An open air source heat pump drying unit performance testing device and testing method thereof

Abstract

The application belongs to the technical field of equipment performance testing, and specifically discloses an open air source heat pump drying unit performance testing device and a testing method thereof. The device comprises a drying unit to be tested; the drying unit to be tested is placed in a enthalpy difference laboratory; the device further comprises an air inlet heating assembly for providing an experimental temperature field for the drying unit to be tested, and an air outlet cooling assembly for cooling the air outlet of the drying unit to be tested; one end of the air inlet heating assembly is connected with a ventilation pipe outside the enthalpy difference laboratory, and the other end is connected with an air inlet of the drying unit to be tested; one end of the air outlet cooling assembly is connected with an air outlet of the drying unit to be tested, and the other end is connected with an air tunnel in the enthalpy difference laboratory; an air guide fan is arranged in the air tunnel. The device has a simple structure, and can meet the performance testing of the open drying unit and ensure the safety of the testing environment.

Description

Technical Field

[0001] This invention belongs to the field of equipment performance testing technology, specifically relating to a performance testing device and testing method for an open-type air source heat pump dryer unit. Background Technology

[0002] An open-type air source heat pump dryer, or simply an open-type dryer unit, is the heat source unit of a drying device that uses an air source heat pump to heat air for dehumidification. It is widely used in industries such as wood, grain, food, pharmaceuticals, ceramics, aquatic products, textiles, chemicals, papermaking, tea, and sludge treatment, playing a crucial role in the heat and humidity treatment of air. Its performance parameters, such as heat supply and dehumidification efficiency, directly affect the quality of the materials.

[0003] Open-type air dryers are classified into high-temperature and medium-temperature types based on their outlet dry-bulb temperature. Before leaving the factory, these dryers require performance testing or third-party testing. However, currently, there are no performance testing devices available for open-type air dryers on the market. The NB / T10156-2019 "General Technical Specification for Air Source Heat Pump Dryers" stipulates that the performance testing method for open-type air dryers should be based on the enthalpy difference test device in Appendix A of GB / T 17758-2010 "Unitary Air Conditioners". Considering the operating mode of open-type air dryers, using a loop-type air enthalpy difference method to test their performance is more scientific and reasonable. However, currently, most domestic manufacturers and testing institutions use wind tunnel-type enthalpy difference test laboratories. High-temperature open-type dryers have outlet air temperatures exceeding 70℃, while medium-temperature open-type dryers reach over 55℃. Correspondingly, return air temperatures are also high, and in some specialized industries, even higher outlet air temperatures are required. However, the high-temperature environment of conventional wind tunnel enthalpy difference test chambers is difficult to achieve, and such environments pose safety hazards such as fires to testing equipment. Furthermore, the high-temperature environment in test chambers can easily damage the health of testing personnel. Therefore, a solution is urgently needed. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a performance testing device and method for open-type air source heat pump dryers. This device is not only simple in structure, but also ensures the safety of the testing environment while meeting the performance testing requirements of open-type dryers.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A performance testing device and method for an open-type air source heat pump dryer unit, characterized in that it includes a dryer unit under test; the dryer unit under test is placed in an enthalpy difference laboratory; it also includes an inlet heating component to provide an experimental temperature field for the dryer unit under test, and an outlet cooling component to cool the outlet air of the dryer unit under test; the inlet heating component is connected to a ventilation pipe outside the enthalpy difference laboratory and the air inlet of the dryer unit under test; the outlet cooling component is connected to the air outlet of the dryer unit under test and a wind tunnel inside the enthalpy difference laboratory; the wind tunnel is equipped with an induced draft fan.

[0007] Preferably, the air inlet heating assembly includes a heating flow equalization box; the heating flow equalization box is installed inside the enthalpy difference laboratory, one end is connected to a ventilation duct outside the enthalpy difference laboratory, and the other end is connected to the air inlet of the dryer unit to be tested. A first temperature sensor is installed at the connection between the heating flow equalization box and the ventilation duct, and a second temperature sensor is installed at the connection between the heating flow equalization box and the air inlet of the dryer unit to be tested. An electric heating grid is installed between the first temperature sensor and the second temperature sensor. The electric heating grid heats the airflow passing through the heating flow equalization box.

[0008] Preferably, the air cooling assembly includes a horizontally arranged cooling and flow equalization box; one end of the cooling and flow equalization box is connected to the air outlet of the dryer unit under test, and the other end is connected to the wind tunnel, and a third temperature sensor is provided at the connection between the cooling and flow equalization box and the air outlet of the dryer unit under test; a cooling water coil is provided at the connection between the cooling and flow equalization box and the wind tunnel; the cooling water coil cools the air flowing through the cooling and flow equalization box according to the temperature value of the third temperature sensor.

[0009] Preferably, it also includes a heat-insulating air duct; the heat-insulating air duct is set at the connection between the cooling flow equalization box and the air outlet of the dryer unit to be tested, one end of which is connected to the air outlet of the dryer unit to be tested, and the other end is connected to the cooling flow equalization box, so as to guide the hot air in the air outlet of the dryer unit to be tested into the cooling flow equalization box.

[0010] Preferably, it also includes a first flow equalization net; the first flow equalization net is installed in the heating flow equalization box and is located between the electric heating net and the second temperature sensor, so as to evenly introduce the heated hot air in the heating flow equalization box into the air inlet of the dryer unit to be tested.

[0011] Preferably, it also includes a second flow equalization net; the second flow equalization net is installed in the cooling flow equalization box and is located between the third temperature sensor and the air outlet of the dryer unit under test, so as to uniformly guide the hot air at the air outlet of the dryer unit under test to the cooling water coil.

[0012] Preferably, it also includes a constant temperature water tank; the constant temperature water tank is connected to the outlet of the cooling water coil, and a water pump with adjustable power is arranged in the constant temperature water tank; the water pump is connected to the inlet of the cooling water coil, and delivers water from the constant temperature water tank to the cooling water coil.

[0013] Preferably, it also includes a wet-bulb and dry-bulb temperature sensor; the wet-bulb and dry-bulb temperature sensor is installed in the enthalpy difference laboratory to monitor the temperature in the enthalpy difference laboratory.

[0014] Preferably, it also includes a computer; the computer is electrically connected to the electric heating grid, the first temperature sensor, the second temperature sensor, the third temperature sensor, the water pump, the dryer unit to be tested, the induced draft fan, and the wet and dry bulb temperature sensors.

[0015] Preferably, the specific operation steps are as follows:

[0016] S1: Install the dryer unit to be tested in the enthalpy difference laboratory. Connect the air inlet of the dryer unit to the heating flow equalization box and the air outlet to the heat-insulated air duct. Connect the dryer unit to the computer.

[0017] S2: Set the standard values ​​of the parameters to be measured for the dryer unit under test on the computer, and at the same time start the induced draft fan and the dryer unit under test in the wind tunnel.

[0018] The computer compares and analyzes the data measured by the first and second temperature sensors with standard values, and then adjusts the electric heating grid to heat the air in the heating and equalization chamber, so that the temperature field in the heating and equalization chamber and the temperature of the air outlet at the dryer unit under test meet the standard requirements.

[0019] The computer adjusts the temperature of the constant temperature water tank based on the values ​​measured by the third temperature sensor, and at the same time controls the water pump to input cooling water from the constant temperature water tank into the cooling water coil, thereby reducing the outlet air temperature of the dryer unit under test.

[0020] S3: The computer controls the operating power of the induced draft fan to keep the air volume and static pressure along the airflow direction stable, ensuring that the test values ​​of the second temperature sensor at the air inlet of the dryer under test and the test values ​​of the third temperature sensor at the air outlet of the dryer under test are both stable.

[0021] S4: After all required parameters have been stable for more than 15 minutes, the computer collects test data from all test cycles within 35 minutes, and calculates the performance parameters of the dryer unit (10) under test by averaging all data within 35 minutes.

[0022] The formula for calculating the heat generation using the wind tunnel enthalpy difference method is as follows:

[0023]

[0024] In the above formula: Q is the heating capacity of the dryer unit under test (kW), and ρ is the average density of the air flowing through the dryer unit under test (kg / m³). 3), d is the moisture content of the air flowing through the dryer unit under test (kg / kg dry air). L is the air volume flowing through the dryer unit under test (m3 / s), C pa The average isobaric specific heat of the air flowing through the dryer unit under test is given as (kJ / (kg·℃)). t1 and t2 are the air temperatures (℃) of the second and third temperature sensors at the inlet and outlet of the dryer unit under test, respectively.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] (1) This invention involves setting up a heating and equalization chamber in a wind tunnel enthalpy difference test chamber. One end of the heating and equalization chamber is connected to a ventilation duct outside the enthalpy difference laboratory, and the other end is connected to the air inlet of the dryer unit under test. A first temperature sensor is installed at the connection between the heating and equalization chamber and the ventilation duct, and a second temperature sensor is installed at the connection between the heating and equalization chamber and the air inlet of the dryer unit under test. An electric heating grid is installed between the first and second temperature sensors. When the temperature field required for the performance test of the dryer unit under test is high, the temperature of the air entering the ventilation duct outside the enthalpy difference laboratory is transmitted to the controller terminal through the first temperature sensor. The controller terminal activates the electric heating grid to heat the airflow flowing through the heating and equalization chamber according to the set standard value until the temperature field inside the heating and equalization chamber measured by the second temperature sensor meets the standard test temperature. This setup not only allows operators to precisely control the temperature field for testing the performance of the dryer under test, but also isolates the temperature field required by the dryer under test in the enthalpy difference laboratory from the temperature field of the laboratory itself. This ensures that the temperature field in the enthalpy difference laboratory remains at room temperature, protecting the instruments and operators from the high-temperature field required for testing the performance of the dryer under test. This improves both experimental efficiency and safety.

[0027] (2) This invention sets up a cooling and equalization chamber in the enthalpy difference laboratory; one end of the cooling and equalization chamber is connected to the air outlet of the dryer unit under test, and the other end is connected to the wind tunnel, and a third temperature sensor is set at the connection between the cooling and equalization chamber and the air outlet of the dryer unit under test; and a cooling water coil is set at the connection between the cooling and equalization chamber and the wind tunnel. When the third temperature sensor transmits the air outlet temperature of the dryer unit under test to the control terminal, the control terminal controls the water flow rate in the cooling water coil according to the temperature value, thereby achieving a faster reduction in the airflow temperature in the cooling and equalization chamber. Through this setting, the airflow temperature entering the wind tunnel is effectively reduced, so that the temperature of the airflow entering the wind tunnel from the cooling and equalization chamber into the enthalpy difference laboratory is within a safe range and will not affect the temperature field in the enthalpy difference laboratory. This enables the performance testing of high-temperature and medium-temperature open dryer units in a conventional wind tunnel enthalpy difference test chamber, reducing experimental costs while ensuring the safety of the performance testing of high-temperature and medium-temperature open dryer units.

[0028] (3) By setting a first flow equalization net in the heating flow equalization box, the airflow in the heating flow equalization box can be uniformly introduced into the air inlet of the dryer unit under test, thereby ensuring the stability of the temperature field required for the performance test of the dryer unit under test and improving the accuracy of the final result of the dryer unit performance test.

[0029] (4) The present invention sets a second flow equalization net in the cooling flow equalization box, and the second flow equalization net is located between the third temperature sensor and the air outlet of the dryer unit under test, so that the air outlet of the dryer unit under test can be uniformly guided to the cooling water coil, so that the temperature of the airflow can be quickly reduced by the cooling water coil, thereby improving the cooling efficiency.

[0030] (5) This invention incorporates a constant-temperature water tank connected to the outlet of the cooling water coil, and a power-adjustable water pump installed in the tank, connected to the inlet of the cooling water coil. This configuration ensures that the water in the cooling water coil remains at a low temperature and also enables water circulation. Furthermore, the adjustable power of the water pump allows for controllable cooling of the cooling water coil, thus improving its cooling effect.

[0031] (6) The present invention provides a heat-insulating air duct at the connection between the cooling flow equalization box and the air outlet of the dryer under test. Since the heat-insulating air duct has a good heat insulation effect, the air outlet of the dryer under test will not generate heat conduction during the process of being transported to the cooling flow equalization box, thereby reducing the influence of the air outlet of the dryer under test on the temperature field in the enthalpy difference laboratory and improving the safety of the temperature field in the enthalpy difference laboratory.

[0032] (7) This invention improves the safety of operators and instruments in the enthalpy difference laboratory by setting up dry and wet bulb temperature sensors to monitor the temperature in the enthalpy difference laboratory.

[0033] (8) This invention incorporates a computer, which is electrically connected to the electric heating grid, the first temperature sensor, the second temperature sensor, the third temperature sensor, the water pump, the dryer unit under test, the induced draft fan, and the wet-bulb and dry-bulb temperature sensors. This setup eliminates the need to modify the wind tunnel enthalpy difference test chamber. The technical parameters of the dryer unit under test, collected and measured by each sensor, are transmitted via communication to the computer equipped with an open-type dryer unit performance testing program. The computer automatically completes the detection and data processing, providing data support for improving the performance testing of the dryer unit under test, while also enhancing the accuracy and efficiency of the experimental results.

[0034] (9) The device designed in this invention has a simple structure, is easy to install and operate. It can automatically measure the performance parameters of the dryer unit under test by simply connecting the heating flow equalization box and the cooling flow equalization box to the dryer unit under test through the heat-insulated air duct, thereby improving the experimental efficiency. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of the present invention;

[0036] The actual correspondence between the reference numerals and component names in this invention is as follows:

[0037] 10 - Dryer unit under test; 20 - Enthalpy difference laboratory; 21 - Dry and wet bulb temperature sensor

[0038] 31-Ventilation duct; 311-First temperature sensor; 32-Insulated air duct

[0039] 40-Heating Flow Equalization Box

[0040] 41-Electric heating mesh; 42-First current equalization mesh; 43-Second temperature sensor

[0041] 50 - Cooling and Flow Equalization Box; 51 - Second Flow Equalization Grid; 52 - Third Temperature Sensor

[0042] 53-Cooling water coil 60-Wind tunnel Detailed Implementation

[0043] 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.

[0044] Example 1

[0045] like Figure 1 The device shown is an open-type air source heat pump dryer performance testing device, characterized in that it includes a dryer unit 10 to be tested installed in an enthalpy difference laboratory 20. The air inlet of the dryer unit 10 is connected to a ventilation duct 31 outside the enthalpy difference laboratory 20 through an air inlet heating component; the air outlet of the dryer unit 10 is connected to a wind tunnel 60 inside the enthalpy difference laboratory 20 through an air outlet cooling component, and an induced draft fan is installed in the wind tunnel 60. When the induced draft fan in the wind tunnel 60 is turned on, the airflow enters the air inlet heating component along the ventilation duct 31, and the air inlet heating component heats the airflow to the temperature of the experimental temperature field required for the performance testing of the dryer unit 10; while the temperature of the air outlet at the dryer unit 10 is cooled by the air outlet cooling component before entering the wind tunnel 60.

[0046] The air inlet heating assembly consists of a heating flow equalization box 40, a first temperature sensor 311, a first flow equalization net 42, a second temperature sensor 43, and an electric heating net 41. The heating flow equalization box 40 is installed inside the enthalpy difference laboratory 20, with one end connected to the ventilation duct 31 outside the enthalpy difference laboratory 20 and the other end connected to the air inlet of the dryer unit 10 under test. The first temperature sensor 311 is located at the connection between the heating flow equalization box 40 and the ventilation duct 31, and the second temperature sensor 43 is located at the connection between the heating flow equalization box 40 and the air inlet of the dryer unit 10 under test. The electric heating net 41 is located between the first temperature sensor 311 and the second temperature sensor 43, and heats the airflow flowing through the heating flow equalization box 40. The first flow equalization net 42 is located between the electric heating net 41 and the second temperature sensor 43, and evenly guides the heated air in the heating flow equalization box 40 into the air inlet of the dryer unit 10 under test.

[0047] When the temperature field required for the performance test of the dryer unit 10 is high, the temperature of the air entering through the ventilation duct 31 outside the enthalpy difference laboratory is transmitted to the controller terminal via the first temperature sensor 311. The control terminal then activates the electric heating grid 41 to heat the airflow passing through the heating equalization box 40 according to the set standard value, until the temperature field inside the heating equalization box 40 is measured by the second temperature sensor 43 to meet the standard test temperature. This setup not only allows operators to accurately control the temperature field for the performance test of the dryer unit 10, but also isolates the temperature field required by the dryer unit 10 within the enthalpy difference laboratory 20 from the temperature field within the laboratory itself. This ensures that the temperature field within the enthalpy difference laboratory 20 remains at room temperature, protecting the instruments and operators from the temperature field required for the performance test of the dryer unit 10. This improves both experimental efficiency and safety.

[0048] The air cooling assembly consists of a cooling and equalization box 50, a third temperature sensor 52, a cooling water coil 53, and a second equalization net 51. One end of the cooling and equalization box 50 is connected to the air outlet of the dryer unit 10 under test, and the other end is connected to the wind tunnel 60. The third temperature sensor 52 is located at the connection between the cooling and equalization box 50 and the air outlet of the dryer unit 10 under test, and the cooling water coil 53 is located at the connection between the cooling and equalization box 50 and the wind tunnel 60. The second equalization net 51 is installed in the cooling and equalization box 50 and is located between the third temperature sensor 52 and the air outlet of the dryer unit 10 under test, uniformly guiding the hot air from the air outlet of the dryer unit 10 under test to the cooling water coil 53. The cooling water coil 53 cools the air flowing through the cooling and equalization box 50 according to the temperature value of the third temperature sensor 52.

[0049] When the third temperature sensor 52 transmits the outlet air temperature of the dryer unit 10 under test to the control terminal, the control terminal controls the water flow rate in the cooling water coil 53 according to the temperature value, thereby reducing the airflow temperature in the cooling equalization box 50 at a relatively fast speed. This setting effectively reduces the airflow temperature entering the wind tunnel 60, ensuring that the temperature of the airflow entering the enthalpy difference laboratory 20 from the cooling equalization box 50 is within a safe range and will not affect the temperature field within the enthalpy difference laboratory 20. This enables performance testing of high-temperature and medium-temperature open-type dryers in a conventional wind tunnel enthalpy difference test chamber, reducing experimental costs while ensuring the safety of performance testing of high-temperature and medium-temperature open-type dryers.

[0050] It also includes a constant temperature water tank; the constant temperature water tank is connected to the outlet of the cooling water coil 53, and a water pump with adjustable power is installed in the constant temperature water tank; the water pump is connected to the inlet of the cooling water coil 53, and delivers water from the constant temperature water tank to the cooling water coil 53.

[0051] It also includes a heat-insulating air duct 32; the heat-insulating air duct 32 is set at the connection between the cooling flow equalization box 50 and the air outlet of the dryer unit 10 to be tested, one end of which is connected to the air outlet of the dryer unit 10 to be tested, and the other end is connected to the cooling flow equalization box 50, so as to introduce the hot air in the air outlet of the dryer unit 10 to be tested into the cooling flow equalization box 50.

[0052] The cooling flow equalization box 50 is arranged horizontally in the enthalpy difference laboratory to prevent the condensate generated by the airflow cooling in the cooling flow equalization box 50 from flowing back into the heat-insulated air duct 32 and ultimately damaging the machine.

[0053] It also includes a wet-bulb and dry-bulb temperature sensor 21; the wet-bulb and dry-bulb temperature sensor 21 is installed in the enthalpy difference laboratory 20 to monitor the temperature in the enthalpy difference laboratory 20.

[0054] It also includes a computer; the computer is electrically connected to the electric heating grid 41, the first temperature sensor 311, the second temperature sensor 43, the third temperature sensor 52, the water pump, the dryer unit under test 10, the induced draft fan, and the wet and dry bulb temperature sensor 21.

[0055] Example 2

[0056] The specific operating steps of a performance testing method for an open-type air source heat pump dryer are as follows:

[0057] S1: Install the dryer unit 10 to be tested into the enthalpy difference laboratory 20. The air inlet of the dryer unit 10 to be tested is connected to the heating flow equalization box 40, and the air outlet is connected to the heat insulation air duct 32. Connect the dryer unit 10 to the computer.

[0058] S2: Set the standard values ​​of the parameters to be measured for the dryer unit 10 under test on the computer, and at the same time start the induced draft fan in the wind tunnel 60 and the dryer unit 10 under test.

[0059] The computer compares and analyzes the data measured by the first temperature sensor 311 and the second temperature sensor 43 with the standard values, and then adjusts the electric heating grid 41 to heat the air in the heating equalization box 40, so that the temperature field in the heating equalization box 40 and the temperature of the air outlet at the air outlet of the dryer unit 10 under test meet the standard requirements.

[0060] The computer adjusts the temperature of the constant temperature water tank based on the value measured by the third temperature sensor 52, and at the same time controls the water pump to input the cooling water in the constant temperature water tank into the cooling water coil 53, thereby reducing the outlet air temperature of the dryer unit 10 under test.

[0061] S3: The computer controls the operating power of the induced draft fan to keep the air volume and static pressure along the airflow direction stable, ensuring that the test values ​​of the second temperature sensor 43 at the air inlet of the dryer unit 10 under test and the test values ​​of the third temperature sensor 52 at the air outlet of the dryer unit 10 under test are both stable.

[0062] S4: After all required parameters have been stable for more than 15 minutes, the computer collects test data from all test cycles within 35 minutes, and calculates the performance parameters of the dryer unit (10) under test by averaging all data within 35 minutes.

[0063] The formula for calculating the heat generation using the wind tunnel enthalpy difference method is as follows:

[0064]

[0065] In the above formula: Q is the heating capacity of the dryer unit 10 under test (kW), and ρ is the density of the air inside the enthalpy difference laboratory 20 (kg / m³). 3 ), d is the moisture content of the air in the enthalpy difference laboratory 20 (kg / kg dry air). L is the air volume in the wind tunnel 60 (m³ / kg dry air). 3 / s), C pa The average isobaric specific heat of the air flowing through the dryer unit 10 under test is given as kJ / (kg·℃) and t1 and t2 are the air temperatures (℃) at the inlet and outlet of the dryer unit 10, respectively, measured by the second temperature sensor 43 and the third temperature sensor 52.

[0066] As can be seen from the above method, the device designed in this invention has a simple structure, is easy to install, and is convenient to operate. It can automatically measure the performance parameters of the dryer unit 10 by simply connecting the heating flow equalization box 40 and the cooling flow equalization box 50 to the dryer unit 10 under test through the heat-insulated air duct, thereby improving the experimental efficiency.

[0067] Of course, those skilled in the art will recognize that the present invention is not limited to the details of the exemplary embodiments described above, but also includes the same or similar structures that can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0068] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. Technical aspects, shapes, and structures not described in detail in this invention are all well-known technologies.

Claims

1. A performance testing device for an open-type air source heat pump dryer unit, characterized in that, The test includes a dryer unit (10) to be tested, which is placed inside an enthalpy difference laboratory (20). It also includes an inlet heating assembly that provides an experimental temperature field for the dryer unit (10), and an outlet cooling assembly that cools the outlet air of the dryer unit (10). The inlet heating assembly connects a ventilation pipe (31) outside the enthalpy difference laboratory (20) to the air inlet of the dryer unit (10). The outlet cooling assembly connects the air outlet of the dryer unit (10) to a wind tunnel (60) inside the enthalpy difference laboratory (20). An induced draft fan is installed in the wind tunnel (60). The air inlet heating assembly includes a heating flow equalization box (40); the heating flow equalization box (40) is installed inside the enthalpy difference laboratory (20), one end of which is connected to the ventilation pipe (31) outside the enthalpy difference laboratory (20), and the other end is connected to the air inlet of the dryer unit (10) to be tested. A first temperature sensor (311) is provided at the connection between the heating flow equalization box (40) and the ventilation pipe (31), and a second temperature sensor (43) is provided at the connection between the heating flow equalization box (40) and the air inlet of the dryer unit (10) to be tested. An electric heating grid (41) is provided between the first temperature sensor (311) and the second temperature sensor (43). The electric heating grid (41) heats the airflow flowing through the heating flow equalization box (40). The air cooling assembly includes a horizontally arranged cooling and equalization box (50); one end of the cooling and equalization box (50) is connected to the air outlet of the dryer unit (10) under test, and the other end is connected to the wind tunnel (60), and a third temperature sensor (52) is provided at the connection between the cooling and equalization box (50) and the air outlet of the dryer unit (10) under test; a cooling water coil (53) is provided at the connection between the cooling and equalization box (50) and the wind tunnel (60); the cooling water coil (53) cools the air flowing through the cooling and equalization box (50) according to the temperature value of the third temperature sensor (52); It also includes a first flow equalization net (42); the first flow equalization net (42) is installed in the heating flow equalization box (40) and located between the electric heating net (41) and the second temperature sensor (43), so as to uniformly introduce the heated hot air in the heating flow equalization box (40) into the air inlet of the dryer unit (10) to be tested.

2. The performance testing device for an open-type air source heat pump dryer unit according to claim 1, characterized in that, It also includes a heat-insulating air duct (32); the heat-insulating air duct (32) is set at the connection between the cooling flow equalization box (50) and the air outlet of the dryer unit (10) to be tested, one end of which is connected to the air outlet of the dryer unit (10) to be tested, and the other end of which is connected to the cooling flow equalization box (50) to introduce the hot air in the air outlet of the dryer unit (10) to be tested into the cooling flow equalization box (50).

3. The performance testing device for an open-type air source heat pump dryer unit according to claim 2, characterized in that, It also includes a second flow equalization net (51); the second flow equalization net (51) is installed in the cooling flow equalization box (50) and located between the third temperature sensor (52) and the air outlet of the dryer unit (10) under test, so as to uniformly guide the hot air at the air outlet of the dryer unit (10) under test to the cooling water coil (53).

4. The performance testing device for an open-type air source heat pump dryer unit according to claim 3, characterized in that, It also includes a constant temperature water tank; the constant temperature water tank is connected to the outlet of the cooling water coil (53), and a water pump with adjustable power is arranged in the constant temperature water tank; the water pump is connected to the inlet of the cooling water coil (53) to transport the water in the constant temperature water tank to the cooling water coil (53).

5. The performance testing device for an open-type air source heat pump dryer unit according to claim 4, characterized in that, It also includes a wet-bulb and dry-bulb temperature sensor (21); the wet-bulb and dry-bulb temperature sensor (21) is installed in the enthalpy difference laboratory (20) to monitor the temperature in the enthalpy difference laboratory (20).

6. The performance testing device for an open-type air source heat pump dryer unit according to claim 5, characterized in that, It also includes a computer; the computer is electrically connected to the electric heating grid (41), the first temperature sensor (311), the second temperature sensor (43), the third temperature sensor (52), the water pump, the dryer unit to be tested (10), the induced draft fan, and the wet and dry bulb temperature sensor (21).

7. A method for testing the performance of an open-type air-source heat pump dryer unit according to any one of claims 1-6, characterized in that, The specific steps are as follows: S1: Install the dryer unit (10) to be tested into the enthalpy difference laboratory (20). The air inlet of the dryer unit (10) to be tested is connected to the heating flow equalization box (40), and the air outlet is connected to the heat insulation air duct (32). Connect the dryer unit (10) to the computer. S2: Set the standard values ​​of the parameters to be measured for the dryer unit (10) under test on the computer, and at the same time start the induced draft fan in the wind tunnel (60) and the dryer unit (10) under test. The computer compares and analyzes the data measured by the first temperature sensor (311) and the second temperature sensor (43) with the standard values, and then adjusts the electric heating grid (41) to heat the air in the heating equalization box (40) so that the temperature field in the heating equalization box (40) and the temperature of the air outlet at the air outlet of the dryer unit (10) under test meet the standard requirements. The computer adjusts the temperature of the constant temperature water tank based on the value measured by the third temperature sensor (52), and at the same time controls the water pump to input the cooling water in the constant temperature water tank into the cooling water coil (53) to reduce the outlet air temperature of the dryer unit (10) under test. S3: The computer controls the operating power of the induced draft fan to keep the air volume and static pressure along the airflow direction stable, ensuring that the test values ​​of the second temperature sensor (43) at the air inlet of the dryer unit (10) under test and the test values ​​of the third temperature sensor (52) at the air outlet of the dryer unit (10) under test are both stable. S4: After all required parameters have been stable for more than 15 minutes, the computer collects test data from all test cycles within 35 minutes, and calculates the performance parameters of the dryer unit (10) under test by averaging all data within 35 minutes. The formula for calculating the heat generation using the wind tunnel enthalpy difference method is as follows: In the above formula: Q is the heating capacity (kW) of the dryer unit (10) under test, and ρ is the average density (kg / m³) of the air flowing through the dryer unit (10) under test. 3 ), d is the moisture content (kg / kg dry air) of the air flowing through the dryer unit (10) under test; L is the air volume (m³ / kg) flowing through the dryer unit (10) under test. 3 / s), C pa The average isobaric specific heat of the air flowing through the dryer unit (10) under test (kJ / (kg·℃)) is given. t1 and t2 are the air temperatures (℃) of the second temperature sensor (43) and the third temperature sensor (52) at the inlet and outlet of the dryer unit (10) under test, respectively.

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