JPH1038410A - Refrigerant circulation type heat transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a leakage of refrigerant and a damage due to a rise in refrigerant pressure in a high-pressure side refrigerant circuit of a refrigerant circulation type heat transfer device for an air conditioner, etc., and keep the temperature of refrigerant flowing through a compressor from rising abnormally. SOLUTION: A section of a high-pressure side refrigerant circuit between a compressor 8 and a condenser and a section of a low pressure side refrigerant circuit between an expansion valve 38 and an evaporator are connected by bypass lines 20 and 105 provided with on-off control valves 21 and 104. A pressure sensor 101 is provided to detect the pressure in the high-pressure side refrigerant circuit. When the pressure detected by the pressure sensor 101 is high, the bypass lines 20 and 105 are opened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used as a refrigerating device, a heat pump device and an air conditioner, and circulates a refrigerant in the order of a compressor, a condenser, an expansion valve, an evaporator and a compressor. The present invention relates to a refrigerant circulation type heat transfer device that takes in heat into a refrigerant and releases heat from the refrigerant in a condenser.

[0002]

2. Description of the Related Art In a refrigerant circulation type heat transfer device, a portion between a compressor and a condenser in a high pressure side refrigerant circuit from a compressor to an expansion valve and a low pressure side refrigerant circuit from an expansion valve to a compressor are provided. A part between the evaporator and the compressor is connected by a bypass passage, and a pressure sensor for detecting the pressure of the high-pressure side refrigerant circuit is arranged. When the detected pressure is high, the bypass passage is conducted. Some have valve means.

[0003]

According to the above apparatus,
For example, when the compressor abnormally rotates at a high speed, when the capacity of the condenser is particularly reduced due to a fan abnormality or limitation of the number of operating units, or when the opening degree of the expansion valve is particularly small, the abnormality of the high-pressure side refrigerant circuit is caused by some abnormality. It is possible to prevent a situation in which the pressure rises abnormally, and to prevent refrigerant leakage from each part of the high-pressure side refrigerant circuit and damage caused by an abnormal pressure rise.

However, the refrigerant bypassed between the evaporator and the compressor in the low-pressure side refrigerant circuit has a high temperature and a high pressure, and is sucked into the compressor again, compressed and discharged to increase the pressure of the refrigerant in the high-pressure side refrigerant circuit. I do. Then, the refrigerant continues to circulate through the compressor, the high-pressure side refrigerant circuit, the bypass, the low-pressure side refrigerant circuit, and the compressor, and the temperature gradually increases. Therefore, there is a problem that the lubrication function of the compressor is reduced and the compressor is damaged. In addition, when the temperature of the compressor rises above a predetermined value, if the driving device for driving the compressor is emergency stopped, the driving device will stop, and the continuous operation of the refrigerant circulation type heat transfer device itself will not be possible. It will be impossible.

[0005] In view of the above, the present invention not only prevents the refrigerant from leaking or being damaged due to an increase in the refrigerant pressure in the high-pressure side refrigerant circuit, but also causes the temperature of the refrigerant passing through the compressor to be abnormal. It is an object of the present invention to provide a refrigerant circulation type heat transfer device which can be prevented from rising.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, according to the present invention, a compressor is operated by a driving device, and a compressor, a condenser, an expansion valve, an evaporator,
In a refrigerant circulation type heat transfer device that circulates refrigerant in the order of a compressor, a portion between a compressor and a condenser in a high pressure side refrigerant circuit from a compressor to a expansion valve through a condenser, and an evaporator from an expansion valve. And a pressure sensor for detecting the pressure of the high-pressure side refrigerant circuit by connecting the portion between the expansion valve and the evaporator in the low-pressure side refrigerant circuit to the compressor via the bypass path, and this pressure sensor The valve means is arranged to make the bypass passage conductive when the detection pressure is high.

Further, in this refrigerant circulation type heat transfer device, the driving device is constituted by a water-cooled internal combustion engine, and the hot-water refrigerant exchanges heat with the hot water after cooling the water-cooled internal combustion engine. The evaporator is constituted by a heat exchanger.

Further, as described in claim 3, the compressor is operated by the driving device, and the compressor, the condenser, the expansion valve,
In a refrigerant circulation type heat transfer device that circulates refrigerant in the order of an evaporator and a compressor, a drive device is constituted by a water-cooled internal combustion engine, and a low-pressure side refrigerant circuit from an expansion valve to a compressor via an evaporator is cooled by an internal combustion engine. A hot water refrigerant heat exchanger for exchanging heat between the hot water and the refrigerant is arranged in parallel with the evaporator, and between the compressor and the condenser in the high pressure side refrigerant circuit from the compressor to the expansion valve through the condenser. And a portion of the low-pressure side refrigerant circuit between the expansion valve and the portion between the evaporator and the hot water refrigerant heat exchanger by a bypass path, and a pressure for detecting the pressure of the high-pressure side refrigerant circuit. A sensor is provided, and valve means for conducting the bypass when the pressure detected by the pressure sensor is high is provided.

Further, as described in claim 4, the compressor is operated by the driving device, and the compressor, the condenser, the expansion valve,
In a refrigerant circulation type heat transfer device that circulates refrigerant in the order of an evaporator and a compressor, a drive device is constituted by a water-cooled internal combustion engine, and a low-pressure side refrigerant circuit from an expansion valve to a compressor via an evaporator is cooled by an internal combustion engine. A hot water refrigerant heat exchanger for exchanging heat between the hot water and the refrigerant is arranged in series with the evaporator, and in the high pressure side refrigerant circuit from the compressor to the expansion valve through the condenser, between the compressor and the condenser. And a portion between the downstream side of the hot water refrigerant heat exchanger or the evaporator and the portion between the expansion valve and the expansion valve, and detects the pressure of the high-pressure side refrigerant circuit. A pressure sensor is provided, and valve means for conducting the bypass when the pressure detected by the pressure sensor is high is provided.

Further, as described in claim 5, the compressor is operated by the driving device, and during heating, the compressor, the four-way valve, the indoor heat exchanger, the expansion valve, the outdoor heat exchanger, the four-way valve, and the compressor are operated. In the refrigerant circulation type heat transfer device consisting of an air conditioner that circulates the refrigerant in the order of the refrigerant, the compressor during cooling, the four-way valve, the outdoor heat exchanger, the expansion valve, the indoor heat exchanger, the four-way valve, and the compressor during cooling, Of the refrigerant circuit that circulates the refrigerant, a pressure sensor that detects the pressure of the high-pressure side refrigerant circuit until the refrigerant discharged from the compressor reaches the expansion valve is arranged, and the refrigerant bypass means for heating operation. One or both of the cooling operation bypass means and the refrigerant bypass means are provided. In this configuration, the refrigerant bypass means for heating operation connects a portion of the refrigerant circuit from the compressor to the indoor heat exchanger via the four-way valve and a portion of the refrigerant circuit from the expansion valve to the outdoor heat exchanger. It comprises a bypass and valve means for conducting the bypass when the pressure detected by the pressure sensor is high in the heating operation state. The refrigerant bypass means for cooling operation is a bypass passage that connects a portion of the refrigerant circuit from the compressor to the outdoor heat exchanger via the four-way valve and a portion of the refrigerant circuit from the expansion valve to the indoor heat exchanger. And valve means for conducting the bypass when the pressure detected by the pressure sensor is high in the cooling operation state.

Further, in the refrigerant circulation type heat transfer device according to any one of claims 1 to 5, as described in claim 6, a rotation speed for detecting an operation rotation speed of the compressor or the driving device. A sensor is provided so that when the detected pressure is high, the amount of energy supplied to the driving device is reduced when the detected rotational speed is equal to or higher than a predetermined value, and the bypass path is conducted when the detected rotational speed is equal to or lower than the predetermined value. It is characterized by having done.

[0012]

According to the device of the present invention having the above-described structure, the high-temperature and high-pressure refrigerant that passes through the bypass and reaches the low-pressure side refrigerant circuit passes through the evaporator (or hot-water refrigerant heat exchanger), which essentially absorbs heat. When passing through, heat is dissipated, the temperature drops, and a pressure drop occurs.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a refrigerant circulation type heat transfer device of the present invention will be described with reference to the drawings.

FIG. 1 schematically shows an air conditioner as an example of a refrigerant circulation type heat transfer device according to the present invention.
Is a water-cooled spark ignition type gas engine that drives the compressor 8 of the refrigerant via the transmission 2. The transmission 2 provided between the engine 1 and the compressor 8 is:
The belt 5 is stretched between pulleys 4 and 7 fixed to the output shaft 3 of the engine 1 and the input shaft 6 of the compressor 8, respectively.

The engine 1 is provided with a refrigerant circuit 10 for circulating refrigerant by a compressor 8 and a cooling water circuit 50 for cooling the engine 1 and recovering waste heat. In the circuit 50, an engine cooler (cooling water jacket) 63 and an exhaust gas heat exchanger 62 provided in an exhaust pipe are incorporated as a waste heat supply unit for cooling water.

The refrigerant circuit 10 is a circuit for circulating refrigerant such as chlorofluorocarbon by the compressor 8, and the compressor 8 and the oil separator 30 are connected by the pipe 11, and the oil separator 30 and the four-way valve 32 are connected by the pipe 12 , The four-way valve 32 and the double-pipe heat exchanger 33 are connected by the pipe 13, the double-pipe heat exchanger 33 and the plurality of outdoor heat exchangers 34 are connected by the branch pipe 14, and the outdoor heat The exchanger 34 and the distributor 36 are connected by a plurality of pipes 15,
Distributor 36 and liquid-gas heat exchanger 37 are connected to line 1
6, the liquid-gas heat exchanger 37 and the plurality of indoor heat exchangers 40 are connected by the pipe line 17 via the electronic expansion valves 38 respectively arranged in the branch portions 17a, and the indoor heat exchanger 40 And the four-way valve 32 are collectively connected by the pipe 18, and the four-way valve 32 and the compressor 8 are connected by the pipe 19 via the liquid-gas heat exchanger 37 and the accumulator 45.

An oil return passage extending from the oil separator 3 for returning the oil separated from the refrigerant in the oil separator 30 to the compressor 8 is provided in a pipe 19 between the accumulator 45 of the refrigerant circuit 10 and the compressor 8. 31
Are connected via a capillary tube 70 on the way.

The outdoor heat exchanger 34 disposed between the pipeline 14 and the pipeline 15 is provided with a fan 35 for blowing air to the outdoor heat exchanger 34. A dryer 41 and strainers 42 and 44 are provided for the plurality of electronic expansion valves 38 and the indoor heat exchanger 40 arranged in parallel with the pipe 18.

A flexible pipe 100 is disposed in the middle of the pipe 11, and a high-pressure side temperature sensor 103 for detecting the temperature of the refrigerant passing through the pipe 11, and a high-pressure side sensor between the compressor 8 and the electronic expansion valve 38. A high-pressure side pressure sensor 101 for detecting a refrigerant pressure of the refrigerant circuit is provided. At the time of cooling, the high-pressure side refrigerant circuit includes a pipe 11, an oil separator 30, a pipe 12, and a four-way valve 3.
2, pipe 13, double pipe heat exchanger 33, pipe 14, outdoor heat exchanger 34, pipe 15, pipe 16, liquid-gas heat exchanger 37
And a pipe 17, and at the time of heating, the pipe 11, the oil separator 30, the pipe 12, the four-way valve 32, and the pipe 18. The compressor 8 has a compressor temperature sensor 1
06, a flexible tube 100 is arranged in the middle of the pipeline 19, respectively. Further, a low-pressure side pressure sensor 102 for detecting a refrigerant pressure in a low-pressure side refrigerant circuit between the electronic expansion valve 38 and the compressor 8 is disposed in the pipe 19. The low pressure side refrigerant circuit is
At the time of cooling, the pipeline 1, the four-way valve 32, and the pipeline 1 in which the liquid-gas heat exchanger 37 and the accumulator 45 are arranged on the way.
9 during heating, the pipeline 17 and the liquid-gas heat exchanger 3
3, line 16, line 15, outdoor heat exchanger 34, line 1
4. It is composed of a double pipe heat exchanger 33, a pipe 13, a four-way valve 32 and a pipe 19.

In the refrigerant circuit 10, a portion of the pipe 12 connecting the oil separator 30 and the four-way valve 32 and a portion of the pipe 19 connecting the four-way valve 32 and the compressor 8 which is located before the accumulator 45. A refrigerant bypass passage 20 is provided between the refrigerant bypass passage 20 and an opening / closing control valve 21 serving as a flow control valve and an opening / closing valve for adjusting the flow rate of the bypassed refrigerant. ing.

Further, the compressor in the high pressure side refrigerant circuit,
As a bypass connecting the portion between the condenser and the portion between the expansion valve and the evaporator in the low-pressure side refrigerant circuit, a second bypass 105 branching from the middle of the bypass 20 is provided. The end is connected to the conduit 16. The second bypass passage 105 is also provided with an opening / closing control valve 104.

On the other hand, in a cooling water circuit 50, an exhaust gas heat exchanger 62 is connected to a water pump 61 by a pipe 51, and an exhaust gas heat exchanger 62 provided in an exhaust pipe of the engine and a cooling water jacket 63 are connected to a pipe 52. The cooling water jacket 63 and the switching valve 64 are connected by the pipe 53, the switching valve 64 and the outdoor radiator 65 are connected by the pipe 54, and the outdoor radiator 65 and the water tank 67 are connected by the pipe 55, In the middle of the pipe 55 and the water pump 61
The pipe 57 and the switching valve 64 are connected by the pipe 56 via the double pipe heat exchanger 33, the exhaust gas heat exchanger 62 and the pipe 54 are connected by the pipe 58, and the pipe 5
8 and a water tank 67 are connected by a thin tube 59.

The conduit 58 is provided with a throttle valve 68, the conduits 58 and 59 are used as passages for venting air, and the conduit 55 is used as a passage for supplying cooling water, It is used as a passage for circulating cooling water from the radiator 65 toward the water pump. The outdoor radiator 65 is provided with a fan 66 for blowing air to the radiator 65.

The above-described refrigerant circuit 10 and cooling water circuit 5
The double-pipe heat exchanger 33 provided for 0 is for exchanging heat between the refrigerant flowing through both circuits and the cooling water.

Further, an intake pipe 117 is connected to the engine 1, an air cleaner 118 is disposed upstream of the intake pipe 117, and a mixer 119 for mixing gas fuel and a downstream of the mixer 119 are provided downstream of the intake pipe 117. A throttle valve 120 is provided. The throttle valve 120 is a throttle valve opening control actuator 11 composed of a step motor.
1 is controlled to open and close. A gas outlet is provided in the venturi portion of the mixer 119, and the outlet has a fuel gas flow control valve 112, a pressure reducing valve 113, and two opening / closing valves 114 in the middle thereof. The connected gas supply line 116 is connected. Further, an exhaust pipe 123 is connected to the engine 1, and exhaust gas can be discharged to the atmosphere via an exhaust gas heat exchanger 62 provided in the middle of the exhaust pipe 123. The engine 1 is provided with an engine speed sensor 110 for detecting the engine speed.

FIG. 2 is a control block diagram of this embodiment. The CPU 140 has an engine speed sensor 110, a high pressure side pressure sensor 101, a high pressure side temperature sensor 103, a low pressure side pressure sensor 102, and a temperature attached to the compressor. From the sensor 106, rotation speed information, high pressure side pressure information, high pressure side temperature information, low pressure side pressure information and temperature information are input.
The CPU 140 determines the open / close control valve 21 based on the program and stored data in the memory 141 and information from each sensor.
A gas bypass valve 1 for controlling the opening and closing of a gas bypass valve consisting of: an opening / closing control actuator 21a;
An opening / closing control actuator 104a, an electronic expansion valve opening / closing control actuator 38a for controlling opening / closing of the electronic expansion valve 38,
The indoor heat exchanger fan drive actuator 40a, the outdoor heat exchanger fan drive actuator 35a, the switching valve 64 or a linear three-way valve drive actuator 64a for driving a linear three-way valve as described below, the fuel gas flow control valve drive actuator 112a, the throttle valve The opening control actuator 111a and the ignition circuit 113 are controlled respectively.

The operation of the air conditioner of this embodiment having the above-described structure will be described below.

First, in the cooling water circuit 50, a water pump 61
Is discharged from the exhaust gas heat exchanger 62 provided in the exhaust pipe of the engine, and is heated and then supplied to the cooling water jacket 63. The heated cooling water passes through line 5
It is guided to the switching valve 64 through 3.

The switching valve 64 is a thermostat valve,
When the temperature of the cooling water is equal to or lower than 78 ° C., the pipe 54 is closed and the cooling water is caused to flow toward the pipe 56.
It operates to supply the cooling water to the water pump 61 again.

When the temperature of the cooling water exceeds 78 ° C., a part of the cooling water flows toward the pipe 54 via the switching valve 64 to release heat from the outside air blown by the fan 66 from the outdoor radiator 65. From the pipe 55 to the water pump 61 through the pipe 57 and a part of the cooling water from the switching valve 64 to the double pipe heat exchanger 3.
3, and the refrigerant is heated at the same time.

Further, when the temperature of the cooling water exceeds 86 ° C., the switching valve 64 closes the pipe 56 to the double heat exchanger 33 and fully opens the pipe 54, so that all of the high-temperature cooling water is removed. It flows toward the outdoor radiator 65 and cools the cooling water strongly. At this time, since the cooling water is not sent to the double pipe heat exchanger 33, the cooling water and the refrigerant in the double pipe heat exchanger 33 And the heat exchange between them is stopped.

In such a configuration, during the cooling operation, high-temperature and high-pressure refrigerant flows from the compressor 8 to the double-tube heat exchanger 33 through the pipe 13, Since heat exchange between the cooling water and the refrigerant is difficult to be performed, the temperature of the cooling water is likely to be 78 ° C. or more, and the temperature of the cooling water is 86 ° C.
When the temperature exceeds ° C, all of the cooling water flows from the pipe 54 toward the radiator 65 by the switching valve 64 as described above,
After releasing heat to the outside air, the water pump 61
Will be sent to

The switching valve 64 is a linear three-way valve, in which a cooling water temperature sensor, an operation state detecting device, and a linear three-way valve drive control device are disposed, and the switching valve 64 is supplied to the double heat tube exchanger 33 and the outdoor radiator 65. The cooling water ratio may be controlled.

In this case, for example, when all of the plurality of indoor heat exchangers 40 are operated during the heating operation, all of the cooling water is supplied through the pipe 56 to the double pipe heat exchanger 33. In this case, all of the engine waste heat is transferred by the cooling water to the non-evaporated portion of the refrigerant that has been lowered in temperature and pressure by the expansion valve 38 and absorbed by the outdoor heat exchanger 34 by the expansion valve 38, and Efficiency will be increased.

However, when the cooling water temperature is too high, or when the amount of heat radiated from each indoor heat exchanger 40 decreases,
A large amount of cooling water is circulated through the outdoor radiator 65 to lower the temperature of the cooling water so that the engine can be sufficiently cooled.

In the refrigerant circuit 10, the four-way valve 32 is switched as shown by a broken line in the cooling operation in the refrigerant circuit 10 as shown in FIG. The high-pressure refrigerant discharged from the compressor 8 after the passage 18 and the conduit 19 are connected to each other is supplied from the conduits 11, 12, and 13 to the double-tube heat exchanger 33 and the outdoor After passing through the heat exchanger 34, via the pipes 15, 16, 17,
The refrigerant is guided from the expansion valve 38 to the indoor heat exchanger 40, cools the room, and is returned to the compressor 8 via the pipes 18 and 19.

That is, during the cooling operation, the high-temperature and high-pressure refrigerant discharged from the compressor 8 is hardly heated by the cooling water in the double heat exchanger 33 because of the high temperature. And then liquefied by releasing the heat of condensation, after which the residual heat is absorbed by the liquid-gas heat exchanger 37 and then rapidly expanded by the expansion valve 38 before being evaporated from the outside air by the indoor heat exchanger 40 Take away heat and vaporize.

The liquid-gas heat exchanger 37 mainly absorbs the residual heat of the refrigerant liquefied in the outdoor heat exchanger 34 during the cooling operation to the refrigerant vaporized in the indoor heat exchanger 40 to thereby improve the cooling efficiency. The heat exchange function is low during heating.

On the other hand, during the heating operation, the four-way valve 32 is switched as shown by the solid line in the figure, the pipes 12 and 18 are connected, and the pipes 13 and 19 are connected. The high-pressure refrigerant discharged is guided to the indoor heat exchanger 40 through the strainers 44 through the pipes 11, 12, and 18, as indicated by solid arrows in the drawing, and the condensed heat is removed by the indoor heat exchanger. The room is heated by discharging and liquefying.

After the high-pressure refrigerant liquefied in the indoor heat exchanger 40 is decompressed by the expansion valve 38, the refrigerant
7 through the liquid-gas heat exchanger 37, from the pipe 16 to the outdoor heat exchanger 34 through the distributor 36 and the pipe 15, and take the evaporation heat from the outside air to vaporize and then pass through the pipe 14. And guided to the double tube heat exchanger 33,
After receiving the engine waste heat with the cooling water in the double pipe heat exchanger 33, the waste heat is guided to the compressor 18 through the pipes 13 and 19, compressed again by the compressor 8 and discharged to the pipe 11.

When the number of the indoor heat exchangers 40 operating in the refrigerant circuit 10 is small during the heating operation, the indoor fans of the indoor units that do not operate are stopped, and the opening degree of the electronic expansion valve 38 is reduced to just before closing. As a result, the weight of the refrigerant that can pass through the electronic expansion valve 38 is reduced.

Even if the electronic expansion valve 38 of the operating indoor unit is fully opened, the pressure of the high-pressure side refrigerant upstream of the electronic expansion valve 38 increases. If the opening degree of the electronic expansion valve 38 of the operating indoor unit is fully opened, the amount of refrigerant flowing through the indoor heat exchanger 40 becomes excessive and heating becomes excessive, so that the opening degree of the electronic expansion valve of the operating indoor unit is moderate. And the pressure of the high-pressure side refrigerant is excessively increased.

If the pressure of the high-pressure side refrigerant is excessively increased, there is a problem in that each part of the high-pressure side refrigerant circuit is liable to be damaged by refrigerant leakage or high pressure. In addition, if the amount of heat absorbed by the outdoor heat exchanger 34 is not reduced in accordance with the small number of operating indoor units, the temperature of the refrigerant sucked into the compressor 8 via the accumulator 45 becomes too hot, The temperature of the compressor 8 rises, and the lubricating function of the compressor 8 deteriorates, causing a problem that the durability of the compressor 8 decreases. Also,
If the amount of heat absorbed by the outdoor heat exchanger 34 is excessive compared to the amount of heat released by the indoor heat exchanger 40, even if the engine speed is reduced, it is difficult to lower the high-pressure side refrigerant pressure, and the room of the operating indoor unit is heated. There are also problems that are overkill.

In addition, as described above, the rise of the high-pressure side refrigerant pressure beyond the normal range may be caused by a malfunction of the electronic expansion valve 38, a malfunction of the rotation speed of the engine 1, a failure of the double pipe heat exchanger 3, and the like.
3 and excessive rotation of the fan 35 of the outdoor heat exchanger 34.

In order to cope with such a problem, the bypass passage 20 bypassing the indoor heat exchanger 40 and the electronic expansion valve 38 is used.
The opening degree of the opening / closing control valve 21 is increased.
As a result, the insufficient degree of opening of the electronic expansion valve 38 is eliminated, the pressure of the high-pressure side refrigerant circuit decreases, and the bypass passage 2
Since the amount of the refrigerant flowing to zero flows into the indoor heat exchanger 40 in an amount corresponding to the operating indoor unit, the room in which the indoor unit operates is not overheated.

However, since there is no heat radiating part in the middle of the bypass passage 20, high temperature gas refrigerant is sucked into the compressor 8 as it is, and the problem that the temperature of the compressor 8 rises cannot be solved. In addition, since the high-pressure gas refrigerant is bypassed to the low-pressure refrigerant circuit, the pressure on the low-pressure side increases. As a result, unless the rotational speed of the engine 1 is reduced, the pressure of the high-pressure side refrigerant circuit is increased again as a result of the pressure increase by the compressor 8. Neither the pressure of the circuit nor the temperature of the compressor 8 can be effectively reduced.

Therefore, in the present embodiment, the second bypass passage 105 is provided as described above, and when the pressure of the high-pressure side refrigerant circuit is equal to or higher than a predetermined value, the opening / closing control valve 104 is opened to detect the high-pressure side pressure. The opening increases as the value increases. For this reason, at the time of heating, the high-pressure refrigerant that is bypassed from the pipe 12 to the pipe 13 is cooled when passing through the outdoor heat exchanger 34 that originally functions as an evaporator at the time of heating, and after the pressure and the temperature are reduced. The liquid is further cooled by the liquid-gas heat exchanger 37 and sucked into the compressor 8 via the accumulator 45. This prevents the temperature of the compressor 8 from rising, and also reduces the excessive pressure in the high-pressure side refrigerant circuit.

When the electronic expansion valve 38 is not disposed on the indoor unit side but is disposed on the part A in the middle of the conduit 16 on the outdoor unit side, the detected value of the high pressure side pressure sensor during cooling is not sufficient. If the value is equal to or more than the predetermined value, the open / close control valve 104 is opened.
As a result, the high-temperature and high-pressure refrigerant passes through the second bypass passage 105, radiates heat from the pipe 17 when passing through the indoor heat exchanger 40 which normally functions as an evaporator during cooling, and increases the temperature of the compressor 8 and the high pressure. Piping damage can be prevented.

FIG. 3 is a flowchart of the control in the apparatus of this embodiment.

In this embodiment, the opening / closing control of the opening / closing control valve 104 is performed in the heating operation state. After starting, it is determined in step S1 whether or not a stop signal of the air conditioner is present. A stop process for completely closing 112 or further causing the ignition circuit 113 to misfire is performed in step S2. On the other hand, if there is no stop signal, it is determined in step S3 whether the discharge pressure, that is, the detection value of the high pressure side pressure sensor is higher than the upper limit of the target pressure. If the detected value is higher than the target pressure upper limit, the process proceeds to step S4, and it is determined whether the engine speed is equal to or lower than the lower limit of the target engine speed range. Where N
If it becomes O, the process proceeds to step S5, where the throttle valve 1
20 or further reduce the fuel gas flow control valve 112
By reducing the engine speed.

That is, when the detected value is higher than the target pressure upper limit, the efficiency of the compressor 8 is reduced, and the heat radiation efficiency in the condenser (in the heating state, the indoor heat exchanger 40) is reduced. Therefore, in order to reduce the pressure in order to solve this problem, it is necessary to lower the engine speed or open the open / close control valve 21 or the open / close control valve 104. Step S5 is after detecting that there is room to reduce the engine speed in step S4. In this step, prior to opening the on-off valves 21 and 104,
First, the engine speed is reduced.

If the engine speed is equal to or lower than the lower limit value of the target engine speed range in step S4, the engine speed cannot be reduced further and the on-off valve 2
The process proceeds to step S6 in preparation for the opening operation of steps 1 and 104.
In this step, the open / close state of the gas bypass valves, that is, the open / close control valves 21 and 104, is determined. On the other hand, it is already detected in step S4 that the engine speed is equal to or lower than the lower limit value of the target engine speed range. It is necessary to increase the engine speed because there is no room to sufficiently follow the case. In the present embodiment, in this step, in order to increase the rotation speed at which the refrigerant circulation amount to the indoor side does not decrease, the throttle valve 12
0 is slightly opened, or the fuel gas flow control valve 112 is slightly opened.

If the open state of the gas bypass valves, that is, the open / close control valves 21 and 104 is detected in step S6, the process proceeds to step S8, where the detection value of the high pressure side pressure sensor is determined to be an abnormality determination value (for example, leakage of the high pressure side refrigerant circuit or other leakage). It is determined whether or not the pressure drop is immediately determined to be necessary in order to prevent the occurrence of damage.
Proceed to 9 to stop the engine 1. At this time, the fuel gas flow control valve 112 and both on-off valves 114 are fully closed.
If the detected value of the high-pressure side pressure sensor is smaller than the abnormality determination value in step S8, the process proceeds to step S10, in which the open / close control valves 21 and 104 are kept open, and the engine speed is equal to or less than the lower limit value of the target engine speed range. Has already been detected in step S4, and this state is maintained.

In step S3, if the detected value is smaller than the target pressure upper limit, the process proceeds to step S11, and it is determined whether the detected value is lower than the target pressure lower limit. If the detected value is lower than the lower limit of the target pressure, the pressure difference due to the expansion valve becomes smaller, the amount of refrigerant circulated cannot be increased, and a problem such as a decrease in capacity occurs. Therefore, control to increase the engine speed is performed. Therefore, it is determined in step S12 whether the engine speed is equal to or higher than the upper limit value of the target engine speed range. If the result of this determination is NO, the engine speed can be increased. Therefore, in step S13, the opening of the throttle valve is increased to increase the engine speed, or the opening of the fuel gas flow control valve 112 is further increased. Increase. At this time, the gas bypass valve, that is, the on-off control valve 2
The open / close state of 1,104 is not changed.

If the result of the determination in step S12 is YE
In the case of S, the engine speed cannot be increased, and the open / closed state of the gas bypass valves, that is, the open / close control valves 21 and 104, is determined in step S14. If the gas bypass valve is open in this determination, step S1
Proceeding to 5, the both open / close control valves 21 and 104 are closed. When both open / close control valves 21 and 104 are closed, the pressure of the high-pressure side refrigerant circuit increases, and the amount of refrigerant circulating to the indoor unit increases. This makes it possible to reduce the engine speed. For this reason, in this embodiment, in step S15, the engine speed is reduced until the amount of refrigerant circulated to the indoor unit becomes substantially equal to the amount before the two on-off control valves 21 and 104 are closed.

If it is determined in step S14 that both the open / close control valves 21 and 104 are closed, the open / close control valve 2
Since it is impossible to increase the high-pressure side refrigerant pressure or to lower the engine speed below the upper limit value by the control of 1, 104, the opening degree of the throttle valve 120, the opening degree of the fuel gas flow control valve 112, The opening degree of the bypass valves, that is, the opening / closing control valves 21 and 104, is not changed (step S1).
6). In order to increase the pressure of the high pressure side refrigerant circuit,
This is possible by restricting the electronic expansion valve 38, increasing the amount of circulating engine hot water to the double pipe heat exchanger 33 during heating, and the like.

If it is determined in step S11 that the detected value is larger than the target pressure lower limit value, the high-pressure refrigerant pressure is in an appropriate state, so that the opening degree of the throttle valve 120 and the fuel gas flow control valve 112 The opening degree and the opening degree of the gas bypass valves, that is, the opening / closing control valves 21 and 104, are not changed (step S17).

FIG. 4 shows systems showing an embodiment of an engine-driven refrigerator to which the present invention is applied. In this figure, the configuration of the intake system and exhaust system of the engine 1 is the same as that of the air conditioner of FIG. Cooling system is line 5 in engine 1
A cooling water circuit 50 composed of 1, 52, 53, etc., a water pump 61, an exhaust gas heat exchanger 62, a cooling water jacket 63, a thermostat 71 disposed in the middle of the cooling water circuit 50;
A linear three-way valve 72, a hot water refrigerant heat exchanger 73 in the accumulator 45, a branch water passage 74 branched from the thermostat 71, and a branch water passage 75 branched from the linear three-way valve 72.
And a radiator 65 arranged in the middle of the branch water channel 75. During warm-up, cooling water is circulated from the thermostat 71 to the branch water passage 74. Further, the linear three-way valve 72 allows the hot water flow I1 according to the required heat absorption of the accumulator 45 functioning as an evaporator to flow, while the water pump 6
The hot water flow rate I2 corresponding to an amount obtained by subtracting the hot water flow rate I1 from the discharge amount I of 1 is supplied to the radiator 65.

The refrigerant circuit includes a high-pressure side refrigerant circuit 125 from the compressor 8 to the electronic expansion valve 38 and a low-pressure side refrigerant circuit 126 from the electronic expansion valve 38 to the compressor 8. The high-pressure side refrigerant circuit 125 includes a high-pressure side upstream portion 125a from the compressor 8 to the condenser 130, and a high-pressure side downstream portion 125b from the condenser 130 to the electronic expansion valve 38. On the other hand, the low pressure side refrigerant circuit 126 includes a low pressure side upstream portion 126a from the electronic expansion valve 38 to the evaporator 131 and a low pressure side downstream portion 126b from the evaporator 131 to the compressor 8. An accumulator 45 provided with a hot water refrigerant heat exchanger 73 functioning as a second evaporator is disposed in the low pressure side downstream portion 126b. High pressure side upstream section 125a and low pressure side upstream section 12
A bypass passage 105 in which the open / close control valve 104 is disposed is disposed between the bypass passage 105 and the bypass passage 6a. Also in the present embodiment, when the detection pressure of the high-pressure side refrigerant pressure sensor becomes equal to or higher than a predetermined value, the opening / closing control valve 104 is opened, and the high-temperature and high-pressure refrigerant passing through the bypass 105 is originally an evaporating agent having an endothermic effect. The heat is radiated by the vessel 131.

In the figure, 130a is a fan provided for the condenser 130, 131a is a fan provided for the evaporator 131, and 121 is an electromagnetic clutch. Note that, instead of the bypass passage 105 in this embodiment, a bypass passage 105 ′ provided with an on-off control valve 104 ′ and a radiator 132 is provided in the middle, and the on-off control valve 104 ′ is detected by the detection pressure of the high-pressure side refrigerant pressure sensor 101. May be opened when the temperature exceeds a predetermined value or when the temperature detected by the temperature sensor 106 of the compressor 8 becomes higher than a predetermined value.

In this embodiment, the compressor 8 may be driven by an electric motor instead of the engine 1. In this case, the accumulator 45 is merely for preventing the liquid refrigerant from flowing out to the compressor, and the heat exchanger 73 in the accumulator 45 is eliminated.

Also, as in another embodiment shown in FIG.
The accumulator (not shown) is different from the embodiment shown in FIG.
1 is provided in parallel with the refrigerant circuit 126c.
A double-tube heat exchanger 133 may be arranged at 6c to circulate hot water of the engine.

Further, as in still another embodiment shown in FIG. 6, the refrigerant circuit 126c differs from the embodiment shown in FIG.
, The double-pipe heat exchanger 134 may be arranged between the evaporator 131 and the accumulator 45 to circulate the hot water of the engine 1. The bypass 10
5 'may be connected to an intermediate portion between the evaporator 131 and the double tube heat exchanger 134 in the low pressure side downstream portion 126b. When the temperature of the high-temperature and high-pressure gas refrigerant is higher than the temperature of the hot water, the temperature of the refrigerant can be reduced.

In the embodiment shown in FIG. 6, the evaporator 131 may be omitted.

FIG. 7 is a system diagram showing another embodiment of the engine driven air conditioner to which the present invention is applied. In this figure, the refrigerant discharged from the compressor 8 is sent to an oil separator 30 via a pipe 11, and further sent from the oil separator 30 to a four-way valve 32 via a pipe 12.
During the heating operation, the refrigerant flows in the direction of the solid arrow, and the four-way valve 3
The refrigerant is supplied to the indoor heat exchanger 40 from the pipe 2 through the pipe 18, and the refrigerant from the indoor heat exchanger 40 is sent from the pipe 17 a to the outdoor heat exchanger 34 through the expansion valve 38 and the pipe 17. Then, the air is sucked into the compressor 8 through the pipe 13, the four-way valve 32, and the pipe 19. In the refrigerant supply circuit, as the refrigerant bypass means for the heating operation, the pipes 200 and 201 connecting the pipes 12 and 17 and the open / close control valve 203 or the pipe 204 connecting the pipes 18 and 17 are provided. And open / close control valve 2
05 and the high-pressure side pressure sensor 1
01 is greater than or equal to a predetermined value, the opening / closing control valve 203
Alternatively, the opening / closing control valve 205 is opened. The pipe 19
A double-pipe heat exchanger 210 for circulating cooling water for the engine is disposed at the bottom.

During the cooling operation, the refrigerant flows in the direction of the dashed arrow,
The refrigerant is supplied from the four-way valve 32 to the outdoor heat exchanger 34 through the pipe 13, and the refrigerant from the outdoor heat exchanger 34 is supplied to the pipe 17.
Is sent to the indoor heat exchanger 40 through the expansion valve and the pipe 17a, and is further sucked into the compressor 18 through the pipe 18, the four-way valve 32, and the pipe 19. In the refrigerant supply circuit, pipes 12 and 17 are provided as refrigerant bypass means for cooling operation.
a, the pipelines 200, 206 and the open / close control valve 207 connecting
Alternatively, one of the pipe 208 connecting the pipe 13 and the pipe 17a and the opening / closing control valve 209 is provided, and when the detection value of the high pressure side pressure sensor 101 is equal to or more than a predetermined value, the opening / closing control valve 207 or the opening / closing control valve 207 is provided. Valve 209 is opened.

According to the present embodiment, it is possible to prevent the high-pressure side refrigerant circuit from exceeding a predetermined value in both the cooling and heating operation states.

It is to be noted that either one of the refrigerant bypass means for the heating operation and the refrigerant bypass means for the cooling operation may be provided.

[0069]

According to the structure of the present invention, the high-temperature and high-pressure refrigerant that passes through the bypass and reaches the low-pressure side refrigerant circuit radiates heat when it passes through the evaporator that normally absorbs heat, and the temperature decreases. In addition, a pressure drop occurs. This prevents the compressor from movably raising the temperature and reduces the pressure of the high-pressure side refrigerant circuit.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of an air conditioner to which the present invention is applied.

FIG. 2 is a block diagram illustrating a control system of the air conditioner.

FIG. 3 is a flowchart illustrating an example of control.

FIG. 4 is a system diagram showing an embodiment of an engine-driven refrigerator to which the present invention is applied.

FIG. 5 is a system diagram showing another embodiment of the engine-driven refrigerator to which the present invention is applied.

FIG. 6 is a system diagram showing still another embodiment of the engine-driven refrigerator to which the present invention is applied.

FIG. 7 is a system diagram showing another embodiment of an air conditioner to which the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 8 Compressor 10 Refrigerant circuit 32 Four-way valve 34 Outdoor heat exchanger 38 Expansion valve 40 Indoor heat exchanger 45 Accumulator 20, 105 Bypass path 21, 104 Open / close control valve

Claims (6)

[Claims] 1. A refrigerant circulation type heat transfer device in which a compressor is operated by a driving device and a refrigerant is circulated in the order of a compressor, a condenser, an expansion valve, an evaporator, and a compressor. The part between the compressor and the condenser in the high pressure side refrigerant circuit leading to the valve, and the part between the expansion valve and the evaporator in the low pressure side refrigerant circuit from the expansion valve through the evaporator to the compressor. A pressure sensor for detecting the pressure of the high-pressure side refrigerant circuit connected by a bypass passage is disposed, and valve means for conducting the bypass passage when a pressure detected by the pressure sensor is high is disposed. Refrigerant heat transfer device. 2. The evaporator according to claim 1, wherein the drive unit comprises a water-cooled internal combustion engine, and the evaporator comprises a hot water refrigerant heat exchanger for exchanging heat between the hot water and the refrigerant after cooling the water-cooled internal combustion engine. 2. The refrigerant circulation type heat transfer device according to 1. 3. A refrigerant circulation type heat transfer device in which a compressor is operated by a driving device and a refrigerant is circulated in the order of a compressor, a condenser, an expansion valve, an evaporator, and a compressor, wherein the driving device is driven by a water-cooled internal combustion engine. In the low pressure side refrigerant circuit from the expansion valve through the evaporator to the compressor, a hot water refrigerant heat exchanger for exchanging heat between the hot water and the refrigerant after cooling the internal combustion engine is arranged in parallel with the evaporator, A portion between the compressor and the condenser in the high-pressure side refrigerant circuit reaching the expansion valve through the condenser, and an expansion valve and the evaporator or the hot water refrigerant heat exchanger in the low-pressure side refrigerant circuit. And a pressure sensor for detecting the pressure of the high-pressure side refrigerant circuit, and a valve means for conducting the bypass when the pressure detected by the pressure sensor is high. Characterized by being arranged Medium circulation type heat transfer device. 4. A refrigerant circulation type heat transfer device in which a compressor is operated by a driving device and a refrigerant is circulated in the order of a compressor, a condenser, an expansion valve, an evaporator, and a compressor, wherein the driving device is driven by a water-cooled internal combustion engine. In the low pressure side refrigerant circuit from the expansion valve to the compressor via the evaporator, a hot water refrigerant heat exchanger for exchanging heat between the hot water and the refrigerant after cooling the internal combustion engine is arranged in series with the evaporator, The part between the compressor and the condenser in the high-pressure side refrigerant circuit from the condenser to the expansion valve through the condenser, and the expansion valve and the downstream one of the hot water refrigerant heat exchanger or the evaporator A pressure sensor for detecting the pressure of the high-pressure side refrigerant circuit, and a valve means for conducting the bypass when the pressure detected by the pressure sensor is high. Characterized by the arrangement of Refrigerant circulation type heat transfer device. 5. A compressor is actuated by a driving device, and refrigerant is circulated in the order of a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger, a four-way valve, and a compressor during heating, and compressed during cooling. Machine, a four-way valve, an outdoor heat exchanger, an expansion valve, an indoor heat exchanger, a four-way valve, and a refrigerant circulation type heat transfer device including an air conditioner that circulates refrigerant in the order of a compressor. A pressure sensor for detecting the pressure of the high-pressure side refrigerant circuit until the refrigerant discharged from the compressor reaches the expansion valve is arranged, and the following refrigerant bypass means for heating operation and refrigerant bypass means for cooling operation And / or both are provided. Refrigerant bypass means for heating operation: a bypass path connecting a part of the refrigerant circuit from the compressor to the indoor heat exchanger via the four-way valve and a part of the refrigerant circuit from the expansion valve to the outdoor heat exchanger; Valve means for conducting the bypass when the pressure detected by the pressure sensor is high in the operating state. Cooling operation bypass means: a bypass path connecting a portion of the refrigerant circuit from the compressor to the outdoor heat exchanger via the four-way valve and a portion of the refrigerant circuit from the expansion valve to the indoor heat exchanger; Valve means for conducting the bypass when the pressure detected by the pressure sensor is high in the operating state. 6. A rotational speed sensor for detecting an operating rotational speed of the compressor or the driving device is provided, and when a detected pressure is high, an energy supply amount to the driving device is reduced when the detected rotational speed is a predetermined value or more. The refrigerant circulation type heat transfer device according to any one of claims 1 to 5, wherein when the detected rotation speed is equal to or less than a predetermined value, the bypass path is made conductive.