Engine cooling system and cooling method therefor

An engine cooling system, comprising:

• a water jacket of an engine body;
• the water jacket of the engine body comprises:
• an upper water jacket of the engine body, which is provided with an upper water storage chamber of the engine body, and an upper cooling water chamber of a cylinder liner, which is communicated with the upper water storage chamber of the engine body;
• the engine body further comprises:
• a lower water jacket of the engine body, which is provided with a lower water storage chamber of the engine body, and a lower cooling water chamber of the cylinder liner, which is communicated with the lower water storage chamber of the engine body;
• a first valve is arranged between the lower water storage chamber of the engine body and the upper water storage chamber of the engine body, and the first valve is configured to control the communication or disconnection of the lower water storage chamber of the engine body and the upper water storage chamber of the engine body;
• and a water jacket of a cylinder head;
• the water jacket of the cylinder head comprises an upper water jacket of the cylinder head, which is provided with an upper water storage chamber of the cylinder head;
• the upper water storage chamber of the cylinder head is communicated with the upper cooling water chamber of the cylinder liner;
• a second valve is arranged between the upper water storage chamber of the cylinder head and the upper water storage chamber of the engine body, and the second valve is configured to control the communication or disconnection of the upper water storage chamber of the cylinder head and the upper water storage chamber of the engine body;
• the water jacket of the cylinder head further comprises a lower water jacket of the cylinder head, which is communicated with the lower cooling water chamber of the cylinder liner, further comprising:
• a first temperature sensor, which is configured to measure the temperature of the lower water jacket of the cylinder head;
• and a controller;
• wherein the first valve and the second valve are both electronically controlled throttle valves, and the controller controls opening or closing of the first valve according to a signal of the first temperature sensor, or the controller controls opening or closing of the second valve according to the signal of the first temperature sensor.