Double-cold-source fresh air dehumidification system

Abstract

The utility model relates to a double-cold-source fresh air dehumidification system which adopts two electric ball valves to replace a combination of a plurality of complex valves in related technologies, so that the system structure and the control logic are greatly simplified, the manufacturing cost and the control complexity of the system are effectively reduced, the hardware cost and the software development amount are reduced, and the system reliability is improved. The control strategy can be automatically switched according to the air inlet temperature, complex control program adjustment and shutdown restart are not needed, system faults caused by external condition changes such as cooling water supply interruption are effectively avoided, and stability and reliability are higher.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, and in particular to a dual-cold-source fresh air dehumidification system. Background Technology

[0002] Modern buildings have increasingly higher requirements for indoor air quality, leading to the widespread application of fresh air systems. Fresh air systems introduce fresh outdoor air, dilute indoor pollutants, and improve indoor air quality, creating a healthier and more comfortable living environment. However, simply introducing untreated outdoor air often fails to directly meet people's comfort needs. Especially during humid or dry seasons, directly introducing unconditioned outdoor air can cause significant fluctuations in indoor temperature and humidity, affecting human comfort and potentially even causing health problems.

[0003] To address these issues, dual-source fresh air dehumidification systems have emerged. These systems typically employ two cooling sources: cooling water and refrigerant (such as Freon). These are used to pre-cool and reheat the fresh air via plate heat exchangers and coil heat exchangers, respectively, thus achieving precise regulation of the fresh air's temperature and humidity. Specifically, the cooling water pre-cools the fresh air, reducing its temperature and humidity, thereby lessening the dehumidification burden on the refrigeration system; the refrigerant performs deep dehumidification and, if necessary, reheats the air to ensure that the air delivered into the room reaches the optimal temperature and humidity range.

[0004] However, to cope with complex operating conditions and achieve flexible switching between multiple modes, some existing dual-source fresh air dehumidification systems often require a large number of control valves, such as solenoid valves and expansion valves. These valves require complex control logic for coordination, which not only increases the control difficulty and implementation cost of the system, but also makes it difficult to guarantee the stability and reliability of the system under various operating conditions. Utility Model Content

[0005] To address the aforementioned issues, this application provides a dual-cold-source fresh air dehumidification system with a simplified system structure and control logic.

[0006] To achieve the above objectives, this application provides a dual-cold-source fresh air dehumidification system, including a compressor, a plate heat exchanger, an air duct, and a water supply pipe for connecting to an external cooling water source. A coil heat exchanger, an evaporator, a condenser, and a fan are sequentially arranged within the air duct. The inlet ends of both the plate heat exchanger and the coil heat exchanger are connected to an external cooling water source via the water supply pipe. One output end of the compressor is connected to the plate heat exchanger, and the other is connected to the condenser. The output ends of the condenser and the plate heat exchanger are both connected to the input end of the evaporator, and the output end of the evaporator is connected to the input end of the compressor. The system further includes:

[0007] A first electric ball valve is disposed between the output end of the compressor and the condenser, and is used to control the refrigerant flow to the condenser;

[0008] The second electric ball valve is located between the output end of the compressor and the plate heat exchanger, and is used to control the refrigerant flow to the plate heat exchanger.

[0009] The controller is electrically connected to the first electric ball valve and the second electric ball valve, and is used to control the opening degree and / or opening and closing state of the first electric ball valve and the second electric ball valve according to the inlet air temperature of the air duct.

[0010] Preferably, the controller is specifically used for:

[0011] When the air inlet temperature is lower than the first set temperature, the first electric ball valve is opened and the second electric ball valve is closed.

[0012] When the inlet air temperature is greater than the second set temperature, the first electric ball valve is closed and the second electric ball valve is opened.

[0013] When the inlet air temperature is between the first set temperature and the second set temperature, the first electric ball valve and the second electric ball valve are both opened, and the opening degree of the first electric ball valve and the second electric ball valve is adjusted according to the outlet air temperature of the air duct, wherein the sum of the opening degree of the first electric ball valve and the second electric ball valve is 100%.

[0014] Preferably, the system also includes a liquid storage tank and an electronic expansion valve. The output end of the condenser and the output end of the plate heat exchanger are both connected to the input end of the liquid storage tank, and the output end of the liquid storage tank is connected to the input end of the evaporator through the electronic expansion valve.

[0015] Preferably, a first check valve is provided on the pipeline between the output end of the plate heat exchanger and the input end of the liquid storage tank, and a second check valve is provided on the pipeline between the output end of the condenser and the input end of the liquid storage tank.

[0016] Preferably, temperature sensors are provided on both the air inlet and air outlet sides of the air duct, and the temperature sensors are electrically connected to the controller.

[0017] Preferably, both the coil heat exchanger and the plate heat exchanger are equipped with proportional regulating valves on their outlet pipes.

[0018] The dual-cold-source fresh air dehumidification system designed in this application greatly simplifies the system structure and control logic by using two electric ball valves instead of the combination of multiple complex valves in related technologies. This effectively reduces the system's manufacturing cost and control complexity, decreases hardware costs and software development workload, and enables automatic switching of control strategies based on the inlet air temperature. It eliminates the need for complex control program adjustments and shutdown restarts, effectively avoiding system failures caused by changes in external conditions such as cooling water supply interruptions, resulting in higher stability and reliability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the dual-cold-source fresh air dehumidification system provided in the embodiments of this application.

[0020] Figure 2 This is a flowchart of the dual-cold-source fresh air dehumidification control method provided in the embodiments of this application.

[0021] The components include: compressor 10, plate heat exchanger 20, air duct 30, coil heat exchanger 31, evaporator 32, condenser 33, fan 34, water supply pipe 40, first electric ball valve 50, second electric ball valve 60, liquid storage tank 70, electronic expansion valve 71, first check valve 80, second check valve 81, temperature sensor 90, and proportional regulating valve 100. Detailed Implementation

[0022] The preferred embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0023] In one aspect, this application provides a dual-source fresh air dehumidification system, mainly composed of a compressor 10, a plate heat exchanger 20, an air duct 30, and a water supply pipe 40. Inside the air duct 30, a coil heat exchanger 31, an evaporator 32, a condenser 33, and a fan 34 are arranged sequentially according to the airflow direction. The water inlets of both the plate heat exchanger 20 and the coil heat exchanger 31 are connected to an external cooling water source via the water supply pipe 40, so as to pre-cool the refrigerant or fresh air using cooling water. The output of the compressor 10 is divided into two paths: one path is connected to the refrigerant inlet of the plate heat exchanger 20 via a refrigerant pipeline, and the other path is connected to the refrigerant inlet of the condenser 33 via a refrigerant pipeline. The refrigerant, after heat exchange in the plate heat exchanger 20 and the condenser 33, collects at the input of the evaporator 32, and then returns to the input of the compressor 10 after heat exchange in the evaporator 32, forming a complete refrigerant circulation loop.

[0024] The key improvement of this embodiment lies in the precise control of the refrigerant flow through the condenser 33 and the plate heat exchanger 20 achieved by respectively installing a first electric ball valve 50 and a second electric ball valve 60 on the refrigerant pipeline. Specifically, the first electric ball valve 50 is located between the output end of the compressor 10 and the condenser 33 to control the refrigerant flow to the condenser 33; the second electric ball valve 60 is located between the output end of the compressor 10 and the plate heat exchanger 20 to control the refrigerant flow to the plate heat exchanger 20. Both the first electric ball valve 50 and the second electric ball valve 60 can be two-way electric ball valves. By respectively installing the first electric ball valve 50 and the second electric ball valve 60 on the corresponding pipelines, the refrigerant flow to the condenser 33 and the plate heat exchanger 20 can be controlled. The overall control components are few, and waterless dehumidification can be achieved, that is, operation in three modes: water-only refrigerant, refrigerant-only, and integrated water-refrigerant refrigerant. In this way, flexible control of refrigerant flow is achieved using only two electric ball valves, which greatly simplifies the system structure and control logic, reduces manufacturing costs, and improves system reliability.

[0025] Furthermore, the dual-source fresh air dehumidification system of this embodiment can flexibly switch between multiple operating modes by adjusting the opening of the first electric ball valve 50 and the second electric ball valve 60 to adapt to different working conditions:

[0026] Waterless mode: The system can still operate normally even when the water supply pipe 40 cannot provide cooling water. In this mode, the piping related to the coil heat exchanger 31 is not used, and the system uses only refrigerant (Freon) as the refrigerant. By properly adjusting the opening of the first electric ball valve 50 and the second electric ball valve 60, the heat dissipation capacity of the condenser 33 can be adjusted, thereby ensuring the normal operation of the compressor 10 and basic dehumidification effect.

[0027] Water-only cooling mode: When only cooling water is supplied and the compressor is not required for cooling, the compressor 10 can be stopped, and neither the evaporator 32 nor the condenser 33 is used. Cooling water flows in from the supply pipe 40, then passes through the coil heat exchanger 31 to cool the fresh air, and finally flows out from the drain pipe of the coil heat exchanger 31. This mode is suitable for applications where high air temperature is not required, but a certain degree of cooling and dehumidification is needed.

[0028] Water-refrigerant mode: When cooling water is available and strong dehumidification is required, both the first electric ball valve 50 and the second electric ball valve 60 are opened. Cooling water flows through the coil heat exchanger 31 to pre-cool the fresh air, while refrigerant flows through the plate heat exchanger 20 and the condenser 33 respectively to deeply dehumidify and regulate the temperature of the fresh air. This mode can fully utilize the advantages of cooling water and refrigerant to achieve efficient temperature and humidity control.

[0029] Furthermore, both the first electric ball valve 50 and the second electric ball valve 60 are electrically connected to the controller (not shown) provided in this embodiment, and are used to control the opening degree and / or opening / closing state of the first electric ball valve 50 and the second electric ball valve 60 according to the inlet air temperature of the air duct 30. In specific implementation, temperature sensors 90 are provided on both the inlet and outlet sides of the air duct 30, and the temperature sensors 90 are electrically connected to the controller. The controller then automatically adjusts the opening and closing of the first electric ball valve 50 and the second electric ball valve 60 and the opening degree based on these data and in conjunction with a preset control strategy, thereby achieving precise control of the refrigerant flow.

[0030] In this embodiment, the controller is specifically used for:

[0031] When the inlet air temperature is lower than the first set temperature (e.g., 18 degrees Celsius), the first electric ball valve 50 is opened and the second electric ball valve 60 is closed. At this time, all the refrigerant output by the compressor 10 flows to the condenser 33 to heat the air after it has been cooled and dehumidified by the evaporator 32, so as to increase the supply air temperature, prevent the indoor temperature from being too low, and ensure human comfort.

[0032] When the inlet air temperature exceeds the second set temperature (e.g., 35 degrees Celsius), the first electric ball valve 50 is closed, and the second electric ball valve 60 is opened. At this time, all the refrigerant output by the compressor 10 flows to the condenser 33 to heat the air that has been cooled and dehumidified by the evaporator 32, thereby increasing the supply air temperature. The second set temperature is set to be higher than the first set temperature.

[0033] When the inlet air temperature is between the first and second set temperatures, both the first electric ball valve 50 and the second electric ball valve 60 are opened. The opening degree of the first electric ball valve 50 and the second electric ball valve 60 is adjusted according to the outlet air temperature of the air duct 30 to achieve precise temperature and humidity control. Specifically, the user can set a target outlet air temperature according to their own needs. When the actual outlet air temperature is higher than the target outlet air temperature, the controller will reduce the opening degree of the first electric ball valve 50 and increase the opening degree of the second electric ball valve 60, thereby reducing the refrigerant flow through the condenser 33, reducing the heating amount, and lowering the supply air temperature. Conversely, when the actual outlet air temperature is lower than the target outlet air temperature, the controller will increase the opening degree of the first electric ball valve 50 and decrease the opening degree of the second electric ball valve 60, thereby increasing the refrigerant flow through the condenser 33, increasing the heating amount, and increasing the supply air temperature. During this process, the sum of the opening degrees of the first electric ball valve 50 and the second electric ball valve 60 is always kept at 100%.

[0034] By replacing the combination of multiple complex valves in related technologies with two two-way electric ball valves, the system structure and control logic are greatly simplified, thereby effectively reducing the system's manufacturing cost and control complexity, and decreasing hardware costs and software development workload. Simultaneously, the dual-source cold air dehumidification system in this embodiment can automatically switch control strategies based on the inlet air temperature, eliminating the need for complex control program adjustments and shutdown restarts. This effectively avoids system failures caused by changes in external conditions such as cooling water supply interruptions, resulting in higher stability and reliability, and providing users with a more comfortable and energy-efficient indoor environment.

[0035] In some embodiments, such as Figure 1 As shown, it also includes a liquid storage tank 70 and an electronic expansion valve 71. The output end of the condenser 33 and the output end of the plate heat exchanger 20 are both connected to the input end of the liquid storage tank 70. The output end of the liquid storage tank 70 is connected to the input end of the evaporator 32 through the electronic expansion valve 71. By setting up the liquid storage tank 70, on the one hand, the refrigerant from different pipelines can be fully mixed, making the temperature of the refrigerant entering the electronic expansion valve 71 more stable, thereby improving the control accuracy and service life of the electronic expansion valve 71 and ensuring the reliability of system operation. On the other hand, under certain operating conditions (for example, when only cooling water is used for refrigeration), it may be necessary to shut off the refrigerant pipeline flowing through the plate heat exchanger 20, so that all the refrigerant flows to the condenser 33. At this time, if the refrigerant cannot be vented smoothly, liquid accumulation may occur in the refrigerant pipeline after the plate heat exchanger 20, especially inside the reheat coil. Therefore, by setting up the liquid storage tank 70, the refrigerant remaining in the refrigerant pipeline after the plate heat exchanger 20 can be stored, thereby effectively avoiding the liquid accumulation phenomenon in the reheat coil and ensuring the stable operation of the system.

[0036] In some embodiments, such as Figure 1 As shown, a first check valve 80 is installed on the pipeline between the output end of the plate heat exchanger 20 and the input end of the liquid storage tank 70, and a second check valve 81 is installed on the pipeline between the output end of the condenser 33 and the input end of the liquid storage tank 70. By setting the first check valve 80 and the second check valve 81, the backflow of refrigerant caused by fluctuations in the refrigerant outlet pressure of the plate heat exchanger 20 and the condenser 33 due to changes in operating conditions is prevented, ensuring that the refrigerant always flows in the predetermined direction and guaranteeing the stability and reliability of the system operation.

[0037] In some embodiments, such as Figure 1 As shown, both the coil heat exchanger 31 and the plate heat exchanger 20 are equipped with proportional regulating valves 100 on their outlet pipes. By setting the proportional regulating valves 100, precise control of the cooling water flow rate is achieved, thereby allowing for more flexible adjustment of the pre-cooling effect of the fresh air and the temperature of the refrigerant. Ultimately, this improves the system's temperature and humidity control accuracy and energy efficiency, bringing users a more comfortable and energy-saving indoor environment experience.

[0038] Secondly, embodiments of this application provide a dual-cold-source fresh air dehumidification control method, applicable to the dual-cold-source fresh air dehumidification system of any embodiment of the first aspect, such as... Figure 2 As shown, the method includes:

[0039] S1. Detect the inlet air temperature of air duct 30;

[0040] S2. In response to the inlet air temperature, the opening degree and / or opening / closing state of the first electric ball valve 50 and the second electric ball valve 60 are adjusted by the controller to control the refrigerant flow through the plate heat exchanger 20 and the condenser 33.

[0041] In step S2, the specific control process is as follows:

[0042] S21. When the inlet air temperature is lower than the first set temperature, control the first electric ball valve 50 to open and the second electric ball valve 60 to close, so that all the refrigerant flows through the condenser 33 for heating and dehumidification; at this time, all the refrigerant output by the compressor 10 flows to the condenser 33 to heat the air after it has been cooled and dehumidified by the evaporator 32, so as to increase the supply air temperature and prevent the indoor temperature from being too low.

[0043] S22. When the inlet air temperature is higher than the second set temperature, the first electric ball valve 50 is closed and the second electric ball valve 60 is opened, allowing all the refrigerant to flow through the plate heat exchanger 20 for cooling and dehumidification. At this time, all the refrigerant output from the compressor 10 flows to the plate heat exchanger 20 to exchange heat with the cooling water, reducing the refrigerant temperature and thus improving the dehumidification capacity of the evaporator 32 and reducing the supply air temperature. The second set temperature is set to be higher than the first set temperature; specifically, the first set temperature can be set to 18 degrees Celsius and the second set temperature can be set to 35 degrees Celsius.

[0044] S23. When the inlet air temperature is between the first set temperature and the second set temperature, the first electric ball valve 50 and the second electric ball valve 60 are both opened, and the opening degree of the first electric ball valve 50 and the second electric ball valve 60 is adjusted according to the outlet air temperature of the air duct 30, wherein the sum of the opening degree of the first electric ball valve 50 and the second electric ball valve 60 is 100%.

[0045] For example, in spring and autumn, the detected inlet air temperature is 25 degrees Celsius, which is between the first set temperature of 18 degrees Celsius and the second set temperature of 35 degrees Celsius. At this time, the controller will simultaneously control the first electric ball valve 50 and the second electric ball valve 60 to open. The specific opening ratio will be determined based on the outlet air temperature collected by the temperature sensor 90 at the outlet of the air duct 30.

[0046] Suppose the user sets a target outlet air temperature of 22 degrees Celsius, while the actual outlet air temperature is 24 degrees Celsius. In this case, the controller will decrease the opening of the first electric ball valve 50, for example, from 50% to 40%, while simultaneously increasing the opening of the second electric ball valve 60, for example, from 50% to 60%. This reduces the refrigerant flow through the condenser 33, decreasing the heating output, while increasing the refrigerant flow through the plate heat exchanger 20, increasing the cooling output, ultimately lowering the supply air temperature and gradually approaching the target outlet air temperature of 22 degrees Celsius. Conversely, suppose the user sets a target outlet air temperature of 22 degrees Celsius, while the actual outlet air temperature is 20 degrees Celsius. In this case, the controller will increase the opening of the first electric ball valve 50 and decrease the opening of the second electric ball valve 60, thereby increasing the supply air temperature and gradually approaching the target outlet air temperature of 22 degrees Celsius. For example, during humid weather or the plum rain season, when the outlet air temperature is lower, the opening of the first electric ball valve can be set to 90%, and the opening of the second electric ball valve can be set to 10%.

[0047] Through the above control process, this embodiment can dynamically adjust the opening degree of the first electric ball valve 50 and the second electric ball valve 60 according to the inlet air temperature of the air duct 30, so as to achieve precise control of the refrigerant flow through the plate heat exchanger 20 and the condenser 33, thereby ensuring the stability and comfort of the outlet air temperature.

[0048] The dual-cold-source fresh air dehumidification system provided in this embodiment greatly simplifies the system structure and control logic by using two electric ball valves instead of the combination of multiple complex valves in related technologies. This effectively reduces the system's manufacturing cost and control complexity, decreases hardware costs and software development workload, and enables automatic switching of control strategies based on the inlet air temperature. It eliminates the need for complex control program adjustments and shutdown restarts, effectively avoiding system failures caused by changes in external conditions such as cooling water supply interruptions, resulting in higher stability and reliability.

[0049] In the description of this application, it should be noted that the terms "vertical", "up", "down", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0050] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0051] Finally, it should be noted that the above descriptions are merely preferred embodiments of this application and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A dual cold source fresh air dehumidification system, comprising a compressor, a plate heat exchanger, an air duct and a water supply pipe for connecting an external cooling water source, wherein a coil heat exchanger, an evaporator, a condenser and a fan are sequentially arranged in the air duct; the water inlet ends of the plate heat exchanger and the coil heat exchanger are connected to the external cooling water source through the water supply pipe; the output end of the compressor is connected to the plate heat exchanger in one way and to the condenser in another way; the output ends of the condenser and the plate heat exchanger are connected to the input end of the evaporator, and the output end of the evaporator is connected to the input end of the compressor, characterized in that, Also comprising: a first electric ball valve arranged between the output end of the compressor and the condenser for controlling the refrigerant flow to the condenser; a second electric ball valve arranged between the output end of the compressor and the plate heat exchanger for controlling the refrigerant flow to the plate heat exchanger; a controller electrically connected with the first electric ball valve and the second electric ball valve for controlling the opening degree and / or on-off state of the first electric ball valve and the second electric ball valve according to the inlet air temperature of the air duct.

2. The dual cold source outdoor air dehumidification system of claim 1, wherein, The controller is specifically used for: controlling the first electric ball valve to open and the second electric ball valve to close when the inlet air temperature is less than a first set temperature; controlling the first electric ball valve to close and the second electric ball valve to open when the inlet air temperature is greater than a second set temperature; controlling the first electric ball valve and the second electric ball valve to both open and adjusting the opening degree of the first electric ball valve and the second electric ball valve according to the outlet air temperature of the air duct when the inlet air temperature is between the first set temperature and the second set temperature, wherein the sum of the opening degree of the first electric ball valve and the second electric ball valve is 100%.

3. The dual cold source outdoor air dehumidification system of claim 1, wherein, Further comprising a liquid storage tank and an electronic expansion valve, the output end of the condenser and the output end of the plate heat exchanger are both connected to the input end of the liquid storage tank, and the output end of the liquid storage tank is connected to the input end of the evaporator through the electronic expansion valve.

4. The dual cold source outdoor air dehumidification system of claim 3, wherein, A first one-way valve is arranged on the pipeline between the output end of the plate heat exchanger and the input end of the liquid storage tank, and a second one-way valve is arranged on the pipeline between the output end of the condenser and the input end of the liquid storage tank.

5. The dual cold source outdoor air dehumidification system of claim 1, wherein, Temperature sensors are arranged on the inlet air side and the outlet air side of the air duct, and the temperature sensors are electrically connected with the controller.

6. The dual cold source outdoor air dehumidification system of claim 1, wherein, Proportional regulating valves are arranged on the water outlet pipes of the coil heat exchanger and the plate heat exchanger.

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