A centralized air conditioning system with independently installed supply and exhaust fans and variable fresh air function.

Abstract

This utility model relates to the field of air conditioning system technology, aiming to solve the problems of existing technologies having limited functionality and failing to maximize energy saving and reduce operating costs. It provides a centralized air conditioning system with independently installed supply and exhaust fans and a variable fresh air function, including an electrical control box, fresh air ducts, supply air ducts, return air ducts, and exhaust air ducts. Each of the fresh air ducts, supply air ducts, return air ducts, and exhaust air ducts has a fresh air valve, a combined air handling unit, a supply air valve, a return air valve, and an exhaust air valve, all electrically connected to the electrical control box. A room exists between the outlet of the supply air duct and the inlet of the return air duct. Temperature and humidity sensors electrically connected to the electrical control box are present on the fresh air duct, supply air duct, room, and return air duct. The combined air handling unit includes a differential pressure switch, an electrically operated two-way regulating valve, a solenoid valve, a supply fan, and a pressure transmitter electrically connected to the electrical control box. The beneficial effects of this utility model are its diverse functions, maximizing energy savings and reducing operating costs.

Description

Technical Field

[0001] This utility model relates to the field of air conditioning system technology, and more specifically, to a centralized air conditioning system with independently set supply and exhaust fans and a fresh air conversion function. Background Technology

[0002] In the practical application of centralized air conditioning system engineering, single-fan (only supply fan) single-return air system is a common choice. The significant feature of this type of system is that it operates with a fixed fresh air ratio throughout the year. This operating mode has obvious limitations, as it cannot utilize fresh air as a natural cold source, thus making it difficult to effectively reduce the energy consumption of the chiller.

[0003] In recent years, some design technologies have addressed the exhaust challenges of single-fan systems operating with 100% fresh air during transitional seasons, and have solved these challenges by adding exhaust fans. However, this improvement has not yet enabled centralized air conditioning systems to achieve optimal energy conservation and reduced operating costs.

[0004] The core problem is that the fixed fresh air ratio operation mode is difficult to adapt to the dynamic load demand under the climate change throughout the year. In the transition season, when the outdoor air enthalpy is lower than the indoor air enthalpy, the cooling unit’s operating time can be reduced by increasing the fresh air volume or even using 100% fresh air operation. However, the structural limitations of the single-fan system make it impossible to flexibly adjust the fresh air ratio. Even if an exhaust fan is added to solve the exhaust problem of 100% fresh air operation, the lack of a precise fresh air volume control mechanism and intelligent linkage control strategy will still lead to energy waste. Either the natural cooling source is not fully utilized due to insufficient fresh air volume, or the subsequent processing energy consumption is increased due to excessive fresh air volume. In the end, it is difficult to maximize the reduction of the overall system energy consumption, and the improvement of operating economy is limited. This design defect not only restricts the energy utilization efficiency of the air conditioning system, but also is not compatible with the current development trend of green building and energy conservation and emission reduction. Utility Model Content

[0005] The present invention aims to provide a centralized air conditioning system with independently set supply and exhaust fans and a fresh air conversion function, in order to solve the problem that the existing technology has relatively simple functions and cannot maximize energy saving and reduce operating costs of centralized air conditioning systems.

[0006] The embodiments of this utility model are implemented as follows:

[0007] This utility model embodiment provides a centralized air conditioning system with independently set supply and exhaust fans and variable fresh air function, which includes an electrical control box, a fresh air duct, a supply air duct, a return air duct and an exhaust air duct;

[0008] The aforementioned fresh air duct is connected to the aforementioned return air duct, one end of the aforementioned supply air duct is connected to the connection point of the aforementioned fresh air duct and the aforementioned return air duct, the aforementioned exhaust duct is connected to the aforementioned return air duct, and the exhaust port of the aforementioned exhaust duct is connected to an exhaust fan.

[0009] The aforementioned fresh air duct, the aforementioned supply air duct, the aforementioned return air duct and the aforementioned exhaust air duct are respectively equipped with a fresh air valve, a combined air handling unit, a supply air valve, a return air valve and an exhaust air valve, and the aforementioned fresh air valve, the aforementioned supply air valve, the aforementioned return air valve and the aforementioned exhaust air valve are all electrically connected to the aforementioned electrical control box.

[0010] There is a room between the outlet of the aforementioned air supply duct and the inlet of the aforementioned return air duct. Temperature and humidity sensors that are electrically connected to the aforementioned control box are installed on the aforementioned fresh air duct, the aforementioned air supply duct, the aforementioned room, and the aforementioned return air duct.

[0011] The aforementioned combined air handling unit includes a differential pressure switch, an electrically operated two-way regulating valve, a solenoid valve, a blower, and a pressure transmitter that are electrically connected to the aforementioned electrical control box.

[0012] In this solution, firstly, the aforementioned electrical control box can detect the temperature and humidity of the air in the aforementioned fresh air duct, the aforementioned supply air duct, the aforementioned return air duct, the aforementioned room, and the aforementioned exhaust air duct based on the aforementioned temperature and humidity sensors. Then, according to seasonal changes, it controls the aforementioned fresh air valve, the aforementioned combined air handling unit, the aforementioned supply air valve, the aforementioned return air valve, the aforementioned exhaust air valve, the aforementioned differential pressure switch, the aforementioned electric two-way regulating valve, the aforementioned solenoid valve, the aforementioned supply fan, the aforementioned pressure transmitter, and the aforementioned exhaust fan to automatically adjust the fresh, return, and exhaust air ratio, thereby adjusting the cooling and heating output and air volume output, so that the system can achieve the ideal operating effect.

[0013] The centralized air conditioning system disclosed in this implementation plan, which has independently set supply and exhaust fans and has a variable fresh air function, can adjust the cooling and heating output and air volume of the system to achieve energy saving. Through this energy-saving operation scheme and automatic control technology, the system can achieve ideal operating results. Thus, a centralized air conditioning system with independently set supply and exhaust fans and a variable fresh air function has multiple functions and can maximize the energy saving and reduce operating costs of the centralized air conditioning system.

[0014] Optionally: The air inlet of the above-mentioned combined air handling unit is equipped with a primary and secondary filter, and the differential pressure switch is electrically connected to both sides of the primary and secondary filter.

[0015] With this configuration, the aforementioned primary and secondary filters can filter particulate matter in the air, protect the post-filter, extend the service life of the post-filter, reduce equipment maintenance, improve air purification effect, effectively reduce air pollution, and protect air conditioning hardware. The differential pressure switch is used to detect the clogging status of the aforementioned primary and secondary filters.

[0016] Optionally: The primary and secondary filters are provided with a surface cooler heater on the side near the air supply valve. The surface cooler heater is fixed inside the combined air handling unit. The surface cooler heater is connected to a hot and cold water pipe. The electric two-way regulating valve is installed on the hot and cold water pipe.

[0017] With this configuration, the hot and cold water in the hot and cold water pipes connected to the surface cooler heater can be switched via the electric two-way regulating valve, facilitating the regulation of air temperature and humidity. The surface cooler heater can switch modes as needed, functioning as a surface cooler to cool and dehumidify the air, or as a heater to heat the air. This allows the system to adapt to different operating conditions, ensuring that the system operates in an energy-efficient and high-performance state, maximizing energy savings and reducing operating costs.

[0018] Optionally: A humidifier is provided on the side of the surface cooler heater near the air supply valve. The humidifier is fixed inside the combined air handling unit. A humidifying water pipe is connected to the humidifier. The solenoid valve is installed on the humidifying water pipe.

[0019] With this setup, the humidifier connected to the humidifying water pipe is controlled by the solenoid valve to change the humidity of the air supplied to the combined air handling unit, making it easier for people to breathe, protecting their respiratory tract, and making the air in the room more breathable. The opening and closing size of the solenoid valve can be adjusted according to the season and working conditions to control the humidity of the air in the room.

[0020] Optionally: The aforementioned blower is located inside the aforementioned combined air handling unit, and the aforementioned pressure transmitter is electrically connected to both ends of the aforementioned blower.

[0021] With this configuration, the aforementioned blower can increase the air velocity in the aforementioned air supply duct, facilitating rapid entry into the aforementioned room. The aforementioned pressure transmitter can detect the pressure difference between the air before and after the aforementioned blower, allowing the system to easily adjust the system's heating / cooling capacity and air volume output, enabling the system to achieve ideal operating results.

[0022] Optionally, the hot and cold water pipes and the humidifying water pipes are connected to the surface cooling heater and the humidifier respectively via a first flexible joint and a second flexible joint.

[0023] This configuration, using the aforementioned first flexible joint and the aforementioned second flexible joint, helps to improve the shock absorption effect at the connection between the aforementioned hot and cold water pipes and the aforementioned humidifying water pipe, making it more adaptable to the elongation and contraction of the pipes, and providing a certain degree of compensation for thermal expansion and contraction caused by temperature changes.

[0024] Optionally, butterfly valves are installed on both the hot and cold water pipes and the humidifying water pipes mentioned above.

[0025] With this configuration, the butterfly valve can open and close the hot and cold water pipes and the humidifying water pipe, thereby facilitating the inspection and maintenance of the air conditioning system. At the same time, it prevents liquid leakage caused by damage to the surface cooler and the humidifier.

[0026] Optionally: A first temperature and humidity sensor is installed on the fresh air duct. The first temperature and humidity sensor is located on the side of the fresh air valve near the air inlet of the fresh air duct. The first temperature and humidity sensor is electrically connected to the electrical control box via a first signal line.

[0027] A second temperature and humidity sensor is installed on the aforementioned air supply duct. The second temperature and humidity sensor is located on the aforementioned air supply duct between the aforementioned combined air handling unit and the aforementioned air supply valve. The second temperature and humidity sensor is electrically connected to the aforementioned electrical control box via a second signal line.

[0028] A third temperature and humidity sensor is installed inside the room, and the third temperature and humidity sensor is electrically connected to the electrical control box via a third signal line.

[0029] A fourth temperature and humidity sensor is installed on the aforementioned return air duct. The fourth temperature and humidity sensor is located on the aforementioned return air duct between the aforementioned return air valve and the aforementioned exhaust air duct. The fourth temperature and humidity sensor is electrically connected to the aforementioned electrical control box via a fourth signal line.

[0030] With this setup, the temperature and humidity of the air in the fresh air duct, the supply air duct, the room, and the return air duct are detected by the first, second, third, and fourth temperature and humidity sensors. The detected signals are transmitted to the electrical control box, which allows the system to automatically adjust the ratio of fresh air, return air, and exhaust air, thus meeting the needs of summer cooling, winter heating, and fresh air during transitional seasons.

[0031] Optionally, the aforementioned blower is electrically connected to the aforementioned electrical control box via a fifth signal line, and the aforementioned fifth signal line is electrically connected to a first distribution box.

[0032] This setup allows for independent control of the aforementioned air supply fan, which in turn controls the airflow output of the aforementioned air supply duct, enabling rapid air exchange within the room.

[0033] Optionally: The exhaust fan is electrically connected to the electrical control box via the sixth signal line, and the sixth signal line is electrically connected to the second distribution box.

[0034] With this setup, the exhaust fan can be controlled by the electrical control box to adjust the exhaust volume, which helps to increase the speed of air exchange in the room and maximizes energy savings and reduces operating costs for the central air conditioning system.

[0035] Optionally: the exhaust duct is connected to an exhaust box, the exhaust fan is installed inside the exhaust box, and the end of the exhaust box away from the exhaust duct has an exhaust outlet.

[0036] With this configuration, the exhaust box can easily collect the air that needs to be exhausted from the room, and the exhaust fan can easily discharge the air inside the exhaust box from the exhaust outlet, which helps to regulate the temperature and humidity in the room according to the operating conditions.

[0037] In summary, the centralized air conditioning system disclosed in this utility model, which has independently set supply and exhaust fans and has a variable fresh air function, has multiple functions and can maximize energy saving and reduce operating costs. Attached Figure Description

[0038] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is an electrical control schematic diagram of a centralized air conditioning system with independently installed supply and exhaust fans and variable fresh air function, as described in an embodiment of this utility model.

[0040] Figure 2 This is an embodiment of the present utility model. Figure 1 Enlarged diagram of point A in the middle.

[0041] Icons: 1-Electrical control box, 2-Fresh air duct, 3-Supply air duct, 4-Return air duct, 5-Exhaust air duct, 6-Exhaust fan, 7-Fresh air valve, 8-Combined air handling unit, 9-Supply air valve, 10-Return air valve, 11-Exhaust air valve, 12-Room, 13-Temperature and humidity sensor, 14-Differential pressure switch, 15-Electric two-way regulating valve, 16-Solenoid valve, 17-Supply air fan, 18-Pressure transmitter, 19-Primary and medium-efficiency filters, 20-Surface cooler heater, 21-Hot and cold water pipes, 22-Humidifier 23-Humidifying water pipe, 24-First flexible connector, 25-Second flexible connector, 26-Butterfly valve, 27-First temperature and humidity sensor, 28-First signal line, 29-Second temperature and humidity sensor, 30-Second signal line, 31-Third temperature and humidity sensor, 32-Third signal line, 33-Fourth temperature and humidity sensor, 34-Fourth signal line, 35-Fifth signal line, 36-First distribution box, 37-Sixth signal line, 38-Second distribution box, 39-Exhaust box, 40-Exhaust outlet. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0043] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0044] Example

[0045] See Figure 1 and Figure 2 This embodiment proposes a centralized air conditioning system with independently set supply and exhaust fans and variable fresh air function, including an electrical control box 1, a fresh air duct 2, a supply air duct 3, a return air duct 4, and an exhaust air duct 5;

[0046] Fresh air duct 2 is connected to return air duct 4. One end of supply air duct 3 is connected to the connection between fresh air duct 2 and return air duct 4. Exhaust air duct 5 is connected to return air duct 4. Exhaust air duct 5 is connected to exhaust fan 6 at its exhaust port.

[0047] Fresh air duct 2, supply air duct 3, return air duct 4 and exhaust air duct 5 are respectively equipped with fresh air valve 7, combined air handling unit 8, supply air valve 9, return air valve 10 and exhaust air valve 11. Fresh air valve 7, supply air valve 9, return air valve 10 and exhaust air valve 11 are all electrically connected to electrical control box 1.

[0048] There is a room 12 between the outlet of the supply air duct 3 and the inlet of the return air duct 4. Temperature and humidity sensors 13 that are electrically connected to the control box 1 are installed on the fresh air duct 2, supply air duct 3, room 12 and return air duct 4.

[0049] The combined air handling unit 8 has a differential pressure switch 14, an electric two-way regulating valve 15, a solenoid valve 16, a blower 17, and a pressure transmitter 18 that are electrically connected to the control box 1.

[0050] In this solution, firstly, the electrical control box 1 can detect the temperature and humidity of the air in the fresh air duct 2, supply air duct 3, return air duct 4, room 12, and exhaust air duct 5 based on the temperature and humidity sensor 13. Then, according to seasonal changes, it controls the fresh air valve 7, combined air handling unit 8, supply air valve 9, return air valve 10, exhaust air valve 11, differential pressure switch 14, electric two-way regulating valve 15, solenoid valve 16, supply fan 17, pressure transmitter 18, and exhaust fan 6 to automatically adjust the fresh, return, and exhaust air ratio, thereby adjusting the cooling and heating output and air volume output, so that the system can achieve the ideal operating effect.

[0051] The centralized air conditioning system disclosed in this implementation plan, which has independently set supply and exhaust fans and has a variable fresh air function, can adjust the cooling and heating output and air volume of the system to achieve energy saving. Through this energy-saving operation scheme and automatic control technology, the system can achieve ideal operating results. Thus, a centralized air conditioning system with independently set supply and exhaust fans and a variable fresh air function has multiple functions and can maximize the energy saving and reduce operating costs of the centralized air conditioning system.

[0052] See Figure 1 and Figure 2 The air inlet of the combined air handling unit 8 is equipped with a primary and secondary filter 19. A differential pressure switch 14 is electrically connected to both sides of the primary and secondary filter 19. The primary and secondary filter 19 can filter particulate matter in the air, protect the post-filter, extend the service life of the post-filter, reduce equipment maintenance, improve air purification effect, effectively reduce air pollution, and protect air conditioning hardware. The differential pressure switch 14 is used to detect the blockage of the primary and secondary filter 19.

[0053] A surface cooler heater 20 is installed on the side of the primary and secondary efficiency filter 19 near the air supply valve 9. The surface cooler heater 20 is fixed inside the combined air handling unit 8. The surface cooler heater 20 is connected to a hot and cold water pipe 21. An electric two-way regulating valve 15 is installed on the hot and cold water pipe 21. The hot and cold water in the hot and cold water pipe 21 connected to the surface cooler heater 20 is switched by the electric two-way regulating valve 15, which facilitates the regulation of air temperature and humidity. The surface cooler heater 20 can switch modes as needed. It can be used as a surface cooler to achieve air cooling and dehumidification, or as a heater to achieve air heating. This allows the system to be adaptively adjusted according to different operating conditions, ensuring that the system is in an energy-efficient and high-performance operating state, saving energy and reducing operating costs to the greatest extent.

[0054] A humidifier 22 is provided on the side of the surface cooler heater 20 near the air supply valve 9. The humidifier 22 is fixed inside the combined air handling unit 8. The humidifier 22 is connected to a humidifying water pipe 23. A solenoid valve 16 is installed on the humidifying water pipe 23. The solenoid valve 16 controls the humidifier 22 connected to the humidifying water pipe 23 to change the humidity of the air supplied in the combined air handling unit 8, making it easier for people to breathe and protecting their respiratory tract. The air in the room 12 is conducive to people's breathing. The opening and closing size of the solenoid valve 16 can be adjusted according to the season and working conditions to control the humidity of the air in the room 12.

[0055] The blower 17 is located inside the combined air handling unit 8. The pressure transmitter 18 is electrically connected to both ends of the blower 17. The blower 17 can increase the air velocity in the air supply duct 3, so that the air can quickly enter the room 12. The pressure transmitter 18 can detect the pressure difference of the air before and after the blower 17, so that the system can adjust the cooling and heating and air volume output of the system, so that the system can achieve the ideal operating effect.

[0056] See Figure 1 and Figure 2 The hot and cold water pipes 21 and the humidifying water pipe 23 are connected to the surface cooling heater 20 and the humidifier 22 respectively through the first flexible joint 24 and the second flexible joint 25. The use of the first flexible joint 24 and the second flexible joint 25 helps to improve the shock absorption effect at the connection between the hot and cold water pipes 21 and the humidifying water pipe 23, and is more adaptable to the elongation and contraction of the pipes, and plays a certain role in compensating for thermal expansion and contraction caused by temperature changes.

[0057] Butterfly valves 26 are installed on both the hot and cold water pipes 21 and the humidifying water pipe 23. The butterfly valves 26 can open and close the hot and cold water pipes 21 and the humidifying water pipe 23, which facilitates the inspection and maintenance of the air conditioning system. At the same time, it prevents liquid leakage caused by damage to the surface cooler heater 20 and the humidifier 22.

[0058] See Figure 1 and Figure 2 A first temperature and humidity sensor 27 is installed on the fresh air duct 2. The first temperature and humidity sensor 27 is located on the side of the fresh air valve 7 near the air inlet of the fresh air duct 2. The first temperature and humidity sensor 27 is electrically connected to the electrical control box 1 through the first signal line 28.

[0059] A second temperature and humidity sensor 29 is installed on the air supply duct 3. The second temperature and humidity sensor 29 is located on the air supply duct 3 between the combined air handling unit 8 and the air supply valve 9. The second temperature and humidity sensor 29 is electrically connected to the electrical control box 1 through the second signal line 30.

[0060] A third temperature and humidity sensor 31 is installed inside room 12. The third temperature and humidity sensor 31 is electrically connected to the electrical control box 1 via a third signal line 32.

[0061] A fourth temperature and humidity sensor 33 is installed on the return air duct 4. The fourth temperature and humidity sensor 33 is located on the return air duct 4 between the return air valve 10 and the exhaust air duct 5. The fourth temperature and humidity sensor 33 is electrically connected to the electrical control box 1 through the fourth signal line 34. The temperature and humidity of the air in the fresh air duct 2, the supply air duct 3, the room 12 and the return air duct 4 are detected by the first temperature and humidity sensor 27, the second temperature and humidity sensor 29, the third temperature and humidity sensor 31 and the fourth temperature and humidity sensor 33. The detected signals are transmitted to the electrical control box 1, so that the system can automatically adjust the fresh air, return air and exhaust air ratio, which can meet the needs of summer cooling, winter heating and transition season fresh air.

[0062] The blower 17 is electrically connected to the control box 1 via the fifth signal line 35. The first distribution box 36 is electrically connected to the fifth signal line 35, which facilitates independent control of the blower 17 and thus controls the air volume output of the air supply duct 3, so that the air in the room 12 can be quickly replaced.

[0063] See Figure 1 and Figure 2 The exhaust fan 6 is electrically connected to the electrical control box 1 via the sixth signal line 37. The second distribution box 38 is electrically connected to the sixth signal line 37. The exhaust fan 6 can control the exhaust volume through the electrical control box 1, which helps to increase the speed of air replacement in the room 12 and enable the central air conditioning system to save energy and reduce operating costs to the greatest extent.

[0064] The exhaust duct 5 is connected to the exhaust box 39, and the exhaust fan 6 is installed inside the exhaust box 39. The end of the exhaust box 39 away from the exhaust duct 5 has an exhaust outlet 40. The exhaust box 39 is convenient for collecting the air that needs to be exhausted from the room 12, and the exhaust fan 6 can easily exhaust the air inside the exhaust box 39 from the exhaust outlet 40, which helps to regulate the temperature and humidity in the room 12 according to the operating conditions.

[0065] See Figure 1 and Figure 2 In this embodiment, the centralized air conditioning system with independently set supply and exhaust fans and variable fresh air function includes an air supply system, an exhaust system, a water system, and an automatic control system.

[0066] The air supply system adopts a combined air handling unit 8, which includes a fresh air section, a primary and secondary filter 19, a surface cooler heater 20, a humidifier 22, and a supply fan 17. The supply air duct 3, the fresh air duct 2, and the return air duct 4 are equipped with a supply air valve 9, a fresh air valve 7, a return air valve 10, and a temperature and humidity sensor 13, respectively. The supply air fan is a variable frequency fan.

[0067] The exhaust system uses an exhaust box 39, an exhaust valve 11 on the exhaust pipe 5, and an exhaust fan 6 is a variable frequency fan.

[0068] The water system consists of a surface-cooled heater 20 connected to hot and cold water pipes 21 via flexible joints, and a humidifier 22 connected to humidifying water pipes 23 via flexible joints. The hot and cold water pipes 21 are equipped with an electric two-way regulating valve 15, and the domestic water pipes are equipped with a solenoid valve 16.

[0069] The automatic control system uses an electrical control box 1. The system includes a first temperature and humidity sensor 27, a second temperature and humidity sensor 29, a third temperature and humidity sensor 31, a fourth temperature and humidity sensor 33, a pressure transmitter 18, and a differential pressure switch 14. The automatic control system has automatic and manual switching functions, and has remote and local control functions. It can automatically detect the temperature and humidity of the supply and return air and fresh air, as well as the temperature and humidity of the room 12 that needs to be monitored; it can automatically detect the operating status of the supply fan 17 and the differential pressure of the filter; and it can automatically adjust the surface cooler heater 20 and the electric two-way regulating valve according to the controlled parameters and set values. The solenoid valve 16 of the humidifier 22 can be automatically opened or closed when the opening degree of valve 15 is adjusted; it can automatically detect the temperature and humidity of the outdoor fresh air and automatically adjust the valve opening degree of the fresh air valve 7, supply air valve 9, exhaust air valve 11 and return air valve 10 according to the enthalpy value of the outdoor fresh air, and automatically adjust the air volume ratio between them; it can automatically control the start and stop of the combined air handling unit 8 and the exhaust fan 6; it can display the monitored data; it can provide fault alarms for fan failures and excessive filter differential pressure; it can use frequency conversion regulation for the supply fan 17 and the exhaust fan 6; and it can modify the set value of the controlled parameters.

[0070] See Figure 1 and Figure 2 In this embodiment, the centralized air conditioning system has five operating conditions:

[0071] Condition 1: Exhaust box 39 is closed, only combined air handling unit 8 is running, fresh air valve 7 is fixed at 10% opening, return air valve 10 is fixed at 90% opening, exhaust valve 11 is closed, and supply air valve 9 is fully open; hot and cold water pipe 21 is connected to cold water, and electric two-way regulating valve 15 is fully open; solenoid valve 16 of humidifying water pipe 23 is closed. This control is supplying cold air to room 12. This condition is the summer cooling condition.

[0072] Condition 2: Exhaust box 39 is closed, only combined air handling unit 8 is running, fresh air valve 7 is fixed at 10% opening, return air valve 10 is fixed at 90% opening, exhaust valve 11 is closed, and supply air valve 9 is fully open; hot and cold water pipe 21 is connected to hot water, electric two-way regulating valve 15 is fully open; solenoid valve 16 of humidifying water pipe 23 is open. This control is to send hot air to room 12. This condition is the winter heating condition.

[0073] Condition 3: Exhaust box 39 and combined air handling unit 8 are in operation. Fresh air valve 7 is fully open, return air valve 10 is fully closed, exhaust valve 11 is fully open, and supply air valve 9 is fully open. Electric two-way regulating valve 15 of hot and cold water pipe 21 is fully closed. Solenoid valve 16 of humidifying water pipe 23 is closed. This control is supplying air to room 12. This condition is the fresh air operation condition during the transition season.

[0074] In operating condition 4, the exhaust fan 39 and the combined air handling unit 8 are in operation. According to the enthalpy value of the outdoor fresh air, the fresh air valve 7, the return air valve 10, the exhaust air valve 11, and the supply air valve 9 are opened proportionally. The hot and cold water pipe 21 is connected to cold water, and the electric two-way regulating valve 15 is opened proportionally. The solenoid valve 16 of the humidifying water pipe 23 is closed. This control is to send cold air to the room 12. This operating condition is the fresh air operation condition when the summer temperature is not too high.

[0075] In operating condition 5, the exhaust fan 39 and the combined air handling unit 8 are in operation. According to the enthalpy value of the outdoor fresh air, the fresh air valve 7, the return air valve 10, the exhaust air valve 11, and the supply air valve 9 are opened proportionally. The hot and cold water pipe 21 is connected to hot water, and the electric two-way regulating valve 15 is opened proportionally. The solenoid valve 16 of the humidifying water pipe 23 is opened. This control is to send hot air to the room 12. This operating condition is the fresh air operation condition when the temperature is not too low in winter.

[0076] See Figure 1 and Figure 2 In this embodiment, the centralized air conditioning system with independently set supply and exhaust fans and variable fresh air function proposed in this technical solution can detect changes in outdoor fresh air temperature and humidity, and automatically adjust the fresh, return and exhaust air ratio according to the enthalpy value of outdoor fresh air, so that the fresh air volume of the centralized air conditioning system can be automatically adjusted within the range of 10% to 100%, or switch between 10% and 100%. In the spring and autumn transition seasons, the system can make extensive use of outdoor fresh air, reduce the output of the chiller unit, thereby saving energy and reducing operating costs.

[0077] See Figure 1 and Figure 2 In this embodiment, the centralized air conditioning system can adapt to fluctuations in outdoor temperature and humidity, maximize the use of outdoor fresh air, and enable the centralized air conditioning system to operate in an energy-efficient and high-performance state throughout the year, thereby saving energy and reducing operating costs to the greatest extent. This overcomes the shortcomings of existing centralized air conditioning systems that use a single fan system, operate with a fixed fresh air ratio throughout the year, or have independent supply and exhaust fans but do not have variable fresh air operation adjustment.

[0078] See Figure 1 and Figure 2In this embodiment, the centralized air conditioning system has the function of automatically adjusting the ratio of fresh air, return air and exhaust air, which can meet the year-round energy-efficient operation under various working conditions such as summer cooling, winter heating, fresh air in the transition season, and fresh air changing from summer to transition season to winter. It can achieve the purpose of energy saving and consumption reduction, which is practical and effective.

[0079] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A centralized air conditioning system with independently installed supply and exhaust fans and a variable fresh air function, characterized in that: It includes an electrical control box (1), a fresh air duct (2), a supply air duct (3), a return air duct (4), and an exhaust air duct (5); The fresh air duct (2) is connected to the return air duct (4), one end of the supply air duct (3) is connected to the connection between the fresh air duct (2) and the return air duct (4), the exhaust duct (5) is connected to the return air duct (4), and the exhaust port of the exhaust duct (5) is connected to an exhaust fan (6). The fresh air duct (2), the supply air duct (3), the return air duct (4) and the exhaust air duct (5) are respectively equipped with a fresh air valve (7), a combined air handling unit (8), a supply air valve (9), a return air valve (10) and an exhaust air valve (11), and the fresh air valve (7), the supply air valve (9), the return air valve (10) and the exhaust air valve (11) are all electrically connected to the electrical control box (1); There is a room (12) between the outlet of the air supply duct (3) and the inlet of the return air duct (4). The fresh air duct (2), the air supply duct (3), the room (12) and the return air duct (4) are all equipped with temperature and humidity sensors (13) that are electrically connected to the electrical control box (1). The combined air handling unit (8) has a differential pressure switch (14), an electric two-way regulating valve (15), a solenoid valve (16), a blower (17), and a pressure transmitter (18) that are electrically connected to the electrical control box (1).

2. A centralized air conditioning system with independently installed supply and exhaust fans and variable fresh air function as described in claim 1, characterized in that: The air inlet of the combined air handling unit (8) is provided with a primary and secondary filter (19), and the differential pressure switch (14) is electrically connected to both sides of the primary and secondary filter (19).

3. A centralized air conditioning system with independently installed supply and exhaust fans and variable fresh air function according to claim 2, characterized in that: The primary and secondary filters (19) are provided with a surface cooler heater (20) on the side near the air supply valve (9). The surface cooler heater (20) is fixed inside the combined air handling unit (8). The surface cooler heater (20) is connected to a hot and cold water pipe (21). The electric two-way regulating valve (15) is installed on the hot and cold water pipe (21).

4. A centralized air conditioning system with independently installed supply and exhaust fans and variable fresh air function as described in claim 3, characterized in that: The surface cooler heater (20) is provided with a humidifier (22) on the side near the air supply valve (9). The humidifier (22) is fixed inside the combined air handling unit (8). The humidifier (22) is connected to a humidifying water pipe (23). The solenoid valve (16) is installed on the humidifying water pipe (23).

5. A centralized air conditioning system with independently installed supply and exhaust fans and variable fresh air function according to claim 1, characterized in that: The blower (17) is located inside the combined air handling unit (8), and the pressure transmitter (18) is electrically connected to both ends of the blower (17).

6. A centralized air conditioning system with independently installed supply and exhaust fans and variable fresh air function according to claim 4, characterized in that: The hot and cold water pipes (21) and the humidifying water pipes (23) are connected to the surface cooling heater (20) and the humidifier (22) respectively through the first flexible connector (24) and the second flexible connector (25).

7. A centralized air conditioning system with independently installed supply and exhaust fans and variable fresh air function according to claim 4, characterized in that: Both the hot and cold water pipes (21) and the humidifying water pipe (23) are equipped with butterfly valves (26).

8. A centralized air conditioning system with independently installed supply and exhaust fans and variable fresh air function according to claim 1, characterized in that: A first temperature and humidity sensor (27) is installed on the fresh air duct (2). The first temperature and humidity sensor (27) is located on the side of the fresh air valve (7) near the air inlet of the fresh air duct (2). The first temperature and humidity sensor (27) is electrically connected to the electrical control box (1) through a first signal line (28). A second temperature and humidity sensor (29) is installed on the air supply duct (3). The second temperature and humidity sensor (29) is located on the air supply duct (3) between the combined air handling unit (8) and the air supply valve (9). The second temperature and humidity sensor (29) is electrically connected to the electrical control box (1) through a second signal line (30). The room (12) is equipped with a third temperature and humidity sensor (31), which is electrically connected to the electrical control box (1) via a third signal line (32). A fourth temperature and humidity sensor (33) is installed on the return air duct (4). The fourth temperature and humidity sensor (33) is located on the return air duct (4) between the return air valve (10) and the exhaust duct (5). The fourth temperature and humidity sensor (33) is electrically connected to the electrical control box (1) through a fourth signal line (34).

9. A centralized air conditioning system with independently installed supply and exhaust fans and variable fresh air function according to claim 1, characterized in that: The blower (17) is electrically connected to the electrical control box (1) via the fifth signal line (35), and the first distribution box (36) is electrically connected to the fifth signal line (35).

10. A centralized air conditioning system with independently installed supply and exhaust fans and variable fresh air function according to claim 1, characterized in that: The exhaust fan (6) is electrically connected to the electrical control box (1) via the sixth signal line (37), and the second distribution box (38) is electrically connected to the sixth signal line (37).

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