JP4007773B2 - Fuel cell exhaust heat recovery mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polymer electrolyte fuel cell, and more particularly, to an exhaust heat recovery mechanism that uses hot drainage of a polymer electrolyte fuel cell.
[0002]
[Prior art]
Fuel cells as non-polluting power generators can be classified according to the electrolyte used. Phosphoric acid fuel cells using phosphoric acid aqueous solution, molten carbonate fuel cells using carbonate, solids using zirconia ceramics An oxide fuel cell, a polymer electrolyte fuel cell using a cation exchange membrane, and the like are known.
These fuel cells generate electric power as a main output and exhaust heat corresponding to the output, and if the exhaust heat is recovered as hot water, the fuel cell operates as a cogeneration system combined with electric heat.
[0003]
The reaction temperature during power generation is about 200 ° C. for phosphoric acid fuel cells, 650 to 700 ° C. for molten carbonate fuel cells, 900 to 1000 ° C. for solid oxide fuel cells, and for polymer electrolyte fuel cells. Normal temperature to 90 ° C.
[0004]
Among the various types of fuel cells described above, the polymer electrolyte fuel cell can generate electricity at room temperature, and therefore can be easily started and stopped, can be reduced in size and weight because of its high output density, and the reaction operating temperature is low. Therefore, it is possible to use inexpensive materials and reduce costs, and it has features such as high power generation efficiency at low loads, and has a power generation function for households by collecting waste heat as hot water Think of it as a water heater.
Furthermore, the characteristic of the fuel cell that the amount of exhaust gas containing harmful components is small further enhances the suitability as a power generator for home use.
[0005]
However, when the polymer electrolyte fuel cell is used as a household power generation device, it is considered that the power generation output is about 1 KW, and in this case, the warm drainage flow rate is 0.4 liter / When the temperature is about 40 minutes, the temperature is about 0.7 liter / minute.
[0006]
This level of hot water (with a small flow rate) is insufficient to supply directly the amount of shower water normally consumed in the home (20 liters / minute) (insufficient hot water supply capacity). Therefore, when a polymer electrolyte fuel cell having an output of about 1 kW is used for home use, it is common to temporarily store hot waste water in a hot water storage tank and use the hot waste water (hot water) stored in the hot water storage tank. is there.
[0007]
In conventional hot water supply devices for bathrooms, baths, and kitchens, hot water storage tanks are installed outdoors, but there is a demand to save this space, equipment costs, and construction costs as much as possible. However, the conventional exhaust heat recovery mechanism of the polymer electrolyte fuel cell cannot meet such a request.
[0008]
[Problems to be solved by the invention]
The present invention has been proposed in view of the above-described problems of the prior art, and an object thereof is to provide a new exhaust heat recovery mechanism for a fuel cell that effectively uses the warm drainage of the fuel cell.
[0009]
[Means for Solving the Problems]
According to the present invention, in the exhaust heat recovery mechanism using the warm drainage of the polymer electrolyte fuel cell, the polymer electrolyte fuel cell 4 is connected to the warm drain pipe 6, and the warm drain pipe 6 is connected to the three-way valve 7. The opening degree adjusting means 22 of the three-way valve 7 is connected to the control device 14 by a control line 18, and a temperature sensor 10 for detecting the temperature of the hot water W in the bathtub 8 is A signal line 16 is connected to the control device 14, and further, a bypass pipe 21 that bypasses the polymer electrolyte fuel cell 4 is connected to the three-way valve 7, and the control device 14 has a temperature flowing from the hot drain pipe 6 to the bathtub 8. When the temperature of the drainage is lowered, it has a function of controlling the amount of water in the bypass pipe 21 by the temperature detection signal of the temperature sensor 10.
[0012]
Since the bathtub in the house is used as a warm drainage storage space, no special equipment for hot water storage is required and the cost is low.
[0014]
According to the present invention, in the exhaust heat recovery mechanism using the warm drainage of the polymer electrolyte fuel cell, the bathtub 91 is provided above the hot water storage tank 93 installed under the floor surface Fh via the support member 95. The solid polymer fuel cell 4 is connected with a warm drain pipe 6A, and the warm drain pipe 6A communicates with the hot water storage tank 93 via a three-way valve 100A and a pump 7A. A water supply pipe 20A from a water supply source 19 communicates with the fuel cell 4, and a bypass pipe 21A that bypasses the polymer electrolyte fuel cell 4 is connected to the water supply pipe 20A to the three-way valve 100A. Is provided with a water temperature sensor 10A, which is connected to the control device 14A via a signal line 16A, and the control device 14A reduces the temperature when the temperature of the hot water storage tank 93 is lowered. And it has a function of controlling the amount of water of the bypass pipe 21A by the detection signal of the capacitors 10A.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a first embodiment of the present invention, in which exhaust heat is stored in a warm drainage storage space installed in a house from warm drainage from a polymer electrolyte fuel cell (hereinafter abbreviated as PEFC). The block configuration of the collection mechanism 1 is shown.
[0020]
In FIG. 1, a pipe 6 of a warm drainage line through which warm drainage recovered from the PEFC 4 flows is connected to a hot water storage tank 8 that is a warm drainage storage space 9. The hot water tank 8 may be a bathtub installed in the house H.
[0021]
A three-way valve 7 is interposed in the pipe 6, and a control device 14 is connected to the opening degree adjusting means 22 through a control line 18.
[0022]
A temperature sensor 10 for detecting the temperature of the hot water W is attached to the hot water storage tank 8, and the temperature sensor 10 and the control device 14 are communicated with each other through a signal line 16.
In the figure, the three-way valve 7 is configured to be controlled by the control device 14. Manual operation may also be used.
[0023]
A water supply pipe 20 is connected to the PEFC 4 from an external water supply source, for example, a water supply 19.
[0024]
The operation of the exhaust heat recovery mechanism 1 of the fuel cell having the above configuration will be described.
In FIG. 1, when the PEFC 4 is activated to generate electric power, exhaust heat is generated. Therefore, the exhaust heat is recovered as hot water by the supply water flowing through the water supply pipe 20. The collected hot waste water passes through the pipe 6 by the feed water pressure and is sent to the bathtub 8.
[0025]
Here, when the temperature of the hot waste water is 60 ° C., for example, when hot water is stored at the temperature of 60 ° C. as it is, the hot water is directly fed to the bathtub 8 through the pipe 6.
However, when the hot waste water at 60 ° C. is cooled to a predetermined use temperature and stored in hot water, the following is performed.
[0026]
When lowering the warm drainage to a predetermined operating temperature, for example, when lowering the warm drainage at 60 ° C. to a suitable bathing temperature of 42 ° C., the amount of water passing through the pipe 21 bypassing the PEFC 4 from the water supply 19 through the pipe 20 7 and the hot water temperature is lowered by the opening degree adjusting means 22. And it supplies to the bathtub 8.
[0027]
In order to ensure a predetermined appropriate bathing temperature, for example, 42 ° C., the control device 14 controls the operation of the three-way valve 7 by the temperature detection signal of the temperature sensor 10 to control the amount of hot water supplied to the bathtub 8. Manual operation may also be performed.
[0028]
FIG.2 and FIG.3 shows 2nd Embodiment of waste_water | drain storage space, The bathtub was formed with the double wall and the form which used the hollow part between the double walls as the warm waste water storage space is shown.
[0029]
2 and 3, the bathtub 80 installed in the house H is integrally formed with a double structure of an inner wall 81 and an outer wall 82, and a hollow portion 83 is formed between the inner wall 81 and the outer wall 82. .
[0030]
A plurality of support members 84 that connect the inner wall 81 and the outer wall 82 are provided in the hollow portion 83. In FIG. 3, the support member 84 is only at the bottom, but may be provided on the side wall as necessary for maintaining the shape of the bathtub and maintaining the strength.
[0031]
Two pipes 86 and 87 are provided on the side surface of the outer wall 82 so as to pass through the outer wall 82 and communicate with the hollow portion 83 and the outside. The pipe 87 is communicated with the PEFC 4 (see FIG. 1) via the hot drainage line 6. The pipe 86 communicates with the PEFC 4 via a bathtub, a hot water supply facility, etc., where hot water is used, or a circulation pipe (not shown).
[0032]
In addition, the hot water storage capacity in the case where the bathtub has a double structure is sufficient capacity as a normal hot water storage tank, with the hollow portion 83 being 544 liters when the dimensions of the bathtub are 1600 × 800 × 700 and external shape: 1800 × 1000 × 800. . Therefore, it is not necessary to separately install a warm drainage storage space.
[0033]
FIG. 4 shows a block configuration of the exhaust heat recovery mechanism 2 according to the third embodiment, for example, where a hot water storage tank is provided under the floor of a bathroom of a unit bath to form a warm drainage storage space.
In FIG. 4, a hot water storage tank 93 is installed under the floor of the bathroom 90 in the house H, and in the figure under the floor surface Fh below the bathtub 91 and the washing place 92 via a plurality of support members 95.
[0034]
On the other hand, a pipe 6A of a warm drainage line through which warm drainage recovered from the PEFC 4 flows is connected to a hot water storage tank 93 which is a warm drainage storage space 9. A pump 7A is interposed in the pipe 6A. In the third embodiment of FIG. 4, the pump 7A may be manually operated. However, as will be described later with reference to FIG. 5, the pump 7 </ b> A may be operated by the control device in response to the hot water temperature in the bathtub 8.
[0035]
A water supply pipe 20A communicates with PEFC 4 from an external water supply source, for example, water supply 19.
[0036]
The operation of the exhaust heat recovery mechanism 2 configured as described above will be described.
In FIG. 4, when the PEFC 4 is operated to generate power, exhaust heat is generated, so that the exhaust heat is recovered as hot water by the feed water flowing through the feed water pipe 20A. The collected hot waste water is sent to the hot water storage tank 93 by the pipe 6A and the pump 7A. Since the hot water temperature in the hot water storage tank 93 is normally stored at 60 ° C., if the temperature required for the hot water supply facility is too high, the hot water tank 93 is mixed with clean water and cooled to an appropriate temperature.
[0038]
The exhaust heat recovery mechanism shown in FIG. 5 is a modification of the third embodiment shown in FIG.
In this modification, the three-way valve (indicated by reference numeral 100A in FIG. 5) is controlled by a control device (indicated by reference numeral 14A in FIG. 5), as shown in FIG.
[0039]
That is, in FIG. 5, a three-way valve 100A is interposed in the pipe 6A, and the opening degree adjusting means 22A is connected to the control device 14A via the control line 18A.
The hot water storage tank 93 is equipped with a temperature sensor 10A that detects the temperature of the hot water W, and the temperature sensor 10A is connected to the control device 14A via a signal line 16A.
[0040]
In the exhaust heat recovery mechanism shown in FIG. 5, the three-way valve 100A is controlled by the control device 14A, and as a result, the flow rate of the hot waste water flowing through the pipe 21A and the pipe 6A is adjusted, and the hot water W becomes a desired temperature. Has been. In other words, by setting the hot water W as a temperature necessary for hot water supply, hot water can be stored at that temperature, so that hot water can be supplied as it is.
The pump 7A may be omitted if the pressure of the water supply 19 is sufficient.
[0074]
【The invention's effect】
The effects of the present invention are listed below.
(1) Hot water from the polymer electrolyte fuel cell is stored in a domestic hot water storage tank, making it easy to use hot water.
(2) If the hot drainage storage space is made into a bathtub, it is not necessary to install special equipment for hot water storage.
(3) If a bathtub is made into a double structure and hot water is stored in a hollow part, it can be made into a hot water storage tank without taking a special space. In addition, the airtightness is good, there is no fear of water leakage, and the heat insulation is good.
(4) If a hot water storage tank is installed under the floor of a house, a special space is not required and piping work is facilitated.
[Brief description of the drawings]
FIG. 1 is a block diagram of a first embodiment of the present invention.
FIG. 2 is a perspective view showing a main part of a second embodiment of the present invention.
3 is a cross-sectional view of FIG.
FIG. 4 is a block diagram of a third embodiment of the present invention.
FIG. 5 is a block diagram showing a modification in which a control system is added to the embodiment of FIG.

Claims (2)

  In the exhaust heat recovery mechanism using warm drainage of a polymer electrolyte fuel cell, a warm drain pipe (6) is connected to the polymer electrolyte fuel cell (4), and the warm drain pipe (6) is a three-way valve ( 7) is communicated with the bathtub (8), the opening adjusting means (22) of the three-way valve (7) is connected to the control device (14) by a control line (18), and the bathtub ( 8) The temperature sensor (10) for detecting the temperature of the hot water (W) is connected to the control device (14) through a signal line (16), and further bypasses the polymer electrolyte fuel cell (4) ( 21) is connected to the three-way valve (7), and the control device (14) detects the temperature of the temperature sensor (10) when the temperature of the warm drainage flowing from the hot drain pipe (6) to the bathtub (8) is lowered. It has a function of controlling the amount of water in the bypass pipe (21) by a signal. Exhaust heat recovery mechanism that.   In the exhaust heat recovery mechanism using hot waste water of a polymer electrolyte fuel cell, a bathtub (91) is provided above a hot water storage tank (93) installed under the floor (Fh) via a support material (95). The solid polymer fuel cell (4) is connected to a hot drain pipe (6A), and the hot drain pipe (6A) is connected to the hot water storage tank (93 via a three-way valve (100A) and a pump (7A). ), A water supply pipe (20A) from a water supply source (19) is connected to the polymer electrolyte fuel cell (4), and the polymer electrolyte fuel cell is connected to the water supply pipe (20A). A bypass pipe (21A) for bypassing (4) is connected to the three-way valve (100A), a water temperature sensor (10A) is provided in the hot water storage tank (93), and the water temperature sensor (10A) is connected to a signal line (16A). ) To the control device (14A) via When the temperature of the hot water storage tank (93) is lowered, the control device (14A) has a function of controlling the amount of water in the bypass pipe (21A) by the detection signal of the temperature sensor (10A). Collection mechanism.

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