JPH0623629B2 - Control method for air conditioning system using metal hydride - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for controlling an air conditioner using a metal hydride.

(B) Conventional Technology As a conventional method for controlling an air conditioner using a metal hydride, for example, there is one disclosed in Japanese Patent Publication No. 58-19954. That is, a compressor is provided between two heat exchange type metal containers containing different amounts of metal hydride, the flow of hydrogen gas is repeatedly reversed by this compressor, and cooling is performed via the metal container in which hydrogen is being released. Also, heating is performed through a metal container in which hydrogen is being stored.

(C) Problems to be Solved by the Invention However, in the conventional method for controlling an air conditioner using a metal hydride as described above, a compressor is always operated to supply hydrogen gas to a metal container on either side. Since it is moved from the metal container to the metal container on the other side, there is a problem that the energy consumed by the compressor is large. That is, there is a problem that the amount of heat obtained is small with respect to the energy input to the compressor, and the thermal efficiency is not good. The present invention aims to solve such problems.

(D) Means for Solving the Problems The present invention utilizes the difference between the hydrogen equilibrium pressure of one metal hydride heat exchanger and the hydrogen equilibrium pressure of the other metal hydride heat exchanger, The above problem is solved by providing a process for moving hydrogen gas without using a compressor. That is, in the method for controlling an air conditioner using a metal hydride according to the present invention, one set of the metal hydride heat exchanger (10) is filled with a metal hydride having a low hydrogen saturation, and the other set of the metal hydride heat exchanger (10) is filled with a metal hydride. The metal hydride heat exchanger (12) is filled with metal hydride having a high degree of hydrogen saturation, and hydrogen gas is transferred from the other set of metal hydride heat exchangers to the other set of metal hydride heat exchangers. Of the metal hydride heat exchanger of the other set is higher than the hydrogen equilibrium pressure of the metal hydride heat exchanger of the other set, the compressor is set to no-load operation and the compressor is moved. A hydrogen gas is moved by the pressure difference between the heat exchangers for both metal hydrides, and the hydrogen equilibrium pressure of the heat exchangers for the other metal hydride Heat exchanger hydrogen After the equilibrium pressure is reached, the bypass passage is closed and the hydrogen gas is moved by the compressor. When one of the metal hydrides reaches a predetermined saturation level, the hydrogen flow is reversed and Repeat the operation. The reference numerals in parentheses indicate the corresponding members in the embodiments described later.

(E) Action For example, when used as a heating device, the compressor is first put into a no-load operation state, and at the same time, the bypass passage has one set of heat exchanger for metal hydride and the other set of metal hydride. Connect with the heat exchanger. The hydrogen equilibrium pressure of the metal hydride in the other set of hydride heat exchangers is higher than the hydrogen equilibrium pressure of the metal hydride in the other set of metal hydride heat exchangers. The movement starts automatically. As a result, heat is generated in the other set of metal hydride heat exchangers, and the heat medium passage of the metal hydride heat exchanger is connected to the heat medium passage of the indoor heat exchange unit. Further, heat absorption is performed in the metal hydride heat exchanger of the one set, and the heat medium passage of the metal hydride heat exchanger is connected to the heat medium passage of the heat source heat exchange unit. Thus, a predetermined amount of hydrogen gas moves, and when the hydrogen equilibrium pressure of the other set of metal hydride heat exchangers becomes equal to the hydrogen equilibrium pressure of the other set of metal hydride heat exchangers, the flow of hydrogen gas changes. To stop, the bypass passage is closed and the compressor moves the hydrogen gas from the other set of metal hydride heat exchangers to the other set of metal hydride heat exchangers. When the transfer of a predetermined amount of hydrogen gas from the other set of metal hydride heat exchanger to the other set of metal hydride heat exchanger is completed, the flow of hydrogen is reversed and at the same time both heat exchangers and both heat exchange Perform the same operation by reversing the combination of unit connections. Thereby, heating is continuously performed in the indoor heat exchange unit, and heat is absorbed in the heat source heat exchange unit. As described above, the compressor is in a no-load operation state while hydrogen gas flows through the bypass passage, so compared to the conventional one in which the compressor was always operated in a load state, the input energy The efficiency of the amount of heat increases significantly.

(F) Example An example of the present invention is shown in FIGS. A metal hydride heat exchanger 10 and a metal hydride heat exchanger 12 move a hydrogen gas compressor 14, and hydrogen gas valves 41, 42, 43, 44, 45, 46, 47 and 48.
Are connected by the valve 4 as shown in FIG.
By controlling the opening and closing of 1, 42, 43, 44, 45, 46, 47 and 48, hydrogen gas can be moved between the metal hydride heat exchanger 10 and the metal hydride heat exchanger 12. Although the metal hydride heat exchanger 10 and the metal hydride heat exchanger 12 are filled with metal hydride, the metal hydride heat exchanger 10 has a hydrogen saturation level as shown in FIG. A metal hydride having a low (B ₀ point) (equilibrium temperature T ₁ ) is filled, and the metal hydride heat exchanger 12 has a high hydrogen saturation (A ₀ point) as shown in FIG. Filled with hydride (equilibrium temperature T ₂ ). The metal hydride heat exchanger 10 and the metal hydride heat exchanger 12 are provided with pressure detectors 15 and 17, respectively, which detect the hydrogen gas pressure. The heat medium passage 16 in the metal hydride heat exchanger 10 and the heat medium passage 18 in the metal hydride heat exchanger 12 are the heat medium passage 22 of the heat source heat exchange unit 20 and the indoor heat exchange unit. Two
4 is connected to the heat medium passage 26 as shown in FIG. In the middle of the piping, as shown in the drawing, valves 31, 32, 33, 34, 35, 36, 37 and 3 for heat medium are used.
8 and pumps 27 and 29 are provided. Operation of the compressor 14, valves 41, 42, 43, 44, 4
Opening and closing 5, 46, 47 and 48 and valves 31, 3
Opening / closing of 2, 33, 34, 35, 36, 37 and 38 is performed by a command from a control device (not shown).

Next, the operation of this embodiment when operated as a heating device will be described.

First, as the first step, the hydrogen gas pressure of the metal hydride heat exchanger 12 reaches the point of A ₀ , and the metal hydride heat exchanger 1
When the pressure detectors 15 and 17 detect that the hydrogen gas pressure of ₀ has reached the state of B ₀ , step A shown in FIG. 7 is started, the compressor 14 enters the no-load operation state, and the valve 43, 46, 48 and 44 are open and valves 41, 42, 45 and 47 are closed. At the same time, the valves 35, 36, 37 and 38 are opened and the valves 31, 32, 33 and 34 are closed. This state is shown in FIG. In this state, the heat medium flows between the heat source heat exchange unit 20 and the metal hydride heat exchanger 12, and the heat medium flows between the indoor heat exchange unit 24 and the metal hydride heat exchanger 10. It will flow. At this time, the hydrogen gas equilibrium pressure of the metal hydride heat exchanger 12 is A _0.
Since the hydrogen gas equilibrium pressure of the metal hydride heat exchanger 10 is B ₀ , a relatively large differential pressure is generated between the two and the valve 42, regardless of the compressor 14,
Hydrogen gas of the metal hydride heat exchanger 12 moves to the metal hydride heat exchanger 10 side through a passage bypassing the compressor 14 constituted by the valve 48, the valve 46, and the valve 41. As a result, the hydrogen gas pressure in the metal hydride heat exchanger 12 decreases along A ₀ → B _1, and the hydrogen gas pressure in the metal hydride heat exchanger 10 along B ₀ → A _1. Going up. The hydrogen gas pressure of the metal hydride heat exchanger 12 becomes Pe at B ₁ point, and the hydrogen gas pressure of the metal hydride heat exchanger 10 is Pe at A ₁ .
Then, the differential pressure between the metal hydride heat exchanger 12 and the metal hydride heat exchanger 10 disappears, and the movement of hydrogen gas stops. Reaching this state means that the pressure detectors 15 provided in the metal hydride heat exchangers 10 and 12 respectively.
And 17 (note that it is also possible to detect that the flow rate of hydrogen gas is 0 by a flow meter provided in the bypass passage to detect that this state is reached). When the hydrogen gas pressures of the metal hydride heat exchanger 10 and the metal hydride heat exchanger 12 become equal to each other as described above, step B is started, and the compressor 14 is put into the load operation state again and the valve 43 is operated. , 45, 47
And 44 are opened and valves 41, 42, 46 and 48 are closed. On the other hand, the valves 31 to 38 retain the previous states. That is, the valves 35, 36, 37 and 38 are opened and the valves 31, 32, 33 and 34 are closed. This state is shown in FIG. As a result, the hydrogen gas equilibrium pressure of the metal hydride heat exchanger 12 is B ₁ → B _0.
The hydrogen gas equilibrium pressure of the metal hydride heat exchanger 10 changes along A ₁ → A ₀ . During this period, heat is generated in the metal hydride heat exchanger 10, and heat is absorbed in the metal hydride heat exchanger 12, whereby heat is dissipated in the indoor heat exchange unit 24 and the heat source heat exchange unit 20. The heat is absorbed by. The hydrogen gas equilibrium pressures reach the states of B ₀ and A ₀ , respectively.

As a second stage, the pressure sensor 1 indicates that the hydrogen gas pressure of the metal hydride heat exchanger 10 has reached the point of A _{0 and} the hydrogen gas pressure of the metal hydride heat exchanger 12 has become the state of B _0.
5 and 17, the compressor 14 in which step A has been started is in the no-load operation state, the valves 41, 46, 48 and 42 are opened, and the valves 43, 4
4, 45 and 47 are closed. Valve 35, 3 at the same time
6, 37 and 38 are opened and valves 31, 32, 33 are
And 34 are closed. This state is shown in FIG. In this state, the heat medium flows between the heat source heat exchange unit 20 and the metal hydride heat exchanger 10, and the heat medium flows between the indoor heat exchange unit 24 and the metal hydride heat exchanger 12. It will flow. At this point, the hydrogen gas equilibrium pressure of the metal hydride heat exchanger 12 is A ₀ and the hydrogen gas equilibrium pressure of the metal hydride heat exchanger 10 is B ₀ , so a relatively large differential pressure between the two. Is generated and the hydrogen gas in the metal hydride heat exchanger 10 passes through the passage bypassing the compressor 14 constituted by the valve 42, the valve 48, the valve 46 and the valve 41 irrespective of the compressor 14. It moves to the heat exchanger 12 for chemicals. As a result, the hydrogen gas pressure in the metal hydride heat exchanger 10 decreases along A ₀ → B _1, and the hydrogen gas pressure in the metal hydride heat exchanger 12 follows B ₀ → A _1. Going up. When the hydrogen gas pressure of the metal hydride heat exchanger 10 becomes Pe at point B _{1 and} the hydrogen gas pressure of the metal hydride heat exchanger 12 becomes Pe at A ₁ , the metal hydride heat exchanger 10 And heat exchanger for metal hydrides 1
The pressure difference from 2 disappears and the movement of hydrogen gas stops. The fact that this state has been reached is detected by the pressure detectors 15 and 17 provided in the metal hydride heat exchangers 10 and 12, respectively (note that the flow rate of hydrogen gas is 0 by a flow meter provided in the bypass passage). It is also possible to detect that it has reached this state by detecting). When the hydrogen gas pressures of the metal hydride heat exchanger 10 and the metal hydride heat exchanger 12 become equal to each other as described above, step B is started to bring the compressor 14 into the load operation state again and the valve 41. , 42, 45 and 47 open,
The valves 43, 44, 46 and 48 are closed. On the other hand, the valves 31 to 38 retain the previous states. That is, the valves 35, 36, 37 and 38 are opened and the valves 31, 32, 33 and 34 are closed. This state is shown in FIG. Thereby, the heat exchanger 1 for metal hydride
The hydrogen gas equilibrium pressure of ₀ changes along B ₁ → B _0, and the hydrogen gas equilibrium pressure of the metal hydride heat exchanger 12 is A ₁ →
Changes along A ₀ . During this time, heat is generated in the metal hydride heat exchanger 12, and the metal hydride heat exchanger 10
Heat is absorbed in the indoor heat exchange unit 2
Heat is dissipated at 4, and heat is absorbed at the heat source heat exchange unit 20. When the hydrogen gas equilibrium pressures reach the states of B ₀ and A ₀ , respectively, the initial first stage is restored again. Hereinafter, the first step → the second step is similarly repeated. FIG. 7 shows the change in the hydrogen transfer amount and the change in the shaft power of the compressor 14 in the steps A and B. In step A, a predetermined amount of hydrogen gas is moved even though the compressor 14 is not driven at all. During this time, the amount of heat can be acquired without inputting energy to the compressor 14, and the ratio of the amount of heat acquired in one cycle to the amount of work of the compressor 14, that is, the coefficient of performance, is significantly improved compared to the conventional method.

(G) Effect of the Invention As described above, according to the present invention, when there is a differential pressure of the hydrogen gas equilibrium pressure between the two heat exchangers for metal hydride, the operation of the compressor is stopped and Since the hydrogen gas is moved, the amount of heat acquired can be increased with respect to the energy input to the compressor.
The thermal efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a cooling and heating apparatus to which the method of the present invention is applied, FIGS. 2 and 3 are diagrams showing a first stage of the cooling and heating apparatus shown in FIG. 1, and FIGS. 4 and 5 are cooling and heating apparatuses shown in FIG. FIG. 6 is a diagram showing the second stage of FIG.
FIG. 7 is a diagram showing changes in the hydrogen transfer amount and the shaft power of the compressor. 10 ... Metal hydride heat exchanger, 12 ... Metal hydride heat exchanger, 14 ... Compressor, 16 ... Heat medium passage, 18 ... Heat medium passage, 20 ... Heat source heat exchange Unit, 24 ... Indoor heat exchange unit.

Claims (1)

[Claims] 1. A compressor for moving hydrogen gas between two sets of heat exchangers for metal hydrides, and one set of heat exchangers for metal hydrides and the other set of heat exchangers for metal hydrides. A valve for hydrogen gas for controlling the moving direction of hydrogen gas, a heat medium passage for two sets of metal hydride heat exchangers, and a heat medium passage for an indoor heat exchange unit and a heat source heat exchange unit. In a method for controlling an air conditioner using a metal hydride having a valve for a heat medium for switching the connection between the two, a heat exchanger for metal hydride of one set is filled with a metal hydride having low hydrogen saturation. , The other set of metal hydride heat exchangers is filled with highly saturated metal hydride, and the other set of metal hydride heat exchangers changes from one set of metal hydride heat exchangers to When moving the hydrogen gas, While the hydrogen equilibrium pressure of the metal hydride heat exchanger is higher than the hydrogen equilibrium pressure of one set of metal hydride heat exchangers, the compressor is put into no-load operation and a passage bypassing the compressor is formed. The hydrogen gas is moved by the pressure difference of the metal hydride heat exchanger, and the hydrogen equilibrium pressure of the other set of metal hydride heat exchangers is equal to the hydrogen equilibrium pressure of the other set of metal hydride heat exchangers. After that, the bypass passage is closed and the hydrogen gas is moved by the compressor.When the metal hydride of one set reaches a predetermined saturation level, the hydrogen flow is reversed and the same operation is repeated. A method for controlling an air conditioner using a metal hydride, which is characterized by continuous operation.