Heat management device with integrated compressor heater and control board and method of controlling the same

Abstract

The application discloses a compressor heater and control panel integrated heat management device and a control method thereof, which comprises a thick film heater, a PCBA control panel and a compressor integrated together; the PCBA control panel simultaneously controls the thick film heater and the compressor to work; at least a capacitance liquid level detection circuit for detecting whether the cooling liquid exists in the thick film heater, a heating circuit for heating the thick film heater and a low-voltage direct-current temperature measurement circuit for directly measuring the temperature of the thick film heater are printed on the thick film heater plate of the thick film heater; the low-voltage circuit of the PCBA control panel is electrically connected with the resistance positive electrode pin and the resistance negative electrode pin of the low-voltage direct-current temperature measurement circuit. The application realizes the heat management of the three-electric system through the integrated design, improves the low-temperature starting reliability and the high-temperature operation safety, and simultaneously simplifies the system structure and improves the heat response efficiency.

Description

Technical Field

[0001] This invention relates to the field of thermal management technology for new energy vehicles, and in particular to a thermal management device and control strategy that integrates a compressor heater and a control board. Background Technology

[0002] The performance of batteries, motors, and electronic control systems in new energy vehicles is prone to degradation in low-temperature environments, while they may overheat in high-temperature environments. Therefore, efficient thermal management is essential to ensure vehicle starting performance and system operating efficiency. Traditional thick-film heaters use NTC devices soldered to the back of the heating plate for temperature monitoring. However, this method is unsuitable for immersion heating solutions and makes it difficult to ensure the NTC is sealed in the coolant. For higher-power heaters, heating plate temperatures can reach 250°C, at which temperature solder joints can detach, leading to NTC detachment and temperature measurement failure. Furthermore, to prevent the thick film heating plate from dry burning, existing thick film heaters typically calculate the resistance of the heating plate based on the voltage and current across the heating resistor used for high-voltage heating, collected by the control board, and then deduce the temperature of the heating plate. However, in this method, the voltage value collected by the control board is affected by the duty cycle and the calculation formula and is not the actual voltage value across the heating resistor, resulting in an inaccurate temperature value. In addition, this temperature measurement method requires high voltage to be turned on before the temperature can be detected. However, if the original temperature of the heating plate is very high, applying high voltage will reheat the heating plate, which can easily cause the heating plate to overheat and be damaged, ultimately damaging the integrated equipment.

[0003] In the existing technology, there are very few thermal management devices that integrate heaters, compressors and control boards. This is because the heaters themselves operate at relatively high temperatures, while the compressors require a low-temperature environment. If the temperature control inside the heater is abnormal, it can easily cause damage to the compressor. Therefore, in order to achieve the integration of the three components, higher requirements are placed on the accuracy of temperature detection. How to achieve safer integrated thermal management is a technical problem that this application urgently needs to solve. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the technical problem this invention aims to solve is to provide a thermal management device and control method that integrates a compressor heater and a control board. This integrated design enables thermal management of the three-electric system, improving low-temperature start-up reliability and high-temperature operation safety, while also simplifying the system structure and improving thermal response efficiency.

[0005] The technical solution adopted by the present invention to solve the aforementioned technical problem is as follows: A thermal management device integrating a compressor heater and a control board includes an integrated thick film heater, a PCBA control board, and a compressor; the PCBA control board simultaneously controls the operation of the thick film heater and the compressor. The thick film heater has at least a capacitor level detection circuit for real-time detection of the presence of coolant inside the heater, a heating circuit for heating the thick film heater, and a low-voltage DC temperature measurement circuit for directly measuring the temperature of the thick film heater. The low-voltage circuit of the PCBA control board is electrically connected to the positive and negative resistor pins of the low-voltage DC temperature measurement circuit.

[0006] Furthermore: The thick film heater is a thick film heating plate that heats liquid by immersing it in coolant. Both sides of the thick film heating plate have flow channel structures. The liquid to be heated enters through the coolant inlet of the upper shell of the thick film heater, flows through the flow channel structure to convect and exchange heat on both sides of the thick film heating plate, and flows out through the coolant outlet of the upper shell.

[0007] Furthermore, the thick film heating plate has a total of six welding pins, namely capacitor positive pin 121, capacitor negative pin 122, heating positive pin 123, heating negative pin 124, resistor positive pin 125, and resistor negative pin 126. The capacitor positive and negative pins are all in an open circuit state, while the heating positive and negative pins and resistor positive and negative pins are all in a conductive state.

[0008] Furthermore: AC current is applied to the two soldered pins of the capacitor level detection circuit for sampling and capacitance value calculation; high voltage DC current is applied to the heating circuit to realize the heating function, and the applied voltage value is controlled by the IGBT module in the PCBA control board.

[0009] Furthermore: A fixed current chip and a low-voltage measurement circuit are set on the low-voltage side of the PCBA control board. The low-voltage DC temperature measurement circuit is a low-resistance circuit printed with thick film. The positive / negative pins of the resistor are connected in series with the fixed current chip, and the voltage in the low-voltage DC temperature measurement circuit is detected in real time by the low-voltage voltage measurement circuit. The fixed current chip keeps the current in the low-voltage DC temperature measurement circuit constant. According to the resistance value R=U / I, the resistance value of the low-voltage DC temperature measurement circuit is obtained by using the real-time voltage collected by the low-voltage voltage measurement circuit. Then, the temperature of the thick film heating plate is obtained according to the resistance-temperature characteristic curve.

[0010] Furthermore: The PCBA control board receives instructions from the vehicle's thermal management system. When a heating instruction is received, the thick film heater is turned on to heat the coolant to the specified temperature. When a cooling instruction is received, the compressor is turned on to compress the refrigerant entering through the coolant inlet to the set pressure and then discharge it through the coolant outlet.

[0011] This invention also protects a control method for a thermal management device integrating a compressor heater and a control board. The heater adopts a thick-film heating structure, with high-voltage heating resistors printed on the surface of the thick-film heating plate to form a heating circuit for heating the coolant. The heating circuit is arranged around the edge of the thick-film heating plate corresponding to the flow channel structure. Simultaneously, two parallel capacitor detection circuits are arranged on the thick-film heating plate outside the heating circuit, simulating electrode plates, for real-time detection of the presence of coolant inside the heater. In addition, a low-voltage DC temperature measurement circuit is also arranged on the heating plate and continuously connected to the low-voltage circuit of the PCBA control board for real-time monitoring of the temperature of the thick-film heating plate. After the system is powered on, the thermal management device first determines whether there is coolant inside the heater through the capacitor detection circuit. If no liquid is detected, the high-voltage heating output is immediately shut off, and a protection strategy is triggered to prevent the thick-film heater from being damaged by dry burning. When the coolant is detected to be present and flowing, the PCBA control board further obtains the real-time temperature of the thick-film heating plate through the low-voltage temperature detection circuit and determines whether it is within the preset safety range. If the temperature is normal, the high-voltage heating resistor is allowed to operate. If the heating plate temperature is detected to be too high, the high-voltage heating output is immediately shut off or limited, and the low-voltage temperature detection circuit is continuously used to monitor the temperature of the thick-film heating plate. After the temperature returns to the safe range, the board decides whether to resume heating based on the operating conditions. Because the low-voltage temperature detection circuit has low power, even when the thick film heating plate is at a high temperature, it will not generate additional thermal shock due to the traditional high-voltage temperature measurement method, thereby avoiding damage to the heating plate and the three-in-one integrated device and improving the safety and reliability of the system operation. The PCBA control board receives instructions from the vehicle's thermal management system. When it receives a heating instruction, it turns on the thick film heater to heat the coolant to the specified temperature. When it receives a cooling instruction, it turns on the compressor to compress the refrigerant entering through the coolant inlet to the set pressure and then discharge it through the coolant outlet.

[0012] The present invention also provides a new energy vehicle, wherein the thermal management device described above is used in the new energy vehicle, and the thermal management device is electrically connected to the vehicle thermal management system of the new energy vehicle.

[0013] Compared with existing technologies, the beneficial effects of this invention are: 1. Control Innovation: This invention features a separate low-voltage DC temperature sensing circuit printed on the surface of the thick-film heating plate for real-time online temperature detection. This circuit connects to the low-voltage circuit of the PCBA control board and is normally closed. Due to the low voltage applied to this circuit, the heat generated is also very low. Even when the heating plate is at a high temperature, the heat generated by this resistor is minimal, preventing reheating of the heating plate. This achieves more precise control of the thick-film heating plate and effectively solves the problem of dry burning. Compared to traditional TCR temperature measurement solutions, this invention provides more accurate temperature monitoring of the thick-film heating plate and avoids failure due to excessively high heating plate temperatures, fundamentally solving the problem of heater overheating.

[0014] 2. Small size and high integration: By integrating the compressor, immersion thick film heater and control board, the overall size and layout complexity of the system are significantly reduced, making it easy to install and maintain in the compact space of new energy vehicles.

[0015] 3. Dual heating and cooling functions: This equipment can not only quickly heat the battery in low-temperature environments to improve low-temperature start-up reliability, but also assist in cooling in high-temperature environments to achieve rapid cooling of the three-electric system, thereby improving high-temperature operation safety and overall vehicle energy efficiency. Attached Figure Description

[0016] Figure 1 : Exploded view of a thermal management device integrating a compressor heater and a control board according to the present invention.

[0017] Figure 2 : A bottom view of the thick film heater of the present invention.

[0018] Figure 3 for Figure 2 A schematic diagram of the cross-sectional structure along direction A.

[0019] Figure 4 This is a schematic diagram of the thick film heating plate 12 inside the thick film heater in this invention.

[0020] Figure 5 This is a flowchart illustrating the control method of the present invention.

[0021] In the diagram, there are: 1. Thick film heater; 2. PCBA control board; 3. Compressor. Lower housing 11, thick film heating plate 12, upper housing 13, upper flow channel 14, lower flow channel 16, coolant inlet 21, coolant outlet 22; Coolant inlet 131, coolant outlet 132; coolant inlet 31, coolant outlet 32; Capacitor positive pin 121, capacitor negative pin 122, heating positive pin 123, heating negative pin 124, resistor positive pin 125, resistor negative pin 126. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1 like Figure 1 The diagram illustrates a thermal management device integrating a compressor heater and a control board according to the present invention. From left to right, it comprises: a thick-film heater 1, a PCBA control board 2, and a compressor 3. The thick-film heater consists of a lower housing 11, a thick-film heating plate 12, and an upper housing 13. The PCBA control board 2 can simultaneously control the operation of both the thick-film heater and the compressor. The three components—thick-film heater 1, PCBA control board 2, and compressor 3—are integrated together. The PCBA control board 2 is placed inside the upper housing 13 of the thick-film heater. The thick-film heater does not have a cover. The housing on the compressor side mates with the side of the upper housing where the PCBA control board 2 is installed, sealing the upper housing. A coolant inlet 31 is located on the side of the compressor closest to the PCBA control board 2, and a coolant outlet 32 ​​is located on the side of the compressor furthest from the PCBA control board 2.

[0024] like Figure 2 , Figure 3 The thick-film heater shown is a thick-film heating plate 12 that heats liquid by immersion in coolant. The thick-film heating plate has flow channel structures on both its upper and lower sides, namely an upper flow channel 14 and a lower flow channel 16. The liquid to be heated enters through the coolant inlet 131 on the upper shell, flows through the flow channel structure to both sides of the thick-film heating plate for convective heat exchange, and exits through the coolant outlet 132 on the upper shell. A lower flow channel 16 is provided between the lower shell 11 and the thick-film heating plate 12, and an upper flow channel 14 is provided between the lower surface of the upper shell and the thick-film heating plate. The thick-film heating plate covers the upper end of the lower shell, and the metal substrate of the thick-film heating plate contacts the upper end of the lower shell. Bosses are provided on both sides of the upper shell, which can press against the metal substrate of the thick-film heating plate. Simultaneously, the inner wall surface of the upper shell contacts the outer wall surface of the lower shell 3. Figure 3 As shown, the upper shell 11, the metal substrate, and the lower shell can be effectively connected and conductive after installation and welding, forming a conductive whole that is directly grounded.

[0025] like Figure 4As shown, the thick film heating plate 12 has three types of printed circuits: a capacitor level detection circuit, a heating circuit, and a low-voltage DC temperature measurement circuit; a total of six soldering pins, namely capacitor positive pin 121, capacitor negative pin 122, heating positive pin 123, heating negative pin 124, resistor positive pin 125, and resistor negative pin 126. All six pins pass through the upper shell and are electrically connected to the PCBA control board; the capacitor positive and negative pins are in an open circuit state, while the heating positive and negative pins and the resistor positive and negative pins are in a conductive state.

[0026] The two soldered pins of the capacitor level detection circuit need to be supplied with alternating current for sampling and capacitance calculation. Both the positive and negative pins of the capacitor are connected to the low-voltage side of the PCBA board.

[0027] The heating circuit requires a high-voltage direct current to achieve its heating function, and the applied voltage is controlled by the IGBT module in the PCBA control board. This part is existing technology. This circuit requires a high voltage, resulting in a relatively fast heating speed, approximately on the order of milliseconds. Existing technology directly uses the resistance value calculated from this high-voltage side to derive the heating plate temperature. While measuring the temperature, the heating plate is heated simultaneously. If the heating plate itself is very hot, it can easily be damaged. Therefore, the measured temperature is inaccurate and has a lag.

[0028] The low-voltage DC temperature sensing circuit requires the PCBA control board to directly supply low-voltage DC voltage to its positive and negative terminals. It directly and in real-time collects current values ​​under different operating conditions to calculate the resistance value of the temperature sensing circuit. Finally, the temperature of the heating plate is deduced based on the resistance-temperature characteristic curve of the temperature sensing circuit. This circuit is directly connected to the low-voltage circuit of the PCBA control board, which is supplied with low-voltage DC voltage from the automotive power supply. The circuit is normally closed, and because the voltage applied to this circuit is low, the heat generated is also very low. Compressors are prone to damage at high temperatures. If the automotive thermal management system equipment or pipelines malfunction, leading to dry burning of the heater due to lack of water or still water (high-precision temperature detection board temperature of the low-voltage DC temperature sensing circuit), the heating plate temperature will rise sharply, adversely affecting the entire integrated thermal management equipment and even damaging it. Therefore, more accurate detection of the heater temperature is particularly important.

[0029] As an example, a fixed current chip and a low-voltage measurement circuit are set on the low-voltage side of the PCBA control board. The resistance value in the low-voltage DC temperature sensing circuit is small (approximately a few ohms, preferably 0-5Ω, not 0). The positive / negative leads of the resistor are connected in series with the fixed current chip, and the voltage in the low-voltage DC temperature sensing circuit is detected in real time by the low-voltage voltage measurement circuit. The fixed current chip keeps the current in the low-voltage DC temperature sensing circuit constant. According to the resistance value R=U / I, the resistance value of the low-voltage DC temperature sensing circuit is obtained in real time using the real-time voltage collected by the low-voltage voltage measurement circuit. Then, the temperature of the thick film heating plate is obtained according to the resistance-temperature characteristic curve. The resistance-temperature characteristic curve is related to the material properties of the printed resistor, and the curve is known when the material is selected.

[0030] Example 2 The control method of the thermal management device integrating the compressor heater and control board in this embodiment is as follows: Figure 5 As shown, the heater employs a thick-film heating structure. High-voltage heating resistors (heating circuits) are printed on the surface of the thick-film heating plate to heat the coolant. These heating circuits are positioned around the edge of the thick-film heating plate corresponding to the flow channel structure. Simultaneously, two parallel capacitor detection circuits, simulating electrode plates, are installed on the thick-film heating plate outside the heating circuits to detect the presence of coolant inside the heater in real time. Furthermore, a low-voltage DC temperature measurement circuit is installed on the heating plate and continuously connected to the low-voltage circuit of the PCBA control board for real-time monitoring of the thick-film heating plate temperature. After the system is powered on, the thermal management device first determines the presence of coolant inside the heater through the capacitor detection circuits. If no liquid is detected, the high-voltage heating output is immediately shut off, and a protection strategy is triggered (heating is prohibited, high-voltage heating output is shut off, an alarm is triggered, and fault information is recorded) to prevent the thick-film heater from dry-burning and being damaged.

[0031] When the coolant is detected to be present and flowing, the PCBA control board further obtains the real-time temperature of the thick-film heater plate through the low-pressure temperature detection circuit and determines whether it is within the preset safety range. If the temperature is normal, the high-voltage heating resistor is allowed to operate. If the heater plate temperature is detected to be too high, the high-voltage heating output is immediately shut off or limited, and the low-pressure temperature detection circuit continues to monitor the temperature of the thick-film heater plate. Once the temperature returns to the safe range, a decision is made on whether to resume heating based on operating conditions. Because the low-pressure temperature detection circuit has low power, even when the thick-film heater plate is at a high temperature, it will not generate additional thermal shock due to traditional high-pressure temperature measurement methods, thus avoiding damage to the heater plate and the three-in-one integrated device, improving the safety and reliability of system operation. The PCBA control board receives instructions from the vehicle's thermal management system. When a heating instruction is received, the thick-film heater is turned on to heat the coolant to the specified temperature; when a cooling instruction is received, the compressor is turned on to compress the refrigerant entering through the coolant inlet to the set pressure and then discharge it through the coolant outlet.

[0032] The compressor can be any existing type of compressor, such as a scroll compressor or a screw compressor.

[0033] The invention employs a low-voltage temperature detection circuit, which is online in real time and can detect the temperature of the thick film heating plate in real time. Even if the heating plate is in a high-temperature state, the temperature detection will not cause additional thermal shock or damage to the heating plate, further ensuring its safety and reliability.

[0034] This invention integrates capacitor level detection and low-voltage DC temperature measurement, enabling real-time monitoring of the coolant level and temperature of the thick-film heater. It intelligently adjusts the operating status of the heater and compressor based on level and temperature changes, achieving precise, safe, and efficient thermal management. Furthermore, the integrated design of the compressor, immersion thick-film heater, and PCBA control board significantly reduces the overall system size, simplifies the layout, and facilitates installation and maintenance in the compact spaces of new energy vehicles. In addition, this device combines heating and cooling functions, enabling rapid heating of new energy vehicle batteries in low-temperature environments, improving the vehicle's low-temperature start-up performance and operational reliability. It can also achieve efficient cooling in high-temperature environments. The low-voltage DC temperature measurement circuit can provide real-time and accurate temperature feedback during operation, ensuring the operational safety of thermal management equipment. This, in turn, ensures the safe operation of the three-electric system (mainly the battery, motor, and electronic control) and improves the overall vehicle energy efficiency. The immersion thick film heater is in direct contact with the coolant, resulting in high heat transfer efficiency and fast response. Combined with intelligent control strategies, it achieves efficient energy utilization. Overall, it overcomes the problems of separate control, slow response, large system size, and single thermal management function in existing technologies, providing a small-volume, high-efficiency, intelligent, and comprehensive thermal management solution for new energy vehicles that combines heating and cooling.

[0035] Any aspects not covered in this invention are applicable to existing technologies.

Claims

1. A thermal management device integrating a compressor heater and a control board, characterized in that, It includes an integrated thick film heater, PCBA control board, and compressor; the PCBA control board controls the operation of both the thick film heater and the compressor. The thick film heater has at least a capacitor level detection circuit for real-time detection of the presence of coolant inside the heater, a heating circuit for heating the thick film heater, and a low-voltage DC temperature measurement circuit for directly measuring the temperature of the thick film heater. The low-voltage circuit of the PCBA control board is electrically connected to the positive and negative resistor pins of the low-voltage DC temperature measurement circuit.

2. The thermal management device according to claim 1, characterized in that: The thick film heater is a thick film heating plate that heats liquid by immersing it in coolant. Both sides of the thick film heating plate have flow channel structures. The liquid to be heated enters through the coolant inlet of the upper shell of the thick film heater, flows through the flow channel structure to convect and exchange heat on both sides of the thick film heating plate, and flows out through the coolant outlet of the upper shell.

3. The thermal management device according to claim 1, characterized in that: The thick film heating plate has a total of six welding pins, namely the positive pin of the capacitor, the negative pin of the capacitor, the positive pin of the heating electrode, the negative pin of the heating electrode, the positive pin of the resistor, and the negative pin of the resistor. The positive and negative pins of the capacitor are all in an open circuit state, while the positive and negative pins of the heating electrode and the positive and negative pins of the resistor are all in a conductive state.

4. The thermal management device according to claim 1, characterized in that: The two soldered pins of the capacitor level detection circuit are fed with AC current for sampling and capacitance value calculation; the heating circuit is fed with high voltage DC current to realize the heating function, and the applied voltage value is controlled by the IGBT module in the PCBA control board.

5. The thermal management device according to claim 1, characterized in that: A fixed current chip and a low-voltage measurement circuit are set on the low-voltage side of the PCBA control board. The low-voltage DC temperature measurement circuit is a low-resistance circuit printed with thick film. The positive and negative pins of the resistor are connected in series with the fixed current chip, and the voltage in the low-voltage DC temperature measurement circuit is detected in real time by the low-voltage voltage measurement circuit. The fixed current chip keeps the current in the low-voltage DC temperature measurement circuit constant. According to the resistance value R=U / I, the resistance value of the low-voltage DC temperature measurement circuit is obtained by using the real-time voltage collected by the low-voltage voltage measurement circuit. Then, the temperature of the thick film heating plate is obtained according to the resistance-temperature characteristic curve.

6. The thermal management device according to claim 1, characterized in that: The PCBA control board receives instructions from the vehicle's thermal management system. When it receives a heating instruction, it turns on the thick film heater to heat the coolant to the specified temperature. When it receives a cooling instruction, it turns on the compressor to compress the refrigerant entering through the coolant inlet to the set pressure and then discharge it through the coolant outlet.

7. The thermal management device according to claim 1, characterized in that: The compressor is a scroll compressor or a screw compressor.

8. A control method for a thermal management device integrating a compressor heater and a control board, characterized in that, The heater employs a thick-film heating structure, with high-voltage heating resistors printed on the surface of the thick-film heating plate to form heating circuits for heating the coolant. These heating circuits are positioned around the edges of the thick-film heating plate corresponding to the flow channel structure. Simultaneously, two parallel capacitor detection circuits, simulating electrode plates, are installed on the thick-film heating plate outside the heating circuits to detect the presence of coolant inside the heater in real time. Furthermore, a low-voltage DC temperature measurement circuit is installed on the heating plate and continuously connected to the low-voltage circuit of the PCBA control board for real-time monitoring of the thick-film heating plate temperature. Upon system power-up, the thermal management device first determines the presence of coolant inside the heater via the capacitor detection circuits. If no liquid is detected, the high-voltage heating output is immediately shut off, and a protection strategy is triggered to prevent the thick-film heater from dry-burning and being damaged. When the coolant is detected to be present and flowing, the PCBA control board further obtains the real-time temperature of the thick-film heating plate through the low-voltage temperature detection circuit and determines whether it is within the preset safety range. If the temperature is normal, the high-voltage heating resistor is allowed to operate. If the heating plate temperature is detected to be too high, the high-voltage heating output is immediately shut off or limited, and the low-voltage temperature detection circuit is continuously used to monitor the temperature of the thick-film heating plate. After the temperature returns to the safe range, the board decides whether to resume heating based on the operating conditions. Because the low-voltage temperature detection circuit has low power, even when the thick film heating plate is at a high temperature, it will not generate additional thermal shock due to the traditional high-voltage temperature measurement method, thereby avoiding damage to the heating plate and the three-in-one integrated device and improving the safety and reliability of the system operation. The PCBA control board receives instructions from the vehicle's thermal management system. When it receives a heating instruction, it turns on the thick film heater to heat the coolant to the specified temperature. When it receives a cooling instruction, it turns on the compressor to compress the refrigerant entering through the coolant inlet to the set pressure and then discharge it through the coolant outlet.

9. A new energy vehicle, characterized in that, The new energy vehicle uses the thermal management device according to any one of claims 1-7, and the thermal management device is electrically connected to the vehicle thermal management system of the new energy vehicle.

Images