JPH01291077A - Air conditioning device - Google Patents

Abstract

PURPOSE:To prevent a phenomenon of liquid returning into a compressor from being attained by a method wherein a part of gas coolant of high temperature and high pressure from the compressor exchanges heat with a suction side pipe through a suction heat exchanger. CONSTITUTION:Gas coolant of high temperature and high pressure from a compressor 1 exchanges heat with a suction pipe 1a and a pipe between a first metering device 4 and a second metering device 5 is provided with a bypassing circuit 10. First pressure reducing device 4a and second pressure reducing device 5a are provided with a smaller fourth bypassing circuit 14 than a discharging pipe bypassing and connected from a second bypassing circuit 4c and a third bypassing circuit 5c having bypassed check valves 4b and 5b and a discharging pipe 1b of the compressor to the pipe between the first metering device and the second metering device through a three-way changing- over valve 13. With this arrangement, a blowing of cold air into a room during a defrosting operation in case of a heating operation is prevented, a four-way changing- over valve is operated while keeping its heating side to reduce a low pressure and then a capability of the compressor is increased. In addition, gas coolant of high temperature and high pressure from the compressor exchanges heat with an absorbing pipe and then a liquid return to the compressor is also prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in an air conditioner that performs heating and cooling operations using a refrigeration cycle circuit.

[Conventional technology]

Conventionally, this type of air-conditioning bag has been constructed as schematically shown in FIG. To explain this simply, the middle mark 4 in the figure
') l is the pressure ma, 2 is the four-way switching valve, 3 is the outdoor heat exchanger, 4.5 is the first and second throttle devices that function as expansion mechanisms during cooling operation and heating operation, respectively, and 6 is the indoor The inner heat exchanger 7 is an accumulator, and a refrigeration cycle circuit is constructed by sequentially connecting these with refrigerant piping. In addition, 8.9 is the indoor side and outdoor side blower that blows air to the indoor side and outdoor side heat exchanger 6゜3, respectively, and 4.
a, 4b is a ml vacuum bag g! that constitutes the first squeezing device g14. 1 (capillary tube) and a first reverse IE valve 5a, 5b provided in a circuit that bypasses this; A second reverse 1F valve is provided in the bypassing circuit.

In this air conditioner with such a configuration, during the cooling r1 operation (the flow of the refrigerant is shown by the thick solid line arrow in the figure), the compression is 4I! The high-temperature, high-pressure gas refrigerant discharged from 1 passes through the four-way switching valve 2, exchanges heat with outdoor air blown by the outdoor air blower a9 in the outdoor heat exchanger 3, and the gas refrigerant is condensed and liquefied. Then, it passes through the first check valve 4b in the bypass circuit on the side of the first throttle device 2!4, and is introduced into the second pressure reducing device 5a forming the second throttle device 5, where the pressure is reduced. It becomes a low temperature, low pressure liquid refrigerant. After that, this liquid refrigerant enters the indoor heat exchanger 6 and exchanges heat with the indoor air blown by the indoor blower 8 to cool the indoor air. 2. A refrigeration cycle during cooling is constructed in which the refrigerant passes through the accumulator 7 and returns to the compressor 1. Thereafter, the refrigerant is circulated through the above-mentioned refrigeration cycle path while repeating liquefaction and vaporization.

On the other hand, during warm J77 operation (the flow of the refrigerant is shown by the thin solid line arrow in the figure), the high temperature and high pressure gas refrigerant discharged from the pressure mal passes through the four-way switching valve 2 which is switched to the warm side. Enters the indoor heat exchanger 6.

The indoor air is heated by exchanging heat with the indoor air blown by the indoor blower 8, and the regas refrigerant is condensed and liquefied. And, this liquid refrigerant is passed through the second diaphragm! ! The first decompression bag 214 that passes through the second check valve 5b in the circuit that bypasses i5 and constitutes the first squeezing device 4
The refrigerant is led to a vacuum and becomes a low-temperature, low-pressure liquid refrigerant. After that, the liquid refrigerant enters the outdoor heat exchanger 3 and the outdoor fan 9.
The liquid refrigerant evaporates into gas, passes through the four-way switching valve 2 and the accumulator 7, and returns to the pressure of 1itai. A refrigeration cycle is constructed.

Also, if you continue to use this type of heating operation,
For example, when the outdoor air temperature is low, frost forms on the outdoor heat exchanger 3. When such frost builds up, the heat exchange efficiency deteriorates, and the amount of heat borrowed from outdoor air decreases, resulting in a significant decrease in the heating capacity of the air conditioner. Therefore, in such a case, it is necessary to defrost the vehicle.

During such defrost operation (the flow of refrigerant is indicated by the dashed arrow in the figure), the high temperature and high pressure gas refrigerant discharged from the pressure 11i1ml is transferred from the four-way switching valve switched from the heating side to the cooling side. 2 and enters the outdoor heat exchanger 3. Here, the outdoor side blower 9 is stopped. Then, the frost that has formed on the surface of the outdoor heat exchanger 3 is dissolved by a high-temperature gas refrigerant, and the refrigerant is condensed and liquefied to bypass the first throttle device 4. As a result, the pressure is reduced by the second pressure reducing device 5a constituting the second expansion device 5 to become a low temperature, low pressure liquid refrigerant, which enters the indoor heat exchanger 6 and is then compressed through the four-way switching valve 2 and the accumulator 7. Ia
The refrigeration cycle operation was performed by returning to 1.

[5 that the invention attempts to solve! Title] By the way, the warmth mentioned above! Some problems occur when low-temperature, low-pressure liquid refrigerant is introduced into the indoor heat exchanger 6 during the defrost operation during the M operation. That is, the indoor air blower a8 disposed opposite to the indoor heat exchanger 6 normally performs a light air operation or is stopped during the defrost operation. And, for example, fine x
When the i-turn is performed, the low-temperature, low-pressure liquid refrigerant and indoor air exchange heat, cool the indoor air, and the liquid refrigerant evaporates into gas, passes through the four-way switching valve 2 and the accumulator 7, and enters the compressor l. return. Therefore, in such a case, cold air is blown toward the indoor side, causing a problem in that the air conditioning effect is significantly reduced.

Also, when the indoor fan 8 is stopped.

Heat cannot be collected from the low-temperature, low-pressure liquid refrigerant, and the refrigerant enters the accumulator 7 as a liquid and returns to the compressor 1, so the compressor 1 compresses the liquid, sometimes causing compressor trouble.

Furthermore, according to the conventional double-connected device, since the high pressure is low, especially during defrosting, the low pressure also decreases, and the capacity of the compressor 1 cannot be fully demonstrated.

There were drawbacks such as a long defrost time.

Furthermore, since the four-way switching valve 2 is switched to the cooling side during heating operation to perform defrost operation, there is also a problem that heat loss occurs during switching.

The present invention was made in view of the above-mentioned circumstances, and prevents cold air from being blown into the room during defrost operation during heating operation, and also prevents the defrost E rotation while the four-way selector valve is set to the heating side. By increasing the low pressure and increasing the compression function, the system is configured to exchange heat between the high-temperature, high-pressure gas refrigerant from pressure 11!4a and the suction side piping, which also prevents liquid from returning to the compressor. The purpose is to obtain an air conditioner that can

[Means to solve the problem]

The air conditioner according to the present invention has a first bypass circuit that exchanges heat with the suction side piping and bypasses the high temperature, high pressure gas refrigerant from the compressor to the piping side between the first expansion device and the second expansion device. and a first pressure reducing device and fjS2
second and third bypass circuits each having a check valve that bypasses the pressure reducing device, and a three-way switching valve from the discharge side piping of the compressor to the piping side between the first and second throttling devices; A bypass circuit t54 is provided by a pipe having an inner diameter smaller than that of the discharge pipe connected to the discharge pipe, and an auxiliary pressure reducing means is connected from this fourth bypass circuit to the suction pipe of the compressor in a bypass manner. A fifth bypass circuit is selectively provided.

[Effect]

According to the present invention, during the defrost operation during the heating operation, the blower to the indoor side and the indoor heat exchanger is stopped while the four-way switching valve remains in the heating operation state.

In addition, by switching the three-way switching valve and opening the fourth bypass circuit (and selecting the fifth bypass circuit), which has a pipe inner diameter smaller than that of the discharge side pipe, to perform defrost operation, it is possible to This prevents heat loss when switching the switching valve, prevents cold air from blowing into the room, increases the capacity of the compressor, and exchanges heat between the high-temperature, high-pressure gas refrigerant from the compressor and the suction side piping. This can also prevent liquid from returning to the compressor.

〔Example〕

FIG. 1 shows an embodiment of an air conditioner according to the present invention, and in this figure, the same or corresponding parts as those in FIG.

Now, according to the present invention, the compressor l, the four-way switching valve 2, the outdoor heat exchanger "a3", the first throttle device 4, the second throttle device f2
'15, In an air conditioner equipped with a refrigerant circuit in which an indoor heat exchanger 6 and an accumulator 7 are sequentially connected by refrigerant piping, the connection between the accumulator 7 and the compressor l is branched from the discharge side piping of the compressor l. A suction heat exchanger it configured to be able to exchange heat with the suction side piping 1a connecting between
and the auxiliary capillary tube 12 to the piping side between the first and second restricting devices 214.5 in a bypass manner, and the f-th first pressure reducing device '14a. A second bypass circuit 4C provided with a check valve 4b that bypasses it, and a third bypass circuit 5C provided with a check valve 5b that bypasses the second pressure reducing device ¥15a.
and from the inner diameter of the discharge side piping 1b which is connected from the discharge side piping 1b of the compressor 1 via the three-way switching valve 13 to the piping side between the first and FF12 throttling devices 4.5 in a bypass manner. It is also characterized in that a fourth bypass circuit 14 having a narrow pipe inner diameter is provided. In such a configuration, during the defrost operation, the four-way switching valve 2 remains in the heating operation state, and the air blowers a8 and 9 that blow air to the indoor and outdoor heat exchangers 6 and 3 are stopped, and the three-way switching and fp13 Switch to the fourth
The bypass circuit 14 is opened to enable defrost operation.

In the air conditioner with the above configuration, during cooling operation (
The flow of refrigerant (in the direction of the thick solid line arrow in the figure) is at pressure l.
The high-temperature, high-pressure gas refrigerant discharged from the LLI machine 1 passes through the four-way switching valve 2 and is sent to the outdoor side heat exchanger 3 to be sent to the outdoor side air blower 4!19.
The gas refrigerant is condensed and liquefied as well as exchanging heat with the outdoor air blown by the refrigerant. And the first shibori! ! The refrigerant is depressurized by the first depressurization '4Jg4a at step 14, and becomes a low-temperature, low-pressure liquid refrigerant. On the other hand, a part of the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 exchanges heat with the low-pressure refrigerant sucked into the compressor 1 in the suction heat exchanger 11 passing through the first bypass circuit 10, and converts the suction refrigerant into It is heated to completely vaporize, condenses and liquefies itself, and is depressurized by the auxiliary capillary tube 12 to become a low-temperature, low-pressure liquid refrigerant.
It joins the piping between the first and second throttle devices 4.5, enters the third bypass circuit Se1 in the second throttle device 5, enters the indoor heat exchanger 6, and enters the room where air is blown from the indoor fan 8. It also cools indoor air by exchanging heat with the air.

As a result, the liquid refrigerant is evaporated and gasified, passes through the four-way switching valve 2 and the accumulator 7, and returns to a pressure of 16A, thereby forming a refrigeration cycle circuit.

In addition, during heating operation (the flow of refrigerant is in the direction of the arrow indicated by the thin solid line in the figure), the high-temperature, high-pressure gas refrigerant discharged from compression R1 passes through the four-way switching valve 2, which is switched to the heating side, and heats the indoor area. Enter exchanger 6.

The indoor air is heated by exchanging heat with the indoor air blown from the indoor blower 8, and the gas refrigerant is thereby condensed and liquefied. Then, the pressure is reduced by the second pressure reducing device 5a in the second expansion device 5, and the refrigerant becomes a low-temperature, low-pressure liquid refrigerant. On the other hand, a part of the high temperature and high pressure gas refrigerant discharged from the pressure lif machine 1 passes through the first bypass circuit 10,
The refrigerant exchanges heat with the low-pressure refrigerant sucked into the compressor l, heats the suction refrigerant, and completely vaporizes the refrigerant.
It becomes a low-temperature, low-pressure liquid refrigerant, joins the pipe side, passes through the second bypass circuit 4C in the first throttle device 4, enters the outdoor heat exchanger 3, and is combined with the outdoor air blown from the outdoor air blower Ia9. In addition to exchanging heat and collecting heat from the outdoor air to cool the outdoor air, the liquid refrigerant evaporates into gas.
Four-way switching valve2. A refrigeration cycle circuit is constructed in which the air passes through the accumulator 7 and returns to compressed Al.

In addition, during such a heating operation, for example, during a defrost operation that is required when the outdoor air temperature is low and frost forms on the outdoor heat exchanger 3 (refrigerant flow is in the direction of the arrow indicated by the broken line in the figure). In this case, the high temperature and high pressure gas refrigerant discharged from the pressure Ild machine is.

Three-way switching valve 13 switched to the defrost side
through the first and tPj2 throttling devices 4, 5 flll
It flows into the piping side through the fourth bypass circuit 14 connected to the piping side of the pipe.

On the other hand, a part of the high-temperature and high-pressure gas refrigerant discharged from the compressed ml passes through the first bypass circuit 10 and is heat exchanged with the low-pressure refrigerant sucked into the pressure I & machine 1 in the suction heat exchanger 11, The suction refrigerant is heated to completely vaporize it, and it condenses and liquefies itself and is depressurized by the auxiliary capillary tube 12 to become a low-temperature, low-pressure liquid refrigerant, which is mixed with the high-temperature, high-pressure gas refrigerant that has passed through the fourth bypass circuit 14. Ru. These combined gas refrigerants then pass through the second bypass circuit 4C in the first expansion device 4 and enter the outdoor heat exchanger 3. At this time, the outdoor air blower Ia9 is stopped. And the high temperature gas refrigerant is an outdoor heat exchanger! !
! ! The frost that has formed on the surface of the container 3 is melted with a high temperature gas refrigerant,
This refrigerant is condensed and liquefied, passes through the four-way switching valve 2, enters the accumulator trough, and is returned to the compressor 1.

Therefore, during such defrosting, it is possible to enter the four-way defrost mode without switching the four-way switching valve 2 from the heating side to the cooling side. Since the liquid refrigerant does not pass through the indoor heat exchanger 6, the conventional problem of cold air being blown indoors is also solved. Furthermore, since the inner diameter of the piping constituting the fourth bypass circuit 14 is made smaller than that of the discharge side piping tb, pressure loss occurs and the pressure on the high pressure side of the compression fit rises, causing an increase in input. , pressure 1ilIJ! L's power increases and shortening the defrost time becomes a 5f ability. In addition, since the suction heat exchanger 11 is configured to exchange heat with the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 in the suction side piping 1a to the compressor 1, it is possible to prevent liquid from returning to the compression fit. , it becomes possible to prevent compressor troubles.

Here, as shown by 15 in the figure, 'rl!' faces the indoor heat exchanger 6. If you install a heating device.

During defrost operation, the refrigerant flows into this indoor heat exchanger 6.
Because you don't have to go through it, you can go indoors! This has the advantage that the IL device 8 can be operated and the heating operation can be continued even during the defrost m transition.

FIG. 2 shows another embodiment of the air conditioner according to the present invention, and in this embodiment, the first and 0'S2 throttles are A fourth pipe is connected to the piping between equipment 4 and 5 by bypass.
A third reverse +L valve 18 is provided in the bypass circuit 14 of
The fifth bypass circuit 16 is provided with an auxiliary capillary tube 17 as an auxiliary pressure reducing means connected to the a side in a bypass manner.

According to such a configuration, during cold mW operation and heating operation, the operating state is similar to that of the above-described embodiment, but during defrost operation, the following operating state is obtained. That is, during this defrost operation, the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the three-way switching valve 13 to the fourth
After passing through the third reverse valve 18 through the bypass circuit 14, it flows into the piping between the throttling devices 4 and 5 at 0'S1 and t52. Further, a part of the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 heats and vaporizes the low-pressure refrigerant on the suction side of the compressor 1 through the first bypass circuit 10, and also condenses and liquefies itself. The pressure is reduced to become a low-temperature, low-pressure liquid refrigerant, which is mixed with the high-temperature, high-pressure gas refrigerant from the fourth bypass circuit 14 side, and is sent to the outdoor heat exchanger 3 side through the second bypass circuit 4C, and its surface The frost that has formed on the refrigerator is melted, and the refrigerant is condensed and liquefied through the four-way switching valve 2 and the accumulator 7 to the compressor 1.
Inhaled to the side. In addition, the suction side piping la of this compressor l
The refrigerant inside is vaporized by the high-temperature, high-pressure gas refrigerant flowing through the first bypass circuit 10 by the suction heat exchanger 11, so that the phenomenon of liquid returning to the compressor 1 can be prevented.

According to this embodiment, during such a defrost operation, a part of the high-temperature, high-pressure gas refrigerant passing through the fourth bypass circuit 14 is branched to the fifth bypass circuit 16 and transferred to the auxiliary capillary tube 17. Since the amount of Ii is controlled by Ii, it is clarified into the low pressure side (suction side piping 1a) of the compressor l, so the low pressure is increased, the capacity of the pressure IIdJal is increased, and the defrost time can be shortened. It becomes possible to play.

Note that the present invention is not limited to the structure of the embodiment described above, and the shape, structure, etc. of each part of the air conditioner may be modified and changed as necessary.

〔Effect of the invention〕

As explained above, according to the air conditioner according to the present invention, a part of the high temperature and high pressure gas refrigerant from the pressure llIi machine is configured to exchange heat with the suction side piping via the suction heat exchanger. , it is possible to prevent the phenomenon of liquid returning to the compressor, and the three-way switching valve can be switched to ν while the four-way switching valve is in heating operation.
It is possible to perform defrost operation by switching between the four-way switching valve, which prevents heat loss, etc. caused by switching the four-way switching valve as in the past.
Moreover, it has a very modest effect, such as making it possible to eliminate the conventional problem of blowing cold air toward the indoor side. Furthermore, according to the present invention, during defrost operation, the gas refrigerant on the discharge side from the compressor passes through the bypass circuit having a diameter smaller than that on the discharge side piping, so that the high pressure increases, thereby improving the compression a pressure. This has advantages such as shortening the defrost time.

Further, according to the present invention, a part of the high temperature and high pressure discharged gas can be bypassed to the low pressure side of the compressor, so the low pressure can be increased, and the capacity of the pressure Ii1 machine can be fully demonstrated,
Another advantage is that the defrost time can be further shortened.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a refrigeration cycle circuit showing an embodiment of an air conditioner according to the present invention. 7Sz is a schematic configuration diagram of a refrigeration cycle circuit showing another embodiment of the present invention, and FIG. 3 is a schematic configuration diagram showing a conventional example. l...Compressor, la...Suction side piping, 1b...
...Discharge side piping, 2...Four-way switching valve, 3...Outdoor heat exchanger, 4.5...First and second throttling device, 4a, 5a...No. 1 and 2nd pressure reducing device (capillary tube), 4b, 5b...-Check valve, 4c
, 5c...first and second bypass circuits, 6.
...Indoor heat exchanger, 7...Accumulator, 8
．． 9... Indoor and outdoor blowers, 10...
First bypass circuit, 11... Suction heat exchanger, 12... Auxiliary capillary tube, 13...
Three-way 9J exchange valve, 14...4th bypass circuit, 15
...Electric heater, 16...Fifth bypass circuit, 1
7... Auxiliary capillary tube (auxiliary pressure reducing means),
18...Third reverse I valve. Agent Masuo Oiwa Figure 2 1 Shi: Zego 2 I Rule -: j + Rumor - i Tatoi 1 Figure 3

Claims (2)

[Claims] (1) A refrigerant circuit formed by sequentially connecting a compressor, a four-way switching valve, an outdoor heat exchanger, a first expansion device, a second expansion device, an indoor heat exchanger, and an accumulator through refrigerant piping; It is configured to be able to exchange heat with a suction side pipe that is branched from the discharge side pipe of the compressor and connects the accumulator and the compressor, and is bypassed to the pipe side between the first and second throttle devices. a first bypass circuit connected to the first bypass circuit, and a second bypass circuit having a check valve that bypasses a first pressure reducing device constituting the first throttle device; and a third bypass circuit having a check valve that bypasses the second pressure reducing device, and piping between the first and second throttle devices from the discharge side piping of the compressor via a three-way switching valve. A fourth bypass circuit having a pipe inner diameter smaller than the inner diameter of the discharge side pipe connected to the side in a bypass manner is provided, and during defrost operation, the four-way switching valve is kept in the heating operation state and the fourth bypass circuit is connected to the indoor side. and an air conditioner configured to stop the blower blowing air to the outdoor heat exchanger, switch the three-way switching valve, open the fourth bypass circuit, and perform defrost operation. (2) In the air conditioner according to claim 1, a fifth bypass circuit having an auxiliary pressure reducing means connected from the fourth bypass circuit to the suction side piping side of the compressor in a bypass manner is provided, and during defrost operation, This fifth bypass circuit,
An air conditioner configured to open together with the fourth bypass circuit.