JPH109709A - Heat-driven metal hydride adsorption refrigerator - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the energy efficiency of a metal hydride refrigerator. SOLUTION: A heat driven metal hydride adsorption refrigerator having three pairs of high temperature side and low temperature side reactors is provided for each pair.
The operation is performed in three modes of a hydrogen charging mode, a cooling mode, and a refrigeration output mode shifted by 0 degrees. Valves are respectively arranged on the pipes connecting the respective reactor pairs. In the hydrogen filling mode, the heat source heats the high temperature side reactor, in the cooling mode, the cooling circuit cools the high temperature side reactor, and also in the hydrogen filling and cooling mode, the cooling circuit cools the low temperature side reactor. A circuit supplies refrigerant to the cold side reactor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD OF THE INVENTION

[0002]

2. Description of the Prior Art As disclosed in, for example, EP 0 131 869 B1, a heat driven metal hydride adsorption heat pump is known. The metal hydride generates heat when absorbing (adsorbing) hydrogen, and conversely absorbs heat when the metal hydride releases hydrogen. This endothermic effect is used as a refrigerating effect.

A refrigerator having four reactors will be described with reference to FIG. The high temperature side reactors HT1 and HT2 and the low temperature side reactors NT1 and NT2 are connected via pipes 101 and 102, respectively, and two pairs of reactors P1 (HT1 & NT1), P2
(HT2 & NT2). An appropriate amount of hydrogen is sealed in each of the reactor pairs P1 and P2, and the high-temperature side reactors HT1 and HT2 and the low-temperature side reactor NT are connected via pipes 101 and 102, respectively.
1 and NT2. Valves VW1 and VW2 are provided in the middle of the pipes 101 and 102, respectively, so that the flow of hydrogen can be shut off. In the high-temperature side reactors HT1 and HT2, a fant shown in FIG.
A high-temperature metal hydride (hydrogen storage alloy) having a characteristic as shown by 103 in a Hof curve is accommodated therein, and low-temperature metal hydride (hydrogen storage alloy) also having a characteristic as shown by 104 is accommodated in the low-temperature side reactors L1 and L2. To accommodate.

The heat transport circuit 110 includes a heat source 111 and a passage 1
12 and a pump 113. As the heat source 111, for example, in addition to a chemical plant and a heat treatment process (such as a blast furnace), exhaust gas heat of an automobile can be used. In this case, the refrigerator is used as an air conditioner of the automobile. The heat transport circuit 110 selectively supplies the heat of the heat source 111 to one of the high-temperature side reactors HT1 and HT2. The valves VH1E, VH2E, VH1A and VH2A are shown in FIG.
Is switched to the position a or the position b based on the valve position.

When the valves VH1E and VH1A are at the position a, the high temperature side reactor HT1 is heated, and the valves VH2E and VH2V
If H2A is at position a, the high temperature side reactor HT2 is heated. The heat of the heat source 111 flows through the passage 112 via a heat transfer medium such as water or as the exhaust gas itself.
If the heat transport circuit is a closed loop circuit, the pump 113
Is required.

The cooling circuit 120 includes a cooling water pipe 121, a pump 122, and a radiator (radiator) 123.
One of the high-temperature side reactors HT1 and HT2 is cooled. When the valves VH1E and VH1A are at the position b, the high temperature side reactor HT1 is cooled, and when the valves VH2E and VH2A are at the position b, the high temperature side reactor HT2 is cooled. As the cooling medium, for example, water is used. Cooling circuit 120
Also cools one of the low-temperature side reactors NT1 and NT2. If the valves VN1E and VN1A are at the position b, the low temperature side reactor NT1 is cooled and the valves VN2E and VN2V
If N2A is at the position b, the low temperature side reactor NT2 is cooled. The valves VN1E, VN2E, VN1A, and VN2A are also switched to the a position or the b position based on the valve position in FIG.

The refrigerant circuit 130 has a refrigerant pipe 131, a pump 132, and a heat exchanger 133. Valve VN1
When E and VN1A are at the position a, the refrigerant is supplied to the low-temperature side reactor NT1. When the valves VN2E and VN2A are at the position a, the refrigerant is supplied to the low-temperature side reactor NT2. The blower circuit 140 has a blower 141 and a switching valve 142. The air supplied by the fan 114 is the heat exchanger 1
It is cooled in 33 and blown out into the chamber 143. When the switching valve 142 is at the position a, the room air is supplied to the blower circuit 140.
And fresh air is supplied from outside if it is at position b.

[0008] Each of the reactors HT1, HT2, NT1,
At least two liquid-tightly and air-tightly separated chambers are formed in the NT2, one of which is provided with a metal hydride and into which hydrogen can flow, and the other of which has a heat transfer medium, cooling water,
One of the refrigerants flows as appropriate depending on the position of the valve.

Each reactor pair P1, P2 has an operating mode of 18
It is shifted by 0 degrees. That is, the reactor pair P1 is in phase 1:
Hydrogen filling mode (reactor NT1) and hydrogen release mode (reactor HT1) followed by phase 2: standby mode (reactor NT1) and cooling mode (reactor HT1)
Even when there is no refrigeration output, the reactor pair P2 is in the refrigeration output mode (reactor NT
2) and hydrogen adsorption mode (reactor HT2). Conversely, the reactor pair P1 is in the refrigeration output mode (reactor NT1) and the hydrogen adsorption mode (reactor HT1) in both phases 3 and 4, but the reactor pair P2 is in the phase 3: hydrogen filling mode (reaction Reactor NT2) and hydrogen release mode (reactor HT2), followed by phase 4:
There is no refrigeration output in the standby mode (reactor NT2) and the cooling mode (reactor HT2). Therefore, a refrigeration output is always obtained for the entire system.

The operation of each phase will be described below.
As described above, since the operation modes of the reactor pairs P1 and P2 are shifted from each other by 180 degrees, only the reactor pair P1 will be described.

Phase 1 is a hydrogen filling mode of the low temperature side reactor NT1. The high temperature side reactor HT1 is in the hydrogen release mode, the valves VH1E and VH1A are at the a position, and the valves VH2E and VH2A are at the b position, so that heat from the heat source is supplied only to the high temperature side reactor HT1. This state is as shown in FIG. Therefore, the high temperature side reactor HT1
The hydrogen occluded in the low-temperature side reactor NT1 is released through the pipe 101 by being given heat from the outside.
Is filled with hydrogen. At this time, the valves VN1E and VN1
A is at position b, and cooling water supplied by the cooling water circuit flows through the low-temperature reactor NT1. As shown in FIG. 18, the inlet temperature TH1E of the high-temperature side reactor HT1 rises, for example, to 150 degrees Celsius, and the outlet temperature TH1A also rises to 15 degrees Celsius.
It rises to 0 degrees. Inlet temperature TN of low temperature side reactor NT1
1E remains at 35 degrees Celsius, while its exit temperature T
N1A temporarily rises to 60 degrees Celsius, but falls to the inlet temperature TN1E (= 35 degrees Celsius) by the end of Phase 1. This effect occurs in phase 3 for reactor pair P2 in exactly the same way.

When the low-temperature side reactor NT1 is filled with hydrogen, the process proceeds to phase 2. Phase 2 is the high-temperature side reactor HT
In this cooling mode, the valve VW1 arranged on the pipe 101 of the reactor pair P1 is closed (see FIG. 16).
The valves VH1E and VH1A are switched to the position b, and the valves VH2E and VH2A are kept at the position b. The high temperature side reactor HT1 is cooled by the cooling water supplied by the cooling water circuit, and nothing happens because the low temperature side reactor NT1 is in the standby mode. Since the valve VW1 is closed, the hydrogen charged in the low-temperature side reactor NT1 remains as it is. The valves VN1E and VN1A remain at the b position. As shown in FIG. 18, the outlet temperature TH1A of the high temperature side reactor HT1 drops to its inlet temperature TH1E equal to the cooling water temperature by the end of the phase 2. This effect occurs in phase 4 exactly as for reactor pair P2.

Next, both phases 3 and 4 are in the refrigeration output mode. Valve VW1 is opened. The valves VH1E and VH1A remain at the position b. On the other hand, the valves VN1E and VN1A are switched to the position a. Looking at the low-temperature side reactor NT1, it removes the heat of the refrigerant flowing in the reactor NT1 and releases hydrogen. When the refrigerant is used, the heat is deprived, that is, the refrigerant is cooled, and the air supplied by the fan 114 in the heat exchanger 133 is cooled. The hydrogen released from the low-temperature side reactor NT1 passes through the pipe 101, and the high-temperature side reactor H
Adsorbed on T1. As shown in FIG. 18, the outlet temperature TH1A of the high-temperature side reactor HT1 temporarily rises to 75 degrees Celsius, but by the end of the phase 3, the inlet temperature TH1E of the high-temperature side reactor HT1 equal to the cooling water temperature. Descend to Although the outlet temperature TN1A of the low temperature side reactor NT1 temporarily decreases to 6 degrees Celsius, it increases to the inlet temperature TN1E as the phases 3 and 4 progress. This effect occurs in phase 1 and 2 exactly the same for reactor pair P2.

The heat pump having the above four reactors has the following disadvantages.

First, in phase 2, the valves VH1E,
All of VH1A, VH2E, VH2A are at position b,
The heat of the heat source is not used at all. From the viewpoint of using the exhaust heat, it is preferable that the exhaust heat is always used as a system.

Second, as apparent from FIG. 18, it is in phases 3 and 4 that the reactor pair P1 produces a refrigeration output.
As is clear from the curve L1 showing the outlet temperature Ta of the low-temperature side reactor NT1, shortly before the end of the phase 3, the refrigeration output has already been reduced, and up to the phase 4, the refrigeration output is extremely small. However, phase 4 is essential for cooling the high-temperature side reactor HT2 of the reactor pair 2, and when considered as a system, phase 4 and phase 2 cannot substantially expect a refrigeration output, that is, a system standby state. Becomes

Third, the hydrogen adsorption / desorption rate of the metal hydride is the fastest at the beginning of the adsorption / desorption mode, that is, at the beginning of the phase, and decreases with time. In obtaining a refrigeration output, it takes a lot of time to make maximum use of the hydrogen adsorbed in the low-temperature side reactor, that is, to release the hydrogen to the maximum. However, the refrigeration output of the system is obtained by dividing the time required to utilize the hydrogen energy used in one cycle, and there is an optimum value for the refrigeration output. When operating the system for optimal refrigeration output, the time to use hydrogen energy is shorter than the time to release the adsorbed hydrogen to the maximum, so that all of the hydrogen energy of the system is not used. And the coefficient of performance (COP) deteriorates. For example, as shown in FIG. 10, the time of the phases 3 and 4 in which the reactor pair P1 obtains the refrigeration output is 422 seconds, and the energy obtained in the 422 seconds is 78% of the total energy.
It only uses percentages.

[0018]

Accordingly, an object of the present invention is to improve the energy efficiency of a metal hydride refrigerator.

[0019]

Means for Solving the Problems A first technical means of the present invention taken to solve the above-mentioned technical problems is an operation mode comprising a hydrogen filling mode, a cooling mode and a refrigeration output mode, and a high-temperature side operation mode. And a low-temperature side reactor pair, a valve disposed on a pipe communicating the pair of reactors, a heat source for heating the high-temperature side reactor in the hydrogen charging mode, and a high-temperature side reactor in the cooling mode, hydrogen filling and In a heat-driven metal hydride adsorption refrigerator having a cooling circuit for cooling the low-temperature side reactor in the cooling mode and a refrigerant circuit for supplying a refrigerant to the low-temperature side reactor in the refrigeration output mode, the high-temperature side and the low-temperature That is, three side reactor pairs were provided, and the operation cycles of the three reactor pairs were shifted by 120 degrees.

In order to solve the above-mentioned technical problem, a second technical means according to the present invention is characterized in that, in addition to the above-mentioned first technical means, a refrigeration output mode end of the operation mode is set in a pre-cooling mode. It was that.

The third technical means of the present invention taken to solve the above-mentioned technical problem is that, in addition to the above-mentioned first technical means, the initial hydrogen filling mode of the operation mode is referred to as a preheating mode. It was done.

(Operation) According to the first technical means described above, the three high-temperature side and low-temperature side reactor pairs operated in the operation mode consisting of the hydrogen filling mode, the cooling mode and the refrigeration output mode are set to 120 degrees. It is operated in a mode cycle shifted by one. A valve is arranged on a pipe connecting the reactor pairs, and shuts off hydrogen communication between the reactor pairs in the cooling mode. In the hydrogen filling mode, the heat source heats the hot side reactor. The cooling circuit cools the high-temperature side reactor in the cooling mode, and cools the low-temperature side reactor in the hydrogen filling and cooling mode. In the refrigeration output mode, the refrigerant circuit supplies the refrigerant to the low temperature side reactor.

According to the second technical means described above, the low-temperature side reactor in the pre-cooling mode pre-cools the refrigerant flowing into the low-temperature reactor in the refrigeration output mode.

According to the third technical means described above, the heat of the heat source that has heated the high-temperature side reactor of the pair of reactors in the hydrogen charging mode is subsequently supplied to the high-temperature side reactor of the pair of reactors in the preheating mode. Heat.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A refrigerator 10 having six reactors according to an embodiment of the present invention will be described with reference to FIG. High temperature side reactors HT1, HT2, HT3 and low temperature side reactors NT1, NT
2 and NT3 are connected via pipes 11, 12 and 13, respectively, and three reactor pairs P1 (HT1 & NT1), P2
(HT2 & NT2) and P3 (HT3 & NT3).
The high-temperature side reactors HT1, HT2, and HT3 accommodate high-temperature metal hydrides (hydrogen storage alloys) having characteristics as indicated by 103 in the Fant-Hof curve shown in FIG.
The same applies to the low-temperature side reactors NT1, NT2 and NT3.
A low-temperature metal hydride (hydrogen storage alloy) having the characteristics shown in Fig. 1 is housed. An appropriate amount of hydrogen is sealed in the system of each of the reactor pairs P1, P2, and P3.
High-temperature side reactors HT1, HT
2, HT3 and the low-temperature side reactors NT1, NT2, NT3. Piping 11, 12,
Valves VW1, VW2, and VW3 are respectively disposed in the middle of 13, so that the flow of hydrogen can be shut off.

Heat transfer medium piping 14, pump 15, heat source 16
Of the high-temperature side reactor H
T1, HT2, and HT3 can be appropriately heated. As the heat source 16, for example, in addition to a chemical plant or a heat treatment process (such as a blast furnace), if this refrigerator is used as an air conditioner of an automobile, heat of exhaust gas of the automobile can be used.
That is, the refrigerator 10 enables recovery and use of exhaust heat. However, the heat source 16 does not necessarily need to be a waste heat source. In FIG. 1, the heat transfer medium pipe 14 has a loop shape, and a pump 15 is provided in the middle of the loop. This is a case where exhaust heat of a chemical plant or a heat treatment process is used as a heat source. . The heat transfer medium pipe 14 does not necessarily need to be in a loop shape, and the pump 15 need not necessarily be provided if the heat transfer medium pipe 14 is not in a loop shape. This is apparent when utilizing exhaust gas heat of a vehicle as a heat source. That is, in this case,
The heat transfer medium is a high-temperature exhaust gas, and the heat transfer medium pipe 14 is an exhaust pipe.

The heat from the heat source 16 passes through the heat transfer medium pipe 14 via a heat transfer medium such as water, and flows through the valves VH1E and VH1E.
VH2E, VH3E, VH1A, VH2A, VH3A
(Hereinafter referred to as “high-temperature reactor-side valve group”), and is appropriately supplied to the high-temperature reactors HT1, HT2, and HT3. The high temperature reactor side valve group is based on the valve position in FIG.
The position is switched to the position, the b position or the c position. Valve V
H1E, VH1A, (VH2E, VH2A), (VH3
When the position of (E, VH3A) is at the position a, the high-temperature side reactors HT1 (HT2) and (HT3) are heated.

By the operation of a cooling circuit 24 comprising a cooling water pipe 21, a pump 22, and a radiator (radiator) 23, the high temperature side reactors HT1, HT2, HT3 and the low temperature side reactors NT1, NT2, NT3 are respectively cooled by cooling water. It can be cooled. By the action of the high-temperature reactor side valve group, the cooling water of the cooling circuit 24 is supplied to the high-temperature reactors HT1, HT2, H
It is supplied to T3 as appropriate. Similarly, valves VN1E and VN
2E, VN3E, VN1A, VN2A, VN3A (hereinafter referred to as "low-temperature reactor side valve group"), the cooling water of the cooling circuit 24 is cooled by the low-temperature reactors NT1, NT2, NT3.
Are also supplied as appropriate. The low temperature reactor side valve group is also switched to the position a, the position b or the position c based on the valve position in FIG.

Refrigerant pipe 31, pump 32, heat exchanger 33
Thus, a refrigerant circuit 34 is formed. Air supplied by a fan 35 is guided to the heat exchanger 33, and the air is cooled by a refrigerant. The cooled air is used for a refrigerating device typified by, for example, an indoor air conditioner and cools the room 36. When the valve 37 is at the position a, the air in the chamber 36 circulates to the heat exchanger 33, and when the valve 37 is at the position b, outside air is guided to the heat exchanger 33. Heat exchanger 33
Or may be directly disposed in a closed space such as the room 33. By the operation of the low-temperature reactor side valve group, the refrigerant circuit 34
Is appropriately supplied to the low-temperature side reactors NT1, NT2, NT3.

As shown in FIG. 5, each reactor HT1, HT
2, HT3, NT1, NT2, NT3, at least two liquid-tightly and air-tightly isolated chambers 41, 42 are formed, respectively. The high temperature metal hydride having the characteristic shown by the curve HT-MH in FIG. 6 is accommodated in the chamber 41 of each high temperature side reactor, and absorbs hydrogen. Similarly, a low-temperature metal hydride having a characteristic indicated by a curve NT-MH in FIG. 6 is accommodated in the chamber 41 of each low-temperature side reactor, and stores hydrogen. The chamber 42 selectively receives any one of the heat transfer medium, the cooling water, and the refrigerant. However, no refrigerant flows in the chamber 42 of each high-temperature side reactor, and no heat transfer medium flows in each chamber 42 of each low-temperature side reactor. The chamber 42 has buffer spaces 43 and 44, a pipe 45
Is provided. Inlets 46 and 47, which also function as outlets, are connected to chamber 41, and inlet 48 and outlet 49 are connected to chamber 42.

Temperature sensors TH1A, TH2A, TH3A
Respectively detect the temperature of the heat transfer medium or the cooling water flowing out of the high-temperature side reactors HT1, HT2, HT3, and
A, TN2A, TN3A are low-temperature side reactors NT1, NT
2. The temperature of the cooling water or the refrigerant flowing out of the NT3 is detected. Similarly, temperature sensors TH1E, TH2E, TH3E
Respectively detect the temperature of the heat transfer medium or the cooling water before flowing into the high-temperature side reactors HT1, HT2, HT3,
1E, TN2E, TN3E are low-temperature side reactors NT1, NT
2. Detect the temperature of the cooling water or the refrigerant before flowing into NT3. In addition, the temperature sensor TU has a radiator 23 atmosphere,
The temperature sensor TKabin detects the temperature inside the chamber 36.

The operating mode of each reactor pair P1, P2, P3 is shifted by 120 degrees. That is, as shown in FIG. 7, the refrigerator 10 having six reactors has nine operation phases, and the phases 1 to 9 of the reactor pair P1 correspond to the phases 4 to 9 of the reactor pair P2, respectively. 9,
1 to 3, and the reactor pair P3 corresponds to phases 7 to 9, 1 to 6. Then, in phases 3 to 5, a refrigeration output is obtained from the low-temperature side reactor NT1 of the reactor pair P1, and in phases 6 to 8, the reactor pair P2 is obtained.
, A refrigeration output is obtained from the low-temperature side reactor NT2 of the reactor pair P3, and a refrigeration output is obtained from the low-temperature side reactor NT3 of the reactor pair P3 in the phases 9 and 1-2. can get.

The operation of each phase will be described below.
As described above, the reactor pairs P1, P2, and P3 have their operation modes shifted only by 120 degrees from each other.
Will be described only.

(1) Low-Temperature Reactor Hydrogen Filling Mode Phases 7, 8, 9, and 1 are the low-temperature-side reactor NT1 hydrogen filling mode. In each phase, all valves are in the positions shown in FIG. Phase 7 is, in particular, a preheating mode of the high-temperature side reactor HT1, in which heat from the heat source is not directly supplied to the high-temperature side reactor HT1 via the heat transfer medium, but from the valve position diagram of FIG. As is clear, the heat transfer medium flowing through the high-temperature side reactor HT3 is
1 is supplied. Although the state of phase 7 is not shown in any of FIGS. 1 to 3 for the high-temperature side reactor HT1, the high-temperature reactor HT2 shown in FIG. 1 corresponds to this.

In phases 8, 9, and 1, the high-temperature side reactor HT1 is in the hydrogen release mode, and the heat transfer medium is directly supplied from the heat source to the high-temperature side reactor HT1. In phases 8 and 9, the heat transfer medium flows directly from the heat source 16 into the hot side reactor HT1. This is because only the valves VH1E and VH1A of the high temperature side reactor HT1 are set to the a position, and all valves related to the other high temperature side reactors are set to the b position. The states of phases 8 and 9 are not shown in any of FIGS. 1 to 3, but correspond to the high-temperature reactor HT2 shown in FIG.

FIG. 1 shows the state of phase 1. The heat transfer medium flowing through the high-temperature side reactor HT1 is subsequently supplied to the high-temperature side reactor H
It also flows to T2 and preheats the hot side reactor HT2. That is, in the hydrogen filling mode composed of four phases, in the final phase (phase 1 in this case), the high-temperature side reactor H
The heat transfer medium flowing through Tx is followed by the high-temperature side reactor HTx + 1
Flows through. Here, x is any one of the reactor pair numbers 1 to 3, and x + 1 = 1 only when x = 3.

In phases 7, 8, 9, and 1, the hydrogen stored in the high-temperature metal hydride of the high-temperature side reactor HT1 releases hydrogen by being given heat from the outside,
The hydrogen is charged into the low-temperature metal hydride of the low-temperature side reactor NT1 via the pipe 11. At this time, the low temperature side reactor N
Cooling water is always supplied to T1 by the action of the cooling water circuit 24.

As shown in FIG. 8, the high temperature side reactor HT
The outlet temperature TH1A of No. 1 is about 53 degrees Celsius at the beginning of Phase 7. The outlet temperature TH1A rises rapidly to 150 degrees Celsius by the middle of Phase 9. on the other hand,
The outlet temperature TN1A of the low temperature side reactor NT1 is about 34 degrees Celsius at the beginning of the phase 7. This outlet temperature TN1A
Temporarily rises to about 53 degrees Celsius by the end of Phase 8, but falls to 37.5 degrees Celsius by the end of Phase 1.

The hydrogen filling mode of the low temperature side reactor NT1 composed of the phases 7, 8, 9, and 1 is the same as the hydrogen filling mode of the low temperature side reactor NT2 in the phases 1, 2, 3, and 4 in the reactor pair P2. Correspondingly, phase 4 in reactor pair P3
5, 6, and 7 correspond to the hydrogen filling mode of the low temperature side reactor NT3.

(2) Cooling Mode of High-Temperature Reactor When the hydrogen filling mode of the low-temperature reactor NT1 in which the phase 1 is the final phase ends, the phase shifts to phase 2. Phase 2 is a cooling mode of the high-temperature side reactor HT1, in which the valve VW1 arranged on the pipe 11 of the reactor pair P1 is closed (see FIG. 9). As can be seen from FIG. 7, at the start of phase 2, the cooling water temperature at the outlet side of the high-temperature side reactor HT1 is slightly lower than 150 ° C., but at the end of phase 2, the cooling water temperature decreases to about 100 ° C. I have. FIG. 2 shows the state of phase 2. Valve VH1E,
VH1A is switched to the b position, and the high temperature side reactor HT1
Is cooled by the operation of the cooling water circuit 24, and nothing happens because the low-temperature side reactor NT1 is in the standby mode. Since the valve VW1 is closed, the hydrogen charged in the low-temperature metal hydride of the low-temperature side reactor NT1 remains as it is. The valves VN1E and VN1A remain at the b position.

As is clear from FIG. 5, the cooling mode of the high-temperature side reactor HT1 composed of the phase 2 corresponds to the cooling mode of the high-temperature side reactor HT2 in the phase 5 of the reactor pair P2. In P3, phase 8 corresponds to the cooling mode of the high temperature side reactor HT3. And the reactor pair P
In valve 2, valve VW2 is closed only in phase 5, and in reactor pair P3, valve VW3 is closed only in phase 8. (See FIG. 9) (3) Refrigeration output mode of low-temperature side reactor Next, phases 3, 4, and 5 are refrigeration output modes of the low-temperature side reactor NT1. Valve VW1 is opened. Valve V
H1E and VH1A remain at the b position. FIG. 3 shows the state of phase 3. In phase 3, valve VN1
E is switched to the c position and VN1A is switched to the a position. On the other hand, in phases 4 and 5, the valves VN1E and VN1
Both A are switched to the a position. Therefore, Phase 3
In, the refrigerant pre-cooled by flowing through the low-temperature side reactor NT3 is supplied to the low-temperature side reactor NT1, and in phases 4 and 5, the refrigerant is directly supplied from the pump 32 to the low-temperature side reactor NT1. In any case, when the refrigerant flows in the low-temperature side reactor NT1, the hydrogen charged in the low-temperature metal hydride in the reactor NT1 deprives the refrigerant of heat and is released. Then, it reaches the high-temperature side reactor HT2 via the pipe 11, and is charged into the high-temperature metal hydride in the reactor HT2.
On the other hand, the refrigerant deprived of heat cools the air supplied by the fan 35 in the heat exchanger 33. The states of phases 4 and 5 of the low-temperature side reactor NT1 shown in FIG.
3 corresponds to this.

As shown in FIG. 8, the outlet temperature TH1A of the high-temperature side reactor HT1 is 10 degrees Celsius at the start of the phase 3.
0 degrees and drops to 55 degrees Celsius by the end of Phase 5. On the other hand, the outlet temperature TN1 of the low-temperature side reactor NT1
A is about 35 degrees Celsius at the beginning of Phase 3 and temporarily drops to 22 degrees Celsius by the end of Phase 3. And slowly by the end of Phase 5 26 Celsius
Rise to a degree.

The refrigeration output mode of the low temperature side reactor NT1 composed of the phases 3, 4 and 5 corresponds to the refrigeration output mode of the low temperature side reactor NT2 in the phases 6, 7 and 8 in the reactor pair P2. In the reactor pair P3, phases 9, 9, and 1 correspond to the refrigeration output mode of the low-temperature side reactor NT3.

(4) Pre-cooling mode of low-temperature side reactor Then, phase 6 is a pre-cooling mode of low-temperature side reactor NT1. However, it does not mean that the low-temperature side reactor NT1 is pre-cooled, but that the refrigerant flowing through the low-temperature side reactor NT1 is pre-cooled. The valve VN1E is switched to the position a, and the valve VN1A is switched to the position c. Therefore, in phase 6, the refrigerant pre-cooled by flowing through the low temperature side reactor NT1 is supplied to the low temperature side reactor NT2. That is, in the precooling mode, the refrigerant flowing through the low-temperature side reactor NTx subsequently flows through the low-temperature side reactor NTx + 1. Here, x is any one of the reactor pair numbers 1 to 3, and x + 1 = 1 only when x = 3. Although the state of phase 6 is not shown in any of FIGS. 1 to 3 for the low-temperature side reactor NT1, the low-temperature side reactor NT3 shown in FIG. 3 corresponds to this.

As is apparent from FIG. 8, the high temperature side reactor H
The exit temperature at T1 will drop from about 55 degrees Celsius to about 53 degrees Celsius by the end of Phase 6. On the other hand, the outlet temperature of the low temperature side reactor T1 slowly rises from about 26 degrees Celsius to about 34 degrees Celsius by the end of Phase 6.

The low-temperature side reactor N comprising the above phase 6
The pre-cooling mode of T1 corresponds to the pre-cooling mode of the low-temperature side reactor NT2 in the phase 9 in the reactor pair P2 and the reactor pair P3.
Corresponds to the pre-cooling mode of the low-temperature side reactor NT3 in phase 3.

Next, the switching timing of each phase will be described.

First, the termination criterion of the phase 1 is whether or not the difference between the outlet cooling water temperature TN1A and the inlet cooling water temperature TN1E of the low temperature side reactor NT1 becomes smaller than ΔT1 (TN1A−TN1E ≦ ΔT1). . That is, it is understood that the smaller the difference between the two is, the more the heat required to fill the low-temperature metal hydride with hydrogen in the low-temperature side reactor NT1 cannot be obtained. This indicates that the mode should be shifted to the cooling mode of the HT1. The value of ΔT1 varies depending on whether the refrigeration output of the system is maximized or the coefficient of performance COP is maximized, and also depends on various factors. For example, under a certain system, it is experimentally obtained as 2K. Was.
The termination criteria for phases 4 and 7 are also the reactor pair P2 and P2, respectively.
At P3, the outlet-side cooling water temperatures TN2A and TN3A of the low-temperature side reactors NT2 and NT3 and the inlet-side cooling water temperature TN2
It is whether the difference between E and TN3E has become smaller than ΔT1. In the general formula, TNxA−TNxE ≦ ΔT1, where x indicates the reactor pair number (1 to 3). Next, the termination criterion of the phase 2 is whether or not the outlet-side cooling water temperature TH1A of the high-temperature side reactor HT1 has become lower than the predetermined temperature THc (TH1A ≦ THc). Where THc
Is determined as follows. That is, if the temperature of the cooling water supplied from the pump 22 of the cooling water circuit 24 is, for example, 35 ° C., the temperature of the low-temperature side reactor NT1 is also 35 ° C.
Settle to ° C. At this time, as seen from FIG. 6, the internal pressure is about 13 bar, and the temperature corresponding to the internal pressure 13 bar of the high-temperature side reactor HT1 is about 100 ° C. This temperature is the predetermined temperature THc. Therefore, the predetermined temperature THc changes depending on the temperature of the cooling water supplied by the cooling water circuit 24. The termination criteria for phases 5 and 8 are also the same for the high-temperature side reactors HT2 and HT
3, the cooling water temperature TH2A, TH3A at the predetermined temperature T
It is whether it became smaller than Hc. In the general formula:
THxA ≦ THc, where x is the reactor pair number (1
3) are shown.

The termination criterion of phase 3 is whether or not the difference between the inlet-side refrigerant temperature TN3E and the outlet-side refrigerant temperature TN3A of the low-temperature side reactor NT3 becomes smaller than ΔT2 (TN3E−TN3A ≦ ΔT2). That is, as the difference between the two is smaller, it is understood that the refrigerant is not cooled in the low-temperature side reactor NT3, and the cooling capacity of the low-temperature side reactor NT3 is decreasing, and the reactor pair P3 is connected to the next low-temperature side reactor NT3. This indicates that the mode should be shifted to the hydrogen filling mode. The value of ΔT2 depends on whether the refrigeration output of the system is maximized or the coefficient of performance COP is maximized.
Also, depending on various factors, for example, under a certain system, it was experimentally determined to be 2K. The termination criteria for phases 6 and 9 are also the reactor pairs P1 and P2, respectively.
Of the low-temperature side reactors NT1 and NT2 of the low-temperature side reactors NT1 and NT2 and the outlet side refrigerant temperature TN1 of the low-temperature side reactors NT1 and NT2.
The determination is made by monitoring whether the difference between A and TN2A has become smaller than ΔT2. In the general formula, TNxE-
TNxA ≦ ΔT2, where x is the reactor pair number (1
3) are shown.

The degree of utilization of hydrogen energy will be examined. As shown in FIG. 10, in the case of the prior art four-reactor system, the phase in which the low-temperature reactor of a certain reactor pair obtains the refrigeration output is about 422 seconds, and the energy obtained in this time is all. About 78 percent of the energy. On the other hand, in the case of the six-reactor system according to the embodiment of the present invention,
The phase in which the cold side reactor of a certain reactor pair obtains a refrigeration output (= refrigeration output mode + pre-cooling mode) is about 436 seconds, and the energy obtained in about 430 seconds is about 92% of the total energy. Also reach.

When the exhaust heat source is automobile exhaust gas,
Let's look at the degree of utilization of waste heat. In the case of the four-reactor system of the prior art, as shown in FIG. 11, no waste heat is used in the phases 2 and 4, so the utilization efficiency is (used waste heat energy / total waste heat energy). (8
2kJ + 82kJ) / (82kJ + 82kJ + 32kJ)
+32 kJ + 36 kJ + 36 kJ) × 100 ≒ 55%. On the other hand, in the case of the six-reactor system according to the embodiment of the present invention,
As shown in FIG. 12, the utilization efficiency is similarly set to (238 k
J + 10 kJ) / (238 kJ + 10 kJ + 107 k)
J) × 100 ≒ 70%. That is, the waste heat utilization efficiency is improved by 15% as compared with the conventional one. Note that 6
The waste heat energy used in the reactor system (238 kJ
+10 kJ), the former 238 kJ is the amount of energy used and recovered by the high-temperature side reactor in the charging mode of the low-temperature side reactor, and the latter 10 kJ is the energy used and recovered by the pre-heating mode of the high-temperature side reactor. Quantity.

[0052]

According to the first aspect of the present invention,
Since three pairs of high-temperature and low-temperature reactors, which are operated in an operation mode including a hydrogen charging mode, a cooling mode, and a refrigeration output mode, are operated in a mode cycle shifted by 120 degrees each time, the entire system is always charged with hydrogen. Since there is a mode, the heat of the heat source can always be used and recovered, and since there is always a refrigeration output mode, a refrigeration output can always be obtained.

According to the second aspect of the present invention, the low-temperature side reactor in the pre-cooling mode preliminarily cools the refrigerant flowing into the low-temperature reactor in the refrigeration output mode.
As is clear from 0, the utilization rate of hydrogen energy increases. This precooling mode is located at the end of the refrigeration output mode, and the refrigeration output is small, and the refrigeration output is insufficient as it is.
Since it is used to cool the refrigerant flowing into the low-temperature side reactor in the middle stage, the refrigeration output can be used without waste.

According to the third aspect of the present invention, the heat of the heat source heating the high temperature side reactor of the pair of reactors in the hydrogen filling mode is subsequently changed to the high temperature side reactor of the pair of the reactors in the preheating mode. Is heated, so that the heat utilization rate of the heat source is increased as is apparent from the comparison between FIGS.

[Brief description of the drawings]

FIG. 1 is a system diagram of a heat-driven metal hydride adsorption refrigerator according to an embodiment of the present invention in a hydrogen filling mode.

FIG. 2 is a system diagram in a cooling mode of FIG. 1;

FIG. 3 is a system diagram in a refrigeration output mode of FIG. 1;

FIG. 4 is a valve position diagram in each phase of valves VN1E to VH3A in FIGS.

FIG. 5 is a partial sectional view of each reactor in FIG.

FIG. 6 is a Fant-Hof curve of a high-temperature side and a low-temperature side metal hydride accommodated in the reactor of FIG. 5;

FIG. 7 is a mode state diagram in each phase of each reactor in FIGS.

FIG. 8 is a diagram of each medium temperature in each phase of each reactor in FIGS.

FIG. 9 is a timing chart of closing each valve in FIGS.

FIG. 10 is an energy utilization diagram of each reactor in FIGS.

FIG. 11 is a utilization energy diagram of each reactor in the prior art.

FIG. 12 is a utilization energy diagram of each reactor in FIGS.

FIG. 13 is a system diagram in a hydrogen filling mode of a heat-driven metal hydride adsorption refrigerator according to the related art.

FIG. 14 is a system diagram in the cooling mode of FIG. 13;

FIG. 15 is a fant-Hof curve of a high-temperature side and a low-temperature side metal hydride accommodated in the reactor of FIGS. 13 and 14;

FIG. 16 shows valves VN1E to VH in FIGS.
It is a valve position figure in each phase of 2A, VW1, and VW2.

FIG. 17 is a mode state diagram in each phase of each reactor in FIGS.

FIG. 18 is a diagram of each medium temperature in each phase of each reactor in FIGS.

[Explanation of symbols]

HT1, HT2, HT3 ... High-temperature side reactor, NT1,
NT2, NT3: Low temperature side reactor pair, VW1, VW
2, VW3: valve, 16: heat source, 24:
Cooling circuit, 34 ... refrigerant circuit.

Claims (3)

[Claims] An operation mode comprising a hydrogen filling mode, a cooling mode, and a refrigeration output mode; a high-temperature side and a low-temperature side reactor pair; a valve disposed on a pipe communicating the pair of reactors; A heat source for heating the high-temperature side reactor in the cooling mode, a cooling circuit for cooling the high-temperature side reactor in the cooling mode, and a cooling circuit for cooling the low-temperature side reactor in the hydrogen filling and cooling modes, and supplying a refrigerant to the low-temperature side reactor in the refrigeration output mode. In the heat-driven metal hydride adsorption refrigerator including the refrigerant circuit, three high temperature side and low temperature side reactor pairs are provided, and the operation cycles of the three reactor pairs are shifted by 120 degrees. Features a heat-driven metal hydride adsorption refrigerator. 2. The heat-driven metal hydride adsorption refrigerator according to claim 1, wherein a last stage of the refrigeration output mode of the operation mode is a precooling mode. 3. The heat driven metal hydride adsorption refrigerator according to claim 1, wherein an initial stage of the hydrogen filling mode of the operation mode is a preheating mode.