JPS61134551A - Metallic hydride heat pump device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to heat pump equipment that utilizes the endothermic and exothermic action of metal hydrides and hydrogen. can absorb hydrogen and produce metal hydrides. Therefore, metal hydrides are metals that can absorb hydrogen (
(also referred to as hydrogen storage alloy). In this case, a large amount of hydrogen is absorbed per unit weight of the metal, and the hydrogen is released reversibly at the ring temperature used.

) Also, the process of releasing hydrogen from a metal hydride is an endothermic reaction, and conversely, the process of absorbing hydrogen is an exothermic reaction.

Furthermore, since this hydrogen absorption and release reaction proceeds reversibly, a cooling device using this principle (Special Publication No. 6 B-199
Tsuno's cooling system proposed 66), which connects two heat-exchangeable metal containers containing two types of metal hydrides with different hydrogen equilibrium pressures via automatic valves, etc., and connects them to the low-pressure side using various heat sources. A device or its basic cycle is proposed, in which hydrogen is released from a metal hydride on the high-pressure side, the hydrogen is released from the metal hydride on the high-pressure side, a metal container is used to obtain a low temperature, and this low-temperature total heat exchanger is used for cooling, etc. This conventional cycle requires a heating temperature above a certain standard level in order to generate a low temperature in the high-pressure metal hydride. However, there are cases where it is not always possible to obtain a heat source at the required temperature level, especially when using waste heat sources or solar heat sources, which are important from the perspective of energy conservation, and the temperature range of the heating source becomes unstable. When the heating temperature falls below a certain temperature level, the hydrogen transfer head becomes smaller, the amount of hydrogen transfer, which is closely related to the amount of heat, decreases and the transfer speed becomes slower. Therefore, the efficiency is significantly reduced, the amount of low temperature obtained is reduced, and the cooling capacity of an air conditioner is reduced.

Problems to be Solved by the Invention Conventional devices and cycles are used to obtain low temperatures for air conditioning, etc., and when a metal hydride is selected, the temperature range of the heating source needs to be higher than a certain temperature standard. If the temperature is lower than that, it becomes difficult to efficiently obtain the desired low temperature.

Therefore, an object of the present invention is to provide a metal hydride heat pump cycle or a device thereof that generates a desired low temperature even if the heating source temperature changes. In particular, it can be applied to applications where the heat source temperature is relatively unstable, such as industrial waste heat or solar heat.

Means for Solving the Problems In order to solve the above problems, the present invention provides metal hydrides having different hydrogen equilibrium pressures, such as low pressure (MHl).

Using medium-pressure (MH2), high-pressure (MHs), etc., the medium-pressure (MH2) metal hydride is heated at the above-mentioned hydrogen equilibrium pressure, and the hydrogen in MH2 is converted into the low-pressure (MHI) metal hydride. The storage heat transferred to the other low pressure (
After raising the temperature of the MH4 metal hydride, the first
In one mode, a pressure difference is formed by the amount of heat generated by the temperature rise of MH1', and hydrogen increases in MH1 due to the pressure difference.
Takes a clockwise cycle moving from to MHs. Second
This is a metal hydride heat pump device that simultaneously performs a counterclockwise cycle in which the hydrogen stored in MHIK is further transferred to MH2.The metal hydride (for high pressure) with the highest hydrogen equilibrium pressure generates a low temperature and cools the air. The present invention forms two types of heat pump cycles, one between low pressure and medium pressure, and one between low pressure and high pressure, and exchanges heat between the heat pump cycles. As a result, heat higher than the heating temperature can be obtained by the movement of hydrogen, and a predetermined low temperature can be obtained even if an unstable heat source is used.

Embodiment The present invention has a function of efficiently obtaining stable low and medium temperatures even if the maximum heating source temperature fluctuates due to the above-described configuration. Next, this effect will be explained in detail.

FIG. 1 is a diagram showing the relationship between hydrogen equilibrium pressure and temperature characteristics, showing the heat pump cycle of the present invention. The vertical axis shows the hydrogen equilibrium pressure (atmospheric pressure), PM ) PH, > P) F) PH”
) PM') The pressure decreases in the order of P L >PM'. On the other hand, the horizontal axis is the temperature (1ooo/T ton, TH)
The temperature decreases in the order of TM) TM/) TL. In the same figure, the medium pressure (MH2) metal hydride is heated to reach the pressure PM (1a atm) and temperature TM (ao'c), and the hydrogen in MH2 is transferred to the low pressure (MHl) metal hydride with a pressure difference ( PM)PH), and the temperature is TH(12
0"C) and generates a temperature higher than the heat source temperature: TM. Using this high temperature, heat another low-pressure metal hydride (MH1) to a temperature of TH (about 120°C). Hydrogen is transferred from MH1' to MHs with a pressure difference of PH (1 o atm)) PH' (s atm), and maintained at temperature TM/ by the heat of absorption of MHs, and when all the hydrogen is transferred to MHs, As a process, the pressure difference PL (2 atm)) PM' (0.5 atm) from MHs to MH1' is
1'(7) Hydrogen moves while maintaining the temperature TM'(30"C) and the MHs temperature TL (ooC). Therefore, a low temperature of 0°C can be obtained in the MHs part. On the other hand, the hydrogen transferred from MH2 to MHL is further PH'' (e atm)) PM'' (4 atm pressure difference and T
At the temperature of M (go"c), TM'(3o"C),
A cycle is taken to move from MHI to MH2. By operating these two cycles simultaneously, it is possible to create a low temperature TL even at a temperature TM lower than TH.

In the conventional cycle mentioned above, hydrogen is converted into MH by heating MHL.
Because it is a single cycle of MHL-MH3, in which hydrogen is transferred to I, MH3, and hydrogen is transferred from MH3 to MHL, a heat source of TH or higher is definitely required. Figure 2 uses the heat pump cycle shown in Figure 1. FIG. 1 is a block diagram showing an example of a metal hydride heat pump device. In Figure 2, during operation in the first mode, 1 is a heating source, 2 is a metal container containing medium pressure metal hydride 3 (MH2), and 4 is a metal container containing low pressure metal hydride s (MHl). container,
Both metal containers 2.4 are connected via an automatic valve 6 with a hydrogen transfer pipe. A heat exchanger 10 is installed to transfer heat between the metal container 4 and the other metal container 9 containing a low-pressure metal hydride B (MHI') via a pump 11 for circulating the heat medium. The metal container 9 is connected to a metal container 13 containing a high-pressure metal hydride 12 (MH3) via an automatic valve 14 and a hydrogen transfer pipe 16. The metal container 13 is provided with a heat exchange pipe 16 for heat radiation.

Also included is a liquid or gas heat exchanger 17 for heating the MH2.

In the second mode of operation, the heat exchange pipe 18 for heat radiation cools the MH2. MHI has a heating exchanger 19°MHI'
Also heat exchange pipe for heat radiation 20. When hydrogen moves from the metal hydride MH3 contained in the metal container 13 to MH1' due to the pressure difference, the metal hydride MH3 is cooled by the endothermic action of MHs. The entire low temperature heat exchanger 23 can be passed through the low temperature heat exchanger 23 through the cooling pump 22 and used for cooling.

Here, high-pressure NH3 is used as an example of metal hydride.

: TiMn1.5Hy= , MH2 for medium pressure: LaN
15 Hz, low pressure MH1: LaNL4Cu Hz was used. As for the alloy weight, MH2 and MHL for heating (second mode side) are used more than metal hydride on the first mode side,
Efficient heat transfer has been achieved. Using a heat medium (oil) heated by gas combustion as a heating source, "TM"
When heating 30"C to TM80°C and transferring hydrogen from MH2 to MHL, the temperature reaches TH120°C,
The same effect was obtained with a heating source temperature of 80°C as with a heating temperature of 120'C. With this storage temperature of MHL, M
H1'.

is heated and hydrogen is transferred from MH1' to MH3 with a pressure difference (PH) PH7), and then the temperatures of TM/ in Figure 1 ■ and ■
By holding it at the point #), hydrogen naturally moves from MH3 to MH1' with a mere pressure difference (PL) PM').

At this time, MH3 (7) temperature TM'30'C to TLO''
I was able to get it down to C. By exchanging heat, this low temperature can be used for cooling purposes.

Hydrogen in MHI moves to MH2 and is regenerated, and becomes MH2 again.
A similar cycle is constructed by heating the water at a temperature of TMso'C.This time, we use four containers to generate a high temperature from the heating source and obtain a low temperature. By combining one set of containers with one or more sets, it is possible to continuously obtain low temperatures.

In this way, we have given an example where low temperature can be used for air conditioning, but it can also be used for cold water supply. In addition, in the example, TM'i was set at 30°C as an example, but it is also possible to set it at 50°C. The use of metal hydrides allows cycling in different temperature ranges of TH)TM)TM')TL. Here, if the heating source is a waste heat source or solar heat source that contains unstable elements, it will not be possible to secure a sufficient temperature, so if the heat pump device of the cycle of the present invention is used, it has the function of increasing the temperature, so the temperature can be increased. If it is insufficient, add the cycle of ■-■-■'-■'-■.If sufficient temperature can be secured at TH,
It is sufficient to use only the cycle -■-■-■-■. Both cycles can be used efficiently depending on the temperature of the heating source, and therefore a noiseless and efficient heat pump can be constructed, thus providing an excellent device from the viewpoint of energy saving.

In this embodiment, a gas heat source was used as a substitute for waste heat, but other heat sources may be used.

Effects of the Invention As described above, according to the present invention, it is possible to obtain the same low temperature even if the temperature range of the heating source changes, so it is possible to heat unstable heat sources such as waste heat, solar heat, etc. It has a great effect in that it can be used as an energy-saving heat pot as a heat source.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between hydrogen equilibrium pressure and temperature, showing the configuration of a metal hydride heat pump in an embodiment of the present invention, and Figure 2 is a block diagram showing the configuration of a metal hydride heat pump device in an embodiment of the present invention. It is a diagram. 1... Heating source, 3... Metal hydride for medium pressure, 5°8... Metal hydride for low pressure, 12.
...Metal hydride for high pressure, 6.14 ... Automatic valve, 10 ... Heat exchanger for heat transfer, 2,4,9
．． 13...Metal container, 21...--Heat exchanger for low temperature medium. Name of Deputy 7: Patent attorney Toshio Nakao and one other person Figure 1: 5L degree (too Geno PM'---6 medium 7FL---/2θ ・
Fr'1'---4"PL---2"PM'---0,5 etc.

Claims (1)

[Claims] The medium pressure metal hydride is heated, and the different low pressure metal hydrides are raised in temperature using storage heat that transfers hydrogen in the medium pressure metal hydride to the low pressure metal hydride, and as a first mode, the different low pressure metal hydrides are heated. As a second mode, a pressure difference is formed by the amount of heat generated by the temperature rise of the metal hydride for use, and hydrogen moves from the metal hydride for low pressure to the metal hydride for high pressure using the pressure difference, and as a second mode, A metal hydride heat pump device characterized in that hydrogen occluded in the low-pressure metal hydride is further transferred to the medium-pressure metal hydride at the same time.