JPS61191825A - Fuel cell power generation type hot water supplier for space cooling and heating - Google Patents

Abstract

PURPOSE:To make it possible to perform power generation and hot water supply for space cooling and heating by a single energy source of a fuel gas by separating hydrogen occluded in a hydrogen storage alloy to supply the same to the fuel cell power generating device in an emergency in which a hydrogen gas is impossible to obtain from a reformer. CONSTITUTION:In a case where a natural gas 10 becomes impossible to be supplied, a contact 43 is opened and a contact 48 is closed and an emergency power is supplied from a battery 46. Then, the opening degree of a pressure reducing valve 22 is adjusted to reduce the pressure within a hydrogen preserving device 18 to a predetermined value or less and to separate hydrogen from a hydrogen storage alloy. Then, a hydrogen gas is fed to a fuel cell power generating device 14. In a case where the quantity of the hydrogen gas passing through a pipeline 18G is insufficient even when the pressure reducing valve 22 is fully opened, valves 26VA and 16VB are closed but valves 26VC and 16VD are opened, and a contact 42A is closed. As a result, a heat exchanger 40 for heating is heated, and a circulation pump 42 is turned ON. The interior of the hydrogen preserving device 18 is heated, and the hydrogen separation speed becomes large. Thus, the quantity of the hydrogen gas supplied to the fuel cell power generating device is increased.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fuel cell that generates electricity using fuel gas such as natural gas, coal gas, or methanol, and also performs air conditioning, heating, hot water supply, etc. by effectively utilizing exhaust heat. Related to power generation heating, cooling, and hot water supply equipment.

[Conventional technology] Conventionally, it has been necessary to have a separate power generation device, typically a diesel generator, in order to cope with emergencies where fuel gas cannot be supplied to the fuel cell power generation device due to a disaster or accident. there were.

[Problems to be Solved by the Invention] An object of the present invention is to obtain a fuel cell power generation, heating, cooling, and hot water supply system that is capable of generating electricity, heating, cooling, and hot water supply only with the fuel cell power generation system even in an emergency.

[Means for Solving the Problems] The fuel cell power generation cooling, heating, and hot water supply system according to the present invention includes a reformer that reformes fuel gas to generate rich hydrogen, and a reformer that generates direct current using the rich hydrogen. a hydrogen storage device that stores a portion of the rich hydrogen in a hydrogen storage alloy, devolatilizes the stored hydrogen in an emergency, and supplies it to the fuel cell; and a hydrogen storage device that generates steam using the combustion heat of fuel gas. It has a boiler and an air-conditioning/heating/hot-water supply system that uses exhaust heat from the fuel cell power generator and steam from the boiler.

[Operation] Under normal conditions, rich hydrogen is generated from fuel gas in a re-former, and this rich hydrogen is used to generate electricity by a fuel cell power generation device. Further, when the generated electric power is under low load, a portion of the rich hydrogen is stored in the hydrogen storage alloy of the hydrogen storage device. This storage is performed by keeping the temperature of rich hydrogen below a certain value or the pressure of rich hydrogen above a certain value. A part of the fuel gas is also used in a boiler. The air conditioning, heating, and hot water supply system uses exhaust heat from the fuel cell power generation system, and steam from the boiler is used to make up for the insufficient exhaust heat.

When fuel gas cannot be supplied due to a disaster or accident, that is, in an emergency, the hydrogen stored in the hydrogen storage alloy is devolatilized, and this hydrogen is used to generate electricity in a fuel cell power generation device. This devolatilization is performed by keeping the temperature of hydrogen above a certain value or the pressure of hydrogen below a certain value.

[Example] An example of the fuel cell power generation air conditioning/heating/water supply apparatus according to the present invention will be described with reference to the drawings.

Natural gas lO, which is a single energy source, is supplied to the reformer 12 through a pipe 10G. The reformer 12 reforms the natural gas 1o to generate rich hydrogen gas. This hydrogen gas is transferred to the fuel cell power generator 1 via pipe 12G.
4. Fuel cell power generation device 1
4 uses this hydrogen gas and oxygen in the air to generate direct current.

The pipe 12G is branched, and the pipe 12G is connected to the pipe 12G via the suction valve 16.
At A, hydrogen gas is supplied to the hydrogen storage device 18. The hydrogen storage device 18 is made of a hydrogen storage alloy 1 such as iron.
Equipped with a titanium alloy, it is possible to occlude or devolatilize hydrogen by changing temperature and pressure conditions. The inside of the hydrogen storage device 18 can be pressurized by a compressor 2o.

Hydrogen stored in the hydrogen storage device 18 is supplied to the fuel cell power generation device 14 through a pipe 18G via a pressure reducing valve 22.

Exhaust heat steam, exhaust heat high temperature water (approximately 80°C), and exhaust heat low temperature water (approximately 40°C) generated as cooling water in the fuel cell power generation device 14
is used as a heat source for heating, cooling, and hot water supply.

That is, the exhaust heat steam is transferred to the pipes 14S and 14 that are connected in sequence.
It is supplied to the absorption chiller 23 through SA and 14SB,
Pipes 14SC and 10 sequentially connected to the piping 14SA
The water is supplied to the hot water heat exchanger 24 for heating through the SD, and is further supplied to the hot water storage tank 26 through the piping 143E connected to the piping 143C.

A pipe 253 for supplying steam from the boiler 25 is connected to the pipe 14SA, and the steam from the boiler 25 is used when exhaust heat steam is insufficient. The fuel for this boiler 25 is the natural gas 10 supplied through a pipe 10GA branched from the pipe LOG.

The grass that has passed through the absorption refrigerator 23, the hot water heat exchanger 24, and the hot water storage tank 26 becomes water droplets, which are respectively connected to the piping 23D.

The water passes through 24D and 26D, joins at pipe 21D, is collected in hot well tank 21, and then supplied to boiler 25, and a portion is reused as cooling water for fuel cell power generation device 14.

The exhaust heat high temperature water generated by the fuel cell power generation device 14 passes through the sequentially connected pipes 14H and 114HA, absorbs heat in the hot water heat exchanger 24, becomes low temperature, and passes through the pipes 24L and 24LA%.
24LB, and if necessary, is further cooled in a cooling tower 49, passes through a pipe 49L, and is reused as cooling water for the fuel cell power generation device 14. In addition, the pipe 14H has a pipe 1
4HB is connected and led to the hot water storage tank 26, and the waste heat high temperature water absorbs heat in the hot water storage tank 26, becomes low temperature water, and is sent to the piping 26.
It passes through L and joins with the low temperature water in the pipe 24L, and is used as cooling water for the fuel cell power generation device 14, similar to the waste heat high temperature water for heating the hot water heat exchanger 24.

In addition, the waste heat low temperature water generated by the fuel cell power generation device 14 passes through the pipe 14L, absorbs heat in the hot water preheating exchanger 28, becomes lower temperature, passes through the pipe 28L, and passes through the pipe 24L.
It is combined with the low-temperature water inside and used as cooling water for the fuel cell 14 in the same way as the waste heat high-temperature water for heating the hot water heat exchanger 24.

Cold water for air conditioning is cooled by the absorption chiller 23, and is supplied to the air conditioner through a pipe 23C via a cold water supply header 30. That is, the cold water coil in the air conditioner absorbs heat, passes through the pipe 23L via the cold water header 32, and returns to the absorption refrigerator 23 for circulation. In addition, a part of the chilled water cooled by the absorption chiller 23 passes through the pipe 23CA at night when the cooling load of the building is low, lowers the temperature inside the hydrogen storage device 18, and returns to the pipe 23LA for circulation. ing. (During hydrogen storage operation) Hot water for heating is heated by the hot water heat exchanger 24, and is supplied to the air conditioner through the pipe 24H via 34. In other words, the heat is radiated by the hot water coil inside the air conditioner, and the hot water retan header 36
The hot water is circulated back to the hot water heat exchanger 24 through piping 24L via the hot water heat exchanger 24.

Also, makeup water is supplied to the hot water preheating exchanger 28, and the makeup water preheated by the hot water preheating exchanger 28 is supplied to the hot water storage tank 26 through the piping 28L, is further heated in the hot water storage tank 26, and is pumped into the circulation pump. Hot water is supplied through piping 26H via piping 38, and excess hot water is returned to hot water storage tank 26 through piping 26L. The open/closed state of the valve at this time is valve 26VA.
, 26VB is open, and valve 26VC126VD is closed. In addition, the hot water passing through the pipe 26H is transferred to the branched pipe 26H.
The heat is absorbed in the heating heat exchanger 40 through the HA, and the heat is absorbed into the pipe 2.
It passes through 6LA and joins with the hot water that passes through pipe 26L. The open/closed states of the valves at this time are valves 26VA and 2.
6VB is closed, and valves 26VC126VD are open.

Hydrogen is released from the hydrogen storage device 18 by heating the hydrogen storage device 18 with hot water heated in the heating heat exchanger 40. That is, the hot water passes through the piping 40H via the circulation pump 42. After heating the inside of the hydrogen storage device 18, it passes through the pipe jOL and returns to the inside of the heating heat exchanger 40 for circulation. Note that this heating heat exchanger 40
Alternatively, the inside of the hydrogen storage device 18 may be directly heated from the hot water tank 26 using the circulation pump 38.

Next, during normal operation, the direct current generated by the fuel cell power generation system N14 flows through the wiring 14E via the contact 43, and the inverter 44
The current is converted into alternating current and supplied to the circulation pump 38. In addition, when the power load is small, the direct current generated by the fuel cell power generation device 14 is transferred to the wiring 14 via the contact 45.
It flows through EA and can be charged at Yatsuteri 46. In an emergency such as when the fuel cell goes down, the battery 46 can supply power to the inverter 44 through the wiring 14EB via the contact 48. The AC output from the inverter 44 is first applied to the contacts 42 to supply hydrogen to the fuel cell.
Power is supplied to the pump 42 through A, and power is supplied to the pressure reducing valve 22 through contact 22A. It also supplies power to other necessary electrical equipment as a safety power source.

Next, the detailed configurations of the reformer 12 and the fuel cell power generation device 14 will be explained according to FIG.

The fuel cell 70 includes a fuel electrode 70A, an air electrode 70B, and a heat exchanger 70C that cools the fuel cell 70.

Natural gas is reformed by a reformer 72 to produce rich hydrogen, cooled by a fuel gas cooler 74, and then hydrogen gas is separated by a fuel gas steam water separator 76 and supplied to the fuel electrode 70A. It has become. Fuel electrode 70A
The hydrogen gas that did not react with oxygen is supplied to the reforming furnace 72 and used as fuel for the reforming furnace 72. The returning high temperature water is heated to approximately 80" by the fuel gas cooler 74.

The air is compressed by a low-pressure air compressor 78, and the heat generated by the compression is absorbed by a compressor intercooler 80.
Furthermore, the air electrode 70 is pressurized by a high-pressure air compressor 82.
B is supplied. The air that has not reacted with hydrogen at the air electrode 70B is heat-absorbed by the air electrode outlet gas cooler 84, and then its moisture is removed by the air electrode outlet gas steam water separator 86, and then supplied to the reforming furnace 72. Hydrogen gas from the fuel electrode 70A is burned. A portion of the returned low-temperature water also passes through the air electrode outlet gas cooler 84 and is heated to about 40@C.

The excess steam generated from the battery circulation water/steam water tank 96 is
It is cooled by the surplus steam condenser 94 and becomes condensed water.

The return steam condensed water is supplied to the battery circulating water/steam separator 96 . The cooling water in the battery circulation water/steam separator 96 is transferred to the heat exchanger 7.
It is heated through 0C and turned into steam, which is used in air conditioning, heating, and hot water supply systems.

A part of this steam is also supplied to the reforming furnace 72. The piping passing through the surplus steam condenser 94 forms a loop, and part of the hot water heated by the surplus steam condenser 94 is used as high-temperature water for the air conditioning system, and the rest is used in a part of the loop. It is cooled in the formed cooling tower 97, merges with a portion of the returned low-temperature water, and flows to the surplus steam condenser 94.

The combustion gas in the reforming furnace 72 is discharged from the exhaust tower 92 to the atmosphere via a high pressure exhaust turbine 88 and a low pressure exhaust turbine 90.

In this way, waste heat low temperature water, waste heat high temperature water, and waste heat steam are each independently generated.

Next, the operation of the first embodiment configured as described above will be explained with reference to the control flowcharts shown in FIGS. 3 to 6.

FIG. 3 shows a flow chart of hydrogen gas supply, and in the initial state, the suction valve 16 and the pressure reducing valve 22 are closed. When the natural gas 10 can be supplied (step 200), hydrogen gas is generated in the reformer 12 (step 202), and then when the power on the load side of the fuel cell power generation device 14 is higher than a certain value T1 and the load is high. (Step 204), to supply hydrogen gas to the fuel cell power generation device 14 without opening the intake valve 16 (Step 206),
Return to step 200. If this power is less than a certain value P, the load is low, and the cooling is low load (step 208),
When the amount of hydrogen stored in the hydrogen storage device 18 is less than a certain value (step 210), the intake valve 16 is not opened (step 212), and the hydrogen storage alloy in the hydrogen storage device 18 is stored in an absorption refrigerator. 23 (step 214), the temperature T in the hydrogen storage device 18 is a constant value T1
In this case, the inside of the hydrogen storage device 18 is pressurized by the compressor 20 (step 218), and when T<T1, hydrogen is stored in the hydrogen storage alloy without pressurization (step 220), and the process returns to step 210.

Hydrogen is stored in this way, and when it is determined in step 210 that the amount of hydrogen stored in the hydrogen storage device 18 is above a certain value, the suction valve 16 is closed and the hydrogen storage alloy is stored in the absorption refrigerator 23. Along with stopping cooling (step 2
24) Stop pressurizing the compressor 20 (step 226) and then return to the main routine.

In step 200, it is determined that the natural gas 10 cannot be supplied,
And if power supply is required (step 228),
Emergency power is supplied from the battery 46 by opening the contact 43 and closing the contact 48 (step 230). Next, the opening degree of the pressure reducing valve 22 is adjusted to lower the pressure in the hydrogen storage device 18 to a certain value or less, devolatilizing hydrogen from the hydrogen storage alloy (step 232) and supplying hydrogen gas to the fuel cell power generation device 14 (step 232). Step 234), then the fuel cell power generation device 14 starts supplying power, Step 236) opens the contact 45 to stop power supply from the battery 46 (Step 238), and the hydrogen gas flow rate passing through the pipe 18G is adjusted to the pressure reducing valve. 22
If the amount is insufficient even if fully opened, the amount is below a certain level (step 240), close valves 28VA and 26VB, and close valve 26VC.
.

26VD is opened and contact 42A is closed (Step 2
42), whereby the heating heat exchanger 40 is heated (
Step 244), the circulation pump 42 is supplied with power and turned on (step 246), and the inside of the hydrogen storage device 18 is heated, the hydrogen desorption rate increases, and the amount of hydrogen gas supplied to the fuel cell power generation device 14 increases. (step 250
), hydrogen storage device 1 until natural gas 10 can be supplied.
Continuing to supply hydrogen gas from B to the fuel cell power generation device 14 (step 254), when the supply of natural gas 10 becomes possible, stop heating the hot water in the hydrogen storage device 18 (step 256), and reducing the pressure. Close the valve 22 (
step 258).

Although not shown in the drawings, the piping 12GA and the piping 18G are provided with flow meters, the hydrogen storage device 18 is provided with a thermometer and a pressure gauge, and the fuel cell power generator 14 is provided with a wattmeter. ing.

Next, FIG. 4 shows a control flowchart of steam supplied to the absorption chiller 23, and the fuel cell power generation device 1
Step 300), if this steam is sufficient, ie.

If the temperature detected by a thermometer (not shown) installed in the absorption chiller 23 after a certain period of use becomes less than the fixed value T2 (step 302), the absorption chiller 23 is turned on without using steam from the boiler 25. If there is a request for steam from the refrigerator 23, the process returns to step 300 (step 304), and if the temperature is above the constant value T2, when the natural gas 10 is available (step 306), the process returns to step 300 (step 304). Absorption chiller 23 also uses steam (step 308)
When there are no more requests for steam, the process returns to the main routine and waits for the next request.

Therefore, the exhaust heat of the fuel cell power generation device 14 is effectively used by the absorption refrigerator 23.

Next, FIG. 5 shows a flowchart for controlling heat absorption in the hot water heat exchanger 24, and the exhaust heat high temperature water is transferred to the hot water heat exchanger 24.
In step 400), if the exhaust heat high temperature water from the fuel cell power generation device 14 is sufficient, that is, after a certain period of use, a thermometer (not shown) installed in the hot water heat exchanger 24 If the detected temperature is equal to or higher than the fixed value T3 (step 402), steam is not used. If the hot water outlet temperature of the hot water heat exchanger 24 is lower than the fixed value, the process returns to step 400 (step 404). If the temperature at step 402 is less than the constant value T3,
Step 40: Check whether there is excess waste heat steam.
6) If there is any remaining waste heat steam, the next step is to use the waste heat steam (step 408). If this waste heat steam is insufficient, that is, the temperature of the hot water heat exchanger 24 remains constant after being used for a certain period of time as described above. If it is less than the value T (step 41゛0)
, when natural gas 10 is available (step 412
), steam from the boiler 25 is also utilized (step 414
).

Therefore, the exhaust heat of the fuel cell power generation device 14 is effectively used in the hot water heat exchanger 24.

Next, FIG. 6 shows a control flowchart for the hot water storage tank 26 and the hot water preheating exchanger 28. Initially, the exhaust heat low temperature water from the fuel cell power generation device 14 is used to supply makeup water in the hot water preheating exchanger 28. Preheat (step 500).

Therefore, even the waste heat low temperature water from the fuel cell power generation device 14 can be effectively used.

The preheated hot water in the hot water exchanger 28 is supplied to the hot water storage tank 26 (step 502), and then, if there is excess waste heat high temperature water (step 504), the waste heat high temperature water is supplied to the hot water storage tank 26. (step 506), and if this heating is insufficient (step 508).
), check whether there is any surplus heat steam (step 516), and if there is, heat the hot water in the hot water tank 26 with the waste heat steam from the fuel cell power generation device 14 (step 516).
12) If this heating is sufficient (especially in the summer), that is, if the temperature detected by a thermometer (not shown) installed in the hot water storage tank 26 after a certain period of use reaches a certain value T4 or higher, , the steam from the boiler 25 is not used (step 514); if the exhaust heat steam is insufficient, the steam from the boiler 25 is also used when natural gas lO is available (step 516), and heating is performed. Continue heating with this steam until sufficient (steps 518, 520).

Therefore, the exhaust heat in the fuel cell power generation device 14 is transferred to the hot water storage tank 2.
6 and the hot water preheating exchanger 28.

Next, regarding power supply, normally the contact 43 is closed and the DC generated by the fuel cell power generator 14 is converted into AC by the inverter 44 to supply power to each device. When the load is light, the contact 45 is closed to charge the battery 46. When the fuel cell power generator 14 fails and a power outage occurs, the contact 43 is opened and power is supplied only from the battery 46 to the safety equipment.

Next, a second embodiment of the present invention will be described according to FIG.

In this second embodiment, the equipment is larger than the first embodiment, and a cold water vertical heat storage tank 50 is provided in the cooling circulation path.
A hot water vertical heat storage tank 52 is provided in the heating circulation path. In addition, in order to recover the heat possessed by the return water for cooling and the return water for heating and supply this heat to the hot water preheating exchanger 28,
A full-power reversible heat recovery air source heat pump 60 is provided, which includes a hot water heat exchanger 58, a main heat exchanger 56, and an auxiliary heat exchanger 54 for supplying cold water or hot water to a vertical heat storage tank. Other points are the same as in the first embodiment.

[Effects of the Invention] The fuel cell power generation air conditioning/heating and hot water supply system according to the present invention is equipped with a hydrogen storage device equipped with a hydrogen storage alloy, and in an emergency when hydrogen gas cannot be obtained from the rifoma, the hydrogen stored in the hydrogen storage alloy can be used. Since the gas is devolatilized and supplied to the fuel cell power generation device, it has the excellent effect of being able to perform power generation, heating, cooling, and hot water supply using a single energy source of fuel gas.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the fuel cell power generation cooling, heating, and hot water supply system according to the present invention, FIG. 2 is a block diagram showing details of the reheater and fuel cell power generation system shown in FIG. FIG. 6 is a control flowchart, and FIG. 7 is a block diagram showing the configuration of a second embodiment of the present invention. 10-Natural gas, 12--Reformer, 14--Fuel cell power generator, 16--Suction valve, 18--Hydrogen storage device, 20--Compressor, 22--Reducing valve, 23... φ absorption refrigerator, 24... Hot water heat exchanger. 25. Boiler, 26. Hot water storage tank, 28. Hot water preheating exchanger.

Claims (1)

[Claims] (1) A reformer that reforms fuel gas to generate rich hydrogen, a fuel cell power generation device that generates direct current using the rich hydrogen, and a hydrogen storage alloy that stores a portion of the rich hydrogen in case of an emergency. A hydrogen storage device that devolatilizes hydrogen and supplies it to a fuel cell, a boiler that generates steam using the combustion heat of fuel gas, and an air-conditioning, heating, and water-heating device that uses the exhaust heat of the fuel cell power generation device and the steam of the boiler. What is claimed is: 1. A fuel cell power generation air conditioning, heating, and hot water supply device.