JP2004198088A - Gas heat pump system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To safely stop operation of a system even when there is an abnormal high pressure in a compressor interior, and a high pressure pressure sensor does not operate normally. <P>SOLUTION: The system is composed so that the high pressure pressure sensor 22 detecting a pressure of a discharged medium is provided in a midway part of a discharge piping 18 connecting a compressor 12 and a condenser 13, a relief valve 40 with a working pressure higher than a set pressure of the high pressure pressure sensor 22 is attached to a second discharge port 12b of the compressor 12, and a high pressure refrigerant passage 24 connected to the relief valve 40 is connected to an accumulator 16. When the relief valve 40 is operated, its mechanical movement is converted into an electric signal and outputted to an air conditioner CPU, and an electromagnetic clutch 12-2 is turned off to stop operation of the system. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a gas heat pump system used as an indoor air conditioning system.
[0002]
[Prior art]
As a configuration example of a conventional gas heat pump system, for example, a configuration disclosed in Patent Document 1 below is known.
[0003]
[Patent Document 1]
JP-A-7-198220
[0004]
In the system of Patent Document 1, a refrigeration cycle including a compressor, a condenser, a receiver, a supercooler, an expansion valve, an evaporator, and an accumulator driven by a sub-engine is connected by piping, and each functions as follows.
[0005]
The compressor is driven by the sub-engine and compresses the refrigerant flowing in the refrigeration cycle to discharge high-temperature and high-pressure refrigerant. The condenser condenses the high-temperature and high-pressure refrigerant flowing from the compressor by exchanging heat with the outside air. The receiver stores the refrigerant flowing from the condenser, and allows only the liquid refrigerant to flow into the super cooler. The supercooler supercools the high-pressure liquid refrigerant flowing from the receiver. The expansion valve decompresses the high-pressure liquid refrigerant that has flowed in from the supercooler, and converts it into a low-temperature, low-pressure mist-like refrigerant. The evaporator exchanges heat between the low-temperature and low-pressure refrigerant flowing from the expansion valve and the outside air to cool the outside air, and turns the refrigerant into a gaseous refrigerant. The accumulator separates the gaseous refrigerant from the evaporator into two gas-liquid layers.
[0006]
The high-temperature and high-pressure refrigerant discharged from the compressor in this way repeats a cycle of radiating heat by the condenser and the super cooler, reducing the pressure by the expansion valve, absorbing heat by the evaporator, and returning to the compressor via the accumulator.
[0007]
By the way, in such a system, a temperature sensor and a high-pressure sensor are usually installed on the discharge side of the compressor in case the refrigerant inside the compressor has an abnormally high pressure. When the abnormal high pressure of the compressed refrigerant is detected by the high pressure sensor, the operation of the system is forcibly stopped.
[0008]
However, when the system is operated for a long time, the high-pressure sensor does not always operate normally, and sometimes an abnormally high pressure inside the compressor cannot be detected. The possible causes are as follows.
[0009]
Generally, in such a system, foreign matters such as copper chips and brazing generated at the time of welding pipes or aluminum powder generated by vane abrasion during compressor operation are mixed with the refrigerant and circulated in the piping of the system. On the other hand, in front of the high pressure sensor, a capillary tube having an inner diameter smaller than the inner diameter of the pipe is provided. The reason is that the pressure pulsation of the refrigerant discharged from the compressor is directly transmitted from the pipe to the high-pressure pressure sensor, preventing malfunction and failure of the high-pressure pressure sensor. This is for transmitting to the sensor and detecting that the average pressure of the refrigerant has become abnormally high. Since the capillary tube having a small inner diameter is disposed in front of the high-pressure sensor as described above, foreign matter circulating in the pipe is likely to be clogged in the capillary tube. This foreign matter cannot be removed unless the capillary tube is removed from the system, and if the system continues to operate with the foreign matter clogged, the refrigerant pressure reaching the high-pressure pressure sensor from the capillary tube reaches the normal value. Therefore, the abnormal high pressure of the refrigerant discharged from the compressor cannot be detected. In addition, the high pressure sensor is less likely to operate normally than the temperature sensor.
[0010]
On the other hand, in order to solve such a problem, it is conceivable to add a relief valve to the discharge side of the compressor at the time of abnormally high pressure in the compressor, but in this case, the refrigerant inside the compressor is discharged from the relief valve to the atmosphere. This is not preferable from the viewpoint of environmental problems.
[0011]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described problems, and has as its object to operate the system even when abnormal high pressure occurs inside the compressor and the high-pressure pressure sensor does not operate normally. The present invention is to provide a highly reliable gas heat pump system that can safely stop the operation of a high-pressure pressure sensor and can reliably determine the cause of a malfunction of a high-pressure pressure sensor.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a gas heat pump system according to the present invention is driven by a gas engine, sucks, compresses, and discharges a refrigerant, and heat-exchanges a high-temperature and high-pressure refrigerant discharged from the compressor with outside air. A condenser that condenses and liquefies, an expansion valve that depressurizes the refrigerant liquefied by the condenser, an evaporator that heat-exchanges the liquid refrigerant depressurized by the expansion valve with the outside air, and separates the refrigerant from the evaporator into two gas-liquid layers An accumulator that stores liquid refrigerant and sends only gas refrigerant to the compressor; a refrigerant pressure detection unit that is provided between the compressor and the condenser and detects a pressure of the refrigerant discharged from the compressor; and a refrigerant that is discharged from the compressor. Accumulate refrigerant when the pressure exceeds a predetermined pressure Characterized by comprising a refrigerant releasing means for releasing sent to over data, the.
[0013]
In the gas heat pump system of the present invention, the refrigerant release means includes a relief valve provided in the compressor and opened only when a predetermined pressure of the refrigerant discharged from the compressor is exceeded, and a high-pressure refrigerant passage connecting the relief valve and the accumulator. It is characterized by.
[0014]
In this gas heat pump system, it is preferable that the refrigerant release unit further includes a system stop unit that stops the operation of the system when the refrigerant passes through the high-pressure refrigerant passage.
[0015]
Various examples of the configuration of the system stop unit are conceivable. For example, a valve operation detection unit that detects the operation state of the relief valve is provided, and the operation of the relief valve detected by the valve operation detection unit is converted into an electric signal and converted. A configuration for outputting an electric signal to the CPU of the system is conceivable.
[0016]
Further, as another configuration example of the system stop unit, a refrigerant temperature detecting unit that detects a temperature change in the high-pressure refrigerant passage is provided, and the temperature change of the refrigerant detected by the refrigerant temperature detecting unit is converted into an electric signal and converted. A configuration for outputting an electric signal to the CPU of the system is also conceivable.
[0017]
Preferably, a manual valve for opening and closing the passage to the refrigerant pressure detecting means is provided, and the refrigerant pressure means is configured to be detachable from the system.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0019]
[First Embodiment]
FIG. 1 is a schematic diagram showing the entire configuration of the gas heat pump system according to the first embodiment.
[0020]
The gas heat pump system of the present embodiment includes an outdoor unit and an indoor unit, and the outdoor unit includes a gas engine 11, a compressor 12, a condenser 13, an expansion valve 14, and an accumulator 16, and the indoor unit is It is roughly configured with an evaporator 15.
[0021]
The compressor 12 has a function of sucking, compressing, and discharging the refrigerant, has a refrigerant compression mechanism (not shown) inside the main body, and has a suction port 12c for sucking the refrigerant from outside the main body, and discharges the refrigerant to the outside of the main body. It has two discharge ports, a first discharge port 12a and a second discharge port 12b. The compressor 12 is driven by the gas engine 11, compresses the refrigerant drawn from the suction port 12c by a refrigerant compression mechanism, and discharges the compressed high-temperature and high-pressure refrigerant from the first discharge port 12a.
[0022]
The condenser 13 has a function of condensing the refrigerant, and is disposed on the discharge side of the compressor 12. The condenser 13 and the first discharge port 12 a of the compressor 12 are connected by a discharge pipe 18 via a four-way valve 17. . The condenser 13 exchanges heat with high-temperature and high-pressure refrigerant discharged from the compressor 12 with outside air to condense and liquefy.
[0023]
The expansion valve 14 has a function of reducing the pressure of the refrigerant, and is connected to a downstream side of the condenser 13 by a pipe 20. The expansion valve 14 injects high-pressure refrigerant liquefied by the condenser 13 through minute nozzle holes to reduce the pressure.
[0024]
The evaporator 15 has a function of evaporating the liquid refrigerant, and is connected to the downstream side of the expansion valve 14 by a pipe 20. Further, the evaporator 15 is disposed on the suction side of the compressor 12, and the evaporator 15 and the suction port 12 c of the compressor 12 are connected by a suction pipe 19 via a four-way valve 17. The evaporator 15 heat-exchanges the low-temperature and low-pressure liquid refrigerant decompressed by the expansion valve 14 with the outside air to evaporate and cool the outside air.
[0025]
The accumulator 16 has a function of separating the refrigerant, and is provided in the middle of a suction pipe 19 connecting the suction port 12 c of the compressor 12 and the four-way valve 17. The accumulator 16 separates the refrigerant from the evaporator 15 into two layers of gas and liquid, stores the liquid refrigerant, and sends out only the gas refrigerant to the compressor 12.
[0026]
Although FIG. 1 illustrates the flow of the refrigerant during cooling in this system, the refrigerant is liquefied by switching the four-way valve 17 to reverse the flow of the refrigerant and causing the evaporator 15 of the indoor unit to function as a condenser. It is possible to heat the room with the heat generated when the heat is generated.
[0027]
A temperature sensor 21 is installed in the discharge pipe 18 connecting the compressor 12 and the four-way valve 17. The temperature sensor 21 detects the temperature of the refrigerant discharged from the compressor 12 and monitors the refrigerant, which has reached an abnormally high temperature, so as not to flow out to the condenser 13 at the subsequent stage to reduce the heat exchange efficiency.
[0028]
A pressure sensor 23 is installed in the suction pipe 19 connecting the compressor 12 and the accumulator 16. The pressure sensor 23 detects the pressure of the refrigerant sucked into the compressor 12, and monitors the refrigerant so as to prevent the refrigerant having an abnormally high pressure from flowing into the compressor 12 and lowering the compression ratio.
[0029]
In addition, the system includes a refrigerant pressure detecting unit that detects a pressure of the refrigerant discharged from the compressor 12 in consideration of a case where a pressure of the refrigerant discharged from the compressor 12 becomes abnormally high, and a refrigerant pressure detecting unit. And a refrigerant releasing means for releasing the refrigerant which has become abnormally high pressure when the device does not operate normally.
[0030]
First, details of the refrigerant pressure detecting means will be described with reference to FIG. FIG. 2 shows a configuration in the vicinity of the high-pressure sensor, and is an enlarged sectional view of the vicinity of the portion A in FIG.
[0031]
In the present embodiment, the refrigerant pressure detecting means is constituted by a high pressure sensor 22. The high pressure sensor 22 is disposed in the middle of a discharge pipe 18 connecting the first discharge port 12 a of the compressor 12 and the four-way valve 17. I have.
[0032]
When the vicinity of the high-pressure sensor 22 is enlarged, the discharge pipe 18 is composed of a main flow path 18-1 communicating with the condenser 13 at the subsequent stage, and a sub flow path 18-2 branched from the main flow path 18-1. A high pressure sensor 22 is connected to the tip of the sub flow path 18-2 via a capillary tube 18-3. The high pressure sensor 22 and the capillary tube 18-3 are attached to and detached from the sub flow path 18-2. It is configured to be possible. The capillary tube 18-3 prevents the pressure pulsation of the refrigerant discharged from the compressor 12 from being directly transmitted from the sub flow path 18-2 to the high-pressure pressure sensor 22, and averages and transmits the refrigerant pressure. The pressure sensor 22 plays a role of enabling normal detection of an abnormally high pressure of the refrigerant.
[0033]
The sub flow path 18-2 is provided with a manual valve 31 and a charge valve 32 for performing evacuation from the near side along the flow of the refrigerant. The manual valve 31 can supply or shut off the refrigerant from the main flow path 18-1 to the sub flow path 18-2.
[0034]
When the manual valve 31 is closed, the passage between the main flow path 18-1 and the sub flow path 18-2 is shut off, and the refrigerant in the system piping is not supplied to the high pressure sensor 22. When the manual valve 31 is opened, the passage between the main flow path 18-1 and the sub flow path 18-2 communicates, and the refrigerant in the system piping is supplied to the high pressure sensor 22 via the capillary tube 18-3.
[0035]
Note that when performing vacuum evacuation described below, a charge hose is connected to the charge valve 32, and a vacuum pump (not shown) is connected to the charge hose.
[0036]
Next, details of the refrigerant release means will be described with reference to FIGS. FIG. 3 is an enlarged plan view showing the configuration of the compressor, and FIG. 4 is an enlarged sectional view showing the configuration of the relief valve.
[0037]
As shown in FIG. 3, two discharge ports, a first discharge port 12a and a second discharge port 12b, are provided on the discharge side of the compressor 12.
[0038]
The first discharge port 12a is connected to the discharge pipe 18 connected to the condenser 13 as described above.
[0039]
The second discharge port 12b is higher than the set pressure of the high pressure sensor 22 so that the high pressure sensor 22 does not operate and opens only when the pressure of the refrigerant discharged from the compressor 12 exceeds a predetermined pressure. A relief valve 40 for which an operating pressure is set is mounted. Further, a pipe connected to the second discharge port 12b via the relief valve 40 is connected to the accumulator 16 to form the high-pressure refrigerant passage 24.
[0040]
Here, the reason why the high-pressure refrigerant passage 24 is connected to the accumulator 16 is as follows.
[0041]
In order to generate the flow of the refrigerant having an abnormally high pressure, the connection destination needs to be on the low pressure side. Opening to the accumulator 16 having a larger capacity than the suction pipe 19 especially on the low pressure side enables the compressor 12 to suck the refrigerant by reducing the pressure of the high pressure refrigerant. Further, if the compressor 12 is directly connected to the low-pressure side suction pipe 19, the refrigerant passing through the high-pressure refrigerant passage 24 is sucked into the compressor 12 at a high pressure and discharged since the compressor 12 is still operating. It is not preferable because the abnormally high pressure of the refrigerant is increased.
[0042]
For this reason, the relief valve 40 is connected to the accumulator 16 via the high-pressure refrigerant passage 24, and even if the relief valve 40 is operated and the second discharge port 12b of the compressor 12 is opened, the inside of the compressor 12 The high-pressure refrigerant returns to the accumulator 16 via the high-pressure refrigerant passage 24 without being released to the atmosphere. Therefore, it is possible to keep the refrigerant in the piping of the system, and it is not necessary to charge the refrigerant again at the time of re-operation.
[0043]
More specifically, as shown in FIG. 4, the relief valve 40 of the present embodiment has a structure capable of detecting a mechanical operation of the valve, converting the mechanical operation into an electric signal, and outputting the electric signal to a CPU (not shown) of the system. Has been adopted.
[0044]
In the relief valve 40, a first valve plate 42 and a second valve plate 43 made of a conductive material are seated on the bottom surface of a cylindrical valve case 41 made of an insulator, and a sealing member is provided between the two valve plates 42, 43. A packing as 44 is inserted.
[0045]
The first valve plate 42 has a communication hole 42a communicating with the second discharge port 12b, and a ring-shaped convex portion 42b protrudes around the communication hole 42a.
[0046]
The second valve plate 43 has a ring-shaped concave portion 43b fitted to the convex portion 42b, and is urged downward by the spring force of the compression spring 45. Lead wires 46, 46 are respectively connected to the first valve plate 42 and the second valve plate 43, and the lead wires 46, 46 are electrically connected to the air conditioner CPU.
[0047]
According to the relief valve 40 configured as described above, when the refrigerant in the compressor 12 has a predetermined pressure, as shown in FIG. 4A, the refrigerant is urged by the spring force of the compression spring 45, and the first valve plate 42 Is in contact with the concave portion 43b of the second valve plate 43, and the valve is closed. Therefore, the lead wires 46, 46 are energized, power is supplied to the air conditioner CPU, and the operation of the system is continued.
[0048]
On the other hand, when the refrigerant in the compressor 12 has an abnormally high pressure, the second valve plate 43 is lifted by the pressure of the high-pressure refrigerant against the spring force of the compression spring 45, as shown in FIG. The convex portion 42b of the plate 42 and the concave portion 43b of the second valve plate 43 become out of contact with each other, and the valve is opened. Therefore, the power supply to the lead wires 46, 46 is cut off, no power is supplied to the air conditioner CPU, the electromagnetic clutch 12-2 is turned off, and the operation of the system is forcibly stopped.
[0049]
Next, the operation of the gas heat pump system according to the present embodiment will be described in detail with reference to the flowchart from the occurrence of abnormally high pressure to the restart shown in FIG.
[0050]
If an abnormally high pressure is generated in the compressor case 12-1 (step 501), the high-pressure refrigerant discharged from the first discharge port 12a normally flows through the discharge pipe 18 through the sub flow path 18-2. , Sequentially pass through the capillary tube 18-3, reach the high pressure sensor 22, and the high pressure sensor 22 operates (YES in step 502).
[0051]
When the high pressure sensor 22 is activated, a system error message is displayed to the operator (step 515). As the display content, a cause for stopping the system, such as “high pressure abnormality”, is displayed. On the other hand, when the high pressure sensor 22 operates, the electromagnetic clutch 12-2 is turned off (step 516), the transmission of power from the gas engine 11 to the compressor 12 is interrupted, the operation of the compressor 12 stops, and the system stops ( Step 517).
[0052]
On the other hand, in the case of an abnormal situation in which the high-pressure sensor 22 does not operate due to some cause, for example, clogging of the capillary tube 18-3 or failure of the high-pressure sensor 22 (NO in step 502), the relief valve 40 is operated as described with reference to FIG. It operates (step 503).
[0053]
When the relief valve 40 is operated, a system error message is displayed to the operator (step 504). As the display content, a cause for stopping the system, such as “high pressure abnormality”, is displayed. Note that the error message here is different from the error message in step 515 in that the cause of the system stop is different from that in the case of the error message in step 515. It is preferable to display and distinguish that an abnormal situation in which the operation of the engine 22 does not work.
[0054]
On the other hand, when the relief valve 40 is operated, the convex portion 42b of the first valve plate 42 and the concave portion 43b of the second valve plate 43 become non-contact, and the power supply to the lead wires 46, 46 is cut off (step 505). Then, power is not supplied to the air conditioner CPU, and the electromagnetic clutch 12-2 is turned off (step 506).
[0055]
When the electromagnetic clutch 12-2 is turned off, the transmission of power from the gas engine 11 to the compressor 12 is interrupted, the operation of the compressor 12 stops, and the system stops (step 507).
[0056]
As a result of step 504 or step 515, the operator can confirm the reason why the system has stopped by looking at the display contents of the error message, and can recover the stopped system according to the following procedure.
[0057]
First, the manual valve 31 provided in front of the high pressure sensor 22 is closed (step 508), and the communication between the main flow path 18-1 and the sub flow path 18-2 of the discharge pipe 18 is cut off. Prevent the refrigerant from leaking to the outside.
[0058]
Next, the high pressure sensor 22 causing the system stop is removed (step 509), and a new high pressure sensor 22 is attached instead (step 510). After the high pressure sensor 22 is attached, a charge hose is connected to the charge valve 32, and the inside of the system piping is evacuated using a vacuum pump connected to the charge hose (step 511).
[0059]
Then, the closed manual valve 31 is opened (step 512), and the communication between the main flow path 18-1 and the sub flow path 18-2 that has been shut off is restored. The flow path of the refrigerant flowing to the high-pressure sensor 22 via 3 is secured.
[0060]
Finally, the system can be restarted (step 514) by pressing the reset button to release the system error message (step 513).
[0061]
As described above, the high-pressure pressure sensor 22 in question can be removed from the system while preventing the refrigerant from leaking from the piping to the outside of the system, so that the removed high-pressure pressure sensor 22 and the capillary tube 18-3 can be precisely connected. Can be inspected. Therefore, the reason why the system is stopped due to the operation of the relief valve 40 without the normal operation of the high-pressure pressure sensor 22 is the failure of the high-pressure pressure sensor 22, or the failure is not caused by the foreign matter in the capillary tube 18-3. Can be ascertained as to whether or not it is due to clogging. At this time, the operator can confirm whether the direct cause of the system stop is the operation of the high-pressure pressure sensor 22 or the operation of the relief valve 40 by looking at the display content of the error message. Shortening can be achieved.
[0062]
[Second embodiment]
Various examples of the configuration of the system stopping means for stopping the operation of the system when the refrigerant has passed through the high-pressure refrigerant passage 24 are conceivable. For example, a configuration as shown in FIG. 6 may be employed. FIG. 6 is an enlarged plan view showing another configuration example of the compressor. Note that the basic configuration of the gas heat pump system according to the present embodiment is the same as that of the first embodiment, and a detailed description thereof will be omitted.
[0063]
As in the first embodiment, a relief valve 40 is mounted on a second discharge port 12b provided on the discharge side of the compressor 12, and a pipe connected to the second discharge port 12b via the relief valve 40. Are connected to the accumulator 16 to form a high-pressure refrigerant passage 24.
[0064]
In the present embodiment, a structure in which the temperature sensor 50 is attached to the outside of the pipe immediately after the relief valve 40 is employed. The temperature sensor 50 is an example of a temperature detection method that functions as a system stop unit that stops the operation of the compressor 12 in an abnormal situation in which the relief valve 40 operates.
[0065]
The temperature sensor 50 contacts the pipe and detects the temperature inside the high-pressure refrigerant passage 24. When the high-pressure refrigerant inside the compressor 12 is discharged by operating the relief valve 40, the high-pressure refrigerant passes through the high-pressure refrigerant passage 24. At this time, the temperature inside the high-pressure refrigerant passage 24 rises from a normal ambient temperature due to the temperature of the high-pressure refrigerant and becomes high. When the temperature sensor 50 detects this temperature change, it converts it into an electric signal, and the converted electric signal is output via a lead wire 51 to an air conditioner CPU (not shown) for controlling the system.
[0066]
Therefore, if the air conditioner CPU is provided with a control circuit that turns off the electromagnetic clutch 12-2 that transmits the drive of the gas engine 11 when the electric signal is input, an abnormal situation in which the relief valve 40 operates may occur. Then, the compressor 12 stops, and the operation of the system can be stopped immediately.
[0067]
In addition, there are a contact type and a non-contact type temperature sensor. Here, a contact type temperature sensor is used because the temperature in the passage is measured by contacting the pipe. For example, a thermistor, a thermocouple, a platinum A resistance thermometer can be used. Further, as such a system stop unit for detecting the temperature of the refrigerant, a thermal protector may be used instead of the temperature sensor.
[0068]
Next, the operation of the gas heat pump system according to the second embodiment will be described in detail with reference to the flowchart from the occurrence of abnormally high pressure to the restart shown in FIG.
[0069]
If an abnormally high pressure is generated in the compressor case 12-1 (step 701), normally, the high-pressure refrigerant discharged from the first discharge port 12a passes through the discharge pipe 18 and passes through the sub flow path 18-2. , Sequentially pass through the capillary tube 18-3 to reach the high pressure sensor 22, and the high pressure sensor 22 is activated (YES in step 702).
[0070]
When the high pressure sensor 22 is activated, a system error message is displayed to the operator (step 715). As the display content, a cause for stopping the system, such as “high pressure abnormality”, is displayed. On the other hand, when the high pressure sensor 22 operates, the electromagnetic clutch 12-2 is turned off (step 716), the transmission of power from the gas engine 11 to the compressor 12 is cut off, the operation of the compressor 12 is stopped, and the system is stopped ( Step 717).
[0071]
On the other hand, in the case of an abnormal situation in which the high-pressure sensor 22 does not operate due to any cause, for example, clogging of the capillary tube 18-3 or failure of the high-pressure sensor 22 (NO in step 702), the relief valve 40 is operated in the manner described with reference to FIG. It operates (step 703).
[0072]
When the relief valve 40 is actuated, a system error message is displayed to the operator (step 704). As the display content, a cause for stopping the system, such as “high pressure abnormality”, is displayed. Note that the error message here is different from the error message in step 715 in the direct cause of the system stop. For example, as in the case of “high pressure abnormality (relief valve operation)”, the cause of the system stop is the high pressure sensor. It is preferable to display and distinguish that an abnormal situation in which the 22 does not operate.
[0073]
On the other hand, when the pressure in the compressor 12 is compared with the pressure in the accumulator 16 when the relief valve 40 is operated, a higher pressure difference is generated in the compressor 12. For this reason, the refrigerant in the compressor 12 flows into the low-pressure accumulator 16 via the high-pressure refrigerant passage 24. At this time, since the high-temperature and high-pressure refrigerant passes through the high-pressure refrigerant passage 24, the temperature sensor 50 immediately after the relief valve 40 operates in the manner described with reference to FIG. 6 (step 705), and the electromagnetic clutch 12-2 is turned off. (Step 706).
[0074]
When the electromagnetic clutch 12-2 is turned off, the transmission of power from the gas engine 11 to the compressor 12 is interrupted, the operation of the compressor 12 stops, and the system stops (step 707).
[0075]
As a result of step 704 or step 715, the operator can confirm the reason why the system has stopped by looking at the display contents of the error message, and can recover the stopped system according to the following procedure.
[0076]
First, the manual valve 31 provided in front of the high pressure sensor 22 is closed (step 708), and the communication between the main flow path 18-1 and the sub flow path 18-2 of the discharge pipe 18 is cut off. Prevent the refrigerant from leaking to the outside.
[0077]
Next, the high pressure sensor 22 causing the system stoppage is removed (step 709), and a new high pressure sensor 22 is attached instead (step 710). After the high pressure sensor 22 is attached, a charge hose is connected to the charge valve 32, and the inside of the system piping is evacuated using a vacuum pump connected to the charge hose (step 711).
[0078]
Then, the closed manual valve 31 is opened (step 712), and when the communication between the closed main flow path 18-1 and the sub flow path 18-2 is restored, the capillary tube 18- is moved from the sub flow path 18-2. The flow path of the refrigerant flowing to the high-pressure sensor 22 via 3 is secured.
[0079]
Finally, the system can be restarted (step 714) by pressing the reset button to release the system error message (step 713).
[0080]
As described above, also in the present embodiment, when an abnormally high pressure occurs, the operation of the system is stopped, and the stopped system can be restarted. Therefore, the same effects as those in the first embodiment described above are obtained.
[0081]
【The invention's effect】
As described in detail above, the gas heat pump system according to the present invention has the following effects.
[0082]
(1) Even when the high-pressure sensor does not operate normally due to a failure of the high-pressure sensor or clogging of the capillary tube, the relief valve operates and the operation of the system can be stopped safely.
[0083]
(2) Since the high-pressure refrigerant inside the compressor returns to the accumulator without being released to the atmosphere due to the operation of the relief valve, it is possible to keep the refrigerant in the piping of the system. There is no need to charge the refrigerant again.
[0084]
(3) Since the detached high-pressure sensor and capillary tube can be inspected precisely, it is possible to surely investigate the cause of the system stoppage due to the inoperative high-pressure sensor. At this time, the operator can confirm the direct cause of the system stop by looking at the display content of the error message, so that the work time until the system is restored can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an overall configuration of a gas heat pump system according to a first embodiment.
FIG. 2 is an enlarged cross-sectional view illustrating a configuration near a high-pressure sensor according to the first embodiment.
FIG. 3 is an enlarged plan view illustrating a configuration of a compressor according to the first embodiment.
FIG. 4 is an enlarged sectional view showing a configuration of a relief valve according to the first embodiment.
FIG. 5 is a flowchart illustrating an operation according to the first embodiment.
FIG. 6 is an enlarged plan view illustrating a configuration example of a compressor according to a second embodiment.
FIG. 7 is a flowchart for explaining the operation in the second embodiment.
[Explanation of symbols]
11 Gas engine
12 Compressor
12-1 Compressor case
12-2 Electromagnetic clutch
12a First discharge port
12b Second discharge port
12c suction port
13 Capacitor
14 Expansion valve
15 Evaporator
16 Accumulator
17 Four-way valve
18 Discharge piping
18-1 Main flow path
18-2 Sub flow path
18-3 Capillary tube
19 Suction piping
20 piping
21 Temperature sensor
22 High pressure sensor
23 Pressure sensor
24 High-pressure refrigerant passage
31 Manual valve
32 charge valve
40 relief valve
41 Valve case
42 1st valve plate
42a communication hole
42b convex part
43 2nd valve plate
43b recess
44 Sealing member
45 Compression spring
46 Lead wire
50 temperature sensor
51 Lead wire

Claims (6)

A compressor driven by a gas engine to suck, compress, and discharge refrigerant;
A condenser that exchanges heat and exchanges high-temperature and high-pressure refrigerant discharged from the compressor with outside air to condense and liquefy,
An expansion valve for reducing the pressure of the refrigerant liquefied by the condenser,
An evaporator that causes the liquid refrigerant decompressed by the expansion valve to exchange heat with outside air,
An accumulator that separates the refrigerant from the evaporator into two layers of gas and liquid, stores the liquid refrigerant, and sends only the gas refrigerant to the compressor.
Refrigerant pressure detection means provided between the compressor and the condenser, for detecting the pressure of the refrigerant discharged from the compressor,
When the pressure of the refrigerant discharged from the compressor exceeds a predetermined pressure, refrigerant releasing means for releasing and transmitting the refrigerant to the accumulator,
A gas heat pump system comprising: The refrigerant release means includes a relief valve provided in the compressor and opened only when a predetermined pressure of the refrigerant discharged from the compressor is exceeded, and a high-pressure refrigerant passage connecting the relief valve and the accumulator, The gas heat pump system according to claim 1. 3. The gas heat pump system according to claim 2, wherein the refrigerant release unit further includes a system stop unit that stops the operation of the system when the refrigerant passes through the high-pressure refrigerant passage. The system stopping means is provided with valve operation detecting means for detecting an operation state of the relief valve, converts the operation of the relief valve detected by the valve operation detecting means into an electric signal, and transmits the converted electric signal to the CPU of the system. The gas heat pump system according to claim 3, wherein the gas heat pump system outputs the output. The system stopping means is provided with a refrigerant temperature detecting means for detecting a temperature change in the high-pressure refrigerant passage, converts the temperature change of the refrigerant detected by the refrigerant temperature detecting means into an electric signal, and converts the converted electric signal into a system signal. 4. The gas heat pump system according to claim 3, wherein the signal is output to a CPU. The gas heat pump according to any one of claims 1 to 5, further comprising a manual valve for opening and closing a passage to the refrigerant pressure detection means, wherein the refrigerant pressure means is configured to be detachable from the system. system.

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