2 that is executing the reheat dehumidifying operation mode, the control device does not execute the heat medium temperature control described later, and the above-described heating only operation mode, cooling only operation mode, cooling main operation mode, heating Control in the main operation mode is performed (step 6).

  The control device determines whether or not the operation of the air conditioner 100 has stopped (step 7). If the operation has not stopped, the control device returns to step 2 and ends the control if the operation has stopped. (Step 8).

FIG. 12 is a flowchart showing heat medium temperature control of the air-conditioning apparatus according to the embodiment of the present invention. Hereinafter, description will be given based on each step of FIG.
When the heat medium temperature control starts (step 11), the control device sets a target value (target condensation temperature) of the heat source side refrigerant temperature of the heat exchanger related to heat medium 15b acting as a condenser based on the heating target refrigerant temperature. Set. Further, based on the cooling target refrigerant temperature, a target value (target evaporation temperature) of the heat source side refrigerant of the heat exchanger related to heat medium 15a acting as an evaporator is set. Furthermore, a superheat target value (target SH) and a supercool target value (target SC) in the refrigerant circuit A are set. For example, the target condensation temperature is set to a temperature obtained by adding a predetermined value to the heating target refrigerant temperature (for example, target condensation temperature = heating target refrigerant temperature + 5 ° C.). The target evaporation temperature is a temperature obtained by subtracting a predetermined value from the cooling target refrigerant temperature, and exceeds a lower limit temperature (for example, −2 ° C.) (for example, target evaporation temperature = cooling target water temperature−5 ° C.> − 2 ° C.). Set to. The target SH and the target SC are set to predetermined values (for example, target SH = 2, target SC = 10) (step 2).

  The control device determines whether or not a predetermined time (for example, 20 minutes) has elapsed from the start of the heat medium temperature control (step 13). If the predetermined time has not elapsed, the control device returns to step 12 and the predetermined time has elapsed. If so, go to Step 14.

  The control device determines whether the difference between the cooling target refrigerant temperature and the temperature of the heat medium flowing through the main heat exchanger (detected values of the second temperature sensors 34a and 34c) is greater than a predetermined temperature (eg, 3 ° C.). It is determined whether or not (step 14).

When the determination in step 14 is satisfied, the control device is a temperature obtained by subtracting the second predetermined value (for example, 7 ° C.) from the cooling target refrigerant temperature, and exceeds the lower limit temperature (for example, −2 ° C.). The temperature (for example, target evaporation temperature = cooling target water temperature−7 ° C.> − 2 ° C.) is set (step 15).
When the determination in step 14 is not satisfied, the control device is a temperature obtained by subtracting the third predetermined value (for example, 5 ° C.) from the cooling target refrigerant temperature, and exceeds the lower limit temperature (for example, −2 ° C.). The temperature (for example, target evaporation temperature = cooling target water temperature−5 ° C.> − 2 ° C.) is set (step 16). Note that the third predetermined value is smaller than the second predetermined value. The control device controls the compressor 10, the expansion device 16a, and the like in the refrigerant circuit A based on the target evaporation temperature and the target condensation temperature.

  The control device determines whether or not the heat medium temperature control has ended (step 17). If it has not ended, the control device returns to step 14, and if it has ended, this control ends (step 18).

As described above, since the temperature of the heat medium in the heat medium circuit B serving as the secondary loop fluctuates due to the temperature fluctuation of the heat source side refrigerant in the refrigerant circuit A serving as the primary loop, the temperature fluctuation of the heat medium is reduced, Variations in the temperature and humidity of the indoor air can be suppressed. Therefore, the indoor temperature and humidity become stable, and the indoor comfort can be improved.
In addition, since the target evaporation temperature and the target condensation temperature in the refrigerant circuit A are set by the cooling target heat medium temperature and the heating target heat medium temperature of the heat medium in the heat medium circuit B, the refrigerant circuit A serving as a primary loop. As a result, the temperature tracking of the heat source side refrigerant is also delayed. Therefore, the indoor temperature and humidity become stable, and the indoor comfort can be improved.

  In the above description, the case of performing the circulation amount control of the heat medium and the temperature control of the heat medium has been described, but the present invention is not limited to this. Only one of the circulation control of the heat medium and the temperature control of the heat medium may be performed. Further, at least one of the heat medium circulation amount control and the temperature control may be performed on at least one of the indoor unit 2a and the indoor unit 2b.

[Modification]
FIG. 13: is a flowchart which shows the modification of the heat medium temperature control of the air conditioning apparatus which concerns on embodiment of this invention. Hereinafter, based on each step of FIG. 13, it demonstrates centering on difference with FIG.

Steps 21 to 24 are the same as steps 11 to 14 in FIG.
If the determination in step 24 is satisfied, the control device sets the target SH to a second predetermined value (for example, 2) (step 25).
If the determination in step 24 is not satisfied, the control device sets the target SH to a third predetermined value (for example, 5) (step 25). Note that the third predetermined value is smaller than the second predetermined value. The control device controls the compressor 10, the expansion device 16a and the like in the refrigerant circuit A based on the target SH and the target SC.
Steps 27 and 28 are the same as steps 17 and 18 in FIG.

  Thus, the temperature of the heat source side refrigerant in the refrigerant circuit A may be controlled to the target SH and the target SC. In this case, the same effect can be obtained.

  In the present embodiment, the indoor unit 2 is only the type that performs the reheat dehumidifying operation, but an indoor unit that performs only normal cooling and heating may be provided.

  1 outdoor unit, 2a indoor unit, 2b indoor unit, 3 heat medium converter, 4 refrigerant pipe, 4a first connection pipe, 4b second connection pipe, 5 pipe, 6 outdoor space, 7 indoor space, 8 space, 9 building DESCRIPTION OF SYMBOLS 10 Compressor, 11 1st refrigerant | coolant flow path switching device, 12 Heat source side heat exchanger, 13a-13d Check valve, 15a, 15b Heat exchanger between heat media, 16a, 16b Throttle device, 17a, 17b Opening and closing device, 18a, 18b Second refrigerant flow switching device, 19 Accumulator, 21a, 21b Pump, 22a-22d First heat medium flow switching device, 23a-23d Second heat medium flow switching device, 25a-25d Heat medium flow rate Adjustment device, 26a-26d use side heat exchanger, 31a, 31b first temperature sensor, 34a-34d second temperature sensor, 35a-35d third temperature sensor, 36 1 pressure sensor, 37 2nd pressure sensor, 38 3rd pressure sensor, 39 suction air temperature sensor, 40 suction air humidity sensor, 41 blowing air temperature sensor, 42 blowing air humidity sensor, 50 4th temperature sensor, 52 arithmetic unit, 57 arithmetic unit, 100 air conditioner, A refrigerant circulation circuit, B heat medium circulation circuit.

An air conditioner according to the present invention includes a compressor, a heat source side heat exchanger, a plurality of expansion devices, a refrigerant side flow path of a plurality of heat exchangers between heat media, and a plurality of refrigerant flow switching devices that switch a circulation path. A refrigerant circulation circuit that circulates the heat source side refrigerant by connecting refrigerant pipes, a pump, a plurality of use side heat exchangers, a heat medium flow switching device, and a heat medium side flow path of the inter-heat medium heat exchanger A heat medium circulation circuit that circulates the heat medium by connecting the heat medium pipes, and an indoor unit in which two or more use side heat exchangers are housed, and the plurality of heat medium heat exchangers Cooling the heat medium by flowing a low-temperature and low-pressure heat-source-side refrigerant to a part thereof, supplying the cooled heat medium to a part of the use-side heat exchanger housed in the indoor unit, and Heating the heat medium by flowing a high-temperature and high-pressure heat source side refrigerant to the other part of the inter-medium heat exchanger, Some internal mechanism of another stowed the use side heat exchanger, and supplies the heat medium heated by the air conditioning apparatus performing the operation mode humidity Rehito removal, the air sucked into the indoor unit Based on the temperature difference between the temperature and the target temperature, and the humidity difference between the humidity of the air sucked into the indoor unit and the target humidity, the heat exchange capacity of the use side heat exchanger that supplies the cooled heat medium is set. And based on the temperature difference between the temperature of the air sucked into the indoor unit and the target temperature, set the heat exchange capacity of the use side heat exchanger that supplies the heated heat medium, and based on the heat exchange capacity, An arithmetic device that controls at least one of a circulation amount of the heat medium circulating through the use-side heat exchanger and a temperature of the heat medium; and the arithmetic device obtains a dew point temperature based on the target temperature and the target humidity. Cooled The target value of the temperature of the serial heating medium, and setting the dew point temperature.

Claims (8)

A compressor, a heat source side heat exchanger, a plurality of expansion devices, a refrigerant side flow path of a plurality of heat exchangers between heat media, and a plurality of refrigerant flow switching devices for switching circulation paths are connected by a refrigerant pipe to the heat source side A refrigerant circulation circuit for circulating the refrigerant;
A heat medium circulation circuit that circulates the heat medium by connecting the heat medium side flow path of the heat exchanger between the heat medium with a heat medium pipe; and a pump, a plurality of use side heat exchangers, a heat medium flow switching device, and ,
An indoor unit in which two or more use side heat exchangers are accommodated;
With
The low-temperature and low-pressure heat source side refrigerant is allowed to flow through a part of the plurality of heat exchangers between the heat mediums to cool the heat medium, and the part of the use side heat exchangers accommodated in the indoor unit is cooled. Supply heat medium,
A high-temperature and high-pressure heat source side refrigerant is allowed to flow through another part of the plurality of heat exchangers between the heat mediums to heat the heat medium, and to other parts of the use side heat exchangers housed in the indoor unit A reheat dehumidifying operation mode for supplying the heated heat medium is executed. The use side heat that supplies the cooled heat medium based on the temperature difference between the temperature of the air sucked into the indoor unit and the target temperature, and the humidity difference between the humidity of the air sucked into the indoor unit and the target humidity Set the heat exchange capacity of the exchanger,
Based on the temperature difference between the temperature of the air sucked into the indoor unit and the target temperature, the heat exchange capacity of the user side heat exchanger that supplies the heated heat medium is set,
2. The air conditioner according to claim 1, wherein at least one of a circulation amount of the heat medium circulating through the use side heat exchanger and a temperature of the heat medium is controlled based on the heat exchange capability. The use of supplying the cooled heat medium based on the temperature difference between the temperature of the air blown out from the indoor unit and a target temperature, and the humidity difference between the humidity of the air blown out of the indoor unit and the target humidity Set the heat exchange capacity of the side heat exchanger,
Based on the temperature difference between the temperature of the air blown out from the indoor unit and the target temperature, the heat exchange capacity of the use side heat exchanger that supplies the heated heat medium is set,
2. The air conditioner according to claim 1, wherein at least one of a circulation amount of the heat medium circulating through the use side heat exchanger and a temperature of the heat medium is controlled based on the heat exchange capability. The higher the temperature of the air and the higher the humidity of the air, the larger the heat exchange capacity of the user side heat exchanger that supplies the cooled heat medium,
4. The air conditioner according to claim 2, wherein a heat exchange capacity of the use side heat exchanger that supplies the heated heat medium is set to be larger as the temperature of the air is lower. 5. An air diagram showing a correlation between air temperature and humidity is divided into a plurality of regions according to the difference between the target temperature and the target humidity, and a heat exchange capacity is preset for each of the plurality of regions,
5. The heat exchanger capacity in the region corresponding to the temperature and humidity of the air is set in the use side heat exchanger that supplies the heated heat medium. 6. The air conditioning apparatus described. A dew point temperature is obtained based on the target temperature and the target humidity,
The air conditioning apparatus according to any one of claims 2 to 5, wherein a target value of the temperature of the cooled heat medium is set to the dew point temperature. The air conditioning apparatus according to any one of claims 2 to 6, wherein the temperature of the cooled heat medium is adjusted by controlling an evaporation temperature of a heat source side refrigerant circulating in the refrigerant circulation circuit. . The air conditioning apparatus according to any one of claims 2 to 7, wherein the temperature of the heated heat medium is adjusted by controlling a condensation temperature of a heat source side refrigerant circulating in the refrigerant circulation circuit. .

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