Flow control method and device based on PTC heater

Abstract

The invention provides a flow control method and device based on a PTC heater, the method is applied to a controller of a vehicle-mounted heating device, the vehicle-mounted heating device comprises the PTC heater, the controller is in communication connection with the PTC heater, and the method comprises the steps that the inlet and outlet temperature difference and the heating power of the PTC heater are obtained regularly; the performance parameters, the heating power and the inlet and outlet temperature difference of the cooling liquid are input into a preset flow calculation formula, and the corresponding cooling liquid flow is obtained through calculation; and obtaining an output value of the working parameter according to a pre-stored corresponding relationship between the cooling liquid flow and the working parameter under different output temperature differences so as to control the output temperature of the PTC heater according to the output value. According to the embodiment of the invention, the cooling liquid flow can be obtained through low-cost calculation, and a cooling liquid flow meter assembly is reduced; in addition, the output temperature of the PTC heater can be controlled according to the output value, and the heating efficiency of the PTC heater is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of PTC heaters, and in particular to a flow control method and device based on a PTC heater. Background Art

[0002] PTC (Positive Temperature Coefficient) heaters are also called PTC heating elements. They are composed of PTC ceramic heating elements and aluminum tubes. PTC heaters have the advantages of low thermal resistance and high heat exchange efficiency. They are mostly used in vehicle systems to provide heat energy for batteries and passengers in low temperature environments. With the advancement of technology, the performance requirements of electronic devices are getting higher and higher. Therefore, how to accurately adjust the output temperature of PTC heaters has become an urgent problem to be solved.

[0003] The output temperature of the PTC heater is affected by factors such as the coolant flow rate. In the prior art, the coolant flow rate is obtained by using a dedicated flow meter to accurately adjust the output temperature of the PTC heater according to the obtained coolant flow rate. However, the flow meter is expensive, and there is a problem of high investment cost when using the flow meter to obtain the coolant flow rate.

[0004] Therefore, the existing flow calculation method has the problem of high investment cost. Summary of the invention

[0005] The embodiment of the present invention provides a flow control method and device based on a PTC heater, aiming to solve the problem of high investment cost in the existing flow calculation method.

[0006] In a first aspect, an embodiment of the present invention provides a flow control method based on a PTC heater, the method is applied to a controller of a vehicle-mounted heating device, the vehicle-mounted heating device includes a PTC heater, the controller is communicatively connected with the PTC heater, and the method includes: Regularly obtain the inlet and outlet temperature difference and heating power of the PTC heater; Input the performance parameters of the coolant, the heating power and the inlet and outlet temperature difference into a preset flow calculation formula to calculate and obtain the corresponding coolant flow; According to the pre-stored correspondence between the coolant flow rate and the working parameter at different output temperature differences, the output value of the working parameter is obtained to control the output temperature of the PTC heater according to the output value.

[0007] In a second aspect, an embodiment of the present invention further provides a flow control device based on a PTC heater, wherein the device is configured in a controller of a vehicle-mounted heating device, wherein the vehicle-mounted heating device includes a PTC heater, wherein the controller is communicatively connected with the PTC heater, and wherein the device includes: An acquisition unit, used for regularly acquiring the inlet and outlet temperature difference and heating power of the PTC heater; A calculation unit, used for inputting the performance parameters of the coolant, the heating power and the inlet and outlet temperature difference into a preset flow calculation formula to calculate and obtain the corresponding coolant flow; The control unit is used to obtain the output value of the working parameter according to the pre-stored correspondence between the coolant flow rate and the working parameter under different output temperature differences so as to control the output temperature of the PTC heater according to the output value.

[0008] The present invention provides a flow control method and device based on a PTC heater. The method is applied to a controller of a vehicle-mounted heating device, wherein the vehicle-mounted heating device includes a PTC heater, and the controller is communicatively connected with the PTC heater. The method includes: regularly obtaining the inlet and outlet temperature difference and the heating power of the PTC heater; inputting the performance parameters of the coolant, the heating power and the inlet and outlet temperature difference into a preset flow calculation formula to calculate and obtain the corresponding coolant flow; and according to the pre-stored correspondence between the coolant flow and the working parameters under different output temperature differences, obtaining the output value of the working parameter to control the output temperature of the PTC heater according to the output value. The embodiment of the present invention can calculate and obtain the corresponding coolant flow rate by inputting the performance parameters of the coolant, the heating power and the inlet and outlet temperature difference into a preset flow calculation formula, thereby realizing low-cost calculation and acquisition of the coolant flow rate; further, compared with the use of a dedicated flow meter to obtain the coolant flow rate in the prior art, the embodiment of the present invention can reduce the coolant flow meter assembly and reduce the coolant flow rate calculation cost; the embodiment of the present invention can also obtain the output value of the working parameter according to the correspondence between the pre-stored coolant flow rate and the working parameter under different output temperature differences to control the output temperature of the PTC heater according to the output value, thereby realizing precise control of the output temperature of the PTC heater, improving the heating efficiency of the PTC heater, and making the real-time output temperature of the PTC heater reach the target output temperature as quickly as possible, ensuring the stability of the real-time output temperature and meeting the heating requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0010] Figure 1 A schematic flow chart of a flow control method based on a PTC heater provided in an embodiment of the present invention; Figure 2 A schematic block diagram of a flow control device based on a PTC heater provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0011] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0012] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0013] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0014] It should be further understood that the term "and / or" used in the present specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations. The embodiment of the present invention provides a flow control method and device based on a PTC heater. The flow control method based on a PTC heater can be found in Figure 1 , Figure 1 A flow chart of a flow control method based on a PTC heater provided in an embodiment of the present invention. The method is applied to a controller of a vehicle-mounted heating device, the vehicle-mounted heating device includes a PTC heater, and the controller is in communication connection with the PTC heater.

[0015] Figure 1The flow chart of the flow control method based on the PTC heater provided in the embodiment of the present invention is as follows. Figure 1 As shown, the method comprises steps S110-S130.

[0016] S110, regularly obtaining the inlet and outlet temperature difference and heating power of the PTC heater.

[0017] In this embodiment, the vehicle heating system includes a PTC heater, a water pump and a circulation pipe, the PTC heater is connected to the water pump through the circulation pipe; there is coolant in the circulation pipe; the water pump is used to drive the movement of the coolant; and the PTC heater is used to heat the coolant.

[0018] The inlet and outlet temperature difference and the heating power of the PTC heater are obtained regularly; specifically, the inlet and outlet temperature difference and the heating power of the PTC heater are obtained every preset time period, and the preset time period can be set according to actual application, and the preset time period can be set to 100 microseconds.

[0019] The heating power is the power value output by the PTC heater itself, and the power value is the effective power value. The heating power is obtained based on the theoretical heating power and heating efficiency of the PTC heater. For example, the theoretical heating power of the PTC heater is 7KW, and the heating efficiency is 95%, then the heating power Q of the PTC heater is 6.65KW, and the specific calculation formula is: Q = (7×0.95) KW = 6.65KW. In addition, the heating power can also be calculated by detecting the actual voltage value and the actual current value of the PTC heater according to the actual voltage value and the actual current value.

[0020] Furthermore, a temperature sensor may be used to obtain an inlet and outlet temperature difference of the PTC heater; wherein, the inlet and outlet temperature difference = | coolant temperature at the water inlet of the PTC heater - coolant temperature at the water outlet of the PTC heater |.

[0021] In one embodiment, step S110 includes: regularly acquiring a first coolant temperature collected by a first temperature sensor and a second coolant temperature collected by a second temperature sensor; wherein the first temperature sensor is arranged at the water inlet of the PTC heater, and the second temperature sensor is arranged at the water outlet of the PTC heater; and taking the difference between the first coolant temperature and the second coolant temperature as the inlet and outlet temperature difference.

[0022] In this embodiment, the first temperature sensor obtains the coolant temperature at the water inlet of the PTC heater and provides it to the controller; the second temperature sensor obtains the coolant temperature at the water outlet of the PTC heater and provides it to the controller; the controller can calculate the inlet and outlet temperature difference based on the first coolant temperature and the second coolant temperature.

[0023] S120, inputting the performance parameters of the coolant, the heating power and the inlet and outlet temperature difference into a preset flow calculation formula to calculate and obtain the corresponding coolant flow.

[0024] In this embodiment, the performance parameters of the coolant, the heating power Q and the inlet and outlet temperature difference are Input into the preset flow calculation formula to calculate the corresponding coolant flow Vs; the performance parameters of the coolant come from the coolant supplier, and the performance parameters include the constant pressure specific heat capacity Cp and specific weight r of the coolant; specifically, the coolant can be a 50% ethylene glycol solution, the constant pressure specific heat capacity of the 50% ethylene glycol solution is about 3.5KJ / Kg·℃, and the specific weight of the 50% ethylene glycol solution is about 1113Kg / m 3 .

[0025] The flow calculation formula is: ; Where Vs is the coolant flow rate, Q is the heating power, Cp is the constant pressure specific heat capacity, r is the specific weight, is the inlet and outlet temperature difference.

[0026] The embodiment of the present invention can calculate and obtain the corresponding coolant flow rate by inputting the performance parameters of the coolant, the heating power and the inlet and outlet temperature difference into a preset flow calculation formula, thereby realizing low-cost calculation and acquisition of the coolant flow rate; further, compared with the use of a dedicated flow meter to obtain the coolant flow rate in the prior art, the embodiment of the present invention can reduce the coolant flow meter assembly and reduce the coolant flow rate calculation cost.

[0027] In one embodiment, before step S120, the method further includes: performing unit conversion on the performance parameter and / or the heating power according to the target measurement unit.

[0028] In this embodiment, before the performance parameters of the coolant, the heating power and the inlet and outlet temperature difference are input into the preset flow calculation formula, it is necessary to convert the performance parameters and / or the heating power according to the target measurement unit; the target measurement unit can be the measurement unit of the coolant flow, and the target measurement unit can be set to m 3 / h; For example, the heating power of the PTC heater is 6.65KW. At this time, the measurement unit of the heating power does not match the target measurement unit. Therefore, it is necessary to calculate the heating power according to the target measurement unit m 3 / h to convert its unit, the specific conversion formula is: Q = 6.65×3600KJ / h = 23940KJ / h; where Q is the heating power.

[0029] In one embodiment, after step S120, the method further includes: determining a target coolant flow rate of the PTC heater, acquiring multiple coolant flow rates within a preset statistical period and calculating an average value to obtain the target coolant flow rate.

[0030] In this embodiment, in order to accurately adjust the output temperature of the PTC heater, the speed of the water pump can be dynamically adjusted according to the target coolant flow rate; wherein, the coolant flow rate can be adjusted by adjusting the speed of the water pump, and the output temperature of the PTC heater can be adjusted by adjusting the coolant flow rate; the target coolant flow rate is the average of multiple coolant flow rates within a preset statistical period; the statistical period can be set according to actual applications, wherein the statistical period is greater than the preset time length, the statistical period is an integer multiple of the preset time length, and the statistical period can be set to 1 second.

[0031] In one embodiment, after step S120, the method further includes: determining whether the coolant flow rate is within a preset flow rate range; if not within the preset flow rate range, outputting corresponding flow abnormality prompt information.

[0032] In this embodiment, it is determined whether the coolant flow rate is within a preset flow rate range; the preset flow rate range can be set according to actual applications; if within the preset flow rate range, the rotation speed of the water pump is dynamically adjusted according to the coolant flow rate; specifically, the rotation speed of the water pump can be dynamically adjusted according to the set output temperature and the coolant flow rate; wherein, the coolant flow rate can be adjusted by adjusting the rotation speed of the water pump, and the output temperature of the PTC heater can be adjusted by adjusting the coolant flow rate, thereby achieving precise control of the output temperature of the PTC heater to meet heating requirements.

[0033] If it is not within the preset flow range, the corresponding flow abnormality prompt information is output, and the flow abnormality prompt information may be "coolant flow abnormality" or the like; specifically, the flow abnormality prompt information is displayed on a designated interface to prompt the user.

[0034] In one embodiment, after determining whether the coolant flow is within a preset flow range, it also includes: if it is not within the preset flow range, determining whether the coolant flow is greater than a preset flow threshold; if so, outputting a first abnormal prompt message; if not, outputting a second abnormal prompt message and / or controlling the PTC heater to stop heating.

[0035] In this embodiment, if the coolant flow rate is not within the preset flow rate range, it is determined whether the coolant flow rate is greater than a preset flow rate threshold; the preset flow rate threshold is greater than or equal to the maximum value in the preset flow rate range, and the preset flow rate threshold can be set according to actual applications; when the coolant flow rate is greater than the preset flow rate threshold, the coolant pressure in the circulation pipeline is high, which can easily cause damage to the device. At this time, a first abnormal prompt message is output to prompt the user, and the user can reduce the speed of the water pump or turn off the PTC heater according to the first abnormal prompt message; the first abnormal prompt message can be "the pipeline pressure is high, please reduce or turn off the PTC heater, etc."

[0036] When the coolant flow rate is not within the preset flow rate range and is not greater than the preset flow rate threshold, it is determined that the PTC heater is in a dry-burning state. In order to prevent device damage, it is necessary to output a second abnormal prompt message and / or control the PTC heater to stop heating; wherein, the second abnormal prompt message is "PTC heater is dry-burning, please turn off the PTC heater or add coolant".

[0037] In one embodiment, after step S120, it also includes: obtaining a theoretical coolant flow rate based on operating parameters and characteristic data of the water pump; determining whether a difference between the coolant flow rate and the theoretical coolant flow rate is within a preset difference range; if not within the preset difference range, outputting a third abnormal prompt information.

[0038] In this embodiment, a theoretical coolant flow rate is obtained based on the operating parameters and characteristic data of the water pump; it is determined whether the difference between the coolant flow rate and the theoretical coolant flow rate is within a preset difference range; if within the preset difference range, subsequent operations are performed, for example, dynamically adjusting the rotation speed of the water pump based on the coolant flow rate, or obtaining a coolant flow rate compensation value based on the difference, and dynamically adjusting the rotation speed of the water pump based on the coolant flow rate compensation value and the coolant flow rate.

[0039] If it is not within the preset difference range, it means that the coolant in the circulation pipeline is insufficient, and a third abnormal prompt message is output to prompt the user. The third abnormal prompt message may be "Insufficient coolant, please refill" or the like.

[0040] S130. According to the pre-stored correspondence between the coolant flow rate and the working parameter at different output temperature differences, obtain the output value of the working parameter to control the output temperature of the PTC heater according to the output value.

[0041] In this embodiment, the controller is communicatively connected to the vehicle control end of the whole vehicle; specifically, the vehicle controller is communicatively connected to the controller via a LIN transceiver and a digital isolation chip, and the transmission of signals or energy between the vehicle controller and the controller is realized by using a LIN transceiver and a digital isolation chip; according to the correspondence between the coolant flow rate and the working parameters under different output temperature differences stored in advance, before obtaining the output value of the working parameter, it is necessary to obtain the target output temperature from the vehicle controller in real time or at a fixed time; wherein the target output temperature is the output temperature of the PTC heater set by the vehicle controller; at the same time, the real-time output temperature of the PTC heater is collected in real time using a temperature sensor; the output temperature difference is calculated based on the target output temperature and the real-time output temperature; according to the correspondence between the coolant flow rate and the working parameters under different output temperature differences stored in advance, the output value of the working parameter is obtained; the speed of the water pump is adjusted according to the output value to realize the control according to the output value. The coolant flow dynamically adjusts the rotation speed of the water pump, thereby indirectly achieving precise control of the output temperature of the PTC heater, improving the heating efficiency of the PTC heater, and making the real-time output temperature of the PTC heater reach the target output temperature as quickly as possible, ensuring the stability of the real-time output temperature and meeting the heating requirements; for example, if the output temperature difference is greater than the preset maximum output temperature difference threshold, then according to the correspondence between the coolant flow and the working parameter under different output temperature differences stored in advance, the output value of the working parameter is obtained to adjust the rotation speed of the water pump according to the output value, and when the rotation speed of the water pump is adjusted according to the output value, the heating efficiency of the PTC heater reaches the highest; further, in order to make the real-time output temperature of the PTC heater reach the target output temperature as quickly as possible, while adjusting the rotation speed of the water pump, the heating power of the PTC heater can also be dynamically adjusted according to the output temperature difference to improve the heating efficiency of the PTC heater.

[0042] In summary, the embodiment of the present invention can calculate and obtain the corresponding coolant flow rate by inputting the performance parameters of the coolant, the heating power and the inlet and outlet temperature difference into a preset flow calculation formula, thereby realizing low-cost calculation and acquisition of the coolant flow rate; further, compared with the use of a dedicated flow meter to obtain the coolant flow rate in the prior art, the embodiment of the present invention can reduce the coolant flow meter assembly and reduce the coolant flow rate calculation cost; the embodiment of the present invention can also obtain the output value of the working parameter according to the correspondence between the pre-stored coolant flow rate and the working parameter under different output temperature differences to control the output temperature of the PTC heater according to the output value, thereby realizing precise control of the output temperature of the PTC heater, improving the heating efficiency of the PTC heater, and making the real-time output temperature of the PTC heater reach the target output temperature as quickly as possible, ensuring the stability of the real-time output temperature and meeting the heating requirements.

[0043] Figure 2 Schematic block diagram of a flow control device based on a PTC heater provided in an embodiment of the present invention. Figure 2 As shown, corresponding to the above flow control method based on PTC heater, the present invention also provides a flow control device based on PTC heater, the device is configured in the controller of the vehicle heating device, the vehicle heating device includes a PTC heater, and the controller is connected to the PTC heater for communication. Figure 2 , the flow control device 700 based on the PTC heater comprises: The acquisition unit 701 is used to regularly acquire the inlet and outlet temperature difference and heating power of the PTC heater.

[0044] In this embodiment, the vehicle heating system includes a PTC heater, a water pump and a circulation pipe, the PTC heater is connected to the water pump through the circulation pipe; there is coolant in the circulation pipe; the water pump is used to drive the movement of the coolant; and the PTC heater is used to heat the coolant.

[0045] The inlet and outlet temperature difference and the heating power of the PTC heater are obtained regularly; specifically, the inlet and outlet temperature difference and the heating power of the PTC heater are obtained every preset time period, and the preset time period can be set according to actual application, and the preset time period can be set to 100 microseconds.

[0046] The heating power is the power value output by the PTC heater itself, and the power value is the effective power value. The heating power is obtained based on the theoretical heating power and heating efficiency of the PTC heater. For example, the theoretical heating power of the PTC heater is 7KW, and the heating efficiency is 95%, then the heating power Q of the PTC heater is 6.65KW, and the specific calculation formula is: Q = (7×0.95) KW = 6.65KW. In addition, the heating power can also be calculated by detecting the actual voltage value and the actual current value of the PTC heater according to the actual voltage value and the actual current value.

[0047] Furthermore, a temperature sensor may be used to obtain an inlet and outlet temperature difference of the PTC heater; wherein, the inlet and outlet temperature difference = | coolant temperature at the water inlet of the PTC heater - coolant temperature at the water outlet of the PTC heater |.

[0048] The calculation unit 702 is used to input the performance parameters of the coolant, the heating power and the inlet and outlet temperature difference into a preset flow calculation formula to calculate and obtain the corresponding coolant flow.

[0049] In this embodiment, the performance parameters of the coolant, the heating power Q and the inlet and outlet temperature difference are Input into the preset flow calculation formula to calculate the corresponding coolant flow Vs; the performance parameters of the coolant come from the coolant supplier, and the performance parameters include the constant pressure specific heat capacity Cp and specific weight r of the coolant; specifically, the coolant can be a 50% ethylene glycol solution, the constant pressure specific heat capacity of the 50% ethylene glycol solution is about 3.5KJ / Kg·℃, and the specific weight of the 50% ethylene glycol solution is about 1113Kg / m 3 .

[0050] The flow calculation formula is: ; Where Vs is the coolant flow rate, Q is the heating power, Cp is the constant pressure specific heat capacity, r is the specific weight, is the inlet and outlet temperature difference.

[0051] The embodiment of the present invention can calculate and obtain the corresponding coolant flow rate by inputting the performance parameters of the coolant, the heating power and the inlet and outlet temperature difference into a preset flow calculation formula, thereby realizing low-cost calculation and acquisition of the coolant flow rate; further, compared with the use of a dedicated flow meter to obtain the coolant flow rate in the prior art, the embodiment of the present invention can reduce the coolant flow meter assembly and reduce the coolant flow rate calculation cost.

[0052] The control unit 703 is used to obtain the output value of the working parameter according to the pre-stored correspondence between the coolant flow rate and the working parameter at different output temperature differences, so as to control the output temperature of the PTC heater according to the output value.

[0053] In this embodiment, the controller is communicatively connected to the vehicle control end of the whole vehicle; specifically, the vehicle controller is communicatively connected to the controller via a LIN transceiver and a digital isolation chip, and the transmission of signals or energy between the vehicle controller and the controller is realized by using a LIN transceiver and a digital isolation chip; according to the correspondence between the coolant flow rate and the working parameters under different output temperature differences stored in advance, before obtaining the output value of the working parameter, it is necessary to obtain the target output temperature from the vehicle controller in real time or at a fixed time; wherein the target output temperature is the output temperature of the PTC heater set by the vehicle controller; at the same time, the real-time output temperature of the PTC heater is collected in real time using a temperature sensor; the output temperature difference is calculated based on the target output temperature and the real-time output temperature; according to the correspondence between the coolant flow rate and the working parameters under different output temperature differences stored in advance, the output value of the working parameter is obtained; the speed of the water pump is adjusted according to the output value to realize the control according to the output value. The coolant flow dynamically adjusts the rotation speed of the water pump, thereby indirectly achieving precise control of the output temperature of the PTC heater, improving the heating efficiency of the PTC heater, and making the real-time output temperature of the PTC heater reach the target output temperature as quickly as possible, ensuring the stability of the real-time output temperature and meeting the heating requirements; for example, if the output temperature difference is greater than the preset maximum output temperature difference threshold, then according to the correspondence between the coolant flow and the working parameter under different output temperature differences stored in advance, the output value of the working parameter is obtained to adjust the rotation speed of the water pump according to the output value, and when the rotation speed of the water pump is adjusted according to the output value, the heating efficiency of the PTC heater reaches the highest; further, in order to make the real-time output temperature of the PTC heater reach the target output temperature as quickly as possible, while adjusting the rotation speed of the water pump, the heating power of the PTC heater can also be dynamically adjusted according to the output temperature difference to improve the heating efficiency of the PTC heater.

[0054] In some embodiments, the computing unit 702 is further configured to: A target coolant flow rate of the PTC heater is determined, where the target coolant flow rate is an average of multiple coolant flow rates within a preset statistical period.

[0055] In this embodiment, in order to accurately adjust the output temperature of the PTC heater, the speed of the water pump can be dynamically adjusted according to the target coolant flow rate; wherein, the coolant flow rate can be adjusted by adjusting the speed of the water pump, and the output temperature of the PTC heater can be adjusted by adjusting the coolant flow rate; the target coolant flow rate is the average of multiple coolant flow rates within a preset statistical period; the statistical period can be set according to actual applications, wherein the statistical period is greater than the preset time length, the statistical period is an integer multiple of the preset time length, and the statistical period can be set to 1 second.

[0056] In some embodiments, the computing unit 702 is further configured to: Determine whether the coolant flow rate is within a preset flow rate range; if not within the preset flow rate range, output corresponding flow abnormality prompt information.

[0057] In this embodiment, it is determined whether the coolant flow rate is within a preset flow rate range; the preset flow rate range can be set according to actual applications; if within the preset flow rate range, the rotation speed of the water pump is dynamically adjusted according to the coolant flow rate; specifically, the rotation speed of the water pump can be dynamically adjusted according to the set output temperature and the coolant flow rate; wherein, the coolant flow rate can be adjusted by adjusting the rotation speed of the water pump, and the output temperature of the PTC heater can be adjusted by adjusting the coolant flow rate, thereby achieving precise control of the output temperature of the PTC heater to meet heating requirements.

[0058] If it is not within the preset flow range, the corresponding flow abnormality prompt information is output, and the flow abnormality prompt information may be "coolant flow abnormality" or the like; specifically, the flow abnormality prompt information is displayed on a designated interface to prompt the user.

[0059] In some embodiments, after executing the step of determining whether the coolant flow rate is within a preset flow rate range, the calculation unit 702 is further configured to: If it is not within the preset flow range, determine whether the coolant flow is greater than the preset flow threshold; if so, output a first abnormal prompt message; if not, output a second abnormal prompt message and / or control the PTC heater to stop heating.

[0060] In this embodiment, if the coolant flow rate is not within the preset flow rate range, it is determined whether the coolant flow rate is greater than a preset flow rate threshold; the preset flow rate threshold is greater than or equal to the maximum value in the preset flow rate range, and the preset flow rate threshold can be set according to actual applications; when the coolant flow rate is greater than the preset flow rate threshold, the coolant pressure in the circulation pipeline is high, which can easily cause damage to the device. At this time, a first abnormal prompt message is output to prompt the user, and the user can reduce the speed of the water pump or turn off the PTC heater according to the first abnormal prompt message; the first abnormal prompt message can be "the pipeline pressure is high, please reduce or turn off the PTC heater, etc."

[0061] When the coolant flow rate is not within the preset flow rate range and is not greater than the preset flow rate threshold, it is determined that the PTC heater is in a dry-burning state. In order to prevent device damage, it is necessary to output a second abnormal prompt message and / or control the PTC heater to stop heating; wherein, the second abnormal prompt message is "PTC heater is dry-burning, please turn off the PTC heater or add coolant".

[0062] In some embodiments, after executing the step of calculating and obtaining the corresponding coolant flow rate, the calculation unit 702 is further used to: Obtain a theoretical coolant flow rate according to the operating parameters and characteristic data of the water pump; determine whether the difference between the coolant flow rate and the theoretical coolant flow rate is within a preset difference range; if not within the preset difference range, output a third abnormal prompt message.

[0063] In this embodiment, a theoretical coolant flow rate is obtained based on the operating parameters and characteristic data of the water pump; it is determined whether the difference between the coolant flow rate and the theoretical coolant flow rate is within a preset difference range; if within the preset difference range, subsequent operations are performed, for example, dynamically adjusting the rotation speed of the water pump based on the coolant flow rate, or obtaining a coolant flow rate compensation value based on the difference, and dynamically adjusting the rotation speed of the water pump based on the coolant flow rate compensation value and the coolant flow rate.

[0064] If it is not within the preset difference range, it means that the coolant in the circulation pipeline is insufficient, and a third abnormal prompt message is output to prompt the user. The third abnormal prompt message may be "Insufficient coolant, please refill" or the like.

[0065] In some embodiments, before executing the step of inputting the performance parameter of the coolant, the heating power and the inlet and outlet temperature difference into the preset flow calculation formula, the calculation unit 702 is further used to: The performance parameter and / or the heating power is / are converted into units according to a target measurement unit.

[0066] In this embodiment, before the performance parameters of the coolant, the heating power and the inlet and outlet temperature difference are input into the preset flow calculation formula, it is necessary to convert the performance parameters and / or the heating power according to the target measurement unit; the target measurement unit can be the measurement unit of the coolant flow, and the target measurement unit can be set to m 3 / h; For example, the heating power of the PTC heater is 6.65KW. At this time, the measurement unit of the heating power does not match the target measurement unit. Therefore, it is necessary to calculate the heating power according to the target measurement unit m 3 / h to convert its unit, the specific conversion formula is: Q = 6.65×3600KJ / h = 23940KJ / h; where Q is the heating power.

[0067] In some embodiments, when the acquisition unit 701 performs the step of regularly acquiring the inlet and outlet temperature difference of the PTC heater, it is specifically used to: The first coolant temperature collected by the first temperature sensor and the second coolant temperature collected by the second temperature sensor are obtained at regular intervals; wherein the first temperature sensor is arranged at the water inlet of the PTC heater, and the second temperature sensor is arranged at the water outlet of the PTC heater; and the difference between the first coolant temperature and the second coolant temperature is taken as the inlet and outlet temperature difference.

[0068] In this embodiment, the first temperature sensor obtains the coolant temperature at the water inlet of the PTC heater and provides it to the controller; the second temperature sensor obtains the coolant temperature at the water outlet of the PTC heater and provides it to the controller; the controller can calculate the inlet and outlet temperature difference based on the first coolant temperature and the second coolant temperature.

[0069] In summary, the embodiment of the present invention can calculate and obtain the corresponding coolant flow rate by inputting the performance parameters of the coolant, the heating power and the inlet and outlet temperature difference into a preset flow calculation formula, thereby realizing low-cost calculation and acquisition of the coolant flow rate; further, compared with the use of a dedicated flow meter to obtain the coolant flow rate in the prior art, the embodiment of the present invention can reduce the coolant flow meter assembly and reduce the coolant flow rate calculation cost; the embodiment of the present invention can also obtain the output value of the working parameter according to the correspondence between the pre-stored coolant flow rate and the working parameter under different output temperature differences to control the output temperature of the PTC heater according to the output value, thereby realizing precise control of the output temperature of the PTC heater, improving the heating efficiency of the PTC heater, and making the real-time output temperature of the PTC heater reach the target output temperature as quickly as possible, ensuring the stability of the real-time output temperature and meeting the heating requirements.

[0070] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A flow control method based on a PTC heater, characterized in that: The method is applied to a controller of a vehicle-mounted heating device, the vehicle-mounted heating device includes a PTC heater, the controller is communicatively connected with the PTC heater, and the method includes: Regularly obtain the inlet and outlet temperature difference and heating power of the PTC heater; Input the performance parameters of the coolant, the heating power and the inlet and outlet temperature difference into a preset flow calculation formula to calculate and obtain the corresponding coolant flow; According to the pre-stored correspondence between the coolant flow rate and the working parameter at different output temperature differences, the output value of the working parameter is obtained to control the output temperature of the PTC heater according to the output value.

2. The flow control method based on the PTC heater according to claim 1, characterized in that: After the calculation to obtain the corresponding coolant flow rate, the method further includes: The target coolant flow rate of the PTC heater is determined, and a plurality of coolant flow rates within a preset statistical period are acquired and an average is calculated to obtain the target coolant flow rate.

3. The flow control method based on a PTC heater according to claim 1, characterized in that: After the calculation to obtain the corresponding coolant flow rate, the method further includes: Determining whether the coolant flow rate is within a preset flow rate range; If it is not within the preset flow rate range, the corresponding flow abnormality prompt information is output.

4. The flow control method based on a PTC heater according to claim 3, characterized in that: After determining whether the coolant flow rate is within a preset flow rate range, the method further includes: If it is not within the preset flow range, determining whether the coolant flow is greater than a preset flow threshold; If yes, output the first abnormal prompt information; If not, a second abnormal prompt message is output and / or the PTC heater is controlled to stop heating.

5. The flow control method based on PTC heater according to claim 1, characterized in that: After the calculation to obtain the corresponding coolant flow rate, the method further includes: Obtain theoretical coolant flow rate based on the operating parameters and characteristic data of the water pump; Determining whether a difference between the coolant flow rate and the theoretical coolant flow rate is within a preset difference range; If it is not within the preset difference range, a third abnormal prompt information is output.

6. The flow control method based on PTC heater according to claim 1, characterized in that: Before inputting the performance parameters of the coolant, the heating power and the inlet and outlet temperature difference into the preset flow calculation formula, the method further includes: The performance parameter and / or the heating power is / are converted into units according to a target measurement unit.

7. The flow control method based on a PTC heater according to claim 1, characterized in that: The step of regularly obtaining the inlet and outlet temperature difference of the PTC heater includes: Regularly acquiring a first coolant temperature collected by a first temperature sensor and a second coolant temperature collected by a second temperature sensor; wherein the first temperature sensor is arranged at a water inlet of the PTC heater, and the second temperature sensor is arranged at a water outlet of the PTC heater; The difference between the first coolant temperature and the second coolant temperature is used as the inlet and outlet temperature difference.

8. A flow control device based on a PTC heater, characterized in that: The device is configured in a controller of a vehicle-mounted heating device, the vehicle-mounted heating device includes a PTC heater, the controller is communicatively connected with the PTC heater, and the device includes: An acquisition unit, used for regularly acquiring the inlet and outlet temperature difference and heating power of the PTC heater; A calculation unit, used for inputting the performance parameters of the coolant, the heating power and the inlet and outlet temperature difference into a preset flow calculation formula to calculate and obtain the corresponding coolant flow; The control unit is used to obtain the output value of the working parameter according to the pre-stored correspondence between the coolant flow rate and the working parameter under different output temperature differences so as to control the output temperature of the PTC heater according to the output value.

9. The flow control device based on a PTC heater according to claim 8, characterized in that: The computing unit is also used for: The target coolant flow rate of the PTC heater is determined, and a plurality of coolant flow rates within a preset statistical period are acquired and an average is calculated to obtain the target coolant flow rate.

10. The flow control device based on a PTC heater according to claim 8, characterized in that: The computing unit is also used for: Determining whether the coolant flow rate is within a preset flow rate range; If it is not within the preset flow rate range, the corresponding flow abnormality prompt information is output.

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