Heat pump type exhaust heat recovery unit

Abstract

The invention relates to the technical field of pollution gas heat recovery, and discloses a heat pump type exhaust heat recovery unit which comprises a heat recovery box and a heat pump circulation pipeline, and a hot air inlet of the recovery box is communicated with an exhaust port of a plant; the filter is used for filtering the polluted gas with heat and discharging the polluted gas after heat recovery through a cold air outlet; in the heat pump circulation pipeline, the refrigerant firstly absorbs heat in the heat recovery box, then is compressed, then releases the heat to the cold water, and finally returns to the heat recovery box. Polluted gas is collected and treated in a centralized mode and then discharged into the atmosphere, the external environment and the in-plant environment are prevented from being polluted, the interior of an existing plant does not need to be transformed, the space complexity of equipment arrangement is reduced, and flexible installation is facilitated; and the distance among the heat recovery box, the heat pump circulating pipeline and the plant is not strictly required, so that long-distance conveying of energy can be carried out.

Description

Technical Field

[0001] This invention relates to the field of heat recovery technology for polluted gases, specifically a heat pump type exhaust heat recovery unit. Background Technology

[0002] In some factories, large amounts of hot air are discharged, and heat recovery from the exhaust can improve energy efficiency. However, in specialized industrial fields such as radioactive facilities, the exhaust air often contains process pollutants due to the unique nature of their production processes. Directly releasing exhaust gases from radioactive facilities containing these pollutants into the environment will pollute the environment and result in heat loss. Furthermore, there is a potential risk of pollutants seeping into the fresh air supply, failing to meet the stringent cleanliness and safety requirements of this field.

[0003] Plate heat exchangers are used for heat recovery in order to isolate and collect polluted gases separately.

[0004] In existing technologies, the arrangement of plate heat exchangers requires that the fresh air ducts and exhaust ducts be arranged closely together, and there are strict requirements on the distance between the air supply and exhaust outlets. This greatly increases the difficulty of duct layout and engineering costs in existing factories with complex spaces or those that need to be renovated. Summary of the Invention

[0005] The purpose of this invention is to provide a heat pump type exhaust heat recovery unit to solve the problems mentioned in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a heat pump type exhaust heat recovery unit, comprising: A heat recovery box includes a hot air inlet and a cold air outlet, wherein the hot air inlet is connected to the factory exhaust outlet; it is used to filter pollutant gases with heat and discharge the pollutant gases after heat recovery through the cold air outlet. A heat pump circulation line, including the refrigerant flowing along it, in which the refrigerant first absorbs heat from the heat recovery tank, is then compressed, releases the heat to the cold water, and finally returns to the heat recovery tank.

[0007] Furthermore, the heat recovery box includes a box body, and also includes a filter, an evaporator and an exhaust fan arranged sequentially on the box body. The hot air inlet is located at one end of the heat recovery box near the filter, and the cold air outlet is located at the other end of the heat recovery box.

[0008] Furthermore, the evaporator is connected to the heat pump circulation pipeline via pipe one for discharging refrigerant; the evaporator is connected to the heat pump circulation pipeline via pipe two for returning refrigerant.

[0009] Furthermore, the heat pump circulation pipeline includes a compressor, a condenser, and an expansion valve arranged sequentially along the refrigerant flow direction. The compressor is used to pressurize the refrigerant; the condenser is used to release the heat of the refrigerant to cold water, which is then converted into hot water.

[0010] Furthermore, the heat pump circulation pipeline also includes a circulating water pump, which is connected to the condenser and is used to discharge hot water.

[0011] Furthermore, the filter is used to remove suspended particulate matter from polluted gases.

[0012] Furthermore, the hot air inlet is sealed to the existing main exhaust duct of the plant through corresponding pipes and airtight flanges.

[0013] Furthermore, the exhaust fan is used to drive the flow of polluted gas within the housing.

[0014] Furthermore, the evaporator employs a finned tube design.

[0015] Furthermore, the outlet pipe of the circulating water pump extends outside the contaminated area of ​​the plant.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention includes a heat recovery box and a heat pump circulation pipeline. The hot air inlet of the recovery box is connected to the factory exhaust outlet. It is used to filter pollutant gases carrying heat and discharge the pollutant gases after heat recovery through the cold air outlet. In the heat pump circulation pipeline, the refrigerant first absorbs heat from the heat recovery box, is then compressed, releases the heat to cold water, and finally returns to the heat recovery box. This invention centrally collects and treats pollutant gases before releasing them into the atmosphere, avoiding pollution of the external and internal environments. It eliminates the need for modifications to the existing factory interior, reduces the spatial complexity of equipment layout, and facilitates flexible installation. Furthermore, there are no strict requirements on the distance between the heat recovery box, the heat pump circulation pipeline, and the factory building, enabling long-distance energy transmission. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a structure according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure when it is connected to the factory exhaust port 5 in one embodiment of the present invention; In the diagram: 1. Heat recovery box; 2. Hot air inlet; 3. Cold air outlet; 4. Heat pump circulation pipeline; 5. Plant exhaust outlet; 6. Water outlet pipe; 11. Filter; 12. Evaporator; 13. Exhaust fan; 14. Pipe 1; 15. Pipe 2; 41. Compressor; 42. Condenser; 43. Expansion valve; 44. Circulating water pump. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] See Figures 1-2 This invention provides a technical solution: a heat pump type exhaust heat recovery unit, comprising: The heat recovery box 1 includes a hot air inlet 2, which is connected to the factory exhaust outlet 5; it is used to filter polluting gases with heat and discharge the polluting gases after heat recovery through the cold air outlet 3, collect and treat the polluting gases in a centralized manner, and then discharge them into the atmosphere to avoid polluting the external environment and the factory environment. The heat pump circulation line 4 includes a refrigerant flowing along it. In the heat pump circulation line 4, the refrigerant first absorbs heat from the heat recovery tank 1, then is compressed, then releases the heat to the cold water, and finally returns to the heat recovery tank 1.

[0020] Hot air inlet 2 is sealed to the existing main exhaust pipe of the plant through corresponding pipes and airtight flanges to ensure that there is no leakage during the exhaust air transportation process and to meet the special safety requirements of the radioactive plant. The heat recovery box 1 and the heat pump circulation pipeline 4 are both located outside the plant, without the need to modify the interior of the existing plant, reducing the spatial complexity of equipment layout and facilitating flexible installation. Moreover, there are no strict requirements on the distance between the heat recovery box 1, the heat pump circulation pipeline 4 and the plant, which allows for long-distance energy transportation.

[0021] In one embodiment, the heat recovery box 1 includes a box body, and further includes a filter 11, an evaporator 12, and an exhaust fan 13 arranged sequentially on the box body. The hot air inlet 2 is located at one end of the heat recovery box 1 near the filter 11, and the cold air outlet 3 is located at the other end of the heat recovery box 1. The evaporator 12 is connected to the heat pump circulation pipeline 4 through a first pipe 14 for discharging refrigerant. The evaporator 12 is also connected to the heat pump circulation pipeline 4 through a second pipe 15 for returning refrigerant.

[0022] This design, for reference Figure 1 Driven by the exhaust fan 13, the polluted gas carrying heat flows through the hot air inlet 2, filter 11, evaporator 12, exhaust fan 13 and cold air outlet 3; the exhaust air enters the evaporator 12, and the refrigerant inside the evaporator 12 evaporates at a lower pressure, absorbing the heat of the exhaust air flowing through the outer surface of the finned tube, thereby significantly reducing the exhaust air temperature; the refrigerant is transformed into low-temperature and low-pressure vapor due to heat absorption.

[0023] At the evaporator 12, the refrigerant absorbs heat from the polluting gas and is discharged through pipe 14 to the heat pump circulation line 4. After circulating once in the heat pump circulation line 4, the refrigerant is discharged to pipe 2 15 at the end of the heat pump circulation line 4 and finally flows back to the evaporator 12 for recycling. The filter 11 is used to remove suspended particulate matter in the exhaust air and protect the surface of the subsequent heat exchanger.

[0024] In one embodiment, the heat pump circulation pipeline 4 includes a compressor 41, a condenser 42, and an expansion valve 43 sequentially distributed along the refrigerant flow direction. The compressor 41 is used to pressurize the refrigerant; the condenser 42 is used to release the heat of the refrigerant to cold water, converting the cold water into hot water; the heat pump circulation pipeline 4 also includes a circulating water pump 44, which is connected to the condenser 42 and is used to discharge hot water.

[0025] This design, for reference Figure 1 Pipeline 14 is connected to compressor 41. Compressor 41 is connected to the heat medium inlet of condenser 42 through pipe 3. The heat medium outlet of condenser 42 is connected to expansion valve 43 through pipe 4. Expansion valve 43 is connected to pipe 2 15. During operation, the compression process is as follows: the low-temperature and low-pressure refrigerant gas flowing out of the evaporator 12 is in a vapor state, and the low-temperature and low-pressure refrigerant vapor is drawn into the compressor 41; the compressor 41 performs adiabatic compression on the refrigerant vapor, turning it into high-temperature and high-pressure superheated vapor. Condensation and heat release: The high-temperature, high-pressure refrigerant vapor then enters the condenser 42; in the condenser 42, the refrigerant exchanges heat counter-currently with the low-temperature circulating water from the refrigerant inlet. The refrigerant transfers heat to the cold water, is cooled, and condenses into a low-temperature, high-pressure liquid; Throttling process: The liquid refrigerant flowing out of the condenser 42 passes through the expansion valve 43; the expansion valve 43 precisely adjusts the opening according to the superheat of the evaporator 12 outlet to throttle and reduce the pressure of the refrigerant, so that it becomes a low-temperature and low-pressure vapor-liquid two-phase mixture again, and is sent back to the evaporator 12, thus completing a complete heat pump cycle.

[0026] The refrigerant is compressed into a high-temperature, high-pressure gas by compressor 41, and then enters condenser 42. In condenser 42, the refrigerant exchanges heat with the flowing cold water in a counter-current manner, releasing heat to the cold water and condensing itself into a liquid state. Finally, the liquid refrigerant is throttled and depressurized by expansion valve 43 and returns to evaporator 12 to begin continuous circulation.

[0027] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0028] It should be noted that if the embodiments of the invention involve directional indicators (such as up and down), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0029] Furthermore, the meaning of "and / or" throughout the text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Additionally, if the embodiments of the invention involve descriptions such as "first," "second," etc., these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, "multiple" refers to two or more.

[0030] Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the invention.

Claims

1. A heat pump type exhaust heat recovery unit, characterized in that, include: The heat recovery box (1) includes a hot air inlet (2) and a cold air outlet (3). The hot air inlet (2) is connected to the factory exhaust outlet (5). It is used to filter the polluting gas with heat and discharge the polluting gas that has completed heat recovery through the cold air outlet (3). The heat pump circulation line (4) includes the refrigerant flowing along it. In the heat pump circulation line (4), the refrigerant first absorbs heat in the heat recovery box (1), then is compressed, then releases the heat to the cold water, and finally returns to the heat recovery box (1).

2. The heat pump type exhaust heat recovery unit according to claim 1, characterized in that, The heat recovery box (1) includes a box body, and also includes a filter (11), an evaporator (12) and an exhaust fan (13) arranged sequentially on the box body. The hot air inlet (2) is located at one end of the heat recovery box (1) near the filter (11), and the cold air outlet (3) is located at the other end of the heat recovery box (1).

3. The heat pump type exhaust heat recovery unit according to claim 2, characterized in that, The evaporator (12) is connected to the heat pump circulation line (4) via pipe one (14) for discharging refrigerant; the evaporator (12) is connected to the heat pump circulation line (4) via pipe two (15) for returning refrigerant.

4. The heat pump type exhaust heat recovery unit according to claim 2, characterized in that, The heat pump circulation pipeline (4) includes a compressor (41), a condenser (42) and an expansion valve (43) arranged sequentially along the refrigerant flow direction. The compressor (41) is used to pressurize the refrigerant. The condenser (42) is used to release the heat of the refrigerant to the cold water, which is then converted into hot water.

5. The heat pump type exhaust heat recovery unit according to claim 4, characterized in that, The heat pump circulation line (4) also includes a circulating water pump (44), which is connected to the condenser (42) and is used to discharge hot water.

6. The heat pump type exhaust heat recovery unit according to claim 4, characterized in that, The filter (11) is used to remove suspended particulate matter from polluted gases.

7. The heat pump type exhaust heat recovery unit according to claim 4, characterized in that, The hot air inlet (2) is sealed to the original exhaust main pipe of the plant through corresponding pipes and airtight flanges.

8. The heat pump type exhaust heat recovery unit according to claim 7, characterized in that, The exhaust fan (13) is used to drive the polluted gas to flow inside the box.

9. The heat pump type exhaust heat recovery unit according to claim 3, characterized in that, The evaporator (12) is a finned tube type.

10. The heat pump type exhaust heat recovery unit according to claim 5, characterized in that, The outlet pipe (6) of the circulating water pump (44) extends outside the contaminated area of ​​the plant.

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