JPH11182970A - Refrigerant circulation type heat transfer apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform cooling or freezing regardless of the capacity of connected evaporators. SOLUTION: A refrigerant circuit is constituted such that the refrigerant discharged from a compressor in an outdoor unit 1A is returned to the compressor through the fixed throttle of the indoor unit 1B and an indoor heat exchanger via a condenser, and this heat transfer apparatus is provided with controllers 101 and 102 which control each of these units 1A and 1B. At temperature adjustment, the objective output value is set, according to the temperature difference between the detected value by an indoor temperature sensor 87 and the set temperature data 109, by the controllers 101 and 109, and the revolution of the compressor is controlled through the throttle operation motor of an engine 2 so that the detected value by the refrigerant suction pressure sensor 76 may be the objective pressure value. At this time, for the tolerable member of revolutions of the compressor, the lowest revolution is set so that the revolution may go higher, the larger this capacity is, according to the indoor machine capacity data 108.

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 device applied to an air conditioner or a refrigerator.

[0002]

2. Description of the Related Art Conventionally, cooling and freezing are performed by absorbing heat from an evaporator while circulating a refrigerant discharged from a compressor through a condenser, an expansion valve (throttle), and an evaporator so as to return to the compressor. The refrigerant circulation type heat transfer device (abbreviated as heat transfer device) described above is generally known.

When this type of heat transfer device is applied to an air conditioner or a refrigerator for cooling operation, for example, temperature adjustment in a room or a freezer is performed by controlling the actual temperature of the room or the like and the target temperature set by temperature setting means. The target pressure of the refrigerant in the low pressure circuit between the outlet of the expansion valve and the suction port of the compressor is set in accordance with the temperature difference between the compressor and the compressor so that the pressure of the refrigerant in the low pressure circuit becomes the target pressure. Is performed by feedback control for controlling the number of rotations.

[0004] In this case, for example, when the difference between the actual room temperature and the target temperature is large, the target pressure value is set low, and conversely, when the temperature difference is small, the target pressure is set high. When the difference between the set target pressure and the actual pressure is large, the compressor is controlled to increase the rotation speed of the compressor, and conversely, when the pressure difference is small, the compressor is controlled to decrease the rotation speed. I have to.

[0005] That is, when the difference between the actual temperature and the target temperature is large, the pressure difference of the refrigerant between the upstream and downstream of the throttle is increased by increasing the rotation speed of the compressor, and the refrigerant is circulated to the evaporator. Both increasing the amount of cooling to be performed and increasing the refrigerant suction effect of the compressor to lower the low pressure side pressure, thereby lowering the low pressure side refrigerant temperature, thereby promoting the heat absorption effect in the evaporator. Conversely, when the temperature difference is small, the pressure difference of the refrigerant between the upstream and downstream of the throttle is reduced by lowering the rotation speed of the compressor, thereby suppressing the heat absorption effect in the evaporator and reducing the indoor temperature. And so on. Similarly, in the heating operation of the air conditioner,
According to the difference between the set temperature in the room where the condenser is arranged and the actual room temperature, the larger the difference, the larger the target value of the pressure of the high pressure circuit from the compressor to the expansion valve through the condenser, and the higher the pressure. Feedback control for controlling the number of revolutions of the compressor has been performed so that the detected pressure value of the circuit becomes the target pressure.
Thereby, heat radiation corresponding to the required heat radiation amount in the condenser has been enabled.

[0006]

In the above-described air conditioners and refrigerators using a heat transfer device, the refrigerant discharged from the compressor is returned to the compressor through a condenser, a throttle, and an evaporator. Although a circulation circuit is configured, a plurality of evaporators are also provided in this circuit.For example, in an air conditioner, a plurality of evaporators and throttles are provided in parallel as indoor units, and each indoor unit is provided for each room. Generally, cooling is performed for each room by installing the air conditioner, and cooling of one room by a plurality of indoor units is generally performed. Similarly, for example, in an air conditioner, a plurality of condensers and a plurality of throttles are provided in parallel, each indoor unit is installed in each room, and heating is performed for each room, or one room is connected to a plurality of indoors. It is common to heat with a machine.

In an air conditioner or a refrigerator using a heat transfer device, the number of rotations of the compressor is controlled as described above in temperature adjustment. However, in this type of conventional control, the maximum number of rotations and the minimum number of rotations are previously determined. The number of the indoor units to be driven is generally set even in an apparatus having a plurality of evaporators (outdoor units) as described above. Regardless of the (connection capacity), a constant rotation speed is set as the maximum rotation speed and the minimum rotation speed, and the compressor is controlled within an allowable rotation speed range therebetween. Therefore, there are the following problems.

That is, when an allowable rotation speed range is set in an air conditioner having a plurality of outdoor units, the maximum rotation speed is determined by the capacity of the compressor and the like.
For example, there may be a case where the setting is relatively low based on the minimum connection capacity or a case where the setting is relatively high based on the maximum connection capacity.

Here, if the minimum rotational speed is set relatively low based on the minimum connection capacity, if the connection capacity is large, immediately before the thermo-off, that is, the target pressure value and the actual pressure value in the low-pressure circuit or high-pressure circuit, When the approximation is made, the rotational speed of the compressor is greatly reduced, and as a result, the pressure of the refrigerant at the upstream side of each throttle is too low, and the refrigerant passes through the throttle at a temperature higher than the saturated liquid temperature. There is a problem that the refrigerant in the liquid mixed state passes through the throttle and generates abnormal noise.

On the other hand, if the minimum number of revolutions is set relatively high based on the maximum connection capacity, when the connection capacity is small,
In some cases, the rotation speed cannot be reduced sufficiently due to the restriction of the minimum rotation speed.In such a case, the pressure difference of the refrigerant between the upstream and downstream of the throttle becomes large, and the evaporator is used for cooling and freezing operation. As the amount of circulating refrigerant to the compressor increases, the suction operation of the low-pressure refrigerant of the compressor does not decrease, and the pressure and temperature of the low-pressure circuit remain low, so that the heat absorption operation by the evaporator is promoted too much, and as a result, indoors Problems such as excessive cooling. Similarly, during the heating operation, the refrigerant circulation amount to the condenser increases, and the refrigerant discharge pressure of the compressor does not decrease, and the pressure and temperature of the high-pressure circuit remain high. Is promoted too much, and as a result, there arises a problem that the room is overheated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has a refrigerant circuit having a plurality of evaporators in a refrigerant circuit and performing cooling or freezing by absorbing heat in these evaporators. It is an object of the present invention to provide a refrigerant circulation type heat transfer device capable of appropriately performing cooling or freezing regardless of the connection capacity of an evaporator.
Further, in a refrigerant circulation type heat transfer device having a plurality of condensers in a refrigerant circuit and performing heating by absorbing heat in these condensers, heating can be appropriately performed regardless of the connection capacity of the condensers. It is an object to provide a refrigerant circulation type heat transfer device.

[0012]

In order to achieve the above object, the present invention is configured so that refrigerant discharged from a compressor is returned to the compressor through a condenser, a throttle, and an evaporator. A refrigerant circuit provided with a plurality of evaporators arranged in parallel, in a refrigerant circulation heat transfer device adapted to perform cooling or freezing by absorbing heat in the evaporators, a space to be cooled or frozen. Temperature detection means for detecting the temperature of the temperature, temperature setting means for setting a target temperature,
A pressure detecting means for detecting the pressure of the low pressure circuit from the throttle to the suction port of the compressor, and a difference between a temperature detected by the temperature detecting means and a target temperature set by the temperature setting means, The greater the temperature difference, the greater the pressure difference according to the difference between the pressure detected by the pressure detecting means and the target pressure set by the pressure setting means. Control means for controlling the number of revolutions of the compressor so that the number of revolutions increases as the number of revolutions increases. The number of rotations is controlled, and at least the minimum number of rotations is set according to the connection capacity of the evaporator, and the larger the capacity, the higher the number of rotations. .

According to this device, at the time of temperature adjustment, the target pressure with respect to the refrigerant pressure of the low pressure circuit is set according to the temperature difference between the actual temperature and the target temperature, and the actual refrigerant pressure becomes the set pressure. Thus, the rotation speed of the compressor is controlled within the range of the predetermined allowable rotation speed. At this time, the allowable rotation speed is set according to the connection capacity of the evaporator, and the minimum rotation speed is set such that the larger the capacity, the higher the rotation speed. Therefore, when the connection capacity of the evaporator is small, it is possible to prevent the throttle downstream pressure from excessively decreasing even when the rotation speed of the compressor falls to the minimum rotation speed immediately before the thermo-off or the like.
When the connection capacity of the evaporator is large, the pressure downstream of the throttle can be sufficiently reduced.

According to another aspect of the present invention, a refrigerant discharged from a compressor is returned to a compressor through a condenser, a throttle, and an evaporator. An evaporator is provided with a refrigerant circuit arranged in parallel, and in a refrigerant circulation type heat transfer device configured to perform cooling or freezing by absorbing heat in the evaporator, a temperature of a space to be cooled or frozen is detected. Temperature detecting means, a temperature setting means capable of setting a target temperature, a pressure detecting means capable of detecting a pressure of a low-pressure circuit from the throttle to a suction port of the compressor, and a detection by the temperature detecting means. A pressure setting unit for setting a target pressure of the low-pressure circuit based on a comparison result of a temperature with a target temperature set by the temperature setting unit and data indicating a connection capacity of the evaporator; According to the difference between the detected pressure and the target pressure set by the pressure setting means, within the allowable rotation speed range between a predetermined maximum rotation speed and the minimum rotation speed, as the pressure difference increases, the rotation increases. Control means for controlling the number of rotations of the compressor so that the number of the evaporators becomes higher, the pressure setting means increases the difference between the detected temperature and the target temperature, and increases the connection capacity of the evaporator, The target pressure is set low (claim 2).

According to this device, at the time of temperature adjustment, the target pressure with respect to the refrigerant pressure of the low-pressure circuit is set according to the temperature difference between the actual temperature and the target temperature, and the actual refrigerant pressure becomes the set pressure. Thus, the rotation speed of the compressor is controlled within the range of the predetermined allowable rotation speed. At this time, the rotation speed of the compressor is controlled within the range of the allowable rotation speed in which the maximum rotation speed and the minimum rotation speed are set to constant values, but as the connection capacity of the evaporator increases, the target pressure decreases. As a result, the compressor is controlled to rotate at a higher speed as the connection capacity increases. Therefore, when the connection capacity of the evaporator is small, the rotation speed does not increase enough to cause an excessive pressure drop downstream of the throttle even immediately before the thermo-off, and the connection capacity of the evaporator does not increase. Is large, the pressure downstream of the throttle can be sufficiently reduced.

Further, in order to achieve the above object, the present invention is configured so that refrigerant discharged from a compressor is returned to the compressor through a condenser, a throttle, and an evaporator. In a refrigerant circulation type heat transfer device provided with a refrigerant circuit in which a condenser is disposed in parallel and performing heating by heat radiation in the condenser, temperature detecting means for detecting a temperature of a space to be heated And, a temperature setting means capable of setting a target temperature, a high-pressure pressure detecting means capable of detecting a pressure of a high-pressure circuit from an outlet of the compressor to the throttle, and a target temperature set by the temperature setting means. Pressure setting means for setting the target pressure of the high-pressure circuit higher as the temperature difference is larger in accordance with the difference between the temperature detected by the temperature detector and the target pressure set by the pressure setting means and the high-pressure pressure detection. Control means for controlling the number of rotations of the compressor so that the number of rotations increases as the pressure difference increases, according to the difference between the detected pressure and the maximum number of rotations. The number of rotations of the compressor is controlled within the allowable number of rotations between the number of rotations, and at least the minimum number of rotations is set according to the connection capacity of the condenser. (Claim 3).

According to this device, at the time of temperature adjustment, the target pressure with respect to the refrigerant pressure of the high-pressure circuit is set according to the temperature difference between the target temperature and the actual temperature, and the actual refrigerant pressure becomes the set pressure. Thus, the rotation speed of the compressor is controlled within the range of the predetermined allowable rotation speed. At this time, the allowable rotation speed is set according to the connection capacity of the condenser, and the minimum rotation speed is set such that the larger the capacity, the higher the rotation speed. Therefore, in the case where the connection capacity of the condenser is large, when the rotation speed of the compressor has decreased to the minimum rotation speed immediately before the thermo-off or the like, it is possible to prevent an excessive decrease in the upstream pressure of the throttle. When the connection capacity of the throttle is small, it is possible to lower the rotation speed sufficiently to lower the pressure upstream of the throttle.

According to another aspect of the present invention, a refrigerant discharged from a compressor is returned to the compressor through a condenser, a throttle, and an evaporator. In a refrigerant circulation type heat transfer device provided with a refrigerant circuit in which a condenser is arranged in parallel and performing heating by absorbing heat in the condenser, temperature detecting means for detecting a temperature of a space to be heated Temperature setting means for setting a target temperature, high-pressure pressure detecting means for detecting the pressure of a high-pressure circuit from the outlet of the compressor to the throttle, and a target temperature set by the temperature setting means. Pressure setting means for setting a target pressure of the high-pressure circuit based on a difference between the temperature detected by the temperature detection means and data indicating a connection capacity of the condenser; and a target pressure set by the pressure setting means. According to the difference between the pressure detected by the pressure and pressure detection means, within an allowable rotation speed range between a predetermined maximum value of the maximum rotation speed and the minimum rotation speed, the pressure setting means, as the pressure difference is larger, Control means for controlling the rotation speed of the compressor so that the rotation speed is increased,
The target pressure is set to be higher as the difference between the target temperature and the detected temperature is larger and the connection capacity of the condenser is larger (claim 4).

According to this device, at the time of temperature adjustment, the target pressure with respect to the refrigerant pressure of the high-pressure circuit is set according to the temperature difference between the target temperature and the actual temperature, and the actual refrigerant pressure becomes the set pressure. Thus, the rotation speed of the compressor is controlled within the range of the predetermined allowable rotation speed. At this time, the rotation speed of the compressor is controlled within the range of the allowable rotation speed in which the maximum rotation speed and the minimum rotation speed are set to a constant value, but the larger the connection capacity of the condenser, the higher the target pressure. As a result, the compressor is controlled to rotate at a higher speed as the connection capacity increases. Therefore, when the connection capacity of the condenser is large, the rotation speed does not decrease so much as to cause an excessive pressure drop on the upstream side of the throttle even immediately before the thermo-off. Is small, the upstream pressure of the throttle can be sufficiently reduced.

In particular, in the above-described apparatus, a fixed aperture whose opening is fixedly set may be provided as the above-described aperture for the purpose of cost reduction or the like. Since the pressure of the low-pressure circuit or the pressure of the high-pressure circuit cannot be adjusted by controlling the opening of the throttle, the temperature is adjusted exclusively by controlling the rotation speed of the compressor. Therefore, in a device provided with such a fixed aperture, if the configuration according to any one of claims 1 to 4 is adopted (claim 5), the temperature can be adjusted more while achieving cost reduction. It can be performed appropriately.

[0021]

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 compressor 20 driven by the engine 2, a refrigerant circuit 30 for circulating a refrigerant by driving the compressor 20, and a cooling water circuit 90 for cooling the engine 2. Are provided.

An intake pipe 3 is connected to the engine 2.
An air cleaner 4 and a mixer 5 are connected to the intake pipe 3. A fuel supply pipe 6 connected to a fuel gas supply source (not shown) is connected to the mixer 5, and a flow control valve 7, a pressure reducing valve 8, and a solenoid valve 9 are interposed in the fuel supply pipe 6. ing. In the mixer 5, the supply of fuel gas and air to the engine is adjusted by the rotation of the throttle valve by the throttle operation motor 5a. An oil tank 11 is connected to an oil pan of the engine 2 via an oil supply pipe 10, and a solenoid valve 12 for adjusting an oil supply amount is provided in the oil pipe 10.

An exhaust pipe 13 extends from the engine 2, and an exhaust gas heat exchanger 14, an exhaust silencer 15, and a mist separator 16 are interposed in the exhaust pipe 13. Reference numeral 17 denotes a heater for adjusting the oil temperature in the oil pan of the engine 2, and reference numeral 18 denotes an exhaust gas heat exchanger 14.
And a drain treatment device for neutralizing drain water from the exhaust silencer 15 and the mist separator 16.

The compressor 20 comprises a multi-type compressor having two unit compressors 20a and 20b in the illustrated example. Each of the unit compressors 20a and 20b is an electromagnetic clutch 2a.
It is connected to the output shaft 22 of the engine via 1a and 21b. 23 is a heater for adjusting the oil temperature in the compressor 20. Reference numerals 24 and 25 are compressor temperature sensors for detecting a compressor temperature.

The refrigerant circuit 30 includes the compressor 20 and:
A compressor having a function of condensing the high-pressure refrigerant and radiating heat, a throttle having a function of expanding the condensed refrigerant to reduce the pressure, and an evaporator for evaporating the expanded refrigerant and absorbing heat;
Is returned to the compressor 20 through the condenser, the throttle, and the evaporator. In the present embodiment, the refrigerant circuit 30 is configured by the outdoor circuit 31 provided in the outdoor unit 1A and the indoor circuit 32 provided in the indoor unit 1B, and can be switched between cooling and heating, and has a plurality of locations. A four-way valve 33 for switching the refrigerant circulation path and an outdoor heat exchanger 34 that serves as a condenser during cooling and an evaporator during heating are provided in the outdoor circuit 31 to constitute an air conditioner capable of cooling and heating. , And an indoor heat exchanger 36 serving as an evaporator during cooling and a condenser during heating are provided in each of the indoor circuits 32 of the plurality of indoor units 1B.

The structure of the refrigerant circuit 30 will be specifically described. In the outdoor circuit 31, the compressor 20 and the four-way valve 3
3 between the discharge port of the compressor 20 and the first port of the four-way valve 33.
A discharge side line 38 connecting the port 33a and a suction side line 39 connecting the second port 33b of the four-way valve 33 and the suction port of the compressor 20 are provided.

An oil separator 40 is provided in the discharge line 38. A heater 41 is provided on the oil separator 40, and the temperature of the oil separator 40 is adjusted by the heater 41. Then, oil is guided from the oil separator 40 to the downstream side of the suction side line 39 via the strainer 42 and the capillary tube 43.

An accumulator 45 is provided on the suction side line 39, and the suction side line 39 is provided with a four-way valve 3
3, an upstream line 39a connecting the second port 33b of the third accumulator 45 to the inlet of the accumulator 45, and a line 39b connected to the outlet of the gas phase refrigerant of the accumulator 45.
9b has a capillary 46 and a parallel U-shaped line 39d
And a downstream end connected to the suction port of the compressor 2 via a one-way valve 44. Then, the gas-phase refrigerant and the liquid-phase refrigerant are separated by the accumulator 45, and the gas-phase refrigerant is sucked into the compressor 20 via the line 39b, the capillary 46, the line 39c and the like.

A predetermined high level position and a predetermined low level position of the accumulator 45 are connected to the line 39d by a passage having the strainer 47 and the capillary tube 48 and a passage having the strainer 49 and the capillary tube 50, respectively.
A heater 51 is provided for these passages, and sensors 52 and 53 for detecting the temperature of each passage are provided. Then, when the liquid-phase refrigerant is led out to the passage in accordance with the rise in the liquid level in the accumulator 45, a temperature change occurs in the passage heated by the heater 51, and this is detected by the sensors 52 and 53. Thereby, the sensor 5
Reference numerals 2 and 53 function as liquid level detection sensors that detect a state in which the liquid level in the accumulator 45 has risen to a predetermined high level position or a state in which the liquid level has dropped to a predetermined low level position.

Further, the accumulator 45 is provided with a sight glass 55 for checking the liquid level. In addition, the lower end of the accumulator 45 is connected to a line 39d via a passage 39e having a strainer 56 and a control valve 57 so that the oil in the accumulator 45 can be further discharged as needed while the operation is stopped. It is connected.

The accumulator 45 is provided with a heat exchanger 58 for absorbing heat from a refrigerant flowing through a line 63 described later, and is provided with a heater 59.

An outdoor heat exchanger 34 is connected to the third port 33c of the four-way valve 33 via a line 61, and a plate heat exchanger 62 is provided in the middle of the line 61. Further, a line 63 is connected to the outdoor heat exchanger 34, and the line 63 passes through a heat exchanger 58 provided on the accumulator 45 and reaches an end at a joint 64. In the middle of the line 63, a filter dryer 65 and a manual valve 66 are arranged.

A line 67 is connected to the fourth port 33 d of the four-way valve 33, and a manual valve 68 is arranged on the line 67, and an end of the line 67 reaches a joint 69.

Further, a bypass passage 70 is connected to the outdoor circuit 31 between a line 63 located on the outlet side of the outdoor heat exchanger 34 during cooling and a line 39a leading to the inlet of the accumulator 45. This bypass passage 70
, A strainer 71 and a control valve 72 composed of an electromagnetic valve whose opening can be adjusted are arranged.

In addition, the outdoor circuit 31 includes a refrigerant discharge temperature sensor 73 for detecting the refrigerant temperature of the discharge line 38, a refrigerant suction temperature sensor 74 for detecting the refrigerant temperature of the suction line 39, and a refrigerant for the discharge line 38. A refrigerant discharge pressure sensor 75 for detecting pressure, a refrigerant suction pressure sensor (pressure detecting means) 76 for detecting refrigerant pressure in the suction side line 39, and a refrigerant temperature at a portion on the outlet side of the outdoor heat exchanger 34 during cooling. Sensors such as a refrigerant heat exchange outlet temperature sensor 77 are provided.

Between the outdoor circuit 31 and the indoor circuit 32,
Lines 81 and 82 connected to the lines 63 and 67 via joints 64 and 69 are provided.

On the other hand, in the indoor circuit 32, the lines 83 and 84 branched from the lines 81 and 82 are connected to the fixed throttle 35 and the indoor heat exchanger 36, and the fixed throttle 35 and the indoor heat exchanger 36 are connected. It is connected via a line 85. Further, a refrigerant temperature sensor 86 for detecting a refrigerant temperature in the line 85 and an indoor temperature sensor 87 for detecting an indoor temperature are provided in the indoor unit 1B.

The cooling water circuit 90 includes a pump 91, a water jacket 92 of the engine 2, a radiator 93, thermostats 94a and 94b, and the like, and a cooling water line is disposed therebetween.

That is, a cooling water line 90a is led out from the discharge side of the pump 91, and this cooling water line 90a is connected to the exhaust gas heat exchanger 14 and the water jacket 92, and is connected to the exhaust gas heat exchanger 14 and the water jacket 92. A cooling water line 90b is connected to the cooling water outflow side, and the cooling water line 90b is connected to a first thermostatic switching valve 94a, and a line branched from the cooling water line 90b upstream of the thermostatic switching valve 94a. 90c is the second thermostatic switching valve 9
4b.

A cooling water line 90d and a cooling water line 90e extend from the first thermostatic switching valve 94a. The cooling water line 90d is connected to a radiator 93, and a cooling water line 90f is led out of the radiator 93. The cooling water line 90e passes through the plate heat exchanger 62 and then joins the cooling water line 90f. . Further, the downstream side of the cooling water line 90f is the second
The cooling water line 90g downstream of the thermostat switching valve 94b is connected to the suction side of the pump 91. The first thermostat switching valve 94b is configured to control the temperature of the cooling water in the cooling water line 90c, that is, the temperature of the cooling water in the cooling water line 90b to the first temperature.
When the temperature is lower than the predetermined temperature, the cooling water line 90c and the cooling water line 90g are connected, while the cooling water line 90f and the cooling water line 90g are shut off. This speeds up warm-up after the engine is started. The second thermostatic switching valve 94a connects the cooling water line 90b with the cooling water line 90d when the cooling water temperature of the cooling water line 90b is higher than a second predetermined temperature (a temperature higher than the first predetermined temperature). Meanwhile, the cooling water line 90b and the cooling water line 90e are shut off. This prevents overheating of the engine. When the temperature of the cooling water line 90b is equal to or lower than the second predetermined temperature, the second thermostatic switching valve 94a communicates the cooling water line 90b with the cooling water line 9e,
The cooling water line 90b and the cooling water line 90d are shut off.
Thus, when the temperature of the cooling water line 90b is between the first predetermined temperature and the second predetermined temperature, the cooling water that has recovered the engine waste heat flows to the panel heat exchanger 62, and is used for heating the low-pressure refrigerant during heating. used.

Reference numerals 95a and 95b denote cooling fans for both the radiator 93 and the outdoor heat exchanger 34;
6a and 96b are motors for driving the fans 95a and 95b, and 97 is a water tank connected to a cooling water line 90g via a cooling water supply line. Reference numeral 98 denotes a cooling water temperature sensor for detecting the temperature of the cooling water at the outlet of the engine water jacket, and reference numeral 99 denotes a cooling water temperature sensor for detecting the temperature of the cooling water at the outlet of the exhaust gas heat exchanger 14.

Next, the control system of the air conditioner shown in FIG.
This will be described with reference to the block diagram of FIG. This figure mainly shows the configuration of a control system relating to the refrigerant circuit 30.

As shown in the figure, the control system of the air conditioner
The outdoor unit control device 1 provided on the outdoor unit 1A side
01, and an indoor unit control device 102 provided on the indoor unit 1B side.
2 are electrically connected so that control can be performed in relation to each other.

The outdoor unit controller 101 includes a refrigerant discharge temperature sensor 73 and a refrigerant suction temperature sensor 7 also shown in FIG.
4. Refrigerant discharge pressure sensor 75, refrigerant suction pressure sensor 76, refrigerant heat exchange outlet temperature sensor 77, compressor temperature sensors 24 and 2.
5, cooling water temperature sensor 98, refrigerant heat exchange outlet temperature sensor 99,
Detection signals are input from the high-level and low-level liquid level detection sensors 52 and 53 of the accumulator 45, respectively. Further, although not shown in FIG. 1, detection signals from a rotation speed sensor 103 for detecting a compression rotation speed or an engine rotation speed, and an outside air temperature sensor 104 for detecting an outside air temperature, as shown in FIG. The connected number information 105 is also input to the outdoor unit control device 101. Note that the connection number information 105
Indicates the number of indoor units 1B controlled by the outdoor unit 1A, and is given by a signal from the indoor unit control device 102, an input operation, or the like.

From the outdoor unit controller 101, the control valve 72 of the bypass passage 70, the control valve 57 of the passage 39e, the outdoor fan motors 96a and 96b, the cooling water pump 91, and the liquid level of the accumulator 45 also shown in FIG. Heater 51 for heating the passage for detection, four-way valve 33, engine 2 and compressor 2
Control signals are sent to the clutches 21a, 21b and the like between the positions 0a, 20b. Further, a signal is also sent to the LED 106 for displaying an operation state and the like. In the figure, reference numeral 107 denotes a storage device for storing various setting data and the like, which stores data such as allowable rotation speed, which will be described later, set in the rotation speed control of the compressor 20. Further, to the pulse motor 5a for adjusting the throttle valve opening, to the flow control valve 7 for A / F control, to the solenoid valve 9 for fuel connection with the fuel gas supply source at the time of starting,
Control signals are output to the solenoid valves 12 for replenishment when the oil level in the oil pan is low.

On the other hand, the indoor unit controller 102 has a refrigerant temperature sensor 86 for detecting the temperature of the refrigerant in the line 85 and an indoor temperature sensor (for detecting the indoor temperature where the indoor heat exchanger 36 is disposed). Each of the detection signals from the temperature detecting means 87 is input, and indoor unit capacity data 108 indicating the indoor unit capacity and set temperature data 109 given by operating a temperature setting means (not shown) are also input. Then, a control signal is output from the indoor control device 102 to the indoor fan motor 200 of the indoor heat exchanger 36.

The above-mentioned control devices 101 and 102 include a four-way valve 3
3 is controlled to switch between cooling and heating. At the time of cooling operation or heating operation, the set temperature data 109 is set.
In order to properly adjust the temperature in the room in which the indoor heat exchanger 36 is disposed, the throttle operation motor 5
The number of rotations of the compressor 20 is controlled via a. That is, the pressure setting means and the control means in the present invention are constituted by the control devices 101 and 102.

Hereinafter, control of the compressor 20 performed by the control devices 101 and 102 will be described with reference to FIGS.

FIG. 3 shows a main routine for controlling the number of revolutions of the compressor 20. When this routine is started, the indoor unit capacity data 108, the detected value (outside air temperature) of the outside air temperature sensor 104, and the operating conditions are read (step). S1). Note that the indoor unit capacity of each indoor unit means that a predetermined amount of air at a predetermined temperature passes through the indoor heat exchanger 36 per predetermined time, and the cooling at the time of passing a refrigerant at a predetermined temperature through the indoor heat exchanger 36. The heat absorption capacity at the time of heating or the heat dissipation capacity at the time of heating.
6 is larger as the fin area for heat radiation or heat absorption is larger. The indoor unit capacity in the indoor unit capacity data 108 refers to an average indoor unit capacity obtained from individual indoor unit capacities of a plurality of connected indoor units.

As the operating conditions, for example, conditions such as cooling or heating, and normal control or abnormality avoidance control are read. The normal control and the abnormality avoidance control are performed by the compressor temperature sensors 24 and 25 and the refrigerant discharge pressure sensor 7.
5. Based on the outputs of the refrigerant suction pressure sensor 76, the cooling water temperature sensor 98, etc., the refrigerant circuit 30 is selected in a routine (not shown), for example, when the high-pressure side refrigerant pressure exceeds a predetermined pressure value.
When an abnormality occurs in the refrigerant circulating through the compressor, the compressor 20, the engine 2, or the like, the abnormality avoidance control is set, and otherwise, the normal control is selected.

Next, the allowable rotation speed (operating range) of the compressor 20, that is, the maximum rotation speed (maxNc) and the minimum rotation speed (m
inNc) is set (step S2). In step S2, a later-described subroutine program (FIG. 4) is executed.

When the allowable rotation speed is set, the pressure value of the refrigerant (current pressure), the output value of the rotation speed sensor 103 (the rotation speed (Nc0)), and the indoor temperature value of the indoor temperature sensor 87 during cooling are calculated. The maximum change in the target low pressure corresponding to the difference between the set temperature data 109 or the target pressure value of the target high pressure corresponding to the difference between the set temperature data 109 during heating and the room temperature, and the rotation speed of the compressor 20 Data indicating the amount (maxdNc) is read (step S3). Then, the current rotational speed (Nc0) of the compressor 20
Is obtained and the target rotation speed (Nc) of the compressor 20 is set (step S4).

Here, the pressure value of the refrigerant is the output value of the refrigerant discharge pressure sensor 75 during heating, and the output value of the refrigerant suction pressure sensor 76 during cooling. The target pressure value is obtained by comparing the output value of the room temperature sensor 87 with the set temperature data 1.
The lower the target pressure value, the larger the difference between the actual temperature in the room where the indoor heat exchanger 36 is disposed and the target temperature is set during cooling. . During heating, the larger the difference between the target temperature and the actual temperature, the higher the target pressure value is set. And
The amount of change (dNc) is based on a comparison between the target pressure value and the output value of the refrigerant suction pressure sensor 76, and the maximum amount of change (ma) is set such that the greater the pressure difference, the higher the rotational speed.
xdNc).

Then, the target rotation speed (Nc) is compared with the maximum rotation speed (maxNc) and the minimum rotation speed (minNc) (step S5).
The number of revolutions of 0 is controlled. Specifically, the target rotation speed (N
If c) is equal to or less than the minimum rotation speed (minNc), the compressor 20 is driven at the minimum rotation speed (minNc) (step S).
6) If the target rotational speed (Nc) exceeds the minimum rotational speed (minNc) and is less than the maximum rotational speed (maxNc), the compressor 2
0 is driven at the target rotation speed (Nc) (step S7),
If the target rotation speed (Nc) exceeds the maximum rotation speed (maxNc), the compressor 20 is driven at the maximum rotation speed (maxNc) (step S8). Then, the process returns to step S1.

That is, the rotation speed of the compressor 20 is feedback-controlled so that the output value of the refrigerant suction pressure sensor 76 becomes the target pressure value.

FIG. 4 is a subroutine for setting control of the allowable number of revolutions (operating range) performed in step S2. In this routine, it is first determined whether the setting is cooling or heating (step S11).

Here, at the time of cooling, indoor unit capacity data 1
08 is read (step S12).
xNc) is set (step S13), and operating conditions such as normal control or abnormality avoidance control are read (step S14), and the minimum rotation speed (minNc) is set (step S15).

These rotation speeds during cooling (maxNc, m
inNc) is based on the indoor unit capacity data 108 to be read, and the indoor unit capacity and their rotation speed (maxNc, min
Nc) is obtained from a table that defines the correspondence.

FIG. 5 is a table showing such a table at the time of cooling. As shown in this figure, the maximum rotation speed (maxNc) and the minimum rotation speed (minNc) are respectively the connection capacity of the indoor units (the product of the average indoor unit capacity and the number of connected units, or the indoor units of all the connected indoor units). The number of revolutions is set to increase at a constant rate with an increase in the integrated value of the machine capacity). However, the maximum rotation speed (maxNc) is
In consideration of the reliability of the compressor and the like, it is set to be a constant value above a predetermined indoor unit connection capacity. Further, the minimum rotation speed (minNc) has a different set value between the normal control and the abnormality avoidance control, and the minimum rotation speed (minNc) in the abnormality avoidance control is sufficiently lower than the normal control. Set to a number.

The maximum rotation speed (maxNc) and the minimum rotation speed (m
When (inNc) is set, data indicating these rotation speeds is stored (step S16).

On the other hand, at the time of heating, the detection value (outside temperature) of the outside temperature sensor 104 is read and the maximum rotation speed (maxN
c) is set (steps S17 and S18), and then the indoor unit connection capacity is read and the minimum number of revolutions (minNc) is set (steps S19 and S20).

The maximum number of revolutions (maxNc) and the minimum number of revolutions (minNc) during heating are determined in advance by the outside air temperature and the number of revolutions (mNc).
axNc, minNc).

FIG. 6 shows a table at the time of such heating. As shown in this figure, the maximum rotation speed (maxNc) is a substantially constant value below a predetermined temperature (2 ° in the example shown) when the outside air temperature changes while the indoor unit connection capacity is constant, When the temperature is higher than this temperature, the number of rotations is reduced as the temperature rises, and the rotation speed is set to a constant value again at a predetermined temperature (7 ° in the illustrated example) or higher.
Further, when the indoor unit connection capacity changes while the outside air temperature is constant, a plurality of types of tables having different maximum rotation speeds (maxNc) corresponding to the indoor unit connection are set.

On the other hand, the minimum number of revolutions (minNc) is set to a constant value irrespective of operating conditions such as normal control or abnormality avoidance control and the outside air temperature. This minimum rotation speed (minNc)
For, a plurality of types of tables having different rotation speeds are set according to the indoor unit connection capacity, and the minimum rotation speed (minNc) is set by selectively using one of the tables according to the indoor unit connection capacity. It is supposed to.

Thus, the maximum number of revolutions during heating (maxNc)
When the minimum rotation speed (minNc) is set, the process proceeds to step S16, where data indicating these rotation speeds is stored.

According to the air conditioner of this embodiment as described above, in the refrigerant circuit, the four-way valve 33 is switched according to the time of cooling and the time of heating, so that the outdoor heat exchanger 3
4. One of the indoor heat exchangers 36 is a condenser and the other is an evaporator, and the refrigerant discharged from the compressor 20 passes through the condenser, the fixed throttle 35 and the evaporator in this order, and the compressor 2
It is cycled back to zero.

That is, during the heating operation, the first port 33a and the fourth port 33d of the four-way valve 33 are connected, and the third port 33c and the second port 33b are connected. As a result, as indicated by the dashed arrow in FIG.
The refrigerant discharged from the compressor 20 to the discharge line 38 is
Line 67, joint 69, line 8 from the four-way valve 33
2 and is sent to each indoor unit 1B and guided to the indoor heat exchanger 36 serving as a condenser, where the heat is radiated and liquefied,
Heating is performed with the heat of condensation. Then, after passing through the fixed aperture 35, passing through the line 81, the joint 64, and the line 63,
After being guided to an outdoor heat exchanger 34 serving as an evaporator and absorbing heat there, the heat flows through a four-way valve 33 to a suction side line 39 and is returned to the compressor 20.

On the other hand, during the cooling operation, the first
The port 33a communicates with the third port 33c, and the fourth port 33d communicates with the second port 33b. Thereby, as indicated by a solid arrow in FIG. 1, the refrigerant discharged from the compressor 20 to the discharge line 38 is guided to the outdoor heat exchanger 34 serving as a condenser via the four-way valve 33, where the refrigerant is discharged. After the heat is radiated and liquefied, each indoor unit 1 passes from the line 63 through the joint 64 and the line 81.
B, and is guided to an indoor heat exchanger 36 serving as an evaporator through a fixed throttle 35, where the heat is absorbed and cooling is performed. Then line 82, joint 69, line 6
7, flows through the four-way valve 33 to the suction side line 39, and returns to the compressor 20.

During the cooling and heating operations, the compressor 2 is operated in accordance with the set temperature data 109 as described above.
An allowable rotation speed of 0 is set, and the rotation speed of the compressor 20 is feedback-controlled within the range through the throttle operation motor 5a, so that the temperature of the room in which the indoor heat exchanger 36 is disposed is adjusted. Will be

In particular, according to the air conditioner, during the cooling operation, the rotation speed of the compressor 20 is controlled as described above, so that the temperature is appropriately adjusted. That is, the compressor 20
In the rotation speed control, the minimum rotation speed (minNc) is increased with an increase in the indoor unit connection capacity, so that the minimum rotation speed is a constant value regardless of the indoor unit connection capacity. The minimum rotation speed (minNc) is uniformly set to a low value based on the device, that is, the minimum indoor unit connection capacity, or the minimum rotation speed (minNc) is uniformly set to a high value based on the maximum indoor unit connection capacity. The temperature of the room can be adjusted by optimizing the pressure of the refrigerant passing through the indoor heat exchanger serving as an evaporator, that is, the temperature of the refrigerant, without causing abnormal noise or excessive cooling as in the device described above.

This will be described more specifically with reference to the Mollier diagram of FIG. 7. In the refrigeration cycle of this type of apparatus, the gas phase refrigerant is compressed by the compressor to become high pressure and the enthalpy rises (a ₀ → b ₀ ), then the enthalpy is reduced by condensation and heat radiation in the condenser, and the refrigerant changes from the gas phase to the liquid phase (b ₀ → c ₀ ). (C ₀ → d ₀ ) Further, the enthalpy rises due to evaporation and heat absorption in the evaporator (d ₀ → a ₀ ), and a cooling function is exhibited by evaporation and heat absorption of the refrigerant in the evaporator. .

However, if the minimum rotation speed (minNc) is set to a constant value of a low rotation speed based on the minimum indoor unit connection capacity, for example, in the case of the maximum indoor unit connection capacity, immediately before the thermo-off, that is, the compression At the time when the refrigerant pressure on the suction side of the compressor approaches the target pressure value, when the compressor reaches the minimum rotation speed, the suction pressure does not increase, the low pressure side pressure increases, and the discharge pressure is low. Since the supply amount of the refrigerant passing through the outdoor heat exchanger 34 serving as a condenser is small, the pressure is more likely to be reduced, and the high pressure side pressure is reduced. As a result, the pressure difference of the refrigerant between the upstream and downstream of each throttle becomes small, and the amount of the refrigerant passing through the indoor heat exchanger 36 serving as an evaporator also decreases. For example, the refrigeration cycle changes as a ₁ → b ₁ → c ₁ → d ₁ → a ₁ in FIG. Thus the refrigerant passes through the aperture while temperature higher than the saturated liquid temperature, that is, passes through the aperture refrigerant containing vapor phase (refer to point c _1), and as a result, the abnormal sound is generated.

When the minimum rotation speed (minNc) is set to a constant value of the high rotation speed based on the maximum indoor unit connection capacity, for example, in the case of the minimum indoor unit connection capacity, the minimum rotation speed (minNc) is obtained. Also, the refrigerant supply amount cannot be sufficiently reduced with respect to the capacity, and the suction pressure of the compressor is large. As a result, the pressure difference between the upstream and downstream of the throttle becomes large, for example, the refrigeration cycle Is a ₂ → b ₂ → c in FIG.
₂ → d ₂ → a ₂ , which tends to cause the pressure and temperature of the refrigerant to drop too much, resulting in excessive cooling.

On the other hand, according to the apparatus of the above embodiment, the allowable rotation speed of the compressor 20 is set such that the minimum rotation speed (minNc) increases as the indoor unit connection capacity increases. When the connection capacity is maximum, it is possible to prevent the rotation speed of the compressor 20 from excessively decreasing immediately before the thermo-off, while when the indoor unit connection capacity is minimum,
The rotation speed of the compressor 20 can be sufficiently reduced.
Therefore, regardless of the indoor unit connection capacity, a ₀ → b ₀ → in FIG.
It is possible to perform an ideal refrigerant cycle as shown by c ₀ → d ₀ → a _0, and it is possible to appropriately perform temperature adjustment without generating abnormal noise or excessive cooling.

Further, in the apparatus of the above embodiment, the minimum rotation speed (minN
Since the value of c) is changed and the minimum rotation speed (minNc) is set to a value sufficiently lower than that of the normal control during the abnormality avoidance control, for example, a part of the refrigerant circuit 30 may be clogged. When an abnormality such as an increase in the pressure of the refrigerant occurs, the abnormality avoidance control is set, so that the rotation speed of the compressor 20 can be significantly reduced. Therefore, there is an advantage that an abnormal situation such as an unnecessary increase in the refrigerant pressure can be effectively avoided.

By the way, in the above apparatus, in controlling the rotation speed of the compressor 20 during cooling, the minimum rotation speed (minN
The allowable rotation speed of the compressor 20 is set so that c) becomes higher as the connection capacity of the indoor unit increases, whereby the rotation speed of the compressor 20 is maintained at a rotation speed suitable for the connection capacity of the indoor unit. However, for example, the minimum rotation speed (minNc) is set to a constant rotation speed irrespective of the indoor unit connection capacity similarly to this type of conventional apparatus, and the indoor unit connection capacity is set when the target rotation speed of the compressor 20 is set. The same effect can be obtained by taking into account the following.

That is, the minimum rotation speed (minNc) is set to a relatively low value based on the minimum indoor unit connection capacity.
On the other hand, when setting the target pressure value, the difference between the output value of the room temperature sensor 87 and the set temperature data 109, that is, the difference between the actual temperature in the room where the indoor heat exchanger 36 is disposed and the set temperature is set. The target pressure value is set to a lower value as it is larger and the indoor unit connection capacity is larger.

In this manner, the target rotation speed of the compressor 20 becomes higher as the indoor unit connection capacity increases.
Therefore, when the indoor unit connection capacity is the maximum, the rotation speed of the compressor 20 does not decrease so much as to impair the ideal state of the refrigeration cycle even immediately before the thermo-off or the like. On the other hand, when the indoor unit connection capacity is the minimum, the minimum rotation speed (minNc) is set based on the minimum indoor unit connection capacity as described above. Can be reduced.

Therefore, by performing such control, it is possible to perform an ideal refrigerant cycle as shown by a ₀ → b ₀ → c ₀ → d ₀ → a ₀ in FIG. The temperature can be appropriately adjusted without generating abnormal noise or excessive cooling.

Furthermore, even during heating, the magnitude of the indoor unit connection capacity is correlated with the magnitude of the condensation capacity. When the indoor unit connection capacity is large, even if the refrigerant discharge pressure from the predetermined compressor is not sufficient, As a result of the large capacity, the pressure on the high pressure side tends to decrease. Further, even with the refrigerant suction force from the predetermined compressor, the pressure on the high pressure side decreases, and the flow rate of the refrigerant passing through the outdoor heat exchanger 34 that passes through the throttle and becomes the evaporator on the low pressure side decreases. Since it evaporates more in the evaporator and becomes slightly overheated in some cases, it changes as a ₁ → b ₁ → c ₁ → d ₁ in FIG. That is, when the indoor unit connection capacity is large, unless the compressor rotation speed is set to be larger than when the indoor unit connection capacity is small, an abnormal sound is generated from the throttle. When the indoor unit connection capacity is small, the room is overheated.

In the above embodiment, the indoor unit 1
Although the fixed throttle 35 is used as the throttle provided in B, it is also possible to provide a variable throttle such as an electronic expansion valve whose opening can be adjusted in place of the fixed throttle 35. However, according to the fixed throttle 35, there is an advantage that the refrigerant circuit 30 can be configured at low cost, and it is advantageous to adopt the fixed throttle 35 in consideration of cost. According to the refrigerant circuit provided with the variable throttle, the temperature can be adjusted not only by controlling the rotation speed of the compressor 20 but also by controlling the opening degree of the variable throttle. However, the fixed throttle 35 as in the above embodiment is provided. According to the refrigerant circuit 30, the temperature can be adjusted only by controlling the rotation speed of the compressor 20. Therefore, the apparatus configuration of the present invention is particularly useful in an apparatus such as the above-described embodiment in which the fixed throttle 35 is provided from the viewpoint of appropriately performing temperature adjustment.

[0083]

As described above, the present invention relates to a refrigerant-circulating heat transfer apparatus which performs cooling or freezing by absorbing heat in an evaporator provided in a refrigerant circuit while circulating the refrigerant in the refrigerant circuit. In the temperature adjustment, a target pressure with respect to the refrigerant pressure of the low-pressure circuit is set according to a temperature difference between the actual temperature and the target temperature, and a predetermined allowable rotation speed is set so that the actual refrigerant pressure becomes the target pressure. Since the number of rotations of the compressor is feedback-controlled within the range, and according to the connection capacity of the evaporator, the minimum number of rotations in the allowable number of rotations is set so that the number of rotations increases as the capacity increases. The rotation speed of the compressor can be kept at an optimum rotation speed according to the connection capacity of the evaporator. Therefore, unlike a conventional device of this type, in which the value of the minimum rotation speed is fixed regardless of the connection capacity of the evaporator, cooling or refrigeration can be performed without causing abnormal noise or excessive cooling in the refrigerant circuit. It can be done properly.

In particular, in the above-described apparatus, a fixed aperture having a fixed opening degree may be provided as the aperture for the purpose of cost reduction or the like. In the above, if the above configuration is adopted, temperature adjustment can be appropriately performed while achieving cost reduction.

[Brief description of the drawings]

FIG. 1 is an overall circuit diagram showing an embodiment of the present invention applied to an air conditioner.

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

FIG. 3 is a flowchart showing a main routine for controlling the number of revolutions of the compressor.

FIG. 4 is a flowchart illustrating a routine of control for setting an allowable range (operating range) of the rotational speed.

FIG. 5 is a diagram showing a correspondence relationship between an indoor unit connection capacity and an allowable rotation speed during cooling.

FIG. 6 is a diagram showing a correspondence relationship between an outside air temperature and an allowable rotation speed with the indoor unit connection capacity as a parameter during heating.

FIG. 7 is a Mollier chart of a refrigeration cycle in the air conditioner.

[Explanation of symbols]

 2 Water-cooled gas engine 5a Throttle operation motor 20 Compressor 30 Refrigerant circuit 34 Outdoor heat exchanger 35 Fixed throttle 36 Indoor heat exchanger 70 Bypass passage 72 Control valve 76 Refrigerant suction pressure sensor 101 Outdoor unit control unit 102 Indoor unit control unit 1A Outdoor unit Unit 1B Indoor unit

Claims (5)

[Claims] 1. A refrigerant circuit in which a refrigerant discharged from a compressor is returned to the compressor through a condenser, a throttle, and an evaporator, and a refrigerant circuit in which a plurality of the evaporators are arranged in parallel. In the refrigerant circulation type heat transfer device provided to perform cooling or freezing by absorbing heat in the evaporator, a temperature detecting means for detecting a temperature of a space to be cooled or frozen, and a target temperature can be set. Temperature setting means,
A pressure detecting means for detecting the pressure of the low pressure circuit from the throttle to the suction port of the compressor, and a difference between a temperature detected by the temperature detecting means and a target temperature set by the temperature setting means, The greater the temperature difference, the greater the pressure difference according to the difference between the pressure detected by the pressure detecting means and the target pressure set by the pressure setting means. Control means for controlling the number of rotations of the compressor so that the number of rotations becomes higher as the number of rotations increases, and the control means controls the number of rotations of the compressor within an allowable rotation number range between a maximum rotation number and a minimum rotation number. The number of revolutions is controlled, and at least the minimum number of revolutions is set according to the connection capacity of the evaporator, and the larger the capacity is, the higher the number of revolutions is. Heat transfer device 2. A refrigerant circuit in which a refrigerant discharged from a compressor is returned to the compressor through a condenser, a throttle, and an evaporator, and a refrigerant circuit in which a plurality of the evaporators are arranged in parallel. In the refrigerant circulation type heat transfer device provided to perform cooling or freezing by absorbing heat in the evaporator, a temperature detecting means for detecting a temperature of a space to be cooled or frozen, and a target temperature can be set. Temperature setting means,
Pressure detecting means for detecting the pressure of the low-pressure circuit from the throttle to the suction port of the compressor; a result of comparison between the temperature detected by the temperature detecting means and the target temperature set by the temperature setting means; Pressure setting means for setting the target pressure of the low-pressure circuit based on data indicating the connection capacity of the device, and a preset pressure corresponding to the difference between the pressure detected by the pressure detection means and the target pressure set by the pressure setting means. Within the allowable rotation speed range between the maximum rotation speed and the minimum rotation speed of a certain value, control means for controlling the rotation speed of the compressor so that the rotation speed increases as the pressure difference increases, Wherein the pressure setting means is configured to set the target pressure lower as the difference between the detected temperature and the target temperature is larger and the connection capacity of the evaporator is larger. The mobile device. 3. A refrigerant circuit in which a refrigerant discharged from a compressor is returned to the compressor through a condenser, a throttle, and an evaporator, and a refrigerant circuit in which a plurality of the condensers are arranged in parallel. In a refrigerant circulation heat transfer device provided with a condenser for heating by heat radiation, a temperature detecting means for detecting a temperature of a space to be heated and a temperature setting means for setting a target temperature And a high-pressure pressure detecting means capable of detecting the pressure of the high-pressure circuit from the outlet of the compressor to the throttle, and according to a difference between the target temperature set by the temperature setting means and the temperature detected by the temperature detecting means. A pressure setting means for setting the target pressure of the high-pressure circuit higher as the temperature difference is larger; and a pressure setting means for setting the target pressure in accordance with a difference between the target pressure set by the pressure setting means and the pressure detected by the high-pressure pressure detecting means. difference Control means for controlling the number of revolutions of the compressor so that the number of revolutions increases as the number of revolutions increases, and the control means controls the compression rate within an allowable revolution number range between a maximum revolution number and a minimum revolution number. Control the speed of the machine, and
At least the minimum number of revolutions is set according to the connection capacity of the condenser, and the larger the capacity is, the higher the number of revolutions is. 4. A refrigerant circuit in which a refrigerant discharged from a compressor is returned to the compressor through a condenser, a throttle, and an evaporator, and a refrigerant circuit in which a plurality of the condensers are arranged in parallel. In a refrigerant circulation type heat transfer device provided with a condenser for heating by absorbing heat, a temperature detecting means for detecting a temperature of a space to be heated, and a temperature setting means for setting a target temperature And a high-pressure pressure detecting means capable of detecting the pressure of the high-pressure circuit from the outlet of the compressor to the throttle, and a difference between a target temperature set by the temperature setting means and a temperature detected by the temperature detecting means. Pressure setting means for setting the target pressure of the high-pressure circuit based on data indicating the connection capacity of the condenser, and according to the difference between the target pressure set by the pressure setting means and the pressure detected by the high-pressure detection means, Control means for controlling the rotational speed of the compressor such that the greater the pressure difference, the higher the rotational speed within the allowable rotational speed range between the maximum and minimum rotational speeds of a predetermined constant value; And the pressure setting means is configured to set the target pressure higher as the difference between the target temperature and the detected temperature is larger and the connection capacity of the condenser is larger. Circulating heat transfer device. 5. The refrigerant circulation heat transfer device according to claim 1, wherein in the refrigerant circuit, the throttle is a fixed throttle whose opening degree is fixedly set. .