JPS62119873A - Waste heat recovering device for combined power generation plant - Google Patents

Abstract

PURPOSE:To enhance the overall thermal efficiency of a combined power plant, by recovering the waste heat of a fuel cell power generation plant into the boiler feed water system of a thermal power generation plant. CONSTITUTION:The waste heat from the waste heat generation part of a fuel cell power plant is introduced through a feed water heating steam control valve 41 into the boiler feed water system of a thermal power generation plant, into which boiler feed water is introduced through a boiler feed water flow rate control valve 53, so that the boiler feed water is heated. After that, the waste heat from the fuel cell power generation plant is recovered back into the system of the fuel cell power generation plant from a drain tank 45 through a drain tank water level control valve 50. As a result, the thermal efficiency of the fuel cell plant is greatly enhanced and the fuel consumption rate of the thermal power generation plant is much reduced so that the overall thermal efficiency of a combined power plant is heightened.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a combined power generation plant consisting of a fuel cell power generation plant and a thermal power plant 11i, f. The present invention relates to an exhaust heat recovery device for a combined power generation plant that can improve overall thermal efficiency by recovering heat to the system.

[Technical background of the invention and its problems]

Conventionally, fuel ponds have been known as devices that directly convert energy contained in fuel into electrical energy. This fuel cell usually has a pair of electrodes, a fuel electrode and an oxidizer electrode, sandwiching an electrolyte layer, and a fuel such as hydrogen is brought into contact with the back of the fuel electrode, and an oxidizer such as air is placed in contact with the back of the oxidizer electrode. The electrical energy is extracted from between the pair of electrodes using the electrochemical reaction that occurs, and the electrical energy generated in the fuel cell is converted into electric power commensurate with the load command value using a power conversion device. Electrical energy can be extracted with high conversion efficiency as long as the above-mentioned fuel and oxidizer are supplied.

FIG. 3 is a block diagram showing an example of the configuration of a fuel cell power generation plant using this type of fuel cell. In the figure, 1 is a fuel processing device for reforming natural gas whose main component is, for example, methane gas into a gas mainly composed of hydrogen [H2], and 2 is an air processing device as an oxidizer processing device that obtains oxygen (02) from the air. It is. Reference numeral 3 designates a fuel cell comprising a pair of electrodes, a fuel electrode and an oxidizer electrode, with an electrolyte layer sandwiched between them. Oxygen from the air treatment device 2 is introduced as an oxidizing agent, and the oxygen is electrochemically reacted under high pressure using platinum or the like as a catalyst, and DC power, which is electrical energy, is extracted from between each electrode.

Reference numeral 4 denotes an orthogonal converter as a power converter that converts the DC power generated by the fuel cell 3 into AC power commensurate with the load command value, and this AC power is boosted by a converter transformer 5 as necessary. , and is supplied to the power system 7 via the interrupter 6.

Since such a fuel cell power generation plant is a device that directly generates electricity by electrochemically reacting hydrogen obtained by reforming fuel such as natural gas with oxygen in the atmosphere, its power generation efficiency is high. The efficiency is as high as 40 to 45 inches, and there is little decrease in efficiency even when operating at a partial load lower than the rated output, and the amount of pollutants such as sulfur oxides and nitrogen oxides is extremely low. In addition, because there are no rotating equipment such as large turbines or generators installed in thermal or nuclear power plants, there are fewer environmental restrictions such as less vibration and noise, and there are fewer location restrictions near demand areas. This eliminates the need for power transmission equipment and reduces power transmission losses.

As mentioned above, fuel cell power plants have the advantages of seeding, but they have the following problems.

That is, a fuel cell power generation plant generates a large amount of waste heat during power generation. Figure 3 shows the locations where exhaust heat is generated and the quality of the exhaust heat in a fuel cell power plant: hot water 8 from the fuel large-mouth steam condenser, hot water 9 from the air-electrode outlet steam-water separator, and the fuel cell cooling system. steam from the steam separator of the fuel cell, hot water from the intercooler for the air compressor installed to reduce the driving power of the air compressor installed to supply oxygen to the fuel cell, and air. Turbine exhaust 12 installed to drive the compressor
etc. Of these exhaust gases, other than the air compressor drive turbine exhaust gas 12, steam and hot water are directly or indirectly cooled to a low temperature by a cooling tower, and then recovered into the fuel cell power generation plant system by a heat exhaust device. (Some of it may be discharged outside the system without being collected.) We try to recycle and reuse it.

FIG. 4 shows, as an example, a configuration example of an exhaust heat recovery device for steam 1o from a steam separator of a fuel cell cooling system among the various kinds of exhaust heat mentioned above. In the figure, 2o is a steam separator that separates hot water from the saturated steam from the fuel cell 3 guided by the fuel cell cooling water return pipe 35, and 36.37 is a steam separator that separates hot water from the steam separator 20. A steam separator drain pipe 21 is a steam pipe that guides the steam separated by the steam separator 20 to be introduced as cooling water to the fuel cell 3 . 23
is a steam condenser, 27 is a cooling tower, and 29 is a cooling water circulation pump, which are cooling tower cooling water pipes 2B, 30, and 31.
Multiple connections are made to form a system for cooling the steam from the steam separator 2o. 22 is a steam condenser steam pipe that guides the steam from the steam separator 20 to the steam condenser 23; 24.26
is a steam condenser drain pipe for using water condensed and liquefied in the steam condenser 23 as cooling water for the fuel cell 3;
25 is a drain regulating valve that controls the drain flow rate. 32
34 is a reforming steam pipe, and 33 is a reforming steam flow rate regulating valve.

In such an exhaust heat recovery device, the cooling water used to cool the fuel cell 3 and heated by the fuel cell 3 to a temperature of about 190°C is returned to the fuel cell cooling water in a saturated state of steam and hot water. ) It is led to the steam separator 20 by the pipe 35, and is separated into steam and condensate in the steam separator 20. A part of the separated steam is transferred to the steam separator steam pipe 21, the reforming steam pipe 32.
34 and the reforming steam flow rate adjustment valve 33 to the fuel processing device 1 and used as reforming steam, all remaining steam becomes waste heat.

In the case of a single fuel cell power plant, this waste heat steam is passed through the steam condenser steam pipe 22 to the steam condenser 23.
It is condensed and liquefied by the cooling water guided by the cooling tower cooling water pipe 30, and guided into the fuel cell power generation plant system by the steam condenser drain pipe 24, 26 and the drain regulating valve 25, where it is circulated and reused. . In the steam condenser 23, the cooling water heated to a high temperature by the exhaust heat steam guided through the steam condenser steam pipe 22 is led to the cooling tower 27 through the cooling tower cooling water pipe 31, and in the cooling tower 21, the amount of heat is transferred to the atmosphere. After being discharged to the steam condenser 23 through the cooling tower cooling water pipe 28, the cooling water is led to the cooling water pump 29 through the cooling tower cooling water pipe 28, and the pressure of the cooling water is increased by the cooling water circulation pump 29. ing. On the other hand, the drain regulating valve 25 is for controlling the internal pressure of the steam separator 20 and the pressure of steam passing through the steam separator steam pipe 21 within a certain pressure range. To change the amount of exhaust heat steam from the steam separator 20, that is, the amount of steam condensed in the steam condenser 23, by operating in the closing direction when the pressure decreases and in the opening direction when the internal pressure increases. As a result, the internal pressure of the steam separator 20 is controlled within a certain pressure range.

By the way, the exhaust heat steam lid and temperature (amount and temperature of steam passing through the steam condenser steam pipe 22) from the steam separator 20 when a 100-class fuel cell power generation ground is operated with a 100-chi load is approximately 46×10 Yu/h. The saturated steam is about 180°C, and the temperature of the waste water (the temperature at which it passes through the steam condenser drain pipe 24) is about 165°C, so the amount of heat exchanged in the steam condenser 23, that is, the amount of heat released from the cooling tower 27 into the atmosphere, is The amount of waste heat generated is approximately 22.8 Xi O' kcal/h), and the thermal efficiency is relatively low for a fuel cell power generation plant.

[Purpose of the invention]

The present invention was made in consideration of the above circumstances, and
The purpose is to provide an exhaust heat recovery device for combined cycle power plants that can dramatically increase the thermal efficiency of fuel cell power plants and at the same time significantly reduce the fuel consumption rate of thermal power plants and improve overall plant thermal efficiency. It's about doing.

[Summary of the invention]

In order to achieve the above object, the present invention provides a fuel cell in which a fuel obtained in a fuel processing device is introduced into a fuel electrode, an oxidizer is introduced into an oxidizer electrode, and these are electrochemically reacted to generate electricity. In a combined power plant consisting of a power generation plant and a thermal power plant with a boiler water supply system,
The boiler feed water is introduced into the boiler water supply system of the thermal power plant through the first regulating valve, and the exhaust heat from the exhaust heat generating section in the fuel cell power plant is transferred to the second regulating valve and the exhaust heat exchanger. The exhaust heat from the fuel cell power generation plant after heating and temperature-raising the boiler feed water by introducing it through the drain tank and the drain tank is transferred from the drain tank to the drain tank.
1I14! A system is configured to recover heat back into the system of the fuel cell power generation plant via the II valve, and the temperature of the boiler feed water on the outlet side of the exhaust heat heat exchanger is compared with the set temperature, and based on the comparison result, the first A function of outputting a valve opening control signal for the regulating valve of the second regulating valve, comparing the exhaust heat pressure from the exhaust heat generating section with a set pressure, and outputting a valve opening control signal of the second regulating valve based on the comparison result. and a control device having a function of comparing the water level of the hot water stored in the drain tank with a set water level and outputting a valve opening control signal for the third regulating valve based on the comparison result, The present invention is characterized in that the amount of heat discharged from the fuel cell power generation gland is recovered to the boiler water supply system of the thermal power plant to improve overall plant thermal efficiency.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of the configuration of an exhaust heat recovery system for a combined cycle power plant according to the present invention. The same parts as in FIG. I will only describe it.

In the figure, 43 is a waste heat heat exchanger, 40 and 42 are waste heat steam pipes, and 41 is a steam regulating valve for heating feed water, through which the steam from the steam separator 20 is transferred to the waste heat heat exchanger 4.
I'm trying to lead to 3. In addition, 44 is a waste heat heat exchanger 4
147, the drain collected in the drain tank 45 is transferred to the drain tank 48, the drain tank water level adjustment valve 50, the exhaust heat drain pipes 47, 49, 51, and the steam separator. Drain pipe 3
8 into the fuel power plant system. Further, numeral 46 denotes a fludge and a steam recovery pipe that guide steam from the drain tank 45 to the waste heat exchanger 43.

On the other hand, the boiler feed water is guided to the waste heat heat exchanger 43 through the boiler water supply pipes 52 and 54 by the gain water flow regulating valve 53, and from there, the heat is recovered to the boiler feed water of the thermal power plant through the boiler water supply pipe 55. ing. (Also, 100
is a control device that controls the amount of exhaust heat and the amount of water supplied to the boiler, the details of which will be described later. 2(A) to 2(A) are block diagrams showing an example of the configuration of the control device 100 in the exhaust heat recovery device of a combined power generation plant configured as shown in FIG. 1.

〔table〕

Under the conditions of figure (a) and A1 in the table, the steam separator 2
The output signal of the pressure detector 56 in the 0 unit (4 to 20 mAD
c) is input to the setting device 57a to obtain a deviation signal for the pressure set value, and a control signal (4 to 20 mAD
c), the signal from the internal pressure detection 56 of the steam separator 20 is input to the alarm setting device 71a, and when the internal pressure of the steam separator 20 is below the specified value, the control signal is set to @-+d by the switch 59m.
is converted into an air signal (0.2 to 1.0 K97cm2fl) by an electro-pneumatic exchanger of 60h via an adder of 69, and the internal pressure of the steam separator of 20 is set based on the pressure setting value of a setting device of 57m. The drain regulating valve 25 is controlled so that the internal pressure of the steam separator 20 becomes a specified value.

Next, under the A20 condition in the table, when the signal from the steam separator 2° internal pressure detector 56 is greater than the set value of the alarm setting device at 71m, the contact operation signal in (2) is set by the switch at 59m. , the control signal of the PID controller of 58a @ -4p
6, and the drain adjustment valve 25 is controlled by making the analog signal of the flow rate detector 61 of the steam condenser steam pipe 22 linear by the square root calculator 62hK and inputting it to the setting device 57b.
Compare the minimum flow rate setting value and send the deviation signal to the PID controller 5.
8b, the control signal (4 to 20 mADc) flows to the adder 69b-)d by the switching signal of the switching device 59h.
Air signal (0,2~1.0
25 drain Fj4 regulating valve is controlled based on the minimum flow rate set value.

Furthermore, the signal from the pressure detector 68 of the exhaust heat recovery heat exchanger 43 is input to the alarm setting device 71b, and the pressure in the steam separator 20 is detected when the internal pressure of the exhaust heat recovery heat exchanger is lower than the set value pressure, that is, the internal pressure of the exhaust heat recovery heat exchanger is low. When the value of the device 56 (i) is equal to or higher than the specified value (2) with respect to the setting value of the alarm setting device 71h, the pressure control in the steam separator 20 is performed by obtaining a deviation signal from the pressure setting value with the setting device 571 and using the PID The control signal (from the controller 58m) is sent to the switch 59.
When the condition of the alarm setter 71b, which is the switching condition of the switch 59b, is below the set value, the control signal flows to c-+f, further flows to f-+h at the switch 59e, and the control signal flows to f-+h at the switch 59e. An electric signal (4 to 20 mAD
c) as air signal (0°2~1, 0ψ/cnt'fi)
The waste heat is converted to 1M, and the feed water heating steam valve 41 is controlled to supply the waste heat to the exhaust heat recovery heat exchanger 43, where it exchanges heat with the 1M Ira feed water for effective utilization.

In Table 43, the pressure detector 5 in the steam separator 20
6 When the detection signal is below the specified pressure for the alarm setting device 71a, the deviation signal for the pressure setting value is set to P using the setting device 57&.
The control signal of the IDFI meter 58a is set to 1-* by the switch 59h.
d, an electric signal (4 to 20 mADC) is converted to an air signal (0.2 to 1.0
kli/cm211), and the drain IA regulating valve 25 is controlled so that the pressure in the steam separator 20 becomes a specified pressure based on the setting value of the setting device 51a.

Furthermore, the signal of the pressure detector 68 of the exhaust heat recovery heat exchanger 43 is compared with the set value by the alarm setting device 7Jb, and when the signal is equal to or higher than the set value (i.e., the internal height of the exhaust heat recovery heat exchanger), the pressure of the setting device 571 is set. The control signal of the PID controller 581 converts the setting deviation signal into an electric signal (
4 to 20 mADc) to the air signal (0,2 to 1.0
kg152N) IC is converted to control the water heating steam valve 4 of the vessel so that the internal pressure of the exhaust heat recovery heat exchanger 43 becomes below the specified value.

Under the A40 condition in the table, the internal pressure of the steam separator 20 is higher than the value set by the alarm setting device 11 & (i.e. the internal pressure of the steam separator 2 is high) (1), and the internal pressure of the exhaust heat recovery heat exchanger 43 is alarmed. When the condition is equal to or higher than the set value by the setter 7Jb (that is, the internal pressure of the exhaust heat recovery heat exchanger), the internal pressure detection signal of the steam separator 20 is determined by the setter 57a, and the deviation signal from the pressure set value is determined by the PID adjustment. A total of 58 & control signals are provided by switch 5.
At 9a, the flow is switched from a to C and at C-+@ at the flow switch 59b.
The deviation from the minimum flow rate setting signal is obtained using the IJ near setter 57b, and the control signal of the PID controller 58b is sent to the electro-pneumatic converter by adding the control signal added by the flow adder 69 to l)-*d using the switch 591L. 60&′α electric signal
4~20 mADC) to air signal (0,2~1.0/
cm2g), and the drain regulating valve 25 is controlled so that the internal pressure of the steam separator 20 becomes a specified value.

Next, in the figure axis), the flow rate of the reforming steam pipe 34 is determined by the output signal of the flow rate detector 63 installed in the reforming steam pipe 34 [4 to 20
mADC) is linearized by the square root calculator 62b, a signal is output to the setting device 57c to obtain a deviation signal with respect to the load setting value, and a control signal (4 to 2
0 mADc) to a predetermined value (0,2~
The reforming steam flow rate control valve 33 is controlled so that the flow rate of the reforming steam pipe 34 becomes a specified value based on the load setting value of the setting device 57c. .

In addition, in the same figure (,), the steam flowing through the waste heat steam pipe 42 is supplied to the waste heat heat exchanger 43, where the boiler water supply pipe 52
The voltage signal from the temperature sensor 64 installed at the outlet of the waste heat heat exchanger 43 is transferred to the temperature converter 6.
5 converts it into a predetermined (4 to 20 mADc) signal and outputs it to the setting device 57d to obtain a deviation signal with respect to the temperature setting value,
A control signal (4 to 20 mAD
C) to a predetermined air signal (0
, 2-1. -9/cm2g), and the boiler feed water flow rate regulating valve 53 is controlled so that the outlet temperature of the boiler feed water pipe 55 becomes a specified value based on the temperature setting value of the setting device 57d.

Furthermore, in FIG. 4(d), the hot water heat-exchanged by the exhaust heat exchanger 43 is stored in a drain tank 45.

The excess amount of hot water stored in this drain tank 45 is detected by a water level detector 66 installed in the drain tank 45 (4 to 20
mADC) is output to the setting device 576 to obtain a deviation signal from the water level set value, and the HD controller 586
The control signal (4 to 20 mADc) is sent to the electro-pneumatic converter 60e via the limiter (upper and lower limiter) 67 to a predetermined air signal (0.2 to 1.0 mADc).
By converting the K signal, the drain tank water level adjusting valve 5o is controlled to bring the water level of the drain tank 45 to a specified value based on the water level set value of the setting device 57e.

Next, the functions and effects of the combined power generation plant with this configuration will be described. First, in conventional thermal power plants, the gain water extracted from the condenser is heated and raised in temperature by the heated steam from the steam turbine in a low-pressure heater, and then flows into the deaerator. In this example, as shown in Fig. 1, the exhaust heat of the fuel cell power generation plant is used without using the heated steam from the steam turbine (that is, the heating steam valve and the low-pressure heater drain valve on the thermal power plant side are fully closed). is used to increase the temperature of the boiler feed water.

That is, when recovering waste heat (steam) from a fuel cell power plant to the boiler water supply system of a thermal power plant, first open the gain water supply flow rate adjustment valve 53 and transfer the waste heat through the gain water supply pipes 52 and 54. After the boiler feed water flows through the exchanger 43, the feed water heating steam valve 41 is opened and the waste heat steam of the fuel cell power generation plant is guided to the waste heat heat exchanger 43 through the waste heat steam pipes 40 and 42, where it is condensed and liquefied. . This liquefied drain is transferred to the drain tank 4 through the exhaust heat drain pipe 44.
After recovering 54C, it is led to the drain pump f4B through the exhaust heat drain pipe 47, and after increasing the pressure with the drain pump 48, the drain tank water level adjustment valve 50 and the exhaust heat drain pipe 49.51
Then, it is recovered into the fuel cell power generation plant system through the steam separator drain pipe 38 and recycled for reuse. Note that the steam separated by the steam separator 20 is saturated steam as described above, and since it flows into the waste heat heat exchanger 43 in a substantially saturated steam state, it is condensed in the waste heat heat exchanger 43 by the gain water supply.・
The liquefied drain is also almost a saturated liquid. Therefore, from the drain flowing into the drain tank 45, the exhaust heat drain pipe 4
4, flash steam is generated due to pressure loss when passing through the boiler, so in this embodiment, a flood and steam recovery pipe 46 are provided to recover the flash steam to the waste heat exchanger 43 and reliquefy it with boiler feed water. . In addition, the gain water supply pipe 5
The gain feed water led to the waste heat heat exchanger 43 by the waste heat heat exchanger 43 is heated and heated by the waste heat steam from the steam separator 20 led by the waste heat steam pipe 42, and the heat is recovered to the gain feed water of the thermal power plant. Ru.

At this time, since the exhaust heat (steam) from the fuel cell power plant decreases in the steam condenser 23, the operation of the cooling tower 270, the fan drive motor (not shown) and the cooling water circulation bond 29 may be stopped. , the in-house power can be reduced accordingly.

On the other hand, in a 100j# class fuel cell power plant, M
As mentioned above, the amount of waste heat in the form of air is about 22.8 x 10' kcal/h, but for example, 220 MW to 700 MW.
When calculating the annual reduction in fuel costs for a thermal power plant when all of this waste heat is recovered in the boiler water supply system of a thermal power plant, it is assumed that the efficiency of the boiler installed in the thermal power plant is 90%, Assuming that the plant load factor is 100ch and the plant utilization rate is 70%, the annual thermal power generation will be '11! The fuel consumption of the engine decreases by approximately 3.7 x I Okcal (approximately 3,000 tons). Here, the fuel cost is 6 yen 7103 kcal
Assuming this, the annual reduction in fuel costs will be approximately 220 million yen.

From the above, if all the waste heat in the form of steam and hot water in a 100 MW class fuel cell power plant is recovered to the female water supply system of the thermal power plant, the cost of fuel burned at a gain will be approximately 2. You can save only 200 million yen. Naturally, as the scale of a fuel cell power generation plant increases, the amount of exhaust heat increases in proportion to the scale, and the amount of heat recovered to the thermal power plant also increases. As the fuel consumption rate decreases, the reduction in annual fuel costs increases. In addition, the thermal efficiency of the 100Mw class fuel cell power generation plant using only power generation is approximately 46%, but if the total amount of waste heat in the form of steam is recovered to the thermal power plant, the thermal efficiency of the fuel cell power generation plant will be approximately 46%. This is approximately 58%. In other words, it is possible to increase the thermal efficiency of a fuel cell power generation plant and at the same time reduce the fuel consumption rate of a thermal power generation plant, thereby increasing the thermal efficiency.As a result, the overall plant thermal efficiency of the entire combined cycle power plant is improved, resulting in energy savings. It is possible to obtain a plant that can contribute to

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be similarly implemented in the following manner.

(a) In the above example, exhaust heat steam from a fuel cell power generation plant is recovered to one low-pressure heater of a thermal power plant. However, if the amount of exhaust heat steam is large, multiple low-pressure heaters or high-pressure heaters are used to recover heat. It may be collected.

伽) In the above example, heat was recovered directly from waste heat steam to the low-pressure heater of the thermal power plant, which is the existing equipment, but a new heat exchanger was installed in a position that bypassed the existing equipment to recover heat indirectly. It's okay.

Other 1 The present invention can be implemented with various modifications without changing the gist thereof.

〔Effect of the invention〕

As explained above, according to the present invention, exhaust heat from the exhaust heat generation section in the fuel cell power plant is transferred to the boiler water supply system of the thermal power plant, into which boiler feed water is introduced via the first regulating valve. The boiler feed water is heated and heated through the second regulating valve and the exhaust heat exchanger, and the exhaust heat from the fuel cell power generation plant after the heat exchange is transferred from the drain tank to the third drain tank. A system is configured to recover heat back into the system of the fuel cell power generation plant via a regulating valve, and the temperature of the feed water on the outlet side of the waste heat heat exchanger is compared with the set temperature, and based on the comparison result, the 1st
A function of outputting a valve opening control signal for the regulating valve of the second regulating valve, comparing the exhaust heat pressure from the exhaust heat generating section with a set pressure, and outputting a valve opening control signal of the second regulating valve based on the comparison result. and a control device having a function of comparing the water level of the hot water stored in the drain tank with a set water level and outputting a valve opening control signal for the third regulating valve based on the comparison result. Therefore, we have developed an exhaust system for combined cycle power generation plants that can dramatically increase the thermal efficiency of fuel cell power generation plants and at the same time significantly reduce the fuel consumption rate of thermal power generation glands, improving overall plant thermal efficiency and contributing to energy savings. Heat recovery equipment can be provided.

[Brief explanation of drawings]

Figure 1 is a configuration diagram showing one embodiment of the present invention, Figure 2 (-)
- (d) are block diagrams showing details of the control device in Fig. 1, Fig. 3 is a block diagram showing a fuel cell power generation plant, and Fig. 4 is a block diagram showing an exhaust heat recovery device of a conventional fuel cell power generation plant. It is. 1... Fuel processing device, 2... Air processing device, 3...
・Fuel cell, 4... Orthogonal conversion device, 5... Converter transformer, 6... Breaker, 7... Power system, 8, 9
゜11...Hot water exhaust heat, 10...Steam exhaust heat, 12...
- Turbine exhaust, 20... Steam separator, 21... Steam separator steam pipe, 22... Steam condenser steam pipe, 23...
...Steam condenser, 24.26...Steam condenser drain pipe, 25...Drain adjustment valve, 27...Cooling tower, 28°30.31...Cooling tower cooling water pipe, 29... Cooling water circulation tank, 32.34...Steam pipe for reforming, 33...
Reforming steam flow rate adjustment valve, 35...Fuel cell cooling water return pipe, 36.37.38...Steam separator drain pipe, 40.
42...Exhaust heat steam pipe, 41...Steam regulating valve for heating water supply, 43...Exhaust heat heat exchanger, 44.47°49.51
...Exhaust heat drain pipe, 45...Drain tank, 46.
...Flash steam recovery pipe, 48...Drain tank,
50...Drain tank water level? Aa valve. 52.54.55...Boiler water supply pipe, 53...Boiler water supply flow rate adjustment valve, 56.68...Pressure detector, 57
a, 57 b, 57 c, 57 d,
57 'Y'''full gauge, 5B&, 58b, 58c
, 511d, 58e. SSt...PID controller, 59h, 59b, 59c.
...Switcher, 60*, 60b, 60e, 6ow. 60. ...Electro-pneumatic converter, 61.63...Flow rate detector, 62m, 62b...Square root calculator, 64...Temperature detector, 65...Temperature converter, 66...Water level detection vessel,
67...Limiter, 69...Adder, 70...Signal amplifier, 71a, 7lb...-Alarm setting device, 100...Control device. Applicant's agent Patent attorney Takehiko Suzue (b)
(C) (d) Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A fuel cell power generation plant in which fuel obtained from a fuel processing device is introduced into the fuel electrode and an oxidizer is introduced into the oxidizer electrode, and these are electrochemically reacted to generate electricity. Thermal power generation has a boiler water supply system. In a combined power generation plant consisting of a plant, exhaust heat from the exhaust heat generating section in the fuel cell power generation plant is transferred to the boiler water supply system of the thermal power plant into which boiler feed water is introduced via a first regulating valve. The boiler feed water is heated and raised in temperature by being introduced through a regulating valve and an exhaust heat heat exchanger, and the exhaust heat from the fuel cell power generation plant after this heat exchange is passed through a drain tank and a drain pump to a third regulating valve. A system for recovering heat is configured in the system of the fuel cell power generation plant again through the system, and the boiler feed water temperature on the outlet side of the waste heat heat exchanger is compared with a set temperature, and based on the comparison result, the first regulating valve a function of outputting a valve opening control signal for the second regulating valve; a function of comparing the exhaust heat pressure from the exhaust heat generating section with a set pressure and outputting a valve opening control signal for the second regulating valve based on the comparison result; and a control device having a function of comparing the water level of the hot water stored in the drain tank with a set water level and outputting a valve opening control signal for the third regulating valve based on the comparison result. Exhaust heat recovery equipment for combined cycle power generation plants.