A heat recovery system for an air conditioning unit and an air conditioning fresh air unit

Abstract

This utility model relates to the field of air conditioning unit technology, and in particular to a heat recovery system for air conditioning units and an air conditioning fresh air handling unit. The heat recovery system consists of a first heat recovery coil and a second heat recovery coil installed on both sides of the original air conditioning unit's surface cooler, forming a closed-loop system via circulation pipes and a power pump station. The first heat recovery coil efficiently recovers heat from the fresh air and reduces the load on the surface cooler, transferring the heat to the second heat recovery coil via the circulation pipes. The second heat recovery coil then uses the recovered heat from the fresh air to reheat the low-temperature air after dehumidification by the surface cooler, reducing the consumption of reheat steam and dehumidification chilled water. This structure fundamentally solves the energy offsetting problem caused by the "cooling and dehumidifying before heating" process in traditional air conditioning units, significantly reducing the unit's reheat energy consumption and the surface cooler's cooling load, achieving energy saving and emission reduction. Furthermore, an air conditioning fresh air handling unit with the aforementioned heat recovery system is also provided.

Description

Technical Field

[0001] This utility model relates to the field of air conditioning unit technology, and in particular to a heat recovery system for air conditioning units and an air conditioning fresh air unit. Background Technology

[0002] Driven by the "dual carbon" goals and national green development policies, reducing the energy consumption of large public buildings and industrial plants, especially the energy consumption of air conditioning systems, has become a key focus of current energy conservation and emission reduction efforts. In air conditioning systems, the main air handling unit (MAU) is a crucial piece of equipment for ensuring indoor air quality and handling the fresh air load, and its energy consumption cannot be ignored. Especially in summer, fresh air is typically characterized by high temperature and high humidity. The unit needs to first deeply dehumidify the air, and then heat the excessively low-temperature air to a suitable supply air temperature through a reheating process. The "cold-heat cancellation" phenomenon in this process leads to significant energy waste. Currently, common technical means to reduce the reheat energy consumption of MAUs include using traditional methods such as electric heating or steam heating for direct reheating, which consumes a huge amount of energy; or using devices such as heat pipe heat recovery units for energy recovery. While heat pipe technology has some energy-saving effects, the traditional, simple duct design at the fresh air inlet results in low overall system heat transfer efficiency and temperature difference adaptability. Utility Model Content

[0003] This application discloses a heat recovery system for air conditioning units and an air conditioning fresh air handling unit, in order to solve the technical problems of low heat transfer efficiency and low temperature difference adaptability of existing air conditioning heat recovery systems in related technologies.

[0004] To solve the above problems, the present invention adopts the following technical solution: This utility model provides a heat recovery system for an air conditioning unit, comprising: a first heat recovery coil disposed on the fresh air inlet side of the surface cooler in the air conditioning unit; a second heat recovery coil disposed on the air outlet side of the surface cooler; a circulation pipeline fluidly connecting the outlet of the first heat recovery coil to the inlet of the second heat recovery coil, and the outlet of the second heat recovery coil to the inlet of the first heat recovery coil; and a power pump station disposed on the circulation pipeline for driving the heat exchange medium to circulate between the first heat recovery coil and the second heat recovery coil.

[0005] Preferably, the power pump station includes a water pump, an expansion tank, a safety valve, and a filter, which are integrated on a common base via pipes and threaded connections.

[0006] Preferably, a control loop is also provided on the circulation pipeline. The control loop includes an electric three-way valve and a bypass pipeline. The inlet of the electric three-way valve is connected to the outlet pipeline of the first heat recovery coil, and the other two outlets are respectively connected to the inlet of the second heat recovery coil and the inlet of the bypass pipeline. The outlet of the bypass pipeline is connected to the outlet pipeline of the second heat recovery coil.

[0007] Preferably, the control loop further includes a control unit, which is electrically connected to the electric three-way valve; a temperature sensor is connected to the signal input terminal of the control unit.

[0008] To solve the above-mentioned technical problems, this utility model also provides an air conditioning fresh air handling unit, including an air inlet box, a blower, a pre-filter, a medium-efficiency filter, a surface cooler, and an air outlet box. The unit is characterized by further including a heat recovery system for an air conditioning unit as described in any one of claims 1-5; the air inlet box is connected to the air outlet box, wherein the pre-filter, medium-efficiency filter, and surface cooler are sequentially arranged inside the air inlet box, and the blower is arranged inside the air outlet box; the first heat recovery coil is located between the medium-efficiency filter and the surface cooler; the second heat recovery coil is located between the surface cooler and the air outlet box; and the air inlet box has a pipe hole for connecting the circulation pipeline.

[0009] Preferably, the inlet water temperature of the cooling pipe of the surface cooler is 7℃-12℃.

[0010] Preferably, the pre-filter is a plate-type pre-filter.

[0011] Preferably, a rotary dehumidifier unit is provided between the air inlet box and the air outlet box.

[0012] The technical solution adopted in this utility model can achieve the following beneficial effects: 1. This utility model provides a heat recovery system for air conditioning units. A first heat recovery coil and a second heat recovery coil are respectively installed on the fresh air inlet side and the air outlet side of the existing air conditioning unit's surface cooler. These are connected to a closed-loop system via a circulation pipeline and a power pump station. The first heat recovery coil efficiently recovers heat from the fresh air and reduces the load on the air conditioning unit's surface cooler. The heat is then transferred to the second heat recovery coil via the circulation pipeline. The second heat recovery coil uses the recovered heat from the fresh air to reheat the dehumidified low-temperature air after dehumidification by the surface cooler, reducing the consumption of reheat steam and dehumidification chilled water. This structure fundamentally solves the energy offsetting problem caused by the "cooling and dehumidifying before heating" process in traditional air conditioning units, significantly reducing the unit's reheat energy consumption and the surface cooler's cooling load, thus achieving energy conservation and emission reduction.

[0013] 2. By setting up a control loop including an electric three-way valve and a bypass pipeline, precise and automatic adjustment of the flow rate of the medium passing through the second heat recovery coil is achieved. This structure allows the system to flexibly control the reheat capacity according to actual load changes, avoiding overheating or underheating, and further optimizing the system's energy-saving effect while ensuring stable supply air temperature.

[0014] 3. By setting a temperature sensor electrically connected to the control unit, a complete feedback control system is formed. This structure enables the system to monitor key temperature parameters (such as air supply temperature or medium temperature) in real time, and intelligently and accurately control the action of the electric three-way valve accordingly. This achieves fully automatic and efficient operation of the system, reduces manual intervention, and improves control accuracy and reliability.

[0015] 4. By highly integrating the water pump, expansion tank, safety valve, and filter onto a common base via threaded connections, a modular power pump station is formed. This structure makes the pump station compact, easy to transport and install on-site, reduces the complexity of pipeline connections and the risk of leakage, while the integration of safety valves and filters ensures the safety of system operation and the cleanliness of the media, reducing the complexity of later maintenance.

[0016] 5. This utility model also provides an air conditioning fresh air handling unit, including an air inlet box, a blower, a pre-filter, a medium-efficiency filter, a surface cooler, and an air outlet box, and also includes a heat recovery system for the air conditioning unit as described above; the air inlet box and the air outlet box are connected, wherein the pre-filter, the medium-efficiency filter, the surface cooler, and the blower are sequentially arranged inside the air inlet box, the first heat recovery coil is located between the medium-efficiency filter and the surface cooler; the second heat recovery coil is located between the surface cooler and the blower; the air inlet box has a pipe hole for connecting the circulation pipeline; it has the same beneficial effects as the heat recovery system described above, and at the same time clarifies the optimal arrangement position of the first and second heat recovery coils between the filter section and the surface cooler section, so that the unit adds a high-efficiency heat recovery function while retaining the original function.

[0017] 6. By limiting the pre-filter to a plate-type pre-filter, its structure is more compact compared to the traditional bag filter. This allows for more space inside the housing to install components such as heat recovery coils while ensuring filtration efficiency, providing a key structural foundation for the integrated transformation of the entire heat recovery system. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a circuit diagram of a heat recovery system for an air conditioning unit disclosed in some embodiments of this application; Figure 2 This is a circuit diagram of an air conditioning fresh air handling unit disclosed in some embodiments of this application.

[0020] In the picture: 1. A heat recovery system for an air conditioning unit; 2. An air conditioning fresh air handling unit; 10. First heat recovery coil; 11. Second heat recovery coil; 12. Circulation pipeline; 13. Power pump station; 20. Inlet air box; 21. Blower; 22. Pre-filter; 23. Medium-efficiency filter; 24. Surface cooler; 25. Outlet air box; 26. Rotary dehumidifier unit; 120. Control circuit; 130. Water pump; 131. Expansion tank; 132. Filter; 133. Safety valve; 1200, Electric three-way valve; 1201, Bypass pipeline; 1202, Control unit. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0022] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0023] Currently, common technical means to reduce the reheat energy consumption of fresh air handling units mainly include two types: one is to use traditional methods such as electric heating or steam heating for direct reheating. This method uses high-grade energy sources and consumes a lot of energy, which runs counter to the goal of economic energy conservation; the other is to use devices such as heat pipe heat recovery units for energy recovery. Although heat pipe technology has a certain energy-saving effect, its heat transfer efficiency and temperature difference adaptability are limited. It is usually less efficient and can only achieve a small temperature difference range, so its energy-saving potential has not been fully explored.

[0024] For example, in combined air conditioning units commonly used in industries such as pharmaceuticals and electronics, the air handling process typically employs a "deep dehumidification by surface cooler, secondary dehumidification by rotary dehumidifier, and reheating" method. This process has significant drawbacks: First, the regeneration process of the rotary dehumidifier itself consumes a large amount of steam heat energy, and its operation also consumes electricity; second, the air temperature after being processed by the rotary dehumidifier is too high, and after being sent to the downstream air handling unit (AHU), the AHU still needs to consume cooling capacity to lower its temperature, resulting in secondary energy waste. This leads to persistently high energy consumption for the entire air conditioning system.

[0025] The following is in conjunction with the appendix Figures 1 to 2 The present application provides a detailed description of a heat recovery system 1 for an air conditioning unit and an air conditioning fresh air unit 2 through specific embodiments and application scenarios.

[0026] Please refer to Figure 1 In the diagram, the large arrow indicates the direction of fresh air flow, and the small arrow indicates the flow direction of the heat exchange medium in the pipeline. This utility model embodiment provides a heat recovery system 1 for an air conditioning unit, including a first heat recovery coil 10, which is disposed on the fresh air inlet side of the surface cooler 24 in the air conditioning unit, and a second heat recovery coil 11, which is disposed on the air outlet side of the surface cooler 24. It also includes a circulation pipeline 12, which fluidly connects the outlet of the first heat recovery coil 10 and the inlet of the second heat recovery coil 11, and connects the outlet of the second heat recovery coil 11 and the inlet of the first heat recovery coil 10. It also includes a power pump station 13, which is disposed on the circulation pipeline 12 and is used to drive the heat exchange medium to circulate between the first heat recovery coil 10 and the second heat recovery coil 11.

[0027] Understandably, by installing a first heat recovery coil 10 and a second heat recovery coil 11 on the fresh air inlet side and the air outlet side of the existing air conditioning unit's surface cooler 24, respectively, and forming a closed-loop circulation system via circulation pipe 12 and power pump station 13, the first heat recovery coil 10 can efficiently recover the heat from the fresh air and reduce the load on the air conditioning unit's surface cooler 24. The heat is then transferred to the second heat recovery coil 11 via circulation pipe 12. The second heat recovery coil 11 then uses the recovered heat from the fresh air to reheat the low-temperature air after dehumidification by the surface cooler 24, reducing the consumption of reheat steam and dehumidification chilled water. This structure fundamentally solves the energy offsetting problem caused by "cooling and dehumidifying before heating" in traditional air conditioning units, significantly reducing the unit's reheat energy consumption and the cooling load of the surface cooler, thus achieving the goal of energy saving and emission reduction.

[0028] Specifically, in order to improve operating efficiency, the coil surface area of ​​the first heat recovery coil 10 and the second heat recovery coil 11 is the same as the cooling surface area of ​​the surface cooler.

[0029] Furthermore, a control loop 120 is also provided on the circulation pipeline 12. The control loop 120 includes an electric three-way valve 1200 and a bypass pipeline 1201. The inlet of the electric three-way valve 1200 is connected to the outlet pipeline of the first heat recovery coil 10, and the other two outlets are connected to the inlet of the second heat recovery coil 11 and the inlet of the bypass pipeline 1201, respectively. The outlet of the bypass pipeline 1201 is connected to the outlet pipeline of the second heat recovery coil 11.

[0030] Understandably, by setting up a control loop including an electric three-way valve 1200 and a bypass pipe 1201, the flow rate of the medium flowing through the second heat recovery coil 11 is accurately and automatically adjusted. This structure enables the system to flexibly control the reheat capacity according to actual load changes, avoiding overheating or underheating, and further optimizing the energy-saving effect of the system while ensuring stable supply air temperature.

[0031] Furthermore, the control loop 120 also includes a control unit 1202, which is electrically connected to the electric three-way valve 1200; a temperature sensor is connected to the signal input terminal of the control unit 1202.

[0032] Specifically, the electric three-way valve 1200 is an electric proportional regulating three-way valve. It adjusts the flow ratio of the heat exchange medium between the bypass pipe 1201 and the circulation pipe 12 in real time by sensing the supply air temperature or medium temperature through a temperature sensor, thereby achieving precise temperature control.

[0033] Understandably, by setting a temperature sensor electrically connected to the control unit 1202, a complete feedback control system is formed. This structure enables the system to monitor key temperature parameters (such as air supply temperature or medium temperature) in real time, and intelligently and accurately control the action of the electric three-way valve accordingly, realizing the fully automatic and efficient operation of the system, reducing manual intervention, and improving control accuracy and reliability.

[0034] Furthermore, the power pump station 13 includes a water pump 130, an expansion tank 131, a safety valve 133, and a filter 132. The water pump 130, expansion tank 131, safety valve 133, and filter 132 are integrated on a common base through pipe and threaded connection.

[0035] Understandably, by highly integrating the water pump 130, expansion tank 131, safety valve 133, and filter 132 onto a common base via threaded connections, a modular power pump station is formed. This structure makes the overall structure of the pump station compact, easy to transport and install on site, reduces the complexity of pipeline connections and the risk of leakage, and at the same time, the integration of safety valve 133 and filter 132 also ensures the safety of system operation and the cleanliness of the medium, reducing the complexity of later maintenance.

[0036] Specifically, the expansion tank 131 is a water pressure replenishment device. When the system loses water and the pressure drops, the compressed gas in the air bladder expands and squeezes out the stored water to replenish the system. When pressurized water enters, the gas is compressed and stored until the gas-liquid pressure is balanced, thus maintaining the stable liquid flow in the circulation pipeline.

[0037] Please combine Figure 1 and Figure 2 Another embodiment of this utility model also provides an air conditioning fresh air unit 2, including a heat recovery system 1 for an air conditioning unit as provided in the above embodiment, as well as an air inlet box 20, a blower 21, a primary filter 22, a secondary filter 23, a surface cooler 24, and an air outlet box 25; the air inlet box 20 and the air outlet box 25 are connected, wherein the primary filter 22, the secondary filter 23, and the surface cooler 24 are sequentially arranged in the air inlet box 20, and the blower 21 is arranged in the air outlet box 25; the first heat recovery coil 10 is located between the secondary filter 23 and the surface cooler 24; the second heat recovery coil 11 is located between the surface cooler 24 and the blower 21; the air inlet box 20 has a pipe hole for connecting the circulation pipe 12.

[0038] Understandably, in addition to having the same technical effect as the heat recovery system 1 for air conditioning units in the aforementioned embodiments, the air conditioning fresh air unit 2 also adds a high-efficiency heat recovery function by clarifying the optimal arrangement position of the first and second heat recovery coils between the filter section and the surface cooling section, so that the unit retains its original functions.

[0039] Furthermore, the inlet water temperature of the cooling pipe of the surface cooler 24 is 7℃-12℃, preferably 10℃.

[0040] Specifically, by limiting the inlet water temperature of the cooling pipe of the surface cooler 24 to a specific range of 7℃-12℃, it is ensured that the surface of the cooling pipe of the surface cooler 24 can reach a sufficiently low temperature, so that when the fresh air flows through the surface cooler 24, its temperature can drop below the dew point, achieving effective dehumidification; at the same time, 7℃-12℃ is a safe and efficient operating range, avoiding the risk of the cooling pipe freezing and increasing the service life of the device.

[0041] Furthermore, the pre-filter 22 is a plate-type pre-filter.

[0042] Understandably, compared to traditional bag-type pre-filters, plate-type pre-filters have a more compact structure, which can ensure filtration efficiency while freeing up more space in the housing to install components such as heat recovery coils, providing a key structural foundation for the integrated transformation of the entire heat recovery system.

[0043] Furthermore, a rotary dehumidifier unit 26 is installed between the air inlet box 20 and the air outlet box 25.

[0044] Specifically, by setting up a rotary dehumidifier unit 26 and having this heat recovery system coexist with it, a multi-stage dehumidification composite system is formed. This structure allows the unit to complete the main dehumidification and temperature control tasks under most operating conditions by relying on the efficient heat recovery system, significantly reducing the start-up time and energy consumption of the rotary dehumidifier. The rotary dehumidifier unit 26 is only activated for deep dehumidification under extremely high humidity conditions, thereby minimizing overall energy consumption while ensuring dehumidification effect, and also ensuring that the overall equipment can adapt to extreme operating conditions.

[0045] The present invention provides a heat recovery system for air conditioning units and an air conditioning fresh air handling unit, which, compared with the prior art, has the following advantages: This utility model provides a heat recovery system for air conditioning units. The system involves installing a first heat recovery coil and a second heat recovery coil on the fresh air inlet and outlet sides of the existing air conditioning unit's cooling coil, respectively. These coils are connected to a circulation pipeline and a power pump station to form a closed-loop system. The first heat recovery coil efficiently recovers heat from the fresh air and reduces the load on the air conditioning unit's cooling coil. The heat is then transferred to the second heat recovery coil via the circulation pipeline. The second heat recovery coil uses the recovered heat from the fresh air to reheat the dehumidified, low-temperature air, reducing the consumption of reheat steam and dehumidifying chilled water. This structure fundamentally solves the energy offsetting problem caused by the traditional "cooling, dehumidifying, and then heating" process in air conditioning units, significantly reducing the unit's reheat energy consumption and the cooling load on the cooling coil, thus achieving energy conservation and emission reduction.

[0046] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0047] Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

[0048] The above description is only a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model.

Claims

1. A heat recovery system for an air conditioning unit, characterized in that, include: The first heat recovery coil is installed on the fresh air inlet side of the surface cooler in the air conditioning unit. The second heat recovery coil is located on the air outlet side of the surface cooler; The circulation pipeline is fluidly connected to the outlet of the first heat recovery coil and the inlet of the second heat recovery coil, and the outlet of the second heat recovery coil and the inlet of the first heat recovery coil. A power pump station is installed on the circulation pipeline to drive the heat exchange medium to circulate between the first heat recovery coil and the second heat recovery coil.

2. The heat recovery system for an air conditioning unit according to claim 1, characterized in that, The circulation pipeline is also equipped with a control loop, which includes an electric three-way valve and a bypass pipeline. The inlet of the electric three-way valve is connected to the outlet pipeline of the first heat recovery coil, and the other two outlets are respectively connected to the inlet of the second heat recovery coil and the inlet of the bypass pipeline. The outlet of the bypass pipeline is connected to the outlet pipeline of the second heat recovery coil.

3. A heat recovery system for an air conditioning unit according to claim 2, characterized in that, The control loop also includes a control unit, which is electrically connected to the electric three-way valve; a temperature sensor is connected to the signal input terminal of the control unit.

4. A heat recovery system for an air conditioning unit according to claim 1, characterized in that, The power pump station includes a water pump, an expansion tank, a safety valve, and a filter. The water pump, expansion tank, safety valve, and filter are integrated on a common base through pipe and threaded connection.

5. An air conditioning fresh air handling unit, comprising an air inlet housing, a blower, a pre-filter, a medium-efficiency filter, a surface cooler, and an air outlet housing, characterized in that, It also includes a heat recovery system for an air conditioning unit as described in any one of claims 1-4; the air inlet box is connected to the air outlet box, wherein a primary filter, a medium-efficiency filter and a surface cooler are sequentially arranged in the air inlet box, the blower is arranged in the air outlet box, the first heat recovery coil is located between the medium-efficiency filter and the surface cooler; the second heat recovery coil is located between the surface cooler and the air outlet box; and the air inlet box has a pipe hole for connecting the circulation pipeline.

6. An air conditioning fresh air handling unit according to claim 5, characterized in that, The inlet water temperature of the cooling pipe of the surface cooler is 7℃-12℃.

7. An air conditioning fresh air handling unit according to claim 5, characterized in that, The primary filter is a plate-type primary filter.

8. An air conditioning fresh air handling unit according to claim 5, characterized in that, A rotary dehumidifier unit is installed between the air inlet box and the air outlet box.

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