JPWO2010013316A1 - Hybrid power generation system and operation method thereof - Google Patents

Abstract

The compressor 1 that compresses the intake air 30, the regenerative heat exchanger 4 that heats the compressed air 31 from the compressor, and the compressed air from the regenerative heat exchanger is heated by the reaction heat of the cell fuel 60, and the reaction of the cell fuel From the fuel cell 10 that generates a high-temperature gas 33 containing water as a product, the turbine 2 that is driven by the high-temperature gas from the fuel cell, and discharges the exhaust gas 35 that serves as a heat source to the regenerative heat exchanger, and the regenerative heat exchanger The heat exchanger 14 for condensing and recovering water in the exhaust gas of the exhaust gas, the water supply tank 20 for storing the water recovered by the heat exchanger, and the water in the water supply tank 20 for the intake air 30 and the compressed air 31 And a feed water pump 50 to be supplied. As a result, water generated in the fuel cell 10 can be used to spray water on the intake air of the gas turbine and the like, so that output can be improved and efficiency can be increased while suppressing costs.

Description

  The present invention relates to a hybrid power generation system that generates power using a gas turbine and a fuel cell, and an operation method thereof.

  Micro gas turbines and fuel cells have been developed as distributed power sources with good overall efficiency. A fuel cell is basically a system that generates electricity by a reaction between hydrogen and oxygen, and generates water as a reaction product. Unlike a gas turbine or a reciprocating engine that generates power using a thermal cycle, a fuel cell is a system that directly generates power using a chemical reaction, and thus has a significantly higher power generation efficiency than a gas turbine.

  In recent years, in order to further improve the power generation efficiency, a hybrid power generation system combining a fuel cell and a gas turbine has been developed. In a normal gas turbine, the working medium is heated by a combustor. In this hybrid power generation system, a fuel cell performs part or all of the temperature rise of the working medium instead of the combustor. Can be improved.

By the way, as a technique for improving the output and improving the efficiency of a gas turbine alone, a technique equipped with a humidifying facility for spraying water obtained from the outside to the intake air or compressed air of the gas turbine has been proposed (for example, JP 2002-124605 A). No. 138852).
JP 2002-138852 A

  However, the above-mentioned document describing this technology does not disclose any method for applying the humidification facility to the hybrid power generation system.

  In addition, as one of the specific problems that can be an obstacle to the introduction of humidification equipment into a hybrid power generation system, there is a problem of costs associated with the introduction and maintenance of the humidification equipment. First, when water is sprayed constantly on the intake air or the like with a humidifying facility, the running cost for securing the water for the water supply becomes a problem. In the above technique, in order to reduce the running cost, a water recovery device for recovering and reusing water from the exhaust of the gas turbine is provided. The accompanying initial cost is the next problem.

  For this reason, when trying to introduce humidification equipment into a hybrid power generation system, it is expected that the introduction of humidification equipment will be postponed when the degree of improvement in power generation efficiency by water spraying is low compared to the associated costs. The This problem becomes even more pronounced in places and situations where water cannot be introduced from the outside.

  The objective of this invention is providing the hybrid electric power generation system which can aim at the output improvement and high efficiency, suppressing the cost, and its operating method.

  In order to achieve the above object, the present invention provides a compressor that compresses intake air, a regenerative heat exchanger that heats compressed air from the compressor, and a reaction of battery fuel with compressed air from the regenerative heat exchanger. A fuel cell that is heated by heat and generates a high-temperature gas containing water, which is a reaction product of battery fuel, and a turbine that is driven by the high-temperature gas from the fuel cell and discharges exhaust gas that serves as a heat source to the regenerative heat exchanger A heat exchanger that condenses and recovers water in the exhaust gas from the regenerative heat exchanger, a water supply tank that stores water recovered by the heat exchanger, intake air of the compressor, and the compression And a water supply pump for supplying water from the water supply tank to the compressed air supplied from the machine to the fuel cell.

  According to the present invention, water generated in the fuel cell can be used to spray water on the intake of a gas turbine and the like, so that it is possible to improve output and increase efficiency while suppressing costs.

The system block diagram of the hybrid electric power generation system which is the 1st Embodiment of this invention. 1 is a configuration diagram of a fuel cell 10 according to a first embodiment of the present invention. The system block diagram of the hybrid electric power generation system which is a comparative example regarding the 1st Embodiment of this invention. 1 is a system configuration diagram of a regeneration cycle gas turbine using high humidity air that is a comparative example related to the first embodiment of the present invention. FIG. Explanatory drawing of the system starting schedule which concerns on the hybrid electric power generation system which is the 1st Embodiment of this invention. The system block diagram of the hybrid electric power generation system which is the 2nd Embodiment of this invention. The system block diagram of the hybrid electric power generation system which is the 3rd Embodiment of this invention. Explanatory drawing of the system starting schedule which concerns on the hybrid electric power generation system which is the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Turbine 3 Combustor 4 Regenerative heat exchanger 7 Water lubrication bearing 10 Fuel cell 14 Heat exchanger 15 Electric power 20 Water supply tank 21 Circulating water tank 30 Intake 31 Compressed air 32 Compressed air 33 Hot gas 34 Combustion gas 35 Exhaust gas 37 Refrigerant 41 Water supply line 42 Water supply line 43 Water supply line 50 Water supply pump 55 Spraying device 56 Humidifier 60 Battery fuel 61 Combustion fuel 70 Water supply tank water amount set value 71 Water supply pump start time 72 Circulating water tank water amount set value 73 Gas turbine start time 80 On-off valve

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a system configuration diagram of a hybrid power generation system according to a first embodiment of the present invention.

  The hybrid power generation system shown in this figure includes a compressor 1 that compresses and discharges intake air 30 that has passed through a spray device 55, a regenerative heat exchanger 4 that heats compressed air 31 from the compressor 1, and a regenerative heat exchanger. The fuel cell 10 that heats the compressed air 32 from the fuel 4 with the reaction heat of the fuel (cell fuel) 60 to generate the hot gas 33 containing water, which is the reaction product of the cell fuel, and the hot gas 33 from the fuel cell 10 From the turbine 2 that discharges the exhaust gas 35 as a heat source to the regenerative heat exchanger 4, the water supply tank 20 that stores the water generated by the fuel cell 10, the intake air 30 of the compressor 1, and the compressor 1. A water supply pump 50 that supplies water from the water supply tank 20 to the compressed air 31 supplied to the regenerative heat exchanger 4 is provided.

  The turbine 2 rotates the compressor 1 and the generator 5 connected to the turbine 2 by the driving force given by the hot gas 33. The regenerative heat exchanger 4 exchanges heat between the exhaust gas 35 from the turbine 2 and the compressed air 31 to heat the compressed air 31 and cool the exhaust gas 35. The cycle provided with the regenerative heat exchanger 4 is referred to as a regeneration cycle, and the power generation efficiency is higher than the cycle not provided with the regenerative heat exchanger 4. The exhaust gas 36 cooled by the regenerative heat exchanger 4 is supplied to the fuel cell 10. Next, the fuel cell 10 will be described in detail.

  FIG. 2 is a configuration diagram of the fuel cell 10 according to the present embodiment. In addition, the same code | symbol is attached | subjected to the same part as the previous figure, and description is abbreviate | omitted (a later figure is handled similarly).

  In the present embodiment, a case where a solid oxide fuel cell (SOFC) is used as the fuel cell 10 will be described. In this type of fuel cell, hydrogen may not be directly used as the fuel (cell fuel) 60 but may be used as the fuel 60 by reforming a hydrocarbon-based fuel such as natural gas to produce hydrogen.

  The fuel cell 10 shown in this figure includes an evaporator 13, a reformer 12, a battery unit 11, and a heat exchanger 14. In this figure, the components such as the preheater are omitted for simplification.

  The evaporator 13 evaporates the water from the water supply tank 20 with the high temperature gas 33, and is connected to the water supply tank 20 via a pump 52. A high temperature gas 33 generated in the battery unit 11 is introduced into the evaporator 13 of the present embodiment, and the high temperature gas 33 is used as a heat source for heating water from the water supply tank 20. The steam generated in the evaporator 13 is supplied to the reformer 12.

  The reformer 12 reforms the fuel (for example, natural gas) 60 with the steam from the evaporator 13, and is connected to the evaporator 13. Like the evaporator 13, the reformer 12 of the present embodiment is introduced with a high-temperature gas 33 generated in the battery unit 11, and the high-temperature gas 33 is used as a heat source when reforming the fuel 60. ing. The fuel 60 reformed by the reformer 12 is supplied to the battery unit 11.

  The battery unit 11 generates electric power 15 by a chemical reaction of the fuel 60 from the reformer 12, and is connected to the reformer 12 and the regenerative heat exchanger 4. Fuel 60 is supplied from the reformer 12 to the anode (not shown) of the battery unit 11, and oxygen-containing air (fuel cell intake air) from the regenerative heat exchanger 4 is supplied to the cathode (not shown) of the battery unit 11. ) 32 is supplied, and electric power 15 is generated by a chemical reaction caused by these. During this chemical reaction, water (fuel cell wastewater) is generated as a reaction product at the anode, and is contained as water vapor in the exhaust gas generated by the chemical reaction. The exhaust gas generated at the anode and the cathode is heated by the reaction heat generated by the chemical reaction and becomes a high-temperature gas (fuel cell exhaust (for example, about 600 to 1000 degrees)) 33 and is discharged from the battery unit 11. The hot gas 33 is supplied to the turbine 2 after being used as a heat source for the evaporator 13, the reformer 12, and the like.

  The heat exchanger (exhaust heat recovery heat exchanger) 14 condenses and recovers moisture (fuel cell waste water) in the exhaust gas 36 by exchanging heat between the exhaust gas 36 from the regeneration heat exchanger 4 and the refrigerant 37. A heat exchanger 4 is connected. The water recovered by the heat exchanger 14 is stored in the water supply tank 20 via the water supply line 40. On the other hand, the exhaust gas 39 cooled by the heat exchanger 14 is discharged to the outside. As a specific example of the refrigerant 37 for cooling the exhaust gas 36, there is air, but a part of the water stored in the water supply tank 20 may be used. In this case, it is preferable to separately configure a circulation system that circulates and supplies part of the water in the water supply tank 20 to the heat exchanger 14. In addition, if a radiator is installed in the circulation system, the refrigerant temperature of the heat exchanger 14 can be lowered, so that water can be efficiently condensed and recovered from the exhaust gas 36.

  Moreover, it is preferable to provide a dewatering device (not shown) such as a reverse osmosis membrane between the heat exchanger 14 and the water supply tank 20 or between the water supply tank 20 and the water supply pump 50. By providing a dewatering device in this way, impurities contained in the recovered water can be removed, so that components such as the compressor 1 may be damaged even if the water is supplied to various places in the system. Can be prevented.

  Here, the case where SOFC is used as the fuel cell 10 has been described. However, a molten carbonate fuel cell (MCFC) may be used.

  Returning now to FIG. The power generation system shown in FIG. 1 includes a water supply line 41, a water supply line 42, a spray device 55, and a humidifier 56.

  The water supply line 41 supplies water to the spray device 55, and is connected to the water supply tank 20 via the water supply pump 50. The water supply line 42 supplies water to the humidifier 56 and is connected to the water supply tank 20 via the water supply pump 50. The water in the water supply tank 20 is pressurized by the water supply pump 50 and supplied to the spray device 55 and the humidifier 56.

  The spray device 55 performs water spraying inlet air cooling (WAC), and is installed on the upstream side of the compressor 1. When water is sprayed on the intake air 30 in this way, effects such as lowering the temperature of the intake air 30 to increase the suction flow rate of the compressor 1 and lowering the driving power of the compressor 1 can be obtained.

  The humidifier 56 constitutes a humidified turbine (Humid Air Turbine (HAT)) by spraying water on the compressed air 31 to form the humidified air, and between the compressor 1 and the regenerative heat exchanger 4. is set up. When the compressed air 31 is humidified in this way, the temperature of the compressed air 31 decreases, so the temperature of the exhaust 36 decreases, and the heat recovery of the turbine exhaust gas 35 by the regenerative heat exchanger 4 increases, so that the thermal efficiency improves. An effect can be obtained. A specific example of the humidifier 56 is a humidifier tower. This humidifying tower sprinkles water from above with respect to the air passing through the inside of the tower from below to increase the moisture content of the air.

  Next, the operation and effect of the present embodiment will be described with reference to a comparative example.

  FIG. 3 is a system configuration diagram of a hybrid power generation system that is a comparative example of the present embodiment, and FIG. 4 is a system configuration diagram of a high-humidity air utilization regeneration cycle gas turbine that is a comparative example of the present embodiment.

  The hybrid power generation system shown in FIG. 3 is a combination of a gas turbine and a fuel cell. A hot gas 33 generated in the fuel cell 10 is supplied to the turbine 2 without spraying water on the intake air 30 or increasing the humidity of the compressed air 31. Supply. That is, the system of FIG. 3 corresponds to a hybrid power generation system according to the present embodiment in which the water supply tank 20, the water supply pump 50, the water supply line 41, the spray device 55, the water supply line 42, and the humidifier 56 are omitted. The difference from the present embodiment is that water 49 obtained as a reaction product in the fuel cell 10 is drained to the outside. In such a hybrid power generation system, the heat obtained by the chemical reaction in the fuel cell 10 is recovered to a temperature that cannot be used for power generation while being discharged outside as exhaust gas. For this reason, it has been difficult to further improve the power output and efficiency of the hybrid power generation system from the viewpoint of heat recovery.

  Although not a technology related to the hybrid power generation system, as a technology for improving the output and improving the efficiency of the gas turbine alone that burns the fuel 61 in the combustor 3, water 46 obtained from the outside is used as in the system shown in FIG. Is provided with a spraying device 55 and a humidifier 56 (hereinafter referred to as “humidifying equipment” as appropriate).

  As one of the specific problems that may become an obstacle when introducing such humidifying facilities 55 and 56 into a hybrid power generation system, there is a cost problem associated with the introduction and maintenance of the humidifying facilities 55 and 56. First, when water is constantly sprayed to the intake air or the like with the humidifying equipment 55, 56, the running cost for securing water for supplying water becomes a problem. For example, the system described in Japanese Patent Laid-Open No. 2002-138852 is provided with a water recovery device for recovering and reusing water from the exhaust of the gas turbine in order to reduce the running cost. In some cases, the initial cost associated with the installation of the water recovery device becomes the next problem. Therefore, when the humidifiers 55 and 56 are to be introduced into the hybrid power generation system, when the degree of improvement in power generation efficiency by water spray is low compared to the costs associated with the humidifiers 55 and 56, the introduction of the humidifiers 55 and 56 is seen. It is expected to be combined. This problem becomes even more pronounced in places and situations where water cannot be introduced from outside.

  On the other hand, the hybrid power generation system of the present embodiment is configured to supply water in the water tank 20 that stores the water generated by the fuel cell 10 and the water in the water tank 20 to the intake air 30 and the compressed air 31. A pump 50 is provided. Accordingly, the water, which is a reaction product of the fuel cell 10, is recovered by the heat exchanger 14 without being discarded as wastewater and used as spray water or the like in the gas turbine, so that not only heat but also water can be used in a hybrid manner. Has been realized. In a certain system example, the amount of water used as reforming steam in the reformer 12 is about two-thirds of the water condensed and recovered by the heat exchanger 14, and the remaining one-third of the amount of water. The inventors have obtained the knowledge that the supply to the spraying device 55 and the humidifying device 56 can be covered within this range.

  When water generated in the fuel cell 10 is used in this way, it is not necessary to separately provide a water recovery device for recovering moisture from the exhaust gas 36, as well as reducing running costs for securing water for supplying water. The initial cost of the water recovery device and the equipment associated therewith can also be reduced. Therefore, according to the present embodiment, it is possible to achieve a remarkable effect that the output can be improved and the efficiency can be improved while reducing the initial cost in addition to the running cost of the system. In particular, the present embodiment has an advantage that the system can be easily operated even in a place / situation where water cannot be introduced from the outside because water can be generated if the fuel 60 of the fuel cell 10 can be secured. Next, a method for starting the system of the present embodiment in a place / situation where water cannot be introduced from the outside will be specifically described.

  FIG. 5 is an explanatory diagram of a system startup schedule according to the hybrid power generation system of the present embodiment.

  In this figure, the vertical axis represents the amount of water and the electrical output, and the horizontal axis represents the elapsed time since the system was started. The set value 70 on the vertical axis is a minimum required value as the amount of water in the water supply tank 20 in order to supply water to the intake air 30 and the compressed air 31 via the spray device 55 and the humidifier 56. As a means for measuring the amount of water in the water supply tank 20, for example, there is a level gauge. Here, if the amount of water in the water supply tank 20 is maintained at the set value 70 or more, the output and efficiency of the hybrid power generation system according to the present embodiment can be improved. A time 71 on the horizontal axis indicates a time when the water supply pump 50 is activated.

  In a place / situation where water cannot be introduced from the outside, the inside of the water supply tank 20 is initially empty (or less than the set value 70), and the spray device 55 and the humidifier 56 cannot spray water. Therefore, as shown in this figure, first, without supplying water to the water supply line 41 and the water supply line 42 (that is, without starting the water supply pump 50), the gas turbine (the compressor 1, the regenerative heat exchanger 4, the turbine) 2) and the fuel cell 10 is started. When the fuel cell 10 is started, water generated inside the fuel cell 10 accumulates in the water supply tank 20, and the amount of water increases with time. Thereafter, after the amount of water in the water supply tank 20 reaches the set value 70, the water supply pump 50 is activated to start water spraying (time 71). After this time 71, water spray can be performed by the spray device 55 and the humidifier 56, so that the electrical output of the system can be improved as shown in FIG.

  If the system is started in this manner, the hybrid power generation system according to the present embodiment can be operated even in an area with little water by using the water generated in the fuel cell 10. That is, after the time 71 when the feed water pump 50 is activated, the output and efficiency improvement effects by the spray device 55 and the humidifier 56 can be exhibited.

  It should be noted that a control device that senses the amount of water in the water supply tank 20 and transmits an activation signal to the water supply pump 50 when the amount of water reaches the set value 70 may be provided to automatically control the activation of the water supply pump 50.

  In the above description, the case where water is supplied to the spray device 55 and the humidifier 56 at the same time has been described. However, the set value of the water supply tank 20 for starting water supply to the spray device 55 and the water supply to the humidifier 56 are started. The set value of the water supply tank 20 may be set individually, and a time difference may be provided in the time when water supply is started to the spray device 55 and the humidifier 56. In this case, the water supply line 41 and the water supply line 42 need to be configured to supply water individually. As a specific example of the configuration, water supply means such as a water supply pump is provided in both the water supply lines 41 and 42. Alternatively, there is a type in which a water supply pump is attached to one of the water supply lines 41 and 42 and a valve is attached to the other.

  Further, when the system is provided with a circulation system that circulates and supplies the water in the water supply tank 20 as the refrigerant 37 of the heat exchanger 14, air is used as the refrigerant 37 from the time the system is started until the amount of water for the refrigerant 37 is accumulated. Use it.

Next, a second embodiment of the present invention will be described.
FIG. 6 is a system configuration diagram of a hybrid power generation system according to the second embodiment of the present invention.

  The hybrid power generation system shown in this figure is different from that of the first embodiment in that a combustor 3 is provided between the fuel cell 10 and the turbine 2. The combustor 3 adds a fuel (combustion fuel) 61 to the high-temperature gas 33 from the fuel cell 10 and burns it, thereby generating a combustion gas 34 to be supplied to the turbine 2.

  When the combustor 3 is provided on the downstream side of the fuel cell 10 as described above, the temperature of the high temperature gas 33 can be increased by a combustion reaction, so that the combustion gas 34 having a desired temperature is obtained by adjusting the amount of the fuel 61 or the like. be able to. Further, when the combustor 3 is provided, even when unreacted fuel (cell fuel) 60 remains in the high-temperature gas 33, these can be burned, so that the usage rate of the fuel 60 can be improved. it can. In general, the higher the temperature of the combustion gas 34, the higher the output and efficiency of the gas turbine. However, the level of the combustion gas 34 depends on the design of the gas turbine and the total system design of the hybrid power generation system. .

Next, a third embodiment of the present invention will be described.
FIG. 7 is a system configuration diagram of a hybrid power generation system according to the third embodiment of the present invention.

  The hybrid power generation system shown in this figure mainly includes a water-lubricated bearing 7 that supports the shaft of the turbine 2, a circulating water tank 21 that stores water supplied from the water supply tank 20, and water in the circulating water tank 21. Is different from that of the first embodiment in that a circulation pump 51 is provided for circulating and supplying water to the water-lubricated bearing 7. The system shown in this figure is provided with the combustor 3. However, when the temperature of the inlet of the turbine 2 is sufficient as the temperature of the hot gas 33 from the fuel cell 10, the system of the first embodiment is used. Similarly, the combustor 3 may be omitted.

  Water-lubricated bearings 7 are installed at both ends of the generator rotor 6. A water supply line 44 is connected to the water lubrication bearing 7, and water in the circulating water tank 21 is circulated and supplied by a circulation pump 51. The water supplied to the water-lubricated bearing 7 via the water supply line 44 is then drained via the drainage line 45 and returns to the circulating water tank 21. When a relatively small size (for example, several hundreds kW) and a turbine that rotates at high speed are used in the hybrid power generation system, if the water-lubricated bearing 7 is used as a bearing, the bearing loss is reduced as compared with the case where lubricating oil is used. And high efficiency can be achieved. If the water-lubricated bearing 7 is used, a so-called oil-free system that does not use any oil can be constructed. As a result, the hybrid power generation system can be constructed even in an environment where oil cannot be used (for example, a food factory), so that the environmental characteristics of the system are improved.

  The circulating water tank 21 is connected to the water supply tank 20 via a water supply line 43. Lubricating water circulated and supplied to the water-lubricated bearing 7 evaporates during the circulation or leaks, and therefore gradually decreases. The water supply line 43 is for compensating for the decrease in the lubricating water. The water supply line 43 is provided with an on-off valve 80.

  The on-off valve 80 is opened so that the amount of water in the circulating water tank 21 is maintained at or above the minimum required value (set value 72 in FIG. 8) as the amount of water for using the water lubricated bearing 7. When the on-off valve 80 is opened, the water in the water supply tank 21 is supplied to the circulating water tank 21 via the water supply line 43. In this case, depending on the height relationship between the water supply tank 20 and the circulating water tank 21, water may naturally flow from the water tank 20 to the circulating water tank 21 due to its own weight. In this case, when the lubricating water decreases, the water can be replenished simply by opening the on-off valve 80. On the other hand, when water does not flow naturally into the circulating water tank 21 due to its own weight, it is necessary to install a water supply pump in the water supply line 43 and operate the pump as necessary.

  According to the embodiment configured as described above, even if the lubricating water is reduced by continuous use of the water-lubricated bearing 7, the water in the water supply tank 20 (generated by the fuel cell 10 is generated through the water supply line 43. Water). Thereby, an oil-free system can be constructed without separately preparing water for replenishing circulating water. This is a particularly advantageous merit in places and situations where water cannot be introduced from the outside. Moreover, since the consumption of the water produced | generated by the fuel cell 10 can be increased compared with said each embodiment, the hybrid system which the utilization factor of water improved further can be constructed | assembled. Next, a method for starting the system of the present embodiment in a place / situation where water cannot be introduced from the outside will be specifically described.

  FIG. 8 is an explanatory diagram of a system startup schedule according to the hybrid power generation system of the present embodiment.

  The vertical axis of this figure shows the amount of water in the circulating water tank 21 and the operating state of the gas turbine and the fuel cell 10, and the horizontal axis shows the elapsed time since the system startup. The set value 72 on the vertical axis is a minimum required value as the amount of water in the circulating water tank 21 for using the water-lubricated bearing 7. As a means for measuring the amount of water in the circulating water tank 21, for example, there is a level gauge. A time 73 on the horizontal axis indicates a time when the gas turbine is started.

  In a place / situation where water cannot be introduced from the outside, the circulating water tank 21 is initially empty (or less than the set value 72), the water lubricated bearing 7 cannot be used, and the gas turbine cannot be started. Therefore, as shown in this figure, first, only the fuel cell 10 is started while the gas turbine is stopped. When the fuel cell 10 is started, the water generated in the fuel cell 10 is accumulated in the water supply tank, and the water is supplied to the circulating water tank 21 through the water supply line 43. When the amount of water in the circulating water tank 21 increases and reaches the set value 70, the circulating pump 51 is started thereafter to operate the water lubrication system, and the gas turbine is started (time 73). If the system is started in this way, the oil-free hybrid power generation system according to the present embodiment can be operated even in an area where there is little water by using the water generated in the fuel cell 10. Environmental characteristics are further improved.

  At this time, if the fuel cell provided in the system is of a type that does not require fuel reforming, it is not necessary to use water for reforming steam during operation of the fuel cell. Therefore, since all the water in the water supply tank 20 can be supplied to the circulating water tank 21, a gas turbine can be started earlier than the case of the fuel cell 10 demonstrated above.

  In addition, when the gas turbine is started (time 73), the amount of water required to be supplied to the spray device 55 and the humidifier 56 is not in the water supply tank 20, which has been described with reference to FIG. As in the example, water spraying may be started after the necessary amount of water has accumulated. Furthermore, as described in relation to FIG. 5, a control device is provided that senses the amount of water in the circulating water tank 21 and transmits a start signal to the gas turbine when the amount of water reaches the set value 72, thereby starting the gas turbine. Needless to say, automatic control may be performed.

Claims (11)

A compressor that compresses the intake air;
A regenerative heat exchanger for heating the compressed air from the compressor;
A fuel cell that heats the compressed air from the regenerative heat exchanger with the reaction heat of the cell fuel, and generates a high-temperature gas containing water that is a reaction product of the cell fuel;
A turbine driven by high-temperature gas from the fuel cell and exhausting exhaust gas as a heat source to the regenerative heat exchanger;
A heat exchanger for condensing and recovering water in the exhaust gas from the regenerative heat exchanger;
A water supply tank for storing the water recovered by the heat exchanger;
A hybrid power generation system comprising: a water supply pump that supplies water from the water supply tank to intake air of the compressor and compressed air supplied from the compressor to the fuel cell. The hybrid power generation system according to claim 1,
Start the fuel cell,
The hybrid power generation characterized in that after the amount of water in the water supply tank reaches a minimum required value as the amount of water to be supplied to the intake air of the compressor, water is sprayed on the intake air using the water supply pump. system. The hybrid power generation system according to claim 1,
Start the fuel cell,
After the amount of water in the water supply tank reaches the minimum required value as the amount of water to be supplied to the compressed air supplied from the compressor to the regenerative heat exchanger, the compressed air is used by using the water supply pump. A hybrid power generation system characterized by spraying water on the surface. The hybrid power generation system according to claim 1,
Start the fuel cell,
After the amount of water in the water supply tank reaches the minimum required value as the amount of water to be supplied to the intake air of the compressor and the compressed air supplied from the compressor to the regenerative heat exchanger, the water supply pump A hybrid power generation system using water to spray the intake air and the compressed air. The hybrid power generation system according to claim 1,
A water-lubricated bearing that supports the turbine shaft;
A circulating water tank in which water supplied from the water supply tank is stored;
The hybrid power generation system further comprising: a circulation pump that circulates and supplies the water in the circulation water tank to the water-lubricated bearing. The hybrid power generation system according to claim 5, wherein
The water in the water tank is supplied to the circulating water tank so that the amount of water in the circulating water tank is maintained at a value more than a minimum required as the amount of water for using the water lubricated bearing. Hybrid power generation system. The hybrid power generation system according to claim 5, wherein
Start the fuel cell,
The gas turbine having the compressor, the regenerative heat exchanger, and the turbine is started after the amount of water in the circulating water tank reaches a minimum required value as the amount of water for using the water-lubricated bearing. A hybrid power generation system characterized by that. The hybrid power generation system according to claim 7, wherein
After starting the gas turbine, the amount of water in the water supply tank is the minimum required as the amount of water to be supplied to the intake air of the compressor and the compressed air supplied from the compressor to the regenerative heat exchanger The hybrid power generation system is characterized by starting the water supply pump after reaching a certain value. The hybrid power generation system according to claim 1,
A hybrid power generation system further comprising a combustor that adds combustion fuel to the high-temperature gas from the fuel cell and burns the fuel cell to generate combustion gas for supply to the turbine. A compressor that compresses the intake air;
A regenerative heat exchanger for heating the compressed air from the compressor;
A fuel cell that heats the compressed air from the regenerative heat exchanger with the reaction heat of the cell fuel, and generates a high-temperature gas containing water that is a reaction product of the cell fuel;
A turbine driven by high-temperature gas from the fuel cell and exhausting exhaust gas as a heat source to the regenerative heat exchanger;
A heat exchanger for condensing and recovering water in the exhaust gas from the regenerative heat exchanger;
A method for operating a hybrid power generation system comprising a water supply tank in which water collected by the heat exchanger is stored,
Start the fuel cell,
After the amount of water in the water supply tank reaches the minimum required value as the amount of water to be supplied to the intake air of the compressor and the compressed air supplied from the compressor to the regeneration heat exchanger, the water supply tank The method for operating a hybrid power generation system is characterized in that water is supplied to the intake air and the compressed air. A compressor that compresses the intake air;
A regenerative heat exchanger for heating the compressed air from the compressor;
A fuel cell that heats the compressed air from the regenerative heat exchanger with the reaction heat of the cell fuel, and generates a high-temperature gas containing water that is a reaction product of the cell fuel;
A turbine driven by high-temperature gas from the fuel cell and exhausting exhaust gas as a heat source to the regenerative heat exchanger;
A heat exchanger for condensing and recovering water in the exhaust gas from the regenerative heat exchanger;
A water supply tank for storing the water recovered by the heat exchanger;
A water supply pump for supplying water in the water supply tank to the intake air of the compressor and the compressed air supplied from the compressor to the fuel cell;
A water-lubricated bearing that supports the turbine shaft;
A circulating water tank in which water supplied from the water supply tank is stored;
An operation method of a hybrid power generation system comprising a circulation pump for supplying water in the circulation water tank to the water lubricated bearing,
Start the fuel cell,
The gas turbine having the compressor, the regenerative heat exchanger, and the turbine is started after the amount of water in the circulating water tank reaches a minimum required value as the amount of water for using the water-lubricated bearing. An operation method of a hybrid power generation system characterized by the above.

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