JPS61191824A - Fuel cell power generation type hot water supplier for space cooling and heating - Google Patents

Abstract

PURPOSE:To improve the efficiency of energy use by effectively utilizing the waste heat of the fuel cell power generating device for the hot water supplier for space cooling and heating device. CONSTITUTION:An exhaust heat steam 4 generated as cooling water in a fuel cell power generating device 14 is fed to an absorption type freezer 23 via pipelines 14S, 14SA and 14SB, and also fed to a space heating hot water heat exchanger 24 via pipelines 14SC and 10SD, and further to a hot water storage tank 26 via a pipeline 14SE. Exhaust heat high hot water is fed through pipelines 14H and 14HA to a hot water heat exchanger 24 wherein the high hot water is absorbed of its heat and assumes a low temperature, and further passes through pipelines 24L, 24LA, and 24LB. Further, if necessary, it is cooled in a cooling tower 49, and is reutilized as cooling water of the fuel cell power generating device 14 via a pipeline 49L. Exhaust heat low hot water is fed through a pipeline 14L to a supply hot water preheat exchanger 28 wherein it is absorbed of its heat. Then, it assumes a lower temperature and passes through a pipeline 28L and amalgamates with low temperature water within the pipeline 24L and is utilized as cooling water for the fuel cell 14.

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] In devices that use the exhaust heat of fuel cell power generation equipment for heating, cooling, and hot water supply, the amount of exhaust heat is sufficient, but the exhaust heat temperature is only about 45°C, and the thermal efficiency is poor, making it difficult to utilize the exhaust heat effectively. It was difficult to use. Furthermore, when there is surplus power (when not in use or under light load), neither the power nor the waste heat can be used effectively, resulting in poor energy usage efficiency.

[Problems to be Solved by the Invention] An object of the present invention is to obtain a fuel cell power generation air conditioning, heating, and hot water supply system that effectively utilizes the exhaust heat of the fuel cell power generation system in the air conditioning, heating, and water supply system to improve energy use efficiency. shall be.

[Means for Solving Problems m] The fuel cell power generation air conditioning, heating, and hot water supply system according to the present invention includes a reformer that reformes fuel gas to generate rich hydrogen, and a fuel cell power generator that generates direct current using the rich hydrogen. a device;
A boiler that generates steam using the combustion heat of fuel gas, and an air-conditioning system that separates the exhaust heat from the fuel cell power generator into exhaust heat steam, exhaust heat high temperature water, and exhaust heat low temperature water, and supplements the lack of exhaust heat with steam from the boiler. It has a water heater.

[Function] Therefore, by determining procedures for using waste heat steam, waste heat high temperature water, and waste heat low temperature water according to the purpose, and utilizing waste heat,
Exhaust heat can be used effectively.

[Example] An example of a fuel cell power generation, heating, cooling, and hot water supply system 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 10 to produce 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.

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 air conditioning and hot water supply. In other words, the exhaust heat steam is sent to the pipes 14S and 14 that are connected in sequence.
It is supplied to the absorption chiller 23 through SA and 14sB,
Piping 14SC110 sequentially connected to the piping 14SA
5D to the hot water heat exchanger 24 for heating, and further to the hot water storage tank 26 through the piping 143E connected to the piping 143C.The piping 14SA is supplied from the boiler 25 A pipe 25S for supplying steam is connected to the boiler 25, and steam from the boiler 25 is used when exhaust heat steam is insufficient. The fuel for this boiler 25 is the natural gas 10 that is branched from the pipe 10G and supplied through the final pipe 10GA.

The steam that has passed through the absorption refrigerator 23, hot water heat exchanger 24, and hot water storage tank 26 becomes water droplets, and is piped into pipes 23D and 24D, respectively.
, 26D, join the pipe 21D, and are collected in the hot well tank 21, then supplied to the boiler 25, and a portion of the fuel cell power generation system! ! It is designed to be reused as cooling water for 14 cars.

The exhaust heat high temperature water generated by the fuel cell power generation device 14 passes through the sequentially connected piping 14) 1.14HA, absorbs heat in the hot water heat exchanger 24, becomes low temperature, and is transferred to the piping 24L, 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. Further, a pipe 14HB is connected to the pipe 14H and guided to a hot water storage tank 26, and the waste heat high temperature water is absorbed in the hot water storage tank 26 and becomes low temperature water, which is transferred to the pipe 14H.
6L, 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 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.

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 heat exchanger 24 is circulated through the 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 pipe 26H via pipe 3B, and excess hot water returns to hot water tank 26 through pipe 26L.

Next, during normal operation, the direct current generated by the fuel cell power generator 14 flows through the wiring 14E via the contact 43.

The inverter 44 converts the power into alternating current, which is then supplied to the circulation pump 38. In addition, fuel cell power generation device 1
When the power load is small, the direct current generated at 4 flows through the wiring 14EA via the contact 45 and can be charged by the battery 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 14EH via the contact 48. 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 in a reforming furnace 72 to produce hydrogen, which is cooled by a fuel gas cooler 74, and then hydrogen gas is separated by a fuel gas steam separator 76 and supplied to the fuel electrode 70A. Fuel electrode 70
The hydrogen gas that did not react with oxygen in A is supplied to the reforming furnace 72 and used as fuel for the reforming furnace 72. The returned high-temperature water is heated by the fuel gas cooler 74 to about 80°C.

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 returning low temperature water also passes through the cathode outlet gas cooler 84 and is heated to approximately 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 separators 9 and 6 is heated through the heat exchanger 70C, and is turned into steam and used for the air conditioning/heating/water heating system.

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 5.

FIG. 3 shows a flowchart for controlling steam supplied to the absorption chiller 23. In step 300), exhaust heat steam is supplied from the fuel cell power generation device 14, and if this steam is sufficient, that is, for a certain period of time. If the temperature detected by a thermometer (not shown) provided in the absorption chiller 23 after use becomes less than a certain value T2 (step 302),
If there is a request for steam from the absorption chiller 23 that does not use steam from the boiler 25, the process returns to step 300 (step 304); if the temperature is above the constant value T2,
When natural gas lO is available (step 308)
, steam from the boiler 25 is also used (step 308).
When there is no longer a request for steam from the absorption chiller 23, 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 utilized for absorption refrigeration@23.

Next, Figure WS4 shows a flowchart for controlling heat absorption in the hot water heat exchanger 24, in which the exhaust heat high temperature water is flowed to the hot water heat exchanger 24 to heat the returning hot water (step 400), and the fuel cell power generation device 14 When the exhaust heat high temperature water from the hot water heat exchanger 24 is sufficient, that is, after a certain period of use, the temperature detected by a thermometer (not shown) installed in the hot water heat exchanger 24 reaches a constant value T3.
If the temperature is above (step 402), steam is not used. If the hot water outlet temperature of the hot water heat exchanger 24 is below a certain value, the process returns to step 400 (step 404). The temperature at step 402 is a constant value. If it is less than T3, check whether there is any waste heat steam left.Step 4
0B), if there is any leftover, then the exhaust heat steam is used (step 408); if this exhaust 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 T3 (step 410)
, 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. 5 shows a control flowchart for the hot water storage tank 26 and the hot water preheating exchanger 28. Initially, the make-up water in the hot water preheating exchanger 28 is supplied with waste heat low temperature water from the fuel cell power generation device 14. Preheat (step 5OO).

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. 6 (step 50B), and if this heating is insufficient (step 50B).
8) Check whether there is any waste heat steam remaining (step 51O); 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 512); with this heating. If there is enough (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 more, the steam from the boiler 25 is not used (
Step 514), if the exhaust heat steam is insufficient, when natural gas lO is available (step 516), steam from the boiler 25 is also utilized and heating is continued with this steam until the heating is sufficient. (Steps 518 and 520).

Therefore, the exhaust heat within the fuel cell power generation device 114 is effectively used in the hot water storage tank 26 and the hot water supply 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.

This second embodiment has a larger crotch than the first embodiment.

A cold water vertical heat storage tank 50 is installed in the cooling circulation path.
A hot water vertical heat storage tank 52 is provided in the heating circulation path.In addition, the heat contained in the return water for cooling and the return water for heating is recovered and transferred to the hot water preheating exchanger 28. An all-power reversible heat recovery air source heat pump 60 is equipped with a hot water heat exchanger 58 for supplying cold water or hot water, and 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.

[Effect of the invention] In the fuel cell power generation air conditioning/heating and hot water supply system according to the present invention, hydrogen/
The exhaust heat of the oxygen fuel cell power generation equipment is divided into exhaust heat steam, exhaust heat high temperature water, and exhaust heat low temperature water, and the insufficient amount of exhaust heat is supplemented with steam from the boiler. ,
Since the procedure for using waste heat high temperature water and waste heat low temperature water is established and waste heat is used, it has the excellent effect of increasing the utilization rate of waste heat and making it possible to use it effectively. .

[Brief explanation of drawings]

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. 1 is a control flowchart, and FIG. 1 is a block diagram showing the configuration of a second embodiment of the present invention. 10...Natural gas. 12・φ・Reformer, 14・・Fuel cell power generator, 23・・Absorption chiller, 24・・Hot water heat exchanger, 2511・・Boiler, 26・φ・Hot water storage tank, 28・・Hot water supply Preheat exchanger.

Claims (4)

[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, a boiler that generates steam using the combustion heat of the fuel gas, and a fuel cell power generation device. A fuel cell power generation air conditioning, heating, and hot water supply system comprising: an air conditioning, heating, and water supply system that divides the exhaust heat of the device into waste heat steam, waste heat high temperature water, and waste heat low temperature water, and supplements the amount that is insufficient in the exhaust heat with steam from a boiler. Device. (2) The fuel cell power generation air conditioning, heating and water supply system according to claim 1, wherein the heating and cooling water supply system is equipped with an absorption chiller that makes up for the lack of exhaust heat steam with steam from a boiler. (3) The air-conditioning, heating, and hot water supply system is provided with a heating heat exchanger that makes up for the lack of high-temperature waste heat water with waste heat steam, and makes up for the lack of these with steam from the boiler, or 2. The fuel cell power generation air conditioning, heating, and hot water supply device according to item 2. (4) The air-conditioning, heating, and water supply system includes a preheating exchanger that preheats with wastewater low temperature water, and heats the hot water preheated by this preheating exchanger with wastewater high temperature water, and uses waste heat steam to make up for the insufficient amount, and then heats the boiler. Claim 1 comprising a water heater that heats water in the order of steam.
3. The fuel cell power generation air conditioning, heating, and hot water supply system according to item 1, 2, or 3.