JP2014058931A - Cooling device for power generation source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device for a power generation source capable of detecting the shortage of a circulation amount of a cooling liquid without delay while lowering cost by eliminating a liquid level sensor.SOLUTION: A cooling device for a power generation source includes: a buffer tank 3 which stores a cooling liquid for cooling a power generation source comprising a gas engine generator 2 or a fuel cell; a cooling liquid circuit 4 which is arranged being in contact with the power generation source, which is formed by containing the buffer tank 3 and in which the cooling liquid flows; a circulation pump 5 which circulates the cooling liquid; a rotational speed sensor 55 which detects a rotation number N of the circulation pump 5; liquid temperature sensors 61 and 62 which detect temperatures T1 and T2 of the cooling liquid; and a monitoring control part 7 which monitors the rotation number N of the circulation pump and the temperatures T1 and T2 of the cooling liquid. The buffer tank 3 has a liquid outlet 31 from which the cooling liquid flows out to the cooling liquid circuit 4 at a liquid level position L2 of the time when the cooling liquid leaks to the limit of an allowable leakage amount. The monitoring control part 7 detects the shortage of a circulation amount of the cooling liquid on the basis of abnormality of at least one of the rotation number N of the circulation pump 5 and the temperatures T1 and T2 of the cooling liquid.

Description

  The present invention relates to a cooling device that includes a buffer tank and cools a gas engine generator or a fuel cell by circulating a coolant.

  In recent years, the diversification of power sources has been proposed, and the development and popularization of various types of distributed generators have been promoted. Initially, distributed generators were often applied to offices and apartment buildings. However, gas engine generators and fuel cells have been reduced in size and capacity, and are now also applied to ordinary households. It is coming. This type of distributed generator is often used as a cogeneration system that can use not only electrical output but also heat output. In this case, a cooling device having a cooling circuit, a circulation pump, and a liquid heat exchanger that circulates the cooling liquid is generally employed as an application that uses the heat output while cooling the power generation source. . Furthermore, in order to have a heat storage function for accumulating surplus heat when the heat load is relatively small with respect to the electrical load and a buffer function for suppressing the temperature rise of the coolant, the amount of the coolant is increased. It is stored in the buffer tank.

  The fuel cell system disclosed in Patent Document 1 is a technical example of a distributed power generator that can be used as a cogeneration system. This fuel cell system includes a first heat medium (cooling liquid) for extracting heat generated in the fuel cell to the outside, a first heat medium conveying means (circulation pump), and a temperature detector (liquid temperature sensor). The first heat medium conveying means is configured at a position lower than the temperature detector, and stops operation when the temperature of the first heat medium detected by the temperature detector is abnormal. According to this configuration, when the first heat medium is gradually reduced, the temperature detector is not filled with the first heat medium and a temperature abnormality occurs. Therefore, the first heat medium transporting unit removes the first heat medium. It is described that the operation can be stopped before the conveyance stops and the water level detector for determining the decrease in the first heat medium can be omitted.

JP 2010-287361 A

  By the way, in patent document 1, although the point which can reduce cost by omitting a water level detector (liquid level sensor) is preferable, there exists a possibility that determination of the temperature abnormality of a temperature detector may be overdue, and it may take time for a system stop. More specifically, the first heat medium conveying means performs normal conveyance (pump discharge) while the medium inlet is filled with the first heat medium even if the first heat medium gradually decreases. The first heat medium is pumped to the temperature detector in the middle of the flow path. Therefore, temperature abnormality does not occur immediately in the temperature detector. The temperature abnormality actually occurs after the air is mixed in the first heat medium and circulates. The first heat medium is reduced by a considerable amount, and the liquid level is the first heat medium conveying means. It is after dropping. Therefore, the timing for stopping the operation is delayed as compared with the configuration including the water level detector.

  As described above, when the liquid level sensor is omitted in order to reduce the cost, the problem that the detection of the insufficient circulation amount of the coolant is delayed is not limited to the fuel cell, but a gas engine having a similar cooling structure. The same applies to generators.

  The present invention has been made in view of the above-mentioned problems of the background art, and provides a cooling device for a power generation source that can detect a lack of circulation amount of a cooling liquid without delay while reducing the cost by omitting a liquid level sensor. This is a problem to be solved.

  The cooling device for a power generation source according to the present invention includes a buffer tank for storing a coolant for cooling a power generation source composed of a gas engine generator or a fuel cell, a buffer tank disposed in contact with the power generation source, and the buffer tank. A coolant circuit through which the coolant flows, a circulation pump that circulates the coolant in the coolant circuit, a rotation speed sensor that detects the number of rotations of the circulation pump, and a middle of the coolant circuit A liquid temperature sensor that detects the temperature of the coolant, and a monitoring controller that monitors the number of revolutions of the circulation pump and the temperature of the coolant, and the buffer tank allows the coolant to leak A liquid outlet through which the cooling liquid flows into the cooling liquid circuit at a liquid level when leaking to the limit of the amount; and the monitoring control unit is configured to reduce the number of rotations of the circulation pump and the temperature of the cooling liquid. Based at one of the abnormally Kutomo, it detects the shortage of the cooling liquid.

  Furthermore, it further includes a leak prevention pan that receives the coolant leaked from the buffer tank, the coolant circuit, and the circulation pump to prevent leakage to the outside, and the allowable leak amount of the coolant is equal to the leak prevention pan. It is preferable that it is determined based on the volume.

  In addition, the allowable leakage amount of the cooling liquid may be determined so that the cooling liquid maintains a liquid surface position higher than an intermediate height in the buffer tank.

  Furthermore, it is preferable that the buffer tank has a liquid inlet through which the cooling liquid flows from the cooling liquid circuit at a position lower than the liquid outlet.

  Furthermore, the coolant circuit has a bypass circuit that circulates the coolant without passing through the buffer tank, and a control valve that controls a ratio at which the coolant is divided into the buffer tank and the bypass circuit. It may be.

  The power generation source may be used in a cogeneration system that obtains an electrical output and a heat output, and the coolant circuit may be a circuit that obtains the heat output.

  In the cooling device for a power generation source according to the present invention, when the coolant leaks to the limit of the allowable leakage amount, the liquid level of the coolant in the buffer tank is lowered to the liquid outlet, and air is mixed into the coolant and circulated. become. For this reason, the load of the circulation pump is changed to cause an abnormality in the rotational speed, and the performance for cooling the power generation source is changed to cause an abnormality in the temperature of the coolant. Therefore, the monitoring control unit can detect the shortage of the circulating amount of the coolant based on at least one of the abnormality of the rotational speed of the circulation pump and the temperature of the coolant. In other words, even if the liquid level sensor is omitted and the cost is reduced, when the coolant leaks to the limit of the allowable leakage amount, it is possible to detect an insufficient circulation amount of the coolant without delay, and to quickly take measures for abnormal situations. .

  Furthermore, in the aspect provided with the leakage prevention pan, the allowable leakage amount of the cooling liquid is determined based on the volume of the leakage prevention pan, so that it is ensured that the amount of cooling liquid circulation is insufficient before the leaked cooling liquid starts to leak outside. It can be detected.

  Further, in an aspect in which the allowable leakage amount of the cooling liquid is set to maintain a liquid surface position higher than the intermediate height in the buffer tank, a minor stage of leakage in which the cooling liquid remains up to more than half of the buffer tank. Thus, it is possible to reliably detect an insufficient circulation amount of the coolant.

  Furthermore, in the aspect having the liquid inlet at a position lower than the liquid outlet of the buffer tank, the relatively warm coolant that has cooled the power generation source flows into the lower portion of the buffer tank and is mixed with the relatively cool coolant due to the density difference. Fit. Therefore, it becomes easy to make the temperature distribution of the coolant inside the buffer tank uniform and keep it at an appropriate temperature, and it is possible to eliminate the possibility that the relatively warm coolant is circulated to the power generation source and the cooling performance is lowered. If the liquid inlet is high, the relatively warm coolant flows into and stays in the upper part of the buffer tank, increasing the temperature difference between the top and bottom, and the warm coolant is circulated to the power generation source to prevent a sufficient cooling effect. There is a fear.

  Furthermore, in the aspect in which the coolant circuit has the bypass circuit and the control valve, the warm-up operation at the time of starting the power generation source can be made efficient. For example, when the power generation source is stopped for a long time, the coolant in the buffer tank and the coolant circuit is at a low temperature. In this case, at the next start-up, not all the coolant including the inside of the buffer tank is circulated, but only a part of the coolant in the coolant circuit is circulated using the bypass circuit. Thereby, the coolant can be quickly raised to an appropriate temperature, and the warm-up operation can be completed in a short time.

  Further, in the aspect in which the power generation source is used in the cogeneration system, for example, a heat output can be obtained from the coolant circuit using a heat exchanger. In this case, unlike a general cooling device, it cannot be said that the lower the liquid temperature of the cooling liquid, the better. From the viewpoint of utilization of heat output, it is preferable to keep the cooling liquid at an appropriate temperature. Therefore, the heat output can be efficiently achieved by applying the aspect having the liquid inlet at a position lower than the liquid outlet of the buffer tank described above or the aspect in which the above-described cooling liquid circuit has the bypass circuit and the control valve to the cogeneration system. Available to:

1 is an overall configuration diagram schematically illustrating a cooling device for a power generation source according to an embodiment of the present invention. It is a figure of the flowchart explaining the monitoring control flow of a monitoring control part. It is a figure which shows the flow of a cooling fluid in the cooling device of the power generation source of embodiment. It is a figure explaining operation | movement when a cooling fluid leaks to the limit of the allowable leakage amount in the cooling device of the power generation source of embodiment. It is a whole block diagram which illustrates typically the cooling device of the power generation source of a reference form.

  An embodiment for carrying out the present invention will be described with reference to FIGS. FIG. 1 is an overall configuration diagram schematically illustrating a power generation cooling device 1 according to an embodiment of the present invention. The cooling device 1 is a device that circulates coolant and cools the gas engine generator 2 that is a power generation source, and is used as a cogeneration system. The cooling device 1 includes a buffer tank 3, a coolant circuit 4, a circulation pump 5, a rotation speed sensor 55, an engine inlet liquid temperature sensor 61, an engine outlet liquid temperature sensor 62, a monitoring control unit 7, and the like.

  The buffer tank 3 is a tank that stores a coolant for cooling the gas engine generator 2. The buffer tank 3 has a liquid outlet 31 through which the cooling liquid flows out and a liquid inlet 32 through which the cooling liquid flows. As the coolant, for example, a long life coolant (symbol LLC) which is a kind of antifreeze liquid defined in JIS standards can be used. Long-life coolant is obtained by dissolving ethylene glycol in water to lower the freezing point, and does not freeze even when the ambient temperature drops to -30 ° C in cold regions in winter. However, the present invention is not limited to this, and other types of coolant may be used.

  The buffer tank 3 has a heat storage function for temporarily storing the heat output of the co-generation system when the heat load is relatively small with respect to the electric load. From another viewpoint, it has a buffer function that suppresses the temperature rise of the coolant due to excess heat. In order to realize the desired heat storage function and buffer function, the amount of the coolant stored in the buffer tank 3 is set appropriately.

  The coolant circuit 4 is a peripheral circuit that is disposed in contact with the gas engine generator 2 and includes the buffer tank 3 and flows through the coolant. The coolant circuit 4 includes an outward path portion 41 from the liquid outlet 31 of the buffer tank 3 until it contacts the gas engine generator 2, and a cooling operation portion 42 that contacts the high temperature portion of the gas engine generator 2 and exhibits a cooling effect (shown by broken lines). ), And a return path 43 extending from the gas engine generator 2 to the liquid inlet 32 of the buffer tank 3. The cooling action part 42 is a part called a cooling jacket or the like, and its structure is not particularly limited.

  The circulation pump 5 is provided in the middle of the forward path portion 41 of the coolant circuit 4. The suction port 51 of the circulation pump 5 is communicated with the liquid outlet 31 of the buffer tank 3, and the discharge port 52 is communicated with the inlet of the cooling action unit 42. As the circulation pump 5, a general pump that is rotationally driven by a drive motor can be used. The rotational speed N of the circulation pump 5 varies depending on the load weight. For example, when a part of the coolant circuit 4 is deformed for some reason and the flow passage cross-sectional area is reduced, the load becomes heavy and the rotational speed N is reduced. Further, for example, when air is mixed into the coolant, the load is reduced and the rotational speed N is increased.

  The rotation speed sensor 55 is a sensor that detects the rotation speed N of the circulation pump 5. The rotation speed sensor 55 can be, for example, a sensor of a type in which a magnet is attached to the rotating part and a change in the magnetic field is detected from the fixed part. The rotation speed sensor 55 transmits a signal of the detected rotation speed N to the monitoring controller 7.

  The engine inlet liquid temperature sensor 61 is disposed at a connection point between the forward path portion 41 and the cooling action portion 42 of the coolant circuit 4. The engine inlet liquid temperature sensor 61 detects a relatively low liquid temperature of the coolant immediately before flowing into the cooling operation section 42, that is, the engine inlet liquid temperature T 1, and transmits the signal to the monitoring control section 7. On the other hand, the engine outlet liquid temperature sensor 62 is disposed at a connection point between the cooling action section 42 and the return path section 43 of the coolant circuit 4. The engine outlet liquid temperature sensor 62 detects a relatively high liquid temperature of the coolant immediately after flowing out of the cooling operation section 42, that is, the engine outlet liquid temperature T 2, and transmits the signal to the monitoring control section 7.

  In addition, a control valve 44 and a liquid heat exchanger 45 are provided in the return path 43 of the coolant circuit 4. The control valve 44 is a three-way valve that automatically controls the ratio of the flow divided to the buffer tank 3 and the bypass circuit 46 in accordance with the temperature of the coolant flowing through the inside. The inflow port 441 of the control valve 44 is in communication with the outlet of the cooling operation unit 42. The low temperature outflow port 442 of the control valve 44 communicates with the suction port 51 of the circulation pump 5 using the bypass circuit 46. The high temperature outflow port 443 of the control valve 44 communicates with the liquid inlet 32 of the buffer tank 3 via the primary side pipe 451 of the liquid heat exchanger 45.

  When the coolant flowing inside the control valve 44 is below a predetermined low temperature value, the low temperature outflow port 442 is opened and the high temperature outflow port 443 is closed. At this time, the coolant flows from the inflow port 441 to the low temperature outflow port 442. 60 degreeC can be illustrated as a predetermined | prescribed low temperature value, It is not limited to this. When the coolant is equal to or higher than a predetermined high temperature value, the low temperature outflow port 442 is closed and the high temperature outflow port 443 is opened. At this time, the coolant flows from the inflow port 441 to the high temperature outflow port 443.

  Further, when the coolant is between a predetermined low temperature value and a high temperature value, both the low temperature outflow port 442 and the high temperature outflow port 443 open at an opening degree depending on the liquid temperature, and the outflow diversion ratio is automatically set. Be controlled. That is, when the coolant is close to a predetermined low temperature value, the diversion ratio of the low temperature outflow port 442 is large and the diversion ratio of the high temperature outflow port 443 is small. As the coolant temperature increases from a predetermined low temperature value to a high temperature value, the diversion ratio of the low temperature outflow port 442 gradually decreases, and the diversion ratio of the high temperature outflow port 443 gradually increases.

  The liquid-liquid heat exchanger 45 is a part that makes the heat output of the gas engine generator 2 available outside as a co-generation system. The liquid-liquid heat exchanger 45 includes a primary side pipe 451 and a secondary side pipe 452, and heat is transferred from the coolant in the primary side pipe 451 to the heat transfer medium in the secondary side pipe 452. The secondary side heat transfer medium may be the same long life coolant as the primary side coolant or a different fluid. One end of the primary side pipe 451 communicates with the high temperature outflow port 443 of the control valve 44, and the other end communicates with the liquid inlet 32 of the buffer tank 3. The secondary side pipe 452 communicates with a heat load (not shown), and a peripheral circuit for using the heat output is formed.

  As shown in FIG. 1, the cooling device 1 for the power generation source according to the embodiment further includes a leakage prevention pan 8. The leakage prevention pan 8 is disposed below the buffer tank 3, the coolant circuit 4, and the circulation pump 5, and receives the coolant leaked from these 3, 4 and 5 to prevent leakage to the outside. To do. The allowable leakage amount of the coolant is determined based on the volume of the leakage prevention pan 8. That is, the allowable leakage amount of the coolant is determined by subtracting a certain margin from the volume of the leakage prevention pan 8.

  Here, FIG. 1 shows the liquid level position L1 of the coolant in the buffer tank 3 at the normal time when the coolant is not leaking. The buffer tank 3 has a liquid outlet 31 at the liquid surface position L2 when the coolant leaks to the limit of the allowable leakage amount. The liquid level position L2 is higher than the intermediate height in the buffer tank 3, and is set at a height position of about 70%. That is, the allowable leakage amount of the cooling liquid is determined so that the cooling liquid maintains a liquid surface position higher than the intermediate height in the buffer tank 3.

  On the other hand, the buffer tank 3 has a liquid inlet 32 at a position substantially lower than the liquid outlet 31 and close to the bottom. In general cooling devices, the liquid outlet is provided at the lower part of the buffer tank and the liquid inlet is often provided at the upper part of the buffer tank. In this embodiment, the vertical relationship between the liquid outlet 31 and the liquid inlet 32 is reversed. ing.

  The monitoring control unit 7 monitors the rotational speed N of the circulation pump 5, the engine inlet liquid temperature T1, and the engine engine outlet liquid temperature T2. As the monitoring control unit 7, for example, an electronic control device that incorporates a microcomputer and operates by software can be used. FIG. 2 is a flowchart illustrating the monitoring control flow of the monitoring control unit 7.

  When the gas engine generator 2 starts operation in step S1 of FIG. 2, the circulation pump 5 operates. In step S <b> 2, the monitoring controller 7 receives the signal of the engine inlet liquid temperature T <b> 1 from the engine inlet liquid temperature sensor 61 and the signal of the engine outlet liquid temperature T <b> 2 from the engine outlet liquid temperature sensor 62. Next, in step S3, it is determined whether or not a temperature abnormality of the coolant has occurred.

  More specifically, the engine inlet fluid temperature T1 is subtracted from the engine outlet fluid temperature T2 to obtain the vertical temperature difference ΔT (ΔT = T2−T1). When the vertical temperature difference ΔT is equal to or less than the allowable temperature difference, it is determined to be normal. When the vertical temperature difference ΔT exceeds the allowable temperature difference, it is determined that the temperature is abnormal. An example of the allowable temperature difference is 30 ° C., but is not limited thereto. The increase in the vertical temperature difference ΔT is caused by a decrease in the circulation amount of the coolant flowing through the cooling operation unit 42. Possible causes of such temperature abnormalities include air in the coolant, failure of the circulation pump 5, and constriction deformation of the coolant circuit 4.

  Further, the monitoring control unit 7 determines that the engine inlet liquid temperature T1 and the engine outlet liquid temperature T2 are equal to or lower than the allowable upper limit temperature, and at least one (usually the engine outlet liquid temperature T2) exceeds the allowable upper limit temperature. Sometimes it is determined that the heat storage limit is reached. 90 degreeC can be illustrated as an allowable upper limit temperature, It is not limited to this. The heat storage limit state occurs when the average liquid temperature of the cooling liquid gradually rises due to excess heat when the heat load is relatively small with respect to the electric load. Although the heat storage limit state is not an abnormal state, the operation of the gas engine generator 2 should not be continued.

  In step S3, when normal, the process proceeds to step S4, and when the temperature is abnormal and the heat storage limit state, the process proceeds to step S6. In step S <b> 4, the monitoring controller 7 receives a signal of the rotational speed N from the rotational speed sensor 55. Next, in step S5, it is determined whether an abnormality in the rotational speed of the circulation pump 5 has occurred. Specifically, when the rotational speed N is within a predetermined error range of the specified rotational speed, it is determined as normal and the process returns to step S2, and when the rotational speed N deviates from the predetermined error range, the rotational speed is abnormal. And the process proceeds to step S6.

  After returning to step S2, monitoring of the temperature abnormality of the coolant and the rotation speed abnormality of the circulation pump 5 is repeated. When the process proceeds to step S6 due to temperature abnormality, heat storage limit state, or rotation speed abnormality, the gas engine generator 2 is stopped as an abnormality measure. Moreover, when the gas engine generator 2 has a self-cooling power generation capacity, the electrical output may be lowered to a self-cooling power generation capacity or less as a measure for an abnormality. In addition, a general abnormality display or abnormality notification may be performed as a measure for an abnormality.

  Next, the operation and action of the cooling device 1 of the power generation source according to the embodiment configured as described above will be described. Drawing 3 is a figure showing the flow of the cooling fluid in cooling device 1 of the generating power source of an embodiment. In FIG. 3, a thick broken line loop indicates a flow when the coolant is below a predetermined low temperature value at the control valve 44, and a thick arrow indicates a flow when the coolant is above a predetermined high temperature value at the control valve 44. Show.

  When the gas engine generator 2 is operated and the circulation pump 5 is operating, the flow of the coolant is automatically controlled by the control valve 44. Immediately after the start of operation, etc., the coolant is below a predetermined low temperature value at the control valve 44, and the flow of the coolant is indicated by a thick dashed loop. That is, the cooling liquid discharged from the discharge port 52 of the circulation pump 5 passes through the engine inlet liquid temperature sensor 61 and enters the cooling operation unit 42 to cool the gas engine generator 2 and the liquid temperature rises. The coolant whose liquid temperature has risen exits the cooling action section 42 and passes through the engine outlet liquid temperature sensor 62, passes from the inflow port 441 of the control valve 44 through the low temperature outflow port 442, and then from the bypass circuit 46 to the circulation pump 5. Circulates to the suction port 51.

  Thus, when the coolant is at a low temperature, such as immediately after the start of operation, only a part of the coolant in the coolant circuit 4 is circulated, so that the coolant temperature rises quickly. When the coolant exceeds a predetermined low temperature value at the control valve 44, a part of the coolant flowing into the control valve 44 flows out from the high temperature outflow port 443. That is, the coolant is divided into the bypass circuit 46, the liquid heat exchanger 45 and the buffer tank 3. As a result, the liquid heat exchanger 45 can supply heat output to an external heat load.

  Further, when the coolant exceeds a predetermined high temperature value by the control valve 44, the low temperature outflow port 442 is completely closed, and the coolant flows as indicated by a thick arrow. That is, the coolant passes from the discharge port 52 of the circulation pump 5 through the engine inlet liquid temperature sensor 61, the cooling operation unit 42, and the engine outlet liquid temperature sensor 62 and reaches the inflow port 441 of the control valve 44. Further, the coolant flows out from the high temperature outflow port 443 of the control valve 44, passes through the primary side pipe 451 of the liquid heat exchanger 45, and flows into the buffer tank 3 from the liquid inlet 32.

  Here, the coolant that has flowed into a position near the bottom of the buffer tank 3 has a relatively high temperature and a low density as compared with the stored coolant, and is thus stored while rising in the buffer tank 3. Mix with the coolant. Thereby, the liquid temperature of the cooling liquid in the buffer tank 3 is made substantially uniform. On the other hand, the coolant flows out from the liquid outlet 31 of the buffer tank 3 and is circulated to the circulation pump 5 by the suction pressure of the suction port 51 of the circulation pump 5.

  The heat output can be used even when the gas engine generator 2 is stopped. In other words, even when the gas engine generator 2 is stopped, if the heat stored in the coolant in the buffer tank 3 has already been sufficiently stored and the liquid temperature exceeds the predetermined high temperature value of the control valve 44, the circulation is performed. The pump 5 can be operated. As a result, the coolant circulates as indicated by the thick arrows, and the heat output from the liquid heat exchanger 45 can be supplied to an external heat load.

  Next, the operation when the coolant leaks will be described. FIG. 4 is a diagram illustrating an operation when the coolant leaks to the limit of the allowable leakage amount in the cooling device 1 of the power generation source according to the embodiment. If the coolant leaks from the buffer tank 3, the coolant circuit 4, and the circulation pump 5 for some reason, the coolant is received by the leakage prevention pan 8 to prevent leakage to the outside. When the leakage amount reaches the limit of the allowable leakage amount, the liquid level position L2 of the cooling liquid in the buffer tank 3 exactly matches the liquid outlet 31 as shown in FIG.

  For this reason, air comes to be mixed into the coolant that flows out from the liquid outlet 31 and travels toward the circulation pump 5. Thereby, in the circulation pump 5, a load becomes light and the rotation speed N increases. Further, the actual circulation amount of the coolant flowing through the cooling operation unit 42 is decreased, and the vertical temperature difference ΔT is increased. Therefore, the monitoring controller 7 can detect a shortage of the coolant circulation amount.

  Further, when the leakage continues and the liquid level L3 of the coolant in the buffer tank 3 is slightly lower than the liquid outlet 31, only air circulates through the coolant circuit 4. Therefore, the abnormality in the rotational speed N of the circulation pump 5 and the abnormality in the upper and lower temperature difference ΔT become prominent, and the monitoring controller 7 can more reliably detect the insufficient circulation amount of the coolant.

  Next, the effect of the cooling device 1 of the power generation source of the embodiment will be described in comparison with the reference embodiment. FIG. 5 is an overall configuration diagram schematically illustrating a cooling device 9 for a power generation source according to a reference embodiment. Each part which comprises the cooling device 9 of a reference form substantially corresponds to embodiment, and the height position of liquid outlet 31A and liquid inlet 32A of buffer tank 3A differs. That is, the liquid outlet 31A is provided in the lower part of the buffer tank 3A, and the liquid inlet 32A is provided in the upper part of the buffer tank 3A.

  In the reference mode, when the monitoring controller 7A monitors the rotational speed N and the vertical temperature difference ΔT of the circulation pump 5, most of the cooling liquid in the buffer tank 3A leaks and the liquid surface position L4 enters the lower liquid outlet 31A. It is not possible to detect a shortage of circulation until it decreases. Therefore, in order to perform rapid abnormality detection, it is necessary to provide a liquid level sensor 33 of, for example, a light reflection detection method in the buffer tank 3A and transmit a signal of the liquid level position to the monitoring control unit 7A.

  On the other hand, in the embodiment, even if the liquid level sensor 33 is omitted and the cost is reduced, the liquid level position L2 higher than the intermediate height of the buffer tank 3 when the coolant leaks to the limit of the allowable leakage amount. An abnormality in the rotational speed N and an abnormality in the vertical temperature difference ΔT occur at (about 70% height position). Therefore, the monitoring control unit 7 can detect an insufficient circulation amount of the coolant without delay, and can quickly carry out an abnormality treatment.

  Furthermore, since the allowable leakage amount of the coolant is determined based on the volume of the leakage prevention pan 8, it is possible to reliably detect the insufficient circulation amount of the coolant before the leaked coolant begins to leak outside. Further, it is possible to reliably detect an insufficient circulation amount of the coolant at a slight stage of leakage where the coolant remains up to a height position of about 70% of the buffer tank 3.

  Furthermore, since the liquid inlet 32 is provided at a position lower than the liquid outlet 31 of the buffer tank 3, it becomes easy to make the cooling liquid inside the buffer tank 3 uniform and maintain an appropriate temperature, thereby eliminating the possibility that the cooling performance will deteriorate. it can. Moreover, since the bypass circuit 46 and the control valve 44 are provided, the warm-up operation at the start of the gas engine generator 2 can be made efficient.

  Further, since the gas engine generator 2 is used in a cogeneration system, a heat output can be obtained from the coolant circuit 4 using the liquid-liquid heat exchanger 45. In addition, it is easy to maintain the coolant at an appropriate temperature, and the heat output can be used efficiently.

  In addition, it is also possible to replace the gas engine generator 2 as a power generation source of the embodiment with a fuel cell. Further, the leakage prevention pan 8 is not necessary, and the control valve 44 and the bypass circuit 46 in the coolant circuit 4 may be omitted. Further, the liquid surface position L2 of the buffer tank 3 when the coolant leaks to the limit of the allowable leakage amount is an example of a height position of about 70%, and can be changed as appropriate. Various other applications and modifications are possible for the present invention.

1: Cooling device for power generation 2: Gas engine generator (power generation)
3, 3A: Buffer tank 31, 31A: Liquid outlet 32, 32A: Liquid inlet 33: Liquid level sensor 4: Cooling liquid circuit 41: Outward path part 42: Cooling action part 43: Return path part 44: Control valve 45: Liquid heat Exchanger 46: Bypass circuit 5: Circulation pump 55: Speed sensor 61: Engine inlet liquid temperature sensor 62: Engine outlet liquid temperature sensor 7: Monitoring control unit 8: Leakage prevention pan T1: Engine inlet liquid temperature T2: Engine outlet liquid Temperature N: Number of rotations of circulation pump

Claims (6)

A buffer tank for storing a coolant for cooling a power generation source composed of a gas engine generator or a fuel cell, and a cooling fluid which is disposed in contact with the power generation source and includes the buffer tank and through which the coolant flows. A liquid circuit, a circulation pump for circulating the cooling liquid in the cooling liquid circuit, a rotation speed sensor for detecting the rotation speed of the circulation pump, and a temperature of the cooling liquid provided in the middle of the cooling liquid circuit A liquid temperature sensor to detect, and a monitoring control unit for monitoring the number of rotations of the circulation pump and the temperature of the cooling liquid,
The buffer tank has a liquid outlet through which the cooling liquid flows into the cooling liquid circuit at a liquid surface position when the cooling liquid leaks to a limit of an allowable leakage amount,
The monitoring control unit is a cooling device for a power generation source that detects an insufficient circulation amount of the coolant based on an abnormality in at least one of the number of rotations of the circulation pump and the temperature of the coolant. A leak prevention pan that receives the coolant leaked from the buffer tank, the coolant circuit, and the circulation pump to prevent leakage to the outside;
The cooling device for a power generation source according to claim 1, wherein an allowable leakage amount of the coolant is determined based on a volume of the leakage prevention pan.   3. The cooling device for a power generation source according to claim 1, wherein the allowable leakage amount of the cooling liquid is determined so that the cooling liquid maintains a liquid surface position higher than an intermediate height in the buffer tank.   The said buffer tank is a cooling device of the power generation source as described in any one of Claims 1-3 which has the liquid inlet in which the said coolant flows in from the said coolant circuit in the position lower than the said liquid outlet.   2. The coolant circuit includes a bypass circuit that circulates the coolant without passing through the buffer tank, and a control valve that controls a ratio at which the coolant is divided into the buffer tank and the bypass circuit. The cooling device of the power generation source as described in any one of -4.   The cooling of the power generation source according to any one of claims 1 to 5, wherein the power generation source is used in a cogeneration system for obtaining an electrical output and a heat output, and the coolant circuit is a circuit for obtaining the heat output. apparatus.

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