Battery Temperature Cycle Test Chamber Chiller

Compared with traditional vehicles, electric vehicles have higher safety requirements. Performance encourages the development of high-density, high-power, fast charging and discharging electric vehicles. The air-cooled heat dissipation used in the original electric vehicles can no longer solve the problem of battery heat dissipation. The advantages of the liquid cooling system are fast cooling rate, good temperature uniformity, and simple fluid (temperature and flow) control. Liquid cooling system has become an inevitable trend of new energy vehicles.

Because the performance, life and safety of lithium-ion batteries are very sensitive to temperature. Therefore, temperature is one of the most important factors affecting the performance of lithium-ion batteries. Due to the characteristics of lithium-ion batteries, the suitable operating temperature range is relatively narrow. Its operating temperature is 20°C~40°C, and the temperature difference between batteries should be less than 5°C.

At present, the operating data of the battery pack (PACK) liquid cooling system is blank, and new energy vehicle manufacturers cannot design the liquid cooling system of the vehicle. Automobile manufacturers need to understand the following data:

The reasonable temperature of the battery pack is 10-30°C, and the liquid cooling system may reach -40°C in low temperature weather. There is a heating block inside the battery pack to preheat before starting to play a thermal protection function. When the battery temperature exceeds 30°C after the car is driving It needs to be cooled by a -40°C liquid cooling system.

How much liquid needs to pass through at this time?

To ensure that the battery temperature is controlled within the range of 10-30°C, and the pipe diameter of the automotive liquid cooling system is fixed, then the circulation pump needs to be adjusted to control the flow. As the temperature of the car coolant changes, the flow and pressure of the coolant also need to change to ensure the battery temperature.

1. Application scenarios:

Battery Temperature Cycle Test Chamber Chiller is mainly used in the following fields in electric vehicle testing:

Liquid-cooled power battery and its management system: liquid-cooled tests for the design and development of power battery cells/modules/systems (battery packs), battery management systems, and heat sinks.

Micro motor: sunroof/side window/wiper.

Drive motor (MOTOR): single motor/dual motor/three motors/four motors/powertrain.

Drive motor controller (MCU): passenger car MCU/commercial vehicle MCU.

Charging pile: AC charging pile/DC charging pile/charging interface/charging cable.

Vehicle: OBC/DCDC.

2. Composition of Battery Temperature Cycle Test Chamber Chiller

The complete system includes compressor refrigeration unit, heating system, water circulation system, sensors, control devices and auxiliary devices, etc.

(1) Refrigeration compressor unit: The refrigeration compressor unit of this system is composed of compressor, evaporator, condenser and corresponding accessories. The refrigeration system provides a constant cold source for the whole equipment, and the temperature sensor in the refrigeration box senses the temperature inside the refrigeration box. The temperature change is uploaded to the temperature controller, and the temperature controller controls and adjusts the output cooling capacity of the compressor, so that the temperature of the refrigeration box is always controlled within the set temperature range, and the temperature value can also be set by the host computer or manually.

(2) Circulating fluid tank: The circulating fluid tank is made of stainless steel, and it is composed of a temperature sensor, a heater, etc. The circulating liquid tank detects the internal changes through the temperature sensor, and uploads to the temperature controller, and the temperature controller controls the temperature of the liquid tank by controlling the duty ratio of the cooling solenoid valve and the bypass solenoid valve. The liquid tank is connected with the tested part through the external circulation coolant pump, which provides cooling medium at various temperatures for the tested part.

(3) Circulating coolant pump: The circulating coolant pump is a high-temperature pump. A flow sensor and a pressure sensor are installed at the outlet of the circulating coolant pump. For manual control flow and pressure regulation.

(4) Temperature control system: The temperature control system is used for the temperature of each temperature control point, including the temperature of the refrigerant tank. The temperature control system adopts PT100 armored temperature sensor for temperature data collection, and uses Siemens PLC controller as the temperature controller to automatically control the temperature of each node of the whole system.

(5) Controller: The controller is used for state perception, control equipment start and stop, control linkage, control auxiliary equipment functions, etc., including liquid level sensors, etc. The switching between the two working modes is realized by the controller.

(6) Communication: The system has an analog mixed communication interface, which provides Ethernet linkage with the upper computer to realize remote control.

(7) Thermal insulation facilities: This equipment adopts foam thermal insulation measures, and implements strict thermal insulation for all low-temperature pipelines to ensure energy saving and high efficiency.

3. Main functions

(1) Intelligent control: Siemens PLC intelligent controller, intelligent display, and modular operation interface are adopted; various parameters of the equipment can be intelligently sensed, calculated, and adjusted. The temperature of the cold storage tank can be set at the same time. Manually adjust the output flow and output pressure; monitor the return liquid temperature and return liquid pressure.

(2) Rapid cooling and temperature control: This system adopts the direct cooling design, the compressor unit can meet the direct cooling in the whole temperature range, and obtain a large cooling capacity, and at the same time maintain a small amount of water in the circulating water tank during operation, still can Precise temperature control.

(4) Remote and local control: The system controller has an analog mixed communication interface, and the controller is equipped with a remote and local switch. It can realize remote local control and timely conversion.