JPH0796942B2 - Cold storage system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cold storage heat system, and more particularly, to a cold storage heat system that uses a gas clathrate generated by a reaction between a host agent and a guest agent as the cold storage heat agent.

[Conventional technology]

Recently, heat pump type air conditioners have become widespread, and have spread not only to offices but also to homes and trains. Extreme peaks in power demand can occur in midsummer. From this point of view, therefore, there is a demand for a cold storage heat system that is used when a cold source is stored and used.

There is an ice cold storage system that uses latent heat as a cold storage device, but a cold storage system that uses a gas clathrate that has a large cold storage capacity and undergoes a phase change at a temperature higher than ice is drawing attention. This gas clathrate is a hydrocarbon such as methane, ethane or propane, or R11, R12, or R11, R12, in the voids formed inside the framework of the three-dimensional structure formed by binding the atoms or molecules of the host agent such as water. It has a specific crystal structure formed by incorporating a gaseous guest agent such as a R21 refrigerant.

As a cold storage heat system using a gas clathrate, for example, one shown in JP-A-61-125550 is known (shown in FIG. 2).

In the figure, 21 is a compressor, 22 is a condenser, 23 is an expansion valve, 24
Is a cold storage tank, 25 is a rectifier, and a cold storage cycle system 26 is configured by connecting these with piping in the order described.

27 is a circulation pump, 28 is a heat exchanger on the use side, 29 is a throttle device such as a throttle valve, 30 is a spray nozzle arranged in a gas region in the cold storage tank 24, and 31 is immersed in the liquid in the cold storage tank 24. The cooling cycle system 32 is configured by connecting these with the pipes in the order described in the described filters.

The cold storage tank 24 has a decompression-resistant structure, and inside thereof, water as a host agent and CFCs as a guest agent are contained.

During the cold storage heat operation, the circulation pump 27 is stopped to stop the operation of the cold discharge cycle system 32, and the compressor 21 is started to operate the cold storage cycle system 26. In this operating state, the chlorofluorocarbon gas is taken out from the gas region of the cold storage tank 24 via the rectifier 25 and compressed by the compressor 21. The compressed Freon gas enters the condenser 22, where it is condensed and becomes Freon liquid and enters the expansion valve 23, where it adiabatically expands and enters the cold storage tank 24. Then, in the cold storage tank 24, by evaporating the fluorocarbon (guest agent), the vaporized fluorocarbon reacts with water (host agent) to generate a gas clathrate.

During cold heat operation, the compressor 21 is stopped and the cool storage cycle system
The operation of 26 is stopped, the circulation pump 27 is started, and the cooling cycle 32 is operated. The chlorofluorocarbon liquid cooled in the regenerator 24 is taken out through the filter 31 by the circulation pump 27, sent to the heat exchanger 28 on the use side, and allowed to cool there. The CFC liquid after being cooled is ejected from the spray nozzle 30 into the cold storage tank 24 through the expansion device 29. In the cold storage tank 24, the gas clathrate absorbs the heat of the circulating CFC liquid and decomposes it to cool the CFC liquid.

[Problems to be Solved by the Invention]

In the conventional cold storage system, the cold storage tank 24 contains water as a host agent and CFCs as a guest agent.

Here, there are various guest agents, but for example, the CFC-based refrigerant R11 (trichlorofluoromethane) has the property of being poorly water-soluble and having a low evaporation pressure (about 0.62 kg / cm ² abs at 10 ° C). It is suitable as a cold storage agent by making water as a host agent and gas clathrate (ice-like substance) at about 8 ° C. When this R11 is adopted as the guest agent, in order to generate the gas clathrate by reacting with the water of the host agent by evaporating R11 in the liquid state in the cold storage tank 24, the liquid state in the cold storage tank 24 is generated. It is necessary to lower the pressure applied to R11 in order to facilitate evaporation of this R11.

However, in the cold storage tank 24, the specific gravity of liquid R11 (at 10 ° C
Since 1.51 g / cm ³ ) is larger than the specific gravity of water, R11 accumulates in the bottom layer, gas clathrate accumulates in the layer above it, and water accumulates in the top layer above this gas clathrate. Has become.

Therefore, the lowest layer R11 in the cold storage tank 24, the water pressure of the water accumulated in the uppermost layer is applied, the pressure applied to R11 in this state becomes high, R11 becomes difficult to evaporate, the gas clathrate of There is a problem that the production efficiency is lowered and the cold storage efficiency is deteriorated.

In addition, if the depth of the cold storage tank 24 is made low and the depth of the water contained as the host agent is made shallow, the pressure of the water applied to R11 also becomes low, R11 easily evaporates, and gas clathrate is generated. Although the efficiency can be improved, since the amount of water as a host agent contained in the cold storage tank 24 is small, the amount of gas clathrate produced is small and only a small amount of cold storage can be performed. If a large amount of cold storage is to be obtained, the floor area of the cold storage tank 24 must be widened, which is unpreferable because it requires a lot of space.

Further, in the conventional cold storage heat system, the structure of the cold storage tank 24 is
Although it has a decompression resistant structure, this can prevent the outside air from entering the cold storage tank 24 and maintain the pressure of R11 in the cold storage tank 24 at a low state when the gas clathrate is generated. However, if the cold storage tank 24 has a large capacity, a large-scale decompression resistant structure is inevitably provided, which is expensive.

Then, as described above, the case where R11 having a low evaporation pressure is used as the CFC-based refrigerant has been described, but when a refrigerant having a higher evaporation pressure than the atmospheric pressure is used as the CFC-based refrigerant, the CFC from the cold storage tank 24 is used. It is necessary to make the structure of the cold storage tank 24 a pressure resistant structure so that the system refrigerant does not leak, but if the cold storage tank 24 has a large capacity, a large-scale pressure resistant structure is inevitably applied, which is expensive.

The present invention has been made to solve the above-described problems, and an object thereof is to improve the gas clathrate generation efficiency and to store a large amount of cold energy even if the floor area of the cold energy storage tank is small. Moreover, it is an object of the present invention to provide a cold storage heat system in which a large-scale cold storage tank does not have to be provided with a large-scale pressure resistance structure or pressure reduction resistance structure.

[Means for Solving the Problems]

In order to achieve the above object, the present invention comprises a cold storage cycle system having a cold storage tank, a compressor, a condenser, and an expansion valve, and a cold discharge cycle system connected to the cold storage cycle system via the cold storage tank. The host agent and the guest agent that is difficult to dissolve in the host agent are stored in the cool storage tank, the guest agent in the cool storage tank is circulated in the cool storage cycle system, and the guest agent is evaporated in the cool storage tank. In a cold storage heat system in which a guest agent and a host agent react to generate a gas clathrate, and the gas clathrate is used as a cold heat storage agent in a cooling cycle system, the cold storage tank is a gas class that produces a gas clathrate. The gas clathrate generator is equipped with a rate generator and a storage unit that stores a gas clathrate and also has a pressure adjustment tube that controls the internal gas region to near atmospheric pressure. In addition to arranging in the middle of the icle system, the storage part is arranged in the middle of the cooling cycle system, and the gas clathrate generation part and the storage part are connected via the gas clathrate transfer pipe, and in the middle of the gas clathrate transfer pipe. In addition, a seal valve or a positive displacement pump is interposed.

[Action]

In the present invention, during the cold storage heat operation, the guest agent in the liquid state of the cold storage cycle system enters the gas clathrate generator of the cold storage tank. The guest agent evaporates in the gas clathrate generator, the host agent and the guest agent in the regenerator are cooled by the heat of evaporation, and the evaporated guest agent reacts with the host agent to generate gas clathrate. When the gas clathrate is generated, the gas region of the gas clathrate generation unit and the gas region of the storage unit are shut off by closing the seal valve or stopping the positive displacement pump. At this time, the gas region of the gas clathrate generator is at a predetermined pressure. On the other hand, the gas region of the storage unit is maintained at a pressure close to the atmospheric pressure by supplying an appropriate gas such as nitrogen through the pressure adjusting pipe or by removing the gas.

Then, when the gas clathrate is accumulated in the gas clathrate generator, the seal valve is opened or the positive displacement pump is operated, whereby the gas clathrate generator generates,
The gas clathrate is sent to the storage via the gas clathrate transfer pipe.

On the other hand, during the cooling heat operation, the seal valve is opened or the positive displacement pump is operated, whereby the guest agent is ready to circulate in the cooling cycle system.

Then, in the storage part of the cold storage tank, heat exchange is performed between the gas clathrate as the cold storage agent and the guest agent circulating in the cooling cycle system, the gas clathrate is decomposed, and the guest agent is cooled. This cooled guest agent circulates in the cooling cycle system, and the load is cooled.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a cold heat storage system according to an embodiment of the present invention.

In the figure, reference numeral 1 is a cold storage cycle system, and a compressor 2, a condenser 3, an expansion valve 4, and a gas clathrate generator 6 constituting a cold storage tank 5 are sequentially arranged in the middle thereof. The gas clathrate generator 6 of the cold storage tank 5 has a small floor area, and contains water as a host agent and a CFC-based refrigerant R11 (trichlorofluoromethane) as a guest agent therein. A stirrer 7 is provided in the clathrate generator 6.

8 is a cooling cycle system, in the middle of which a circulation pump 9, an on-off valve 10, a heat exchanger 11 for exchanging heat with a load, an on-off valve
12, a gas clathrate generator 6 of the cold storage tank 5 and a storage 13 of the cold storage tank 5 are arranged in order. A filter 13A is arranged in the storage unit 13, and R11 flows from the filter 13A to the circulation pump 9. The storage unit 13 is provided with a purge gas supply pipe 13B.
The gas clathrate generation unit 6 and the storage unit 13 are connected by a gas clathrate transfer pipe 14, and one end side of the gas clathrate transfer pipe 14 opens in the clathrate generation unit 6 at a predetermined height. A seal valve 14B such as a rotary valve is provided in the middle of the gas clathrate transfer pipe 14.

A bypass passage 15 is connected to the upstream side of the on-off valve 10 and the downstream side of the on-off valve 12 of the cooling cycle system 8, and a switching valve 15A is interposed in the middle of the bypass passage 15.

A pipe 16 is connected to the upper side of the storage unit 13 and to the circulation pump 9 and the opening / closing valve 10 of the cooling cycle system 8.

In the figure, 17 is a liquid level switch for detecting the liquid level in the gas clathrate generator 6.

Next, the operation of this embodiment will be described.

During the cold storage heat operation, the open / close valves 10 and 12 are closed and the switching valve 15A is opened to start the circulation pump 9, and the cooling cycle system is arranged so that the heat exchanger 11 does not act as indicated by the solid arrow. 8 is partially used and the compressor 2 is started to cool the cold storage cycle system 1
To drive. In this operating state, gas R11 is taken out from the gas region of the gas clathrate generator 6 of the cold storage tank 5 and compressed by the compressor 2. Compressed R11 is condenser 3
It enters into the inside, condenses here, becomes a Freon liquid, enters the expansion valve 4, and here adiabatically expands and enters the gas clathrate generator 6.

At the time of gas clathrate generation, when the amount of gas clathrate generated is small, the liquid level 6A of the gas clathrate generator 6 is at a lowered position, and the position of this liquid level 6A is set to the liquid level switch 17
Then, the seal valve 14B is closed and the gas region of the gas clathrate generator 6 and the gas region of the storage unit 13 are shut off. At this time, the gas region of the gas clathrate generator 6 has a low pressure. On the other hand, the gas region of the storage unit 13 is maintained at a pressure close to the atmospheric pressure by supplying the nitrogen gas from the purge gas supply pipe 13B.

Then, R11 is evaporated in the gas clathrate generator 6, and the heat of evaporation causes water and water in the clathrate generator 6 to be generated.
While R11 is cooled, the evaporated R11 reacts with water as a host agent to generate a gas clathrate. By stirring the inside of the gas clathrate generator 6 with the stirrer 7, the contact area between water and R11 is increased, and the gas clathrate generation efficiency is increased.

Then, the gas clathrate generated in the gas clathrate generator 6 of the cold storage tank 5 overflows from the top 14A of the gas clathrate transfer pipe 14 together with the liquid R11 and water into the gas clathrate transfer pipe 14. Spilled, storage
Transported to 13.

In the storage tank 13, R11 in the liquid state having the highest specific gravity is accumulated in the lowermost layer A, a sherbet-like gas clathrate is accumulated in the layer B above this R11, and further in the layer C above this gas clathrate. Water is accumulated. From the storage unit 13, the liquid state R11 located in the lowermost layer A is carried to the circulation pump 9 through the filter 13A, and the water located in the uppermost layer C is carried to the circulation pump 9 through the filter 13C, and the liquid state R11 is carried out. And water are carried to the gas clathrate generator 6, and the gas clathrate is generated. Thus, in the storage unit 13, the liquid R1
Since 1 and water are separated from the gas clathrate, the amount of R11 and water in the liquid state is small, and the storage amount of gas clathrate is large.

When the gas clathrate is generated in the gas clathrate generator 6, the liquid level 6A of the gas clathrate generator 6 rises, and when the amount of gas clathrate generated exceeds a predetermined amount, the position of this liquid level 6A is changed to the liquid level. Seal valve detected by switch 17
14B opens. As a result, the gas clathrate generation unit 6 sends the gas clathrate to the storage unit 13 via the gas clathrate transfer pipe 14.

On the other hand, during the cooling heat operation, the seal valve 14B is opened, whereby R11 is ready to circulate in the cooling cycle system 8. The compressor 2 is stopped to stop the operation of the cold storage cycle system 1, the open / close valves 10 and 12 are opened, the switching valve 15A is closed, and the circulation pump 9 is started to release as shown by a dotted arrow. Run the cold cycle 8. The circulation pump 9 takes out the cooled liquid state R11 in the storage unit 13 through the filter 13A and sends it to the heat exchanger 11, where it is allowed to cool and is heat-exchanged with the load. After being left to cool, R11 in a liquid state returns to the gas clathrate generator 6 and further flows to the storage 13.

In the storage unit 13, heat exchange is performed between the gas clathrate as a regenerator and the liquid state R11 circulating in the cooling cycle system, the gas clathrate is decomposed, and the liquid state R11 is cooled.

According to the above configuration, the gas clathrate generator 6
In addition, R11 as a guest agent with a large specific gravity in its bottom layer
However, since water as a host agent accumulates in the upper layer of this R11 at a shallow water depth, the pressure of the water acting on R11 is small, so that R11 easily evaporates, improving the gas clathrate generation efficiency, and the cold storage efficiency. Can be improved.

In addition, since the gas clathrate generation unit 6 carries the gas clathrate to the storage unit 13, the gas clathrate generation unit 6 always has a space for generating the gas clathrate. Even if the floor area of is small, the generation of gas clathrate is not limited, and a large amount of gas clathrate can be stored in the storage unit 13,
Therefore, the cold storage capacity can be increased.

In short, even if the floor area of the gas clathrate generator 6 is small, it is possible to improve the gas clathrate generation efficiency and enable large-capacity cold storage.

Further, at the time of gas clathrate generation, the seal valve 14B is closed, and the seal valve 14B shuts off the gas region of the gas clathrate generation unit 6 and the gas region of the storage unit 13. The region can be maintained at a low pressure, while the nitrogen gas is supplied from the purge gas supply pipe 13B to the gas region inside the storage unit 13, so that the pressure in the gas region inside the storage unit 13 is close to the atmospheric pressure. Since the pressure can be maintained, the structure of the storage unit 13 does not need to be a pressure reduction resistant structure.

In this embodiment, R11-based refrigerant is R11.
However, the present invention is not limited to R11. For example, fluorocarbon refrigerants R11 and R114 (1,2 dichloro-1,1,2,2
A mixture of tetrafluoroethane) and a fluorocarbon refrigerant R2
It is also possible to use 1 (dichloromonofluoromethane). Here, the evaporation pressure of R114 is 1.3 kg / cm ² ab at 10 ° C.
The evaporation pressure of s and R21 is 1.08 kg / cm ² abs at 10 ° C. Further, a mixture of R11 and R12 (dichlorodifluoromethane) may be used as the chlorofluorocarbon refrigerant.

Further, in the present embodiment, the purge gas supply unit 13B is connected to the storage unit 13. However, when a high pressure refrigerant is used as the fluorocarbon refrigerant, the purge gas supply unit 13B is used.
Instead of this, a gas vent pipe may be connected and the gas vent space in the storage unit 13 may be decompressed by this gas vent pipe to a value near atmospheric pressure.

Further, in this embodiment, the gas clathrate transfer pipe is used.
A seal valve 14B is provided in the middle of 14,
A positive displacement pump can be used instead of the seal valve 14B.

Further, in this embodiment, nitrogen gas is used as the purge gas, but the purge gas is not limited to this.

〔The invention's effect〕

As described above, according to the cold storage heat system of the present invention, in the gas clathrate generating part, the guest agent having a large specific gravity in the lowermost layer, the host agent is accumulated in the upper layer of this guest agent at a shallow water depth, Since the liquid pressure of the host agent acting on the guest agent is small, the guest agent is easily evaporated, the efficiency of gas clathrate generation can be improved, and the cold storage efficiency can be improved.

Moreover, since the gas clathrate generated by the gas clathrate generator is carried to the storage unit, the gas clathrate generator always has a space for generating the gas clathrate, and the floor area of the gas clathrate generator is small. Small,
A large amount of gas clathrate can be stored in the storage unit without being restricted by the generation of gas clathrate, and thus the cold storage capacity can be increased.

In short, even if the floor area of the gas clathrate generator is small, the gas clathrate can be efficiently generated and a large amount of cold can be stored.

Further, when the gas clathrate is generated, the seal valve is closed or the positive displacement pump is stopped, and the gas region of the gas clathrate generation unit and the gas region of the storage unit are shut off by the seal valve or the positive displacement pump. The gas area in the clathrate generator can be maintained at a predetermined pressure, while the gas area in the storage section can be supplied by supplying a purge gas or degassing the gas area in the storage section. The pressure can be maintained at a pressure close to the atmospheric pressure, and therefore, there is an effect that it is not necessary to make the structure of the storage section a pressure resistant or pressure reducing resistant structure.

[Explanation of symbols of main parts]

 1 ... Cool storage cycle system 2 ... Compressor 3 ... Condenser 4 ... Expansion valve 5 ... Cool storage tank 6 ... Gas clathrate generator 8 ... Cooling cycle system 13 ... Storage unit 13B ... Purge gas Supply pipe 14 …… Gas clathrate transfer pipe 14B …… Seal valve.

Claims (1)

[Claims] 1. A cold storage cycle system having a cold storage tank, a compressor, a condenser, and an expansion valve, and a cold discharge cycle system connected to the cold storage cycle system via the cold storage tank. A host agent and a guest agent that is difficult to dissolve in the host agent are housed, the guest agent in the cold storage tank is circulated in the cold storage cycle system, and the guest agent is evaporated in the cold storage tank so that the evaporated guest agent and the host agent are separated from each other. In the cold storage heat system that reacts to generate a gas clathrate and uses this gas clathrate as a cold storage heat agent of a cooling cycle system, the cold storage tank includes a gas clathrate generator that generates a gas clathrate, and a gas clathrate. A gas clathrate generator is provided in the middle of the cold storage cycle system, with a storage unit provided with a pressure adjusting pipe that stores the rate and controls the internal gas region near atmospheric pressure. In both cases, the storage part is arranged in the middle of the cooling cycle system, the gas clathrate generation part and the storage part are connected via a gas clathrate transfer pipe, and a seal valve or positive displacement type is provided in the middle of the gas clathrate transfer pipe. A cold storage heat system characterized by having a pump interposed.