JPS58182089A - Accumulated heat utilization system - Google Patents

Abstract

PURPOSE:To accelerate the heat transfer speed from low quality heat source by a structure wherein a plurality of hydrogen storage tank are installed with respect to one heat accumulator packed with metal hydride. CONSTITUTION:When collected solar heat quantity is not enough to actuate a heat energy load part 19, the heat transfer medium heated at a solar heat collector 18 is heat-exchanged by a heat exchanger 21 and the transferred heat is circulated in a heat transfer medium circulating piping 25. On the other hand, the heat transfer medium of the low quality heat source 12 is shifted through heat exchangers 15 and 7 to hydrogen storage tanks 2a, 2b, 2c and 2d so as to give the heat of said heat transfer medium to metal hydride M2H in order to resolve it for quickly releasing hydrogen. The released hydrogen is sent to the heat accumulator 1 so as to take part in the reaction M1+ H M1H+DELTAH. As a result, the heat quantity of DELTAH is produced and combined through a heat exchanger 17 with the heat energy collected in the solar heat collector 18 into the heat transfer medium in the circulating piping 25 and, after that, shifted through a heat exchanger 23 to heat transfer medium circulating in a heat transfer medium circulating piping 26 in order to actuate the heat energy load part 19. In addition, in case of the period of impossible solar heat collection such as during the night or the like, the enough heat for actuating the heat energy load part 19 is stored in a short term heat accumulator 20.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat storage utilization system that increases the rate of heat transfer from a low-quality heat source by installing a plurality of hydrogen storage tanks filled with metal hydride in one heat storage tank.

Certain metals and alloys are capable of storing hydrogen at densities equal to or higher than that of liquid hydrogen, and are attracting attention as new hydrogen storage materials. In addition, metal hydrides not only have the property of storing hydrogen, but also function as energy conversion materials that convert the chemical energy of hydrogen into heat or mechanical energy, allowing them to store and transport heat.

A heating, cooling, and hot water system that uses heat pumps and solar heat.

It is expected to be used as a medium in heat engines, compressors, pumps, etc. Regarding heat storage, the exchange function of chemical energy and thermal energy is used, but conventional sensible heat type and latent heat type heat storage materials have a heat storage amount of 40 to 70 cal/g (temperature difference). 60°C), whereas metal hydride (Mg2Ni)
al/g (excluding sensible heat), and is highly anticipated as a heat storage material.

A heat storage system using metal hydrides is currently in the development stage, but metal hydrides have a sufficiently rapid adsorption and dissociation reaction with hydrogen, but have extremely low heat conduction, so they are difficult to store and dissipate heat. It is difficult to get this done promptly.

In particular, as the heat storage capacity increases and one system becomes larger, the heat transfer rate becomes a serious problem, and when increasing the size of the system, it is not possible to simply increase the size.

This invention was made to solve the above-mentioned problem of low thermal conductivity of metal hydrides. A hydrogen storage system section consisting of a first heat exchanger and a group of branch conduits extending in a branch shape and reaching each hydrogen storage tank via on-off valves, and a hydrogen equilibrium dissociation pressure at the same temperature from the metal hydride in the hydrogen storage tank. A heat storage tank filled with a metal hydride with a low temperature and connected to a second exchanger, a main pipe that connects this heat storage tank and the trunk of the branch pipe group via a main opening/closing valve, and a second heat exchanger. It is equipped with a heat collection utilization system section connected through a heat exchanger, a cooling system section and a low-quality heat supply system section connected through a first heat exchanger, and operates the main on-off valve and each on-off valve as appropriate. The present invention provides a heat storage utilization system configured to utilize heat storage by operating a cooling system section when there is a surplus of heat collection and a low-quality heat supply system section when there is a shortage of heat collection.

In the system of this invention, a single heat storage tank is divided into a plurality of hydrogen storage tanks to increase the rate of heat transfer from a low-quality heat source. Furthermore, the system of the present invention has the advantage that the number of hydrogen storage tanks in operation can be changed according to the required amount of regenerated heat, and that the hydrogen storage tanks can be repaired or replaced without stopping operation.

FIG. 1 shows a schematic system diagram of the heat storage utilization system of the present invention when one solar heat collection utilization system is used as the heat collection utilization system section.

(1) is a heat storage tank filled with metal hydride, (2a
), (2b), (2a), and (2d) are a plurality of hydrogen storage tanks filled with metal hydrides, and these hydrogen storage tanks are connected to conduits (4a, 4b, 4c, 4d) with on-off valves (4a, 4b, 4c, 4d).
3a, 3b, 3c.

3d), and these hydrogen storage tank groups are connected to the heat storage tank (1)K by a main pipe (5) with a main on-off valve (6).

In addition, a common first heat exchanger (7) is connected to the hydrogen storage tanks (2a, 2b, 2c, 2d), and through this a cooling water injection pipe αα and a cooling water drain pipe αD are connected. A water supply system has been installed, as well as low quality heat sources (2) and conduits (13).
, 14), heat exchanger α5) and pump (16e, 16
A low quality heat supply system consisting of f) is installed.

On the other hand, the heat storage tank (1) has a second heat exchanger 0 connected to this button.
'7) A solar heat collection system has been installed. Group 0 is a solar heat collector, 09) is a thermal energy load unit such as air conditioning, heating, and hot water supply, (4) is a short-term heat storage device that uses water as a heat medium, N6m, 16b, 16c, 16d)
is a heat medium circulation pump, (21, 22, 23) is a heat exchanger, and (24, 25, 26) is a heat medium conduit.

This heat storage utilization system stores surplus thermal energy from solar heat collection over a long period of time during periods when demand for thermal energy is low, and regenerates thermal energy during periods when energy demand is high (for example, when air conditioning is required). It performs leveling, and the heat storage tank (1) K is CaNi5
Hydrogen storage tanks (2a, 2b, 2c, 2
d) is filled with a metal hydride, such as LaNi s hydride, which has a higher hydrogen equilibrium dissociation pressure at the same temperature than that filled in the heat storage tank (1). In addition, as a low-quality heat source, factory wastewater with a general VC of around 50°C is used.
The cooling system uses water at around 20°C.

Next, regarding the operation of this solar heat storage utilization system, the heat medium heated by the solar heat collector 01 is pumped (16 &
) circulates through the heat medium circulation pipe (2a) and connects the heat exchanger (
22) through the pump (16c) in the heat medium circulation line 12G).
), and the thermal energy load section 09 is operated by this heat medium.

In this case, the heat exchanger (23) is not operated. On the other hand, the surplus heat is exchanged via the heat exchanger (21) with the heat medium being circulated by the pump (16b) in the heat medium circulation pipe. Ru. Next, this surplus heat is transferred to the heat storage tank (1) K via the heat exchanger Q71. The hydrogen generated by the decomposition of the metal hydrides M and H in the heat storage tank (1) by this thermal energy opens the main on-off valve (6), and the on-off valves (4a, 4b, 4c, 4d) are activated as appropriate depending on the amount of excess heat. ) to the hydrogen storage tanks (2a, 2b, 2c, 2d) and the hydrogen conduits (5, 3a, 3b).

3c, 3d).

On the other hand, hydrogen generated by decomposition of MIH is stored in a hydrogen storage tank (
2g, 2b, 2c, 2d) to generate MzH and release reaction heat (however, the rate of heat release is slower than the heat release rate due to the hydrogenation reaction of Ml in the heat storage tank (1)). This reaction heat is absorbed by the cooling water through its injection pipe (by injecting it into the exchanger (7) and draining it through the drain pipe 0υ), and is transferred to the hydrogen storage tank (2a, 2b, 2c, 2d). Hydrogen is stored and excess heat is stored.

In this way, since this system is provided with a plurality of hydrogen storage tanks, a high heat transfer rate can be obtained, and the number of operating hydrogen storage tanks can be selected depending on the amount of surplus heat. Additionally, the hydrogen storage tank can be repaired or replaced while the system is in operation.

In this case, the thermal energy collected by the solar collector α is transferred to the thermal energy load section 0! M and H cannot be used directly in hydrogen storage tanks (2a, 2b, 2c, 2d).
Move the hydrogen stored as a heat storage tank (1)K and store it! The heat generated by the reaction with Ml in the tank (1) is utilized. Therefore, the heat medium heated by the solar heat collector α is transferred to the heat medium circulation path (goods) by the pump (16a).
The heat energy is exchanged by the heat exchanger (211) and transferred to the heat medium in the heat medium circulation pipe (2), and the heat medium is transferred to the heat medium circulation pipe (25+) by the pump (16b) K. [In this case, heat exchanger (2) does not operate].

On the other hand, the heat medium of the low-quality heat source 02 is circulated through the heat medium pipe line 03) by a pump (16f), and the heat is circulated through the heat medium pipe line side by the pump (16e) via the heat exchanger 05). The thermal energy is transferred to the medium and then transferred to the hydrogen storage tank (2a) via a heat exchanger (7).

2b, 2c, 2d) and given to the metal hydrides M, H and decomposed, and hydrogen is rapidly released. This hydrogen is
The on-off valves (4m, 4b, 4c, 4d) are opened as appropriate, and the main on-off valve (6) is moved to the heat medium. Thus, this thermal energy and the thermal energy collected by the solar collector ~Q81 described above are combined in the heating medium in the circulation line clsl, and then this thermal energy is transferred by the pump (16e) to the heating medium circulation line ( 2[i) The thermal energy is transferred to the heat medium circulating through the heat exchanger (23) to operate the thermal energy load section.

The heat medium heated by the solar heat collector for 0 seconds is circulated through the heat medium circulation pipe (goods) by the pump (16a), and is passed through the heat medium circulation pipe (□□□) through the heat exchanger @.
16d) to circulate the heat medium in the heat medium circulation pipe tube and operate the thermal energy load section a9, and also to operate the thermal energy load section 0 when heat cannot be collected from the sun such as at night.
9) is stored in the short-term heat storage device (4). Then, at night, the pump (16C) is stopped and only the pump (16d) is operated for a short period of time, and the stored heat is sent to the heat exchanger (20) to generate negative thermal energy. Ji'1 part (activate 1gl.

Since this system has multiple hydrogen storage tanks, a high heat transfer rate can be obtained, and an appropriate number of hydrogen storage tanks can be operated according to the required amount of regenerated heat. In cases where there is insufficient thermal energy to operate the thermal energy load section, the hydrogen storage tank (2a,
2b, 2e, 2d), the heat from the low-quality heat source α2 is transferred to the metal hydrides M and H and decomposed, resulting in hydrogen conduit hydrogen (3
a, 3b, 3c, 3d, 5), when the temperature of the heat storage hydride drops to the set temperature, open the on-off valve (4b), close the on-off valve (4a), and proceed to the next hydrogen storage tank (2b). The generated hydrogen is sent to the heat storage tank (1). Note that this set temperature is a temperature at which hydrogen can be transferred from the hydrogen storage tank to the heat storage tank with a sufficient pressure difference, and is selected as appropriate although it varies depending on the type of metal hydride used. The heat storage utilization system is controlled to open and close when the metal hydride in the hydrogen storage tank (2b) drops to the above-mentioned set humidity.

Then, the metal hydride in the hydrogen storage tank where the temperature of the metal hydride falls and the hydrogen supply is stopped is heated to a low-quality heat 1fIii temperature while the hydrogen supply is stopped, and is prepared for the next hydrogen supply.

In this system, the pressure of hydrogen sent to the heat storage tank (1) is high! It has the excellent advantage of being able to maintain a constant and sufficient hydrogen pressure difference between the hydrogen storage tank and the heat storage tank, and that the amount of heat generated per unit time in the heat storage tank is uniform and can be obtained at high humidity.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a solar heat storage utilization system according to an embodiment of the present invention. 11) --- Heat storage tank, (2a, 2b, 2c, 2d)-
Hydrogen storage tank, (5)...Hydrogen main pipe, (3", 3b
+3c, 3d) Hydrogen conduit, (6) Main on-off valve, (4a, 4b, 4c, 4d) On-off valve, (7
)...First heat exchanger, αηA, second heat exchanger, (1
0)...Cooling water pipe, 01)...Drainage pipe, (
12+...Low quality heat source, (13), C4),
(24+, Il, Iy3+ and □□□・・・・
Heat medium conductor, 15), C11+, (221o,
1: HiC23+-...Heat exchanger, (16a, 16
b, 16c, 16d, 16e, 16f, 1
6g1-Pump, 08)... Solar collector, 0
9)...Thermal energy load section and (4)...
Short-term heat storage.

Claims (1)

[Scope of Claims] 1. A plurality of hydrogen storage tanks filled with metal hydride, a first heat exchanger common to these hydrogen storage tanks, and a first heat exchanger common to these hydrogen storage tanks, extending in a branch shape and connected to each hydrogen storage tank via an on-off valve, respectively. A hydrogen storage system section consisting of a group of branch pipes leading to the hydrogen storage tank, and a heat storage tank filled with a metal hydride that has a lower hydrogen equilibrium dissociation pressure at the same temperature than the metal hydride in the hydrogen storage tank and connected to a second exchanger. , a main pipe that connects this heat storage tank and the trunk of the branch pipe group via a main on-off valve, a heat collection and utilization system section that is connected via a second heat exchanger, and a main pipe that connects the main pipe of the branch pipe group via a second heat exchanger. The main on-off valve and each on-off valve are operated as appropriate, and the cooling system section is activated when there is an excess of heat collection, and the low-quality heat supply system section is connected when there is an insufficient amount of heat collection. A heat storage utilization system configured to utilize heat storage by activating each button. 2. When the amount of heat collection is insufficient, only the on-off valve corresponding to one hydrogen storage tank of each on-off valve in the branch pipe group opens, and then when the temperature of the metal hydride in this hydrogen storage tank falls to the set temperature, that on-off valve opens. is closed and only the on-off valve corresponding to the other hydrogen storage tank is opened, and this operation is repeated so that hydrogen can be sent from each hydrogen storage tank to the heat storage tank in a sequential manner in a circulating manner. System described 0 7)