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CN-116845427-B - Power battery heating system and water temperature control method for heating power battery

CN116845427BCN 116845427 BCN116845427 BCN 116845427BCN-116845427-B

Abstract

The invention discloses a power battery heating system and a water temperature control method for heating a power battery, which utilize a three-way proportional valve and a first three-way valve to introduce an engine waste heat recovery waterway into the power battery for heating, and adjust the cooling water quantity of the engine entering a battery heat exchanger by adjusting the opening of a first outlet and the opening of a second outlet of the three-way proportional valve, so that the real-time adjustment of the expected water inlet temperature entering the battery heat exchanger is realized, the heating water inlet temperature of the power battery is controlled at the expected water inlet temperature, and the influence of the heating of the power battery on the service life of the power battery is avoided.

Inventors

  • ZHENG YONGWEI
  • ZHENG JIA

Assignees

  • 深蓝汽车科技有限公司

Dates

Publication Date
20260505
Application Date
20230703

Claims (7)

  1. 1. The power battery heating system comprises a controller, a PTC heating power battery waterway, a first temperature sensor (1) for detecting the actual water inlet temperature of a battery heat exchanger and a second temperature sensor (2) for detecting the actual water inlet temperature of the power battery; the PTC heating power battery is characterized by further comprising a three-way proportional valve (3), a first three-way valve (4), an engine waste heat recovery waterway and a third temperature sensor (5) which is used for detecting the water temperature of the engine and is connected with the controller, wherein an inlet of the three-way proportional valve (3) is connected with an outlet of the PTC heating power battery waterway, a first outlet of the three-way proportional valve (3) is connected with a first inlet of the first three-way valve (4), an outlet of the first three-way valve (4) is connected with an inlet of the PTC heating power battery waterway, a second outlet of the three-way proportional valve (3) is connected with an inlet of the engine waste heat recovery waterway, an outlet of the engine waste heat recovery waterway is connected with a second inlet of the first three-way valve (4), the controller is connected with the three-way proportional valve (3), and the first outlet opening and the second outlet opening of the three-way proportional valve (3) are controlled according to the water temperature of the engine, the actual water inlet temperature of the battery heat exchanger and the actual water inlet temperature of the power battery, wherein the PTC heating power battery comprises a PTC heater (13), a heat exchanger (14) and a water pump (15), the outlet of the battery water storage bottle (17) is connected with the first inlet of the fifth three-way valve (18), the outlet of the fifth three-way valve (18) is connected with the inlet of the third water pump (16), the outlet of the third water pump (16) is connected with the first inlet of the battery heat exchanger (14), the first outlet of the battery heat exchanger (14) is connected with the pipeline inlet of the power battery (19), the pipeline outlet of the power battery (19) is connected with the second inlet of the fifth three-way valve (18), the inlet of the second water pump (15) is used as the inlet of a PTC heating power battery waterway, the outlet of the second water pump (15) is connected with the inlet of the PTC heater (13), the outlet of the PTC heater (13) is connected with the second inlet of the battery heat exchanger (14), the second outlet of the battery heat exchanger (14) is used as the outlet of the PTC heating power battery waterway, the controller is connected with the second water pump (15) and the third water pump (16), the pipeline outlet of the power battery (19) is controlled to be connected with the second water pump (15), the third water pump (16) is controlled to the third water pump (16) is connected with the outlet of the PTC heater (13) which is connected with the PTC heater (13) by the PTC heater (13), the second temperature sensor (2) is mounted on a water pipe connecting a pipe inlet in the power battery (19) with a first outlet of the battery heat exchanger (14).
  2. 2. The power battery heating system according to claim 1, wherein the engine waste heat recovery waterway comprises a second three-way valve (6), a third three-way valve (7), a first water pump (8), an engine water jacket (9) and a fourth three-way valve (10), wherein a first inlet of the second three-way valve (6) is used as an inlet of the engine waste heat recovery waterway, a second inlet of the second three-way valve (6) is connected with an outlet of an engine water storage bottle (11), an outlet of the second three-way valve (6) is connected with a first inlet of the third three-way valve (7), a second inlet of the third three-way valve (7) is connected with an outlet of an engine radiator (12), an outlet of the third three-way valve (7) is connected with an inlet of a first water pump (8), an outlet of the first water pump (8) is connected with an inlet of the engine water jacket (9), an outlet of the engine water jacket (9) is connected with an inlet of the fourth three-way valve (10), a first outlet of the fourth three-way valve (10) is connected with an inlet of the engine radiator (12), and a second outlet of the fourth three-way valve (10) is used as an outlet of the engine waste heat controller, and the third water pump (8) is connected with the third water pump (8) and the third water pump (8) is connected with the outlet of the third water pump (9) to the water pump.
  3. 3. The power battery heating system according to claim 2, wherein a thermostat (20) is mounted on a water pipe connecting the first outlet of the fourth three-way valve (10) with the inlet of the engine radiator (12).
  4. 4. A power battery heating water temperature control method applied to the power battery heating system according to any one of claims 1 to 3, the method being performed by a controller, comprising: S1, judging whether a power battery has a heating requirement, if so, executing S2, otherwise, continuing executing S1; S2, judging whether the engine is in a running state, if so, executing S3, otherwise, executing S4; s3, judging whether the water temperature of the engine is greater than or equal to a preset first temperature threshold Tx, if so, executing S5, otherwise, executing S4; S4, controlling the opening of a first outlet of the three-way proportional valve (3) to be 100% and the opening of a second outlet to be 0, controlling the PTC heater (13) to work, and then returning to execute S1; S5, inquiring a preset water inlet temperature table according to the temperature of the power battery to obtain the current expected water inlet temperature Ta for heating the power battery, and then executing S6, wherein the preset water inlet temperature table is a corresponding relation table of the temperature of the power battery and the expected water inlet temperature for heating the power battery, which is obtained through calibration; S6, determining a current expected water inlet temperature T t of the battery heat exchanger according to a current expected water inlet temperature Ta of the power battery, an actual water inlet temperature Tb of the power battery and an expected water inlet temperature T t-1 of a previous battery heat exchanger, and then executing S7, wherein the method for determining the expected water inlet temperature T t of the current battery heat exchanger is that if Ta is larger than Tb+Ty, T t =T t-1 +Tz is caused, if Tb-Ty is smaller than or equal to Ta and smaller than Tb+Ty, T t =T t-1 is caused, if Ta is smaller than Tb-Ty, T t =T t-1 -Tz is caused, ty represents a preset second temperature threshold, tz represents a preset third temperature threshold, and an expected water inlet temperature initial value T 0 of the battery heat exchanger is equal to a preset fourth temperature threshold Tv; S7, according to the expected water inlet temperature T t of the current battery heat exchanger and the actual water inlet temperature Tc of the battery heat exchanger, regulating the first outlet opening and the second outlet opening of the three-way proportional valve (3), and then returning to the S1, wherein the method for regulating the first outlet opening and the second outlet opening of the three-way proportional valve (3) is that if T t is larger than Tc+Ty, the first outlet opening and the second outlet opening of the three-way proportional valve (3) are controlled to be reduced by m, if Tc-Ty is smaller than or equal to T t and smaller than Tc+Ty, the first outlet opening and the second outlet opening of the three-way proportional valve (3) are controlled to be unchanged, if T t is smaller than Tc-Ty, the first outlet opening and the second outlet opening of the three-way proportional valve (3) are controlled to be reduced by m, m represents a preset opening threshold value, and the first outlet opening initial value of the three-way proportional valve (3) is controlled to be 100%, and the second outlet opening initial value is controlled to be 0.
  5. 5. The method for controlling the water temperature heated by a power battery according to claim 4, wherein the preset first temperature threshold Tx=60 ℃, the preset second temperature threshold Ty=2 ℃, the preset third temperature threshold tz=2 ℃, the preset fourth temperature threshold tv=50 ℃ and the preset opening threshold m=1%.
  6. 6. The method of claim 4 or 5, wherein if the power supply of the whole vehicle is in an ON state, the running heating function is turned ON, the temperature of the power battery is less than a fifth preset temperature threshold Tu, and the SOC of the power battery is greater than a preset SOC threshold, the power battery is heated.
  7. 7. The method of claim 6, wherein the preset fifth temperature threshold Tu=0 ℃ and the preset SOC threshold is 10%.

Description

Power battery heating system and water temperature control method for heating power battery Technical Field The invention belongs to the field of vehicle thermal management, and particularly relates to a power battery heating system and a power battery heating water temperature control method. Background In a low temperature environment, the ionic activity of the power battery is reduced, resulting in a great reduction in discharge capacity. The vehicle evaluation mechanism tests the endurance mileage of the new energy vehicle in winter in the north, and discovers that the endurance mileage of the new energy vehicle is basically reduced by more than half, thereby seriously affecting the driving mileage of the new energy vehicle. The temperature of the power battery is increased in winter, and the ion activity in the power battery is increased, so that the discharge capacity of the power battery is increased, and the method becomes an important means for increasing the endurance mileage of the new energy vehicle in winter. CN111546945A discloses a heating device, a heating control method and an extended-range electric vehicle for a power battery, which describe that the power battery can be heated by using the waste heat of an engine. However, when the power battery is heated, the water inlet temperature of the power battery is strictly required, otherwise, the service life of the power battery is influenced. When the power battery is heated by using the waste heat of the engine, the water temperature of the engine cannot be controlled, and how to control the water inlet temperature of the power battery by an effective method is a problem which needs to be solved urgently at present, and the patent application is not described. Disclosure of Invention The invention aims to provide a power battery heating system and a water temperature control method for heating a power battery, so that the water inlet temperature for heating the power battery is controlled to be at a desired water inlet temperature, and the service life is prevented from being influenced by heating. The power battery heating system comprises a controller, a PTC heating power battery waterway, a first temperature sensor for detecting the actual water inlet temperature of a battery heat exchanger and a second temperature sensor for detecting the actual water inlet temperature of the power battery, wherein the first temperature sensor and the second temperature sensor are arranged in the PTC heating power battery waterway and are connected with the controller. The heating system further comprises a three-way proportional valve, a first three-way valve, an engine waste heat recovery waterway and a third temperature sensor, wherein the third temperature sensor is used for detecting the water temperature of the engine and connected with the controller, an inlet of the three-way proportional valve is connected with an outlet of the PTC heating power battery waterway, a first outlet of the three-way proportional valve is connected with a first inlet of the first three-way valve, an outlet of the first three-way valve is connected with an inlet of the PTC heating power battery waterway, a second outlet of the three-way proportional valve is connected with an inlet of the engine waste heat recovery waterway, and an outlet of the engine waste heat recovery waterway is connected with a second inlet of the first three-way valve. The controller is connected with the three-way proportional valve, and controls the first outlet opening and the second outlet opening of the three-way proportional valve according to the water temperature of the engine, the actual water inlet temperature of the battery heat exchanger and the actual water inlet temperature of the power battery, so that only part of engine cooling water enters the battery heat exchanger, the water temperature entering the battery heat exchanger reaches the expected water inlet temperature, and the water temperature of a pipeline entering the power battery is adjusted in real time. Preferably, the engine waste heat recovery waterway comprises a second three-way valve, a third three-way valve, a first water pump, an engine water jacket and a fourth three-way valve, wherein a first inlet of the second three-way valve is used as an inlet of the engine waste heat recovery waterway and is connected with a second outlet of the three-way proportional valve, a second inlet of the second three-way valve is connected with an outlet of an engine water storage bottle, an outlet of the second three-way valve is connected with a first inlet of the third three-way valve, a second inlet of the third three-way valve is connected with an outlet of an engine radiator, an outlet of the third three-way valve is connected with an inlet of the first water pump, an outlet of the first water pump is connected with an inlet of the fourth three-way valve, a first outlet of the fourth three-way valve is used as an outlet of t