How Does a Car Cooling System Work?
2 Answers
The working principle of a car cooling system is as follows: 1. Regulation of coolant flow: The regulation of coolant flow is automatically controlled by the opening and closing of the thermostat's main valve and bypass valve. The paraffin wax inside the thermostat's sensing body is solid below 76°C, begins to liquefy above 76°C, and completely turns into liquid above 86°C, expanding in volume and compressing the rubber tube to exert thrust on the central push rod. This mechanism changes the opening and closing states of the thermostat's main valve and bypass valve, thereby controlling the coolant circulation route. 2. Minor circulation: When the engine water temperature is low, the thermostat's main valve closes and the bypass valve opens, allowing the coolant to circulate within the engine in a minor loop. The coolant circulation route is: water pump → water jacket → thermostat bypass valve → minor circulation pipe → water pump. At this stage, the coolant flow path is short and the flow rate is small, facilitating rapid engine warm-up. 3. Major circulation: When the engine water temperature rises to a certain level, the thermostat's main valve opens and the bypass valve closes, enabling the coolant to circulate through the radiator in a major loop. The coolant circulation route is: radiator → water pump → water jacket thermostat → main valve → radiator. When the coolant flows through the radiator, the forced air draft from the fan dissipates heat into the air to ensure the engine temperature does not become excessively high. At this stage, the coolant flow path is long and the flow rate is large, hence it is called the major circulation.
I find the working principle of a car's cooling system quite simple, it's like installing a radiator for the engine. When the engine is running, it generates a large amount of heat, and high temperatures can lead to mechanical damage or shutdown. The cooling system solves this problem through a closed-loop design: first, a water pump pushes a specially formulated liquid (usually a mixture of water and other coolants) to circulate inside the engine, absorbing excess heat; then, this heated liquid flows to the front radiator, where air, assisted by a fan or the airflow from driving, helps cool it down; the thermostat automatically adjusts the liquid flow rate based on the engine temperature to ensure it operates at the optimal temperature. This entire process repeats continuously, ensuring the engine doesn't overheat and also improving fuel efficiency. When I drive, I often hear people say this system is crucial, especially in hot weather or during long trips. Regularly checking the coolant and radiator vents to prevent blockages can save a lot of hassle.
