JP4066429B2 - Cogeneration system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cogeneration system using exhaust heat of an internal combustion engine such as a fuel cell or a gas engine, and more particularly to a cogeneration system using a backup burner.
[0002]
[Prior art]
A cogeneration system that uses the exhaust heat of a fuel cell and uses a backup burner is known. To better understand the present invention, a case where the present invention is applied to a fuel cell will be described with reference to FIG. 2 as an example.
In FIG. 2, the fuel cell 1 that implements the cogeneration system of the present invention includes a heat exchanger 2 by exhaust heat, and the heat exchanger 2 supplies hot water heated through a line L1 to a separate tank 3, Moreover, the water from the tank 3 is sent to the heat exchanger 2 through the line L2. In the figure, 2a is a pump provided in the line of the heat exchanger 2.
[0003]
This tank 3 is provided in a hot water supply apparatus generally indicated by reference numeral 4, and water supplied from a water supply source 5 is supplied to the tank 3 via a line L3. At the same time, the line L3 is mixed with the mixing means 6 (A mixer, usually a mixing valve), and a line L 3 from the tank 3 is also connected to the mixing means 6. The hot water mixed by the mixing means 6 is sent from the backup burner 7 to the hot water supply section 8 via the line L5. A valve V is provided in the line L5.
[0004]
When hot water is accumulated in the tank 3 at the time of use, hot water is mixed with hot water and the backup burner 7 is not used at that time. However, when the upper temperature of the tank 3 is low, hot water is made with the backup burner 7. It has become.
Even if this cogeneration system is not the case of the fuel cell 1, it can be applied to, for example, a gas engine, a diesel engine, or the like.
[0005]
Thus, in the hot water supply apparatus, the fuel cell 1, the tank 3, the mixing means 6, and the backup burner 7 are required as main components. If these components are separately provided, space is required. As shown in FIG. 2, a hot water supply device 4 including a tank 3, a mixing unit 6, and a backup burner 7 is used as a unit, which is connected to the fuel cell 1.
[0006]
However, when it is desired to reduce the capacity of the tank 3 with the recent improvement in efficiency, or to increase the capacity of the tank 3 as the required amount of hot water increases, the apparatus shown in FIG. It is difficult to change only the tank 3.
Therefore, as shown in FIG. 3, a technique has been proposed in which the fuel cell 1, the mixing means 6 and the backup burner 7 are integrated into a unit 40 and only the tank 3 is separately provided. In FIG. 3, parts corresponding to those in FIG.
[0007]
However, in the technique shown in FIG. 3, when the tank 3 is replaced, four lines of the circulation lines L 1 and L 2 between the fuel cell 1 and the tank 3, the water supply line L 3 to the tank 3, and the hot water supply line L 4 from the tank 3, Since the pipes are reconnected, the work is troublesome.
[0008]
The present applicant has proposed a fuel cell exhaust heat recovery mechanism capable of performing hot water supply work suitable for a domestic bath in Patent Document 1.
[0009]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-372303
[Problems to be solved by the invention]
Accordingly, a main object of the present invention is to provide a cogeneration system that can suppress an increase in the number of connection lines and efficiently use exhaust heat when a tank is separately provided.
[0011]
[Means for Solving the Problems]
According to the present invention, in the cogeneration system using the exhaust heat of the fuel cell 1 or the gas engine, the exhaust heat source (for example, the fuel cell 1) and the hot water tank circulating water (lines L1, L2, tank 3 are circulated). Water) and / or water supply (water supplied from the water supply source 5: water, for example, clean water), hot water in the hot water tank 3, and / or mixing means of hot water heated by the exhaust heat source 1 and water supply 6 and the backup burner 7 as one unit 4A, the hot water tank (tank 3) is placed separately, the line L2 from the water supply source 5 is connected to the hot water tank 3, and the line L1 from the hot water tank 3 is mixed. The first branch line L6 branched from the line L2 from the water supply source 5 is connected to the line L1 from the hot water storage tank 3 through the heat exchanger 2 and connected to the means 6. Line L2 A second branch line L7 branched from the water supply source 5 is connected to the mixing means 6, and a one-way valve 10 that allows water from the water supply source 5 to flow but not from the mixing means 6 is provided in the second branch line L7. The mixing means 6 is connected to the hot water supply unit 8 via a backup burner 7.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
[0013]
In FIG. 1, the hot water supply unit 4 </ b> A is composed of a fuel cell 1 and a mixing means, for example, a mixing valve 6 and a backup burner 7. The hot water storage tank 3 is a separate type with respect to the hot water supply unit 4A. The fuel cell 1 includes a heat exchanger 2 with a pump 2a that uses exhaust heat of the fuel cell.
[0014]
A water supply line L2 is connected to the hot water storage tank 3 from the water supply source 5 to supply clean water. A first branch line L6 from the first branch point B1 of the water supply line L2 and a second branch line L7 branch from the second branch point B2, and the first branch line L6 is the fuel cell. The second branch line L 7 is connected to the mixing valve 6 in the heat exchanger 2 housed in 1.
[0015]
On the other hand, from the tank 3, a hot water supply line L1 is connected to a hot water supply section 8 via a mixing valve 6, a backup burner 7, and an on-off valve V.
[0016]
A junction point G is formed in a region between the tank 3 and the mixing valve 6 in the hot water supply line L1, and the heat exchanger 2 and the junction point G are connected by a line L8.
The branch line 7 is provided with a one-way valve (check valve) 10 that allows water from the water supply source 5 to flow but not from the mixing valve 6.
[0017]
According to the first embodiment having the above-described configuration, the fuel cell 1 and the backup burner 7 are integrated, so that the city gas pipe can be easily attached and the tank 3 can be provided with two pipes.
[0018]
It should be noted that the illustrated embodiment is merely an example, and is not a description to limit the technical scope of the present invention.
[0019]
【The invention's effect】
Since the present invention is integrated with the fuel cell and the backup burner, it is easy to install the city gas pipe, and the number of pipes to the tank is two, and the pipe work when replacing the tank is easy.
[Brief description of the drawings]
FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention.
FIG. 2 is a block diagram showing an example of a conventional cogeneration system.
FIG. 3 is a block diagram showing an example of a prior art different from FIG. 2;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Fuel cell 2 ... Heat exchanger 3 ... Tank / hot water storage tank 5 ... Water supply source 6 ... Mixing valve 7 ... Backup burner 8 ... Hot water supply part 10 ... Reverse Stop valve / one-way valve B1-B2 ... Branch point G ... Joint point L1-L8 line

Claims (1)

  In a cogeneration system using the exhaust heat of a fuel cell or a gas engine, a heat exchanger between the exhaust heat source and the hot water tank circulating water and / or feed water, and the hot water and / or hot water heated by the hot water and / or waste heat source of the hot water tank The mixing means and the backup burner as one unit, the hot water tank is set separately, the line from the water source is connected to the hot water tank, the line from the hot water tank is connected to the mixing means, and the water source Connecting the first branch line branched from the line from the line from the hot water storage tank via the heat exchanger, and connecting the second branch line branched from the line from the water supply source to the mixing means, The second branch line is provided with a one-way valve that allows water from the water supply source to flow but not from the mixing means, and the mixing means is connected to the hot water supply unit via a backup burner. Cogeneration system according to claim Rukoto.

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