JP5157580B2 - Refrigeration equipment - Google Patents

Description

  The present invention relates to a refrigeration apparatus such as an air cooling heat pump chiller.

  Conventionally, a refrigeration apparatus includes a compressor 101, an air heat exchanger 102, an expansion valve 103, and a water heat exchanger 104 (see Japanese Patent Application Laid-Open No. 2003-83644: Patent Document 1). .

  The compressor 101, the air heat exchanger 102, the expansion valve 103, and the water heat exchanger 104 are sequentially connected in an annular shape via a refrigerant flow path 110.

  The refrigerant flow path 110 is provided with a four-way valve 105 that changes the flow of the refrigerant during the cooling operation and the heating operation.

  One end of a bypass flow path 111 is connected to the refrigerant flow path 110 between the expansion valve 103 and the water heat exchanger 104, and a refrigerant regulator 106 is connected to the other end of the first bypass flow path 111. ing.

  The refrigerant flow of this refrigeration apparatus will be described. During the cooling operation, the refrigerant compressed by the compressor 101 is, in order, the four-way valve 105, the air heat exchanger 102, the expansion valve 103, and water as indicated by the solid line arrows. It returns to the compressor 101 through the heat exchanger 104. At this time, the air heat exchanger 102 serves as a condenser, and the water heat exchanger 104 serves as an evaporator.

  On the other hand, during the heating operation, as indicated by the dotted arrows, the refrigerant compressed by the compressor 101 sequentially passes through the four-way valve 105, the water heat exchanger 104, the expansion valve 103, and the air heat exchanger 102. Return to the compressor 101. At this time, the air heat exchanger 102 serves as an evaporator, and the water heat exchanger 104 serves as a condenser.

  Here, when the amount of refrigerant necessary for the refrigerant flow path 110 is compared between the cooling operation and the heating operation, the water heat exchanger 104 is more efficient in condensing the refrigerant than the air heat exchanger 102. The amount of refrigerant required for the refrigerant flow path 110 is smaller during the heating operation than during the time.

For this reason, at the time of heating operation, the excess refrigerant liquid flows into the refrigerant regulator 106 via the bypass channel 111 and is stored. On the other hand, during the cooling operation, the amount of refrigerant necessary for the refrigerant flow path 110 is insufficient, so that the refrigerant liquid flows from the refrigerant regulator 106 into the refrigerant flow path 110 to compensate for the shortage.
Japanese Patent Laying-Open No. 2003-83644 (FIG. 4)

  However, in the conventional refrigeration apparatus, the water temperature in the water heat exchanger 104 is relatively high, the internal pressure of the bypass channel 111 is high, the internal pressure of the refrigerant regulator 106 is low when the outside air is low, and the refrigerant regulator If the cooling operation is performed in a state where the internal pressure of 106 is lower than the internal pressure of the bypass flow path 111, the refrigerant flows back to the refrigerant regulator 106, resulting in a shortage of refrigerant in the refrigerant flow path during the cooling operation. It was. And there existed a problem which causes the abnormal stop by the action | operation of a low-pressure protective device or the freezing of a water heat exchanger by the refrigerant | coolant shortage in a refrigerant | coolant flow path.

  Therefore, an object of the present invention is to provide a refrigeration apparatus that can prevent a refrigerant shortage in a refrigerant flow path during cooling operation.

In order to solve the above problems, the refrigeration apparatus of the present invention provides:
A compressor, an air heat exchanger, an expansion mechanism, and a water heat exchanger;
The compressor, the air heat exchanger, the expansion mechanism, and the water heat exchanger are sequentially connected in a ring shape via a refrigerant flow path,
This refrigerant flow path is provided with a switching valve that changes the flow of refrigerant during cooling operation and heating operation,
One end of a first bypass channel is connected to the refrigerant channel between the expansion mechanism and the water heat exchanger, and a refrigerant regulator is connected to the other end of the first bypass channel,
One end of a second bypass channel is connected to the refrigerant channel between the air heat exchanger and the expansion mechanism, and the refrigerant regulator is connected to the other end of the second bypass channel,
Both ends of the third bypass channel are connected to the first bypass channel,
A first electrically driven valve is provided in the third bypass flow path,
A second electrically driven valve is provided in the second bypass flow path ;
A control unit electrically connected to the first electric drive valve and the second electric drive valve;
This control unit is characterized in that, during the cooling operation, the first electric drive valve is closed and the second electric drive valve is opened for a certain period of time when the cooling operation is started .

According to the refrigeration apparatus of the present invention, the compressor, the air heat exchanger, the expansion mechanism, the water heat exchanger, the switching valve, the refrigerant regulator, the first electric drive valve, and the second electric valve. This control unit closes the first electric drive valve during cooling operation, and opens the second electric drive valve for a certain period of time at the start of cooling operation, so that the water temperature in the water heat exchanger is Is relatively high, the internal pressure of the first bypass flow path is high, and the external pressure is low, the internal pressure of the refrigerant regulator is low, and the internal pressure of the refrigerant regulator is lower than the internal pressure of the first bypass flow path Thus, even if the cooling operation is performed, the internal pressure of the refrigerant regulator can be made higher than the internal pressure of the first bypass channel by opening the second electrically driven valve for a certain period of time at the start of the cooling operation. Refrigerant can flow into the refrigerant flow path from the vessel via the first bypass flow path

  As described above, at the start of the cooling operation, it is possible to prevent the refrigerant from flowing backward from the refrigerant channel to the refrigerant regulator via the first bypass channel, and it is possible to prevent a shortage of the refrigerant in the refrigerant channel during the cooling operation. And the abnormal stop by the action | operation of a low-pressure protection apparatus or the freezing of a water heat exchanger by the refrigerant | coolant shortage in a refrigerant | coolant flow path can be prevented.

  In one embodiment, a check valve is provided in the first bypass channel between both ends of the third bypass channel to allow the refrigerant to flow in one direction from the refrigerant regulator to the refrigerant channel. ing.

  According to the refrigeration apparatus of this embodiment, the first bypass flow path is provided with the check valve that allows the refrigerant to flow in one direction from the refrigerant regulator to the refrigerant flow path. By closing the electric drive valve and opening the second electric drive valve for a fixed time at the start of the cooling operation, the refrigerant flows back from the refrigerant flow path to the refrigerant regulator via the first bypass flow path during the cooling operation. Can be surely prevented.

In one embodiment of the refrigeration apparatus,
The controller may, at the time of warm bunch operation, opening the first electrical drive valve, closes the second electrical drive valve.

According to the refrigeration apparatus of this embodiment, the control unit, during warm bunch operation, opening the first electrical driving valve, since closing the second electrical drive valve, during warm bunch operation, in the refrigerant flow path Excess refrigerant can be reliably returned to the refrigerant regulator.

  According to the refrigeration apparatus of the present invention, the compressor, the air heat exchanger, the expansion mechanism, the water heat exchanger, the switching valve, the refrigerant regulator, the first electric drive valve, and the second electric valve. Since the drive valve is provided, it is possible to prevent a refrigerant shortage in the refrigerant flow path during the cooling operation.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

  FIG. 1 shows a simplified configuration diagram as an embodiment of the refrigeration apparatus of the present invention. This refrigeration apparatus includes a compressor 1, an air heat exchanger 2, an expansion valve 3 (as an expansion mechanism), and a water heat exchanger 4.

  The compressor 1, the air heat exchanger 2, the expansion valve 3, and the water heat exchanger 4 are sequentially connected in an annular manner via a refrigerant flow path 10.

  The air heat exchanger 2 is provided with a fan, and performs heat exchange with air sent by the fan. The water heat exchanger 4 is provided with a water pipe, and performs heat exchange with water flowing through the water pipe.

  The refrigerant flow path 10 is provided with a four-way valve 5 (as a switching valve), and the four-way valve 5 changes the refrigerant flow during the cooling operation and the heating operation.

  One end of a first bypass channel 11 is connected to the refrigerant channel 10 between the expansion valve 3 and the water heat exchanger 4, and the refrigerant regulator 6 is connected to the other end of the first bypass channel 11. It is connected.

  One end of the second bypass passage 12 is connected to the refrigerant passage 10 between the air heat exchanger 2 and the expansion valve 3, and the refrigerant regulator 6 is connected to the other end of the second bypass passage 12. Is connected.

  Both ends of the third bypass channel 13 are connected to the first bypass channel 11. A first electromagnetic valve 21 (as a first electrically driven valve) is provided in the third bypass flow path 13. A second electromagnetic valve 22 (as a second electrically driven valve) is provided in the second bypass flow path 12.

  A check valve 23 is provided in the first bypass flow path 11 between both ends of the third bypass flow path 13, and the check valve 23 extends in one direction from the refrigerant regulator 6 to the refrigerant flow path 10. Pour refrigerant.

  A control unit 30 electrically connected to the first electromagnetic valve 21 and the second electromagnetic valve 22 is provided.

  The refrigerant flow of this refrigeration apparatus will be described. During the cooling operation, the refrigerant compressed by the compressor 1 is in order of the four-way valve 5, the air heat exchanger 2, the expansion valve 3, and the water as indicated by the solid line arrows. It returns to the compressor 1 through the heat exchanger 4. At this time, the air heat exchanger 2 serves as a condenser, and the water heat exchanger 4 serves as an evaporator.

  On the other hand, at the time of heating operation, as indicated by the dotted arrow, the refrigerant compressed by the compressor 1 sequentially passes through the four-way valve 5, the water heat exchanger 4, the expansion valve 3, and the air heat exchanger 2. Return to the compressor 1. At this time, the air heat exchanger 2 becomes an evaporator, and the water heat exchanger 4 becomes a condenser.

  Here, when the amount of refrigerant necessary for the refrigerant flow path 10 is compared between the cooling operation and the heating operation, the water heat exchanger 4 is more efficient in condensing the refrigerant than the air heat exchanger 2, and thus the cooling operation. The amount of refrigerant required for the refrigerant flow path 10 is smaller during the heating operation than at the time.

  And the said control part 30 closes the 1st electromagnetic valve 21 at the time of air_conditionaing | cooling operation, and opens the 2nd electromagnetic valve 22 only for the fixed time at the time of air_conditioning | cooling operation start, while opening the 1st electromagnetic valve 21 at the time of heating operation, The second electromagnetic valve 22 is closed.

  For this reason, during the heating operation, surplus refrigerant liquid flows into the refrigerant regulator 6 through the first bypass flow path 11 and the third bypass flow path 13 (first electromagnetic valve 21) and is stored. .

  On the other hand, during the cooling operation, since the amount of refrigerant necessary for the refrigerant flow path 10 is insufficient, the refrigerant liquid of the refrigerant regulator 6 passes through the first bypass flow path 11 (check valve 23) and passes through the refrigerant flow path 10. To make up for the shortage.

  At this time, the water temperature in the water heat exchanger 4 is relatively high, the internal pressure of the first bypass passage 11 is high, the internal temperature of the refrigerant regulator 6 is low because the outside air is low temperature, and the internal pressure of the refrigerant regulator 6 is low. Even if the cooling operation is performed in a state where the internal pressure of the first bypass passage 11 is lower, the internal pressure of the refrigerant regulator 6 is reduced by opening the second electromagnetic valve 22 for a certain period of time at the start of the cooling operation. The internal pressure of the first bypass passage 11 can be made higher, and the refrigerant can flow into the refrigerant passage 10 from the refrigerant regulator 6 via the first bypass passage 11.

  Thus, at the start of the cooling operation, it is possible to prevent the refrigerant from flowing back from the refrigerant flow channel 10 to the refrigerant regulator 6 via the first bypass flow channel 11, and the refrigerant shortage in the refrigerant flow channel 10 during the cooling operation can be prevented. Can be prevented.

  The fixed time for opening the second electromagnetic valve 22 is determined only by the time required to return the refrigerant accumulated in the refrigerant regulator 6 under the condition that the highest differential pressure is the smallest in the operating range. There is no need to detect and control operating conditions.

  According to the refrigeration apparatus having the above configuration, the compressor 1, the air heat exchanger 2, the expansion valve 3, the water heat exchanger 4, the four-way valve 5, the refrigerant regulator 6, and the first electromagnetic valve 21. In addition, since the second electromagnetic valve 22 is provided, even if the cooling operation is performed in a state where the internal pressure of the refrigerant regulator 6 is lower than the internal pressure of the first bypass passage 11, a certain time at the start of the cooling operation is obtained. Only by opening the second electromagnetic valve 22, the internal pressure of the refrigerant regulator 6 can be made higher than the internal pressure of the first bypass channel 11, and the refrigerant channel from the refrigerant regulator 6 through the first bypass channel 11. The refrigerant can flow into 10.

  Therefore, the refrigerant shortage in the refrigerant flow path 10 during the cooling operation can be prevented. And the abnormal stop by the action | operation of a low-pressure protective device or the freezing of the water heat exchanger 4 by the refrigerant | coolant shortage in the refrigerant | coolant flow path 10 can be prevented. Further, it is possible to operate stably at a relatively low cost and in the entire operation range without affecting the performance of the refrigeration apparatus.

  In addition, since the check valve 23 is provided, the first electromagnetic valve 21 is closed during the cooling operation, and the second electromagnetic valve 22 is opened for a certain period of time at the start of the cooling operation. Therefore, it is possible to reliably prevent the refrigerant from flowing back to the refrigerant regulator 6 through the first bypass flow path 11.

  In addition, since the control unit 30 is included, it is possible to reliably prevent the refrigerant from flowing backward from the refrigerant flow path 10 to the refrigerant regulator 6 via the first bypass flow path 11 during the cooling operation, Excess refrigerant in the flow path 10 can be reliably returned to the refrigerant regulator 6.

  In addition, this invention is not limited to the above-mentioned embodiment. For example, the check valve 23 may not be provided. In addition to the expansion valve 3, the expansion mechanism may be a capillary tube. In addition to the four-way valve 5, other valves may be used as the switching valve. In addition to the electromagnetic valves 21 and 22, an electrically driven valve may be an electric valve.

It is a simplified lineblock diagram showing one embodiment of the refrigerating device of the present invention. It is a simplified block diagram which shows the conventional freezing apparatus.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Air heat exchanger 3 Expansion valve (expansion mechanism)
4 Water heat exchanger 5 Four-way valve (switching valve)
6 Refrigerant regulator 10 Refrigerant flow path 11 First bypass flow path 12 Second bypass flow path 13 Third bypass flow path 21 First electromagnetic valve (first electrically driven valve)
22 Second solenoid valve (second electrically driven valve)
23 Check valve 30 Control unit

Claims (3)

A compressor (1), an air heat exchanger (2), an expansion mechanism (3), and a water heat exchanger (4);
The compressor (1), the air heat exchanger (2), the expansion mechanism (3), and the water heat exchanger (4) are sequentially connected in an annular manner via the refrigerant flow path (10),
The refrigerant flow path (10) is provided with a switching valve (5) that changes the flow of the refrigerant during the cooling operation and the heating operation,
One end of the first bypass channel (11) is connected to the refrigerant channel (10) between the expansion mechanism (3) and the water heat exchanger (4), and the first bypass channel (11). The refrigerant regulator (6) is connected to the other end of the
One end of a second bypass channel (12) is connected to the refrigerant channel (10) between the air heat exchanger (2) and the expansion mechanism (3), and the second bypass channel (12). The refrigerant regulator (6) is connected to the other end of the
Both ends of the third bypass channel (13) are connected to the first bypass channel (11),
A first electrically driven valve (21) is provided in the third bypass channel (13),
The second bypass flow path (12) is provided with a second electrically driven valve (22) ,
A control unit (30) electrically connected to the first electric drive valve (21) and the second electric drive valve (22);
The control unit (30) is characterized in that the first electric drive valve (21) is closed during cooling operation, and the second electric drive valve (22) is opened for a certain period of time when the cooling operation is started. Refrigeration equipment. The refrigeration apparatus according to claim 1,
A check valve that allows the refrigerant to flow in one direction from the refrigerant regulator (6) to the refrigerant flow path (10) into the first bypass flow path (11) between both ends of the third bypass flow path (13). 23) is provided. The refrigeration apparatus according to claim 1 or 2,
The control unit (30), during warm bunch operation, the first open electric driving valve (21), refrigeration system, characterized in that closing said second electrical drive valve (22).

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