JPS6196375A - Air-conditioning hot-water supply device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an air-conditioning, heating, and water supply system, and particularly to a heat pump that is capable of each operation of hot water supply, cooling, and heating, and is suitable for simultaneous operation of hot water supply and cooling, or hot water supply and heating. This relates to a type of air-conditioning/heating/water heating system.

[Background of the invention]

An example of an air-conditioning/heating/water supply device capable of performing cooling, heating, and hot water supply operations, as well as simultaneous operation of hot water supply, cooling, and hot water supply and heating, is a refrigeration cycle as described in Japanese Utility Model Publication No. 49-94269. .

According to the publication, it has a switching valve and first to fourth opening ends, respectively, and communicates the first opening end and the second opening end, or the eighth opening end and the fourth opening end, respectively, during hot water supply and cooling in the summer. The switching valve was moved to
A four-way valve is provided that moves the switching valve so that the open end and the fourth open end or the second open end and the third open end are communicated with each other, and the outlet of the compressor is connected to the first open end of the four-way valve for heat exchange for hot water supply. An Akicomulator is connected between the compressor and the second opening end of the four-way valve, and one end of the outdoor coil and one end of the indoor coil are connected to the eighth opening end and the fourth opening end of the four-way valve, respectively. Discloses the structure and operation of a heat pump type air conditioner for hot water supply and heating, in which a solenoid valve and a capillary tube are respectively connected in the middle of six pipes that connect a heat exchanger for hot water supply, an indoor coil, and the other end of an outdoor coil. has been done.

Furthermore, when only cooling is required in the summer, only the solenoid valve of the hot water heat exchanger is closed, when both hot water supply and cooling are used, only the solenoid valve for the external coil is closed, and furthermore, when only heating is required in the winter, the solenoid valve of the hot water heat exchanger is closed. By closing only the solenoid valve for the indoor coil and closing only the solenoid valve for the indoor coil when supplying hot water, you can extremely easily perform cooling and heating in the summer and winter, as well as hot water cooling and hot water supply, with a single air conditioner. This has extremely great practical effects.

However, the amount of refrigerant required in each operation mode is different, and it is difficult to obtain stable performance in each operation mode in the cycle of this hot water supply heat pump type air conditioner/heater. In other words, liquid refrigerant accumulates in heat exchangers or coils that are not used during cooling, heating, hot water supply, and cooling hot water supply operations.
Not enough consideration was given to the fact that the cycle would run out of refrigerant.

[Purpose of the invention]

The present invention has been made in order to solve the problems of the prior art described above, and includes various operations such as cooling, heating, and hot water supply, simultaneous cooling and hot water supply, heating and hot water supply, and defrosting operation. It is an object of the present invention to provide a heat pump type air-conditioning/heating/hot-water supply device that can prevent liquid refrigerant from accumulating in a heat exchanger that is sometimes in an unused state, and therefore can perform each operation efficiently.

[Summary of the invention]

The configuration of the air conditioning/heating/water supply device according to the present invention includes a compressor, a hot water supply heat exchanger, an air conditioning/heating heat exchanger, a heat source side heat exchanger, an Akicomulator, a first flow path switching valve capable of switching a refrigerant flow path in at least four directions, and at least The second part allows the refrigerant flow path to be switched to three directions.
flow path switching valve, first shutoff valve, second shutoff valve, eighth shutoff valve,
A refrigerant hot water supply device comprising a refrigeration cycle including a fourth shutoff valve, a first pressure reducing means, a second pressure reducing means, an eighth pressure reducing means, and refrigerant piping connecting these, wherein the first flow path switching valve is , a high pressure port that is always at high pressure is connected to the refrigerant discharge pipe of the compressor, a low pressure port that is always at low pressure is connected to the refrigerant suction pipe of the compressor through the accumulator, and a first port is connected to the refrigerant suction pipe of the compressor through the first shutoff valve. At one end of the heat source side heat exchanger,
Further, a second port is connected via piping to one end of the heating/cooling heat exchanger through the second shutoff valve, and a high pressure port of the second flow path switching valve, which is always at high pressure, is connected to the compressor and the high pressure port of the second flow path switching valve. A low pressure port that is always at low pressure is placed in the middle of the piping connecting the first flow path switching valve and the accumulator, and the remaining one port is connected to the hot water supply heat port. The second pressure reducing means is connected to one end of the exchanger through piping, and the other end of the hot water heat exchanger is connected to the other end of the heat source side heat exchanger, and the second pressure reducing means is arranged in parallel with the first pressure reducing means. The eighth shutoff valve is connected to the seventh shutoff valve via piping provided in series with the seventh shutoff valve, and the first
The eighth pressure reducing means and the fourth shutoff valve are arranged in parallel from the middle of the piping connecting the pressure reducing means and the second pressure reducing means and the eighth shutoff valve to the other end of the air conditioning heat exchanger. The refrigeration cycle is constructed by connecting the refrigeration cycle through piping.

Additionally, the idea behind developing the present invention is as follows.

The refrigeration cycle of the present invention is configured such that when each heat exchanger is not used in its respective operation mode, the pressure inside the heat exchanger is low. That is, since the unused heat exchanger is always connected to the low pressure side of the refrigeration cycle, the refrigerant is not condensed and liquefied here. Furthermore, if liquid refrigerant has accumulated, the refrigerant evaporates and is sucked into the compressor.

Therefore, according to the present invention, there is no shortage of working refrigerant due to condensation and accumulation of refrigerant in the unused heat exchanger, so sufficient performance can be obtained in each operation mode.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

First, FIG. 1 is a system diagram of a refrigeration cycle of an air-conditioning, heating, and hot-water supply apparatus according to an embodiment of the present invention.

In the figure, 1 is a compressor, 2 is a hot water heat exchanger, 3 is an air conditioning/heating heat exchanger, 4V′i heat source side heat exchanger, 5Vi accumulator, 6 is a first four-way valve related to the first flow path switching valve, 7 is a second four-way valve associated with the second flow path switching valve; 8 is an electronic expansion valve associated with the first field reduction means; 9 is a capillary tube associated with the second pressure reduction means; and 10 is a capillary associated with the eighth pressure reduction means. The tube, 11 is a first shutoff valve, 12 is a second shutoff valve, 18 is an eighth shutoff valve, and 14 is a fourth shutoff valve, and a refrigeration cycle is constituted by each of these devices and the refrigerant piping that connects them. There is.

Among the refrigerant pipes, 15 is a refrigerant discharge pipe of the compressor 1, and 16 is a refrigerant discharge pipe of the compressor 1.
shows the refrigerant suction pipe of the compressor 1.

The high-pressure port 6a of the first four-way valve 6, which is always at high pressure, is connected to the refrigerant discharge pipe 15 of the compressor 1, and the low-pressure port 6b, which is always at low pressure, is connected to the refrigerant suction pipe 16 of the Vi field compressor 1.
The first port 6C is connected to one end of the heat source side heat exchanger 9 through a pipe provided with a first shutoff valve 11, and the remaining second port 6d is connected to one end of the heat source side heat exchanger 9 through a pipe provided with a second shutoff valve 12 for cooling/heating heat exchange. It is connected to one end of the device 8.

A high-pressure port 7a of the second four-way valve 7, which is always at high pressure, is connected to a pipe tSa in the middle of the pipe connecting the refrigerant outlet of the compression@1 and the first four-way valve 6, and a low-pressure port 7b, which is always at low pressure. is connected to the middle of the pipe 16a connecting the first four-way valve 6 and the Akicomulator 5, and is connected to the first port 70.
is pipe-connected to the hot water heat exchanger 2, and the remaining second port 7d is closed.

The other end of the hot water heat exchanger 2 is connected to the heat source side heat exchanger 4 and other parts by piping each having an electronic expansion valve 8, a capillary tube 9 arranged in parallel, and an eighth shutoff valve 18 in series. connected to the end.

A capillary tube 10 and a fourth shutoff valve 18 are arranged in parallel from the middle of the piping connecting these electronic expansion valves 8 to the capillary tube 9 and the eighth shutoff valve 18 to the other end of the air conditioning heat exchanger 8. They are connected via piping equipped with a shutoff valve 14.

Each operating operation and effect of the air-conditioning, heating, and hot-water supply apparatus having such a configuration will be explained.

(1) Hot water supply operation During hot water supply operation, the second shutoff valve 12 is closed, the first shutoff valve 11, the eighth shutoff valve 18, and the fourth shutoff valve 14 are open, and the first four-way valve 6 is connected to the heat source. Refrigerant suction pipe 1 from side heat exchanger 4
The second four-way valve 7 is in a state in which refrigerant flows from the refrigerant discharge pipe 16 to the hot water heat exchanger 2.

Since the second shutoff valve 12 is in the closed state, the high temperature and high pressure refrigerant vapor discharged from the compressor 1 passes through the high pressure port 7a of the second four-way valve 7 and the first port 7C to the hot water heat exchanger 2. flows into. Here, the refrigerant vapor heats the hot water supply and supplies water to the outside, and the refrigerant itself is condensed and liquefied. The condensed and liquefied refrigerant is depressurized by the electronic expansion valve 8 and then passed through the eighth shutoff valve 18.
After flowing through the heat source side heat exchanger 4, the refrigerant absorbs heat from the air, etc., and the refrigerant itself evaporates to become low-pressure vapor.The refrigerant passes through the first port 5c of the first four-way valve 6 and the low-pressure port 61:l. It flows through the suction pipe 16 and passes through the accumulator 5 to the compressor 1.
and then the same cycle is repeated.

Although the air conditioning heat exchanger 8 is not in use, since the second shutoff valve 12 is closed, it does not communicate with the refrigerant discharge pipe 15 of the compressor 1, that is, the high pressure side, but communicates with the low pressure side. The pressure becomes low. Therefore, the refrigerant does not condense and liquefy and accumulate in the heating and cooling heat exchanger 8.

(2) Cooling operation In summer, during cooling operation, electronic expansion valve 8 and eighth shutoff valve 1
8 is in the closed state, the first shutoff valve 11, the second shutoff valve 12, the fourth shutoff valve
The shutoff valve 14 is in an open state.

The first four-way valve 6 is in a state where the refrigerant flows from the refrigerant discharge pipe 16 of the compressor 1 to the heat source side heat exchanger 4, and the refrigerant flows from the air conditioning heat exchanger 8 to the refrigerant suction pipe 16 of the compressor 1. , the second four-way valve 7 is in a state where the hot water supply heat exchanger 2 communicates with the low pressure side.

High-temperature, high-pressure refrigerant vapor discharged from the compressor 1 flows into the heat source side heat exchanger 4 through the refrigerant discharge pipe 16, the high-pressure port 6a of the first four-way valve 6, the first port 6C1, and the first shut-off valve 11. Here, the refrigerant vapor is cooled by air or the like and condensed into liquid. The condensed and liquefied refrigerant is depressurized by the capillary tube 9 associated with the second decompression means, flows back through the fourth shutoff valve 14, and then flows into the air conditioning heat exchanger 8, where it takes heat from the indoor air to increase the cooling effect. , the refrigerant itself evaporates. The evaporated low-pressure refrigerant vapor passes through the second shut-off valve 12, passes through the second port 6 (L, low-pressure port 6b) of the first four-way valve 6, flows through the refrigerant suction pipe 16, passes through the Akie emulator 5, and is sucked into the compressor 1. The same cycle is then repeated.

Although the hot water heat exchanger 2 is not in use, it is connected to the refrigerant suction pipe 16 side of the compressor 1, that is, the low pressure side, through the second four-way valve 7, so that the refrigerant is condensed and liquefied here. It never accumulates.

(8) Heating operation In winter, during heating operation, electronic expansion valve 8 and fourth shutoff valve 1
4 is in a closed state, and the first cutoff valve 11, second cutoff valve 12, and eighth cutoff valve 18 are in an open state.

The first four-way valve 6 is in a state where the refrigerant flows from the refrigerant discharge pipe 15 of the compressor 1 to the air conditioning heat exchanger 3, and from the heat source side heat exchanger 4 to the refrigerant suction pipe 16 of the engine A, Also,
The second four-way valve 7 is in a state where the hot water heat exchanger 2 communicates with the low pressure side, as in the cooling operation.

High-temperature, high-pressure refrigerant vapor discharged from the compressor 1 flows into the air-conditioning heat exchanger 8 through the refrigerant discharge pipe 16, the high-pressure port 6a of the first four-way valve 6, the second port 6 (L, and the second shut-off valve 12). Here, the refrigerant vapor radiates heat to the indoor air to increase the heating effect, and the refrigerant itself condenses and liquefies.The condensed and liquefied refrigerant is depressurized by the capillary tube 10 associated with the eighth pressure reducing means, and then passed through the third shutoff valve 13. After passing through the heat source side heat exchanger 4
The refrigerant takes heat from the outside air and evaporates.

The evaporated low-pressure refrigerant vapor passes through the first shut-off valve 11, passes through the first port 6C1 (low-pressure port 61) of the first four-way valve 6, flows through the refrigerant suction pipe 16, passes through the accumulator 5, and is sucked into the compressor 1. The same cycle is repeated thereafter.

In this way, during heating operation, the flow of refrigerant is opposite to the flow of refrigerant during cooling operation, and heating is performed by heat radiation in the heating and cooling heat exchanger 8.

Although the hot water heat exchanger 1t is not in use, it is connected to the low pressure side as in the cooling operation, so the refrigerant does not condense and liquefy and accumulate here.

(4) Hot water supply cooling operation In the summer, when hot water supply and cooling are performed at the same time, the first shutoff valve 1
1 is in the closed state, and the second cutoff valve 12, the eighth cutoff valve 18, and the fourth cutoff valve 14 are in the open state.

The first four-way valve 6 allows the refrigerant to flow from the air-conditioning heat exchanger 8 to the refrigerant suction pipe 16 of the compressor l, and the second four-way valve 7Vi allows the refrigerant to flow from the refrigerant discharge pipe 15 of the compressor 1 to the hot water heat exchanger. Refrigerant is now flowing to 2.

The high-temperature, high-pressure refrigerant vapor discharged from the compressor 1 passes through the refrigerant discharge pipe 15, the high-pressure port 7a of the second four-way valve 7, and the first port 7C to the hot water supply heat exchanger 1! ! Flows into vessel 2. Here, the refrigerant vapor radiates heat to the supplied hot water to supply hot water to the section 7, and the refrigerant itself is condensed and liquefied. The condensed and liquefied refrigerant is depressurized by the electronic expansion valve 8, passes through the fourth shut-off valve, and then flows into the air-conditioning heat exchanger 8, where the refrigerant takes heat from the indoor air, increases the cooling effect, and cools itself. evaporates. The evaporated low-pressure refrigerant vapor passes through the second shutoff valve 12 and the second shutoff valve 6 of the first four-way valve 6.
Refrigerant suction fl via port 6a and low pressure port 61:l
flows through the Akicomulator 6 and is sucked into the compressor 1,
The same cycle is repeated thereafter.

The heat source side heat exchanger 4, which is not in use during this operation, has one end of its refrigerant inlet and outlet connected to the piping after the pressure has been reduced by the electronic expansion valve 8, so that the refrigerant does not flow into the heat source side heat exchanger 4. It does not condense and accumulate.

(5) Hot water supply heating operation In winter, when hot water supply and heating are performed at the same time, the fourth shutoff valve 1
The first four-way valve 6, in which the first shutoff valve 11, the second shutoff valve 12, and the eighth shutoff valve 18 are in the open state, connects the refrigerant discharge pipe 15 of the compressor 1 to the air conditioning heat exchanger 8. , the refrigerant flows from the heat source side heat exchanger 4 to the refrigerant suction pipe 16 of the compressor 1, and the second four-way valve 13'
The refrigerant is now flowing from the refrigerant discharge pipe 16 of the compressor 1 to the hot water heat exchanger 2.

The high-temperature Hiita refrigerant vapor discharged from the compressor 1 is partially transferred from the refrigerant discharge [15 to the high-pressure port 61L% of the first four-way valve 6] to the second port 6 (1%) to the air-conditioning heat exchanger 8 via the second shut-off valve 12. A part of the water flows into the hot water heat exchanger 2 via the high pressure port 7& of the second four-way valve 7 and the first port 7C.

The refrigerant vapor radiates heat to indoor air in the air-conditioning heat exchanger 8 to produce a heating effect, and the hot water heat exchanger 2 radiates heat to hot water to produce a hot water supply effect t6, and the refrigerant itself condenses and liquefies.

The refrigerant condensed and liquefied in the hot water heat exchanger 2 is depressurized by the electronic expansion valve 8, and the refrigerant condensed and liquefied in the air conditioning heat exchanger 3 is transferred to the eighth
After being depressurized by the capillary tube 10 related to the field reduction means and merging, passing through the eighth shutoff valve 18, the heat source side heat exchanger 4
Here, it absorbs heat from the air and evaporates. The low-temperature refrigerant vapor passed through the first shut-off valve 11, passed through the first port 60% low pressure port 6b of the first four-way valve 6, and then flowed through the refrigerant suction pipe 16 and passed through the accumulator 5 to the υ king compression machine. 1, and the same cycle is repeated.
.

In this operation, the heat exchanger that becomes unused is the heat exchanger 4 (heat source is air) when the outside air temperature drops during the defrosting operation, hot water heating, and hot water heating operation. Frost may form on the surface. Frost will reduce the capacity, so it is necessary to defrost at appropriate intervals.

In the case of defrosting operation, the first shutoff valve 11 and the fourth shutoff valve 14
Then, the electronic expansion valve 8 is opened, and the second shutoff valve 12 and the eighth shutoff valve 18 are closed.

The first four-way valve 6ti, the state where the refrigerant is not flowing from the refrigerant discharge pipe 15 of the compressor 1 to the heat source side heat exchanger 4, and from the air conditioning heat exchanger 8 to the refrigerant suction pipe 16 of the compressor 1, and the 2 four-way valve? Vi, the refrigerant from the hot water supply heat exchanger 2 to the refrigerant suction pipe 16 of the compressor 1 becomes redundant.

The high temperature and high pressure refrigerant vapor discharged from the compressor 1 flows into the heat source side heat exchanger 4 through the refrigerant discharge pipe 15, the high pressure port 6a1 of the first four-way valve 6, the first port 6C1, and the first shutoff valve 11t. Here, the high-temperature, high-pressure refrigerant vapor melts frost and has a defrosting effect, and the refrigerant itself condenses and liquefies.

The liquefied refrigerant is depressurized by the capillary tube 9 and flows into the hot water heat exchanger 2, where it absorbs heat from the hot water and evaporates itself. The evaporated low-pressure refrigerant vapor is
The refrigerant flows through the refrigerant suction pipe 16 through the first port (70% low king port 71) of the second four-way valve 7, passes through the accumulator 5, is sucked into the compressor 1, and the same cycle is repeated thereafter.

At this time, the heating and cooling heat exchanger 8, which is in an unused state, does not communicate with the high pressure side because the second shutoff valve 12 is in a closed state.
It communicates with the low pressure side, which is depressurized by the capacitor tube 9, via the fourth shutoff valve. Therefore, the refrigerant does not condense and liquefy and accumulate in the heating and cooling heat exchanger 8.

In the defrosting operation described above, the hot water heat exchanger 2 is used as the defrosting heat source heat exchanger, but the air conditioning/heating heat exchanger 8'ft may also be used as the defrosting heat source heat exchanger.

In this case, the second shutoff valve 12 and the eighth shutoff valve 181 are opened, and the electronic expansion valve 8 and the fourth shutoff valve 14 are closed.

As explained earlier, the defrosting effect is achieved in the heat source side heat exchanger 4, and the condensed and liquefied refrigerant is depressurized by the capillary tube 9 and flows into the air conditioning heat exchanger 8, where it removes heat from the indoor air. , the refrigerant itself evaporates. The evaporated low-pressure refrigerant vapor passes through the second shutoff valve 12 and the second shutoff valve 6 of the first four-way valve 6.
Port 6d.

The refrigerant flows through the refrigerant suction pipe 16 through the low-pressure port 61), passes through the accumulator 5, and is sucked into the compressor 1.

The hot water supply heat exchanger 2, which is not in use at this time, communicates with the low pressure side via the second four-way valve 7, so that the refrigerant does not condense and liquefy and accumulate.

As described above, the air-conditioning/heating/water heating apparatus of the embodiment shown in FIG. 1 is capable of each operation of hot water supply, cooling, heating, hot water supply/cooling, hot water supply/heating, and defrosting.

In each of these operations, if there is a heat exchanger that is not in use, the refrigeration cycle is configured so that that heat exchanger is connected to the low pressure side, and in each operation, each heat exchanger that is not in use is In addition, the refrigerant does not condense and liquefy and accumulate. That is,
The refrigerant in the heat exchanger when not in use becomes gaseous by passing to the low-pressure side, and the amount thereof is much smaller than that in the liquid state.

Therefore, there is no shortage of refrigerant per operation in each operation, and performance deterioration in each operation can be prevented.

Next, another embodiment of the present invention will be described with reference to FIG.

FIG. 2 is a system diagram of a refrigeration cycle of an air-conditioning, heating, and hot-water supply system according to another embodiment of the present invention. In the figure, the same reference numerals as in FIG. 1 indicate parts equivalent to those in the above-described embodiment.

17Fi in Figure 2, 8Fi in the example of Figure 1 above.
The reverse valve 18, which replaces the shut-off valve 18, is a check valve which replaces the fourth shut-off valve 14 in the example shown in FIG. be.

The refrigeration cycle shown in FIG. 2 is basically the same as the refrigeration cycle shown in FIG. 1 above, so a detailed explanation thereof will be omitted.

In FIG. 2, both 17 and 18 are shown as check valves, but it is also possible to use either one of 5 as a check valve and the others as shutoff valves.

In addition, in each spinning example, during cooling operation, the eighth
A capillary tube 10 related to king reduction means may also be used. In this case, the eighth shutoff valve 18 is in the open state, and the fourth shutoff valve 14 is in the open state.
f Closed state.

Further, during the heating operation, the capillary tube 9 related to the second field reduction means may be used. In this case, the eighth shutoff valve 18
is in a closed state, and the fourth shutoff valve 14 is in an open state. According to each of these embodiments, effects equivalent to those of the embodiment shown in FIG. 1 can be expected.

Furthermore, as a second flow path switching valve replacing the second four-way valve °7, a refrigerant discharge pipe 15, a hot water supply heat exchanger 2, a refrigerant suction pipe 16
It goes without saying that a three-way valve may be used which allows the water to flow through the hot water and the hot water heat exchanger 2, and which can switch between these flow states.

〔Effect of the invention〕

As described above, according to the present invention, the heat exchanger becomes unused during each operation of cooling, heating, hot water supply, simultaneous operation of cooling and hot water supply, heating and hot water supply, and even defrosting operation. It is possible to provide a heat pump type air-conditioning/heating/hot-water supply device that prevents liquid refrigerant from accumulating in the container and therefore allows each operation to be performed efficiently.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a refrigeration cycle of an air-conditioning, heating, and hot-water supply apparatus according to an embodiment of the present invention, and FIG. 2 is a system diagram of a refrigeration cycle of an air-conditioning, heating, and water-heating system according to another embodiment of the present invention. 1... Compressor 2... Hot water heat exchanger 8... Air conditioning heat exchanger 4... Heat source side heat exchanger 5... Accumulator 6... First four-way valve 6a... High pressure port 6b...Low pressure port 6C...1st port 6(
L...Second port 7...Second four-way valve 7a...
High pressure port 7b...Low pressure port 8...Electronic expansion valve 9.10...Middle tip tube 11...
First shut-off valve 12... Second shut-off valve 18... Eighth shut-off valve 14... Fourth shut-off valve 16... Refrigerant discharge pipe 1
6... Refrigerant suction pipe 17.18... Check valve

Claims (1)

[Claims] 1. A compressor, a hot water supply heat exchanger, an air conditioning heat exchanger, a heat source side heat exchanger, an accumulator, a first flow path switching valve capable of switching a refrigerant flow path in at least four directions, and a refrigerant flow path in at least three directions. A second flow path switching valve capable of switching the flow path, a first shutoff valve, a second shutoff valve, an eighth shutoff valve, a fourth shutoff valve, a first pressure reducing means, a second pressure reducing means, a third pressure reducing means, and these The refrigerant hot water supply device constitutes a refrigeration cycle with refrigerant piping connected to the refrigerant water supply device, wherein the high pressure port of the first flow path switching valve, which is always at high pressure, is connected to the refrigerant discharge pipe of the compressor, and the low pressure, which is always at low pressure, is connected to the refrigerant discharge pipe of the compressor. A port is connected to the refrigerant suction pipe of the compressor through the accumulator, a first port is connected to one end of the heat source side heat exchanger through the first shutoff valve, and a second port is connected to the refrigerant suction pipe of the compressor through the second shutoff valve. The high pressure port of the second flow path switching valve, which is always at high pressure, is connected to the compressor and the first flow path switching valve in the middle of the piping. , a low pressure port that is always at low pressure is placed in the middle of the piping connecting the first flow path switching valve and the accumulator;
The remaining one part is connected to one end of the hot water heat exchanger by piping, and the other end of the hot water heat exchanger is arranged in parallel with the first pressure reducing means at the other end of the heat source side heat exchanger. The second pressure reducing means and the third shutoff valve are connected via piping provided in series, and
The third pressure reduction means and the fourth 1. An air-conditioning, heating, and water-heating device characterized in that it is connected via piping equipped with a shut-off valve to form a refrigeration cycle. 2. The air-conditioning/heating and hot water supply apparatus according to claim 1, wherein both or either of the third shut-off valve and the fourth shut-off valve is a check valve.