Method for testing refrigerating capacity of vehicle-mounted refrigerating unit

Abstract

The present application relates to the technical field of refrigeration equipment performance test, and particularly relates to a kind of vehicle-mounted refrigeration unit refrigerating capacity test method, the method comprises: the evaporating side component of vehicle-mounted refrigeration unit is placed in the outdoor side of the air enthalpy method device of preset, and the air enthalpy method device outdoor side air inlet sampling rake is set to the air inlet of evaporator outside;Condenser air outlet air duct is set to the air outlet of the condenser of vehicle-mounted refrigeration unit;Condensing side component is placed in the indoor side, and the air inlet sampling rake of indoor side is set to the air inlet of condenser outside, and condenser air outlet air duct is connected into the air tunnel of air enthalpy method device;The outdoor side is set to low temperature and the indoor side is set to high temperature, measures condenser heating capacity and unit power data;Based on the principle of energy conservation, the refrigerating capacity of vehicle-mounted refrigeration unit is calculated by condenser heating capacity and unit power data.Such, the low-temperature measurement problem is avoided, and the test is more efficient, and the result is more accurate and reliable.

Description

Technical Field

[0001] This invention relates to the field of performance testing technology for refrigeration equipment, and specifically to a method for testing the cooling capacity of a vehicle-mounted refrigeration unit. Background Technology

[0002] A vehicle-mounted refrigeration unit is a mechanical refrigeration system used for temperature control of goods during transportation. It mainly includes a compressor, power unit, condenser assembly, evaporator assembly, refrigeration piping, and electrical and control systems. As a key cold source device in the express cold chain transportation process, the performance of the vehicle-mounted refrigeration unit directly affects the construction of a low-temperature environment during cold chain transportation. Its performance indicators are also important references for configuring refrigerated transport compartments and logistics insulation packaging. The vehicle-mounted refrigeration unit maintains an independent, stable, and precise low-temperature environment inside the compartment. The unit continuously generates cooling capacity through a refrigeration cycle. Its performance, especially the accuracy and reliability of its cooling capacity, directly determines whether it can quickly drop to the target temperature within a set time and under extreme conditions, strictly controlling temperature fluctuations inside the compartment within the allowable range. The cooling capacity of the refrigeration unit is also a core basis for the design and optimization of refrigerated truck systems. The volume of the compartment, the performance and thickness of the insulation material must be strictly matched to the rated cooling capacity of the unit. Insufficient capacity will lead to temperature control failure, while excessive capacity will result in wasted cost and energy.

[0003] Currently, the refrigeration and air conditioning industry has matured significantly in terms of existing technologies. The industry possesses a large number of air enthalpy measurement devices and has established standard devices for measuring refrigeration capacity, which can serve as the basic carrier for measuring the performance of vehicle-mounted refrigeration units. However, challenges such as low-temperature refrigeration capacity measurement and refrigeration capacity traceability still need to be addressed.

[0004] The air enthalpy method device is used to measure the refrigeration performance of air conditioners, with a suitable measurement temperature range above 0°C. This device uses wet-bulb and dry-bulb thermometers to measure the inlet and outlet air temperature and humidity parameters. For wet-bulb temperature measurement, a fully soaked gauze is required, with the bottom of the gauze completely immersed in the water cup of the sampler. If the air enthalpy method is used to directly measure the evaporator-side cooling capacity of a vehicle-mounted refrigeration unit, and the unit's return air temperature is 0°C, any drop in outlet air temperature below 0°C will cause the water cup of the outlet air sampler to freeze, making it impossible to measure outlet air humidity. However, according to the air enthalpy method calculation model, the wet-bulb temperature must be measured to calculate air moisture content and airflow.

[0005] In summary, the air enthalpy method cannot be directly applied to the testing of the cooling capacity of vehicle-mounted refrigeration units. Therefore, how to efficiently and accurately measure the cooling capacity of vehicle-mounted refrigeration units has become an urgent technical problem to be solved. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a method for testing the cooling capacity of an on-board refrigeration unit, so as to overcome the current problem that it is impossible to efficiently and accurately measure the cooling capacity of an on-board refrigeration unit.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This application provides a method for testing the cooling capacity of an on-board refrigeration unit, including:

[0009] The evaporator-side component of the vehicle-mounted refrigeration unit is placed on the outdoor side of the preset air enthalpy method device, and the air intake sampling rake on the outdoor side of the air enthalpy method device is set outside the air inlet of the evaporator; wherein, the evaporator-side component includes the evaporator;

[0010] A condenser outlet air duct is installed at the air outlet of the condenser of the vehicle-mounted refrigeration unit.

[0011] The condenser side component of the vehicle-mounted refrigeration unit is placed on the indoor side of the air enthalpy method device, and the air intake sampling rake of the indoor side of the air enthalpy method device is set outside the air inlet of the condenser, and the air outlet duct of the condenser is connected to the air tunnel of the air enthalpy method device.

[0012] The outdoor side was set to a low temperature and the indoor side to a high temperature, and the condenser heating capacity and unit power data were measured.

[0013] Based on the principle of energy conservation, the cooling capacity of the vehicle-mounted refrigeration unit is calculated using the condenser's heating capacity and the unit's power data.

[0014] Furthermore, in some embodiments of this application, the evaporator-side component of the vehicle-mounted refrigeration unit is disposed on the outdoor side of the preset air enthalpy method device, and the condenser-side component of the vehicle-mounted refrigeration unit is disposed on the indoor side of the air enthalpy method device, including:

[0015] For integrated vehicle-mounted refrigeration units, the vehicle-mounted refrigeration unit is installed on the middle partition wall of the air enthalpy method device, so that the evaporator side component of the vehicle-mounted refrigeration unit is located on the outdoor side of the air enthalpy method device, and the condenser side component is located on the indoor side of the air enthalpy method device.

[0016] For split-type vehicle-mounted refrigeration units, the evaporator of the vehicle-mounted refrigeration unit is placed on the outdoor side of the air enthalpy method device, and the condenser is placed on the indoor side of the air enthalpy method device.

[0017] Furthermore, in some embodiments of this application, it also includes:

[0018] A pressure tapping interface is provided at the center of each wall of the tooling in the air duct of the condenser outlet;

[0019] Connect the pressure tapping port to the external static pressure connecting pipe of the air enthalpy method device, and connect the pressure gauge to the external static pressure measuring machine of the air enthalpy method device through a preset short pipe;

[0020] The pressure tapping interface is located at a distance from the air outlet of the condenser that is twice the cross-sectional dimension of the outlet; the pressure tapping interface is sealed by a pressure quick connector; and the pre-set short pipe includes a PVC transparent flexible tube.

[0021] Furthermore, in some embodiments of this application, the duct fixture for the condenser outlet duct includes a heat insulation plate;

[0022] One end of the condenser outlet duct completely covers the condenser outlet, and the other end is connected to the air duct of the air enthalpy method device. The cross-sectional dimension of the condenser outlet duct is larger than the size of the condenser outlet.

[0023] Furthermore, in some embodiments of this application, the setting of the outdoor side to a low temperature and the indoor side to a high temperature, and the measurement of condenser heating capacity and unit power data, includes:

[0024] The indoor dry-bulb temperature of the air enthalpy method device is set to high temperature, and the outdoor dry-bulb temperature is set to low temperature.

[0025] The indoor and outdoor wet-bulb temperatures of the air enthalpy method device are not controlled.

[0026] Turn off the humidifiers on both the indoor and outdoor sides of the air enthalpy method device, install the wet bulb gauze at the air outlet on the indoor side, and turn on the nozzle of the enthalpy difference airflow measuring device of the air enthalpy method device.

[0027] Turn on the indoor and outdoor circulating fans, sampling fans, heaters, and refrigerators of the air enthalpy method device.

[0028] Furthermore, in some embodiments of this application, the wet-bulb gauze for the indoor air outlet includes:

[0029] The wet cloth gauze at the air outlet is brought into contact with the wet bulb of the indoor air outlet of the air enthalpy method device for heat exchange, and the wet bulb gauze is replaced based on a preset replacement time.

[0030] Furthermore, in some embodiments of this application, the nozzle of the enthalpy difference airflow measuring device of the air enthalpy method apparatus includes:

[0031] The number and diameter of nozzles to be opened are determined based on the airflow of the condenser of the vehicle-mounted refrigeration unit; and the nozzles of the enthalpy difference airflow measuring device are opened based on the number and diameter of nozzles to be opened.

[0032] Furthermore, in some embodiments of this application, the step of setting the outdoor side to a low temperature and the indoor side to a high temperature, and measuring the condenser heating capacity and unit power data, further includes:

[0033] After the outdoor side stabilizes at a preset low temperature and the indoor side stabilizes at a preset high temperature for a preset duration, multiple sets of condenser heating capacity and unit power data are collected using the preset air enthalpy method device test software; wherein, the unit power data includes compressor power consumption, evaporator fan power, and condenser fan power.

[0034] Furthermore, in some embodiments of this application, the calculation of the cooling capacity of the on-board refrigeration unit based on the condenser heating capacity and the unit power consumption includes:

[0035] The difference between the condenser's heating capacity and the unit's power consumption is taken as the cooling capacity of the vehicle-mounted refrigeration unit, wherein the unit's power consumption is the sum of the compressor's power consumption, the evaporator fan's power consumption, and the condenser fan's power consumption.

[0036] This invention relates to the field of refrigeration equipment performance testing technology, specifically to a method for testing the cooling capacity of a vehicle-mounted refrigeration unit. The method includes: placing the evaporator-side component of the vehicle-mounted refrigeration unit on the outdoor side of a pre-set air enthalpy method device, and setting the air intake sampling rake of the outdoor side of the air enthalpy method device outside the air inlet of the evaporator; setting a condenser outlet duct at the air outlet of the condenser of the vehicle-mounted refrigeration unit; placing the condenser-side component of the vehicle-mounted refrigeration unit on the indoor side of the air enthalpy method device, and setting the air intake sampling rake of the indoor side of the air enthalpy method device outside the air inlet of the condenser; and connecting the condenser outlet duct to the air tunnel of the air enthalpy method device; setting the outdoor side to a low temperature and the indoor side to a high temperature, and measuring the condenser heating capacity and unit power data; and calculating the cooling capacity of the vehicle-mounted refrigeration unit based on the principle of energy conservation using the condenser heating capacity and unit power data. This method avoids the difficulties of low-temperature measurement, making the test more efficient and the results more accurate and reliable. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a flowchart illustrating the method for testing the cooling capacity of an on-board refrigeration unit provided in an embodiment of the present invention;

[0039] Figure 2This is a schematic diagram of the model principle of the method for testing the cooling capacity of a vehicle-mounted refrigeration unit provided in an embodiment of the present invention;

[0040] Figure 3 This is a schematic diagram illustrating the actual testing principle of the vehicle-mounted refrigeration unit cooling capacity testing method provided in this embodiment of the invention;

[0041] Figure 4 This is a schematic diagram of the first test result of the vehicle-mounted refrigeration unit cooling capacity test method provided in this embodiment of the invention for third-party comparative testing;

[0042] Figure 5 This is a schematic diagram of the second test result of the vehicle-mounted refrigeration unit cooling capacity test method provided in this embodiment of the invention for third-party comparative testing;

[0043] Figure 6 This is a schematic diagram of the third test result of the vehicle-mounted refrigeration unit cooling capacity test method provided in this embodiment of the invention for third-party comparative testing. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0045] Figure 1 This is a flowchart illustrating the method for testing the cooling capacity of an on-board refrigeration unit according to an embodiment of the present invention. Please refer to [link / reference]. Figure 1 This embodiment may include the following steps:

[0046] S101. Place the evaporator side component of the vehicle-mounted refrigeration unit on the outdoor side of the preset air enthalpy method device, and set the air intake sampling rake of the outdoor side of the air enthalpy method device outside the air inlet of the evaporator.

[0047] Specifically, the evaporator-side components of the vehicle-mounted refrigeration unit, including the evaporator, are placed on the outdoor side of the air enthalpy method device, and the outdoor side air intake sampling rake is arranged outside the air inlet of the vehicle-mounted unit evaporator, and the air outlet of the evaporator is allowed to ventilate freely, while ensuring that there are no objects obstructing it within two meters.

[0048] S102. Install a condenser outlet duct at the air outlet of the condenser of the vehicle-mounted refrigeration unit.

[0049] Specifically, a duct is constructed for the condenser outlet, with a cross-sectional dimension larger than that of the condenser outlet to ensure unimpeded airflow, and potential air leakage points near the condenser outlet are sealed.

[0050] S103. Place the condenser side component of the vehicle-mounted refrigeration unit on the indoor side of the air enthalpy method device, set the air intake sampling rake of the indoor side of the air enthalpy method device outside the air inlet of the condenser, and connect the air outlet duct of the condenser to the air tunnel of the air enthalpy method device.

[0051] Specifically, the condenser-side components of the vehicle-mounted refrigeration unit are placed on the indoor side of the air enthalpy method device. The air intake sampling rake on the indoor side is arranged outside the air inlet of the vehicle-mounted unit's condenser, and the condenser's air outlet is completely covered by the air duct (i.e., the condenser air outlet air duct) and connected to the air tunnel of the air enthalpy method device. The air duct, condenser, and air tunnel are sealed and insulated.

[0052] S104. Set the outdoor side to low temperature and the indoor side to high temperature, and measure the condenser heating capacity and unit power data.

[0053] S105. Based on the principle of energy conservation, the cooling capacity of the vehicle-mounted refrigeration unit is calculated using the condenser heating capacity and unit power data.

[0054] Specifically, in practical applications, a baffle can be installed at the air outlet of the enthalpy difference airflow measuring device of the air enthalpy method device to prevent the airflow from the enthalpy difference airflow measuring device from blowing directly around the condenser of the vehicle-mounted refrigeration unit.

[0055] Then, any possible air leaks on the outdoor side of the air enthalpy method device are sealed to minimize water vapor penetration into the outdoor room (i.e., the outdoor side of the air enthalpy method device).

[0056] Based on this, the operating conditions of the vehicle-mounted refrigeration unit during testing were set to low indoor temperature and high outdoor temperature, maintaining a certain temperature difference between the indoor and outdoor sides, without controlling the ambient humidity. Independent, repeated measurements were then performed, and the unit's defrosting function was activated after each measurement. After defrosting, the unit re-entered operating mode.

[0057] It should be noted that during the measurement, the condenser heating capacity, air volume and unit power data of multiple vehicle-mounted units should be measured simultaneously. After the data stabilizes or after a certain period of testing, the test data should be selected. Alternatively, in some embodiments, new test data can be obtained after the operating conditions are determined to be stable based on the measurement data.

[0058] Based on this, and using the principle of energy conservation, the cooling capacity of the vehicle-mounted refrigeration unit is calculated using condenser heating capacity and unit power data. In this application, the cooling capacity of the vehicle-mounted refrigeration unit is defined as equal to the condenser-side heating capacity (i.e., condenser heating capacity) minus the unit's power consumption (total power consumption, including compressor power consumption, evaporator fan power, and condenser fan power).

[0059] Figure 2 This is a schematic diagram of the model principle of the test method for the cooling capacity of the vehicle-mounted refrigeration unit provided in the embodiment of the present invention. In order to obtain the cooling capacity of the vehicle-mounted refrigeration unit, it is necessary to eliminate unnecessary interference factors as much as possible. Therefore, this application adopts a simple measurement model as the model for measuring the cooling capacity of the vehicle-mounted refrigeration unit using the air enthalpy method. Through analysis, it can be seen that the evaporator side component of the vehicle-mounted refrigeration unit is placed in the low-temperature zone of the outdoor side of the air enthalpy method device, and the condenser side component of the vehicle-mounted refrigeration unit is placed in the high-temperature zone of the indoor side of the air enthalpy method device. The air enthalpy method device directly measures the heating capacity and the power consumption data of the vehicle-mounted refrigeration unit.

[0060] In this application, the model for measuring the cooling capacity of an on-board refrigeration unit using the air enthalpy method involves only four types of energy flows: compressor power consumption P. Y Evaporator fan power P o Condenser fan power P i The heat transferred from the evaporator to the condenser (excluding fan power) T.

[0061] exist Figure 2 In the diagram, 4 represents the outdoor side of the air enthalpy method device, 5 represents the indoor side of the air enthalpy method device, A represents the low-temperature zone during measurement (for illustration only; the same applies to the high-temperature zone), B represents the high-temperature zone during actual measurement, 20 represents the vehicle-mounted refrigeration unit, and C represents the evaporator fan of the vehicle-mounted refrigeration unit. In this application, the power P of the evaporator fan will be measured. o D represents the condenser fan of the vehicle-mounted refrigeration unit, and its power P, i.e., the condenser fan power, will be measured in this application. i T represents the heat transferred from the evaporator to the condenser (excluding fan power), and F represents the compressor, which will be measured in this application as the compressor's power consumption P. Y .

[0062] It should be noted that in this application, the power consumption of the vehicle-mounted refrigeration unit is divided into three parts, namely, the power consumption P of the compressor. Y Evaporator fan power P o and condenser fan power P i The heat transferred from the evaporator to the condenser (excluding fan power) is T. At this point, the cooling capacity provided by the outdoor evaporator to the outdoor space can be expressed as:

[0063] Q tho =TP o (1)

[0064] In the formula:

[0065] Q tho —Cooling capacity of the vehicle-mounted refrigeration unit on the evaporator side, in watts (W);

[0066] T – Heat exchange capacity of the evaporator in the vehicle-mounted refrigeration unit, measured in W;

[0067] P o —Power consumption of the evaporator convection fan in the vehicle-mounted refrigeration unit, in watts (W).

[0068] The heating capacity provided by the indoor condenser to the building's central heating system can be expressed as:

[0069] Q thi =T+P i +P Y (2)

[0070] In the formula:

[0071] Q thi —Heating capacity of the vehicle-mounted refrigeration unit on the condenser side, in W;

[0072] P i —Power consumption of the evaporator convection fan in the vehicle-mounted refrigeration unit, in watts (W);

[0073] P Y —Power consumption of the onboard refrigeration unit compressor, in watts (W).

[0074] Subtracting equation (1) from equation (2) and rearranging, we get:

[0075] Q tho =Q thi -P i -P o -P Y =Q thi -P unit (3)

[0076] In the formula:

[0077] P unit —Power consumption of the vehicle-mounted refrigeration unit, in watts (W).

[0078] As can be seen from the above derivation, although the evaporator and condenser of the vehicle-mounted refrigeration unit are equipped with convection heat exchange fans, the cooling capacity of the vehicle-mounted refrigeration unit is still equal to the heating capacity on the condenser side minus the power consumption of the unit.

[0079] Therefore, in this application, the cooling capacity of the vehicle-mounted refrigeration unit is calculated based on the condenser heating capacity and the unit power consumption. Specifically, the difference between the condenser heating capacity and the unit power consumption is taken as the cooling capacity of the vehicle-mounted refrigeration unit, wherein the unit power consumption is the sum of the compressor power consumption, the evaporator fan power and the condenser fan power.

[0080] Furthermore, in some embodiments of this application, the evaporator-side component of the vehicle-mounted refrigeration unit is placed on the outdoor side of a pre-defined air enthalpy method device, and the condenser-side component of the vehicle-mounted refrigeration unit is placed on the indoor side of the air enthalpy method device. Specifically, for an integrated vehicle-mounted refrigeration unit, the vehicle-mounted refrigeration unit is placed on the intermediate partition wall of the air enthalpy method device, so that the evaporator-side component of the vehicle-mounted refrigeration unit is located on the outdoor side of the air enthalpy method device, and the condenser-side component is located on the indoor side of the air enthalpy method device. And for a split-type vehicle-mounted refrigeration unit, the evaporator of the vehicle-mounted refrigeration unit is placed on the outdoor side of the air enthalpy method device, and the condenser is placed on the indoor side of the air enthalpy method device.

[0081] In practical applications, for integrated vehicle-mounted refrigeration units, the evaporator side of the vehicle-mounted refrigeration unit can be located inside the air enthalpy method device via a window installed in the middle of the device, while the condenser is located outside the device and connected to the power cord. For split-type vehicle-mounted refrigeration units, the evaporator can be placed directly outside the air enthalpy method device, and the condenser can be placed directly inside the device and connected to refrigerant piping and power lines. After evacuating the vehicle-mounted refrigeration unit, refrigerant is injected according to the nominal value.

[0082] Furthermore, in some embodiments of this application, the method further includes: setting a pressure tapping interface at the center of each wall of the tooling in the condenser outlet duct; connecting the pressure tapping interface to the external static pressure connecting pipe of the air enthalpy method device, and connecting it to the pressure gauge of the air enthalpy method device for measuring external static pressure through a preset short pipe; wherein, the distance between the pressure tapping interface and the air outlet of the condenser is twice the cross-sectional dimension of the outlet; the pressure tapping interface is sealed by a pressure quick connector; the preset short pipe includes a PVC transparent flexible tube.

[0083] In practical applications, pressure taps are set at the center of each wall of the duct fixture. The distance between the pressure tap and the condenser outlet can be set to twice the average cross-sectional size of the outlet. The pressure taps are connected to the external static pressure connecting pipe of the air enthalpy method device, and connected to the external static pressure gauge of the air enthalpy method device with a preset short pipe. Paper tape and thermal insulation tape can also be used to seal and insulate the various interfaces of the duct fixture.

[0084] In addition, the pressure tapping interface (specifically, there can be 4) is connected to the static pressure connecting pipe outside the box, and the connecting pipe is used to connect to the pressure gauge of the static pressure outside the measuring machine. The pressure tapping interface is sealed at the position of the heat insulation plate by using a pressure quick connector. The connecting pipe can be a PVC transparent flexible tube. The pressure gauge is specifically set so that the positive end is connected to the pressure tapping interface and the negative end is open to the surrounding atmosphere.

[0085] Furthermore, in some embodiments of this application, the duct fixture for the condenser outlet duct includes a heat insulation plate; one end of the condenser outlet duct completely covers the condenser outlet, and the other end is connected to the air duct of the air enthalpy method device, and the cross-sectional dimension of the condenser outlet duct is larger than the dimension of the condenser outlet.

[0086] Specifically, the condenser air outlet is completely covered by a duct and connected to the air enthalpy method device's wind tunnel. The duct fixture, made of heat-insulating board, completely covers one end of the condenser air outlet and connects the other end to the air enthalpy method device's wind tunnel. The cross-sectional dimension of the duct is larger than the size of the condenser air outlet to ensure that the airflow from the outlet is not affected. Also, any possible air leakage points near the condenser air outlet are sealed.

[0087] Furthermore, in some embodiments of this application, the outdoor side is set to a high temperature and the indoor side to a low temperature, and the condenser heating capacity and unit power data are measured. Specifically, this includes: setting the indoor dry-bulb temperature of the air enthalpy method device to a high temperature and the outdoor dry-bulb temperature to a low temperature; not controlling the indoor and outdoor wet-bulb temperatures of the air enthalpy method device; turning off the humidifiers on the indoor and outdoor sides of the air enthalpy method device, installing wet-bulb gauze at the indoor air outlet, and opening the nozzle of the enthalpy difference airflow measuring device of the air enthalpy method device; and turning on the circulating fan, sampling fan, heater, and chiller on the indoor and outdoor sides of the air enthalpy method device.

[0088] In practical applications, the operating conditions during the testing of the vehicle-mounted refrigeration unit are set to high temperature on the indoor side and low temperature on the outdoor side, maintaining a certain temperature difference between the indoor and outdoor sides, and without controlling the ambient humidity. Specific operating steps may include: first, setting the air enthalpy method device to a high dry-bulb temperature on the indoor side and a low dry-bulb temperature on the outdoor side, maintaining a certain temperature difference between the indoor and outdoor sides, and not controlling the wet-bulb temperature on the indoor and outdoor sides; then, turning off the humidifiers on the indoor and outdoor sides of the air enthalpy method device, installing wet-bulb gauze at the indoor air outlet, opening the nozzle of the enthalpy difference airflow measuring device, and turning on the indoor and outdoor circulating fans, sampling fans, heaters, and refrigeration units of the air enthalpy method device.

[0089] The installation of wet-bulb gauze at the indoor air outlet involves heat exchange between the wet-bulb gauze and the indoor air outlet wet-bulb of the air enthalpy method device, and replacing the wet-bulb gauze based on a preset replacement interval. In practical applications, gauze compatible with the indoor air outlet wet-bulb platinum resistance thermometer of the air enthalpy method device can be used to ensure sufficient heat exchange with the platinum resistance thermometer, and the wet-bulb gauze should be replaced every 12 hours. Furthermore, when opening the nozzles of the enthalpy difference airflow measuring device of the air enthalpy method device, the number and diameter of the nozzles opened can be determined based on the condenser airflow of the vehicle-mounted refrigeration unit.

[0090] In addition, in this application, the specific operations for sealing any possible air leaks in the outdoor room of the air enthalpy method device may include: sealing the window of the intermediate partition wall of the air enthalpy method device with insulation board, paper tape, and insulation tape; sealing the intermediate pipes and wiring connection holes of the air enthalpy method device with insulation material and paper tape; and closing the door of the outdoor room of the air enthalpy method device and checking for air leaks, and sealing any leaks with paper tape.

[0091] In practical applications, the above-mentioned test can be performed using the test software of the air enthalpy method device. For example, after the above preparations are completed, the test software of the air enthalpy method device is turned on, the test conditions are set, the nozzle is selected, and the test software measures and records the heating capacity, air volume, and unit power data of the vehicle-mounted unit. When the indoor dry-bulb temperature and the outdoor dry-bulb temperature reach the set temperature, the temperature fluctuation is no greater than ±0.1℃, and the system has been running for more than 30 minutes, the data is taken at least once every 30 seconds. The data is continuously measured, and the average value of the data over a period of time is taken as the measured value.

[0092] Furthermore, in this application, to further ensure the accuracy of system parameter measurements, the various components and calculation principles in the air enthalpy method device can be calibrated or corrected to guarantee the accuracy of the basic measurement parameters. Specifically, this includes:

[0093] 1. Calibrate and correct the temperature measurement system. Specifically, the temperature measurement system of the air enthalpy method device generally includes an industrial platinum resistance thermometer and a sampling fan (used to measure the sampling fan speed). In this application, a second-class standard platinum resistance thermometer and a constant temperature water bath are used to calibrate the industrial platinum resistance thermometer, and an anemometer is used to measure the sampling fan speed to ensure the accuracy of all industrial platinum resistance thermometers and the wind speed measurement in the air enthalpy method device.

[0094] 2. Calibrate and correct the pressure measurement system. Specifically, the pressure measurement system of the air enthalpy method device generally includes pressure sensors for measuring wind static pressure, pressure difference before and after the nozzle, and atmospheric pressure. In this application, pressure sources and pressure gauges are used to calibrate the pressure sensors to ensure the measurement accuracy of all pressure sensors in the air enthalpy method device.

[0095] 3. Calibrate and correct the power measurement system. The power measurement system of the air enthalpy method device generally includes a current transformer and a power meter. In this application, a power source is used to calibrate the power meter phase by phase to ensure the accuracy of the power consumption measurement of all electrical equipment in the enthalpy difference test device.

[0096] 4. Correction is made to the heating capacity of the air enthalpy method device. Specifically, in this application, a correction model for the deviation is established. Combining basic concepts of heat transfer, the absolute value of the deviation is considered as the heat leakage of the enthalpy difference chamber wind tunnel and the deviation of the fixed system, and then fitted using least squares. In practical applications, a sample with a heating capacity value that has already been measured in a calorimeter can be used as a transfer sample. This sample can be installed in the air enthalpy method device, and the air enthalpy method device can be used to repeatedly test the heating capacity transfer sample. The heating capacity measurement range can include 4000W, 6000W, 7000W, 8000W, and 10000W to repeatedly cover the heating capacity range of the condenser side of the vehicle-mounted refrigeration unit. At the same time, each heating capacity measurement range is repeated 5 times or more to enable the analysis of measurement repeatability.

[0097] Figure 3 This is a schematic diagram illustrating the actual testing principle of the vehicle-mounted refrigeration unit cooling capacity testing method provided in this embodiment of the invention. Figure 3 The document shows the specific hardware and the layout of related test points. Figure 3 In the diagram, 1 is the air supply outlet, 2 is the air handling unit related to the test, 3 is the return air outlet, 4 is the outdoor side of the air enthalpy method device, 5 is the indoor side of the air enthalpy method device, 6 is the dry-bulb sampler of the air enthalpy method device, 7 is the outdoor sampling fan of the air enthalpy method device (the outdoor side air intake sampling rake includes the aforementioned dry-bulb sampler 6 and outdoor sampling fan 7), 8 is the dry-wet-bulb sampler of the air enthalpy method device, and 9 is the indoor sampling fan of the air enthalpy method device (the indoor side air intake sampling rake includes the aforementioned dry-wet-bulb sampler 8 and indoor sampling fan 9). 10 is the outdoor return air dry-bulb temperature measurement point of the air enthalpy method device (i.e., the setting location for the outdoor return air dry-bulb temperature of the air enthalpy method device, the same applies below), 11 is the indoor return air dry-bulb temperature measurement point of the air enthalpy method device, 12 is the indoor return air wet-bulb temperature measurement point of the air enthalpy method device, 13 is the enthalpy difference airflow measurement device of the air enthalpy method device, 14 is the enthalpy difference wind tunnel of the air enthalpy method device, and 15 is the air enthalpy value. 16 is the measurement point for the temperature before the nozzle of the air enthalpy method device; 17 is the measurement point for the dry-bulb temperature of the indoor air outlet of the air enthalpy method device; 18 is the measurement point for the pressure difference before and after the nozzle of the air enthalpy method device; 19 is the power measurement device of the air enthalpy method device; 20 is the vehicle-mounted refrigeration unit to be tested; 21 is the evaporator of the vehicle-mounted refrigeration unit; and 22 is the condenser of the vehicle-mounted refrigeration unit.

[0098] To verify the testing method for the cooling capacity of the vehicle-mounted refrigeration unit provided in this application, this application provides a specific experimental verification process, as follows:

[0099] The test used an integrated vehicle-mounted refrigeration unit. The evaporator side component of the vehicle-mounted refrigeration unit was placed on the outdoor side of the air enthalpy method device. The outdoor side air intake sampling rake was arranged 15cm outside the air inlet of the evaporator of the vehicle-mounted unit. The air outlet of the evaporator was allowed to ventilate freely, ensuring that there were no objects obstructing it within two meters.

[0100] The condenser-side component of the vehicle-mounted refrigeration unit is placed on the indoor side of the air enthalpy method device. The indoor side air intake sampling rake is arranged 15cm outside the air inlet of the vehicle-mounted unit condenser. A duct is made for the condenser outlet, and the cross-sectional size of the duct is larger than the size of the condenser outlet to ensure that the air outlet is not affected. Any possible air leakage near the condenser outlet is sealed. The condenser outlet is completely covered by the duct and connected to the air tunnel of the air enthalpy method device. The duct, condenser, and air tunnel are sealed and insulated.

[0101] Install a baffle 1 meter away from the air outlet of the enthalpy difference air volume measuring device to prevent the air outlet of the enthalpy difference air volume measuring device from blowing directly around the condenser of the vehicle-mounted refrigeration unit.

[0102] Seal any possible air leaks in the outdoor room of the air enthalpy method device to minimize water vapor penetration into the outdoor room.

[0103] During the testing of the vehicle-mounted refrigeration unit, the operating conditions were set as follows: indoor dry-bulb temperature 30℃ and outdoor dry-bulb temperature 0℃.

[0104] In this application, a single overall test requires three independent, repeated measurements. After each measurement, the unit's defrosting function is activated. After defrosting, the unit re-enters operating mode. The recorded heating capacity and input power (i.e., the unit power mentioned in this application, specifically the sum of compressor power consumption, evaporator fan power, and condenser fan power) curves during the test are shown below. Figures 4 to 6 As shown;

[0105] In addition, during the above independent repeated measurement process, the heating capacity, air volume and unit power data of the vehicle-mounted unit condenser are measured simultaneously (where air volume can be used to calculate the corresponding fan power). After the data stabilizes, 35 minutes of steady-state data are selected as the data for subsequent calculations.

[0106] The cooling capacity of the vehicle-mounted refrigeration unit is equal to the heating capacity of the condenser side minus the power consumption of the unit. The cooling capacity of the vehicle-mounted refrigeration unit is obtained from the heating capacity of the condenser and the power of the unit. The specific results are shown in Table 1.

[0107] Table 1. Measurement results of cooling capacity of vehicle-mounted refrigeration unit

[0108]

[0109] As shown in the table, the cooling capacity measurements for the three tests were 5225.6W, 5221.8W, and 5218.5W, with an average of 5222.0W. The standard deviation, calculated using the range method (range 7.1W, conversion factor 1.69), was 4.2W. A third-party comparison unit, a transportation refrigeration equipment company, measured the unit's cooling capacity using a dedicated calorimeter, obtaining a result of 5216W. Therefore, the air enthalpy method for measuring vehicle-mounted refrigeration units established in this paper, along with the corresponding measurement method, can accurately measure the unit's cooling capacity, with a deviation of only 6.0W from the reference value provided by the third-party unit, representing a relative deviation of 0.12%.

[0110] In addition, by Figures 4 to 6 It can be seen that the air enthalpy method takes only about 2 hours to measure the vehicle-mounted refrigeration unit each time, which reduces the balance time of heat leakage in the box and greatly improves the measurement efficiency compared with the calorimeter method.

[0111] It should be noted that in the description of this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means at least two.

[0112] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0113] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0114] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0115] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0116] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0117] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0118] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for testing the cooling capacity of a vehicle-mounted refrigeration unit, characterized in that, include: The evaporator-side component of the vehicle-mounted refrigeration unit is placed on the outdoor side of the preset air enthalpy method device, and the air intake sampling rake on the outdoor side of the air enthalpy method device is set outside the air inlet of the evaporator; wherein, the evaporator-side component includes the evaporator; A condenser outlet air duct is installed at the air outlet of the condenser of the vehicle-mounted refrigeration unit. The condenser side component of the vehicle-mounted refrigeration unit is placed on the indoor side of the air enthalpy method device, and the air intake sampling rake of the indoor side of the air enthalpy method device is set outside the air inlet of the condenser, and the air outlet duct of the condenser is connected to the air tunnel of the air enthalpy method device. The outdoor side was set to a low temperature and the indoor side to a high temperature, and the condenser heating capacity and unit power data were measured. Based on the principle of energy conservation, the cooling capacity of the vehicle-mounted refrigeration unit is calculated using condenser heating capacity and unit power data. The unit power data includes compressor power consumption, evaporator fan power, and condenser fan power.

2. The method according to claim 1, characterized in that, The evaporator-side assembly of the vehicle-mounted refrigeration unit is located on the outdoor side of the preset air enthalpy method device, and the condenser-side assembly of the vehicle-mounted refrigeration unit is located on the indoor side of the air enthalpy method device, including: For integrated vehicle-mounted refrigeration units, the vehicle-mounted refrigeration unit is installed on the middle partition wall of the air enthalpy method device, so that the evaporator side component of the vehicle-mounted refrigeration unit is located on the outdoor side of the air enthalpy method device, and the condenser side component is located on the indoor side of the air enthalpy method device. For split-type vehicle-mounted refrigeration units, the evaporator of the vehicle-mounted refrigeration unit is placed on the outdoor side of the air enthalpy method device, and the condenser is placed on the indoor side of the air enthalpy method device.

3. The method according to claim 2, characterized in that, Also includes: A pressure tapping interface is provided at the center of each wall of the duct tooling at the air outlet of the condenser. Connect the pressure tapping port to the external static pressure connecting pipe of the air enthalpy method device, and connect the pressure gauge to the external static pressure measuring machine of the air enthalpy method device through a preset short pipe; The pressure tapping interface is located at a distance from the air outlet of the condenser that is twice the cross-sectional dimension of the air outlet; the pressure tapping interface is sealed by a pressure quick connector; and the pre-set short pipe includes a PVC transparent flexible tube.

4. The method according to claim 3, characterized in that, The duct fixture for the condenser outlet duct includes a heat insulation plate; One end of the condenser outlet duct completely covers the condenser outlet, and the other end is connected to the air duct of the air enthalpy method device. The cross-sectional dimension of the condenser outlet duct is larger than the size of the condenser outlet.

5. The method according to claim 4, characterized in that, The setting of the outdoor side as low temperature and the indoor side as high temperature, and the measurement of condenser heating capacity and unit power data, including: The indoor dry-bulb temperature of the air enthalpy method device is set to high temperature, and the outdoor dry-bulb temperature is set to low temperature. The indoor and outdoor wet-bulb temperatures of the air enthalpy method device are not controlled. Turn off the humidifiers on both the indoor and outdoor sides of the air enthalpy method device, install the wet bulb gauze at the air outlet on the indoor side, and turn on the nozzle of the enthalpy difference airflow measuring device of the air enthalpy method device. Turn on the indoor and outdoor circulating fans, sampling fans, heaters, and refrigerators of the air enthalpy method device.

6. The method according to claim 5, characterized in that, The indoor-side air outlet wet bulb gauze includes: The wet cloth gauze at the air outlet is brought into contact with the wet bulb of the indoor air outlet of the air enthalpy method device for heat exchange, and the wet bulb gauze is replaced based on a preset replacement time.

7. The method according to claim 6, characterized in that, The nozzle of the enthalpy difference airflow measuring device of the open air enthalpy method device includes: The number and diameter of nozzles to be opened are determined based on the airflow of the condenser of the vehicle-mounted refrigeration unit; and the nozzles of the enthalpy difference airflow measuring device are opened based on the number and diameter of nozzles to be opened.

8. The method according to claim 5, characterized in that, The method of setting the outdoor side to a low temperature and the indoor side to a high temperature, and measuring the condenser heating capacity and unit power data, also includes: After the outdoor side stabilizes at a preset low temperature and the indoor side stabilizes at a preset high temperature for a preset duration, multiple sets of condenser heating capacity and unit power data are collected using the preset air enthalpy method test software.

9. The method according to claim 8, characterized in that, The cooling capacity of the vehicle-mounted refrigeration unit is calculated using condenser heating capacity and unit power data, including: The difference between the condenser's heating capacity and the unit's power consumption is taken as the cooling capacity of the vehicle-mounted refrigeration unit, wherein the unit's power consumption is the sum of the compressor's power consumption, the evaporator fan's power consumption, and the condenser fan's power consumption.

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