JPS61220009A - Pressure controller for metal hydride tank - Google Patents

Abstract

PURPOSE:To keep tank inner pressure approximately constant irrespective of the fluctuation of a load by controlling a heating value used for heating metal hydride according as the inner pressure of the fuel tank changes hourly. CONSTITUTION:A feed heating value control means 13 composed of flow control valves 14 and 16 is installed on a feed pipe 12 for feeding heat to the tank 10 from an engine 11 as a hydrogen gas burning device. Then, when the heat arising in the engine 11 is sent to the tank 10 to heat the metal hydride, the feed heating value is controlled by adjusting the apertures the valves 14 and 16 by means of an arithmetic controller 18. Accordingly as the hydrogen gas pressure in the tank changes hourly, the apertures of the valves 14 and 16 are controlled. Thus the hydrogen gas pressure in the tank 10 is caused to follow the load fluctuation quickly. Accordingly the tank inner pressure can be kept approximately constant.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is a method for controlling the pressure of a metal hydride tank in a hydrogen gas combustion system such as an engine system using metal hydride, which is one of the storage forms of hydrogen. This relates to a pressure control device that maintains a constant pressure regardless of load fluctuations.

[Prior Art] In general, an engine system using a metal hydride is, as shown in FIG. 2, mainly composed of a tank 1 and an engine 2 that use the metal hydride as a fuel source.

When filling the metal hydride tank 1 with hydrogen gas, the hydrogen gas is occluded in the hydrogen absorbing alloy by pressurizing and cooling. On the other hand, when releasing the hydrogen gas, it is necessary to heat it. The tank 1 not only stores fuel hydrogen gas, but also functions as a heat exchanger and a pressure vessel.

In such a metal hydride engine system, hydrogen stored in gaseous form in the space between the hydrogen storage alloy and the heat exchange heat transfer surface in the tank l is introduced to the engine to start the engine and obtain power. At the same time, exhaust gas from the engine or heated engine cooling water is introduced into the fuel tank 1 to heat the fuel tank. As a result, hydrogen gas is released from the metal hydride, and the gas is guided back into the engine to continue operating the engine.

In this system, when the engine requires output, the amount of hydrogen gas used increases, so it is necessary to release hydrogen gas from the metal hydride in proportion to the amount used. However, when this system is used in an engine of an automobile or the like, the pressure within the tank 1 will change greatly due to changes in the amount of hydrogen used because the engine load fluctuations are large.

In general, fuel tank pressure control using metal hydride is
A set pressure level or pressure range in the fuel tank is determined, and when the pressure falls below this pressure, all waste heat is supplied to the fuel tank, and when the tank internal pressure is higher than the set pressure, valve 3. 4 is opened and closed to discharge waste heat through a bypass path 5 without passing it through the tank.

Even if such a system is adopted, especially in a metal hydride engine system where the load fluctuates rapidly, it will not be able to keep up with the fluctuations, and in some cases the pressure will become excessive, or when necessary, the supply amount will be reduced due to a drop in the metal hydride tank pressure. In the event of an emergency stop when the amount of hydrogen used is zero, the pressure inside the fuel tank will become excessive, affecting the safety of the tank.

[Problems to be Solved by the Invention] In the hydrogen gas combustion system using the metal hydride described above, the present invention does not simply control the heating of the metal hydride in the tank based only on the pressure level in the fuel tank. , the amount of heat for heating the metal hydride is controlled according to the time change in the pressure inside the fuel tank, that is, the degree of the pressure gradient, so that the pressure inside the tank is kept almost constant regardless of the load. This is the purpose.

[Means to solve the problem 1 In order to achieve the above object, in the present invention.

It is equipped with a tank containing a metal hydride and a hydrogen gas combustion device that uses the hydrogen gas occluded in the metal hydride as a fuel source, and the heat generated in the hydrogen gas combustion device is sent to the tank to burn the metal. In a hydrogen gas combustion system for heating hydride, a supply route for supplying heat from the hydrogen gas combustion device to a tank is provided with a supply heat amount control means, and a pressure of hydrogen gas in the tank is detected. A pressure sensor is provided, and an arithmetic control device is connected to the pressure sensor, which determines temporal changes in the pressure detected by the pressure sensor and controls the above-mentioned heat supply amount control means in accordance with the temporal changes. ing.

[Function] In the control device of the present invention having the above configuration, when the heat generated in the hydrogen gas combustion device is sent to the tank to heat the metal hydride, the amount of heat sent from the combustion device to the tank is , is controlled according to temporal changes in the hydrogen gas pressure in the tank by a feeding heat amount control means provided in the feeding path, so that the hydrogen gas pressure in the metal hydride tank can respond well to load fluctuations. due to load fluctuations.
-The tank internal pressure can be kept almost constant regardless of the
It's true.

[Example] FIG. 1 shows the configuration of a metal hydride engine system using the pressure control device of the present invention.

This system includes a tank 10 containing a metal hydride and an engine 11 as a hydrogen gas combustion device. The tank 10 is operated by fuel hydrogen gas supplied by the tank 10, and the heat generated thereby is sent to the tank 10 to heat the metal hydride in the tank. engine 11 to tank 1
The heat sent to the engine 11 can be sent, for example, as exhaust gas of the engine 11 or cooling water heated by the engine, but it is also possible to use a fluid that exchanges heat with them.

In order to control the amount of heat for heating the metal hydride in the tank 10, the feed path 12 that feeds heat from the engine 11 to the tank 10 is provided with a feed amount control means 13. As shown in the figure as an example, this feeding heat amount control means 13 is provided with a flow rate control valve 14 in the feeding path 12 and branches a bypass path 15 between the engine 11 and its flow rate control valve 14. , the bypass passage 15 may also be provided with a flow rate control valve 1B.

Further, the tank 10 is provided with a pressure sensor 17 for detecting the pressure of hydrogen gas stored therein, and an arithmetic and control device 18 is connected to the pressure sensor 17.

The arithmetic and control unit 18 determines the temporal change in pressure detected by the pressure sensor 17, that is, the pressure gradient, and controls the heat supply amount control means 13 according to the pressure gradient. The attached storage device 19 is provided with a reference map showing the correspondence between the pressure gradient and the opening degree of the flow rate control valve 14. By comparing and contrasting data with the data in the reference map, the unit 1 controls the amount of heat to be supplied using a control amount corresponding to the pressure gradient obtained thereby.
3, i.e. the flow control valve 14. This controls the opening degree of the till.

When controlling the opening degree of the flow rate control valves 14, 1B, the pressure level inside the tank detected by the pressure sensor 17 can also be taken into account. For example, when the pressure level inside the tank exceeds a preset pressure range, , it is possible to control the opening degrees of the flow rate control valves ta and te to be kept constant regardless of the above-mentioned pressure gradient.

In the metal hydride tank pressure control device having the above configuration, when the heat generated by the engine 11 is sent to the tank lO to heat the metal hydride, the amount of heat to be sent is controlled by the flow rate control valve by the arithmetic and control device 18. The hydrogen in the metal hydride tank 10 is controlled by the opening degree adjustment of the metal hydride tank 14. Gas pressure can be made to respond well to load fluctuations.

[Effects of the Invention] According to the pressure control device of the present invention, the pressure control in the metal hydride tank becomes predictive control, and the tank internal pressure can be kept almost constant with good responsiveness regardless of load fluctuations. This also improves the accuracy of measuring the amount of hydrogen supplied to a hydrogen gas combustion device such as an engine, thereby improving the functionality of the system. Furthermore, it is possible to prevent the tank internal pressure from becoming excessive during an emergency stop of the hydrogen gas combustion device, thereby increasing the safety of the system.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a metal hydride engine system equipped with the pressure control device of the present invention, and FIG. 2 is a block diagram of a general metal hydride engine system. DESCRIPTION OF SYMBOLS 10-- Tank, 11-- Engine 12, Φ feed path, 13-- Feeding heat amount control means, 17-- Pressure sensor, 18-- Arithmetic control device. Figure 1 Figure 2

Claims (1)

[Claims] 1. A tank containing a metal hydride and a hydrogen gas combustion device that uses the hydrogen gas occluded in the metal hydride as a fuel source, and the heat generated in the hydrogen gas combustion device is sent to the tank. In a hydrogen gas combustion system that heats a metal hydride, a means for controlling the amount of heat to be supplied is provided in the supply path for transmitting heat from the hydrogen gas combustion device to the tank, and the pressure of the hydrogen gas is controlled in the tank. A pressure sensor is provided to detect the pressure, and an arithmetic and control device is connected to the pressure sensor for determining the temporal change in the pressure detected by the pressure sensor and controlling the above-mentioned heat supply amount control means in accordance with the temporal change. Features: Pressure control device for metal hydride tanks.