JPS6316019B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chemical heat pump that uses a combination of temperature cycles between a high temperature and high pressure state and a low temperature and low pressure state in each of the reversible reactions between two types of inorganic salts and a gas. For more details,
For each of the two types of reversible reactions, we separate the location where gas is decomposed and endothermicly reacted from the inorganic salt, which corresponds to high temperature and high pressure conditions, and the location where gas is absorbed and exothermicly reacted to the inorganic salt, which corresponds to low temperature and low pressure conditions. The present invention relates to a chemical heat pump that is characterized by moving and sequentially circulating an inorganic salt between reaction sites.

Traditionally, absorption refrigerators have been used as chemical heat pump type air-conditioning systems that utilize solar heat, in which, for example, gases such as H ₂ O, CH ₃ OH, and NH ₃ are used as refrigerants, and LiBr, LiCl, NaOH, etc. are used as absorbents. An aqueous solution of or a liquid such as H ₂ O is used.

As described above, all absorbents for conventional chemical heat pump type air conditioning systems use liquids because fluidity is required. However, the disadvantages of these liquids are their high vapor pressure and limited operating temperature. In contrast, the absorbent of the present invention is a solid inorganic salt, and is characterized in that its vapor pressure at operating temperatures is extremely low and can be ignored.

In addition, in chemical heat pumps that combine two types of reactions using solid absorbents, there is no known method for circulating solid absorbents between a container in a high temperature, high pressure state and a container in a low temperature, low pressure state. There are metal hydrides as
No. 33588). However, the method of circulating the inorganic salt absorbent between the gas decomposition reactor and the gas absorption reactor and circulating the gas between the high-temperature, high-pressure side container and the low-temperature, low-pressure side container is one of the features of the present invention. It is. Conventionally, chemical heat pumps that combine two types of reactions using inorganic salt absorbents have been considered for application as long-term heat storage or heat storage.
In this method, two types of inorganic salt absorbents were fixedly stored in their respective containers, and the absorption reaction and decomposition reaction were alternately performed.
That is, this method is a long-term intermittent operation, and the drawback of this method is that it cannot be operated continuously.

FIG. 1 shows a basic configuration diagram related to the implementation of the present invention. 1 and 2 are gas decomposition reactors each having the function of generating gas by thermally decomposing an inorganic salt that has already absorbed gas, and separating the generated gas from the decomposed inorganic salt; 1 is a gas decomposition reactor on the high temperature side; Of, 2
is the gas decomposition reactor on the low temperature side. That is, 1
The gas decomposition reactor 2 uses high-temperature thermal energy such as solar heat or waste heat as the heat source for thermal decomposition, whereas the gas decomposition reactor 2 is different in that low-temperature thermal energy such as indoor air to be cooled is used as the heat source for thermal decomposition. be. 3 and 4 are gas absorption reactors that have the function of reacting the carried inorganic salt with gas and sending out the gas as an absorbed inorganic salt; 3 is the gas absorption reactor on the high temperature side, and 4 is the gas absorption reaction on the low temperature side. It is a vessel. That is, in the gas absorption reactor 3, high-temperature thermal energy generated when inorganic salt absorbs gas is used for heating or hot water supply, whereas in gas absorption reactor 4, low-temperature thermal energy generated when inorganic salt absorbs gas is used. They differ in that they are disposed of in natural cold bodies such as outside air or underground water. Next, between the gas decomposition reactor 1 and the gas absorption reactor 3, the inorganic salt is transferred from the gas decomposition reactor 1 to the gas absorption reactor 3 by the inorganic salt transfer device 5, and the inorganic salt transfer device 6 which has absorbed the gas They are interconnected by a connecting pipe 7 for transferring the inorganic salt that has absorbed gas from the gas absorption reactor 3 to the gas decomposition reactor 1. Here, either one of the inorganic salt transfer devices 5 and 6 may utilize natural falling due to gravity.
Similarly, the gas absorption reactor 4 and the gas decomposition reactor 2 move the inorganic salt that has absorbed the gas from the gas absorption reactor 4 to the gas decomposition reactor 2 by the inorganic salt transfer device 8 that has absorbed the gas, They are interconnected by a connecting pipe 10 for transferring the inorganic salt from the gas decomposition reactor 2 to the gas absorption reactor 4 by the inorganic salt transfer device 9. Here, the inorganic salt transfer device 8,
It is also possible for any one of the devices 9 to utilize natural falling due to gravity. Next, the gas decomposition reactor 1 and the gas absorption reactor 4 are basically connected by a connecting pipe 11 that transports gas from the gas decomposition reactor 1 to the gas absorption reactor 4. However, in order to efficiently transport gas, a carrier gas (which does not react with gas) is used, and as shown in FIG.
The gas cracking reactor 1 and the gas absorption reactor 4 are connected by a pair of connecting pipes 11, which are a connecting pipe for transporting carrier gas containing gas to the gas absorption reactor 4 and a connecting pipe for returning the carrier gas from the gas absorption reactor 4 to the gas decomposition reactor 1. are connected. Here, a gas transport device 12 is used to circulate the carrier gas between the gas decomposition reactor 1 and the gas absorption reactor 4, and this gas transport device 12 is attached to either one of the pair of connecting pipes 11. . Similarly, the gas absorption reactor 3 and the gas decomposition reactor 2 basically refer to the gas decomposition reactor 2 to the gas decomposition reactor 3.
They are connected by a connecting pipe 13 that transports gas to. However, in order to transport gas efficiently, a carrier gas (which does not react with gas) is used.
As shown in FIG. 1, there is a connecting pipe 13 for transporting a carrier gas containing gas from the gas decomposition reactor 2 to the gas absorption reactor 3, and a connection pipe 13 for transporting the carrier gas containing gas from the gas absorption reactor 3 to the gas decomposition reactor 2. The gas absorption reactor 3 and the gas decomposition reactor 2 are connected by a pair of connecting pipes 13. Here, a gas transport device 14 is used to circulate the carrier gas between the gas absorption reactor 3 and the gas decomposition reactor 2.
is attached to one of the pair of connecting pipes 13. Next, 15 is a heat collector, which has the function of collecting natural thermal energy such as solar heat, waste heat from factories, homes, etc., and serves as a heat supply source to the gas decomposition reactor 1. . 1
6 is a heat exchanger between the gas decomposition reactor 1 and the heat collector 15; 17 is a heat exchanger for utilizing the thermal energy obtained in the gas absorption reactor 3 for heating and hot water supply;
18 is a heat exchanger between the gas absorption reactor 4 and a naturally cold body such as outside air or ground water; 19 is a heat exchanger between the gas decomposition reactor 2 and the indoor air to be cooled (however, if cooling is not required, underground water or outside air) It is a heat exchanger with

Next, the principle of operation of the apparatus of the present invention will be explained. The apparatus of the present invention uses a combination of the following two types of reversible reactions.

Here, M・X(s) and N・X(s) are inorganic salts that have absorbed gas, and M(s) and N(s)
is an inorganic salt and X(g) is a gas. The same gas X(g) is always used in the above two types of reversible reactions, but the types of inorganic salts are different between M(s) and N(s).

Therefore, the respective reaction temperatures are different. Here, the reaction temperature of reversible reaction I is higher than that of the reversible reaction. In other words, is the reaction on the high temperature side, and is the reaction on the low temperature side.

The operating operation of the apparatus of the present invention consists of a series of cycles of process A (high temperature gas decomposition) → process B (high temperature gas absorption) → process C (low temperature gas decomposition) → process D (low temperature gas absorption).

In process A, MX(s) transported to the gas decomposition reactor 1 on the high temperature side is supplied with thermal energy from the heat collector 15 and decomposes to generate high temperature gas X(g). The generated high temperature gas X(g) is transported to the gas absorption reactor 4 on the low temperature side through a connecting pipe 11 that circulates carrier gas. At the same time, X(g)
The inorganic salt M(s) on the high temperature side after decomposing part or all of is sent into the gas absorption reactor 3 on the high temperature side through the connecting pipe 7 by the operation of the inorganic salt transfer device 5.

In process B, the inorganic salt N(s) transported to the gas absorption reactor 4 on the low temperature side (through the connecting pipe 10 from the gas decomposition reactor 2 on the low temperature side) and the high temperature gas X
(g) (passed through the connecting pipe 11 from the gas decomposition reactor 1) undergoes an oxidation reaction. That is, this is a process in which N(s) absorbs X(g) in the gas absorption reactor 4. The heat released at this time is disposed of through the heat exchanger 18 into a natural cooling body such as underground water or outside air. The inorganic salt N・X(s) that absorbed the gas is connected to the connecting pipe 10.
Through the operation of the inorganic salt transfer device 8, the gas is absorbed and sent to the gas decomposition reactor 2.

In process C, N. ) is generated by decomposition. The generated low-temperature gas X(g) is sent to the gas absorption reactor 3 on the high temperature side through the connecting pipe 13 through which carrier gas is circulated by the operation of the gas transport device 14. At the same time, the inorganic salt N(s) on the low temperature side after part or all of X(g) has been decomposed in the gas decomposition reactor 2 is transferred to the gas on the low temperature side through the connecting pipe 10 by the operation of the inorganic salt transfer device 9. Absorption reactor 4
sent to.

In process D, the inorganic salt M(s) on the high temperature side that has been transported to the gas absorption reactor 3 on the high temperature side is transported from the gas decomposition reactor 2 on the low temperature side to the gas absorption reactor 3 on the high temperature side through the connecting pipe 13. It absorbs and reacts with the low-temperature gas X(g), forming an inorganic salt M. The high temperature thermal energy generated in this absorption reaction is used for space heating and hot water supply through the heat exchanger 17. The generated M・X(s) is transferred to an inorganic salt transfer device 6 that has absorbed gas.
, the gas is sent through the connecting pipe 7 to the gas decomposition reactor 1 on the high temperature side again.

By continuously repeating the above steps A→B→C→D, the thermal energy absorption within the gas decomposition reactor 2 on the low temperature side that occurs particularly in step C can be used for cooling, and also in step D. Thermal energy release occurring within the gas absorption reactor 3 on the high temperature side can be used for space heating or hot water supply. Moreover, they can be performed continuously.

This will be explained below with specific examples.

Prepare commercially available nickel chloride (NiCl ₂ ) as the inorganic salt on the high temperature side, commercially available calcium chloride (CaCl ₂ ) as the inorganic salt on the low temperature side, and commercially available ammonia gas (NH ₃ ) as the common gas.
We selected a combination of the following two types of reversible reactions.

NiCl ₂・2NH ₃ - NH ₃ system reversible reaction and
Figure 2 shows the equilibrium vapor pressure-temperature curves for each reversible reaction in the CaCl ₂ 4NH ₃ -NH ₃ system. One atmosphere was selected as the equilibrium vapor pressure of ammonia gas on the high temperature side. The equilibrium temperature in the reversible reaction at this time is
168℃, and the equilibrium temperature in a reversible reaction is 31
It is ℃. On the other hand, 0.14 atm was chosen as the equilibrium vapor pressure of ammonia gas on the low temperature side. The equilibrium temperature in the reversible reaction at this time is 122°C, and the equilibrium temperature in the reversible reaction is 0°C.

The decomposition reaction temperature of NiCl ₂ .6NH ₃ (s) in the gas decomposition reactor 1 on the high temperature side in process A (gas decomposition process) was selected to be 170°C. At this time, the partial pressure of the ammonia vapor generated is 1.05 atm. Generally, the operating point A of the decomposition reaction on the high temperature side should be higher than the equilibrium temperature of 168° C. and the equilibrium vapor pressure of 1 atmosphere. The thermal energy to be supplied from the heat collector 15 required for the decomposition reaction on the high temperature side of process A is 59.1 kcal/mole.

In process B (gas absorption process), the reaction temperature at which CaCl ₂ .4NH ₃ in the gas absorption reactor 4 on the low temperature side absorbs high temperature ammonia gas was selected to be 30°C. The partial pressure of ammonia vapor at this time is 0.9 atmospheres.
Generally, the operating point B of the absorption reaction on the low temperature side should be lower than the equilibrium temperature of 31° C. and the equilibrium vapor pressure of 1 atmosphere. In process B, the thermal energy required to be pumped out through the heat exchanger 43 for CaCl ₂ 4NH ₃ (s) to absorb ammonia gas and form CaCl ₂ 8NH ₄ (s) is 40.7 kcal/ It's a mole.

In process C (gas decomposition process), CaCl ₂ 8NH ₃ (s) sent to the gas decomposition reactor 4 on the low temperature side has an equilibrium vapor pressure of 0.14 atm and an equilibrium temperature of 0°C, which are set in the gas decomposition reactor 4. Operating point C slightly higher than
(vapor pressure 0.2 atm, temperature 5°C), 4NH ₃ is decomposed and released to become CaCl ₂ 4NH ₄ (s). The amount of heat absorbed by the decomposition reaction at this time is approximately 40.9kcal/
mole, and this thermal energy is supplied through the heat exchanger 19 with the thermal energy in the room to be cooled. The cooling limit temperature is the temperature at the set operating point C.

In _process D (gas absorption process), the absorption reaction _temperature (operating It is necessary to maintain the temperature at point D below the equilibrium temperature of 122°C. That is,
Amount of heat released by absorption reaction: 59.3kcal/mole
It is necessary to quickly take out the gas through the heat exchanger 17 to the outside of the gas absorption reactor 3 on the high temperature side.
This released thermal energy is used for heating or hot water supply. However, their reaching limit temperature is the temperature of the set operating point D.

In addition, as an embodiment of the present invention, as shown in FIG. It has been found that when the carrier gas (nitrogen gas) is circulated at high speed, the higher the circulation speed, the closer the operating points A and B are to their respective equilibrium temperatures. Similarly, if carrier gas (nitrogen gas) is circulated at high speed between the gas decomposition reactor 2 on the low temperature side and the gas absorption reactor 3 on the high temperature side using a pair of connecting pipes 13 and the gas transport device 14, It has been found that the higher the circulation rate, the closer the operating points C and D are to their respective equilibrium temperatures.

In this way, the continuous process A→B→C→D combines the reversible reaction on the high temperature side of the NiCl ₂ 2NH ₃ -NH ₃ system and the reversible reaction on the low temperature side of the CaCl ₂ 4NH ₃ -NH ₃ system. By repeating the process, the ammonia vapor becomes almost 1
It was possible to perform continuous cooling and heating or hot water supply at low pressures below atmospheric pressure.

As explained above, the present invention enables continuous operation (for example, storing solar heat during the day while simultaneously providing heating and cooling), which has not been possible with conventional fixed chemical heat pumps that use solid absorbents. This has made it possible to reduce the size and weight of continuous chemical heat pumps (e.g. H ₂ O-
However, in the _present invention, the operating vapor pressure including the carrier gas is at most several atmospheres, which is almost It can be used under normal pressure, and the vapor pressure of the absorbent is almost negligible, providing excellent effects.

[Brief explanation of the drawing]

Fig. 1 is an explanatory circuit diagram of the chemical heat pump type air-conditioning/hot-water supply system of the present invention, and Fig. ₂ is a
It is an equilibrium vapor pressure-temperature characteristic diagram of the 2NH ₄ -NH ₃ system and the CaCl _{2.4NH 4} -NH ₃ system. 1, 2... Gas decomposition reactor, 3, 4... Gas absorption reactor, 5, 6, 8, 9... Inorganic salt transfer device,
12, 14... Gas transport device.

Claims (1)

[Claims] 1 The absorption reaction of gas into an inorganic salt (exothermic) and the decomposition reaction of gas from an inorganic salt (endothermic) are reversible, and two types of reversible reactions using the same gas but at different reaction temperatures are performed. A chemical heat pump is installed, and a gas absorption reactor on the high reaction temperature side, a gas decomposition reactor, a device for moving inorganic salts,
A device for moving the inorganic salt that has absorbed gas, a heat collector, a gas absorption reactor on the low reaction temperature side, a gas decomposition reactor, a device for moving the inorganic salt, a device for moving the inorganic salt that has absorbed gas. A connecting pipe is provided to circulate the inorganic salt on the high temperature side between the gas absorption reactor on the high temperature side and the gas decomposition reactor on the high temperature side by the inorganic salt transfer device on the low temperature side. A connecting pipe is provided to circulate the inorganic salt on the low temperature side between the gas absorber on the low temperature side and the gas decomposer on the low temperature side, and the high temperature and high pressure gas generated in the gas decomposition reactor on the high temperature side is transferred to the low temperature side. A connecting pipe is provided to transport the low temperature and low pressure gas generated in the gas decomposition reactor on the low temperature side to the gas absorption reactor on the high temperature side. A chemical heat pump type air-conditioning/heating/water supply system equipped with a connecting pipe that circulates a heat medium between the gas decomposition reactor and the gas decomposition reactor.