Method for measuring heat exchange efficiency of heat exchanger and vehicle

Abstract

The invention provides a method for measuring the heat exchange efficiency of a heat exchanger and a vehicle, and the method comprises the steps: obtaining a temperature difference value between a first medium at a hot side channel inlet and a second medium at a cold side channel inlet; the heat exchange amount of the first medium flowing through the hot side channel is obtained; and obtaining a first heat capacity rate of the first medium at the hot side channel inlet, obtaining a second heat capacity rate of the second medium at the cold side channel inlet, and obtaining the heat exchange efficiency of the heat exchanger through a formula according to the temperature difference value, the heat exchange amount, the first heat capacity rate and the second heat capacity rate. The thermodynamic parameters of the first medium of the heat exchanger in the hot side channel and the thermodynamic parameters of the second medium of the heat exchanger in the cold side channel are directly obtained, calculation can be achieved by additionally installing a corresponding measuring sensor in the heat exchanger in the vehicle, and the obtaining mode of the heat exchange efficiency of the heat exchanger is greatly simplified; and the data result of the heat exchange efficiency is closer to the actual operation of the whole vehicle, and the data error is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal management of new energy vehicles, and in particular to a method for measuring the efficiency of a heat exchanger and a vehicle. Background Art

[0002] Thermal management is an important part of the whole vehicle control of new energy electric vehicles. Furthermore, the energy consumption of the air-conditioning thermal management system accounts for about 25% of the whole vehicle energy consumption. Therefore, the accuracy of the calculation of the air-conditioning thermal management energy consumption is crucial. In addition, the acquisition and accuracy of the heat exchange efficiency map (map) of the heat exchange module during the simulation of air-conditioning thermal management directly affects the accuracy of the air-conditioning thermal management energy consumption.

[0003] The only way to obtain data for traditional heat exchange efficiency charts is to use an enthalpy difference test room. The enthalpy difference test requires a large component bench to be built in a specific venue for testing. The enthalpy difference test has the problems of high investment cost, long test cycle, manual screening of data processing, and large workload, so it is difficult to obtain relevant test data. Even if the test data can be obtained, since the enthalpy difference test is conducted on a component bench, its boundary conditions and control strategies are different from those in the actual operation of the vehicle, resulting in deviations in the test data. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the difficulty in obtaining the heat exchange efficiency of the vehicle heat exchanger in the prior art and the existence of data deviation, thereby providing a method for measuring the heat exchange efficiency of the heat exchanger and a vehicle.

[0005] In order to solve the above problems, the present invention provides a method for measuring the heat exchange efficiency of a heat exchanger. The heat exchanger includes a hot side channel and a cold side channel. The first medium flows through the hot side channel and the second medium flows through the cold side channel. The measuring method includes: obtaining the temperature difference between the first medium at the hot side channel inlet and the second medium at the cold side channel inlet; obtaining the heat exchange amount after the first medium flows through the hot side channel; obtaining the first heat capacity ratio of the first medium at the hot side channel inlet, and obtaining the second heat capacity ratio of the second medium at the cold side channel inlet. According to the temperature difference, the heat exchange amount, the first heat capacity ratio and the second heat capacity ratio, the heat exchange efficiency of the heat exchanger is obtained by the following formula: Among them, ∈ is the heat exchange efficiency of the heat exchanger, φ is the heat exchange amount after the first medium flows through the hot side channel, C min is the minimum value of the first heat capacity rate and the second heat capacity rate, T hotin -T coldin It is the temperature difference between the first medium at the hot side channel inlet and the second medium at the cold side channel inlet.

[0006] Optionally, the heat exchange amount after the first medium flows through the hot side channel is obtained by the following formula: φ = m hot ×(hhotin -h hotout ), where φ is the heat exchange capacity of the first medium after it flows through the hot side channel, m hot is the mass flow rate of the first medium, h hotin is the specific enthalpy of the first medium at the entrance of the hot side channel, h hotout is the specific enthalpy of the first medium at the outlet of the hot side channel.

[0007] Optionally, the measurement method also includes: obtaining a first temperature of the first medium at the inlet of the hot side channel; obtaining a first pressure of the first medium at the inlet of the hot side channel; obtaining a second temperature of the first medium at the outlet of the hot side channel; obtaining a second pressure of the first medium at the outlet of the hot side channel; obtaining a specific enthalpy of the first medium at the inlet of the hot side channel based on the physical properties, first temperature and first pressure of the first medium; obtaining a specific enthalpy of the first medium at the outlet of the hot side channel based on the physical properties, second temperature and second pressure of the first medium.

[0008] Optionally, the first heat capacity ratio is obtained by the following formula: C hot =c hotin ×m hot Among them, C hot is the first heat capacity, c hotin is the specific heat capacity of the first medium at the entrance of the hot side channel, m hot is the mass flow rate of the first medium.

[0009] Optionally, the second heat capacity ratio is obtained by the following formula: C cold =c coldin ×m cold Among them, C cold is the second heat capacity, c coldin is the specific heat capacity of the second medium at the entrance of the cold side channel, m cold is the mass flow rate of the second medium.

[0010] Optionally, the measurement method also includes: obtaining a first temperature of the first medium at the entrance of the hot side channel; obtaining a first pressure of the first medium at the entrance of the hot side channel; and obtaining the specific heat capacity of the first medium at the entrance of the hot side channel based on the physical properties, first temperature and first pressure of the first medium.

[0011] Optionally, the measurement method also includes: obtaining a third temperature of the second medium at the entrance of the cold side channel; obtaining a third pressure of the second medium at the entrance of the cold side channel; and obtaining the specific heat capacity of the second medium at the entrance of the cold side channel based on the physical properties, third temperature and third pressure of the second medium.

[0012] Optionally, the mass flow rate of the first medium is obtained by the following formula: m hot =ρ hotin ×Qhotin ; Among them, m hot is the mass flow rate of the first medium, ρ hotin is the density of the first medium at the entrance of the hot side channel, Q hotin is the volume flow rate of the first medium at the inlet of the hot side channel.

[0013] Optionally, the measurement method also includes: obtaining a first temperature of the first medium at the entrance of the hot side channel; obtaining a first pressure of the first medium at the entrance of the hot side channel; and obtaining a density of the first medium at the entrance of the hot side channel based on the physical properties, first temperature and first pressure of the first medium.

[0014] Optionally, the mass flow rate of the second medium is obtained by the following formula: m cold =ρ coldin ×Q coldin ; Among them, m cold is the mass flow rate of the second medium, ρ coldin is the density of the second medium at the entrance of the cold side channel, Q coldin is the volume flow rate of the second medium at the inlet of the cold side channel.

[0015] Optionally, the measurement method also includes: obtaining a third temperature of the second medium at the entrance of the cold side channel; obtaining a third pressure of the second medium at the entrance of the cold side channel; and obtaining a density of the second medium at the entrance of the cold side channel based on the physical properties, third temperature and third pressure of the second medium.

[0016] The present invention also provides a computer-readable storage medium on which a heat exchanger thermal efficiency calculation program is stored. When the heat exchanger thermal efficiency calculation program is executed by a processor, the above-mentioned heat exchange efficiency measurement method of the heat exchanger is implemented.

[0017] The present invention also provides a heat exchange efficiency measurement system for a heat exchanger, comprising: a heat exchanger, comprising a hot side channel and a cold side channel, a first medium flowing through the hot side channel, and a second medium flowing through the cold side channel; a first measuring component, arranged at the inlet of the hot side channel of the heat exchanger, the first measuring component being used to measure a first temperature, a first pressure and a flow rate of the first medium at the inlet of the hot side channel; a second measuring component, arranged at the outlet of the hot side channel of the heat exchanger, the second measuring component being used to measure a second temperature and a second pressure of the first medium at the outlet of the hot side channel; a third measuring component, arranged at the inlet of the cold side channel of the heat exchanger, the third measuring component being used to measure a third temperature, a third pressure and a flow rate of the second medium at the inlet of the cold side channel; a computing module, communicatively connected to the first measuring component, the second measuring component and the third measuring component, the computing module being used to execute the above-mentioned measurement method.

[0018] Optionally, it also includes a storage device, which is communicatively connected to the calculation module, and stores a first physical property chart of the first medium. The calculation module can retrieve the specific enthalpy of the first medium at the inlet of the hot side channel in the first physical property chart according to the first temperature and the first pressure; and / or the calculation module can retrieve the specific enthalpy of the first medium at the outlet of the hot side channel in the first physical property chart according to the second temperature and the second pressure.

[0019] Optionally, it also includes a storage device, which is communicatively connected to the calculation module, and the storage device stores a first physical property chart of the first medium and a second physical property chart of the second medium. The calculation module can retrieve the specific heat capacity of the first medium at the entrance of the hot side channel in the first physical property chart according to the first temperature and the first pressure; and / or the calculation module can retrieve the specific heat capacity of the second medium at the entrance of the cold side channel in the second physical property chart according to the third temperature and the third pressure.

[0020] Optionally, a storage device is further included, which is communicatively connected to the computing module, and the storage device stores a first physical property chart of the first medium and a second physical property chart of the second medium. The computing module can retrieve the density of the first medium at the entrance of the hot side channel in the first physical property chart according to the first temperature and the first pressure; and / or the computing module can retrieve the density of the second medium at the entrance of the cold side channel in the second physical property chart according to the third temperature and the third pressure.

[0021] Optionally, the heat exchanger is an air-cooled heat exchanger, the first measuring component includes a first temperature sensor, a first pressure sensor and a first flow sensor, the second measuring component includes a second temperature sensor and a second pressure sensor, and the third measuring component includes a third temperature sensor, a third pressure sensor and a wind speed sensor.

[0022] Optionally, the heat exchanger is a liquid-cooled heat exchanger, the first measuring component includes a first temperature sensor, a first pressure sensor and a first flow sensor, the second measuring component includes a second temperature sensor and a second pressure sensor, and the third measuring component includes a third temperature sensor, a third pressure sensor and a second flow sensor.

[0023] The present invention also provides a vehicle, comprising the above-mentioned heat exchange efficiency measurement system of the heat exchanger.

[0024] The present invention has the following advantages:

[0025] By utilizing the technical solution of the present invention, the thermodynamic parameters of the first medium in the hot side channel of the heat exchanger and the thermodynamic parameters of the second medium in the cold side channel of the heat exchanger are directly obtained, including temperature difference, heat transfer capacity, and heat capacity ratio, and the heat exchange efficiency of the heat exchanger is directly calculated. The above-mentioned measurement method can realize the calculation by adding corresponding measurement sensors to the heat exchanger in the vehicle, which greatly simplifies the method of obtaining the heat exchange efficiency of the heat exchanger, and directly obtains the thermodynamic parameters of the first medium and the second medium during the operation of the heat exchanger. Therefore, the data results of the heat exchange efficiency are closer to the actual operation of the whole vehicle, reducing data errors. Therefore, the technical solution of the present invention solves the defects of the difficulty in obtaining the heat exchange efficiency of the vehicle heat exchanger and the deviation of the data in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A schematic flow chart showing a method for measuring the heat exchange efficiency of a heat exchanger of the present invention is shown;

[0028] Figure 2 Shows Figure 1 A further flow diagram of step S2 in FIG.

[0029] Figure 3 Shows Figure 1 A further flow chart of step S3 in

[0030] Figure 4 The figure shows the installation schematic diagram of the first embodiment of the medium state measurement system of the present invention;

[0031] Figure 5 The figure shows the installation diagram of the second embodiment of the medium state measurement system of the present invention.

[0032] Description of reference numerals:

[0033] 10. Heat exchanger; 20. Hot side channel; 21. Hot side channel inlet; 22. Hot side channel outlet; 30. Cold side channel; 31. Cold side channel inlet; 100. First measuring component; 101. First temperature sensor; 102. First pressure sensor; 103. First flow sensor; 200. Second measuring component; 201. Second temperature sensor; 202. Second pressure sensor; 300. Third measuring component; 301. Third temperature sensor; 302. Third pressure sensor; 303. Wind speed sensor; 304. Second flow sensor. DETAILED DESCRIPTION

[0034] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0036] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] like Figure 1 , Figure 4 and Figure 5 As shown, the present application provides a method for measuring the heat exchange efficiency of a heat exchanger, wherein the heat exchanger 10 includes a hot side channel 20 and a cold side channel 30, a first medium flows through the hot side channel, and a second medium flows through the cold side channel.

[0039] Furthermore, an embodiment of the method for measuring the heat exchange efficiency of a heat exchanger according to the present application includes:

[0040] Step S1: obtaining the temperature difference between the first medium at the hot side channel inlet 21 and the second medium at the cold side channel inlet 31;

[0041] Step S2: obtaining the heat exchange amount of the first medium after flowing through the hot side channel 20;

[0042] Step S3: obtaining a first heat capacity of the first medium at the hot side channel inlet 21, and obtaining a second heat capacity of the second medium at the cold side channel inlet 31,

[0043] Step S4 obtains the heat exchange efficiency of the heat exchanger by the following formula according to the temperature difference, the heat exchange amount, the first heat capacity ratio and the second heat capacity ratio:

[0044]

[0045] Where, ∈ is the heat exchange efficiency of the heat exchanger, φ is the heat exchange amount after the first medium flows through the hot side channel 20, C min is the minimum value of the first heat capacity rate and the second heat capacity rate, T hotin -T coldin It is the temperature difference between the first medium at the hot side channel inlet 21 and the second medium at the cold side channel inlet 31 .

[0046] By using the technical solution of this embodiment, the thermodynamic parameters of the first medium in the hot side channel 20 of the heat exchanger 10 and the thermodynamic parameters of the second medium in the cold side channel 30 of the heat exchanger 10 are directly obtained, including the temperature difference, heat transfer amount, and heat capacity ratio, and the heat exchange efficiency of the heat exchanger is directly calculated. The above-mentioned measurement method can realize the calculation by adding corresponding measurement sensors to the heat exchanger in the vehicle, which greatly simplifies the method of obtaining the heat exchange efficiency of the heat exchanger, and directly obtains the thermodynamic parameters of the first medium and the second medium during the operation of the heat exchanger. Therefore, the data results of the heat exchange efficiency are closer to the actual operation of the whole vehicle, reducing data errors. Therefore, the technical solution of this embodiment solves the defects of the difficulty in obtaining the heat exchange efficiency of the vehicle heat exchanger and the deviation of the data in the prior art.

[0047] like Figure 4 and Figure 5 As shown, in this embodiment, the heat exchanger 10 is used to exchange heat between a first medium and a second medium. The first medium flows in a hot side channel 20, and the second medium flows in a cold side channel 30. The temperature of the first medium is higher than that of the second medium. Therefore, in the heat exchanger 10, the heat of the first medium is transferred to the second medium, thereby performing heat exchange.

[0048] Furthermore, the first medium is liquid, and thus the hot side channel 20 is a pipeline structure.

[0049] like Figure 4 As shown, the heat exchanger 10 may be an air-cooled heat exchanger, in which case the second medium is gas, and the cold side channel 30 is an air duct, which may be formed in the form of a pipe, fin gaps, or the like.

[0050] like Figure 5 As shown, the heat exchanger 10 may also be a liquid-cooled heat exchanger, in which case the second medium is a liquid and the cold side channel 30 is a pipeline structure.

[0051] In step S1, the temperature value of the first medium at the hot side channel inlet 21 and the temperature value of the second medium at the cold side channel inlet 31 are first obtained, and then the two are subtracted to obtain the temperature difference between the first medium at the hot side channel inlet 21 and the second medium at the cold side channel inlet 31.

[0052] Optionally, the temperature value of the above-mentioned medium at the hot side channel inlet 21 and the temperature value of the second medium at the cold side channel inlet 31 can be achieved by installing temperature sensors at the hot side channel inlet 21 and the cold side channel inlet 31 of the heat exchanger 10.

[0053] In step S2, the heat exchange amount of the first medium after flowing through the hot side channel 20 is obtained, that is, the heat transferred to the outside after the first medium with a specific mass flows through the hot side channel 20.

[0054] In step S3, the first heat capacity of the first medium at the hot side channel inlet 21 is obtained, the second heat capacity of the second medium at the cold side channel inlet 31 is obtained, and the minimum value of the two is taken and substituted into the formula in step S4 for calculation.

[0055] It should be noted that the above step S4 can be applied to directly calculate the heat exchange efficiency of the heat exchanger 10 during actual driving of the vehicle, and provide real-time heat exchange efficiency data to the vehicle thermal management system as a basis for the vehicle thermal management strategy.

[0056] Furthermore, the above step S4 can also test the heat exchange efficiency of the heat exchanger 10 under different vehicle driving states and different changes in external ambient temperature, and obtain heat exchange efficiency data. According to the heat exchange efficiency data under a specific vehicle form state and a specific external ambient temperature, a heat exchange efficiency map of the heat exchanger 10 is output, and the map is stored in the vehicle's memory. The vehicle thermal management system can call the map to obtain the heat exchange efficiency data under a specific vehicle form state and a specific external ambient temperature.

[0057] For example, the following working conditions may be selected to test the heat exchange efficiency of the heat exchanger 10:

[0058] 1. Ambient temperature: from -20℃ to 40℃, interval 5℃;

[0059] 2. Vehicle speed: from 10km / h to 140km / h, in intervals of 10km / h;

[0060] 3. Power output torque: from 10Nm to peak power torque, interval 30Nm.

[0061] The condition for stopping the test under each working condition is that the hot side channel outlet 22 of the heat exchanger 10 basically reaches thermal equilibrium.

[0062] like Figure 2 As shown, in the above step S2, it further includes:

[0063] Step S21: The heat exchange amount of the first medium after flowing through the hot side channel 20 is obtained by the following formula:

[0064] φ=m hot ×(h hotin -h hotout );

[0065] Wherein, φ is the heat exchange amount after the first medium flows through the hot side channel 20, m hot is the mass flow rate of the first medium, h hotin is the specific enthalpy of the first medium at the hot side channel inlet 21, h hotout is the specific enthalpy of the first medium at the hot side channel outlet 22.

[0066] In step S21, by multiplying the mass flow rate of the first medium by the specific enthalpy of the first medium at the hot side channel inlet 21 minus the specific enthalpy of the first medium at the hot side channel outlet 22, the heat released to the outside by the first medium under a certain mass, that is, the heat exchange capacity, can be obtained.

[0067] Furthermore, the measuring method further comprises:

[0068] Obtaining a first temperature of the first medium at the hot side channel inlet 21;

[0069] Obtaining a first pressure of the first medium at the hot side channel inlet 21;

[0070] According to the physical properties, the first temperature and the first pressure of the first medium, the specific enthalpy of the first medium at the hot side channel inlet 21 is obtained.

[0071] Specifically, the specific enthalpy of a substance at a specific pressure and temperature is a fixed value. Therefore, according to the specific substance type (refrigerant type) of the first medium, and the first temperature value and the first pressure value at the hot side channel inlet 21, the specific value of the specific enthalpy of the first medium can be obtained by looking up the table. The table can be pre-stored in the memory of the vehicle.

[0072] Furthermore, a temperature sensor and a pressure sensor may be installed at the hot side channel inlet 21 to obtain the first temperature and the first pressure. According to the real-time values ​​of the first temperature and the first pressure, the specific enthalpy of the first medium at the hot side channel inlet 21 may be obtained by looking up the table.

[0073] Similarly, by obtaining the second temperature of the first medium at the hot side channel outlet 22 and obtaining the second pressure of the first medium at the hot side channel outlet 22, the specific enthalpy of the first medium at the hot side channel outlet 22 can be obtained by looking up the table.

[0074] Furthermore, a temperature sensor and a pressure sensor may be installed at the hot side channel outlet 22 to obtain the second temperature and the second pressure. According to the real-time values ​​of the second temperature and the second pressure, the specific enthalpy of the second medium at the hot side channel outlet 22 may be obtained by looking up the table.

[0075] like Figure 3 As shown, in the above step S3, it further includes:

[0076] Step S31: The first heat capacity ratio is obtained by the following formula:

[0077] C hot =c hotin ×m hot ;

[0078] Among them, C hot is the first heat capacity, c hotin is the specific heat capacity of the first medium at the hot side channel inlet 21, m hot is the mass flow rate of the first medium.

[0079] Step S32: The second heat capacity ratio is obtained by the following formula:

[0080] C cold =c coldin ×m cold ;

[0081] Among them, C cold is the second heat capacity, c coldin is the specific heat capacity of the second medium at the cold side channel inlet 31, m cold is the mass flow rate of the second medium.

[0082] The first heat capacity of the first medium and the second heat capacity of the second medium are obtained through step S31 and step S32, and when calculating in step S4, the smallest of the two specific values ​​is substituted into the formula for calculation.

[0083] Furthermore, step S31 also includes:

[0084] Obtaining a first temperature of the first medium at the hot side channel inlet 21;

[0085] Obtaining a first pressure of the first medium at the hot side channel inlet 21;

[0086] According to the physical properties of the first medium, the first temperature and the first pressure, the specific heat capacity of the first medium at the hot side channel inlet 21 is obtained.

[0087] Specifically, the specific heat capacity of a substance at a specific pressure and temperature is a fixed value. Therefore, according to the specific substance type (refrigerant type) of the first medium, and the first temperature value and the first pressure value at the hot side channel inlet 21, the specific value of the specific heat capacity of the first medium can be obtained by looking up the table. The table can be pre-stored in the memory of the vehicle.

[0088] Furthermore, a temperature sensor and a pressure sensor may be installed at the hot side channel inlet 21 to obtain the first temperature and the first pressure. According to the real-time values ​​of the first temperature and the first pressure, the specific heat capacity of the first medium at the hot side channel inlet 21 may be obtained by looking up the table.

[0089] Furthermore, step S32 also includes:

[0090] Obtaining a third temperature of the second medium at the cold side channel inlet 31;

[0091] Obtaining a third pressure of the second medium at the cold side channel inlet 31;

[0092] According to the physical properties of the second medium, the third temperature and the third pressure, the specific heat capacity of the second medium at the cold side channel inlet 31 is obtained.

[0093] Specifically, the specific heat capacity of a substance is a fixed value under a specific pressure and temperature. Therefore, according to the specific substance type (coolant or air cooling) of the second medium, and the third temperature value and the third pressure value at the cold side channel inlet 31, the specific value of the specific heat capacity of the second medium can be obtained by looking up the table. The table can be pre-stored in the memory of the vehicle.

[0094] Furthermore, a temperature sensor and a pressure sensor may be installed at the cold side channel inlet 31 to obtain the third temperature and the third pressure. According to the real-time values ​​of the third temperature and the third pressure, the specific heat capacity of the second medium at the cold side channel inlet 31 may be obtained by looking up the table.

[0095] Furthermore, in both the above-mentioned step S21 and step 31, it is necessary to obtain the mass flow value of the first medium, so the following describes how to obtain the mass flow value of the first medium.

[0096] Specifically, the mass flow rate of the first medium is obtained by the following formula:

[0097] m hot =ρ hotin ×Q hotin ;

[0098] Among them, m hot is the mass flow rate of the first medium, ρ hotin is the density of the first medium at the hot side channel inlet 21, Q hotin is the volume flow rate of the first medium at the hot side channel inlet 21.

[0099] The density of the first medium at the hot side channel inlet 21 is obtained by:

[0100] Obtaining a first temperature of the first medium at the hot side channel inlet 21;

[0101] Obtaining a first pressure of the first medium at the hot side channel inlet 21;

[0102] According to the physical properties of the first medium, the first temperature and the first pressure, the density of the first medium at the hot side channel inlet 21 is obtained.

[0103] Specifically, the density of a substance is a fixed value at a specific pressure and temperature. Therefore, according to the specific substance type (refrigerant type) of the first medium, and the first temperature value and the first pressure value at the hot side channel inlet 21, the specific value of the density of the first medium can be obtained by looking up the table. The table can be pre-stored in the memory of the vehicle.

[0104] Furthermore, a temperature sensor and a pressure sensor may be installed at the hot side channel inlet 21 to obtain the first temperature and the first pressure. According to the real-time values ​​of the first temperature and the first pressure, the density of the first medium at the hot side channel inlet 21 may be obtained by looking up the table.

[0105] Furthermore, since the first medium is a liquid, the volume flow rate of the first medium at the hot side channel inlet 21 can be obtained by multiplying the flow rate of the first medium at the hot side channel inlet 21 by the pipe cross-sectional area of ​​the hot side channel inlet 21. The flow rate of the first medium at the hot side channel inlet 21 can be measured by installing a flow sensor at the hot side channel inlet 21, and the pipe cross-sectional area of ​​the hot side channel inlet 21 is a fixed value, which can be obtained by those skilled in the art by measuring or referring to the corresponding size description of the product.

[0106] Furthermore, in the above step S32, it is necessary to obtain the mass flow value of the second medium, so the following describes how to obtain the mass flow of the second medium.

[0107] Specifically, the mass flow rate of the second medium is obtained by the following formula:

[0108] m cold =ρ coldin ×Q coldin ;

[0109] Among them, m cold is the mass flow rate of the second medium, ρ coldin is the density of the second medium at the cold side channel inlet 31, Q coldin is the volume flow rate of the second medium at the cold side channel inlet 31.

[0110] The density of the second medium at the hot side channel inlet 21 is obtained by:

[0111] Obtaining a third temperature of the second medium at the cold side channel inlet 31;

[0112] Obtaining a third pressure of the second medium at the cold side channel inlet 31;

[0113] The density of the second medium at the cold-side channel inlet 31 is obtained according to the physical properties of the second medium, the third temperature and the third pressure.

[0114] Specifically, the density of a substance is a fixed value under a specific pressure and temperature. Therefore, according to the specific substance type (coolant or air cooling) of the second medium, and the third temperature value and the third pressure value at the cold side channel inlet 31, the specific value of the density of the second medium can be obtained by looking up the table. The table can be pre-stored in the memory of the vehicle.

[0115] Furthermore, a temperature sensor and a pressure sensor may be installed at the cold side channel inlet 31 to obtain the third temperature and the third pressure. According to the real-time values ​​of the third temperature and the third pressure, the density of the first medium at the cold side channel inlet 31 may be obtained by looking up the table.

[0116] As described above, depending on the type of the heat exchanger 10, the second medium may be gas or liquid. The following describes how to obtain the volume flow when the second medium is gas or liquid.

[0117] When the second medium is gas, the volume flow rate of the second medium at the cold side channel inlet 31 can be obtained by multiplying the wind speed of the second medium at the cold side channel inlet 31 by the windward area of ​​the cold side channel inlet 31. The wind speed of the second medium at the cold side channel inlet 31 can be measured by installing a wind speed sensor at the cold side channel inlet 31, and the windward area of ​​the cold side channel inlet 31 is a fixed value, which can be obtained by those skilled in the art by measuring or checking the corresponding size description of the product.

[0118] When the second medium is a liquid, the volume flow rate of the second medium at the cold side channel inlet 31 can be obtained by multiplying the flow rate of the second medium at the cold side channel inlet 31 by the pipe diameter of the cold side channel inlet 31. The flow rate of the second medium at the cold side channel inlet 31 can be measured by installing a flow sensor at the cold side channel inlet 31. The pipe diameter of the cold side channel inlet 31 is a fixed value, which can be obtained by those skilled in the art by measuring or referring to the corresponding size description of the product.

[0119] It can be seen from the above content that in the technical solution of this embodiment, by installing temperature sensors and pressure sensors at the hot side channel inlet 21, the hot side channel outlet 22, and the cold side channel inlet 31 of the heat exchanger 10, installing a flow sensor at the hot side channel inlet 21, and installing a wind speed sensor or a flow sensor at the cold side channel inlet 31, and pre-store the specific enthalpy chart (which changes with pressure and temperature) of a specific substance, the specific heat capacity chart and the density chart in the memory, and according to the fixed size value of the heat exchanger 10, the heat exchange efficiency of the heat exchanger 10 can be obtained through simple logical calculation.

[0120] The above-mentioned pressure sensor, temperature sensor, flow sensor and wind speed sensor are low-cost and easy to install. Compared with the enthalpy difference experiment that requires setting up a large component stand in a specific experimental site, the difficulty of obtaining the heat transfer efficiency data of the heat exchanger 10 is greatly reduced.

[0121] In this embodiment, by directly obtaining the thermodynamic parameters of the first medium in the hot side channel 20 of the heat exchanger 10, and directly obtaining the thermodynamic parameters of the second medium in the cold side channel 30 of the heat exchanger 10, the calculated heat exchange efficiency of the heat exchanger 10 is closer to the actual operating state of the vehicle.

[0122] Therefore, the method for measuring the heat exchange efficiency of the heat exchanger of the present embodiment can be used to directly calculate the heat exchange efficiency of the heat exchanger 10 during the actual driving process of the vehicle, and provide the real-time heat exchange efficiency data to the vehicle thermal management system as a basis for the vehicle thermal management strategy. Furthermore, the method for measuring the heat exchange efficiency of the heat exchanger of the present embodiment can also test the heat exchange efficiency of the heat exchanger 10 under different driving conditions of the vehicle and different changes in external ambient temperature, and obtain heat exchange efficiency data. According to the heat exchange efficiency data under a specific vehicle form state and a specific external ambient temperature, a heat exchange efficiency chart (map) of the heat exchanger 10 is output, and the chart is stored in the vehicle's memory. The vehicle thermal management system can call the chart to obtain the heat exchange efficiency data under a specific vehicle form state and a specific external ambient temperature.

[0123] The present application also provides a computer-readable storage medium, on which a heat exchanger thermal efficiency calculation program is stored. When the heat exchanger thermal efficiency calculation program is executed by a processor, the above-mentioned heat exchange efficiency calculation method of the heat exchanger is implemented.

[0124] like Figure 4 and Figure 5 As shown, the present application also provides a heat exchanger heat exchange efficiency measurement system. According to the embodiment of the heat exchanger heat exchange efficiency measurement system of the present application, the heat exchanger 10, a first measurement component 100, a second measurement component 200, a third measurement component, and a calculation module are provided. Specifically:

[0125] The heat exchanger 10 includes a hot side channel 20 and a cold side channel 30 . A first medium flows through the hot side channel 20 , and a second medium flows through the cold side channel 30 .

[0126] The first measuring assembly 100 is disposed at the hot side channel inlet 21 of the heat exchanger 10, and is used to measure the first temperature, first pressure and flow rate of the first medium at the hot side channel inlet 21. The flow rate here is a volume flow rate.

[0127] Specifically, the first measuring component 100 measures the real-time first temperature value, real-time first pressure value and real-time flow value of the first medium at the hot side channel inlet 21, and transmits these three values ​​to the calculation module of the above-mentioned heat exchanger thermal efficiency measurement system. When the calculation module calculates the thermal efficiency of the heat exchanger 10, these three parameters can be called.

[0128] Further, the second measuring component 200 is disposed at the hot side channel outlet 22 of the heat exchanger 10 , and the second measuring component 200 is used to measure the second temperature and the second pressure of the first medium at the hot side channel outlet 22 .

[0129] Specifically, the second measuring component 200 measures the real-time second temperature value and the real-time second pressure value of the first medium at the hot side channel outlet 22, and transmits these two values ​​to the calculation module of the above-mentioned heat exchanger thermal efficiency measurement system. When the calculation module calculates the thermal efficiency of the heat exchanger 10, these two parameters can be called.

[0130] Further, the third measuring assembly 300 is disposed at the cold side channel inlet 31 of the heat exchanger, and the third measuring assembly 300 is used to measure the third temperature, third pressure and flow rate of the second medium at the cold side channel inlet 31. And the flow rate here is the volume flow rate.

[0131] Specifically, the third measuring component 300 measures the real-time third temperature value, real-time third pressure value and flow rate of the second medium at the cold side channel inlet 31, and transmits these three values ​​to the calculation module of the above-mentioned heat exchanger heat transfer efficiency measurement system. When the calculation module calculates the heat transfer efficiency of the heat exchanger 10, these three parameters can be called.

[0132] The calculation module is in communication connection with the first measurement component 100 , the second measurement component 200 and the third measurement component 300 , and the calculation module is used to execute the above-mentioned measurement method.

[0133] Specifically, the parameters obtained by the first measuring component 100, the second measuring component 200 and the third measuring component 300 can be transmitted to the calculation module. When the calculation module executes the above-mentioned measurement method, the parameters are operated by the above-mentioned formulas to calculate the heat exchange efficiency of the heat exchanger 10.

[0134] Furthermore, in the technical solution of this embodiment, the heat exchanger heat transfer efficiency measurement system further includes a storage device, which is communicatively connected to the calculation module, and stores a first physical property chart of the first medium and a second physical property chart of the second medium.

[0135] Specifically, the content of the first physical property diagram at least includes the specific enthalpy, specific heat capacity and density of the first medium at different temperatures and pressures.

[0136] Specifically, the content of the second physical property diagram includes at least the specific enthalpy, specific heat capacity and density of the second medium at different temperatures and pressures.

[0137] When the calculation module executes the above-mentioned measurement method and performs calculations according to various formulas, it can call the parameters in the first physical property chart and the second physical property chart.

[0138] Optionally, when the calculation module executes step S21 of the above-mentioned measurement method, the calculation module can retrieve the specific enthalpy of the first medium at the hot side channel inlet 21 in the first physical property diagram according to the first temperature and the first pressure measured by the first measurement component 100.

[0139] Optionally, when the calculation module executes step S21 of the above-mentioned measurement method, the calculation module can retrieve the specific enthalpy of the first medium at the hot side channel outlet 22 in the first physical property diagram according to the second temperature and the second pressure measured by the first measurement component 100.

[0140] Optionally, when the calculation module executes step S31 of the above-mentioned measurement method, the calculation module can retrieve the specific heat capacity of the first medium at the hot side channel inlet 21 in the first physical property diagram according to the first temperature and the first pressure measured by the first measurement component 100.

[0141] Optionally, when the calculation module executes step S32 of the above-mentioned measurement method, the calculation module can retrieve the specific heat capacity of the second medium at the cold side channel inlet 31 in the second physical property diagram according to the third temperature and the third pressure measured by the third measurement component 300.

[0142] Optionally, when the calculation module executes step S21 and step S31 of the above-mentioned measurement method, the calculation module can retrieve the density of the first medium at the hot side channel inlet 21 in the first physical property diagram according to the first temperature and the first pressure measured by the first measurement component 100.

[0143] Optionally, when the calculation module executes step S32 of the above-mentioned measurement method, the calculation module can retrieve the density of the second medium at the cold side channel inlet 31 in the second physical property diagram according to the third temperature and the third pressure measured by the third measurement component 300 .

[0144] In addition, the various parameters measured by the first measurement component 100, the second measurement component 200 and the third measurement component 300 can be directly transmitted to the calculation module, or they can be first transmitted to the storage for storage, and then the calculation module calls the various parameters stored in the storage when executing the above-mentioned measurement method.

[0145] Further, as described above, the heat exchanger 10 may be an air-cooled heat exchanger or a liquid-cooled heat exchanger, and thus the heat exchange efficiency measurement system of the heat exchanger in this embodiment also includes two embodiments.

[0146] Embodiment 1:

[0147] like Figure 4 As shown, the heat exchanger 10 of the first embodiment is an air-cooled heat exchanger, the first measuring component 100 includes a first temperature sensor 101, a first pressure sensor 102 and a first flow sensor 103, the second measuring component 200 includes a second temperature sensor 201 and a second pressure sensor 202. The third measuring component 300 includes a third temperature sensor 301, a third pressure sensor 302 and a wind speed sensor 303.

[0148] Specifically, the first temperature sensor 101 and the first pressure sensor 102 are arranged at the hot side channel inlet 21 of the heat exchanger, and are used to measure the above-mentioned first temperature and first pressure, and transmit these two data to the calculation module, or upload them to the memory.

[0149] Furthermore, the first flow sensor 103 is disposed at the hot side channel inlet 21 for measuring the flow of the first medium at the hot side channel inlet 21 and transmitting the data to the calculation module or uploading it to the memory.

[0150] Furthermore, a second temperature sensor 201 and a second pressure sensor 202 are arranged at the hot side channel outlet 22 to measure the second temperature and the second pressure, and transmit the two data to the calculation module or upload them to the memory.

[0151] Furthermore, a third temperature sensor 301 and a third pressure sensor 302 are arranged at the cold side channel inlet 31, that is, at the windward side of the heat exchanger 10, for measuring the third temperature and the fourth temperature mentioned above, and transmitting these two data to the calculation module, or uploading them to the memory.

[0152] Furthermore, the wind speed sensor 303 is arranged at the cold side channel inlet 31, that is, at the windward surface of the heat exchanger 10, for measuring the wind speed of the second medium at the windward surface of the heat exchanger 10, and uploading the data to the calculation module, or uploading to the memory.

[0153] Embodiment 2:

[0154] like Figure 5 As shown, the heat exchanger 10 of the second embodiment is a liquid-cooled heat exchanger, the first measuring component 100 includes a first temperature sensor 101, a first pressure sensor 102 and a first flow sensor 103, the second measuring component 200 includes a second temperature sensor 201 and a second pressure sensor 202, and the third measuring component 300 includes a third temperature sensor 301, a third pressure sensor 302 and a second flow sensor 304.

[0155] In the second embodiment, the first temperature sensor 101, the first pressure sensor 102, the first flow sensor 103, the second temperature sensor 201, the second pressure sensor 202, the third temperature sensor 301, and the third pressure sensor 302 are consistent with those in the first embodiment described above. The difference is that the wind speed sensor 303 in the first embodiment described above is replaced with a second flow sensor to measure the flow of the liquid second medium at the cold side channel inlet 31.

[0156] The present application also provides a vehicle. According to an embodiment of the vehicle of the present application, the vehicle includes the above-mentioned heat exchanger heat transfer efficiency measurement system.

[0157] Optionally, the vehicle is a new energy electric vehicle.

[0158] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for measuring the heat exchange efficiency of a heat exchanger, characterized in that: The heat exchanger (10) comprises a hot side channel (20) and a cold side channel (30), a first medium flows through the hot side channel (20), and a second medium flows through the cold side channel (30), and the measuring method comprises: Obtaining a temperature difference between the first medium at a hot side channel inlet (21) and the second medium at a cold side channel inlet (31); obtaining a heat exchange amount after the first medium flows through the hot side channel (20); Obtaining a first heat capacity rate of the first medium at the hot side channel inlet (21), and obtaining a second heat capacity rate of the second medium at the cold side channel inlet (31); According to the temperature difference, the heat exchange amount, the first heat capacity ratio and the second heat capacity ratio, the heat exchange efficiency of the heat exchanger is obtained by the following formula: Wherein, ∈ is the heat exchange efficiency of the heat exchanger, φ is the heat exchange amount after the first medium flows through the hot side channel (20), and C min is the minimum value of the first heat capacity ratio and the second heat capacity ratio, the T hotin -T coldin It is the temperature difference between the first medium at the hot side channel inlet (21) and the second medium at the cold side channel inlet (31).

2. The measuring method according to claim 1, characterized in that: The heat exchange amount of the first medium after flowing through the hot side channel (20) is obtained by the following formula: φ=m hot ×(h hotin - / h hotout ); Wherein, φ is the heat exchange capacity of the first medium after flowing through the hot side channel (20), and m hot is the mass flow rate of the first medium, and h hotin is the specific enthalpy of the first medium at the inlet (21) of the hot side channel, and the h hotout is the specific enthalpy of the first medium at the hot side channel outlet (22).

3. The measuring method according to claim 2, characterized in that: The measuring method further comprises: Obtaining a first temperature of the first medium at the hot side channel inlet (21); Obtaining a first pressure of the first medium at the hot side channel inlet (21); Obtaining a second temperature of the first medium at the hot side channel outlet (22); Obtaining a second pressure of the first medium at the hot side channel outlet (22); Obtaining a specific enthalpy of the first medium at the hot side channel inlet (21) according to the physical properties of the first medium, the first temperature and the first pressure; According to the physical properties of the first medium, the second temperature and the second pressure, the specific enthalpy of the first medium at the hot side channel outlet (22) is obtained.

4. The measuring method according to claim 1, characterized in that: The first heat capacity ratio is obtained by the following formula: C hot =C hotin ×m hot ; Among them, the C hot is the first heat capacity, the c hotin is the specific heat capacity of the first medium at the inlet (21) of the hot side channel, and the m hot is the mass flow rate of the first medium.

5. The measuring method according to claim 1, characterized in that: The second heat capacity ratio is obtained by the following formula: C cold =c coldin ×m cold ; Among them, the C cold is the second heat capacity, the c coldin is the specific heat capacity of the second medium at the inlet (31) of the cold side channel, and the m cold is the mass flow rate of the second medium.

6. The measuring method according to claim 4, characterized in that: The measuring method further comprises: Obtaining a first temperature of the first medium at the hot side channel inlet (21); Obtaining a first pressure of the first medium at the hot side channel inlet (21); According to the physical properties of the first medium, the first temperature and the first pressure, the specific heat capacity of the first medium at the hot side channel inlet (21) is obtained.

7. The measuring method according to claim 5, characterized in that: The measuring method further comprises: Obtaining a third temperature of the second medium at the cold side channel inlet (31); Obtaining a third pressure of the second medium at the cold side channel inlet (31); According to the physical properties of the second medium, the third temperature and the third pressure, the specific heat capacity of the second medium at the cold side channel inlet (31) is obtained.

8. The measuring method according to claim 2 or 4, characterized in that: The mass flow rate of the first medium is obtained by the following formula: m hot =ρ hotin ×Q hotin ; Among them, the m hot is the mass flow rate of the first medium, and ρ hotin is the density of the first medium at the inlet (21) of the hot side channel, and Q hotin is the volume flow rate of the first medium at the hot side channel inlet (21).

9. The measuring method according to claim 8, characterized in that: The measuring method further comprises: Obtaining a first temperature of the first medium at the hot side channel inlet (21); Obtaining a first pressure of the first medium at the hot side channel inlet (21); The density of the first medium at the hot side channel inlet (21) is obtained according to the physical properties of the first medium, the first temperature and the first pressure.

10. The measuring method according to claim 5, characterized in that: The mass flow rate of the second medium is obtained by the following formula: m cold =ρ coldin ×Q coldin ; Among them, the m cold is the mass flow rate of the second medium, the ρ coldin is the density of the second medium at the inlet (31) of the cold side channel, and Q coldin is the volume flow rate of the second medium at the cold side channel inlet (31).

11. The measuring method according to claim 10, characterized in that: The measuring method further comprises: Obtaining a third temperature of the second medium at the cold side channel inlet (31); Obtaining a third pressure of the second medium at the cold side channel inlet (31); The density of the second medium at the cold side channel inlet (31) is obtained according to the physical properties of the second medium, the third temperature and the third pressure.

12. A computer-readable storage medium, characterized in that: A heat exchange efficiency calculation program for the heat exchanger is stored thereon, and when the heat exchange efficiency calculation program for the heat exchanger is executed by a processor, a method for measuring the heat exchange efficiency of the heat exchanger according to any one of claims 1 to 11 is implemented.

13. A heat exchanger heat transfer efficiency measurement system, characterized in that: include: A heat exchanger (10) comprises a hot side channel (20) and a cold side channel (30), wherein a first medium flows through the hot side channel (20) and a second medium flows through the cold side channel (30); A first measuring component (100) is arranged at a hot side channel inlet (21) of the heat exchanger (10), wherein the first measuring component (100) is used to measure a first temperature, a first pressure and a flow rate of a first medium at the hot side channel inlet (21); A second measuring component (200) is disposed at a hot side channel outlet (22) of the heat exchanger (10), the second measuring component (200) being used to measure a second temperature and a second pressure of the first medium at the hot side channel outlet (22); A third measuring component (300) is arranged at the cold side channel inlet (31) of the heat exchanger, and the third measuring component (300) is used to measure a third temperature, a third pressure and a flow rate of the second medium at the cold side channel inlet (31); A computing module is communicatively connected to the first measuring component (100), the second measuring component (200) and the third measuring component (300), and the computing module is used to execute any one of the measuring methods 1 to 12.

14. The heat exchange efficiency measurement system of heat exchanger according to claim 13, characterized in that: The device further comprises a storage device, the storage device is in communication connection with the computing module, and the storage device stores a first physical property chart of the first medium. The calculation module is capable of retrieving the specific enthalpy of the first medium at the hot side channel inlet (21) from the first physical property chart according to the first temperature and the first pressure; and / or, The calculation module can retrieve the specific enthalpy of the first medium at the hot side channel outlet (22) from the first physical property chart according to the second temperature and the second pressure.

15. The heat exchange efficiency measurement system of heat exchanger according to claim 13, characterized in that: The device further comprises a storage device, the storage device being in communication connection with the computing module, the storage device storing a first physical property chart of the first medium and a second physical property chart of the second medium. The calculation module is capable of retrieving the specific heat capacity of the first medium at the hot side channel inlet (21) from the first physical property chart according to the first temperature and the first pressure; and / or, The calculation module can retrieve the specific heat capacity of the second medium at the cold side channel inlet (31) from the second physical property chart according to the third temperature and the third pressure.

16. The heat exchange efficiency measurement system of heat exchanger according to claim 13, characterized in that: The device further comprises a storage device, the storage device being in communication connection with the computing module, the storage device storing a first physical property chart of the first medium and a second physical property chart of the second medium. The calculation module is capable of retrieving the density of the first medium at the hot side channel inlet (21) in the first physical property chart according to the first temperature and the first pressure; and / or, The calculation module can retrieve the density of the second medium at the cold side channel inlet (31) in the second physical property chart according to the third temperature and the third pressure.

17. The heat exchange efficiency measurement system of a heat exchanger according to claim 13, characterized in that: The heat exchanger (10) is an air-cooled heat exchanger, the first measuring component (100) comprises a first temperature sensor (101), a first pressure sensor (102) and a first flow sensor (103), the second measuring component (200) comprises a second temperature sensor (201) and a second pressure sensor (202), and the third measuring component (300) comprises a third temperature sensor (301), a third pressure sensor (302) and a wind speed sensor (303).

18. The heat exchange efficiency measurement system of a heat exchanger according to claim 13, characterized in that: The heat exchanger (10) is a liquid-cooled heat exchanger, the first measuring component (100) comprises a first temperature sensor (101), a first pressure sensor (102) and a first flow sensor (103), the second measuring component (200) comprises a second temperature sensor (201) and a second pressure sensor (202), and the third measuring component (300) comprises a third temperature sensor (301), a third pressure sensor (302) and a second flow sensor (304).

19. A vehicle, characterized in that: The heat exchange efficiency measurement system of a heat exchanger comprises the heat exchange efficiency measurement system of any one of claims 13 to 18.

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