JPWO2012101673A1 - Air conditioner - Google Patents

Abstract

In the air conditioner 100 having the compressor 10, the heat source side heat exchanger 12, the expansion device 16, and the load side heat exchanger 15, and having these components connected by refrigerant piping, the refrigeration cycle is performed. Blocking devices 37 and 38 that pass or block circulating refrigerant, a detection unit that detects refrigerant leakage with a resistance value that changes according to the concentration of a plurality of leaked refrigerants, and leakage based on the resistance value of the detection unit Based on the concentration calculation unit 41 that calculates the concentration of the refrigerant, the concentration detection unit 39 that outputs the calculation result of the concentration calculation unit 41 for use in the control of the blocking devices 37 and 38, and the output of the concentration detection unit 39, And a shutoff control device 40 for controlling the shutoff devices 37 and 38.

Description

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

Some air conditioners include a heat source unit (outdoor unit) arranged outside a building and an indoor unit arranged inside a building, such as a building multi-air conditioner. The refrigerant circulating in the refrigerant circuit of such an air conditioner radiates heat (heat absorption) to the air supplied to the heat exchanger of the indoor unit, and heats or cools the air. The heated or cooled air is sent into the air-conditioning target space for heating or cooling.
In such an air conditioner, a building normally has a plurality of indoor spaces, and accordingly, the indoor unit also includes a plurality of indoor units. Moreover, when the scale of the building is large, the refrigerant pipe connecting the outdoor unit and the indoor unit may be 100 m. When the length of the pipe connecting the outdoor unit and the indoor unit is long, the amount of refrigerant charged in the refrigerant circuit increases accordingly.

And if the refrigerant | coolant with which the refrigerant circuit was filled causes a refrigerant | coolant leak for some reason, there exists a possibility that the leaked refrigerant | coolant may flow out into indoor space. In that case, if the refrigerant is flammable, there is a risk of fire. Moreover, when a refrigerant | coolant has toxicity, it is assumed that it has a bad influence on a human body.
Thus, a conventional air conditioner has been proposed in which the operation of the compressor is stopped when the refrigerant leaks (see, for example, Patent Document 1). The technique described in Patent Document 1 uses carbon dioxide as a refrigerant and stops the compressor when a carbon dioxide refrigerant leaks.

JP 2000-320936 A (see, for example, paragraphs [0024] to [0033] and FIGS. 2 to 4 of the specification)

  The technique described in Patent Document 1 uses carbon dioxide as a refrigerant and stops the system when a carbon dioxide refrigerant leak occurs like a conventional refrigerant leak. No measures are taken against leaks. In other words, when carbon dioxide is used as a refrigerant, it is necessary to take some measures to reduce refrigerant leakage on the premise that the human body is not adversely affected. Similarly, since the flammable refrigerant has flammability, it is necessary to provide some kind of safety device as in the case of carbon dioxide in order to ensure the safety of the system.

  In recent years, from the viewpoint of global warming, there has been a movement to limit the use of HFC refrigerants with high global warming potential (for example, R410A, R404A, R407C, R134a, etc.), and refrigerants with low global warming potential (for example, An air conditioner using HFO1234yf, R32, HC, carbon dioxide and the like has been proposed. Even when flammable refrigerants (HFO1234yf, R32, and HC) or carbon dioxide are used as refrigerants in building multi-air conditioners, a large amount of refrigerant is required, so measures should be taken when the refrigerant leaks into the indoor space. I have to leave.

  The air conditioner according to the present invention is made in response to the above-described problems, and an object thereof is to provide an effective measure for refrigerant leakage in the refrigeration cycle apparatus.

  An air conditioner according to the present invention includes a compressor, a heat source side heat exchanger, a throttling device, and a load side heat exchanger, which are connected to each other by a refrigerant pipe and have a refrigeration cycle. , A shut-off device that passes or blocks the refrigerant circulating in the refrigeration cycle, a detection unit that detects a refrigerant leak with a resistance value that changes according to the concentration of the plurality of leaked refrigerants, and a leak based on the resistance value of the detection unit A concentration calculation unit that calculates the concentration of the refrigerant, a concentration detection unit that outputs the calculation result of the concentration calculation unit for use in control of the cutoff device, and controls the cutoff device based on the output of the concentration detection unit And a shut-off control device.

  Since the air conditioner according to the present invention has the above configuration, the safety of the air conditioner can be improved.

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. The relationship between the resistance value of the detection member of a density | concentration detection part and a refrigerant | coolant density | concentration is shown according to the kind of refrigerant | coolant. The another refrigerant circuit structural example of the air conditioning apparatus which concerns on embodiment of this invention is shown.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment FIG. 1 is a schematic diagram illustrating an installation example of an air-conditioning apparatus 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-conditioning apparatus 100 according to the present embodiment detects the leakage when the refrigerant leaks, and flows into the outdoor unit 1 and the refrigerant flow flowing out of the outdoor unit 1 (heat source unit). It has a function of blocking the flow of the refrigerant. Thus, the amount of refrigerant leaking from the air conditioning apparatus 100 is reduced, and user safety is achieved.

  In addition, the air conditioning apparatus 100 according to the present embodiment includes a refrigerant circulation circuit A (see FIG. 2) that is a refrigeration cycle for circulating the heat source side refrigerant and a heat medium circulation circuit B (see FIG. 2) that circulates the heat medium. Each indoor unit can select a cooling operation mode or a heating operation mode as an operation mode.

  The air conditioning apparatus 100 employs a method (indirect method) that indirectly uses a refrigerant (heat source side refrigerant). That is, the air conditioning apparatus 100 according to the present embodiment transmits the cold or warm heat stored in the heat source side refrigerant to a refrigerant (hereinafter referred to as a heat medium) different from the heat source side refrigerant, and the cold heat stored in the heat medium. Alternatively, the air-conditioning space is cooled or heated with heat.

  In FIG. 1, an air conditioner 100 flows through the indoor unit 2 by using one outdoor unit 1 that is a heat source unit, a plurality of indoor units 2, and the cold or hot heat of the heat-source-side refrigerant that flows through the outdoor unit 1. It has a heat medium converter 3 for transmitting to the heat medium. The heat medium relay unit 3 exchanges heat between the heat source side refrigerant and the heat medium. The outdoor unit 1 and the heat medium relay unit 3 are configured by being connected by a refrigerant pipe 4 that conducts the heat source side refrigerant. The heat medium relay unit 3 and the indoor unit 2 are connected by a heat medium pipe 5 that conducts the heat medium. The cold or warm heat generated by the outdoor unit 1 is transmitted to the heat medium of the heat medium converter 3 and delivered to the indoor unit 2. Moreover, although demonstrated in FIG. 2, the air conditioning apparatus 100 which concerns on this Embodiment is provided with the 1st cutoff device 37 and the 2nd cutoff device 38 (refer FIG. 2) inside the outdoor unit 1. FIG.

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

  As shown in FIG. 1, in the air conditioning apparatus 100 according to the embodiment, an outdoor unit 1 and a heat medium converter 3 are connected via a refrigerant pipe 4, and the heat medium converter 3 and each indoor unit 2 are connected to each other. Are connected via the heat medium pipe 5. Thus, in the air conditioning apparatus 100, each unit (the outdoor unit 1, the indoor unit 2, and the heat medium converter 3) is connected using the refrigerant pipe 4 and the heat medium pipe 5, and the construction is easy. ing.

  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, An example of a state where it is installed in the space 8) is shown. The heat medium relay 3 can also be installed in a common space where there is an elevator or the like. Moreover, in FIG. 1, although the case where the indoor unit 2 is a ceiling cassette type | mold is shown as an example, it is not limited to this, It is directly or directly in the indoor space 7, such as a ceiling embedded type and a ceiling suspended type. There is no particular limitation as long as heating air or cooling air can be supplied to the indoor space 7 by a duct or the like.

  Moreover, in FIG. 1, although the case where the outdoor unit 1 is installed in the outdoor space 6 is shown as an example, it is not limited to this. For example, the outdoor unit 1 may be installed in an enclosed space such as a machine room with a ventilation opening. If the exhaust heat can be exhausted outside the building 9 by an exhaust duct, the outdoor unit 1 may be installed inside the building 9. It may be installed, or may be installed inside the building 9 when the water-cooled outdoor unit 1 is used.

  The heat medium relay unit 3 may be installed in a position near the outdoor unit 1 and away from the indoor unit 2. However, if the distance from the heat medium converter 3 to the indoor unit 2 is increased, the power (energy) necessary for transporting the heat medium is considerably increased, so that the energy saving effect is reduced. 3 should be installed. Furthermore, the number of connected units of the outdoor unit 1, the indoor unit 2, and the heat medium relay unit 3 is not particularly limited, and the number may be determined according to the building 9.

  FIG. 2 is a refrigerant circuit configuration example of the air-conditioning apparatus 100 according to Embodiment 1 of the present invention. Based on FIG. 2, the refrigerant circuit structure of the air conditioning apparatus 100 will be described. As shown in FIG. 2, the outdoor unit 1, and 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 are connected to the refrigerant pipe 4 (high-pressure side refrigerant pipe 4 a ( 2) and the low-pressure side refrigerant pipe 4b (2)). Further, the heat exchanger related to heat medium 15 a and the heat exchanger 15 b between heat medium and the indoor units 2 a to 2 d (also simply referred to as the indoor unit 2) are connected via the heat medium pipe 5. .

[Configuration of outdoor unit 1]
The outdoor unit 1 includes a compressor 10, a first refrigerant flow switching device 11, a heat source side heat exchanger 12, an accumulator 19, a first shut-off device 37, and a second shut-off device 38. They are connected by piping.
The compressor 10 sucks in the refrigerant, compresses the refrigerant to a high temperature and high pressure state, and conveys the refrigerant to the refrigerant circuit A. The compressor 10 has a discharge side connected to the first refrigerant flow switching device 11 and a suction side connected to an accumulator 19. The compressor 10 may be composed of, for example, an inverter compressor capable of capacity control.

  The first refrigerant flow switching device 11 includes a discharge side of the compressor 10, a check valve 13b, a heat source side heat exchanger 12, and an accumulator in the heating only operation mode and the heating main operation mode of the mixed heating and cooling operation mode. 19 suction sides are connected. Further, the first refrigerant flow switching device 11 is provided with the discharge side of the compressor 10, the heat source side heat exchanger 12, the check valve 13d, and the accumulator in the cooling operation mode and the cooling main operation mode of the mixed cooling and heating operation mode. The suction side of the lator 19 is connected. The first refrigerant flow switching device 11 may be configured with, for example, a four-way valve.

  The heat source side heat exchanger 12 functions as an evaporator during heating operation, functions as a radiator (gas cooler) during cooling operation, and exchanges heat between air and refrigerant supplied from a blower such as a fan (not shown). Is to do. One side of the heat source side heat exchanger 12 is connected to the check valve 13 c and the other side is connected to the suction side of the accumulator 19 in the heating operation mode. In the cooling operation mode, one of the heat source side heat exchangers 12 is connected to the discharge side of the compressor 10 and the other is connected to the check valve 13a. The heat source side heat exchanger 12 may be configured by, for example, a plate fin and tube heat exchanger that can exchange heat between the refrigerant flowing through the refrigerant pipe and the air passing through the fins.

  The accumulator 19 stores surplus refrigerant due to a difference between the heating operation mode and the cooling operation mode, and surplus refrigerant with respect to a transient operation change (for example, a change in the number of operating indoor units 2). The accumulator 19 has a suction side connected to the heat source side heat exchanger 12 and a discharge side connected to the suction side of the compressor 10 in the heating operation mode. The accumulator 19 has a suction side connected to the check valve 13d and a discharge side connected to the suction side of the compressor 10 in the cooling operation mode.

Further, the outdoor unit 1 is provided with a first connection pipe 42a, a second connection pipe 42b, a check valve 13a, a check valve 13b, a check valve 13c, and a check valve 13d. By providing the first connection pipe 42a, the second connection pipe 42b, the check valve 13a, the check valve 13b, the check valve 13c, and the check valve 13d, the outdoor unit regardless of the heating operation mode or the cooling operation mode. The flow of the heat source side refrigerant flowing from 1 to the heat medium relay unit 3 can be in a certain direction.
That is, the refrigerant discharged from the compressor 10 flows into the high-pressure side refrigerant pipe 4a (2). The refrigerant that has flowed into the high-pressure side refrigerant pipe 4 a (2) flows into the heat medium relay unit 3. The refrigerant that has flowed through the heat medium relay unit 3 flows into the outdoor unit 1 from the low-pressure side refrigerant pipe 4b (2).

The high-pressure side refrigerant pipe 4a (1) is a pipe in the outdoor unit 1 and refers to a pipe downstream from the point P2 illustrated in FIG. The high-pressure side refrigerant pipe 4 a (2) is a pipe connected to the high-pressure side refrigerant pipe 4 a (1) in the refrigerant pipe 4.
The low-pressure side refrigerant pipe 4b (1) is a pipe in the outdoor unit 1 and refers to a pipe upstream from the point P3 illustrated in FIG. The low pressure side refrigerant pipe 4 b (2) is a pipe connected to the low pressure side refrigerant pipe 4 b (1) in the refrigerant pipe 4.

The first shut-off device 37 and the second shut-off device 38 flow the refrigerant (open state) or block the refrigerant flow (closed state) based on the operation of the shut-off control device 40 described later.
The first blocking device 37 and the second blocking device 38 are preferably provided in the outdoor unit 1 or in the vicinity of the outdoor unit 1. That is, the first shut-off device 37 may be connected to the high-pressure side refrigerant pipe 4a (1), and the second shut-off device 38 may be connected to the low-pressure side refrigerant pipe 4b (1). Moreover, the 1st cutoff device 37 may be connected to the high voltage | pressure side refrigerant | coolant piping 4a (2), and the 2nd cutoff device 38 may be connected to the low voltage | pressure side refrigerant | coolant piping 4b (2).
The first shut-off device 37 and the second shut-off device 38 may be configured by, for example, a valve body, a sealing material that seals the valve body, and a two-way valve that has a coil that opens and closes the valve body with electromagnetic force. In the following description, it is assumed that the first shut-off device 37 and the second shut-off device 38 are two-way valves having a valve body, a sealing material that seals the valve body, and a coil that opens and closes the valve body with electromagnetic force. explain.

[Concentration detection mechanism of outdoor unit 1]
The air conditioning apparatus 100 includes a concentration detection unit 39 having a detection member (not shown) whose resistance value changes according to the refrigerant concentration, and a concentration calculation unit that calculates the refrigerant concentration based on the resistance value of the detection member. 41 and a shut-off control device 40 that controls opening and closing of the first shut-off device 37 and the second shut-off device 38 based on the calculated refrigerant concentration.
Further, the concentration detection unit 39 outputs a predetermined signal to the cutoff control device 40 based on the calculation result of the refrigerant concentration of the concentration calculation unit 41.
Specifically, when the calculation result of the refrigerant concentration of the concentration calculation unit 41 is less than a predetermined concentration value, the predetermined signal is not output to the cutoff control device 40.
On the other hand, when the calculation result of the refrigerant concentration of the concentration calculation unit 41 is equal to or greater than a predetermined concentration value, a predetermined signal is output to the cutoff control device 40.

The concentration detection unit 39 is electrically connected to the concentration calculation unit 41 and the cutoff control device 40. The output to the cutoff control device 40 is not particularly limited, but may be, for example, a DC voltage (5V, 12V, 24V, etc.), an AC voltage, a current, or other output. In addition, in the air conditioning apparatus 100 which concerns on this Embodiment, the output to the interruption | blocking control apparatus 40 is demonstrated as what is DC5V.
The predetermined concentration corresponds to the refrigerant leakage limit concentration or explosion limit lower limit value employed in the air conditioner 100. For example, the predetermined concentration when carbon dioxide is used as the refrigerant is preferably set to about 1/10 of the leakage limit concentration. Moreover, it is preferable that the predetermined concentration when the flammable refrigerant (HFO1234yf, R32, HC) is used is set to about 1/10 of the lower limit of explosion limit.

  The position where the detection member of the concentration detection unit 39 is provided is not particularly limited, but for example, in the outdoor unit 1 illustrated in FIG. 1, in the vicinity of the outdoor unit 1, in the heat medium converter 3, and in the outdoor space. 6. It is good to install in indoor space 7, space 8, etc.

FIG. 7 shows the relationship between the resistance value of the detection member of the concentration detection unit 39 and the refrigerant concentration for each type of refrigerant. This detection member is preferably composed of, for example, a tin oxide (SnO ² ) semiconductor. As shown in FIG. 7, it can be seen that the resistance value of the tin oxide (SnO ² ) semiconductor gradually decreases as the gas concentration of the refrigerant increases. That is, the refrigerant concentration can be uniquely determined by calculating the resistance value of the detection member.
Incidentally, in the case where the detection member with tin oxide (SnO ²⁾ semiconductor, major refrigerant (R410A, R407C, R32, HFO1234yf ) relationship of the resistance value and the refrigerant concentration is, it can be seen that substantially the same tendency. That is, the refrigerant concentration can be detected with the same calibration curve for the main refrigerant. In other words, the concentration of a plurality of refrigerants can be detected with one detection member, and the concentration detection unit 39 can be standardized.
In addition, when the concentration detection unit 39 can be standardized in this way, it is not necessary to provide a plurality of detection members for each type of refrigerant, so that the cost of the air conditioner 100 can be reduced.

The chemical formula of HFO1234yf is CF ₃ —CF═CH ₂ . The chemical formula of HFO1234ze, which is an isomer of HFO1234yf, is CHF ₂ —CF═CHF, and its chemical characteristics are very similar to those of HFO1234yf. Therefore, the electrical resistance characteristics of the detection section of the concentration detection section 39 of the present invention are almost the same. . Therefore, it can be detected by the concentration detector 39 according to the present embodiment.
Moreover, when R32 and HFO1234yf are mixed, it becomes a non-azeotropic refrigerant mixture. When such a refrigerant leaks, the amount of leakage of R32, which is a low boiling point component, increases. That is, R32 reaches the limit concentration sooner than HFO1234yf. Therefore, the refrigerant leak can be detected on the safe side by detecting the refrigerant leak by measuring the leak of R32.
Even when other mixed refrigerants are used, if any one component of R410A, R407C, R32, HFO1234yf, and HFO1234ze is included, the electric resistance of the detection member changes. It can be detected. That is, by using the concentration detection unit 39 according to the present embodiment, it is possible to detect refrigerant leakage of the refrigerant mixture including HFC, HFO, HFC, and HFO.

  On the other hand, when the detection accuracy of the concentration detector 39 is further improved, the calibration curve of FIG. 7 can be created by creating a calibration curve for each refrigerant. In other words, each calibration curve corresponding to the type of refrigerant may be used without using the same calibration curve.

The concentration calculation unit 41 calculates (calculates) the refrigerant concentration based on the resistance value of the detection member of the concentration detection unit 39. The concentration calculation unit 41 is electrically connected to the concentration detection unit 39.
As shown in FIG. 7, the concentration calculation unit 41 stores the relationship between the refrigerant concentration and the resistance value of the detection member. Thereby, the density | concentration of the refrigerant | coolant employ | adopted as the air conditioning apparatus 100 can be calculated based on the resistance value of the detection member of the density | concentration detection part 39. FIG.
The position where the concentration calculation unit 41 is provided is not particularly limited, but may be installed, for example, in the outdoor unit 1 or in the vicinity of the outdoor unit 1. Hereinafter, the air conditioning apparatus 100 will be described with reference to FIG. 2 again.

The shutoff control device 40 controls the opening and closing of the first shutoff device 37 and the second shutoff device 38 based on the output (predetermined signal) of the concentration detector 39.
When the refrigerant concentration is equal to or higher than the predetermined concentration value, a predetermined signal is output from the concentration detection unit 39 to the cutoff control device 40. As a result, the electrical connection between the voltage source (not shown) and the first cutoff device 37 and the second cutoff device 38 is cut off. That is, no voltage is supplied from the voltage source to the first cutoff device 37 and the second cutoff device 38 (power is not supplied). Then, since the coils of the first shut-off device 37 and the second shut-off device 38 are not excited, the valve body is closed. That is, both the 1st cutoff device 37 and the 2nd cutoff device 38 will be in a closed state.

On the other hand, when the refrigerant concentration is less than the predetermined concentration value, no voltage is output from the concentration detection unit 39 to the cutoff control device 40. Thereby, a voltage source (illustration omitted) and the 1st cutoff device 37 and the 2nd cutoff device 38 are electrically connected. That is, a voltage is supplied (powered) from the voltage source to the first cutoff device 37 and the second cutoff device 38. Then, since the coils of the first shut-off device 37 and the second shut-off device 38 are excited, the valve body is opened. That is, both the 1st cutoff device 37 and the 2nd cutoff device 38 will be in an open state.
The position at which the shutoff control device 40 is provided is not particularly limited, but may be installed in, for example, the outdoor unit 1 or in the vicinity of the outdoor unit 1.

The first shut-off device 37 and the second shut-off device 38 are two-way valves having a valve body, a sealing material for sealing the valve body, and a coil for opening and closing the valve body by electromagnetic force as described above.
Each coil of the first shut-off device 37 and the second shut-off device 38 is connected to a voltage source via the shut-off control device 40. When the air-conditioning apparatus 100 is in normal operation, the shut-off control device 40 is in a state (energized state) in which the voltage source and the first shut-off device 37 and the second shut-off device 38 are electrically connected. Thereby, each coil of the 1st cutoff device 37 and the 2nd cutoff device 38 is supplied with a voltage from a voltage source, and becomes an electromagnet. And each valve body is attracted | sucked by electromagnetic force, and the 1st cutoff device 37 and the 2nd cutoff device 38 will be in an open state.

  On the other hand, when it is detected that the refrigerant of the air conditioner 100 has leaked, the shutoff control device 40 electrically shuts off the voltage source and the first shutoff device 37 and the second shutoff device 38 (non-energized state). As a result, the coils of the first cutoff device 37 and the second cutoff device 38 are not supplied with voltage from the voltage source. Then, the respective valve bodies are not attracted to the coil, and the first cutoff device 37 and the second cutoff device 38 are closed.

  When a mechanical electromagnet relay is used to switch the electrical connection between the voltage source and the first shut-off device 37 and the second shut-off device 38, a combustible refrigerant (HFO1234yf, R32, HC) is adopted as the refrigerant. In such a case, sparks may be generated and the refrigerant may be ignited. Therefore, when a flammable refrigerant is employed, an SRR (solid state relay) that is a non-contact relay using a semiconductor element may be employed for the shutoff control device 40. Thereby, since there is no mechanical operation | movement, possibility that a spark will generate | occur | produce can be reduced. Thereby, even if a combustible refrigerant | coolant leaks to the outdoor unit 1, the electrical connection of a voltage source and the 1st cutoff device 37 and the 2nd cutoff device 38 can be switched safely.

The coils for opening and closing the valve bodies of the first shut-off device 37 and the second shut-off device 38 may be excited with direct current. This is because the life of the coil can be extended by exciting with direct current. Therefore, it demonstrates as what supplies a DC voltage to the 1st cutoff device 37 and the 2nd cutoff device 38 as an operating voltage. The operation voltage is described as being DC 12V, but may be DC 24V or the like and is not limited.
The shutoff control device 40 also includes a converter that can convert a commercial power supply (AC, AC 200 V in the present embodiment) into a predetermined DC voltage (DC 12 V in the present embodiment). The voltage source described above corresponds to a commercial power source and a converter.

Since the 1st shut-off device 37 and the 2nd shut-off device 38 are installed in the main pipe (refrigerant piping 4) of a refrigerant circuit, it is necessary to enlarge a diameter. That is, it is necessary to increase the flow coefficient Cv value. Therefore, the first shut-off device 37 and the second shut-off device 38 may be pilot-type valves instead of direct acting types.
The Cv value of the first shut-off device 37 through which the high-pressure refrigerant passes is preferably 1 or more, for example, and the Cv value of the second shut-off device 38 through which the low-pressure refrigerant passes is, for example, 5 or more.
By using the Cv value as described above, even if the first shut-off device 37 and the second shut-off device 38 are provided in the refrigerant circuit, the pressure loss can be reduced, so that the performance degradation can be reduced. That is, the amount of refrigerant circulating in the refrigerant circuit A during normal operation decreases.

Moreover, the sealing material for sealing the valve body is preferably composed of rubber or PTFE (polytetrafluoroethylene). As a result, the valve body and the sealing material can be easily adapted (adhered to each other) immediately when driven in an emergency. That is, the leakage of the refrigerant when the first blocking device 37 and the second blocking device 38 are closed is reduced.
In addition, the 1st cutoff device 37 and the 2nd cutoff device 38 do not open and close frequently like a normal valve. Therefore, a metal seal excellent in durability may not be used as the sealing material.

Further, the first shut-off device 37 and the second shut-off device 38 are preferably configured such that the refrigerant leakage amount in the closed state is, for example, 1.0 × 10 ⁻⁶ [m ³ / s] or less. The reason for this will be described below.
If a large amount of refrigerant leaks into the space, there is a danger of combustion, lack of oxygen, etc., and a limit concentration that is the maximum concentration of the amount of refrigerant that can be safely used is defined for each type of refrigerant. Limit concentration, for example in the ^{R410A 0.44 [m 3 / kg]} , the ^{R32 0.061 [m 3 / kg]} , the ^{HFO1234yf 0.0578 [m 3 / kg]} , propane is 0.008 [m ³ / kg].

  Consider that when the refrigerant leaks into the room, the first shut-off device 37 and the second shut-off device 38 installed in the refrigerant pipe are closed to prevent the refrigerant from leaking. At this time, the prevention means for preventing the leakage of the refrigerant after the refrigerant reaches the limit concentration is not in time, so when the refrigerant concentration in the room reaches 95% of the limit concentration, the first shut-off device 37 and the first 2 Assume that the shut-off device 38 is closed. That is, after the first shut-off device 37 and the second shut-off device 38 are closed, the amount that the refrigerant may further leak before reaching the limit concentration is 5%.

Here, when the installation location of the building multi-air conditioner is assumed to be the smallest room or a single room of a hotel, the volume of this room is 25 m ^3, and the first shut-off device 37 and the second shut-off device 38 are It is assumed that the differential pressure before and after operation is 1.0 MPa, and the substantial space volume in the room excluding the unit bath and other objects is 0.5 × 25 = 12.5 m ³ . In this case, after the first blocking device 37 and the second shut-off device 38 closes, a good amount even leaks refrigerant becomes 12.5m ³ × 0.05 = 0.625m ^3. Within 24 hours after the first shut-off device 37 and the second shut-off device 38 are operated because it is expected that the space is closed with the window closed, without being aware of refrigerant leakage such as when sleeping. When the amount of leakage that does not reach the limit concentration is obtained, it is 0.625 / (24 × 60 × 60) = 7.2 × 10 ⁻⁶ [m ³ / s], and the first shut-off device 37 and the second shut-off device 38 are obtained. If the amount of leakage after closing is less than this value, it is safe.

In addition, it is unclear where the refrigerant leaks, such as high-pressure pipes or liquid pipes. Therefore, it is assumed that the refrigerant leaks through high-pressure pipes. Since the amount of refrigerant leakage is proportional to the differential pressure to the 0.5th power from Bernoulli's theorem, which is generally known in fluid mechanics, the amount of refrigerant leakage is 7.2 × 10 ^{−. 6} [m ³ / s] / (5/1) ^0.5 = 3.2 × 10 ⁻⁶ , and if the leakage is less than this value, it is safe. Therefore, for further safety, the amount of leakage shall be suppressed to 1.0 × 10 ⁻⁶ [m ³ / s] or less.
The first operating device 37 and the second operating device 38 may have a minimum operating pressure difference of, for example, about 0 (kgf / cm ² ).

  When the heat source side refrigerant leaks from the flow path (refrigerant circulation circuit A) through which the heat source side refrigerant circulates, the refrigerant concentration outside (refer to the outdoor space 6, indoor space 7 and space 8 in FIG. 1) corresponding to the leakage increases. To do. The resistance value of the detection member of the concentration detector 39 changes according to the concentration of the leaked refrigerant. Based on the resistance value, the concentration calculation unit 41 calculates the concentration of the leaked refrigerant.

  When the calculation result of the concentration calculation unit 41 is less than a predetermined concentration value that is not regarded as refrigerant leakage, the concentration detection unit 39 does not output a predetermined signal to the cutoff control device 40. Accordingly, since the predetermined signal is not output to the shutoff control device 40, the shutoff control device 40 maintains the electrical connection between the voltage source and the first shutoff device 37 and the second shutoff device 38. That is, voltage is supplied from the voltage source to the coils of the first cutoff device 37 and the second cutoff device 38. Thereby, the valve body of the 1st cutoff device 37 and the 2nd cutoff device 38 maintains the open state. That is, both the 1st cutoff device 37 and the 2nd cutoff device 38 will be in an open state.

If the calculation result of the concentration calculation unit 41 is equal to or greater than a predetermined concentration value that is regarded as refrigerant leakage, the concentration detection unit 39 outputs a predetermined signal to the cutoff control device 40. Based on this output (predetermined signal), the shutoff control device 40 shuts off the electrical connection between the voltage source and the first shutoff device 37 and the second shutoff device 38. That is, no voltage is supplied from the voltage source to the coils of the first cutoff device 37 and the second cutoff device 38. Thereby, the valve body of the 1st cutoff device 37 and the 2nd cutoff device 38 closes. That is, both the 1st cutoff device 37 and the 2nd cutoff device 38 will be in a closed state.
Thereby, the flow of the refrigerant flowing out of the outdoor unit 1 and the flow of the refrigerant flowing into the outdoor unit 1 are blocked. That is, it is suppressed that the heat source side refrigerant circulates in the refrigerant circuit A. Thereby, since the quantity which a refrigerant | coolant leaks is reduced, the safety | security of the air conditioning apparatus 100 can be improved.

[Indoor unit 2]
The indoor unit 2 includes use side heat exchangers 26a to 26d (also simply referred to as use side heat exchangers 26). The use-side heat exchanger 26 includes heat medium flow control devices 25 a to 25 d (also simply referred to as heat medium flow control devices 25) via the heat medium pipe 5 and second heat via the heat medium pipe 5. It connects with the medium flow path switching devices 23a-23d (it may only be called the 2nd heat medium flow path switching device 23). The use-side heat exchanger 26 performs heat exchange between air supplied from a blower such as a fan (not shown) and a heat medium, and generates heating air or cooling air to be supplied to the indoor space 7. To do.

  In FIG. 2, the case where four indoor units 2a to 2d are connected to the heat medium relay unit 3 via the heat medium pipe 5 is shown as an example. Further, in accordance with the indoor units 2a to 2d, the use side heat exchanger 26 also has a use side heat exchanger 26a, a use side heat exchanger 26b, a use side heat exchanger 26c, and a use side heat exchanger 26d from the lower side of the drawing. And Note that the number of connected indoor units 2 is not limited to four.

[Heat medium converter 3]
The heat medium relay 3 includes two heat medium heat exchangers 15a and 15b (sometimes simply referred to as the heat medium heat exchanger 15) and two expansion devices 16a and 16b (also simply referred to as the expansion device 16). Two open / close devices 17a and 17b (also simply referred to as open / close device 17) and two second refrigerant flow switching devices 18a and 18b (also simply referred to as second refrigerant flow switching device 18). Two pumps 21a and 21b (also simply referred to as pump 21) and four first heat medium flow switching devices 22a to 22d (also simply referred to as first heat medium flow switching device 22). And four second heat medium flow switching devices 23a to 23d (also simply referred to as second heat medium flow switching device 23) and four heat medium flow control devices 25a to 25d (simply simply). Heat medium flow And also) be referred to as an adjustment device 25, it is mounted.

  The heat exchanger related to heat medium 15 (load side heat exchanger) functions as a condenser (heat radiator) or an evaporator, performs heat exchange between the heat source side refrigerant and the heat medium, and is generated by the outdoor unit 1 and is generated on the heat source side. The cold or warm heat stored in the refrigerant is transmitted to the heat medium. The heat exchanger related to heat medium 15a is connected between pipes connecting the expansion device 16a and the second refrigerant flow switching device 18a in the refrigerant circuit A shown in FIG. At times, the heat medium is cooled. The heat exchanger related to heat medium 15b is connected between pipes connecting the expansion device 16b and the second refrigerant flow switching device 18b in the refrigerant circuit A shown in FIG. Sometimes the heating medium is heated.

  The expansion device 16 has a function as a pressure reducing valve or an expansion valve, and expands 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 expansion device 16 may be configured by a device whose opening degree can be variably controlled, for example, an electronic expansion valve.

  The opening / closing device 17 opens and closes the flow path in which it is provided. The opening / closing device 17a is provided on the upstream side of the expansion device 16 in the flow of the heat source side refrigerant in the cooling only operation mode. The opening / closing device 17b is provided on the downstream side of the expansion device 16a in the flow of the heat source side refrigerant in the heating only operation mode. The opening / closing device 17 may be constituted by, for example, a two-way valve.

  The second refrigerant flow switching device 18 switches the refrigerant flow during the heating only operation mode, the refrigerant flow during the cooling only operation mode, and the refrigerant flow during the cooling / heating mixed operation mode. The second refrigerant flow switching device 18b is configured to connect the high-pressure side refrigerant pipe 4a (2) and the heat exchanger related to heat medium 15b in the heating only operation mode. The second refrigerant flow switching device 18a is configured to connect the heat exchanger related to heat medium 15a and the low-pressure side refrigerant pipe 4b (2) in the cooling only operation mode and the cooling / heating mixed operation mode. The second refrigerant flow switching device 18 may be constituted by a four-way valve or the like, for example.

  The pump 21 circulates the heat medium flowing through the heat medium pipe 5. The pump 21 a is connected between pipes connecting the heat exchanger 15 a between heat exchangers 15 a and the second heat medium flow switching device 23 in the heat medium pipe 5. The pump 21 b is connected between pipes connecting the heat exchanger related to heat medium 15 b and the second heat medium flow switching device 23 in the heat medium pipe 5. The two pumps 21 may be constituted by, for example, pumps capable of capacity control. In addition, you may connect the pump 21a between the piping which connects the heat exchanger 15a between heat mediums 15a and the 1st heat medium flow switching device 22 among the heat medium piping 5. FIG. Moreover, you may connect the pump 21b between the piping which connects the heat exchanger 15b between heat exchangers 15b and the 1st heat carrier flow switching apparatus 22 among the heat carrier piping 5. FIG.

  The first heat medium flow switching device 22 switches the flow path of the heat medium. The first heat medium flow switching device 22 is provided in a number (here, four) according to the number of indoor units 2 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 26. In correspondence with the indoor unit 2, the first heat medium flow switching device 22a, the first heat medium flow switching device 22b, the first heat medium flow switching device 22c, and the first heat medium flow from the lower side of the drawing. The switching device 22d is assumed. The first heat medium flow switching device 22 may be configured with, for example, a three-way valve.

  The second heat medium flow switching device 23 switches 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. The heat exchanger is connected to the exchanger 26 and provided on the inlet side of the heat medium flow path of the use side heat exchanger 26. In correspondence with the indoor unit 2, the second heat medium flow switching device 23a, the second heat medium flow switching device 23b, the second heat medium flow switching device 23c, and the second heat medium flow from the lower side of the drawing. It is assumed that the switching device 23d. The second heat medium flow switching device 23 may be constituted by, for example, a three-way valve.

  The heat medium flow control device 25 adjusts the flow rate of the heat medium flowing through the heat medium pipe 5. 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, and is connected to the outlet side of the heat medium flow channel of the use-side heat exchanger 26. Is provided. In correspondence with the indoor unit 2, the heat medium flow adjustment device 25 a, the heat medium flow adjustment device 25 b, the heat medium flow adjustment device 25 c, and the heat medium flow adjustment device 25 d are illustrated from the lower side of the drawing. 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 flow control device 25 may be composed of, for example, a two-way valve that can control the opening area.

  Further, the heat medium relay 3 includes various detection means (in FIG. 5, two first temperature sensors 31a and 31b, four second temperature sensors 34a to 34d, four third temperature sensors 35a to 35d, and A pressure sensor 36) is provided. Information (temperature information, pressure information) detected by these various detection means is sent to a control device (not shown) that performs overall control of the operation of the air conditioner 100, and the drive frequency of the compressor 10, heat source side heat exchange. The rotation speed of a blower (not shown) provided near the heat exchanger 12 and the use-side heat exchanger 26, switching of the first refrigerant flow switching device 11, driving frequency of the pump 21, switching of the second refrigerant flow switching device 18, heat This is used for control such as switching of the flow path of the medium circuit.

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

  The four second temperature sensors 34 a to 34 d (also simply referred to as the second temperature sensor 34) are provided between the first heat medium flow switching device 22 and the heat medium flow control device 25. The temperature of the heat medium flowing out from the use side heat exchanger 26 is detected. The number of the second temperature sensors 34 (four here) according to the number of indoor units 2 installed is provided. In correspondence with the indoor unit 2, the second temperature sensor 34a, the second temperature sensor 34b, the second temperature sensor 34c, and the second temperature sensor 34d are illustrated from the lower side of the drawing. The second temperature sensor 34 may be composed of, for example, a thermistor.

  The four third temperature sensors 35a to 35d (also simply referred to as the third temperature sensor 35) are provided on the inlet side or the outlet side of the heat source side refrigerant in the heat exchanger related to heat medium 15, The temperature of the heat source side refrigerant flowing into the intermediate heat exchanger 15 or the temperature of the heat source side refrigerant flowing out of the intermediate heat exchanger 15 is detected. 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 third temperature sensor 35 may be composed of, for example, a thermistor.

  Similar to the installation position of the third temperature sensor 35d, the pressure sensor 36 is provided between the heat exchanger related to heat medium 15b and the expansion device 16b, and between the heat exchanger related to heat medium 15b and the expansion device 16b. The pressure of the flowing heat source side refrigerant is detected.

  Also, a main controller (not shown) is configured by a microcomputer or the like, and based on detection information from various detection means and instructions from a remote controller, the driving frequency of the compressor 10 and the blower (not shown) Rotational speed (including ON / OFF), switching of the first refrigerant flow switching device, driving of the pump 21, opening of the expansion device 16, opening / closing of the opening / closing device 17, switching of the second refrigerant flow switching device 18, first The switching of the heat medium flow switching device 22, the switching of the second heat medium flow switching device 23, the opening degree of the heat medium flow control device 25, and the like are controlled, and each operation mode described later is executed. Yes. Note that the control device may be provided for each unit, or may be provided in the outdoor unit 1 or the heat medium relay unit 3.

  The heat medium pipe 5 through which the heat medium flows 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 heat medium pipe 5 is branched (here, four branches each) according to the number of indoor units 2 connected to the heat medium converter 3. The heat medium pipe 5 is connected to the first heat medium flow switching device 22 and the 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 set.

  In the air conditioner 100, the flow of the heat source side refrigerant among the compressor 10, the first refrigerant flow switching device 11, the heat source side heat exchanger 12, the switching device 17, the expansion device 16, and the heat exchanger related to heat medium 15. The refrigerant circulation circuit A is configured by connecting the passage, the second refrigerant flow switching device 18 and the accumulator 19 with the refrigerant pipe 4. Further, the heat medium flow path of the intermediate heat exchanger 15, 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 the heat medium pipe 5 to constitute the 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.

  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.

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

  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. 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 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 only in the use side heat exchanger 26a and the use side heat exchanger 26b. 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 converter 3, the pump 21a and the pump 21b are driven, the heat medium flow control device 25a and the heat medium flow control device 25b are opened, and the heat medium flow control device 25c and the heat medium flow control device 25d are fully closed. The heat medium is circulated between each of the heat exchanger related to heat medium 15a and the second heat exchanger related to heat medium 15b and the use side heat exchanger 26a and the use side heat exchanger 26b.

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 liquid refrigerant that has flowed out of the heat source-side heat exchanger 12 flows out of the outdoor unit 1 through the pipe provided with the check valve 13a and the high-pressure side refrigerant pipe 4a (1), and the high-pressure side refrigerant pipe 4a (2 ) To the heat medium relay unit 3.
The high-pressure liquid refrigerant flowing into the heat medium relay unit 3 is branched after passing through the opening / closing device 17a and 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.

The low-temperature / low-pressure 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. The low-temperature / low-pressure two-phase refrigerant absorbs heat from the heat medium circulating in the heat medium circuit B and becomes a low-temperature / low-pressure gas refrigerant while cooling the heat medium.
The gas refrigerant flowing out from the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b flows out from the heat medium converter 3 via the second refrigerant flow switching device 18a and the second refrigerant flow switching device 18b. Then, it flows into the outdoor unit 1 again through the low-pressure side refrigerant pipe 4b (2).
The gas refrigerant flowing into the outdoor unit 1 is sent to the compressor 10 via the low-pressure side refrigerant pipe 4b (1), the pipe connected to the check valve 13d, the first refrigerant flow switching device 11, and the accumulator 19. Inhaled again.

  The aperture of the expansion device 16a is controlled so that the superheat (superheat degree) obtained as the difference between the temperature detected by the third temperature sensor 35a and the temperature detected by the third temperature sensor 35b is constant. . 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 all-cooling operation mode, the cold heat of the heat source side refrigerant is transmitted to the heat medium in both the heat exchangers between heat exchangers 15a and 15b, and the cooled heat medium is transferred by the pumps 21a and 21b. The inside of the heat medium pipe 5 is 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 23b, and the use side heat exchanger 26a and the use side heat exchange. Flows into the vessel 26b. The heat medium absorbs heat from the indoor air in the use side heat exchanger 26a and the use side heat exchanger 26b, 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 26b and flows into the heat medium flow control device 25a and the heat medium flow control device 25b. At this time, the heat medium flow control device 25a and the heat medium flow control device 25b 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. And it flows into the use side heat exchanger 26b.
The heat medium flowing out from the heat medium flow control device 25a passes through the first heat medium flow switching device 22a, flows into the heat exchanger related to heat medium 15a and the heat exchanger related to second heat medium 15b, and is again pump 21a. And sucked into the pump 21b.

  In addition, in the heat medium pipe 5 of the use side heat exchanger 26, 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 includes the temperature detected by the first temperature sensor 31a, the temperature detected by the first temperature sensor 31b, and the temperature detected by the second temperature sensor 34. By controlling so as to keep the difference between the two as a target value, it can be covered. As the outlet temperature of the heat exchanger related to heat medium 15, either the first temperature sensor 31a or the first temperature sensor 31b may be used, or the average temperature of these may be used. At this time, the first heat medium flow switching device 22 and the second heat medium flow switching device 23 have a flow path that flows to both the heat medium heat exchanger 15a and the second heat medium heat exchanger 15b. As shown in FIG.

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, a heat medium flows because there is a heat load in the use side heat exchanger 26a and the use side heat exchanger 26b. However, in the use side heat exchanger 26c and the use side heat exchanger 26d, the heat load is supplied. The corresponding heat medium flow control device 25c and heat medium flow control device 25d are fully closed. When a heat load is generated from the use side heat exchanger 26c or the use side heat exchanger 26d, the heat medium flow control device 25c or the heat medium flow control device 25d is opened to circulate the heat medium. That's fine.
This operation may be applied similarly in other operation modes.

[Heating operation mode]
FIG. 4 is a refrigerant circuit diagram illustrating a refrigerant flow when the air-conditioning apparatus 100 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 only in the use side heat exchanger 26a and the use side heat exchanger 26b. In FIG. 4, the pipes represented by the thick lines indicate the pipes through which the refrigerant (heat source side refrigerant and heat medium) 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 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 device 25a and the heat medium flow control device 25b are opened, and the heat medium flow control device 25c and the heat medium flow control device 25d are fully closed. The heat medium circulates between the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b and the use side heat exchanger 26a and the use side heat exchanger 26b.

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, the first connection pipe 42a, and the refrigerant pipe 4a (1). 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 high-pressure side refrigerant pipe 4a (2). The high-temperature and high-pressure gas refrigerant that has flowed into the heat medium relay unit 3 is branched and passed through the second refrigerant flow switching device 18a and the second refrigerant flow switching device 18b, and the heat exchanger related to heat medium 15a and the heat medium. It flows into each of the intermediate heat exchangers 15b.

  The high-temperature and high-pressure gas refrigerant that has flowed into the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b becomes a high-pressure refrigerant whose temperature has decreased 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, low-pressure two-phase refrigerant. The low-temperature / low-pressure 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 again through the low-pressure side refrigerant pipe 4b (2). The opening / closing device 17a is closed and the opening / closing device 17b is open.

The refrigerant that has flowed into the outdoor unit 1 flows into the heat source side heat exchanger 12 that functions as an evaporator via the low-pressure side refrigerant pipe 4b (1) and the second connection pipe 42b. 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 and 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.
In addition, although the refrigerant | coolant which flowed in into the low voltage | pressure side refrigerant | coolant piping 4b (1) flows into the 2nd connection piping 42b side (check valve 13c), it does not flow into the check valve 13d. This is because the refrigerant flowing on the point P1 side shown in FIG. 4 has a higher pressure than the refrigerant flowing on the point P3 side, and the check valve 13d is closed.
The refrigerant that has flowed into the second connection pipe 42b flows to the heat source side heat exchanger 12, but does not flow to the check valve 13a. This is because the refrigerant flowing on the point P4 side shown in FIG. 4 has a higher pressure than the refrigerant flowing on the point P2 side, and the check valve 13a is closed.

  The expansion device 16a is opened so that a subcool (degree of subcooling) obtained as a difference between a value obtained by converting the pressure detected by the pressure sensor 36 into a saturation temperature and a temperature detected by the third temperature sensor 35b is constant. The degree is controlled. Similarly, 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 pressure sensor 36 into a saturation temperature and a temperature detected by the third temperature sensor 35d is constant. Be controlled. When 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 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 heated by the pump 21a and the pump 21b. The inside of the pipe 5 is 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 23b, and the use side heat exchanger 26a and the use side heat exchange. Flows into the vessel 26b. The heat medium radiates heat to the indoor air in the use side heat exchanger 26a and the use side heat exchanger 26b, thereby heating the indoor space 7.

  Then, the heat medium flows out of the use side heat exchanger 26a and the use side heat exchanger 26b and flows into the heat medium flow control device 25a and the heat medium flow control device 25b. At this time, the heat medium flow control device 25a and the heat medium flow control device 25b 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. And it flows into the use side heat exchanger 26b. The heat medium flowing out from the heat medium flow control device 25a and the heat medium flow control device 25b passes through the first heat medium flow switching device 22a and the first heat medium flow switching device 22b, 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 addition, in the heat medium pipe 5 of the use side heat exchanger 26, 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 includes the temperature detected by the first temperature sensor 31a, the temperature detected by the first temperature sensor 31b, and the temperature detected by the second temperature sensor 34. By controlling so as to keep the difference between the two 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 26a 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.

[Cooling operation mode]
FIG. 5 is a refrigerant circuit diagram illustrating a refrigerant flow when the air-conditioning apparatus 100 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 cooling load is generated in the use side heat exchanger 26a and a heating load is generated in the use side heat exchanger 26b. 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 device 25a and the heat medium flow control device 25b are opened, and the heat medium flow control device 25c and the heat medium flow control device 25d are fully closed. The heat medium is circulated between the heat exchanger related to heat medium 15a and the use side heat exchanger 26a, and between the heat exchanger related to heat medium 15b and the use side heat exchanger 26b.

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 high-pressure liquid refrigerant that has flowed out of the heat source-side heat exchanger 12 flows out of the outdoor unit 1 through the pipe provided with the check valve 13a and the high-pressure side refrigerant pipe 4a (1), and the high-pressure side refrigerant pipe 4a (2 ) To the heat medium relay unit 3. The high-pressure liquid 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 opening / closing device 17 is closed.

  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 from the heat exchanger related to heat medium 15b is expanded by the expansion device 16b and becomes a low-pressure two-phase refrigerant. The 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 that has flowed 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 returns to the outdoor unit 1 again via the low-pressure side refrigerant pipe 4b (2). Inflow. The refrigerant flowing into the outdoor unit 1 is again supplied to the compressor 10 via the low-pressure side refrigerant pipe 4b (1), the pipe provided with the check valve 13d, the first refrigerant flow switching device 11, and the accumulator 19. Inhaled.

  The aperture 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 is constant. The expansion device 16a is fully open, and the opening / closing device 17a and the opening / closing device 17b are closed. The expansion device 16b controls the opening degree so that a subcool obtained as a difference between a value obtained by converting the pressure detected by the pressure sensor 36 into a saturation temperature and a temperature detected by the third temperature sensor 35d is constant. May be. 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 heat medium pipe 5 by the pump 21b. Further, in the cooling main operation mode, the cold heat of the heat source side refrigerant is transmitted to the heat medium in the heat exchanger related to heat medium 15a, and the cooled heat medium is caused to flow in the heat medium pipe 5 by the pump 21a. 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 23b, and the use side heat exchanger 26a and the use side heat exchange. Flows into the vessel 26b.

  In the use side heat exchanger 26b, 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 heat medium flow control device 25a and the heat medium flow control device 25b 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. And it flows into the use side heat exchanger 26b. The heat medium whose temperature has slightly decreased after passing through the use side heat exchanger 26b flows into the heat exchanger related to heat medium 15b through the heat medium flow control device 25b and the first heat medium flow switching device 22b, 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 is introduced into the heat exchanger 26. In the heat medium pipe 5 of the use side heat exchanger 26, 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. 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.

[Heating main operation mode]
FIG. 6 is a refrigerant circuit diagram showing a refrigerant flow when the air-conditioning apparatus 100 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 use side heat exchanger 26a and a cold load is generated in the use side heat exchanger 26b. 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 device 25a and the heat medium flow control device 25b are opened, and the heat medium flow control device 25c and the heat medium flow control device 25d are fully closed. The heat medium circulates between the heat exchanger related to heat medium 15a and the use-side heat exchanger 26b, and between the heat exchanger related to heat medium 15b and the use-side heat exchanger 26a.

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, the first connection pipe 42a, and the refrigerant pipe 4a (1). 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 high-pressure side refrigerant pipe 4a (2). 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 via the second refrigerant flow switching device 18b. The opening / closing device 17 is closed.

  The gas refrigerant that has flowed into the heat exchanger related to heat medium 15b becomes a refrigerant whose temperature has dropped in a supercritical state while radiating heat to the heat medium circulating in the heat medium circuit B. The refrigerant flowing out from the heat exchanger related to heat medium 15b is expanded by the expansion device 16b and becomes a low-pressure two-phase refrigerant. The 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 flowing 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. This low-pressure two-phase 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 passes through the low-pressure side refrigerant pipe 4b (2). It flows into the outdoor unit 1 again.

  The refrigerant that has flowed into the outdoor unit 1 flows into the heat source side heat exchanger 12 that functions as an evaporator via the low-pressure side refrigerant pipe 4b (1) and the second connection pipe 42b. 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 and 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.

  The opening degree of the expansion device 16b is controlled so that the subcool obtained as a difference between the value detected by the pressure sensor 36 and converted into the saturation temperature and the temperature detected by the third temperature sensor 35b is constant. . Further, the expansion device 16a is fully opened and the opening / closing device 17b is 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 heat medium 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 in the heat exchanger related to heat medium 15a, and the cooled heat medium is caused to flow in the heat medium pipe 5 by the pump 21a. 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 23b, and the use side heat exchanger 26a and the use side heat exchange. Flows into the vessel 26b.

  In the use side heat exchanger 26b, the heat medium absorbs heat from the indoor air, thereby cooling the indoor space 7. Moreover, in the use side heat exchanger 26a, 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 25b 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. And it flows into the use side heat exchanger 26b. The heat medium whose temperature has slightly increased after passing through the use side heat exchanger 26b flows into the heat exchanger related to heat medium 15a through the heat medium flow control device 25b and the first heat medium flow switching device 22b, 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 26a flows into the heat exchanger related to heat medium 15b 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 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 26. In the heat medium pipe 5 of the use side heat exchanger 26, 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. 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.

[Refrigerant piping 4]
As described above, the air conditioner 100 according to the present embodiment has several operation modes. In these operation modes, the heat source side refrigerant flows through the refrigerant pipe 4 that connects the outdoor unit 1 and the heat medium relay unit 3.

[Heat medium piping 5]
In some operation modes executed by the air-conditioning apparatus 100 according to the present embodiment, a heat medium such as water or antifreeze flows through the heat medium pipe 5 that connects the heat medium converter 3 and the indoor unit 2. .

[Heat source side refrigerant]
In the air conditioning apparatus 100 according to the present embodiment, it is assumed that a refrigerant having a small global warming potential is employed as the heat source side refrigerant. Examples of such a refrigerant include HFO1234yf, a mixed refrigerant of HFO1234yf, HFO1234ze, other tetrafluoropropene refrigerants, R32, HC, carbon dioxide, a mixed refrigerant containing at least one component of the above-described refrigerant.

[Heat medium]
As the heat medium, for example, brine (antifreeze), water, a mixed solution of brine and water, a mixed solution of water and an additive having a high anticorrosive effect, or the like can be used. Therefore, in the air conditioning apparatus 100, even if the heat medium leaks into the indoor space 7 through the indoor unit 2, it contributes to the improvement of safety because a highly safe heat medium is used. Become.

  The air conditioner 100 employing the configuration as described above 2 can detect refrigerant leakage from the refrigerant circuit (refrigerant circulation circuit A), and greatly improves safety. Moreover, since the air conditioning apparatus 100 uses what changed to a supercritical state for a refrigerant | coolant, it can reduce environmental impact.

  Although the air conditioning apparatus 100 has been described as being capable of performing mixed cooling and heating operations, the present invention is not limited to this. For example, there is one heat exchanger 15 between the heat medium and one expansion device 16, and a plurality of use side heat exchangers 26 and heat medium flow control devices 25 are connected in parallel to either the cooling operation or the heating operation. The present invention can be applied even to configurations that can only be performed.

  Further, the present invention can be applied even when only one use-side heat exchanger 26 and the heat medium flow control device 25 are connected. Furthermore, it goes without saying that a plurality of heat exchangers 15 and the expansion device 16 that move in the same manner may be installed. Further, the case where the heat medium flow control device 25 is built in the heat medium converter 3 has been described as an example. However, the heat medium flow control device 25 is not limited thereto, and may be built in the indoor unit 2. 3 and the indoor unit 2 may be configured separately.

  In general, the heat source side heat exchanger 12 and the use side heat exchanger 26 are provided with a blower, and in many cases, condensation or evaporation is promoted by blowing air, but this is not restrictive. For example, the use side heat exchanger 26 may be a panel heater using radiation, and the heat source side heat exchanger 12 is of a water-cooled type that moves heat by water or antifreeze. Can also be used. That is, the heat source side heat exchanger 12 and the use side heat exchanger 26 can be used regardless of the type as long as they have a structure capable of radiating heat or absorbing heat.

  In the air conditioning apparatus 100 according to the present embodiment, the case where there are four use-side heat exchangers 26 has been described as an example, but the number is not particularly limited. Moreover, although the case where the number of heat exchangers between heat media 15 is two has been described as an example, the number of heat exchangers is naturally not limited to this. If the heat medium can be cooled or / and heated, the number of heat exchangers 15 may be set. Also good. Furthermore, the number of pumps 21a and 21b is not limited to one, and a plurality of small-capacity pumps may be connected in parallel.

FIG. 8 shows another refrigerant circuit configuration example of the air-conditioning apparatus 100 according to the embodiment of the present invention. The difference between the refrigerant circuit of FIG. 8 and FIG. 2 to FIG. 6 is that it is a directly expanded air conditioner that does not have the heat medium circulation circuit B. Further, four aperture devices 14a to 14d are provided. Also in the air conditioner 100 having this configuration, the same functions as those in FIGS. There is an effect.
Although the example in which the concentration detection unit 39 is disposed in or near the outdoor unit 1 (heat source unit) has been described so far, the concentration detection unit 39 may be disposed in or near the indoor unit 2. Good. Thereby, it is possible to cope with refrigerant leakage of the indoor unit 2.

  DESCRIPTION OF SYMBOLS 1 Outdoor unit, 2 Indoor unit, 2a-2d Indoor unit, 3 Heat transfer medium converter, 4 Refrigerant piping, 4a (1), 4a (2) High pressure side refrigerant piping, 4b (1), 4b (2) Low pressure side refrigerant Piping, 5 Heat medium piping, 6 Outdoor space, 7 Indoor space, 8 Space, 9 Building, 10 Compressor, 11 First refrigerant flow switching device, 12 Heat source side heat exchanger, 13a-13d Check valve, 15 Heat Inter-medium heat exchanger, 14a to 14d Throttle device, 15a, 15b Inter-heat medium heat exchanger, 16 Throttle device, 16a, 16b Throttle device, 17 Open / close device, 17a, 17b Open / close device, 18 Second refrigerant flow switching device , 18a, 18b second refrigerant flow switching device, 19 accumulator, 21 pump, 21a, 21b pump, 22 first heat medium flow switching device, 22a-22d first heat medium flow switching device, 23 second heat Medium flow path switching device, 23a to 23d Second heat medium flow path switching device, 25 Heat medium flow rate adjustment device, 25a to 25d Heat medium flow rate adjustment device, 26 Usage side heat exchanger, 26a to 26d Usage side heat exchanger, 31 1st temperature sensor, 31a, 31b 1st temperature sensor, 34 2nd temperature sensor, 34a-34d 2nd temperature sensor, 35 3rd temperature sensor, 35a-35d 3rd temperature sensor, 36 Pressure sensor, 37 1st interruption | blocking Device, 38 second shut-off device, 39 concentration detection unit, 40 shut-off control device, 41 concentration calculation unit, 42a first connection piping, 42b second connection piping, 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 throttling device, and a load side heat exchanger, which are connected to each other by a refrigerant pipe and have a refrigeration cycle. A blocking device that passes or blocks the refrigerant circulating in the refrigeration cycle, a detection unit that detects a resistance value that varies according to the concentration of the plurality of leaked refrigerants, and a refrigerant that leaks based on the resistance value of the detection unit A concentration calculation unit that calculates a concentration, a concentration detection unit that outputs a calculation result of the concentration calculation unit for use in controlling the cutoff device, and a cutoff control device that controls the cutoff device based on the output of the concentration detection unit If, have at least R410A, R407C, R32, R404A, HFO1234yf, mixed refrigerant and a HFO1234ze, R32 and HFO1234yf, and either the coolant All mixed refrigerant containing components, those that allow detection at the same detection unit.

The first refrigerant flow switching device 11 includes a discharge side of the compressor 10, a check valve 13b, a heat source side heat exchanger 12, and an accumulator in the heating only operation mode and the heating main operation mode of the mixed heating and cooling operation mode. 19 suction sides are connected. The first refrigerant flow switching device 11, in the cooling main operation mode of the cooling only operation mode and heating mixed operation mode, the discharge side and the heat source-side heat exchanger 12 of the compressor 10, and a check valve 13d The suction side of the accumulator 19 is connected. The first refrigerant flow switching device 11 may be configured with, for example, a four-way valve.

On the other hand, when the refrigerant concentration is less than the predetermined concentration value, a predetermined signal is not output from the concentration detection unit 39 to the cutoff control device 40. Thereby, a voltage source (illustration omitted) and the 1st cutoff device 37 and the 2nd cutoff device 38 are electrically connected. That is, a voltage is supplied (powered) from the voltage source to the first cutoff device 37 and the second cutoff device 38. Then, since the coils of the first shut-off device 37 and the second shut-off device 38 are excited, the valve body is opened. That is, both the 1st cutoff device 37 and the 2nd cutoff device 38 will be in an open state.
The position at which the shutoff control device 40 is provided is not particularly limited, but may be installed in, for example, the outdoor unit 1 or in the vicinity of the outdoor unit 1.

When a mechanical electromagnet relay is used to switch the electrical connection between the voltage source and the first shut-off device 37 and the second shut-off device 38, a combustible refrigerant (HFO1234yf, R32, HC) is adopted as the refrigerant. In such a case, sparks may be generated and the refrigerant may be ignited. Therefore, it is preferable if the flammable refrigerant is employed, employing a to the blocking control device 40 is a non-contact relay using the semiconductor device S S R (Solid State Relay). Thereby, since there is no mechanical operation | movement, possibility that a spark will generate | occur | produce can be reduced. Thereby, even if a combustible refrigerant | coolant leaks to the outdoor unit 1, the electrical connection of a voltage source and the 1st cutoff device 37 and the 2nd cutoff device 38 can be switched safely.

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 converter 3, the pump 21a and the pump 21b are driven, the heat medium flow control device 25a and the heat medium flow control device 25b are opened, and the heat medium flow control device 25c and the heat medium flow control device 25d are fully closed. , the heat medium between the respective heat exchanger on the application side 26a and the use-side heat exchanger 26b of the heat medium heat exchanger 15a及beauty heat medium heat exchanger 15b is to circulate.

Next, the flow of the heat medium in the heat medium circuit B will be described.
In the full cooling operation mode, cold heat source-side refrigerant is transferred to the heat medium in both the heat medium heat exchanger 15a及beauty heat medium heat exchanger 15b, the cooled heat medium pump 21a and pump 21b heat The medium pipe 5 is 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 23b, and the use side heat exchanger 26a and the use side heat exchange. Flows into the vessel 26b. The heat medium absorbs heat from the indoor air in the use side heat exchanger 26a and the use side heat exchanger 26b, 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 26b and flows into the heat medium flow control device 25a and the heat medium flow control device 25b. At this time, the heat medium flow control device 25a and the heat medium flow control device 25b 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. And it flows into the use side heat exchanger 26b.
Heat medium flowing out of the heat medium flow rate control device 25a passes through the first heat medium flow switching device 22a, it flows into the heat medium heat exchanger 15a及beauty heat medium heat exchanger 15b, the pump 21a and again It is sucked into the pump 21b.

In addition, in the heat medium pipe 5 of the use side heat exchanger 26, 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 includes the temperature detected by the first temperature sensor 31a, the temperature detected by the first temperature sensor 31b, and the temperature detected by the second temperature sensor 34. By controlling so as to keep the difference between the two as a target value, it can be covered. As the outlet temperature of the heat exchanger related to heat medium 15, either the first temperature sensor 31a or the first temperature sensor 31b may be used, or the average temperature of these may be used. In this case, the first heat medium flow switching device 22 and the second heat medium flow switching device 23, a flow path that flows to both the heat medium heat exchanger 15a及beauty heat medium heat exchanger 15b is secured Thus, the intermediate opening is set.

An air conditioner according to the present invention includes a compressor, a heat source side heat exchanger, a throttling device, and a load side heat exchanger, which are connected to each other by a refrigerant pipe and have a refrigeration cycle. A blocking device that passes or blocks the refrigerant circulating in the refrigeration cycle, a detection unit that detects a resistance value that varies according to the concentration of the plurality of leaked refrigerants, a refrigerant concentration for each circulating refrigerant, and a resistance of the detection unit A concentration calculation unit that stores the relationship with the value and calculates the concentration of the refrigerant that has leaked based on the resistance value of the detection unit, and a concentration detection that outputs the calculation result of the concentration calculation unit for use in controlling the shut-off device And a shutoff control device that controls the shutoff device based on the output of the concentration detector, and at least R410A, R407C, R32, R404A, HFO1234yf, HFO1234ze, R32 Mixed refrigerant and a HFO1234yf, and all the mixed refrigerant containing any one component of the refrigerant, but that is to be detected by the same detection unit.

Claims (16)

In an air conditioner having a compressor, a heat source side heat exchanger, an expansion device, and a load side heat exchanger, and having a refrigeration cycle configured by connecting these with refrigerant piping,
A blocking device for passing or blocking the refrigerant circulating in the refrigeration cycle;
A detection unit that detects refrigerant leakage with a resistance value that varies according to the concentration of the plurality of types of refrigerant that has leaked;
A concentration calculator that calculates the concentration of the refrigerant that has leaked based on the resistance value of the detector;
A concentration detection unit that outputs the calculation result of the concentration calculation unit for use in controlling the shut-off device; and
A shutoff control device for controlling the shutoff device based on the output of the concentration detector;
An air conditioner characterized by comprising: The air conditioner according to claim 1, wherein the detection unit is made of a tin oxide (SnO ₂ ) semiconductor. All of the refrigerant mixture including at least R410A, R407C, R32, R404A, HFO1234yf, HFO1234ze, R32 and HFO1234yf, and the mixed refrigerant including any one component of the refrigerant can be detected by the same detection unit. The air conditioning apparatus according to claim 1, wherein: The concentration calculator
R410A, R407C, R32, HFO1234yf, HFO1234ze, R32 and HFO1234yf are mixed refrigerants, and all of the mixed refrigerants containing any one component of the refrigerant are used by using the same relational expression of resistance change and concentration change. The air-conditioning apparatus according to claim 3, wherein the refrigerant leakage concentration can be calculated. The concentration detector
The predetermined signal for shutting off the circulation of the refrigerant by the shut-off device is output to the shut-off control device when the calculation result of the refrigerant concentration of the concentration calculating unit is a predetermined value or more. The air conditioning apparatus as described in any one of -4. The air conditioning apparatus according to claim 5, wherein the predetermined signal is 1 (V) to 24 (V). An outdoor unit having the compressor and the heat source side heat exchanger;
The blocking device is
It is provided in the said outdoor unit or the vicinity of the said outdoor unit. The air conditioning apparatus as described in any one of Claims 1-6 characterized by the above-mentioned. The air-conditioning apparatus according to any one of claims 1 to 7, wherein the shut-off control device is a contactless relay including a semiconductor element. The air conditioner according to claim 1, wherein the shut-off device is in an open state when energized and closed in a non-energized state. The blocking device is
10. The air conditioner according to claim 7, wherein at least one or more refrigerant outlets are provided at a refrigerant outlet from the outdoor unit and a refrigerant inlet to the outdoor unit, respectively. The said shut-off device is a valve body, a sealing material for sealing the valve body, and the valve body is a two-way valve having an open / close coil by electromagnetic force. The air conditioning apparatus described. The air conditioning apparatus according to any one of claims 11 to 13, wherein the sealing material is made of rubber or PTFE (polytetrafluoroethylene). The blocking device is
Leakage of the heat-source-side refrigerant when the closed state ^{is, 1.0 × 10 -6 (m 3} / sec) air conditioning apparatus according to any one of claims 1 to 12, characterized in that less is . When the discharge side of the compressor is defined as upstream,
The flow coefficient Cv value of the shut-off device downstream of the heat exchanger related to heat medium among the shut-off devices is set to 1 or more,
The air conditioner according to any one of claims 1 to 13, wherein a flow coefficient Cv value of a shut-off device upstream of the heat exchanger related to heat medium among the shut-off devices is 5 or more. The air conditioning apparatus according to any one of claims 11 to 14, wherein a DC voltage is supplied to the coil. The direct current voltage supplied to the coil is 12 (V) to 24 (V).

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