Machinery import clearance by HS code

List of the table of contents of this article:

• 1,Machinery import clearance by HS code The working principle of the large cycle and the small cycle of the engine cooling system
• 2, What is a large cycle and a small cycle
• 3, What is the flow path of the size cycle coolant of the engine cooling system?

working principle of large cycle and small cycle of engine cooling system

small cycle: when the coolant temperature is below 80℃When the paraffin wax becomes solid, the spring presses the valve on the seat, the valve closes, and the coolant flows into the air conditioner radiator inlet pipe from the side opening instead of flowing into the radiator, that is, a small cycle is carried out, and the cooling intensity of the cooling system is small.

The small circulation of the cooling system is the circulating flow of water without passing through the radiator when the water temperature is low, so that the water temperature rises. As shown below: The large circulation of the cooling system is the circulation flow of water through the radiator when the water temperature is high. As shown below: Control of large and small cycles: a thermoster is usually used to control the flow of cooling water through the radiator.

The thermoster is installed in the channel of cooling water circulation, and automatically changes the circulation route of water according to the engine load and water temperature, so as to adjust the cooling intensity of the cooling system. While ensuring the normal operating temperature of the engine, the thermostat can also realize the automatic switching between small and large cycles.

What is a large cycle and a small cycle

1. According to the process of water circulation, the water cycle can be divided into large cycles Ring (or sea and land cycle) and small cycle (including sea cycle and land cycle). The exchange of water between land and sea is called the great cycle. Due to the uneven distribution of land and sea and the effect of atmospheric circulation, several large cycles of water on the earth are formed, which change with the seasons.

2. Its principle is to pressurize the coolant in the water tank with a water pump, let the coolant flow in the water sleeve, absorb heat from the cylinder wall, and the temperature rises. The heated coolant enters the radiator, reuse the cooling fan to blow the radiator, quickly take away the heat, and finally from the bottom of the radiator. Re-enter the water sleeve, so as to keep circulating.

3. Large cycle: When the temperature of the cooling water is higher than 90 degrees Celsius, the main valve of the cooling system thermoster is opened and the bypass valve is closed. Under the action of the water pump, the coolant enters the cylinder body water sleeve from the engine cylinder head water sleeve through the main valve of the thermostor, and the coolant after cooling is pressed into the cylinder water sleeve through the water pump. Such a cycle is called a large cycle.

4. The small circulation of the cooling system is the circulating flow of water without passing through the radiator when the water temperature is low, so that the water temperature rises.As shown below: The large circulation of the cooling system is the circulation flow of water through the radiator when the water temperature is high.

5. The small cycle of the engine cooling system is that the coolant only circulates in the waterway inside the engine, and the large cycle is that the coolant cycle passes through the radiator outside the engine, that is, the water tank. The switching of the two cycle modes is done through the thermosulator. When the thermostor is turned off, a small cycle is carried out, and vice versa, a large cycle is carried out.

What is the flow path of the size cycle coolant of the engine cooling system?

The flow path of the large and small circulation coolant of the engine cooling system: the flow path of the small circulation coolant is that the coolant flows into the inlet pipe of the empty radiator from the bypass port, not into the radiator;The flow path of large circulation coolant is that the coolant can enter the radiator along the radiator inlet pipe for large circulation.

The cycle route of engine cooling water is: water sleeve thermosulator → main valve → radiator upper water chamber → cooling tube → radiator lower water chamber → water pump inlet → water pump → water sleeve. The small circulation route of engine cooling water is: water sleeve thermosulator → bypass hole → bypass pipe → pump inlet → water pump → water sleeve.

Large circulation is the circulation of water in the water tank and water in the engine. Small cycle is that the water in the engine circulates through the pump, and the water in the tank does not circulate. Large circulation: water pump → water pipe → cylinder body water sleeve → cylinder head water sleeve → thermoster → radiator inlet hose → radiator → radiator outlet hose → water pump.