CN205014519U - Energy -conserving dehumidification system of precooling - Google Patents

Abstract

The utility model discloses a precooling energy-saving dehumidification system, which belongs to the field of air conditioning. The dehumidification system includes a housing and a dehumidification unit arranged in the housing. The dehumidification unit is equipped with a compressor, a water-cooled condenser, an air-cooled condenser, and an expansion valve. , surface cooler and air-gas plate heat exchanger; there is a first refrigerant circulation loop between the compressor, water-cooled condenser, expansion valve and surface cooler; compressor, air-cooled condenser, expansion valve and surface cooler There is a second refrigerant circulation loop between them; there is a first cooling water circulation loop between the water-cooled condenser and the external cooling water system; the indoor air flows through the air-air plate heat exchanger, the surface cooler, and the air-air plate heat exchanger The air dehumidification channel is provided on the passage for sending into the room after the heater and the air-cooled condenser. The dehumidification system of the utility model has the advantages of simple structure, low energy consumption and good stability.

Description

A pre-cooling energy-saving dehumidification system

technical field

The utility model relates to a dehumidification system in the field of air conditioning, in particular to a heat pump refrigeration dehumidification system with a precooling function.

Background technique

In the field of air conditioning, air dehumidification is one of the important procedures. Traditional refrigerated dehumidifiers mainly use the principle of compression refrigeration to cool the air and remove water vapor to achieve the purpose of dehumidification. However, the dehumidification load in this dehumidification method is borne by the refrigeration system, resulting in a low dehumidification capacity per unit electric energy of the overall unit and a single function. Based on this situation, those skilled in the art have researched and developed a fresh air dehumidifier with two systems, such as CN1699855, which is provided with a casing and an evaporator, an air-cooled condenser, a compressor, a water-cooled condenser, a dry filter evaporator, expansion valve, hot gas bypass valve, water baffle, fan, and a cooling coil in front of the evaporator, which is connected in series with a water-cooled condenser to reduce the air handling range of the refrigeration system. After absorbing heat, it enters the water-cooled condenser. Compared with ordinary dehumidifiers, the dehumidification capacity per unit electric energy is higher than that of ordinary dehumidifiers. However, in the actual working process, the temperature of the air before entering the cooling coil is basically 26°C, and the air temperature drops to about 10°C after being cooled by the evaporator. Because the temperature is too low, it is not suitable to be directly sent into the room. Heating the air results in a secondary waste of energy.

Utility model content

The purpose of the utility model is to provide a pre-cooling energy-saving dehumidification system, which has the advantages of simple structure, low energy consumption and good stability.

In order to solve the technical problems of low dehumidification capacity per unit electric energy, single function, and waste of energy in the prior art, the utility model is a pre-cooling energy-saving dehumidification system, which includes a shell and a dehumidification unit arranged in the shell. The dehumidification unit is equipped with a compressor, a water-cooled condenser, an air-cooled condenser, an expansion valve, a surface cooler and an air-gas plate heat exchanger; a first refrigeration unit is installed between the compressor, water-cooled condenser, expansion valve and the surface cooler. Mass circulation circuit, there is a second refrigerant circulation circuit between the compressor, air-cooled condenser, expansion valve and surface cooler, the first refrigerant circulation circuit and the second refrigerant circulation circuit are in normal mode and energy-saving Alternate operation in this mode; there is a first cooling water circulation loop between the water-cooled condenser and the external cooling water system; the indoor air flows through the air-air plate heat exchanger, surface cooler, air-air plate heat exchanger, and air-cooled condenser in sequence The passage for sending it into the room is provided with an air dehumidification duct, and a fan is provided at the entrance of the air dehumidification duct.

Further, the utility model is a pre-cooling energy-saving dehumidification system, wherein, the water-cooled condenser is provided with a first refrigerant channel and a cooling water channel, and the air-cooled condenser is provided with a second refrigerant channel, which represents The cooler is provided with a third refrigerant channel; the air-gas plate heat exchanger is provided with a first air passage and a second air passage intersected; the first refrigerant circulation loop and the second refrigerant circulation The flow direction of the refrigerant is converted by setting a three-way regulating valve between the circuits;

The first refrigerant circulation circuit is that the liquid outlet of the compressor is connected to the liquid inlet of the three-way regulating valve through a pipeline, and one liquid outlet of the three-way regulating valve is connected with the first refrigerant in the water-cooled condenser through a pipe. The liquid inlet of the channel, the liquid outlet of the first refrigerant channel in the water-cooled condenser is connected to the liquid inlet of the expansion valve through a pipe, and the liquid outlet of the expansion valve is connected to the third refrigerant channel in the surface cooler through a pipe. The liquid inlet, the liquid outlet of the third refrigerant channel in the surface cooler is connected to the liquid inlet of the compressor through a pipeline;

The second refrigerant circulation circuit is that the liquid outlet of the compressor is connected to the liquid inlet of the three-way regulating valve through a pipeline, and the other liquid outlet of the three-way regulating valve is connected to the second refrigeration unit in the air-cooled condenser through a pipeline. The liquid inlet of the working medium channel, the liquid outlet of the second refrigerant working medium channel in the air-cooled condenser is connected to the liquid inlet of the expansion valve through the pipe, and the liquid inlet of the expansion valve is connected to the third refrigerant in the surface cooler through the pipe. The liquid inlet of the refrigerant channel, and the liquid outlet of the third refrigerant channel in the surface cooler is connected to the liquid inlet of the compressor through a pipeline;

The first cooling water circulation loop is that the liquid inlet and the liquid outlet of the cooling water channel in the water-cooled condenser are respectively communicated with the external cooling water pipeline through pipelines to form a loop;

The air dehumidification air channel is that the indoor air flows through the first air channel in the air-air plate heat exchanger, the surface cooler, the second air channel in the air-air plate heat exchanger, and the air-cooled condenser in sequence, and then is sent into the Indoor passage.

Further, the utility model is a precooling energy-saving dehumidification system, wherein a first one-way Valve: a second one-way valve is provided on the pipeline between the liquid outlet of the second refrigerant channel in the air-cooled condenser and the liquid inlet connected to the expansion valve.

Further, the utility model is a pre-cooling energy-saving dehumidification system, wherein, the front end of the air-gas plate heat exchanger in the air dehumidification air duct is also provided with a coil cooler, and the coil cooler is connected with the external cooling water system There is a second cooling water circulation loop between them.

Further, the utility model is a pre-cooling energy-saving dehumidification system, which also includes an electrical control unit, and the electrical control unit is used to control the power distribution and operating parameters of each component in the unit.

Compared with the prior art, a precooling energy-saving dehumidification system of the utility model has the following advantages: as a dehumidification unit in the dehumidification system, ① the utility model is equipped with a compressor, a water-cooled condenser, an air-cooled condenser, an expansion valve, The surface cooler and the air-gas plate heat exchanger, and the first refrigerant circulation circuit is set between the compressor, the water-cooled condenser, the expansion valve and the surface cooler, and the compressor, the air-cooled condenser, the expansion valve and the surface cooling The second refrigerant circulation loop is set between the condensers, the first cooling water circulation loop is set between the water-cooled condenser and the external cooling water, and the air flows through the air-air plate heat exchanger, the surface cooler, and the air-air plate heat exchanger in sequence. Air dehumidification air duct is set in the passageway that sends air into the room after the condenser and air-cooled condenser. Thus, the utility model can be operated in different modes by controlling the opening or closing of the first refrigerant circulation circuit, the second refrigeration refrigerant circulation circuit and the first cooling water circulation circuit. Specifically: when there are people in the room under normal conditions, by shutting down the second refrigerant circulation loop and opening the first refrigeration refrigerant circulation loop and the first cooling water circulation loop, the utility model works in the normal mode, and the refrigeration The working medium circulates in the first refrigerant circulation circuit. On the one hand, the refrigerant absorbs heat at the surface cooler and exchanges heat with the air passing through, reducing the air temperature to achieve the purpose of freezing and dehumidification. On the other hand, The refrigerant releases heat at the water-cooled condenser and exchanges heat with the first cooling water circulation loop, and transfers the heat through the first cooling water circulation loop to control the air temperature within an appropriate range. In normal mode, due to shutdown The second refrigerant circulation circuit is disabled, and the air-cooled condenser does not work. In the case of no one in the room during the holiday, it is only necessary to dehumidify the indoor air without controlling the air temperature. At this time, by opening the second refrigerant circulation loop and closing the first refrigeration refrigerant circulation loop and the first cooling water circulation circuit, so that the utility model works in the energy-saving mode, and the refrigerant circulates in the second refrigerant circulation circuit. On the one hand, the refrigerant absorbs heat at the surface cooler and is combined with the The air performs heat exchange to reduce the air temperature to achieve the purpose of freezing and dehumidification; on the other hand, the refrigerant releases heat at the air-cooled condenser and exchanges heat with the passing air to increase the air temperature. A refrigerating working medium circulation loop and a corresponding first cooling water circulation loop can greatly reduce energy consumption and achieve the purpose of energy saving. ②In this utility model, by setting the air-air plate heat exchanger, the indoor air flows through the first air channel in the air-air plate heat exchanger, the surface cooler, the second air channel in the air-air plate heat exchanger, and the air. After cooling the condenser, it is sent into the room. During this process, the air flowing through the surface cooler will exchange heat with the refrigerant to reduce the temperature. When it flows through the second air channel in the air-gas plate heat exchanger , it will be used as a cold source to exchange heat with the air that has just entered the first air passage of the gas plate heat exchanger, and pre-cool the air that has just entered the first air passage of the gas plate heat exchanger, and its own temperature will rise accordingly , can avoid the situation that the temperature is too low. This structural design can not only make full use of the cooling energy of the cold air, realize the recycling of energy, and reduce energy consumption; The air temperature in the second air duct reaches a relative balance, which enhances the stability of the dehumidification system.

A pre-cooling energy-saving dehumidification system of the present invention will be further described in detail below in conjunction with the specific implementation shown in the accompanying drawings:

Description of drawings

Fig. 1 is the schematic diagram of the specific embodiment of a kind of precooling energy-saving dehumidification system of the present invention;

In the figure, 1 is a compressor, 2 is a water-cooled condenser, 3 is an air-cooled condenser, 4 is an expansion valve, 5 is a surface cooler, 6 is an air-gas plate heat exchanger, 7 is a three-way regulating valve, and 8 is a The first one-way valve, 9 is the second one-way valve, and 10 is the coil cooler.

detailed description

As shown in Figure 1, a specific embodiment of a pre-cooling energy-saving dehumidification system in the utility model generally includes a housing and a dehumidification unit arranged in the housing. The dehumidification unit is provided with a compressor 1, a water-cooled condenser 2, an air Cold condenser 3, expansion valve 4, surface cooler 5 and air-to-gas plate heat exchanger 6, and a first refrigerant circulation circuit is set between compressor 1, water-cooled condenser 2, expansion valve 4 and surface cooler 5 , so that the first refrigerant circulation loop and the second refrigerant circulation loop operate alternately in the normal mode and the energy-saving mode; a second compressor is set between the compressor 1, the air-cooled condenser 3, the expansion valve 4 and the surface cooler 5 2. Refrigerating medium circulation loop; the first cooling water circulation loop is set between the water-cooled condenser 2 and the external cooling water; at the same time, the indoor air flows through the air-air plate heat exchanger 6, the surface cooler 5, and the air-air plate heat exchanger in sequence. Heater 6, air-cooled condenser 3 send into indoor passage again and be set as air dehumidification air duct, and blower fan is set at the entrance of air dehumidification air duct, so that guide indoor air to flow along air dehumidification air duct.

As a specific embodiment, the specific structure of the dehumidification unit is that the first refrigerant passage and the cooling water passage are arranged in the water-cooled condenser 2, the second refrigerant passage is arranged in the air-cooled condenser 3, and the surface cooler 5 The third refrigerant channel is set in the middle; the first air channel and the second air channel arranged crosswise are set in the gas-gas plate heat exchanger 6 .

The liquid outlet of compressor 1 is connected to the liquid inlet of three-way regulating valve 7 through a pipeline, and one liquid outlet of three-way regulating valve 7 is connected to the liquid inlet of the first refrigerant channel in water-cooled condenser 2 through a pipeline , the liquid outlet of the first refrigerant channel in the water-cooled condenser 2 is connected to the liquid inlet of the expansion valve 4 through a pipeline, and the liquid outlet of the expansion valve 4 is connected to the third refrigerant channel in the surface cooler 5 through a pipeline Let the liquid outlet of the third refrigerant passage in the surface cooler 5 be connected to the liquid inlet of the compressor 1 through a pipeline to form a first refrigerant circulation loop. And allow another liquid outlet of the three-way regulating valve 7 to be connected to the liquid inlet of the second refrigerant passage in the air-cooled condenser 3 through a pipeline, so that the liquid outlet of the second refrigerant passage in the air-cooled condenser 3 The port is connected to the liquid inlet of the expansion valve 4 through a pipeline, and the liquid inlet of the expansion valve 4 is connected to the liquid inlet of the third refrigerant channel in the surface cooler 5 through a pipe, so that the third refrigerant in the surface cooler 5 The liquid outlet of the channel is connected to the liquid inlet of the compressor 1 through a pipeline to form a second refrigerant circulation loop. With the above structure, the flow direction of the refrigerant can be switched through the three-way regulating valve 7, and then the operation of the first refrigerant circulation loop and the second refrigeration refrigerant circulation loop can be controlled.

At the same time, let the liquid inlet and the liquid outlet of the cooling water channel in the water-cooled condenser 2 communicate with the external cooling water pipeline through the pipeline respectively and form a loop; to form the first cooling water circulation loop; let the indoor air flow through the air-gas plate exchange The first air duct in the heater 6, the surface cooler 5, the second air duct in the air-gas plate heat exchanger 6, and the air-cooled condenser 3 are sent into the room to form an air dehumidification air duct.

With the above structure, the dehumidification unit of the present invention can work in different modes by controlling the opening or closing of the first refrigerant circulation circuit, the second refrigerant circulation circuit and the first cooling water circulation circuit. Specifically: when there are people in the room under normal conditions, by shutting down the second refrigerant circulation loop and opening the first refrigeration refrigerant circulation loop and the first cooling water circulation loop, the utility model works in the normal mode, and the refrigeration The working medium circulates in the first refrigerant circulation circuit. On the one hand, the refrigerant absorbs heat at the surface cooler 5 and exchanges heat with the air passing through, reducing the air temperature to achieve the purpose of freezing and dehumidification. On the other hand, , the refrigerant releases heat at the water-cooled condenser 2 and exchanges heat with the first cooling water circulation loop, and transfers the heat through the first cooling water circulation loop to control the air temperature within an appropriate range. In normal mode, due to The second refrigerating medium circulation loop is shut down, and the air-cooled condenser 3 does not work. In the case of no one in the room during the holiday, there is no need to cool down the air. By opening the second refrigerant circulation loop and shutting down the first refrigeration refrigerant circulation loop and the first cooling water circulation loop, the utility model works In the energy-saving mode, the refrigerant circulates in the second refrigerant circulation circuit. On the one hand, the refrigerant absorbs heat at the surface cooler 5 and exchanges heat with the air passing through, reducing the air temperature to achieve freezing. The purpose of dehumidification; on the other hand, the refrigerant releases heat at the air-cooled condenser 3 and exchanges heat with the air passing through, so that the temperature of the air increases. A cooling water circulation loop can greatly reduce energy consumption and achieve the purpose of energy saving. At the same time, the utility model arranges the air-gas plate heat exchanger 6, and makes the indoor air flow through the first air passage in the air-gas plate heat exchanger 6, the surface cooler 5, and the air-gas plate heat exchanger 6. The second air duct and the air-cooled condenser 3 are then sent into the room. During this process, the air flows through the air-gas plate exchanger 6 twice, and the air after passing through the surface cooler 5 will exchange heat with the refrigerant The temperature is lowered, and when it flows through the second air passage in the air-gas plate heat exchanger 6, it will be used as a cold source to exchange heat with the air that has just entered the first air passage in the air-gas plate heat exchanger 6, and the air that has just entered the first air passage of the air-gas plate heat exchanger 6 The air in the first air passage in the air-air plate heat exchanger 6 is pre-cooled, and its own temperature rises accordingly, which can avoid the situation that the temperature is too low. This structural design can not only make full use of the cold energy of the cold air, realize the recycling of energy, reduce energy consumption, but also make the temperature of the air flowing through the first air duct and the air temperature flowing through the second air duct reach the same level. balance, thereby enhancing the stability of the dehumidification system.

It should be noted that the first refrigerant circulation circuit and the second refrigerant circulation circuit in the above connection relationship can simplify the structure, reduce the volume of the dehumidification unit, and reduce the cost accordingly, but the connection relationship is not limited to the above listed In this way, two liquid inlets and two liquid outlets can also be set on the compressor 1, which are respectively connected to the water-cooled condenser 2 and the air-cooled condenser 3 through pipes, and are connected with the expansion valve 4 and the surface cooler 5 to form a The first refrigerant circulation circuit and the second refrigerant circulation circuit, in practical applications, control the first refrigerant circulation circuit or The opening or closing of the second refrigerant circulation circuit can also achieve the purpose of the utility model.

As an optimized solution, in this specific embodiment, a first one-way valve 8 is arranged on the pipeline between the liquid outlet of the first refrigerant channel in the water-cooled condenser 2 and the liquid inlet of the expansion valve 4; A second check valve 9 is arranged on the pipeline between the liquid outlet of the second refrigerant channel in the cold condenser 3 and the liquid inlet connected to the expansion valve 4 . The purpose of setting the first one-way valve 8 and the second one-way valve 9 is mainly to control the flow direction of the refrigerant in the first refrigerant circulation circuit and the second refrigerant circulation circuit to avoid unnecessary energy loss, thereby Improve efficiency. It should be noted that the first one-way valve 8 and the second one-way valve 9 are not necessary. If the first one-way valve 8 and the second one-way valve 9 are not provided, the three-way regulating valve 7 can also realize the control of refrigeration operation. The flow direction of the refrigerant in the first refrigerant circulation circuit and the second refrigerant circulation circuit, but the refrigerant will flow into unnecessary channels and perform heat exchange, resulting in energy loss and affecting efficiency.

As an optimized solution, in this specific embodiment, a coil cooler 10 is also arranged at the front end of the air-gas plate heat exchanger 6 in the air dehumidification duct, and the liquid inlet and outlet of the coil cooler 10 pass through The pipeline communicates with the external cold water to form a second cooling water circulation loop. By setting the coil cooler 10 and the second cooling water circulation loop, the air flowing through the tube cooler 10 can exchange heat with the cooling water in the second cooling water circulation loop, and the air can be cooled, thereby further improving the efficiency of the utility model. Freeze dehumidification ability and dehumidification effect.

It should be pointed out that the utility model is provided with an electrical control unit (not shown in the figure), through which the power distribution and operating parameters of each component in the dehumidification system are controlled and adjusted, which can improve the degree of automation management and ensure Stability of unit operation. The electrical control unit in the utility model mainly includes devices such as detection sensors, actuators, DDC or PLC single-chip microcomputers.

In order to help those skilled in the art understand the utility model, the operation process of the utility model is briefly described below. First of all, it needs to be explained that the utility model operates in two modes:

Under normal conditions, when there are people in the room, it will run in the normal mode. The specific process is as follows:

(1) Shut down the second refrigerant circulation circuit, open the first refrigerant circulation circuit and the first cooling water circulation circuit, make the refrigerant circulate in the first refrigerant circulation circuit, and make the cooling water flow in the first Circulating operation in the cooling water circulation loop;

(2) Turn on the fan to guide the indoor air to flow through the first air passage in the air-gas plate heat exchanger 6, the surface cooler 5, the second air passage in the air-gas plate heat exchanger 6, and the air-cooled condenser 3 and then sent indoors;

(3) Make the refrigerating medium release heat at the water-cooled condenser 2 and perform heat exchange with the cooling water, and make the refrigerating medium absorb heat at the surface cooler 5 and perform heat exchange with the air.

When the coil cooler 10 is set, the second cooling water circulation circuit should also be opened in the above step (1), and in the above step (2), the indoor air should be allowed to flow through the first air-gas plate heat exchanger 6 Before the first air duct, it flows through the coil cooler 10 and exchanges heat with the cooling water in the second cooling water circulation loop.

When there is no one in the room during holidays, it will run in energy-saving mode. The specific process is as follows:

(1) Open the second refrigerant circulation loop, shut down the first refrigeration refrigerant circulation loop and the first cooling water circulation loop, so that the refrigerant refrigerant circulates in the second refrigeration refrigerant circulation loop;

(2) Turn on the fan to guide the indoor air to flow through the first air passage in the air-gas plate heat exchanger 6, the surface cooler 5, the second air passage in the air-gas plate heat exchanger 6, and the air-cooled condenser 3 and then sent indoors;

(3) Make the refrigerating medium release heat at the air-cooled condenser 3 and perform heat exchange with the air, and make the refrigerating medium absorb heat at the surface cooler 5 and perform heat exchange with the air.

Similarly, when the coil cooler 10 is set, the second cooling water circulation loop should also be shut down in the above step (1), and in the above step (2), the indoor air should be allowed to flow through the air-gas plate heat exchanger Before the first air duct in 6, it flows through the coil cooler 10 and exchanges heat with the cooling water in the second cooling water circulation loop.

The above embodiment is only a description of the preferred implementation of the utility model, and is not a limitation to the scope of protection of the utility model. The various forms of deformation made should fall within the scope of protection determined by the claims of the present utility model.

Claims (5)

1. A precooling energy-saving dehumidification system, comprising a housing and a dehumidification unit arranged in the housing, characterized in that: the dehumidification unit is provided with a compressor (1), a water-cooled condenser (2), an air-cooled condenser (3), expansion valve (4), surface cooler (5) and air-gas plate heat exchanger (6); compressor (1), water-cooled condenser (2), expansion valve (4) and surface cooler (5 ) is provided with a first refrigerant circulation circuit, and a second refrigerant circulation circuit is provided between the compressor (1), the air-cooled condenser (3), the expansion valve (4) and the surface cooler (5) , the first refrigerant circulation loop and the second refrigerant circulation loop operate alternately in normal mode and energy-saving mode; a first cooling water circulation loop is provided between the water-cooled condenser (2) and the external cooling water system; the indoor air is sequentially The air dehumidification air duct is provided on the passage that flows through the air-air plate heat exchanger (6), the surface cooler (5), the air-air plate heat exchanger (6), and the air-cooled condenser (3) before being sent into the room. A blower fan is provided at the entrance of the air dehumidification duct. 2. A precooling energy-saving dehumidification system according to claim 1, characterized in that: the water-cooled condenser (2) is provided with a first refrigerant channel and a cooling water channel, and the air-cooled condenser (3) There is a second refrigerant channel in the center, and a third refrigerant channel in the surface cooler (5); the air-gas plate heat exchanger (6) is provided with a first air channel and a second air channel arranged crosswise ; The flow direction of the refrigerant is converted by setting a three-way regulating valve (7) between the first refrigerant circulation circuit and the second refrigerant circulation circuit; The first refrigerant circulation circuit is that the liquid outlet of the compressor (1) is connected to the liquid inlet of the three-way regulating valve (7) through a pipeline, and one liquid outlet of the three-way regulating valve (7) is connected through a pipeline The liquid inlet of the first refrigerant channel in the water-cooled condenser (2), the liquid outlet of the first refrigerant channel in the water-cooled condenser (2), is connected to the liquid inlet of the expansion valve (4) through a pipeline, and the expansion valve The liquid outlet of (4) is connected to the liquid inlet of the third refrigerant channel in the surface cooler (5) through a pipeline, and the liquid outlet of the third refrigerant channel in the surface cooler (5) is connected to the compressor through a pipeline (1) liquid inlet; The second refrigeration medium circulation circuit is that the liquid outlet of the compressor (1) is connected to the liquid inlet of the three-way regulating valve (7) through a pipeline, and the other liquid outlet of the three-way regulating valve (7) is connected through a pipeline Connect to the liquid inlet of the second refrigerant channel in the air-cooled condenser (3), and the liquid outlet of the second refrigerant channel in the air-cooled condenser (3) is connected to the liquid inlet of the expansion valve (4) through a pipeline , the liquid inlet of the expansion valve (4) is connected to the liquid inlet of the third refrigerant channel in the surface cooler (5) through a pipeline, and the liquid outlet of the third refrigerant channel in the surface cooler (5) is passed through a pipeline Connect the liquid inlet of compressor (1); The first cooling water circulation loop is that the liquid inlet and the liquid outlet of the cooling water channel in the water-cooled condenser (2) are respectively communicated with the external cooling water pipeline through pipelines to form a loop; The air dehumidification air channel is that indoor air flows through the first air channel in the air-gas plate heat exchanger (6), the surface cooler (5), and the second air channel in the air-air plate heat exchanger (6). channel, air-cooled condenser (3) and then sent to the indoor channel. 3. A precooling energy-saving dehumidification system according to claim 2, characterized in that: the liquid outlet of the first refrigerant channel in the water-cooled condenser (2) and the liquid inlet of the expansion valve (4) The first check valve (8) is arranged on the pipeline between them; the liquid outlet between the second refrigerant channel in the air-cooled condenser (3) and the liquid inlet connected to the expansion valve (4) A second one-way valve (9) is provided on the pipeline. 4. A precooling energy-saving dehumidification system according to claim 3, characterized in that: said air dehumidification air duct is also provided with a coil cooler (10) at the front end of the air-air plate heat exchanger (6), A second cooling water circulation loop is provided between the coil cooler (10) and the external cooling water system. 5. A pre-cooling energy-saving dehumidification system according to any one of claims 1-4, characterized in that it also includes an electrical control unit, which is used to control the power distribution and operating parameters of each component in the unit. control.