JPH0743039A - Micro wave type cooling method and its device - Google Patents

Abstract

PURPOSE:To provide a small sized cooling system of easy maintenance, which produces no substances that are harmful to humans, other living organisms, and their environments. CONSTITUTION:Water soluble refrigerant liquid is guided in a micro-tube 3 made of uniform film through which only gas can be permeated. A space 3A around an outside part of the tube 3 is maintained at a reduced pressure, refrigerant gas in the tube 3 is deaerated and separated through the uniform film and either water or water solution left in the tube 3 is cooled under utilization of evaporating latent heat of the refrigerant gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling method and apparatus using a microtube composed of a homogeneous membrane that is permeable to only gas.

[0002]

2. Description of the Related Art Conventionally, as a cooling method for obtaining cold water for air conditioning, there are a refrigerating apparatus which constitutes a refrigerating cycle by using Freon gas, an absorption refrigerating apparatus which uses a lithium promide, and the like.

[0003]

However, the CFC used in the CFC gas refrigerating device is a cause of destroying the ozone layer that protects the ultraviolet rays surrounding the earth, and is destined to be totally prohibited in the near future. It is also possible to use an ammonia refrigerant instead of CFC gas, but the gas refrigerant cycle is a compressor, oil separator, condenser, heat exchanger, liquid receiver, expansion valve, evaporator (heat exchanger), Since there are devices such as a liquid separator, the volume is large and the contact area is large.
Further, the material is made of iron, and there is a disadvantage that the weight becomes excessive. On the other hand, in an absorption chiller, it is impossible to dispose of lithium promide carelessly from the standpoint of environmental pollution, and disposal to the ground or sewage is a pollution. Further, the absorption type is disadvantageous in that it requires a regenerator, a condenser, an evaporator, an absorber, a solution of lithium bromide, a heating source or a boiler, and requires maintenance. Therefore, there is a demand for a new cooling device which solves these problems of the prior art and does not destroy human beings, living things, or the environment, in particular, a refrigerating device which is kind to the global environment, is small in size, and has a low maintenance load.

[0004]

In order to achieve the above object, the present invention comprises, for example, a shell-and-tube type microtube group composed of a homogeneous membrane through which only gas can permeate, and the water-soluble refrigerant liquid is contained in the tube. While maintaining the surrounding space outside the tube under reduced pressure, the refrigerant gas inside the tube is degassed and separated through the homogeneous membrane, and the evaporation heat of the refrigerant gas is used. Then, we propose a microtube type cooling method characterized by cooling the water or aqueous solution remaining in the tube. In the invention according to claim 2, as a means for embodying such a cooling method, an aqueous refrigerant liquid is conducted into the microtube, and the tube surrounding space is connected to the suction side of the vacuum compressor, thereby We propose a micro-tube type cooling device that can degas and separate the refrigerant gas.

In this case, the refrigerant gas cycle in which the refrigerant gas separated from the microtube is conducted to the refrigerant gas absorber via the vacuum compressor, and the degassed separation of the refrigerant gas in the tube deprives the heat of the load and heat. It is preferable that a cold water cycle of water or an aqueous solution to be exchanged is merged with the absorber to repeatedly circulate the water-soluble refrigerant liquid. Although the gas-liquid contact type absorber shown in FIG. 1 may be used as the absorber, for example, as shown in FIG. 2, the absorber is constituted by a group of microtubes using a homogeneous membrane, Water or aqueous solution after heat exchange with load is conducted into the tube, the refrigerant gas compressed by the vacuum compressor is blown into the space around the tube group, and the refrigerant gas is passed through a homogeneous membrane to form water in the microtube. Alternatively, it may be configured to be absorbed in an aqueous solution. And preferably ammonia gas or methylamine for the refrigerant gas, and ammonium water for the aqueous solution passing through the microtube, by using an aqueous solution of methylamine, respectively, because the ammonia gas can be dissolved in water indefinitely, the heat removal effect. Is high and uses ammonia water as the aqueous solution,
It is easy to lower the temperature to 0 ° C or lower.

[0006]

[Function] The gas permeable membrane that constitutes the microtube has a mechanism of a homogeneous membrane, a porous membrane, and a heterogeneous membrane, but the permeable membrane of the present application should have the characteristics of a homogeneous membrane. It is better to use a flexible microtube. Such a homogeneous membrane is composed of dissolution of gas molecules into the membrane at the membrane interface, diffusion of dissolved gas molecules in the membrane, and dissolution of gas molecules from the membrane. . Then, a bundle of microtubes of the homogeneous permeable membrane of the silicone rubber membrane is constructed in a shell-and-tube type, the water-soluble refrigerant liquid is circulated in the tube, and the shell in the tube is decompressed by, for example, the vacuum compressor 2. As a result, only the ammonia gas in the ammonia water passing through the homogeneous membrane is separated from the homogeneous membrane of the silicone rubber tube and sucked into the vacuum compressor 2. At this time, the ammonia liquid evaporates from the ammonia refrigerant water in the tube and becomes a gas, so the evaporation heat is removed, and the ammonia refrigerant water becomes fresh water or dilute ammonia solution at the same time and the temperature drops, so that the load side needs to use it. Fall to temperature. Since the uniform membrane tube is a large number of thin tube bundles, the refrigerant water is dispersed in a fine liquid column converging, so that cooling by uniform evaporation is continuously performed.

The cooling water sent out from the microtube is used for air conditioning and other cooling loads, after which the cooling return water after the heat exchange is introduced into the absorber, while the ammonia gas compressed by the compressor is Jet into the absorber,
The ammonia gas is absorbed by the return water to become ammonia refrigerant water, which is again sent to the evaporator by the pump and flows into the microtube. The evaporator is a microtube dispersed in a thin tube shape, and 3000 to 6000 pieces are dispersed.
It is preferable to construct a reduced pressure sealed space in which the fine water is divided into books and becomes a thin dispersion flow corresponding to that number, is bound together with a microtube homogeneous membrane as a boundary, is housed in a shell, and the periphery thereof is sucked by a vacuum compressor.

In the conventional chiller cooling water device, the refrigerant and the water to be cooled are isolated (pipe) and the refrigerant cycle and the water to be cooled are not combined, but the present invention mixes and dissolves the refrigerant (ammonia) and the water to be cooled, It is greatly different in that it is placed in a microtube composed of a homogeneous membrane. The ammonia gas degassed and separated by the homogeneous membrane and the cooling return water are mixed in the absorber so that they can be repeatedly circulated. In this case, when the cold water discharged from the evaporator is 0 ° C. or more when it is separated into fresh water, it can be used as cooling water for cooling, and when it is the ammonia water in which residual ammonia is dissolved, the temperature is 0 ° C. or less. It is capable of freezing the temperature.

Further, in the conventional refrigeration cycle using the ammonia refrigerant, the ammonia gas separated by the evaporator needs a heat exchanger in a closed circuit between the closed load cold water circuit and the ammonia refrigerant by the expansion valve after the condensation. Although the structure becomes complicated, the present invention greatly simplifies the structure because a large number of homogeneous membrane microtubes serve as permeation evaporators and have a function of separating water and ammonia. As shown in FIG. 2, the absorber for absorbing the separated ammonia gas into the cooling return water may use the same type of membrane heat exchanger by reversing the gas flow of the ammonia as it is in the homogeneous membrane microtube. Since it is possible, it is advantageous in terms of manufacturing and heat balance. The absorber shown in FIG. 2 is the same as the microtube of the evaporator, but the flow of gas is reversed, and the absorber has an ammonia absorbing structure that penetrates from the outer diameter side of the microtube to the inside through the homogeneous membrane.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but merely illustrative examples. Nothing more than. FIG. 1 is a flow sheet diagram showing a cooling device according to an embodiment of the present invention. 1
Is a shell-end tube type evaporator (chiller), and a bundle of a large number of microtubes 3 formed by a homogeneous film described later is fixed to both ends of the shell 1A with resin plates 12 to hermetically seal the tube surrounding space 3A. The microtubes 3 are opened in the inner spaces of the shell end plates 13A and 13B that cover the resin plate 12 while maintaining the closed space.

The microtube 3 is formed of a silicon rubber film having a molecular structure of a bond between silicon and oxygen. There is no hole in this silicone rubber film, and because of the chemical relationship between gas and silicon, gas penetrates into the silicone rubber, moves, and passes through. It has the property of falling out. The outer diameter of the micro tube 3 is, for example, 250
μm, 320 μm, 320 μm, each inner diameter is 170 μm
m, 200 μm, 170 μm. Therefore, the film thickness is 40 μm, 60 μm, and 80 μm, respectively. The microtube 3 is for example 3000, it is 6,000, the effective membrane area are each 0.3 m ^2, a 0.74 m ^2.

The surrounding space 3A of the microtube 3 is connected to the suction side of the vacuum compressor 2 to maintain the surrounding space 3A in a substantially vacuum state. The discharge side of the vacuum compressor 2 is communicated with the inside of the absorber 5 via the heat exchanger 15 so that the ammonia gas compressed by the compressor 2 can be released into the absorber 5. What is specified here as the vacuum compressor 2 is not only the performance of not only the vacuum pump but also the gas compressor, but it has the role of simultaneously achieving vacuum and performing compression. Further, a liquid seal type so-called screw type compressor or a trochoid type positive displacement type compressor is suitable as the type of the vacuum compressor. In addition to one vacuum compressor, it is possible to combine a vacuum pump in the low stage and a compressor in the high stage in series. Further, the outlet side of the compressor 2 is connected to the absorber 5 via the load side heat exchanger 7, and the return cooling water, which has been deprived of heat by the load heat exchanger 7, comes into contact with the ammonia gas in the absorber 5. Configure as possible. Then, the ammonia refrigerant water in which the ammonia gas is dissolved by the contact is passed through the pump 9 to the evaporator 1
Will be led to the entrance side of. Reference numeral 8 is a return pipe for bringing the ammonia refrigerant water accumulated at the bottom of the absorber 5 into gas-liquid contact with the compressed ammonia gas again via the pump 16. Further, methylamine as a refrigerant and a methylamine aqueous solution of water as an absorbent can also be used. In addition, methyl alcohol as a refrigerant,
The absorbent may be an aqueous solution of lithium bromide.

Next, the operation of this embodiment will be described. The ammonia refrigerant water introduced into the micro tube 3 from the inner space of the shell end plate 13A on the inlet side of the evaporator 1 is applied with the water pressure by the pump 9, and the surrounding space 3A is sucked by the vacuum compressor 2 to be vacuumed. The ammonia gas dissolved in the ammonia water by being put through the gas passes through the homogeneous membrane of the microtube 3 and is sucked into the compressor 2 to be compressed. The compressed ammonia gas then passes through the conduit 10 and is introduced into the absorber 5 via the heat exchanger 15.

On the other hand, the ammonia aqueous solution in the tube 3 from which the ammonia gas has been deaerated and separated is cooled while removing the heat of vaporization from the water as the ammonia gas evaporates from the water in the process of passing through the microtube 3. Falls until reaches the saturation temperature. Since the microtubes 3 are 3000 or 6000 thin tubes, the aqueous solution is dispersed in the form of fine columns, so that the gas is uniformly degassed and the refrigerant gas is vaporized efficiently. Then, the cooling water cooled to, for example, about 7 ° C. in the tube 3 is deprived of heat by the load heat exchanger 6 from the outlet side shell end plate inner space 13B of the evaporator 1 and rises to about 12 ° C., and then returns. The cooling water is introduced into the absorber 5, and the ammonia is dissolved into vapor of the ammonia compressed while making gas-liquid contact with the compressed ammonia gas to become the ammonia refrigerant water, and stays at the bottom of the absorber 5. Then, the ammonia refrigerant water 4 accumulated at the bottom of the absorber 5 is again brought into gas-liquid contact with the ammonia gas through the pump 16 and the return pipe 8 to enhance its absorption efficiency. On the other hand, the ammonia refrigerant water accumulated at the bottom of the absorber 5 enters the evaporator 1 again by the pump 9 and is recirculated while repeating the above operation.

FIG. 2 shows another embodiment of the present invention, in which the absorber 5 has the same structure as the evaporator 1. That is, the high-pressure ammonia gas compressed by the compressor is absorbed from the outside of the microtube 3 through the homogeneous membrane into the return cooling water in the tube 3. Reference numeral 11 denotes an expansion tank for transporting ammonia refrigerant water, and a necessary amount of ammonia refrigerant water is supplied from the tank 11 to the evaporator 1 side. Since the operation and reference numerals of other systems are the same as those in FIG. 1, their explanations are omitted.

Therefore, in any of the above-described embodiments, the operation of the present invention can be smoothly achieved, and the amount of compression of the vacuum compressor 2 and the flow rate of the ammonia refrigerant water by the pump 9 are controlled to control the ammonia refrigerant water in the microtube 3. By adjusting the concentration, the temperature at the outlet of the evaporator 1 can be set to 0 ° C or lower or 0 ° C or higher.

[0017]

As described above, according to the present invention, the refrigerant gas in the ammonia refrigerant water or other aqueous refrigerant gas solution can be degassed and evaporated, and the evaporation heat can cool the water or the aqueous solution. In particular, in the present invention, the evaporation and the separation are simultaneously performed by the microtube 3 having a homogeneous film such as a silicone film, so that it is not necessary to use separate devices for each. Further, as in the absorption type refrigerator, the process of regeneration-coagulation-evaporation-absorption makes it possible to obtain cold water only by evaporation and absorption by using the vacuum compressor 2, so that the structure is extremely simplified.
Further, by adjusting the degree of vacuum of the vacuum compressor and the passage speed of the aqueous refrigerant solution in the microtube, cooling water having a temperature of 0 ° C. or lower or 0 ° C. or higher can be freely obtained, and temperature control is easy. It is also environmentally preferable because it uses ammonia water without using CFCs, and because it does not directly compress and expand the ammonia liquid like the conventional ammonia refrigeration cycle, its risk is greatly mitigated. It It has various remarkable effects.

[Brief description of drawings]

FIG. 1 is a flow sheet diagram showing a cooling device according to an embodiment of the present invention.

FIG. 2 is a flow sheet diagram showing a cooling device according to another embodiment of the present invention.

[Explanation of symbols]

 1 Evaporator 2 Vacuum Compressor 3 Micro Tube 3A Surrounding Space 5 Absorber 9 Pump

Claims (5)

[Claims] 1. A water-refrigerant liquid is introduced into a microtube made of a homogeneous membrane that allows only gas to permeate, and the surrounding space outside the tube is maintained under reduced pressure, and the refrigerant in the tube is passed through the homogeneous membrane. A microtube cooling method characterized in that the gas is degassed and separated, and the heat or vaporization of the refrigerant gas is used to cool the water or aqueous solution remaining in the tube. 2. A water-refrigerant liquid is introduced into a microtube made of a homogeneous membrane that allows only gas to pass therethrough, and the space around the tube is connected to the suction side of a vacuum compressor to degas the refrigerant gas in the tube. Microtube cooling device characterized by being separable 3. A refrigerant gas cycle in which refrigerant gas separated from the microtube is conducted to a refrigerant gas absorber via a vacuum compressor, and heat is removed by deaeration and separation of the refrigerant gas in the tube, so that load and heat are absorbed. The microtube type cooling device according to claim 2, wherein a cold water cycle of water or an aqueous solution to be exchanged is merged with the absorber. 4. The absorber is composed of a group of microtubes using a homogeneous membrane, and water or an aqueous solution after heat exchange with a load is conducted into the microtubes, and the vacuum compressor is provided in a space around the tube group. 4. The microtube type cooling device according to claim 3, wherein the refrigerant gas compressed by the method is blown into the water or the aqueous solution in the microtube to absorb the refrigerant gas through the homogeneous film. 5. Ammonia or methylamine is used as the refrigerant gas, and ammonia water or methylamine aqueous solution is used as the aqueous solution passing through the microtube, respectively.
The described microtube type cooling device.