The cooling system is an important component of the engine, and its function is to ensure that the engine can operate normally and reliably under appropriate temperature conditions under all working conditions. With the increasing intensity and compact design of modern engines, the thermal load of engines is also increasing. At the same time, the market's requirements for engines are constantly increasing, which not only need to meet the constantly increasing output power but also have good economy.
1、 Main viewpoints
In traditional cooling systems, mechanically driven cooling water pumps and cooling fans are used, and the speed of the water pumps and fans increases with the increase of engine speed. So the flow rate of the cooling medium depends on the engine speed, not the cooling amount required for the actual operating conditions of the engine, which obviously cannot reasonably control the engine temperature. Therefore, traditional cooling systems have disadvantages such as long preheating time for low-temperature cold starting, excessive cooling at low loads, overheating of low-speed and high load engines, and easy boiling points when the hot engine stops.
With the development of automotive electronic control technology, most engine cooling system radiator fans are currently driven by DC motors. The speed of the radiator fan is adjusted based on the temperature of the coolant measured by sensors, which can effectively control the cooling intensity of the engine under cold start warm-up, low load and high speed conditions, and improve the fuel economy of the engine. However, the engine's cooling water pump still uses a mechanical water pump directly driven by the engine, and the problems existing in traditional cooling systems have not been fundamentally solved. The main manifestation is the contradiction between controlling the fan speed based on the cooling water temperature and directly driving the water pump by the engine. When the engine is cold started, although the fan does not turn, the water pump runs with the engine. As a result, the continuous circulation of cooling water increases the heat dissipation around the cylinder block, especially in cold winter, which inevitably leads to longer warm-up time and increased fuel consumption during vehicle operation. On the other hand, when the engine stops heating up, the water pump stops running, and the fan still operates according to the set MAP based on the temperature of the coolant. However, the coolant circulation is not driven by the water pump and can only be cooled through natural convection heat transfer, resulting in less than ideal cooling effect. In addition, on the contrary, under high load and low speed conditions, the heat load near the engine cylinder block, cylinder head, and exhaust duct is very high, and it is necessary to accelerate the cooling water circulation speed to quickly remove excess heat. The water pump is constrained by the engine speed and cannot increase the speed, making it difficult to increase the cooling water circulation speed. Insufficient water flow through the radiator leads to an extended working time of the cooling fan, and even causes the engine to overheat.
To solve the above-mentioned problems in the engine cooling system, this system replaces the water pump directly driven by the engine with a water pump driven by a DC motor, and adopts a combination of an electronic control water pump and an electronic control fan to achieve precise control of the cooling water temperature.
This project mainly studied the matching relationship between the operating speed of the water pump and the engine working conditions. Based on this, a control and driving system for the engine cooling water pump was developed, which achieved the function of controlling the water pump speed according to the water temperature.
2、 Innovation points
1. The water pump speed can be continuously controlled based on the engine cooling water temperature. The speed of the water pump varies according to the cooling water temperature of the cylinder block, which can more effectively control the temperature inside the engine cylinder, effectively solving the problems of excessive cooling under low load and high speed conditions, and insufficient cooling under high load and low speed conditions in traditional cooling systems
2. The system can automatically adapt to 12V and 24V DC power sources, with a driving output power of up to 500W. It can be matched with parameters on the machine and is suitable for various automotive engine cooling systems.
3、 Practical significance
The development of the automotive industry is increasingly threatened and impacted by energy conservation, environmental protection, and safety. The requirements are becoming increasingly strict, and various regulations force designers to make the engine operate within the optimal operating range when developing a new generation of car engines. However, pure mechanical improvements and improvements seem to have come to an end. These improvements make the mechanism more complex, and further improvements have little effect. Electronic control components have the advantages of compact structure, high reliability, low power consumption, good responsiveness, and low cost. The improvement effect of replacing mechanical control with electronic control is significant. Therefore, the electronic control of automobiles has become an irreversible trend, and the electronic control of automobiles has also become an important symbol of the development of modern automobiles.
The intelligent cooling system that combines an electric control water pump and an electric control fan compensates for the shortcomings of the current engine cooling system, achieving the optimal correspondence between operating speed and output power at different temperatures, thereby protecting the engine from being in the optimal working state under any working condition and atmospheric environment, and further realizing the practical significance of green and environmentally friendly engines.
The electrically controlled water pump can enable the engine to use a separate water pump, which means the water pump can stay away from the hotter engine block. Therefore, the structural design and material selection of water pumps are more flexible, which is conducive to designing pumps with higher efficiency and lower costs.
