CN105972724A - Dehumidification device and method for three-fluid film - Google Patents

Abstract

The invention proposes a coaxial three-fluid membrane dehumidification device, which is mainly composed of a membrane tube, a metal sleeve and a shell. The three fluids are cold water, humid air, and hot water from the inside to the outside. Cold water flows in the innermost membrane tube, moist air flows in the annular channel between the membrane tube and the casing, and hot water flows between the casing and the casing. Flow in the annular channel between. The cold water provides a lower water pressure, forming a water vapor partial pressure difference with the humid air with a high water pressure, and the water vapor will enter the cold water through the membrane holes under the action of the water vapor partial pressure difference on both sides of the membrane, so as to achieve the purpose of dehumidification . The function of the hot water on the outermost side of the three-fluid film dehumidification device is to maintain the temperature of the humid air in the casing so that it is always higher than the dew point temperature so as to avoid condensation. Compared with the traditional condensation dehumidification method, three-fluid membrane dehumidification has significant advantages in some special fields (such as the humidity control in the cabin of manned spacecraft).

Description

Three-fluid film dehumidification device and method

technical field

The invention relates to a three-fluid membrane dehumidification device and method suitable for air dehumidification in the spaceflight microgravity environment.

Background technique

At present, on manned spacecraft, the dehumidification of the air in the cabin mainly adopts condensation dehumidification technology, which reduces the temperature of the humid air to below the dew point temperature, thereby condensing liquid water to achieve the purpose of dehumidification. However, there are some problems with this dehumidification technology. Since condensation dehumidification is a strongly coupled process of temperature and humidity, the dehumidification of humid air will greatly reduce the temperature at the same time. It is difficult to control temperature and humidity independently, and sometimes problems cannot be considered. Moreover, under the weightless conditions of the spacecraft, the condensed liquid water cannot be naturally separated from the air by gravity. At this time, a gas-liquid separator must be specially installed to separate and store the liquid water. This gas-liquid separator will increase the weight of the system, and its complicated internal structure will bring inconvenience to future maintenance.

The cold water membrane dehumidification solution is to use the characteristics of low water vapor partial pressure on the surface of cold water. Under the action of the water vapor partial pressure difference on both sides of the membrane, water vapor will pass through the membrane material from humid air into cold water to achieve the purpose of dehumidification. In terms of dehumidification principle, cold water film dehumidification directly relies on water vapor partial pressure difference to achieve dehumidification, but mass transfer is also accompanied by certain heat transfer, so it is necessary to further decouple heat transfer and mass transfer.

Contents of the invention

The invention provides a three-fluid membrane dehumidification device, which further realizes the decoupling of heat transfer and mass transfer through the hot water outside the humid air, realizes the separation of water vapor and air in the gaseous state while dehumidifying, and saves the gas The liquid separator can also dehumidify efficiently under the condition of weightlessness, and realize the complete recovery of water vapor in the airtight cabin. At the same time, the system process is simplified, the weight and complexity are reduced, and the system reliability and maintainability are improved.

A three-fluid membrane dehumidification device according to an embodiment of the present invention utilizes the characteristics of low water vapor partial pressure on the surface of cold water to allow water vapor to pass through the membrane material under the action of the water vapor partial pressure difference on both sides of the membrane to achieve the purpose of dehumidification , the hot water in the outermost metal tube can ensure that the temperature of the humid air is higher than the dew point temperature, preventing condensation of the humid air.

In the three-fluid membrane dehumidification device according to one embodiment of the present invention, cold water flows inside the membrane tube, and humid air flows in reverse outside the membrane tube, and the water vapor and sensible heat in the humid air enter the cold water through the membrane tube wall and are taken away , the moisture content is reduced, so as to achieve the purpose of dehumidification, and the temperature is also reduced. As the temperature of the humid air drops below the dew point temperature, condensation will occur. Therefore, there is a hot water flow in the same direction as the humid air outside the humid air. The heat of the hot water releases sensible heat to the humid air through the stainless steel sleeve wall to maintain the temperature of the humid air. above the dew point temperature.

According to one aspect of the present invention, a three-fluid membrane dehumidification device is provided, which is characterized by comprising: a hot water module, a wet air module, and a cold water module,

in,

The cold water module includes a membrane tube that passes through the wet air module and remains coaxial with the thin metal tube,

The humid air module includes a thin metal tube that passes through the hot water module and is coaxial with the thick metal tube.

According to another aspect of the present invention, a three-fluid membrane dehumidification method is provided, characterized in that it comprises:

Make the hot water flow into the thick metal pipe from the first three-way joint, flow in the thick metal pipe and exchange heat with the moist air in the thin metal pipe through the wall of the thin metal pipe,

Let the humid air flow into the thin metal tube from the second three-way joint, flow in the thin metal tube and exchange heat and moisture with the cold water in the membrane tube through the tube wall of the membrane tube, wherein the cold water in the membrane tube reacts with the humid air outside the membrane tube to the flow,

in,

The membrane tube passes through and is coaxial with the moist air module comprising thin metal tubes,

The thin metal tubes pass through the hot water module including the thick metal tubes and are coaxial with the thick metal tubes,

The membrane tube is made of one-way moisture-permeable membrane material,

The water vapor in the humid air outside the membrane tube enters the cold water in the membrane tube through the membrane holes on the one-way moisture-permeable membrane material and is taken away by the cold water,

Part of the heat of the humid air enters the cold water through the heat-moisture exchange, and the cold water cannot permeate through the membrane to the humid air side.

The beneficial effects of the present invention include:

Compared with the current condensing dehumidification mode, which relies on a large temperature difference to lower the temperature of the humid air below the dew point temperature to liquefy and separate the water vapor to achieve dehumidification, the three-fluid membrane dehumidification mainly relies on the water vapor partial pressure difference on both sides of the membrane. The transmembrane mass transfer of water vapor separates water vapor from air directly in the gaseous state, avoiding an additional gas-liquid separation process, simplifying the process of the dehumidification system to a certain extent, reducing the weight of the system, improving reliability and maintainability sexual enhancement. In addition, the three-fluid membrane dehumidification device realizes the decoupling of heat transfer and mass transfer to a certain extent, so that temperature and humidity can be controlled relatively independently.

Description of drawings

FIG. 1 is a schematic diagram of an overall system of an embodiment of the present invention.

Fig. 2 is a schematic diagram of a hot water module according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a humid air module according to an embodiment of the present invention.

Fig. 4 is a schematic diagram of a cold water module according to an embodiment of the present invention.

detailed description

The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figures 1-4, according to a specific embodiment of the present invention, it includes: a hot water module A, a wet air module B, and a cold water module C. In the example shown in Figure 1, the membrane tube (9) of the cold water module C Set inside the thin metal tube (5) of the humid air module B and kept coaxial, the membrane tube (9) is sealed with the joint (8) to isolate the humid air from the cold water; the seal is for example by potting Glue the seal. The thin metal pipe (5) of the humid air module B is set inside the thick metal pipe (1) of the hot water module A, and the thin metal pipe (5) is kept coaxial with the thick metal pipe (1) and passes through the second ferrule joint (4) Separate the hot water from the cold water. In a specific embodiment, the thin metal tube (5) and the second ferrule joint (4) are sealed by potting glue to prevent foreign impurities from entering the interior of the device.

As shown in Figure 2, in one embodiment of the present invention, the hot water module (A) includes a thick metal pipe (1), a first ferrule joint (2), a first tee joint (3), a second Compression fittings (4). In a specific example as shown in Fig. 2, the thick metal pipe (1) and the first ferrule joint (2) are locked by the ferrule nut inside the ferrule joint, resist the ferrule, and cut into the pipe to seal. The first ferrule joint (2), the second ferrule joint (4) and the first three-way joint (3) are all tightly connected by threads.

As shown in Figure 3, according to a specific embodiment of the present invention, the humid air module (B) includes a thin metal pipe (5), a third ferrule joint (6), a second three-way joint (7), a common joint ( 8). In a specific example as shown in Fig. 3, the thin metal tube (5) and the third ferrule joint (6) are locked by the ferrule nut inside the ferrule joint, resist the ferrule, and cut into the pipe to seal. The third ferrule joint (6), the ordinary joint (8) and the second three-way joint (7) are all tightly connected by threads.

As shown in Fig. 4, according to a specific embodiment of the present invention, the cold water module (C) includes a membrane tube (9). In a specific embodiment of the present invention, the membrane tube (9) is made of PVDF membrane.

According to the operation of the three-fluid membrane dehumidification device of the present invention, hot water flows in from the first three-way joint (3), flows in the thick metal pipe (1) and conducts heat through the pipe wall of the thin metal pipe (5) and the moist air in the pipe. exchange. Humid air flows in from the second three-way joint (7), flows in the thin metal tube (5) and passes through the tube wall of the membrane tube (9) to exchange heat and moisture with the cold water in the membrane tube (9). (9) and the humid air outside the film tube (9) flows in reverse.

The three-fluid membrane dehumidification device according to the present invention relies on the water vapor partial pressure difference to cause the water vapor to transmembrane mass transfer, realizes the direct separation of water vapor and air in the gaseous state, and achieves the purpose of dehumidification, and no condensation occurs during the dehumidification process, It avoids the additional gas-liquid separation process, solves the difficult problem of gas-liquid separation under the weightlessness of aerospace, and realizes the complete recovery of water vapor in the airtight cabin.

The above is only one example of the present invention; the specific application examples do not constitute any limitation to the protection scope of the present invention. All technical solutions formed by equivalent transformation or equivalent transformation fall within the protection scope of the present invention.

Claims (10)

1. A three-fluid membrane dehumidification device, comprising:

a hot water module (A) is arranged in the water tank,

a humid air module (B),

a cold water module (C),

wherein,

the cold water module (C) comprises a membrane tube (9), the membrane tube (9) passes through the humid air module (B) and is coaxial with the thin metal tube (5),

the wet air module (B) comprises a thin metal tube (5), the thin metal tube (5) passing through the hot water module (A) and being coaxial with the thick metal tube (1).

2. The three-fluid membrane dehumidification device of claim 1, wherein:

the hot water module (A) comprises a thick metal pipe (1), a first clamping sleeve joint (2), a first three-way joint (3) and a second clamping sleeve joint (4),

the wet air module (B) further comprises a third clamping sleeve joint (6), a second three-way joint (7) and a common joint (8).

3. The three-fluid membrane dehumidification device of claim 2, wherein in operation:

hot water flows in from the first three-way joint (3) and enters the thick metal pipe (1) through the second ferrule joint (4),

the second ferrule (4) isolates hot water from humid air,

the wet air flows in from the second three-way joint (7) and enters the thin metal pipe (5) through the third clamping sleeve joint (6),

the second three-way joint (7) is sealed with the membrane tube (9) to separate the wet air from the cold water in the membrane tube (9).

4. The three-fluid membrane dehumidification device of claim 2 or 3, wherein:

the membrane tube (9) is made of one-way moisture permeable membrane material,

water vapor in the humid air outside the membrane tube (9) enters the cold water in the membrane tube (9) through membrane pores on the one-way moisture-permeable membrane material and is taken away by the cold water, partial heat of the humid air enters the cold water through heat conduction and heat convection, and the cold water cannot permeate the membrane to the humid air side.

5. The three-fluid membrane dehumidification device of claim 2 or 3, wherein:

the hot water in the thick metal tube (1) transfers heat to the humid air in the thin metal tube (5), thereby maintaining the temperature of the humid air above the dew point temperature.

6. The three-fluid membrane dehumidification device of claim 2 or 3, wherein:

the sealing between the second three-way joint (7) and the membrane tube (9) in the common joint (8) is realized by pouring sealant in the common joint (8).

7. A three-fluid membrane dehumidification method, comprising:

hot water flows into the thick metal pipe (1) from the first three-way joint (3), flows in the thick metal pipe (1) and exchanges heat with wet air in the thin metal pipe (5) through the pipe wall of the thin metal pipe (5),

the wet air flows into the thin metal pipe (5) from the second three-way joint (7) and flows in the thin metal pipe (5) and generates heat and moisture exchange with the cold water in the membrane pipe (9) through the pipe wall of the membrane pipe (9), wherein the cold water flows in the membrane pipe (9) in the opposite direction of the wet air outside the membrane pipe (9),

wherein,

the membrane tube (9) passes through a humid air module (B) comprising a thin metal tube (5) and is coaxial with the thin metal tube (5),

the thin metal tube (5) passes through the hot water module (A) comprising the thick metal tube (1) and is coaxial with the thick metal tube (1),

the membrane tube (9) is made of one-way moisture permeable membrane material,

the water vapor in the wet air outside the membrane tube (9) enters the cold water in the membrane tube (9) through the membrane pores on the one-way moisture-permeable membrane material and is carried away by the cold water,

part of the heat of the humid air passes through the heat moisture exchange into the cold water, which cannot penetrate through the membrane to the humid air side.

8. The three-fluid membrane dehumidification method of claim 7, wherein:

the second three-way joint (7) and the membrane tube (9) are sealed by pouring sealant in the common joint (8).

9. The three-fluid membrane dehumidification method of claim 7, wherein:

the hot water in the thick metal tube (1) transfers heat to the humid air in the thin metal tube (5), thereby maintaining the temperature of the humid air above the dew point temperature.

10. The three-fluid membrane dehumidification method of claim 7, wherein:

the heat-moisture exchange includes heat exchange by heat conduction and heat convection.