JPS62145659A - Cooler for fuel cell - Google Patents

Abstract

PURPOSE:To enhance reliability, by providing the inlet port of each cooling pipe with an intermediate pipe of larger fluid passage cross section than the cooling pipe to prevent the flow of cooling water in the cooling pipe from becoming unstable. CONSTITUTION:A main feed pipe 11 is provided with a main flow rate control valve 21 and connected to a main outflow pipe 17 through a pump and a steam separator so that a cooler is constituted. Each of a plurality of cooling pipes 7 provided in parallel with each other is connected to an intermediate pipe 8 of larger fluid passage cross section than the cooling pipe, at the inlet port of the cooling pipe between an inlet manifold 9 and a cooling plate 5. In the intermediate pipe 8, the cooling pipe 7 extending from the cooling plate 5 and another cooling pipe 7 extending from the inlet manifold 9 are laid on each other in the longitudinal direction of the intermediate pipe and opened at the ends of the cooling pipes near the opposite ends of the intermediate pipe so that a small fluid passage cross section, a large fluid passage cross section and another small fluid passage cross section communicate with each other in the direction of an arrow in the drawing, at the inlet port of the cooling pipe extending from the cooling plate.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a fuel cell cooling device.

[Technical background of the invention and its problems]

In recent years, fuel cells have been considered as a power generation device from the viewpoint of effective energy use, and their development has become active.

In general, a fuel cell supplies stacked electrode plates with, for example, oxygen as an oxidant and hydrogen as a fuel, and converts the energy generated by the reaction of the fuel into electrical energy.

By the way, in a fuel cell, heat is generated due to the above reaction, but
In order to increase the power generation efficiency of a fuel cell, it is necessary to remove heat generated from the electrode plates and cool them, as well as to maintain the entire body at a uniform temperature.

As a fuel cell cooling device for this purpose, for example,
There are those described in JP-A-33670 and JP-A-52-13638. This is approximately the same as that shown in FIG. 8, for example, and will be explained using FIG. 8 as an example. That is, a large number of electrode plates 10 stacked in the vertical direction
A plurality of cooling plates 105 are interposed at appropriate intervals in the electrode plate group 103 consisting of 1. This electrode plate group 103 is provided in a plurality of stages, but only one stage is shown in FIG. 8, and the other stages are omitted. Cooling plate 1 of electrode plate group 103
A plurality of cooling pipes 107 are connected in parallel to the cooling pipe 05, and an inlet eyebrow hold 109 is connected to the inlet side of each cooling pipe 107. Inlet side manihole l” 1
A main supply pipe 111 is connected to 09, and both constitute an inlet pipe 113. In addition, each cooling pipe 1
The outlet side of 07 is connected to an outlet manifold 115.

A main outlet pipe 117 is connected to this outlet manifold 115, and both constitute an outlet pipe 119. The main supply pipe 111 has a main flow control valve 1.
21 is provided, and the main supply pipe 111 and the main outlet pipe 117 are connected via a pump and a stem gas separator (not shown). Therefore, the cooling water as a cooling fluid supplied by the pump drive is adjusted in flow rate by the main flow control valve 121 and is supplied from the main supply pipe 111 to the cooling pipe 107 of the cooling plate 105 via the inlet eyebrow hold 109.

In the cooling pipe 107 in the cooling plate 105, the cooling water flows through the electrode plate 1.
While absorbing the heat generation of 01 and cooling it, it is boiled and becomes a two-phase flow of a stem vapor phase and a liquid phase and flows out from the outlet side of the cooling pipe 107 via the outlet manifold 115 to the main outlet pipe 117. However, in the above-mentioned λ fuel cell cooling device, cooling, 5 (boiling evaporation of cooling water as 5 bodies occurs in the horizontally provided cooling pipe 107,
Moreover, a plurality of cooling pipes 107 are connected to the inlet eyebrow hold.
Since it is connected in parallel to O9, the cooling pipe 107
The flow of cooling water inside the tank was likely to become unstable (/A, dynamic instability phenomenon). When this flow υJ instability phenomenon occurs, the temperature of the electrode plate becomes non-uniform, and the reliability of the device is also significantly reduced.

Such an unstable flow phenomenon has been known in the past in boilers having a configuration similar to that of the fuel cell described above. Measures to prevent flow instability in this boiler include:
Generally, there is a device that has a fixed restrictor (Lamont/Zull) on the inlet side of the fluid that provides a large flow resistance, so that the pressure loss of the fixed restrictor becomes dominant against the pressure loss of two-phase flow. .

By the way, in a fuel cell, there is a demand for making the cooling plate 105 as thin as possible, and as a result, the length of the cooling pipe 107 that penetrates the cooling plate 105 is limited to several mm. For this reason, if a fixed throttle (nozzle to Ramon 1) conventionally used in boilers is inserted in the cooling pipe 107,
There was a problem in that the fixed throttle part became too thin and could become clogged, resulting in a lack of reliability.

[Purpose of the invention]

This invention was devised in view of the above-mentioned problems, and is capable of preventing the phenomenon of unstable flow of cooling water in cooling pipes provided on a cooling plate, and providing a highly reliable fuel cell cooling device. The purpose is to provide.

J Summary of the Invention] In order to achieve the above object, the present invention provides a cold JJI device which has a plurality of cooling pipes interposed between a plurality of vertically stacked electrode plates and through which a cooling fluid can flow. , a fuel cell cooling system comprising: an inlet pipe to which the inlet side of each of the cooling pipes is connected and capable of supplying cooling fluid to each cooling pipe; and an outlet pipe to which the outlet side of the cooling pipe is connected to which the cooling fluid flows out from each cooling pipe. In the apparatus, an intermediate pipe having a larger flow path surface area than the cooling pipe is interposed on the inlet side of each of the cooling pipes.

〔Effect of the invention〕

According to the configuration of this invention, the cooling water supplied from the inlet pipe to the cooling pipe not only receives friction loss in the cooling pipe and the intermediate pipe, but also undergoes rapid expansion of the flow path in the intermediate pipe and sudden contraction in the cooling pipe. Since a larger loss can be obtained, this pressure loss becomes dominant over the pressure loss of the two-phase flow. For this reason, if
Even if some disturbance occurs on the inlet side of the cooling pipe, the flow of cooling water is maintained in a stable state, so that it does not affect other cooling pipes installed in parallel. Therefore, the flow rates of the cooling pipes provided in parallel can be made approximately equal, and the electrode plates can be cooled to approximately equal temperatures.

Since the cross-sectional area of the cooling pipe through which the cooling water flows is not reduced, there is no risk of clogging, etc., and reliability is improved.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 shows a perspective view of the battery cooling device, which is basically substantially the same as that in FIG. 8 above. That is, in the electrode plate group 3 consisting of a large number of electrode plates 1 layered in the vertical direction,
A plurality of cooling plates 5 are interposed at appropriate intervals. Although this electrode plate group 3 is provided in a plurality of stages, only one stage is shown in FIG. 1, and the other stages are omitted. A plurality of cooling pipes 7 are connected through each cooling plate 5 of the electrode plate group 3 in parallel, and an inlet manifold 9 is connected to the inlet side of each cooling pipe 7. A main supply pipe 11 is connected to this inlet manifold 9, and both constitute an inlet pipe 13. Furthermore, an outlet manifold 15 is connected to the outlet side of each cooling pipe 7. This outlet manifold 15 is connected to a main outlet pipe 17, and both constitute an outlet pipe 19.

The main supply pipe 11 is provided with a main flow rate regulating valve 21, and the main supply pipe 11 and the main flow outlet pipe 17 are connected via a pump and a steam separator (not shown), and the cold 7.11 device is controlled by G, %. has been completed.

Each cooling pipe 7 is connected between the manifold 1 and the cooling plate 5 on the inlet L1 side of the cooling plate 5 of the iJ number of cold pipes 7 provided in parallel. An intermediate tube 8 having a larger flow path area than the cooling section 27 is interposed. Inside the intermediate tube 8, cooling tubes 7 extending from the artificial manifold 9 side and the cooling plate 5 side are provided overlapping each other in the longitudinal direction of the intermediate tube 8, and their ends are connected to the intermediate tube 8. The openings are at alternate positions inside.

The inlet side of the cooling pipe 7 is directed in the direction indicated by the arrow in FIG.
They are communicated so that the flow path area becomes small, large, and small.

Next, the operation of one embodiment of the present invention configured as described above will be described.

The total flow rate of the cooling water as a cooling fluid supplied from the outside in a liquid phase is adjusted by the main flow rate adjustment valve 21 according to the operating conditions of the fuel cell, and the total flow rate is adjusted by the main flow rate adjustment valve 21 according to the operating conditions of the fuel cell. 9 and flows into each cooling pipe 7.

Then, as shown by the arrow in FIG. It flows out to the position P of the intermediate pipe 8, the flow path suddenly expands, it makes a U turn from P to the direction Q of the intermediate pipe 8, it suddenly contracts again at the position Q, it flows into the cooling pipe 7, and the cooling plate 5 Flow into the side. The cooling water that has flowed into the cooling plate 5 side absorbs the heat generated by the electrode plate 1 as it passes through the cooling pipe 7 and is cooled, while at the same time boiling and becoming a two-phase fluid of a vapor phase and a liquid phase and flowing to the outlet side. and flows from the outlet manifold 1.5 to the main outlet pipe 17.

When the cooling water flows through the inlet side of the cooling pipe 7, there is a flow resistance caused by the sudden contraction of the flow path when it flows into the cooling pipe 7 from the artificial manifold 9, a flow resistance within the cooling pipe 7, and a flow resistance caused by the intermediate pipe 8.
Flow resistance due to U-turn from P to Q,
Flow resistance occurs due to rapid expansion and contraction of the flow path at positions P and Q, and flow resistance within the cooling pipe 7 is experienced again. For this reason, the cooling water causes a significantly large pressure loss on the inlet side of the cooling pipe 7, so that the pressure of the two-phase flow within the cooling plate 5 is lost. Cooling pipe 7
The flow of cooling water on the inlet side is maintained in a stable state without being affected. Therefore, the cooling water on the inlet side of each cooling pipe 7 installed in parallel is not affected by disturbance and is maintained in a stable state, so that cooling water with approximately the same flow rate is in each cooling pipe 7. As a result, the electrode plate 1 can be cooled approximately evenly.

Here, the flow resistance ΔP of this embodiment and the conventional example will be compared based on specific numerical values. Cooling pipe 7 has 1 line 2 ■l
, an outer diameter of 4 fins, an inner diameter of 101 for the intermediate tube 8, the length Ll of the overlapping portion of the cooling pipe 7 in the order of 40 mm, and the length LO of the inlet manifold 9 and the cooling plate 5 as 50 mm. shall be. Further, as an example of the inlet of the conventional cooling pipe 107, one having the same diameter as the cooling pipe 7 of this embodiment is used, and the inlet eyebrow hold 10
The distance LO between 9 and the cooling plate 105 is 50, which is the same as in this embodiment.
be concerned. 18 on the inlet side of both cooling pipes 7.107.
Cooling water at 0'C flows at a flow rate of 1 m/s.
Ozu Thick 2' Wrapped A5 + I A1. Ten fortune of Judama appetizer 2? ! P? ■ Length LO between inlet manifold 9 and cooling plate 5 (5
0am) Flow resistance ΔPO ΔPO=339 (Pa) ■Flow resistance ΔP1 at the overlapping portion of the cooling pipe 70 Ll (40 mm) ΔP1=271 (Pa) ■Length Ll of the intermediate pipe 8 (40 mm) Flow resistance ΔP2 ΔP2=0.8 (Pa) ■Flow resistance ΔΔP3 due to sudden expansion of the flow path at position I)
=392 (Pa) ■Flow U1 resistance due to U turn at position P ΔP4 ΔP4
=12 (Pa) ■Flow resistance ΔP5 due to U-turn at position Q ΔP5
=12 (Pa) ■Flow resistance ΔΔP6 due to sudden contraction of flow path at position Q
186 (Pa) The total of this example is 1212.8 (Pa).

On the other hand, in the conventional example, the flow resistance is only in the part (2) above.

Therefore, the flow resistance of this embodiment is about 3°6 times higher than that of the conventional example, and it can be seen from this that the pressure tn loss of this embodiment is significantly larger than that of the conventional example.

Further, in this device, since the cross section of the cooling pipe 7 is not reduced, there is no fear of clogging or other problems, and reliability is improved.

4 to 7 show other embodiments of the present invention. It should be noted that components corresponding to the first embodiment are indicated by the same reference numerals, and a detailed explanation will be omitted.

In the second embodiment shown in FIGS. 4 and 5, two orifices i18 are provided perpendicularly to the longitudinal direction in the intermediate pipe 8, and an orifice hole 18a is provided at the center of the orifice slope 18. is formed to have the same inner diameter as the cooling pipe 7. In this case, the cooling water flow path repeats rapid expansion and contraction from small to large to small to large to small to large to small, which increases the flow resistance and causes a large pressure loss. The flow stability of the cooling water in the cooling pipe 7 is improved.

Note that 20 is a spacer for providing the orifice slope 18. Regarding this second embodiment, the flow tn loss ΔP when the distance LO (50 sm) between the inlet manifold 9 and the cooling plate 5 is the same as that of the conventional example will be compared with specific numerical values. The length of the cooling pipe 7 is L1 + L 2 = 20 am
The inner diameter, outer diameter, and test conditions of the pond intermediate pipe 8 are as follows.
It is the same as that of the example.

, 1) '11 Length of pipe 7 1 ← L2 = 20 Flow resistance Δ Pl ΔP1 = 136 (Pa) @Flow resistance ΔΔP2 due to sudden expansion of flow path in intermediate pipe 8
409 (Pa) 0 Flow resistance Δ due to sudden contraction of the flow path at orifice 18a
P3 ΔP3=1379 (Pa) On the other hand, the conventional example has 339 (Pa) as mentioned above.
). Therefore, it can be seen that the flow resistance of the second embodiment is about 6.2 times that of the conventional example, and the pressure loss is extremely large.

In the third embodiment shown in FIGS. 6 and 7, two partition walls 30 are provided perpendicularly to the longitudinal direction inside the intermediate pipe 8, and are supported by the partition walls 30, have the same inner diameter as the cooling pipe 7, and are open at both ends. Intermediate inner tube 2
8. The intermediate inner tubes 28 are arranged in a staggered manner with one end overlapping each other in the longitudinal direction. In this third embodiment, in addition to the fact that the flow path on the inlet side of the cooling pipe 7 is lengthened by the overlap of the intermediate inner pipe 28, the flow path of the cooling water is As large and small, rapid expansion and sudden contraction are repeated alternately, the flow resistance of the cooling water increases, and at the overlapping part of the intermediate inner pipe 28, the cooling water makes a U-turn and the flow path is reversed, causing flow resistance. This increases the pressure loss, which improves the flow stability of the cooling water.

[Brief explanation of drawings]

M I Ir71 'II, y MA Ria2+suΔ110t-FLP+ =? L kbk - 1 bone in total) The first embodiment of the city/l eight unit is shown, Figure 1 is an overall perspective view, Figure 2 is a partial sectional view of Figure 1 showing the inlet side of the cooling pipe,
FIG. 3 is a sectional view taken along line m-rn in FIG. 2, FIGS. 4 and 5 show the second embodiment, FIG. 4 is a sectional view corresponding to FIG. 2, and FIG. 6 and 7 show the third embodiment, FIG. 6 is a sectional view corresponding to FIG. 2, FIG. 7 is a river surface view corresponding to FIG. 3, and FIG. The figure is an overall sectional view of a conventional example. 1. Electrode plate 5. Cooling plate 7. Cooling pipe 8. Intermediate pipe 13. Inlet piping 19. Outlet piping Figure 3 Figure 4 Figure 5 Valve -e-field Figure 6 Figure 7

Claims (1)

[Claims] a cooling plate that is interposed between a plurality of vertically stacked electrode plates and has a plurality of cooling pipes through which a cooling fluid can flow;
A fuel cell cooling device comprising: an inlet pipe to which the inlet side of each cooling pipe is connected and capable of supplying cooling fluid to each cooling pipe; and an outlet pipe to which an outlet side of the cooling pipe is connected and allows cooling fluid to flow out from each cooling pipe. A fuel cell cooling device characterized in that an intermediate pipe having a larger flow area than the cooling pipe is interposed on the inlet side of each of the cooling pipes.