JPH02208429A - Cold heat accumulation system - Google Patents

Abstract

PURPOSE:To improve a heat accumulation efficiency and further enable a large amount of heat to be accumulated by a method wherein a gas clathrate producing part of a cold heat accumulation tank of a cold heat accumulation system is arranged in the middle part of a cold heat accumulation cycle system and connected to a storing part having a pressure regulating pipe arranged therein. CONSTITUTION:A cold heat accumulation cycle system 1 is provided with a gas clathrate producing part 6 constituting a compressor 2, a condenser 3, an expansion valve 4 and a cold heat accumulation tank 5. In a radiation cold cycle 8 is arranged a storing part 13 constituting a circulation pump 9, an opening or closing valve 10, a heat exchanger 11 for heating exchanging with a load, an opening or closing valve 12, a gas clathrate producing part 6 and a cold heat accumulating tank 5. The gas clathrate producing part 6 and the storing part 13 are connected by a gas clathrate transmitting pipe 14. Some guest agents having a high specific gravity are accumulated at the lowest layer in the gas clathrate producing part, and some host agents are accumulated at the upper layer of the guest agent in a shallow water depth, resulting in that a liquid pressure of the host agents is low and the guest agents may easily evaporate. Accordingly, a cold heat accumulating efficiency can be improved and the gas clathrate is carried to the storing part and it is possible to make a large amount of capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cold heat storage system, and more particularly to a cold heat storage system that uses gas clathrate produced by the reaction of a host agent and a guest agent as a cold heat storage agent.

[Conventional technology]

Recently, heat pump type cooling devices have become popular, and are now being used not only in offices but also in homes and trains. Extreme peaks in electricity demand can occur in midsummer. Therefore, from this point of view, there is a need for a cold storage heat system that stores a cold source and uses it when it is desired to use it.

Although there are ice cold storage thermal systems that use latent heat as a cold storage device, cold storage thermal systems that use gas clathrates, which undergo a phase change at a higher temperature than ice and have a large cold storage capacity, are attracting attention. This gas clathrate contains hydrocarbons such as methane, ethane, propane, R11, R12, It has a specific crystal structure formed by incorporating a gaseous guest agent of a fluorocarbon refrigerant such as R21.

As a cold storage heat system using gas clathrate, for example, one disclosed in Japanese Patent Application Laid-Open No. 125550/1983 is known (as 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, and 25 is a rectifier.By connecting these with piping in the order described, the cold storage cycle system 26
is configured.

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

The cold storage tank 24 has a structure resistant to reduced pressure, and contains water as a host agent and fluorocarbon as a guest agent.

During cold storage heat operation, the circulation pump 27 is stopped to stop the operation of the cold release cycle system 32, and the compressor 21 is started to operate the cold storage cycle system 26.

In this operating state, fluorocarbon 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 fluorocarbon gas enters the condenser 22, where it condenses to become a fluorocarbon liquid and enters the expansion valve 23.
Here, it expands adiabatically and enters the cold storage tank 24. Then, in the cold storage tank 24, the fluorocarbon (guest agent) is evaporated, and the evaporated fluorocarbon reacts with water (host agent) to generate gas clathrate.

During cooling heat radiation operation, the compressor 21 is stopped to stop the operation of the cold storage cycle system 26, and the circulation pump 27 is started to operate the cooling cycle 32. The cooled fluorocarbon liquid in the cold storage tank 24 is taken out by the circulation pump 27 via the filter 31 and sent to the user-side heat exchanger 28, where it is left to cool. The cooled fluorocarbon liquid is ejected from the spray nozzle 30 into the cold storage tank 24 through the expansion device 29. In the cool storage tank 24, the gas clathrate absorbs the heat of the circulating fluorocarbon liquid, decomposes it, and cools the fluorocarbon liquid.

[Problem to be solved by the invention]

In the conventional cold storage heat system, inside the cold storage tank 24,
It contains water as a host agent and fluorocarbon as a guest agent.

Here, there are various guest agents, but for example, the fluorocarbon-based refrigerant R11 (lichlorofluoromethane) is poorly water-soluble and has a low evaporation pressure (approximately 0.62 kg/kg at 10°C).
Since it has the property of C11l abs), it forms an approximately 8° CO gas clathrate (ice-like substance) with water as a host agent, making it suitable as a cold storage agent. When this R11 is used as a guest agent, R11 is in a liquid state in the cold storage tank 24.
In order to react with the host agent water by evaporating R11 to generate gas clathrate, the pressure applied to R11 in a liquid state in the cold storage tank 24 must be reduced (and this R1
It is necessary to make it easier to evaporate 1.

However, in the cold storage tank 24, the specific gravity of liquid R11 (1
Since R11 (1.51 g/cuff at 0°C) is larger than the specific gravity of water, R11 accumulates in the bottom layer, gas clathrate accumulates in the layer above it, and water also accumulates in the top layer above this gas clathrate. has accumulated.

Therefore, the water pressure of the water accumulated in the uppermost layer is applied to R11 in the lowermost layer in the cold storage tank 24, and the pressure applied to R11 in this state increases, making it difficult for R11 to evaporate and reducing the gas clathrate. There is a problem in that the generation efficiency decreases and, as a result, the cold storage efficiency deteriorates.

Note that by reducing the depth of the cold storage tank 24 and making the water stored as a host agent shallower, the pressure of the water applied to R11 will also be lower, R11 will be more likely to evaporate, and the gas clathrate will be reduced. Although the generation efficiency can be improved, since the amount of water as a host agent stored in the cold storage tank 24 is small, the amount of gas clathrate generated is small (only a small volume of cold can be stored. In order to store cold, the floor area of the cold storage tank 24 must be increased, which is undesirable and takes up unnecessary space.

In addition, in conventional cold storage heat systems, the structure of the cold storage tank 24 is resistant to reduced pressure, but this prevents outside air from entering into the cold storage tank 24 when gas clathrate is generated. Although the pressure in the R1 tank in the tank 24 can be maintained at a low level, if the capacity of the cold storage tank 24 is increased, a large-scale pressure reduction resistant structure is required, which becomes expensive.

As mentioned above, the case where R11 with a low evaporation pressure is used as the fluorocarbon refrigerant has been described. However, when using a fluorocarbon refrigerant with an evaporation pressure higher than atmospheric pressure, the fluorocarbon is removed from the cold storage tank 24. The structure of the cold storage tank 24 needs to be pressure-resistant so that the system refrigerant does not leak, but if the capacity of the cold storage tank 24 is increased, a large-scale pressure-resistant structure is required, which becomes expensive.

The present invention was made to solve the above-mentioned problems, and its purpose is to improve gas clathrate generation efficiency and to enable large-capacity cold storage even if the floor area of the cold storage tank is small. Moreover, it is an object of the present invention to provide a cold storage heat system that does not require a large-scale pressure-resistant structure or depressurization-resistant structure for a large-capacity cold storage tank.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a cold storage tank.

It consists of a cold storage cycle system that has a compressor, a condenser, and an expansion valve, and a cold release cycle system that is connected to this cold storage cycle system via the cold storage tank. The guest agent in the cold storage tank is circulated through the cold storage cycle system, and by evaporating the guest agent in the cold storage tank, the evaporated guest agent and host agent react to generate gas clathrate. In a cold storage heat system that uses this gas clathrate as a cold storage heat agent in a cooling cycle system, the cold storage tank includes a gas clathrate generation section that generates the gas clathrate, and an internal gas area that stores the gas clathrate. The gas clathrate generating section is placed in the middle of the cold storage cycle system, and the storage part is placed in the middle of the cold release cycle system. The clathrate generating section and the storage section are connected through a gas clathrate transfer pipe, and a seal valve or a positive displacement pump is interposed in the middle of the gas clathrate transfer pipe.

[For production]

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 generating section of the cold storage tank. The guest agent evaporates within the gas clathrate generating section, the host agent and guest agent in the cold storage tank are cooled by the heat of evaporation, and the evaporated guest agent and host agent react to generate gas clathrate. When this gas clathrate is generated, the gas area of the gas clathrate generating section and the gas area of the storage section are shut off by closing the seal valve or stopping the positive displacement pump. At this time, the gas region of the gas clathrate generating section is at a predetermined pressure. On the other hand, the gas region of the storage section is maintained at a pressure close to atmospheric pressure by being supplied with a suitable gas such as nitrogen through a pressure regulating pipe, or by removing the gas.

When gas clathrate accumulates in the gas clathrate generation section, by opening the seal valve or operating the positive displacement pump, the gas clathrate is removed from the gas clathrate generation section.
Gas clathrate is delivered to storage via a gas clathrate transfer tube.

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

Then, in the storage section of the cold storage tank, the gas clathrate as a cold storage agent and the guest agent circulating in the cooling cycle system undergo heat exchange, the gas clathrate is decomposed, and the guest agent is cooled. This cooled guest agent circulates through the cooling cycle system to cool the load.

〔Example〕

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

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

In the figure, 1 is a cold storage cycle system, and a compressor 2. Condenser 3. Expansion valve 4. Gas clathrate generating units 6 constituting the cold storage tank 5 are arranged in order. Cold storage tank 5
The gas clathrate generating section 6 has a small floor area, and contains water as a host agent and a fluorocarbon refrigerant R11 ( ) IJ chlorofluoromethane as a guest agent. In addition, in the Taraslate generation section 6,
A stirrer 7 is provided.

8 is a cooling cycle system, in the middle of which is a circulation pump 9.
Open/close valve 10. Heat exchanger 11 that exchanges heat with the load. Open/close valve 12. Gas clathrate generation section 6 of cold storage tank 5.
Storage units 13 forming the cold storage tank 5 are arranged in order.

A filter 13A is disposed within the storage section 13, and R11 flows from the filter 13A to the circulation pump 9. Further, the storage section 13 is provided with a purge gas supply pipe 13B. The gas clathrate generating section 6 and the storage section 13 are connected by a gas clathrate transfer pipe 14, and one end side of the gas clathrate transfer pipe 14 opens into the thallus slate generating section 6 at a predetermined height. A seal valve 14B, such as a rotary valve, is interposed 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 15 is connected in the middle of this bypass passage 15.
A is interposed.

Further, a pipe 16 is connected to the upper side of the storage section 13 and to the middle of the circulation pump 9 and the on-off valve 10 of the cooling cycle system 8 .

In addition, in the figure, 17 is a liquid level switch that detects the liquid level in the gas clathrate generating section 6.

Next, the operation of this embodiment will be explained.

During cold storage heat operation, the on-off valves 10 and 12 are closed, the switching valve 15A is opened, the circulation pump 9 is started, and the cooling cycle system is activated so that the heat exchanger 11 is not activated, as shown by the solid arrow. The cold storage cycle system 1 is operated by partially using the compressor 8 and starting the compressor 2. In this operating state, gas R11 is taken out from the gas region of the gas clathrate generating section 6 of the cold storage tank 5 and compressed by the compressor 2. Compressed R11
enters the condenser 3, where it condenses and becomes a fluorocarbon liquid, enters the expansion valve 4, where it undergoes adiabatic expansion and enters the gas clathrate generation section 6.

When gas clathrate is generated, when the amount of gas clathrate generated is small, the liquid level 6A of the gas clathrate generating section 6 is at a lowered position, and the position of this liquid level 6A is detected by the liquid level switch 17 and the seal valve is activated. 14B is closed, cutting off the gas area of the gas clathrate generating section 6 and the gas area of the storage section 13.

At this time, the pressure in the gas region of the gas clathrate generating section 6 is low. On the other hand, the gas region of the storage section 13 is maintained at a pressure close to atmospheric pressure by supplying nitrogen gas from the purge gas supply pipe 13B.

Then, R11 is evaporated in the gas clathrate generation unit 6, and the water and R11 in the clathrate generation unit 6 are cooled by the heat of evaporation, and the evaporated R11 and water as a host agent react to form a gas. A class rate is generated. By stirring the inside of the gas clathrate generating section 6 with the stirrer 7, the contact area between water and R11 is increased, and the gas clathrate generation efficiency is increased.

The gas clathrate generated in the gas clathrate generation unit 6 of the cold storage tank 5 overflows from the top 14A of the gas clathrate transfer pipe 14 together with R11 in a liquid state and water into the gas clathrate transfer pipe 14. It spills and is carried to the storage section 13.

In the storage tank 13, R11 in a liquid state with the highest specific gravity accumulates in the lowest layer A, sherbet-like gas clathrate accumulates in a layer B above this R11, and further in a layer C above this gas clathrate. Water has accumulated. From the storage section 13, R11 in a liquid state located in the lowest layer A is conveyed to the circulation pump 9 via a filter 13A, and water located in the uppermost layer C is conveyed to the circulation pump 9 through a filter 13C. and water are transported to the gas clathrate generation section 6, where gas clathrate is generated. In this way, in the storage section 13, the liquid R11 and water are separated from the gas clathrate, so the amount of liquid R11 and water decreases, and the amount of gas clathrate stored increases.

When gas clathrate is generated in the gas clathrate generation unit 6, the liquid level 6A of the gas clathrate generation unit 6 rises, and the amount of gas clathrate generated exceeds a predetermined amount, the position of this liquid level 6A is changed to the liquid level. The switch 17 detects this and the seal valve 14B opens.

As a result, the gas clathrate is sent from the gas clathrate generation section 6 to the storage section 13 via the gas clathrate transfer pipe 14.

On the other hand, during cooling heat radiation operation, the seal valve 14B is opened,
Thereby, preparations are made for R11 to circulate through the cooling cycle system 8. The compressor 2 is stopped, the operation of the regenerator cycle system 1 is stopped, the opening/closing pulp 10° 12 is opened, the switching pulp 15A is closed, the circulation pump 9 is started, and the valve is released as shown by the dotted arrow. The cold cycle 8 is operated.

The cooled liquid R11 in the storage section 13 is taken out by the Wi-ring pump 9 via the filter 13A and sent to the heat exchanger 11, where it is allowed to cool and undergo heat exchange with the load.

R11 in a liquid state after being left to cool returns to the gas clathrate generation section 6 and further flows to the storage section 13.

In the storage section 13, gas clathrate as a cold storage agent,
Heat is exchanged with R11 in a liquid state circulating through the cooling cycle system, the gas clathrate is decomposed, and R11 in a liquid state is cooled.

According to the above configuration, in the gas clathrate generating section 6, R11 as a guest agent with a high specific gravity is in the lowermost layer, and water as a host agent accumulates in the upper layer of this R11 at a shallow depth, so that it acts on R11. The pressure of the water is small, so R11 evaporates easily, improving the gas clathrate production efficiency and improving the cold storage efficiency.

Furthermore, since the gas clathrate generated in the gas clathrate generation section 6 is transported to the storage section 13, the gas clathrate generation section 6 always has a space for generating gas clathrate, and the gas clathrate generation section 6 Even if the floor area of the storage unit 13 is small, a large amount of gas clathrate can be stored in the storage section 13 without being limited by the generation of gas clathrate, and therefore the cold storage capacity can be increased.

In short, even if the floor area of the gas clathrate generation unit 60 is small, it is possible to improve gas clathrate generation efficiency and to enable large-capacity cold storage.

Furthermore, when gas clathrate is generated, the seal valve 14B
By closing the gas area of the gas clathrate generation unit 6 and the gas area of the storage unit 13 using the seal valve 14B, the gas area within the gas clathrate generation unit 6 can be maintained at a low pressure. , while purge gas supply pipe 1
By supplying nitrogen gas from 3B to the gas region inside the storage section I3, the pressure of the gas region inside the storage section 13 can be maintained at a pressure near atmospheric pressure, and therefore the structure of the storage section 13 can be changed to This has the effect of eliminating the need for a reduced pressure resistant structure.

In this example, R1 is used as the fluorocarbon refrigerant.
Although the explanation has been given using R11, it is not limited to R11. For example, a mixture of fluorocarbon refrigerants R11 and R114 (1,2 dichloro-1,1,2,2 tetrafluoroethane) or a fluorocarbon refrigerant R21 (dichloromonofluoromethane) can also be used. Here, the evaporation pressure of R114 is 10°C and is 3kg/c+fi absXR2
The evaporation pressure of No. 1 is 1.08 kg/CIaabs at 10°C. Furthermore, a mixture of R11 and R12 (dichlorodifluoromethane) may be used as the fluorocarbon refrigerant.

Furthermore, in this embodiment, the purge gas supply section 13B is connected to the storage section 13, but if a high-pressure fluorocarbon refrigerant is used, the purge gas supply section 13B may be replaced with a gas venting section 13B. It is also possible to connect a pipe and use this degassing pipe to reduce the pressure in the gas region space in the reservoir 13 to a value near atmospheric pressure.

Furthermore, in this embodiment, a seal valve 14B is interposed in the middle of the gas clathrate transfer pipe 14, but a positive displacement pump may be used instead of the seal valve 14B.

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

〔Effect of the invention〕

As described above, according to the cold storage heat system according to the present invention, in the gas clathrate generation section, a guest agent with a high specific gravity is accumulated in the lowest layer, and a host agent is accumulated in the upper layer of this guest agent at a shallow water depth. The liquid pressure of the host agent acting on the guest agent is small, so the guest agent evaporates easily, improving the gas clathrate production efficiency and improving the cold storage efficiency.

In addition, the gas clathrate generated in the gas clathrate generation section is transported to the storage section, so there is always space to generate gas clathrate in the gas clathrate generation section, and the floor area of the gas clathrate generation section is reduced. Even if it's small,
A large amount of gas clathrate can be stored in the storage section without being limited by the generation of gas clathrate, and therefore the cold storage capacity can be increased.

In short, even if the floor area of the gas clathrate generation section is small, the gas clathrate generation efficiency can be improved and a large capacity of cold storage can be achieved.

Furthermore, when gas clathrate is generated, the seal valve is closed or the positive displacement pump is stopped, and the gas area of the gas clathrate generating part and the gas area of the storage part are cut off by the seal valve or the positive displacement pump. The gas region in the clathrate generating section can be maintained at a predetermined pressure, while the gas region in the reservoir can be supplied with purge gas through a pressure regulating pipe or degassed. can be maintained at a pressure close to atmospheric pressure, and therefore, there is an effect that the structure of the storage section does not need to be a pressure-resistant structure or a reduced-pressure resistant structure.

8・・・ 13・ 3B I　4　・ 4B Cooling cycle system ・Storage section.

・Purge gas supply pipe ・Gas clathrate transfer pipe ・Seal valve.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a cold storage heat system according to an embodiment of the present invention. FIG. 2 is a configuration diagram of a conventional cold storage heat system. [Explanation of symbols of main parts] 1... Cold storage cycle system 2... Compressor 3... Condenser 4... Expansion valve 5... Cold storage tank 6... Gas clathrate generation section figure? 03 (Sairi/? @ Katana Toji Diagram q

Claims (1)

[Claims] (1) Consists of a cold storage cycle system having a cold storage tank, a compressor, a condenser, and an expansion valve, and a cold release cycle system connected to this 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 stored, the guest agent in the cold storage tank is circulated through the cold storage cycle system, and the evaporated guest agent and host agent are evaporated in the cold storage tank. In a cold storage heat system that reacts to generate gas clathrate and uses this gas clathrate as a cold heat storage agent in a cooling cycle system, the cold storage tank includes a gas clathrate generation section that generates gas clathrate, and a gas clathrate generating section that generates gas clathrate; The gas clathrate generating section is placed in the middle of the cold storage cycle system, and the storage section is equipped with a pressure regulating pipe that stores the gas clathrate and controls the internal gas area to near atmospheric pressure. A gas clathrate generating section and a storage section are placed in the middle of the system, and the gas clathrate generating part and the storage part are connected through a gas clathrate transfer pipe, and a seal valve or a positive displacement pump is interposed in the middle of the gas clathrate transfer pipe. A cold storage heat system.