JP2001021229A - Refrigerant circulation type heat transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the refrigerant circuit of a refrigerant circulation type heat transfer device with a bypass passage to prevent the excessive increase of a pressure on the high pressure side and regulate a balance between radiation capacity and heat absorption capacity and to prevent the generation of noise when a refrigerant passes through the bypass passage. SOLUTION: A refrigerant circulation type heat transfer device is formed such that a refrigerant circuit 30 is provided with a bypass passage 36 to intercouple a high pressure refrigerant circuit and a low pressure refrigerant circuit in parallel to an electronic expansion valve 34 and an opening-regulatable control valve 37 having a function as a pressure reducing valve is situated in the middle of the bypass passage 36. Further, a heat-exchanger 38 is provided to effect heat-exchange between the spots situated upper stream and downstream from the control valve 37. This constitution performs radiation and condensation of a high pressure refrigerant flowing in the bypass passage 36 and imparts its heat to a refrigerant on the low pressure side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant circulation type heat transfer apparatus having a refrigerant circuit for circulating refrigerant discharged from a compressor through a condenser, a throttle, and an evaporator so as to return to the compressor. .

[0002]

2. Description of the Related Art Conventionally, in such a refrigerant circulation type heat transfer device, a high pressure refrigerant circuit (a circuit from a compressor to a throttle through a condenser) and a low pressure refrigerant circuit (a throttle to an evaporator are bypassed). By providing a bypass passage connecting to the compressor and a circuit leading to the compressor), and by providing a pressure-reducing valve capable of adjusting the flow rate in this bypass passage, when the pressure in the high-pressure refrigerant circuit becomes abnormally high for some reason, In a case where the load is rapidly reduced, a part of the high-pressure refrigerant is bypassed from the high-pressure refrigerant circuit through the bypass passage to the low-pressure side through the bypass passage.

For example, Japanese Patent Application Laid-Open No. 10-38410 discloses a high pressure refrigerant circuit between a compressor and a condenser, and a low pressure refrigerant circuit between a expansion valve and an evaporator. Are connected by a bypass passage, and an opening / closing control valve is provided in the bypass passage so that the opening / closing control valve is opened when the pressure of the high-pressure refrigerant circuit detected by the pressure sensor is high.

[0004]

In this type of conventional apparatus, when the bypass passage is opened to bypass the refrigerant from the high-pressure side to the low-pressure side, the refrigerant flowing from the high-pressure refrigerant circuit into the bypass path has a high temperature and a high pressure. Since it is gaseous and has a large volume and a high flow rate, a large airflow noise is likely to be generated when passing through the pressure reducing valve including the opening / closing control valve and the like.

[0005] In view of such circumstances, the present invention provides a refrigerant circulating system capable of preventing the generation of noise when the refrigerant passes through the bypass passage, while enabling load control and the like to be effectively performed by the bypass passage. It is an object to provide a heat transfer device.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a refrigerant circulation type heat transfer device having a refrigerant circuit for circulating refrigerant discharged from a compressor through a condenser, a throttle, and an evaporator so as to return to the compressor. A bypass passage connecting the high-pressure refrigerant circuit from the compressor to the throttle via the condenser and the low-pressure refrigerant circuit from the throttle to the compressor via the evaporator in parallel with the throttle, and an open passage provided in the middle of the bypass passage. And a heat exchanger for performing heat exchange between an upstream portion and a downstream portion of the pressure reducing valve in the bypass passage.

[0007] According to this device, when the refrigerant flows through the bypass passage while the pressure reducing valve is controlled in accordance with the operation state or the like, the gaseous high-pressure refrigerant flowing from the high-pressure refrigerant circuit into the bypass passage is removed. In the heat exchanger, heat is released and condensed to change to a liquid or gas-liquid two-phase state, thereby reducing the volume and the flow velocity, so that almost no sound is generated when passing through the pressure reducing valve.

In the present invention, the bypass passage is
For example, it connects the upstream part of the condenser in the high-pressure refrigerant circuit to the upstream part of the evaporator in the low-pressure refrigerant circuit.

[0009] In this case, there is an imbalance between the heat radiation capacity and the heat absorption capacity such that the heat absorption capacity of the evaporator is relatively lower than the heat radiation capacity of the condenser depending on the outside air temperature and operating conditions. When things go wrong,
By opening the bypass passage, the balance between the heat dissipation ability and the heat absorption ability is appropriately adjusted. Then, an effect of suppressing the generation of noise is obtained while such an adjusting function is exhibited.

The bypass passage may connect an upstream portion of the condenser in the high-pressure refrigerant circuit and a downstream portion of the evaporator in the low-pressure refrigerant circuit.

In this way, for example, when the required cooling capacity or required heating capacity in the air conditioner suddenly decreases,
Or, when the required refrigerating capacity in the refrigerating device suddenly decreases, or when the pressure in the high-pressure refrigerant circuit excessively increases for some reason, the load is reduced by opening the bypass passage, and the demand is reduced. Accordingly, a reduction in the cooling capacity or the like is promoted or a pressure increase is suppressed. Then, an effect of suppressing the generation of noise is obtained while such an adjusting function is exhibited.

A second evaporator is provided between the evaporator and the compressor in the low-pressure refrigerant circuit, and the bypass passage is provided in a portion between an outlet of the condenser and an inlet of the throttle in the high-pressure refrigerant circuit. The position near the outlet of the condenser may be connected to the position between the evaporator and the second evaporator in the low-pressure refrigerant circuit.

[0013] In this case, when an imbalance occurs between the heat dissipation capacity of the condenser and the heat absorption capacity of the evaporator, the bypass passage is opened to balance the heat dissipation capacity and the heat absorption capacity. Is properly adjusted. And while such an adjustment function is exhibited,
The effect of suppressing the generation of noise can be obtained.

[0014]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an air conditioner as an example of a refrigerant circulation type heat transfer device of the present invention.
It is composed of an outdoor unit 1a and a plurality of indoor units 1b. This air conditioner includes a water-cooled gas engine 2
(Hereinafter, abbreviated as engine 2), a refrigerant circuit 30 including a compressor 20 driven by the engine 2, and a cooling water circuit 90 for cooling the engine 2 are provided. 30 is disposed over the outdoor unit 1a and each indoor unit 1b, and the compressor 20, the engine 2, the cooling water circuit 90, etc. in the refrigerant circuit 30 are disposed in the outdoor unit 1a.

An intake pipe 3 is connected to the engine 2.
The intake pipe 3 is provided with an air cleaner 4, a mixer 5, a throttle valve 6, and the like. In the mixer 5,
A fuel supply pipe 7 for guiding fuel from a fuel gas supply source (not shown) is connected, and a flow control valve 8, electromagnetic valves 9, 10 and the like are interposed in the fuel supply pipe 7. The fuel gas and the air are mixed by the mixer 5, and the amount of the air-fuel mixture is controlled by the throttle valve 6, whereby the output of the engine 2 is controlled.

An exhaust pipe 11 extends from the engine 2, and an exhaust gas heat exchanger 12 is interposed in the exhaust pipe 11. Further, an oil tank 14 is connected to an oil pan of the engine 2 via an oil supply pipe 13.
The oil supply pipe 13 is provided with a solenoid valve 15 for adjusting the oil supply amount. Reference numeral 16 denotes a heater for adjusting the oil temperature in the oil pan of the engine 2. Reference numeral 17 denotes an exhaust gas temperature sensor for detecting the exhaust gas temperature.

The compressor 20 is a multi-type compressor having two unit compressors 20a and 20b in the illustrated example, and each of the unit compressors 20a and 20b is an electromagnetic clutch 2a.
It is connected to the output shaft 22 of the engine 2 via 1a and 21b. Reference numerals 24 and 25 are compressor temperature sensors for detecting the compressor temperature.

The refrigerant circuit 30 passes the refrigerant discharged from the compressor 20 through a condenser, a throttle, and an evaporator.
To form a closed circuit for circulating so as to return to. In the present embodiment, a four-way valve 31 for switching the refrigerant circulation path according to the time of cooling and the time of heating is provided, and the outdoor heat exchanger 32 that forms one of the condenser and the evaporator, and the other that forms the other An indoor heat exchanger 33 and an electronic expansion valve 34 constituting a throttle. The four-way valve 31 and the outdoor heat exchanger 32 are provided in the outdoor unit side circuit of the refrigerant circuit 30, while the indoor heat exchanger 33 and the electronic expansion valve 34 are provided in a plurality of indoor unit side circuits, respectively. Have been.

Further, in parallel with the electronic expansion valve 34, a high-pressure refrigerant circuit from the compressor through the condenser to the electronic expansion valve (throttle) and a low-pressure refrigerant from the electronic expansion valve (throttle) through the evaporator to the compressor. A bypass passage 36 is provided for connecting to a circuit. The bypass passage 36 is provided with a control valve 37 constituting a pressure-reducing valve whose opening can be adjusted.
7 is provided with a heat exchanger 38 for performing heat exchange between the upstream part and the downstream part.

More specifically, the refrigerant circuit 30 will be described. Between the compressor 20 and the four-way valve 31, a discharge line 41 connecting the discharge port of the compressor 20 and the first port 31a of the four-way valve 31 is provided. , The second port 31b of the four-way valve 31 and the compressor 20
And a suction-side line 42 for connecting the suction port with the suction port. The discharge side line 41 is provided with an oil separator 43 for separating oil from the high-pressure refrigerant, and the separated oil is guided to a downstream portion of the suction side line 42 via a strainer 44 and a capillary tube 45. I have.

An accumulator 46 is provided on the suction side line 42. The suction-side line 42 includes an upstream line 42a connecting the four-way valve 31 and the inlet of the accumulator 46, a line 42b connected to the outlet of the gas-phase refrigerant of the accumulator 46, and a capillary 47 connected to the line 42b. A downstream line 42c connected via a U-shaped line 42d, the downstream line 42c being connected to a suction port of the compressor 20, and a passage 42e branched from the downstream line 42c being connected to the capillary 4
8, connected to the compressor 20 via a valve 49 and a strainer 50.

Then, the gas-phase refrigerant and the liquid-phase refrigerant are separated by the accumulator 46, and the gas-phase refrigerant is supplied to the line 42b,
The air is sucked into the compressor 20 via the capillary tube 47 and the line 42c. Further, the lower end of the accumulator 46 is connected to the line 42d via a passage having the strainer 51 and the control valve 52 so that the lubricating oil in the accumulator 46 can be led out if necessary.

A predetermined high level position and a predetermined low level position (for example, the lowest position) of the accumulator 46 are connected to the line 42d through the liquid level detecting passages 53 and 54,
Strainers 55, 56 are provided in the respective passages 53, 54, respectively.
And capillaries 57, 58 are provided, and each passage 5
Heaters 59, 60 and temperature sensor 6 for 3, 54
1, 62 are provided. The liquid level in the accumulator, that is, the storage amount of the liquid-phase refrigerant, is detected by detecting a temperature change in the passage when the liquid-phase refrigerant is led out to the paths 53 and 54.

The accumulator 46 is provided with a heater 63. The four-way valve 31 and the accumulator 46
A heat exchanger 64 for heating the refrigerant with engine waste heat is provided in the line 42a between the heat exchanger 64 and the heat exchanger 64.

An outdoor heat exchanger 32 is connected to the third port 31c of the four-way valve 31 via a line 65, and a line 66 is connected to the outdoor heat exchanger 32. This line 66 passes through the heat exchanger 38 and reaches the joint 69 via the strainer 67 and the manual valve 68. The line 70 is connected to the fourth port 31d of the four-way valve 31,
This line 70 reaches a joint 73 via a strainer 71 and a manual valve 72.

On the other hand, in each indoor unit 1b, an indoor heat exchanger 33 and an electronic expansion valve 34 are provided in a state of being connected in series.
The indoor heat exchanger 33 is connected to a line 74 connected to the external unit 0 via a joint 73, and the electronic expansion valve 34 is connected to a line 75 connected to a line 66 of the outdoor unit side circuit via a joint 69. ing.

Further, an electronic expansion valve 34 is provided in the refrigerant circuit 30.
In this embodiment, a bypass passage 36 that connects the high-pressure refrigerant circuit and the low-pressure refrigerant circuit is provided in parallel to the middle of a line 70 that communicates with the fourth port 31d of the four-way valve 31 in the outdoor unit-side circuit. The bypass passage 36 is connected to the middle of a line 66 connected to the
Are formed. That is, the bypass passage 36 is formed so as to connect the upstream part of the condenser (the indoor heat exchanger 33) in the high-pressure refrigerant circuit and the upstream part of the evaporator (the outdoor heat exchanger 32) in the low-pressure refrigerant circuit during heating.

In the middle of the bypass passage 36, a control valve 37 is provided.
The control valve 37 has the same structure as the electronic expansion valve, expands and reduces the pressure of the refrigerant passing through the valve 37, and allows the refrigerant to flow continuously from the fully closed state. The amount can be adjusted. In this embodiment, a portion of the bypass passage 36 between the connection to the line 70 and the control valve 37 is disposed so as to pass through the heat exchanger 38, so that, as described in detail later, during heating, The heat exchange is performed between the high-pressure refrigerant in the bypass passage 36 upstream of the control valve 37 and the low-pressure refrigerant in the line 66 downstream of the control valve 37.

Further, a strainer 76 is provided in the bypass passage 36, and a refrigerant temperature sensor 77 is provided. The heat exchanger 3 in the line 66
Refrigerant temperature sensors 78 and 79 are also provided on the upstream and downstream sides of 8.

In addition, various detection elements provided for the refrigerant circuit 30 include a high pressure side pressure sensor 81, a low pressure side pressure sensor 82, a compressor discharge side refrigerant temperature sensor 83, a compressor suction side refrigerant temperature sensor 84, An outside air temperature sensor 85 and the like are provided on the outdoor unit 1a side, and refrigerant temperature sensors 86 and 87 on the upstream and downstream sides of the electronic expansion valve 34,
An indoor temperature sensor 88 and the like are provided on the indoor unit 1b side.

The cooling water circuit 90 includes a main water pump 92, an exhaust gas heat exchanger 12, an engine-side water pump 93, an engine water jacket, a thermostat 94, a linear three-way valve 95, a radiator 96, and the like. A cooling water passage 91 is provided, and a passage 97 for guiding engine waste heat to the heat exchanger 63 is provided.
This passage 97 branches off the main cooling water passage 91 via a linear three-way valve 95 on the way of the cooling water circulating in the main cooling water passage 91 from the engine water jacket to the radiator 96, and branches the heat exchanger 64. After passing through, it is formed to join the main cooling water passage 91.

The linear three-way valve 95 is connected to the main cooling water passage 9.
The rate at which the cooling water is diverted from 1 to the passage 97 can be linearly changed. The cooling water that has received the engine waste heat is guided to the linear three-way valve 95, and is moved to the operating position of the linear three-way valve 95. The heat exchanger 64 is guided to the heat exchanger 64 via the passage 97 by a corresponding amount.
Thus, the engine waste heat is supplied to the low-pressure refrigerant in the suction side line 42 of the refrigerant circuit 30.

FIG. 2 shows a control system of the air conditioner. The control system shown in this figure includes a system CPU 100 for controlling the entire system and an engine CPU 106 for controlling the engine 2.
6 are electrically connected so that control can be performed in relation to each other. Further, to the system CPU 100, an operation unit 101 provided in the indoor unit 1a, refrigerant temperature sensors 86 and 87, an indoor temperature sensor 88, an electronic expansion valve 34, and an indoor fan 102 are connected, and a high pressure provided in an outdoor unit is provided. Side pressure sensor 81, low pressure side pressure sensor 82, outside air temperature sensor 85, accumulator liquid level sensors (temperature sensors) 61, 62, compressor temperature sensors 24, 25, refrigerant temperature sensors 77, 78, 79, 8
4, defrost switch 103, four-way valve 31, linear three-way valve 9
5. The outdoor fan 104 and the control valve 37 are connected. A memory 105 for storing programs, various data, and the like is connected to the system CPU 100.

The operation mode (cooling or heating) and set temperature are determined by the operation unit 101, and the four-way valve 31 is switched and controlled according to the operation mode, and the operation mode, set temperature and various sensors are used. The electronic expansion valve 34, the indoor fan 102, the linear three-way valve 95, the outdoor fan 104,
The control valve 37 and the like are controlled.

The operation of the air conditioner of this embodiment as described above will be described below.

During the cooling operation of the air conditioner, the four-way valve 3
As shown by a broken line in FIG. 1, control is performed such that the discharge side line 41 and the line 65 are connected and the suction side line 42 and the line 70 are connected. As a result, the high-pressure refrigerant discharged from the compressor 20 is discharged by the discharge side line 41, the four-way valve 31, the line 65, the line 65, the outdoor heat exchanger 32, the line 66, as indicated by a broken line arrow in FIG.
Line 75, electronic expansion valve 34, indoor heat exchanger 33, line 74, line 70, four-way valve 31, and suction side line 42
To the compressor 20 in this order.

Accordingly, the outdoor heat exchanger 32 serves as a condenser, and radiates heat here.
Becomes an evaporator, where heat is absorbed,
The room is cooled.

On the other hand, during the heating operation, the four-way valve 31
As shown by a solid line, the state is controlled so that the discharge-side line 41 and the line 70 are connected and the suction-side line 42 and the line 65 are connected. Thereby, the compressor 20
As shown by the solid arrows in FIG. 1, the high-pressure refrigerant discharged from the discharge side line 41, the four-way valve 31, the line 70,
Line 74, indoor heat exchanger 33, electronic expansion valve 34, line 75, line 66, outdoor heat exchanger 32, line 65,
It returns to the compressor 20 through the four-way valve 31 and the suction side line 42 in this order.

Accordingly, the indoor heat exchanger 33 functions as a condenser, and heat is radiated here to heat the room, and the outdoor heat exchanger 32 functions as an evaporator, where heat is absorbed. Will be

In this embodiment, the bypass passage 36 is formed so as to connect the upstream of the indoor heat exchanger 33 serving as a condenser and the upstream of the outdoor heat exchanger 32 serving as an evaporator during a heating operation. In the heating operation, an unbalance between the heat radiation capacity and the heat absorption capacity occurs such that the heat absorption capacity of the outdoor heat exchanger 32 is relatively lower than the heat radiation capacity of the indoor heat exchanger 33. , The control valve 37 of the bypass passage 36 is opened.

More specifically, when the outside air temperature is low during the heating operation and frost forms on the outdoor heat exchanger 32 serving as an evaporator, the control valve 37 is opened. Based on the detection of the low-pressure side refrigerant pressure by the pressure sensor 82, the detection of the low-pressure side refrigerant temperature by the refrigerant temperature sensor 84, or the detection of the outside air temperature by the outside air temperature sensor 85, the opening degree of the control valve 37 is increased as these are lower. You. This allows
The balance between the heat dissipation capacity of the indoor heat exchanger 33 and the heat absorption capacity of the outdoor heat exchanger 32 is appropriately adjusted.

When the control valve 37 is open as described above, the refrigerant flowing into the bypass passage 36 from the upstream of the outdoor heat exchanger 32 serving as an evaporator is in a high-temperature, high-pressure gaseous state, and has a volume and a flow rate of less. Although it is large, when passing through the heat exchanger 38, heat is released and condensed by heat exchange with a low-temperature refrigerant downstream of the control valve 37 to become a gas-liquid two-phase or liquid state,
Volume and flow rate are reduced. Therefore, the control valve 37
The noise when passing through is sufficiently reduced.

In this embodiment, the heat exchanger 38
In this configuration, heat exchange between the refrigerant upstream of the control valve 37 in the bypass passage 36 and the low-temperature low-pressure refrigerant in which the refrigerant that has passed through the indoor heat exchanger 33 and the electronic expansion valve 34 has joined the refrigerant that has passed through the bypass passage 36. As a result, the efficiency of heat exchange is enhanced, and the condensation of the high-temperature refrigerant and the noise reduction effect thereby are enhanced.

The heat exchanger 38 radiates and condenses the high-temperature refrigerant, and gives the heat to the low-pressure refrigerant, thereby heating the low-temperature and low-pressure refrigerant and causing the evaporator to heat the low-temperature and low-pressure refrigerant. It is effectively used to promote evaporation.

When the number of cooling target rooms is small during cooling, the air fan (not shown) of the indoor heat exchanger 33 in the unused room is stopped, and the electronic expansion valve 34 is fully closed. In this case, in order to prevent the condensing ability of the outdoor heat exchanger 32 and the heat absorbing ability of the indoor heat exchanger 33 from becoming unbalanced, the control valve 37 of the bypass passage 36 is opened and the throttle is set to an appropriate value. The refrigerant is flowed from the high pressure side to the low pressure side while depressurizing, bypassing the electronic expansion valve 34 and the indoor heat exchanger 33. In this case, the efficiency of the high-pressure side refrigerant can be improved by the heat exchanger 38 in a supercooled state. Further, among the refrigerants containing a large amount of the refrigerant liquefied through the outdoor heat exchanger 32 serving as a condenser, the gas-phase refrigerant is further liquefied in the heat exchanger 38,
Noise due to the refrigerant passing through the control valve 37 can be reliably prevented. The liquid-phase refrigerant passing through the bypass passage 36 can be vaporized by the heat exchanger 64.

The configuration of the bypass passage and the like in the heat transfer device of the present invention is not limited to the above embodiment, but can be variously changed. Hereinafter, various embodiments will be described with reference to FIGS. 3 to 9 schematically show the structure of the main part of the heat transfer device according to various embodiments. The same parts as those shown in FIG. 1 are denoted by the same reference numerals.

FIG. 3 is a modification of the embodiment (first embodiment) shown in FIG. 1, and the entire apparatus is composed of a compressor 20, a four-way valve 31, an outdoor heat exchanger 32, an indoor heat exchanger 33, and an electronic device. It is the same as the first embodiment shown in FIG. 1 in that the air conditioner is provided with an expansion valve 34 and the like and capable of switching between cooling and heating. Also, a bypass passage 36A connecting the high-pressure refrigerant circuit and the low-pressure refrigerant circuit.
The bypass passage 36A is formed so as to connect the upstream of the indoor heat exchanger 33 serving as a condenser and the upstream of the outdoor heat exchanger 32 serving as an evaporator during a heating operation. The point that a control valve 37A capable of adjusting the flow rate is provided and a heat exchanger 38A is provided is also similar to the first embodiment in FIG.

However, the heat exchanger 38A is provided with the control valve 3
The heat exchange is performed between the 7A upstream portion and the downstream portion of the control valve 37 in the bypass passage 36A (the portion before merging with the refrigerant passing through the indoor heat exchanger 33 and the expansion valve 34). .

According to this modification, the control valve 37A is controlled in the same manner as in the first embodiment, so that
Even when the outside air temperature is low during the heating operation, the balance between the heat dissipation capacity of the indoor heat exchanger 33 and the heat absorption capacity of the outdoor heat exchanger 32 is appropriately adjusted, and the noise generated when the refrigerant passes through the bypass passage 36A. Is sufficiently reduced.

FIG. 4 shows a second embodiment of the present invention. In this embodiment, in an air conditioner, a bypass passage 36B connecting a high-pressure refrigerant circuit and a low-pressure refrigerant circuit is connected to an outdoor heat source which becomes a condenser during a cooling operation. It is formed so as to connect the upstream of the exchanger 32 and the upstream of the indoor heat exchanger 33 serving as an evaporator.

That is, the overall configuration of the air conditioner capable of switching between cooling and heating, including the compressor 20, the four-way valve 31, the outdoor heat exchanger 32, the indoor heat exchanger 33, the electronic expansion valve 34, and the like, is the same as that of the first embodiment. However, the upstream end of the bypass passage 36B is connected to the line between the four-way valve 31 and the outdoor heat exchanger 32, and the bypass passage 36B is connected to the line between the electronic expansion valve 34 and the indoor heat exchanger 33. The downstream end is connected. The bypass passage 36B is provided with a control valve 37B capable of adjusting a flow rate and a heat exchanger 38B for exchanging heat between an upstream portion and a downstream portion of the control valve 37B.

When the electronic expansion valve 34 is provided in the indoor unit 1b in the passage configuration as in this embodiment, the bypass passage 36B must be provided over the outdoor unit 1a and the indoor unit 1b. So
It is preferable that the electronic expansion valve 34 be provided in the outdoor unit 1a so that the bypass passage 36B can be disposed in the outdoor unit 1a as shown in the drawing.

According to this embodiment, the refrigerant discharged from the compressor 20 is supplied to the four-way valve 31 as shown by the solid arrow in FIG.
Outdoor heat exchanger 32, electronic expansion valve 34, indoor heat exchanger 33
At the time of cooling to circulate back to the compressor 20 in this order, the heat absorption capacity of the indoor heat exchanger 33 (evaporator) is relatively lower than the heat dissipation capacity of the outdoor heat exchanger 32 (condenser). When such a situation occurs that the imbalance occurs, the control valve 37B of the bypass passage 36B is opened. For example, the outdoor heat exchanger 32 during cooling.
When the outside air temperature for exchanging heat with the indoor heat exchanger 33 is low.
And a small number of indoor units 1 provided with an outdoor heat exchanger 32 having a high heat radiation capacity corresponding to the heat absorption capacity of a plurality of
The control valve 37B is opened when only the cooling operation b is performed.

Based on the detection of the low-pressure side refrigerant pressure, the low-pressure side refrigerant temperature, or the outside air temperature, the lower the temperature is, the larger the opening of the control valve 37B is. The balance of the heat absorption capacity of the exchanger 33 is appropriately adjusted.

As described above, when the control valve 37B is opened, the high-temperature and high-pressure refrigerant flowing into the bypass passage 36B radiates heat and condenses when passing through the heat exchanger 38B, thereby reducing the volume and the flow rate. , Control valve 37
The noise when passing through B is sufficiently reduced,
The operation of the heat exchanger 38B such that the heat released from the high-pressure side refrigerant is used for heating the low-pressure side refrigerant is the same as in the other embodiments.

FIG. 5 shows a third embodiment of the present invention. In this embodiment, in a refrigerator (including a refrigerator), a bypass passage 36C connecting a high-pressure refrigerant circuit and a low-pressure refrigerant circuit is provided.
Are formed to connect the upstream of the condenser 132 and the upstream of the evaporator 133.

That is, the refrigerant circuit 30 of the refrigerator or the refrigerator is connected to the discharge line 1 that communicates with the discharge port of the compressor 20.
A condenser 132 connected to the compressor 41 and an evaporator 133 connected to a suction side line 142 communicating with a suction port of the compressor 20.
And an electronic expansion valve 134 interposed between the condenser 132 and the evaporator 133. The refrigerant discharged from the compressor 20 is supplied to the discharge line 141, the condenser 132, the electronic expansion valve 134, and the evaporator 133. The compressor 133 and the suction side line 142 are circulated so as to return to the compressor 20 in this order.

The bypass passage 36C is connected to the compressor 20
From the electronic expansion valve 134 to the evaporator 133 and from the middle of the discharge-side line 141 to the condenser 132. In the bypass passage 36C, a control valve 37C capable of adjusting a flow rate,
A heat exchanger 38C for performing heat exchange between an upstream portion and a downstream portion of the control valve 37C is provided.

According to this embodiment, the condenser 1
In the case where an imbalance occurs in which the heat absorption capacity of the evaporator 133 is reduced with respect to the heat dissipation capacity of the condenser 32, for example, the heat capacity in the freezer (refrigerator) is reduced, and the heat dissipation capacity of the condenser 132 is unbalanced Occurs, the control valve 37C of the bypass passage 36C is opened. Further, at the time of the defrosting operation of the heat exchanger in the freezer (refrigerator), the control valve 37C of the bypass passage 36C is opened while the operation is continued.

In the state where the control valve 37C is opened, the refrigerant flowing from the high pressure side into the bypass passage 36C radiates heat and condenses when passing through the heat exchanger 38C, thereby reducing noise when passing through the control valve. At the same time, the operation of the heat exchanger 38C such that the heat released from the high-pressure side refrigerant is used for heating the low-pressure side refrigerant is the same as in the other embodiments.

In the refrigerant circuit shown by a solid line in FIG.
The evaporator 133 is adapted to subcool control (control for adjusting the opening degree of the electronic expansion valve so as to reduce the refrigerant temperature near the high-pressure side expansion valve to a temperature lower than the saturated liquid temperature).
Although the accumulator 46 is provided in the middle of the suction side line 142 between the compressor and the compressor 20, the superheat control (to increase the refrigerant temperature of the compressor suction section to a temperature higher than the saturated steam temperature). The receiver 150 may be interposed in a line between the condenser 132 and the electronic expansion valve 134 as shown by a two-dot chain line in FIG. .

FIG. 6 shows a fourth embodiment of the present invention. In this embodiment, in an air conditioner, a bypass passage 36D connecting a high-pressure refrigerant circuit and a low-pressure refrigerant circuit is provided during cooling.
It is formed so as to connect the upstream of the condenser and the downstream of the evaporator at any time during heating.

That is, the entire configuration of the air conditioner capable of switching between cooling and heating, including the compressor 20, the four-way valve 31, the outdoor heat exchanger 32, the indoor heat exchanger 33, the electronic expansion valve 34, etc., is the first and second embodiments. Is the same as the above, except that the four-way valve 31
In the discharge side line 41 leading to
The upstream end of 6D is connected, and in the middle of the suction side line 42 from the four-way valve 31 to the compressor 20 (preferably upstream of the accumulator 46 in the suction side line 42).
Is connected to the downstream end of the bypass passage 36D. The bypass passage 36D is provided with a control valve 37D capable of adjusting a flow rate and a heat exchanger 38D for exchanging heat between an upstream portion and a downstream portion of the control valve 37D.

According to this embodiment, when the required cooling capacity or the required heating capacity suddenly decreases during the cooling or heating operation, or when the high-pressure side pressure rises to a predetermined value or more for some reason, etc. The control valve 37D of the bypass passage 36D is opened in addition to the control of the engine or the like for reducing the rotational speed, so that the cooling capacity or the heating capacity is adjusted according to the demand or the abnormal increase of the high-pressure side pressure is prevented. Well done. That is, the load and the high-pressure side pressure are reduced only by controlling the engine or the like that lowers the compressor rotation speed.
Is opened, the reduction of the load and the high-pressure side pressure is promoted, and the responsiveness is enhanced.

In the state where the control valve 37D is opened, the refrigerant flowing from the high pressure side into the bypass passage 36D radiates heat and condenses when passing through the heat exchanger 38D, thereby reducing noise when passing through the control valve. At the same time, the operation of the heat exchanger 38D such that the heat released from the high-pressure side refrigerant is used for heating the low-pressure side refrigerant is the same as in the other embodiments.

FIG. 7 shows a fifth embodiment of the present invention. In this embodiment, in a refrigerator (including a refrigerator), a bypass passage 36 connecting a high-pressure refrigerant circuit and a low-pressure refrigerant circuit is provided.
E is formed to connect the upstream of the condenser 132 and the downstream of the evaporator 133.

That is, the compressor 20 and the discharge side line 14
1, condenser 132, electronic expansion valve 134, evaporator 133,
The entire configuration of the refrigerator including the suction side line 142 and the like is the third configuration.
Similar to the embodiment, except that the compressor 20
The upstream end of the bypass passage 36E is connected in the middle of the discharge-side line 141 up to the outlet, and the downstream end of the bypass passage 36E is connected in the middle of the suction-side line 42 from the evaporator 133 to the compressor 20. ing. And
A control valve 37 capable of adjusting a flow rate is provided in the bypass passage 36E.
E and a heat exchanger 38E for exchanging heat between an upstream portion and a downstream portion of the control valve 37E.

According to this embodiment, when the required refrigerating capacity drops rapidly, or when the high-pressure side pressure rises to a predetermined value or more for some reason, control of the engine or the like for reducing the compressor speed is performed. In addition to the above, the bypass passage 36
By opening the control valve 37E of E, adjustment of the refrigerating capacity or prevention of abnormal rise of the high-pressure side pressure is performed with good responsiveness.

In the state where the control valve 37E is opened, the refrigerant flowing from the high pressure side into the bypass passage 36E radiates heat and condenses when passing through the heat exchanger 38E, thereby reducing noise when passing through the control valve. The operation of the heat exchanger 38E, such as the heat released from the high-pressure side refrigerant being used for heating the low-pressure side refrigerant, is the same as in the other embodiments.

FIG. 8 shows a sixth embodiment of the present invention. In this embodiment, in an air conditioner, a second evaporator 160 is provided between an evaporator and a compressor of a low-pressure refrigerant circuit, and a high-pressure refrigerant is provided. A bypass passage (36F) connecting the circuit and the low-pressure refrigerant circuit is formed so as to connect the downstream of the condenser and a position between the evaporator and the second evaporator during cooling.

That is, the overall configuration of the air conditioner capable of switching between cooling and heating, including the compressor 20, the four-way valve 31, the outdoor heat exchanger 32, the indoor heat exchanger 33, the electronic expansion valve 34, etc. The fourth embodiment is substantially the same as the fourth embodiment, except that the second evaporator 16 is provided in the middle of the suction side line between the four-way valve 31 and the compressor 20.
0 is interposed. The second evaporator 160 may perform heat exchange between the refrigerant and the outside air, but may use a heater to enhance the evaporating effect, or drive the compressor 20 with a water-cooled engine. In this case, the refrigerant may be heated by engine cooling water for recovering engine waste heat.

The upstream end of the bypass passage 36F is connected to the middle of the line from the outdoor heat exchanger 32 to the electronic expansion valve 34, while the downstream end of the bypass passage 36F is connected to the room which becomes an evaporator during cooling. It is connected at a position between the heat exchanger 33 and the second evaporator 160 and is connected, for example, in the middle of a line from the indoor heat exchanger 33 to the four-way valve 31 as shown by a solid line, or a two-dot chain line. Is connected in the middle of the line from the four-way valve 31 to the second evaporator 160.

The connection position of the upstream end of the bypass passage 36F is determined by the position of the outdoor heat exchanger 32 in the outdoor unit side circuit.
, The outlet of the condenser in the high-pressure refrigerant circuit (the outdoor heat exchanger 32 during cooling) and the electronic expansion valve 34
Between the inlet of the condenser and the outlet of the condenser.

The bypass passage 36F is provided with a control valve 37F capable of adjusting a flow rate and a heat exchanger 38F for exchanging heat between an upstream portion and a downstream portion of the control valve 36F.

According to this embodiment, the refrigerant discharged from the compressor 20 is supplied to the four-way valve 31 as shown by the solid arrow in FIG.
During cooling, in which the heat is circulated through the outdoor heat exchanger 32, the expansion valve 34, and the indoor heat exchanger 33 in this order and returned to the compressor 20, the heat radiation capacity of the outdoor heat exchanger 32 (condenser) and the indoor heat exchanger When it becomes necessary to adjust the balance with the heat absorption capacity of the evaporator 33 (evaporator),
F is opened. For example, when the outside air temperature at which heat is exchanged with the outdoor heat exchanger 32 during cooling is low, or the outdoor heat exchanger 32 has a high heat radiation capability that matches the heat absorption capability of a plurality of indoor heat exchangers, and The bypass passage 36F is opened when only a small number of indoor units are operated for cooling.

Based on the detection of the low-pressure side refrigerant pressure, the low-pressure side refrigerant temperature, or the outside air temperature, the lower the temperature, the greater the degree of opening of the control valve 37F. The balance of the heat absorption capacity of the exchanger 33 is appropriately adjusted.

Further, even when the upstream end of the bypass passage 36F is connected between the outdoor heat exchanger 32 serving as a condenser during cooling and the electronic expansion valve 34 as described above, the electronic expansion valve 3
4 is provided on the indoor unit 1b side and the bypass passage 36F is provided on the outdoor unit 1a side,
The connection position of the bypass passage upstream end in the high-pressure refrigerant circuit is close to the outlet of the outdoor heat exchanger 32, and the distance from this position to the electronic expansion valve 34 becomes longer. The liquid refrigerant accumulates near the electronic expansion valve 34, and the refrigerant is likely to become gaseous near the bypass passage upstream end connection position.

For this reason, even in a configuration in which the upstream end of the bypass passage is connected to the downstream of the condenser, when the bypass passage is opened, a high-temperature, high-pressure gaseous refrigerant flows into the bypass passage, and is left as it is. Although noise is generated when passing through the control valve, the heat exchanger 38F provided in the bypass passage 36F
As a result, heat is released and condensed, so that noise is reduced.

The heat released from the high-pressure side refrigerant in the heat exchanger 38F is given to the low-pressure side refrigerant, and the low-pressure side refrigerant passes through the second evaporator 160.
The evaporation and vaporization of the low-pressure refrigerant are sufficiently performed.

FIG. 9 shows a seventh embodiment of the present invention. In this embodiment, in a refrigerator (including a refrigerator), a second evaporator 160 is provided between the evaporator 133 and the compressor 20 of the low-pressure refrigerant circuit. And a bypass passage 36G
Is formed so as to connect the downstream of the condenser 132 in the high-pressure refrigerant circuit and the position between the evaporator 133 and the second evaporator 160 in the low-pressure refrigerant circuit.

That is, the compressor 20 and the discharge side line 14
1, condenser 132, electronic expansion valve 134, evaporator 133,
The entire configuration of the refrigerator including the suction side line 142 and the like is the third configuration.
It is almost the same as the embodiment, except that the evaporator 133 and the compressor 20
In the middle of the suction side line 142 between the second evaporator 16
0 is interposed. The upstream end of the bypass passage 36G is connected to a position near the outlet of the condenser 132 in a portion between the outlet of the condenser 132 and the electronic expansion valve 134 in the high-pressure refrigerant circuit, while the downstream end of the bypass passage 36G is connected. The end is connected to a position between the evaporator 133 and the second evaporator 160.

The bypass passage 36G is provided with a control valve 37G capable of adjusting a flow rate and a heat exchanger 38G for exchanging heat between an upstream portion and a downstream portion of the control valve 37G.

Further, as shown by a solid line in FIG. 9, the accumulator 46 is provided downstream of the second evaporator 160,
Alternatively, as shown by a two-dot chain line in FIG.
A receiver 150 is provided upstream of 34.

According to this embodiment, when it is necessary to adjust the balance between the heat radiation ability of the condenser 132 and the heat absorption ability of the evaporator 133, for example, a freezer (refrigerator)
When the heat capacity of the inside of the condenser 132 becomes unbalanced due to the reduced heat capacity, the control valve 37G of the bypass passage 36G is opened, so that the balance between the heat dissipation capacity and the heat absorption capacity is appropriately adjusted. You.

Also in this embodiment, the bypass passage 36
The upstream end of G is connected to a position near the outlet of the condenser 132 in a portion between the outlet of the condenser 132 and the electronic expansion valve 134 in the high-pressure refrigerant circuit. Even in the downstream, since the refrigerant is likely to be in a gaseous state, the gaseous high-pressure refrigerant flows into the bypass passage 36G when the control valve 37G of the bypass passage 36G is open, but the heat exchanger 3 provided in the bypass passage 36G
By performing heat dissipation and condensation at 8G, noise is reduced and the heat is given to the low-pressure refrigerant.

In each of the above embodiments, the compressor 2
The drive source for driving 0 is not limited to the illustrated engine 2 but may be an electric motor or the like.

Further, in the refrigerant circuit of each embodiment, a capillary tube may be used as a throttle for expanding the refrigerant between the condenser and the evaporator instead of the electronic expansion valves 34 and 134 shown in the drawings. Good.

[0089]

As described above, according to the present invention, in a refrigerant circulation type heat transfer device, a bypass passage for connecting a high pressure refrigerant circuit and a low pressure refrigerant circuit in parallel with a throttle is provided, and the degree of opening is adjusted in the middle of the bypass passage. A possible pressure reducing valve is provided, and a heat exchanger for performing heat exchange between an upstream portion and a downstream portion of the pressure reducing valve is provided. For this reason, in the case where suppression of the pressure increase in the high-pressure refrigerant circuit and adjustment of the balance between the heat radiation capability and the heat absorption capability are required, a part of the refrigerant in the high pressure refrigerant circuit is opened by opening the bypass passage. In this case, the high-pressure refrigerant flowing into the bypass passage from the high-pressure refrigerant circuit is condensed by the heat exchanger, so that noise when the high-pressure refrigerant passes through the pressure reducing valve can be sufficiently suppressed. it can.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of a refrigerant circulation type heat transfer device of the present invention.

FIG. 2 is a block diagram illustrating a control system of the device according to the first embodiment.

FIG. 3 is a schematic circuit configuration diagram of a main part of a refrigerant circuit showing a modification of the device of the first embodiment.

FIG. 4 is a schematic circuit configuration diagram of a main part of a refrigerant circuit showing a second embodiment of the device of the present invention.

FIG. 5 is a schematic circuit configuration diagram of a main part of a refrigerant circuit showing a third embodiment of the device of the present invention.

FIG. 6 is a schematic circuit configuration diagram of a main part of a refrigerant circuit showing a fourth embodiment of the device of the present invention.

FIG. 7 is a schematic circuit configuration diagram of a main part of a refrigerant circuit showing a fifth embodiment of the device of the present invention.

FIG. 8 is a schematic circuit configuration diagram of a refrigerant circuit main part showing a sixth embodiment of the device of the present invention.

FIG. 9 is a schematic circuit configuration diagram of a main part of a refrigerant circuit showing a seventh embodiment of the device of the present invention.

[Explanation of symbols]

1a Outdoor unit 1b Indoor unit 2 Engine 20 Compressor 30 Refrigerant circuit 32 Outdoor heat exchanger 33 Indoor heat exchanger 34 Electronic expansion valve 36, 36A, 36B, 36C, 36D, 36E, 36
F, 36G bypass passage 37, 37A, 37B, 37C, 37D, 37E, 37
F, 37G control valve (reducing valve) 38, 38A, 38B, 38C, 38D, 38E, 38
F, 38G heat exchanger 132 condenser 133 evaporator 160 second evaporator

Claims (4)

[Claims] 1. A refrigerant circulation type heat transfer device having a refrigerant circuit for circulating refrigerant discharged from a compressor through a condenser, a throttle, and an evaporator so as to return to the compressor, wherein the refrigerant is throttled from the compressor through a condenser. A bypass passage connecting a high-pressure refrigerant circuit to the compressor and a low-pressure refrigerant circuit from the restrictor to the compressor via the evaporator in parallel with the restrictor; A refrigerant circulation type heat transfer device, comprising: a heat exchanger for performing heat exchange between an upstream portion and a downstream portion of the pressure reducing valve in the bypass passage. 2. The refrigerant circulation heat transfer according to claim 1, wherein the bypass passage connects the upstream portion of the condenser in the high-pressure refrigerant circuit to the upstream portion of the evaporator in the low-pressure refrigerant circuit. apparatus. 3. The refrigerant circulation type heat transfer according to claim 1, wherein the bypass passage connects an upstream portion of the condenser in the high-pressure refrigerant circuit and a downstream portion of the evaporator in the low-pressure refrigerant circuit. apparatus. 4. A high pressure refrigerant circuit comprising a second evaporator between the evaporator and the compressor in the low pressure refrigerant circuit, wherein the bypass passage is provided in a portion between an outlet of the condenser and an inlet of the throttle in the high pressure refrigerant circuit. 2. The refrigerant circulation heat transfer device according to claim 1, wherein a position near the outlet of the condenser is connected to a position between the evaporator and the second evaporator in the low-pressure refrigerant circuit.