An air source heat pump system

Abstract

This application belongs to the field of drying technology, and specifically relates to an air source heat pump system. Current heat pump drying systems still have high energy consumption, indicating significant potential for energy conservation and emission reduction; the refrigerants used contribute to the greenhouse effect; and the operating temperature range of these drying systems is not highly adaptable. This application provides an air source heat pump system, comprising a centrifugal compressor, a drying chamber, a humid air expander, a gas-liquid separator, a drying filter, and a heat exchange assembly connected in sequence. The drying filter is connected to the centrifugal compressor, the heat exchange assembly is connected to the centrifugal compressor, and the drying chamber is connected to the drying filter. The centrifugal compressor is connected to the humid air expander via a main shaft. Indicator lights are installed on the drying chamber, displaying air status using different colors. This reduces heat loss during transfer, and the humid air expander can recover the internal energy and potential energy of the high-temperature, high-pressure, and high-humidity air in the system, improving the system's energy efficiency.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of drying, and particularly relates to an air source heat pump system. BACKGROUND

[0002] Drying is a mass and heat transfer process. Compared with mechanical and physical dehumidification methods, water removal in the drying dehumidification process is more thorough, can be removed from the inside to the surface of the material, and water changes, consumes more energy and costs more. In the 20th century, hot air drying technology is widely used in industrialized production. With the continuous enhancement of environmental protection consciousness in various countries, the traditional electric heating / combustion heating method for generating hot air cannot meet the requirements of energy saving and emission reduction. Therefore, the heat pump technology was proposed in the 1940s-1950s and was widely applied in the 1960s-1970s.

[0003] In the heat pump drying system, there are generally two loop circulations, a refrigerant loop circulation and a drying medium loop circulation. The refrigerant loop includes four main components: an evaporator, a compressor, a condenser and a throttling valve. The refrigerant circulates in the loop composed of the four components to realize heat transfer. The drying medium loop is composed of a drying chamber, an evaporator and a condenser.

[0004] In recent years, with the gradual improvement of people's requirements for high-quality living environment and the vigorous promotion of the state's energy saving and environmental protection, the traditional drying method has gradually failed to meet the needs of drying equipment and drying methods in modern industrialized mass production. The main problems existing in the current heat pump drying system are: 1. The system energy consumption is still high, and there is still great potential in energy saving and emission reduction; 2. The refrigerants used are generally R22, R134a, R410a, etc., which will aggravate the greenhouse effect; 3. When the refrigerant and the compressor are selected, the working temperature range of the system will be limited to a narrow range, resulting in poor adaptability of the working temperature range of the drying system. SUMMARY

[0005] 1. Technical problem to be solved

[0006] Based on the main problems existing in the current heat pump drying system: 1. The system energy consumption is still high, and there is still great potential in energy saving and emission reduction; 2. The refrigerants used are generally R22, R134a, R410a, etc., which will aggravate the greenhouse effect; 3. When the refrigerant and the compressor are selected, the working temperature range of the system will be limited to a narrow range, resulting in poor adaptability of the working temperature range of the drying system, the application provides an air source heat pump system.

[0007] 2. Technical scheme

[0008] In order to achieve the above-mentioned purpose, the application provides an air source heat pump system, which comprises a centrifugal compressor, a drying tank, a wet air expander, a gas-liquid separator, a drying filter and a heat exchange assembly connected in sequence, the drying filter is connected with the centrifugal compressor, the heat exchange assembly is connected with the centrifugal compressor, the drying tank is connected with the drying filter, the centrifugal compressor is connected with the wet air expander through a main shaft, the drying tank is provided with an indicator light, and the indicator light displays the air state through different colors.

[0009] Another embodiment provided by the application is that the drying tank is provided with a pressure sensor and a temperature and humidity sensor, the pressure sensor is connected with a frequency conversion controller, the temperature and humidity sensor is connected with the frequency conversion controller, the frequency conversion controller is connected with a frequency converter, the outer side of the main shaft is provided with an electric motor, the electric motor is connected with the centrifugal compressor, and the frequency converter is connected with the electric motor.

[0010] Another embodiment provided by the application is that a flow meter is arranged between the drying tank and the wet air expander, the inlet and outlet of the wet air expander are connected through a hand valve, and the flow meter, the hand valve and the gas-liquid separator are connected in sequence.

[0011] Another embodiment provided by the application is that the drying filter is connected with the heat exchange assembly and the centrifugal compressor through a three-way electromagnetic valve respectively.

[0012] Another embodiment provided by the application is that a first temperature sensor is arranged between the drying filter and the three-way electromagnetic valve, and a second temperature sensor is arranged between the heat exchange assembly and the centrifugal compressor.

[0013] Another embodiment provided by the application is that the heat exchange assembly comprises a heat exchanger and a fan.

[0014] Another embodiment provided by the application is that an electromagnetic valve is arranged between the drying filter and the drying tank, and a thermometer is arranged between the electromagnetic valve and the drying filter.

[0015] Another embodiment provided by the application is that the drying filter comprises a regeneration loop inlet and a regeneration loop outlet, and the regeneration loop inlet is connected with the electromagnetic valve.

[0016] Another embodiment provided by the application is that the gas-liquid separator comprises an air side outlet and a drainage port, and the air side outlet is connected with the drying filter.

[0017] Another embodiment provided in the application is that the drying filter is a renewable adsorption drying filter, and a drying agent is arranged in the drying filter, and the drying agent is potassium carbonate, silica gel, aluminum oxide or molecular sieve.

[0018] 3. Beneficial effects

[0019] Compared with the prior art, the air source heat pump system provided in the application has the beneficial effects that:

[0020] The air source heat pump system provided in the application is an air source heat pump system with a drying function.

[0021] The air source heat pump system provided in the application adopts a method of directly drying articles by using the exhaust gas of the compressor, so that the loss of heat in the transmission can be reduced, and the internal energy and potential energy in the high-temperature, high-pressure and high-humidity air in the system can be recovered by combining the wet air expander, so that the energy efficiency of the system is improved.

[0022] The air source heat pump system provided in the application can realize accurate control of the air temperature in the drying box and can realize a wide range of working temperature intervals of the drying box.

[0023] Compared with the prior art, the air source heat pump system provided in the application uses the high-temperature air directly discharged by the oil-free centrifugal compressor as a heat source to dry the articles to be dried. The traditional drying system needs to first heat the air by using the heat generated by the heat pump or the electric heater, and then uses the heated air to dry the articles. The air source heat pump system provided in the application adopts a method of directly drying articles by using the exhaust gas of the compressor, so that the loss of heat in the transmission can be reduced, and the system can be simplified.

[0024] The air source heat pump system provided in the application can realize a wide range of working intervals in the drying box. Specifically, the flow of the high-temperature air in the drying box is adjustable, the air temperature is adjustable, and the air pressure is adjustable. The flow is adjusted by adjusting the rotation speed of the compressor, the temperature is adjusted by adjusting the rotation speed of the compressor and the inlet temperature of the compressor (it should be noted that the air source heat pump system provided in the application can realize the adjustment of a wide range of air temperatures of 100-600℃), and the pressure is adjusted by adjusting the rotation speed of the compressor, so as to finally realize the wide range of working intervals of the drying box.

[0025] The air source heat pump system provided in the application can realize the monitoring of the temperature and humidity of the air in the drying box by arranging the pressure sensor and the temperature and humidity sensor in the drying box and matching the monitoring data with the frequency converter, and can realize the adjustment of the rotation speed of the compressor by controlling the frequency converter, so as to finally realize the control of the air temperature in the drying box.

[0026] The air source heat pump system provided by the application is provided with a regenerable adsorption drying filter and a compressed hot air flow path, and the drying filter can be regenerated by high-temperature exhaust gas of the compressor. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is an exploded schematic view of the structure of the air source heat pump system of the application. DETAILED DESCRIPTION

[0028] In the following, specific embodiments of the application will be described in detail with reference to the accompanying drawings, and based on these detailed descriptions, those skilled in the art can clearly understand the application and can implement the application. The features in each different embodiment can be combined to obtain new implementations, or some features in some embodiments can be replaced by other preferred implementations without departing from the principles of the application.

[0029] Referring to Figure 1 The application provides an air source heat pump system, which comprises a centrifugal compressor 1, a drying tank 5, a wet air expander 4, a gas-liquid separator 7, a drying filter 8 and a heat exchange assembly connected in sequence. The drying filter 8 is connected with the centrifugal compressor 1, the heat exchange assembly is connected with the centrifugal compressor 1, the drying tank 5 is connected with the drying filter 8, the centrifugal compressor 1 is connected with the wet air expander 4 through a main shaft 2, and the drying tank is provided with an indicator light. The indicator light displays the air state by different colors. The wet air expander 4 is connected with the centrifugal compressor 1 through the main shaft 2, and the outer side of the main shaft 2 is provided with an electric motor 3. The outlet of the wet air expander 4 is connected with the inlet of the gas-liquid separator 7. The wet air expander 4 can recover the internal energy and potential energy in the high-temperature, high-pressure and high-humidity air in the system and transmit them to the centrifugal compressor 1 through the main shaft 2, so as to greatly improve the energy efficiency of the system. A part of the power consumption of the centrifugal compressor 1 is provided by the wet air expander 4, and the other part is provided by the electric motor 3. When the air humidity is high, the indicator light is red, and after drying is completed, it is green. Of course, other states of air humidity can also be displayed by different colors, so that the operator can more easily observe.

[0030] The high-temperature air directly discharged by the oil-free centrifugal compressor 1 is used as a heat source to dry the drying object, and the wet air expander 4 coaxially connected with the centrifugal compressor 1 recovers the internal energy and potential energy in the high-temperature, high-pressure and high-humidity air in the system, so as to greatly improve the energy efficiency of the heat pump system.

[0031] Furthermore, a pressure sensor 51 and a temperature and humidity sensor 52 are installed inside the drying chamber 5. The pressure sensor 51 is connected to the frequency converter 14, the temperature and humidity sensor 52 is connected to the frequency converter 14, the frequency converter 14 is connected to the frequency converter 15, a motor 3 is installed on the outside of the main shaft 2, the motor 3 is connected to the centrifugal compressor 1, and the frequency converter 15 is connected to the motor 3.

[0032] The drying oven 5 is equipped with a pressure sensor 51 and a temperature and humidity sensor 52. The detection data of the pressure sensor 51 and the temperature and humidity sensor 52 can be fed back to the frequency converter 14. The frequency converter 14 can control the speed of the motor 3 through the frequency converter 15.

[0033] The drying oven 5 can achieve a wide operating range (adjustable air temperature and flow rate) by adjusting the speed of the centrifugal compressor 1, and the frequency converter can be controlled by the monitoring data feedback of the sensors installed in the drying oven 5, so as to achieve the purpose of automatically controlling the working state of the drying oven 5 by controlling the speed of the centrifugal compressor 1.

[0034] Furthermore, a flow meter 6 is installed between the drying chamber 5 and the humid air expander 4. The inlet and outlet of the humid air expander 4 are connected via a hand valve 16. The flow meter 6, the hand valve 16, and the gas-liquid separator 7 are connected in sequence. The outlet of the drying chamber 5 is connected to the inlet of the humid air expander 4 via the flow meter 6.

[0035] Furthermore, the drying filter 8 is connected to the heat exchange assembly and the centrifugal compressor 1 respectively via a three-way solenoid valve 9. The heat exchange assembly includes a heat exchanger 11 and a fan 10, with the fan 10 mounted on the side of the heat exchanger 11. The three-way solenoid valve 9 operates in two states. The first state is with ports a and b open and port c closed, in which case air flows through the heat exchanger 11 and the fan 10 is on. In this state, the inlet air temperature of the centrifugal compressor 1 can be brought closer to the ambient temperature. The second state is with ports a and c open and port b closed, in which case air flows directly into the centrifugal compressor 1 without passing through the heat exchanger 11.

[0036] Furthermore, a first temperature sensor is provided between the dryer filter 8 and the three-way solenoid valve 9, and a second temperature sensor is provided between the heat exchange assembly and the centrifugal compressor 1. The first temperature sensor is located at the outlet 82 of the regenerable dryer filter 8, and the second temperature sensor is located at the inlet of the centrifugal compressor 1.

[0037] Furthermore, a solenoid valve 13 is provided between the drying filter 8 and the drying chamber 5, and a thermometer 12 is provided between the solenoid valve 13 and the drying filter 8.

[0038] Furthermore, the dryer filter 8 includes a regeneration circuit inlet 83 and a regeneration circuit outlet 84, with the regeneration circuit inlet 83 connected to the solenoid valve 13. The inlet of the centrifugal compressor 1 is connected to the outlet of the heat exchanger 11 and port c of the three-way solenoid valve 9, respectively, and the outlet of the centrifugal compressor 1 is connected to the inlet of the drying chamber 5 and the solenoid valve 13, respectively. The regeneration circuit outlet 84 of the regenerable adsorption dryer filter 8 is in communication with the environment.

[0039] Furthermore, the gas-liquid separator 7 includes an air-side outlet 72 and a drain outlet 71. The air-side outlet 72 is connected to the dryer filter 8. The air-side outlet 72 is connected to the inlet 81 of the regenerable adsorption dryer filter 8, and the drain outlet 71 of the gas-liquid separator is in communication with the environment. The outlet 82 of the regenerable adsorption dryer filter 8 is connected to port a of the three-way solenoid valve 9, and port b of the three-way solenoid valve 9 is connected to the inlet of the heat exchanger 11.

[0040] Furthermore, the regenerable adsorption dryer filter 8 has a regenerable function. When the regenerable adsorption dryer filter 8 needs to be regenerated, during the operation of the centrifugal compressor 1, the solenoid valve 13 is opened, and high-temperature air flows into the regeneration circuit inlet 83 of the regenerable adsorption dryer filter 8, causing the desiccant to regenerate. The type of desiccant in the regenerable adsorption dryer filter 8 can be set as potassium carbonate, silica gel, alumina, or molecular sieve, depending on the temperature of the air being processed.

[0041] Example

[0042] Under the control of the frequency converter 15, the electric motor 3 drives the oil-free centrifugal air compressor 1 to rotate. The low-temperature, low-pressure air in the system is compressed by the oil-free centrifugal air compressor 1, resulting in increased temperature and pressure. At this time, the solenoid valve 13 is closed in the operating mode. All the air flows into the drying chamber 5 to dry the items. When the high-temperature, high-pressure air flows out of the drying chamber 5, the temperature decreases slightly, the pressure remains almost unchanged, and the humidity increases significantly. After passing through the flow meter 6 to measure the volumetric flow rate, the high-temperature, high-pressure, and high-humidity air flows into the wet air expander 4 to expand and perform work. Since the wet air expander 4 is connected to the centrifugal compressor 1 via the main shaft 2, the expansion work recovered by the wet air expander 4 provides part of the compression work for the centrifugal compressor 1, while the remaining compression work is provided by the electric motor. Therefore, due to the recovery of the internal and potential energy of the air by the wet air expander 4, the energy efficiency of the system is significantly improved.

[0043] The low-temperature, low-pressure, high-humidity air flowing out of the humid air expander 4 passes through the gas-liquid separator 7. The liquid water is discharged from the system through the drain outlet 71, while the high-humidity air flows into the regenerable adsorption dryer filter 8 through the air-side outlet 72 of the gas-liquid separator 7. The dried air flows out from the outlet 82 of the regenerable adsorption dryer filter 8, and after being measured by the first temperature sensor, it flows into the inlet a of the three-way solenoid valve 9. At this time, the second temperature sensor at the inlet of the centrifugal compressor 1, the ambient temperature gauge 12, and the temperature and humidity sensor 52 in the drying chamber 5 are all in working condition.

[0044] When the target drying temperature of the drying chamber 5 is set, such as 200℃, during the initial operation of the air source heat pump system of this invention, the temperature measured by the temperature and humidity sensor 52 in the drying chamber 5 will be lower than 200℃. Simultaneously, the system compares the measured values ​​of the first temperature sensor and the ambient thermometer 12. When the temperature measured by the first temperature sensor is lower than the ambient temperature, ports a and b of the three-way solenoid valve 9 open, port c closes, the fan 10 operates, and the manual valve 16 opens. At this time, the air flowing from the outlet 82 of the regenerable adsorption dryer filter 8 flows through the three-way solenoid valve 9 and into the heat exchanger 11. The air absorbs heat from the environment and then enters the compressor. After multiple cycles, the temperature inside the drying chamber will gradually increase. During this process, when the temperature measured by the first temperature sensor is higher than the ambient temperature, ports a and c of the three-way solenoid valve 9 open, port b closes, the fan 10 stops operating, and the air flowing from the outlet 82 of the regenerable adsorption dryer filter 8 flows directly into the compressor. After several cycles, the temperature inside the drying oven will eventually reach the target temperature of 200℃. However, as the cycle continues, the temperature inside the drying oven will continue to rise. At this point, the hand valve 16 is gradually closed, and the speed of the compressor 1 is slightly reduced or increased by the frequency converter 14 until the target temperature of the drying oven is stabilized at 200℃. This completes the entire working cycle.

[0045] The regeneration mode of an air-source heat pump system with a drying function described in this application is as follows:

[0046] The aforementioned air-source heat pump system with a drying function includes a regenerable adsorption dryer filter 8. When the desiccant's moisture absorption capacity in the regenerable adsorption dryer filter 8 significantly decreases, it should be regenerated. This is achieved by opening the solenoid valve 13 while the centrifugal compressor 1 is operating. High-temperature air then flows into the regeneration circuit 83 of the regenerable adsorption dryer filter 8, regenerating the desiccant. After regeneration, the solenoid valve 13 is closed. The type of desiccant in the regenerable adsorption dryer filter 8 can be potassium carbonate, silica gel, alumina, or molecular sieve, depending on the temperature of the air being processed.

[0047] Although this application has been described above with reference to specific embodiments, those skilled in the art will understand that many modifications can be made to the configurations and details disclosed in this application within the principles and scope of the disclosure. The scope of protection of this application is determined by the appended claims, and the claims are intended to cover all modifications included in the literal meaning or scope of equivalents of the technical features in the claims.

Claims

1. An air source heat pump system, characterized by: Including centrifugal compressor, drying box, wet air expander, gas-liquid separator, drying filter and heat exchange assembly connected in turn, the drying filter is connected with the centrifugal compressor, the heat exchange assembly is connected with the centrifugal compressor, the drying box is connected with the drying filter, the centrifugal compressor is connected with the wet air expander through the main shaft, the drying box is provided with indicator light, and the indicator light shows the air state by different colors; The drying box and the wet air expander are provided with a flow meter, the inlet and outlet of the wet air expander are connected through a hand valve, and the flow meter, the hand valve and the gas-liquid separator are connected in turn; The drying filter is connected with the heat exchange assembly and the centrifugal compressor through a three-way electromagnetic valve respectively; A first temperature sensor is arranged between the drying filter and the three-way electromagnetic valve; An electromagnetic valve is arranged between the drying filter and the drying box, and a thermometer is arranged between the electromagnetic valve and the drying filter.

2. The air source heat pump system of claim 1, wherein: A pressure sensor and a temperature and humidity sensor are arranged in the drying box, the pressure sensor is connected with a frequency conversion controller, the temperature and humidity sensor is connected with the frequency conversion controller, the frequency conversion controller is connected with a frequency converter, an electric motor is arranged outside the main shaft, the electric motor is connected with the centrifugal compressor, and the frequency converter is connected with the electric motor.

3. The air source heat pump system of claim 1, wherein: A second temperature sensor is arranged between the heat exchange assembly and the centrifugal compressor.

4. The air source heat pump system of claim 1, wherein: The heat exchange assembly comprises a heat exchanger and a fan.

5. The air source heat pump system of claim 1, wherein: The drying filter comprises a regeneration circuit inlet and a regeneration circuit outlet, and the regeneration circuit inlet is connected with the electromagnetic valve.

6. The air source heat pump system of claim 5, wherein: The gas-liquid separator comprises an air side outlet and a drain port, and the air side outlet is connected with the drying filter.

7. The air source heat pump system of any of claims 1-6, wherein: The drying filter is a renewable adsorption type drying filter, a drying agent is arranged in the drying filter, and the drying agent is potassium carbonate, silica gel, aluminum oxide or molecular sieve.

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