Air volume adjusting device

Abstract

The utility model relates to the technical field of drying equipment, and discloses an air volume adjusting device which is characterized in that circulating air absorbing sludge moisture in a sludge drying chamber is divided into two paths of airflow by an air volume adjusting valve, one path of airflow flows through a first heat exchange pipeline of a heat regenerator from a first airflow channel and then enters an evaporator to realize heat exchange and dehumidification, and the other path of airflow flows through a second heat exchange pipeline of a heat regenerator; the cooled and dehumidified return air flow enters the heat regenerator again from a second heat exchange pipeline of the heat regenerator to be preheated, and then is mixed with the other path of return air which is shunted by the air volume adjusting valve and enters the second air flow channel to enter the condenser to be heated; the mixed circulating return air is heated into high-temperature low-humidity air, and the high-temperature low-humidity air is powered by the fan and enters the sludge drying chamber through the air inlet channel, so that not only can circulating drying be realized, but also the resistance of circulating return air flow can be reduced, and the energy consumption of the fan at the moment can be reduced; and the compressor is ensured to operate in an efficient and reasonable range by adjusting the air quantity passing through the condenser, so that the cold and heat balance of the sludge drying system is ensured.

Description

Technical Field

[0001] This utility model relates to the field of drying equipment technology, specifically to an air volume regulating device. Background Technology

[0002] Sludge drying is one of the effective methods to drastically reduce the volume of sludge, and it is a key to sludge reduction, harmless treatment, and a prerequisite for resource utilization. Low-temperature sludge drying is driven by heat and water vapor partial pressure, causing a phase change in the water in the sludge, which then separates from the solid particles, thus achieving dehydration. It mainly includes two processes: evaporation and diffusion, and condensation and dehumidification.

[0003] Evaporation and diffusion process: The moisture on the surface of the sludge particles absorbs heat and vaporizes, entering the air medium on the surface under the action of the water vapor partial pressure difference; after the moisture on the surface of the material is evaporated, the humidity on the surface of the material will be lower than the humidity inside the material, and heat is required to drive the moisture to transfer from the inside to the surface.

[0004] Condensation dehumidification process: Water vapor evaporated from the sludge enters the circulating air, and the circulating air comes into contact with surfaces with a temperature lower than its dew point, causing the water vapor to condense into water and be discharged.

[0005] By repeating the above two processes, the purpose of dehumidification is ultimately achieved.

[0006] To ensure the stable and reliable operation of both processes, the air volume of both processes needs to be adjusted to ensure sufficient heat during the evaporation and diffusion process and appropriate cooling during the condensation and dehumidification process. Utility Model Content

[0007] In view of this, the present invention provides an air volume regulating device that can control the return air volume of two airflow channels by adjusting the air volume regulating valve, thereby reducing the resistance of the circulating return airflow, reducing the fan energy consumption at this time, ensuring the latent heat ratio in the evaporator heat exchange process, and ensuring the heat and cold balance of the sludge drying system.

[0008] To achieve the above technical effects, this utility model provides an airflow regulating device, comprising:

[0009] A return air duct is connected to the interior of the drying chamber, and a first airflow duct and a second airflow duct are provided at the outlet end of the return air duct;

[0010] An air volume regulating valve is installed at the outlet of the return air duct to regulate the return air volume entering the first airflow duct and the second airflow duct.

[0011] An air inlet channel, one end of which is connected to the inner cavity of the drying chamber, and the other end of which is connected to the second airflow channel;

[0012] A heat pump, comprising a compressor, a condenser, an expansion valve, and an evaporator connected by a circulation pipe; the condenser is disposed between an air inlet channel and a second airflow channel, and is used to provide heat to the airflow entering the air inlet channel; the evaporator is connected to a first airflow channel, and is used to condense and dehumidify the return air in the first airflow channel;

[0013] The regenerator includes a first heat exchange pipeline and a second heat exchange pipeline arranged in a cross manner. The first heat exchange pipeline is used to connect a first airflow channel and the air inlet of the evaporator. One end of the second heat exchange pipeline is connected to the air outlet of the evaporator, and the other end of the second heat exchange pipeline is connected to the air inlet of the condenser.

[0014] Furthermore, a return air valve for adjusting the return air volume is provided in the return air duct.

[0015] Furthermore, a surface cooler is provided between the return air duct and the first airflow duct to pre-cool the return air entering the first airflow duct.

[0016] Furthermore, the surface cooler includes a heat exchange plate, and a heat exchange coil is disposed inside the heat exchange plate.

[0017] Furthermore, a flow regulating valve is provided on the heat exchange coil.

[0018] Furthermore, it also includes an electric heater, which is disposed in the air inlet channel between the condenser and the drying chamber.

[0019] Furthermore, a gas-liquid separator is provided on the circulation pipeline between the evaporator and the compressor.

[0020] Furthermore, a filter is installed on the circulation pipe between the condenser and the expansion valve.

[0021] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model uses an air volume regulating valve to divide the circulating air that absorbs moisture from the sludge in the sludge drying chamber into two airflows. One airflow flows from the first airflow channel through the first heat exchange pipe of the regenerator and then enters the evaporator to achieve heat exchange and dehumidification. The cooled and dehumidified return airflow enters the regenerator again through the second heat exchange pipe of the regenerator for preheating. Then, it mixes with the other return air that has been diverted by the air volume regulating valve into the second airflow channel and enters the condenser for heating. The mixed circulating return air is heated to a high temperature and low humidity air, which is powered by the fan and enters the sludge drying chamber through the air inlet channel. This not only achieves circulating drying but also reduces the resistance of the circulating return airflow and reduces the fan energy consumption. Moreover, by adjusting the airflow through the condenser, the compressor is ensured to operate within a high-efficiency and reasonable range, thereby ensuring the heat balance of the sludge drying system. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the air volume regulating device in the embodiment;

[0024] The components are as follows: 1. Return air duct; 2. First airflow duct; 3. Second airflow duct; 4. Air volume regulating valve; 5. Air inlet duct; 6. Compressor; 7. Condenser; 8. Expansion throttle valve; 9. Evaporator; 10. Regenerator; 11. Return air valve; 12. Heat exchange plate; 13. Heat exchange coil; 14. Flow regulating valve; 15. Electric heater; 16. Gas-liquid separator; 17. Filter. Detailed Implementation

[0025] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0026] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] Example

[0028] See Figure 1 An airflow regulating device, comprising:

[0029] Return air duct 1, which is connected to the interior cavity of the drying chamber, and the outlet end of return air duct 1 is provided with a first airflow duct 2 and a second airflow duct 3;

[0030] Air volume regulating valve 4 is located at the outlet of the return air channel 1 and is used to regulate the return air volume entering the first airflow channel 2 and the second airflow channel 3;

[0031] Air inlet channel 5, one end of which is connected to the inner cavity of the drying chamber, and the other end of which is connected to the second airflow channel 3;

[0032] A heat pump, comprising a compressor 6, a condenser 7, an expansion valve 8, and an evaporator 9 connected by a circulation pipe; the condenser 7 is disposed between an air inlet channel 5 and a second airflow channel 3, and is used to provide heat to the airflow entering the air inlet channel 5; the evaporator 9 is connected to a first airflow channel 2, and is used to condense and dehumidify the return air in the first airflow channel 2.

[0033] The regenerator 10 includes a first heat exchange pipe and a second heat exchange pipe arranged in a cross manner. The first heat exchange pipe is used to connect the first airflow channel 2 and the air inlet of the evaporator 9. One end of the second heat exchange pipe is connected to the air outlet of the evaporator 9, and the other end of the second heat exchange pipe is connected to the air inlet of the condenser 7.

[0034] In this embodiment, the circulating air that absorbs moisture from the sludge in the sludge drying chamber is divided into two airflows by the airflow regulating valve 4 through the return air channel 1. One airflow flows from the first airflow channel 2 through the first heat exchange pipe of the regenerator 10 and then enters the evaporator 9 to achieve heat exchange and dehumidification. The cooled and dehumidified return airflow enters the regenerator 10 again through the second heat exchange pipe of the regenerator 10 for preheating. Then, it mixes with the other return air that has been divided by the airflow regulating valve 4 and enters the second airflow channel 3 and enters the condenser 7 for heating. The mixed circulating return air is heated to high temperature and low humidity air and is powered by the fan to enter the sludge drying chamber through the air inlet channel 5 to achieve circulating drying.

[0035] Furthermore, the airflow regulating valve 4 in this embodiment serves two purposes. First, when the heat pump unit starts at low temperatures and the temperature of the circulating return air is lower than a set value (which can be set, such as 35°C in this embodiment), adjusting the airflow regulating valve 4 allows the circulating return air to enter the regenerator 10 and evaporator 9 through the first airflow channel 2 as much as possible, reducing the resistance of the circulating return airflow and lowering the fan energy consumption at this time. Second, during normal operation of the heat pump unit, adjusting the airflow regulating valve 4 regulates the return air volume passing through the condenser 7 and evaporator 9. This not only ensures the relative humidity of the circulating return air entering the evaporator 9, maintaining the latent heat ratio during the heat exchange process of the evaporator 9 and reducing the energy consumption of the entire system, but also stabilizes the high and low pressure of the refrigerant system by adjusting the airflow passing through the condenser 7, ensuring that the compressor 6 operates within a highly efficient and reasonable range, thereby ensuring the heat and cold balance of the sludge drying system.

[0036] In this embodiment, the heat pump operates as follows: Low-temperature, low-pressure refrigerant vapor is compressed in the compressor 6 and then into the condenser 7 to form high-temperature, high-pressure refrigerant vapor. The high-temperature, high-pressure refrigerant vapor releases heat in the condenser 7 and heats the airflow entering the air inlet channel 5. After heat exchange, the medium-temperature, low-pressure refrigerant liquid in the condenser 7 is throttled and depressurized through the expansion valve 8 and enters the evaporator 9 to form low-temperature, low-pressure refrigerant vapor, thereby condensing and dehumidifying the return airflow in the first airflow channel 2. Finally, the low-temperature, low-pressure refrigerant vapor enters the compressor 6 to complete the refrigerant cycle.

[0037] In this embodiment, a return air valve 11 for adjusting the return air volume is provided in the return air duct 1. By setting the return air valve 11, it can be opened before the heat pump is started and closed after it is shut down. Especially in combined heat pump applications, the return air valve 11 can effectively cut off the return airflow loop after the heat pump is unloaded and shut down, avoiding ineffective air circulation. Furthermore, the return air valve 11 also ensures that the normal operation of the system is not affected when the heat pump module is shut down for maintenance.

[0038] Furthermore, a surface cooler is provided between the return air channel 1 and the first airflow channel 2 to pre-cool the return air entering the first airflow channel 2. The return air after passing through the surface cooler exchanges heat with the low-temperature air after being cooled and dehumidified by the evaporator 9 in the regenerator 10. This process is an isohumidity cooling process, which can increase the relative humidity of the return air entering the evaporator 9, thereby increasing the latent heat ratio of the evaporator 9, reducing the required cooling capacity for removing moisture from the return air, and thus improving dehumidification efficiency. In this embodiment, the surface cooler includes a heat exchange plate 12, within which a heat exchange coil 13 is installed. Cooling water cooled by the cooling tower can enter the heat exchange coil 13 to exchange heat with the circulating return air in the first airflow channel 2. In this embodiment, a flow regulating valve 14 is provided on the heat exchange coil 13 to accurately control the temperature of the circulating return air by controlling the flow rate of the cooling water, ensuring that the heat pump system can operate stably and reliably within a wider range of operating conditions.

[0039] It also includes an electric heater 15, which is disposed in the air inlet channel 5 between the condenser 7 and the drying chamber. The electric heater 15 can provide electric auxiliary heating to the airflow in the air inlet channel 5 when the heating temperature of the condenser 7 does not meet the requirements, so as to ensure that the drying temperature in the sludge drying chamber meets the requirements.

[0040] In this embodiment, a gas-liquid separator 16 is installed on the circulation pipe between the evaporator 9 and the compressor 6 to prevent refrigerant droplets from entering the compressor 6 and causing unstable operation of the compressor 6. For similar reasons, a filter 17 can also be installed on the circulation pipe between the condenser 7 and the expansion valve 8 to filter out impurities in the refrigerant circulation system and ensure stable operation of the heat pump.

[0041] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An airflow regulating device, characterized in that, include: Return air duct (1), the return air duct (1) is connected to the drying chamber, and the outlet end of the return air duct (1) is provided with a first airflow duct (2) and a second airflow duct (3); An air volume regulating valve (4) is installed at the outlet of the return air channel (1) to regulate the return air volume entering the first airflow channel (2) and the second airflow channel (3); An air inlet channel (5) is provided, one end of which is connected to the inner cavity of the drying chamber, and the other end of which is connected to the second airflow channel (3). The heat pump includes a compressor (6), a condenser (7), an expansion valve (8), and an evaporator (9) connected by a circulation pipe; the condenser (7) is disposed between the air inlet channel (5) and the second airflow channel (3) to provide heat to the airflow entering the air inlet channel (5); the evaporator (9) is connected to the first airflow channel (2) to condense and dehumidify the return air in the first airflow channel (2); The regenerator (10) includes a first heat exchange pipeline and a second heat exchange pipeline arranged in a cross manner. The first heat exchange pipeline is used to connect the first airflow channel (2) and the air inlet of the evaporator (9). One end of the second heat exchange pipeline is connected to the air outlet of the evaporator (9), and the other end of the second heat exchange pipeline is connected to the air inlet of the condenser (7).

2. The air volume regulating device according to claim 1, characterized in that, The return air duct (1) is equipped with a return air valve (11) for adjusting the return air volume.

3. The air volume regulating device according to claim 1, characterized in that, A surface cooler is provided between the return air channel (1) and the first airflow channel (2) for pre-cooling the return air entering the first airflow channel (2).

4. The air volume regulating device according to claim 3, characterized in that, The surface cooler includes a heat exchange plate (12), and a heat exchange coil (13) is provided inside the heat exchange plate (12).

5. The air volume regulating device according to claim 4, characterized in that, A flow regulating valve (14) is provided on the heat exchange coil (13).

6. The air volume regulating device according to claim 1, characterized in that, It also includes an electric heater (15), which is disposed in the air inlet channel (5) between the condenser (7) and the drying chamber.

7. The air volume regulating device according to claim 1, characterized in that, A gas-liquid separator (16) is provided on the circulation pipe between the evaporator (9) and the compressor (6).

8. The air volume regulating device according to claim 1, characterized in that, A filter (17) is provided on the circulation pipe between the condenser (7) and the expansion throttle valve (8).

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