阅读说明：本技术 金属氢化物压缩机控制装置和方法 (Metal hydride compressor control apparatus and method ) 是由 诺里斯·加兰达特 安德烈亚斯·祖特尔 于 2018-11-16 设计创作，主要内容包括：本发明涉及一种用于产生可变的输出压力P<Sub>_desired_outPut</Sub>的金属氢化物压缩机控制方法,该方法包括：第一步,使气态氢流入到在恒定温度下的金属氢化物隔室中,并且然后停止气态氢的流入；第二步,将金属氢化物加热到预定温度,该预定温度对应于在期望的输出压力P<Sub>_desired_output</Sub>下穿过α+β相的温度；第三步,打开压缩机的输出连接并通过调节温度使其保持在恒定的压力下,以保持恒定的输出压力P<Sub>_desired_outPut</Sub>直到系统完全离开α+β相。(The invention relates to a device for generating a variable output pressure P _desired_outPut The method of controlling a metal hydride compressor, the method comprising: a first step of flowing gaseous hydrogen into a metal hydride compartment at a constant temperature and then stopping the flow of gaseous hydrogen; a second step of heating the metal hydride to a predetermined temperature, the predetermined temperatureThe temperature corresponds to the desired output pressure P _desired_output Down through the α + β phase, and a third step of opening the compressor output connection and maintaining it at a constant pressure by regulating the temperature to maintain a constant output pressure P _desired_outPut Until the system completely leaves α + β phases.)

1. For generating variable output pressure P_{_desired_output}The metal hydride compressor control method of (a), said method comprising:

a first step of flowing gaseous hydrogen into a metal hydride compartment at a constant temperature and then stopping the flow of gaseous hydrogen;

second, the metal hydride is heated to a predetermined temperature corresponding to a desired output pressure P_{_desired_output}Temperature of the lower pass α + β phase;

third, the compressor output connection is opened and maintained at a constant pressure by adjusting the temperature to maintain a constant output pressure P_{_desired_output}Up toThe system completely exited the α + β phase.

2. The metal hydride compressor control method as claimed in claim 1, wherein the first step further comprises cooling the metal hydride to maintain a temperature of the metal hydride constant.

3. The metal hydride compressor control method as claimed in claim 1 or 2, wherein the first step is continued until the boundary of the α + β phase is reached.

4. The metal hydride compressor control method as claimed in any one of claims 1 to 3, wherein, during step 3,

5. the metal hydride compressor control method according to any of claims 1 to 4, wherein the temperature regulation is achieved by a control method selected from the group consisting of PID control, MIMO control or control by any number of inputs and outputs and different sensing means.

6. A metal hydride compressor control method as claimed in any of claims 1 to 5, characterized in that the connection to the source of gaseous hydrogen is closed by using some closing means, such as a mechanical or electrical valve or any other closing means.

7. A metal hydride compressor control method according to any of claims 1 to 6, where the output connection of the compressor is opened by some opening/closing means, such as a valve or any other electrical, mechanical or electromechanical system.

8. The metal hydride compressor control method as claimed in any one of claims 1 to 7, wherein at the end of the third step, when H is₂Having been fully output, the output connection is closed and the system is cooled.

9. A metal hydride compressor control method according to any of claims 1 to 8, characterized in that at the end of cooling another cycle is started again, possibly by selecting a different temperature T3 in the second step to create a different pressure than in the previous cycle.

10. A metal hydride compressor adapted to operate in accordance with the metal hydride compressor control method as claimed in any one of claims 1 to 9.

11. The metal hydride compressor of claim 10, wherein the metal hydride compartment is adapted for continuous operation.

12. The metal hydride compressor of claim 10 or 11, wherein the metal hydride compressor is a multi-stage metal hydride compressor.

13. The metal hydride compressor of claim 12, wherein each stage comprises a different alloy in series to produce a higher compression ratio.

Technical Field

The present invention relates to a metal hydride based compressor, and more particularly to a unipolar or multistage metal hydride based compressor with variable output pressure.

Background

Metal hydrides are commonly used to store hydrogen at low pressures because many metals and alloys can reversibly absorb large amounts of hydrogen. The hydrogen molecules are dissociated (dissociated) at the surface before being absorbed, and the two H atoms recombine into H during desorption (desorption)₂. The thermodynamic aspects of the formation of hydrides from gaseous hydrogen are described by the pressure-composition isotherms (pressure-composition isotherms) shown in fig. 1, as well as by other features known to those skilled in the art.

The graph shows a pressure-concentration-temperature graph on the left side and the logarithm of the equilibrium or plateau pressure versus the reciprocal of the temperature on the right side. The alpha phase is the phase before absorption, and the beta phase is the phase at which the metal H is saturated. In the α + β phase, the pressure varies exponentially with temperature. At the desired plateau temperature, heat is provided to the metal hydride to initiate the desorption process and release gaseous hydrogen at the desired pressure.

Different configurations of metal hydride compressors have been disclosed. There are metal hydride compressors that operate using a single metal alloy, as well as multi-stage compressors that combine different alloys to allow higher compression ratios to be achieved. There are compressors that operate in batch mode, as well as compressors that operate continuously. All compressors operate between a set of discrete temperature/pressure levels, which means that they all have a fixed compression ratio.

For example, document WO 2012114229 proposes a metal hydride compressor comprising one or more interconnected compression modules and comprising a gas distribution system and a heat transfer system comprising a hot fluid system and a cold fluid system for heating and cooling, respectively. The compressor is thermally driven using a control system that operates switches in the flow system and a circulation pump. The control system operates the two compression modules at opposite, identical times to achieve a continuous outflow of pressurized hydrogen. Metal hydride compressors operate at a fixed compression ratio.

Furthermore, document EP 2391846 relates to a device for operating a plurality of compression modules simultaneously. Furthermore, at moderate temperature levels, excess heat is permanently removed from the heat sink side.

Furthermore, document WO 2003006874 discloses a combined mass storage/single stage metal hydride compressor, hydrogen storage alloy and hydrogen delivery/distribution system. The device is used for bulk storage of hydrogen and for compression of the hydrogen to a level greater than or equal to 1500psi at a temperature less than or equal to 200 ℃.

Finally, document DE102005004590 describes a cyclically operating metal hydride compressor, which is disclosed for use in motor vehicles. The cyclically operated metal hydride compressor includes a pressure-resistant tank filled with metal hydride, and cyclically absorbs or desorbs hydrogen gas.

One of the main problems with the devices of these documents is that none of these devices is capable of delivering variable pressures.

It is therefore a primary object of the present invention to provide a compressor based on single-pole or multi-stage metal hydrides with variable output pressure and a method of driving the same.

Disclosure of Invention

The above problems are solved by the present invention.

A first aspect of the invention relates to a method for generating a variable output pressure P_{_desired_output}The method of controlling a metal hydride compressor, the method comprising: a first step of flowing gaseous hydrogen into the metal hydride compartment at a constant temperature and then stopping the flow of gaseous hydrogen; in a second step, the metal hydride is heated to a predetermined temperature corresponding to a desired output pressure P_{_desired_output}Temperature of the lower pass α + β phase;

in a third step, the compressor output connection is opened and maintained at a constant pressure by regulating the temperature in order to maintain a constant output pressure P_{_desired_output}Until the system completely leaves α + β phases.

According to a preferred embodiment of the invention, the first step further comprises cooling the metal hydride to keep the temperature of said metal hydride constant.

Preferably, the first step is continued until the boundary of the α + β phase is reached.

Advantageously, the temperature regulation is achieved using a control method selected from PID control, MIMO control or control by any number of inputs and outputs and different sensing means.

According to a preferred embodiment of the invention, some closing means, such as a mechanical or electrical valve or any other closing means, is used to close the connection to the gaseous hydrogen source.

Advantageously, some opening/closing means, such as a valve or any other electrical, mechanical or electromechanical system, is used to open the output connection of the compressor.

Preferably, at the end of the third step, when H2 has been fully output, the output connection is closed and the system is cooled.

According to a preferred embodiment of the invention, another cycle is started again at the end of the cooling, possibly by selecting a different temperature T3 in a second step to create a different pressure than in the previous cycle.

A second aspect of the invention relates to a metal hydride compressor adapted to operate according to the metal hydride compressor control method of the first aspect of the invention. The particular advantages of the apparatus of the present invention are similar to those of the method of the first aspect of the present invention and will not be repeated here.

Advantageously, the metal hydride compartment is adapted for continuous operation.

Preferably, the metal hydride compressor is a multi-stage metal hydride compressor.

According to a preferred embodiment of the invention, each stage comprises a series of different alloys to create a higher compression ratio.

Drawings

Other particular advantages and features of the invention will become more apparent from the following non-limiting description of at least one embodiment of the invention, with reference to the accompanying drawings, in which

FIG. 1 shows the pressure-component isotherm curve of the process of the invention with a Van't Hoff diagram.

Detailed Description

This detailed description is intended to explain the invention in a non-limiting manner, since any feature of an embodiment may be combined in an advantageous manner with any other feature of a different embodiment.

The present invention relates to a method for controlling a single or multi-stage metal hydride compressor, wherein the compression ratio is not fixed but can be varied or adjusted by the user.

More specifically, by controlling the temperature using the method of the present invention, the hydrogen effluent pressure can be adjusted to a desired level within a range of values. The single or multi-stage metal hydride compressor control method comprises a first step of flowing gaseous hydrogen into a metal hydride compartment at a constant temperature T1 ═ T2 while cooling the metal hydride, which cooling method may be passive, such as by ambient convection, or may be active, such as by some liquid cooling path or forced air convection. In fig. 1, this step is represented as a state of moving from point 1 along the isotherm until the boundary of the α + β phase is reached at point 2.

Temperature is monitored using, for example, a thermocouple or RTD, and pressure is monitored using a conventional pressure sensor. Once point T2 is reached, the flow of gaseous hydrogen is stopped and some closing means (e.g., a mechanical or electrical valve or any other closing means) is used to close the connection to the source of gaseous hydrogen.

At this point, in a second step, the metal hydride is heated to some pre-calculated or on-line calculated temperature T3 at point 3 of FIG. 1T3 corresponds to a pressure at the desired output pressure P_{_desired_output}Temperature of the lower pass α + β phase in FIG. 3, this is represented by the vertical line connecting point 2 and point 3 temperature T3 is based on various parameters, but the most important parameters are the material used and the desired output pressure P_{_desired_output}。

Once the desired output pressure P is reached due to heating to T3_{_desired_output}The compressor output connection is opened using some opening/closing device, such as a valve or any other electrical, mechanical or electromechanical system, and the system is kept at a constant pressure by regulating the temperature. In fact, since the desorption reaction is endothermic, additional heat must be supplied to the system to keep the pressure constant.

The adjustment may be achieved using any control method, including: proportional, integral and derivative (PID) control; multiple input, multiple output (MIMO) control or control through any number of inputs and outputs and different sensing devices, including in particular one or more temperature and pressure sensing devices.

The system then moves along the isotherm starting at point 3 and at some point the system will again enter the α + β phase.

The system is then maintained at a suitable temperature to ensure a constant output pressure P_{_desired_output}Until leaving α + β phase at point 4.

When said latter step is completed, i.e. when H₂Having been fully output, the output connection is closed and the system cools to point 1, at which point 1 the cycle begins again, possibly creating a different pressure than in the previous cycle by selecting a different temperature T3 in step 2.

Another aspect of the invention relates to a single-stage or multi-stage metal hydride compressor in which the above-described method is performed. The single-stage or multi-stage metal hydride compressor has a variable output pressure P_{_desired_output}The variable input being controlled by the use of temperature in one or more zones of the devicePressure P_{_desired_output}Is kept constant (or variable according to some determined function of time).

According to a preferred embodiment, the metal hydride compressor is a multi-stage metal hydride, wherein each stage comprises a different material and receives the desired P_{_desired_output}As input from a previous stage.

Such compressors may be used in applications requiring variable compression ratios, including but not limited to: a compressor for a laboratory, the compressor providing compressed and/or purified hydrogen for use in the experiment; compressors for industrial hydrogen compression applications; a compressor for the hydrogen station; and compressors for hydrogen or metal hydride energy storage systems including fuel cells and/or electrolyzers.

While embodiments have been described in conjunction with a number of embodiments, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the applicable arts. Accordingly, the present disclosure is intended to embrace all such alternatives, modifications, equivalents and variations as fall within the scope of the present disclosure. This may be particularly the case, for example, for the exact temperatures used, the materials used, the monitoring system, the number of stages, the temperature sensors and all the different devices, which may be used in connection with the invention.