Diesel engine variable altitude variable flow cooling system and control process thereof

Abstract

The invention discloses a diesel engine variable altitude variable flow cooling system, which includes a variable altitude variable cooling liquid flow system, a variable altitude variable cooling airflow system and a control system, wherein the variable altitude variable cooling liquid flow system includes a variable flow cooling water pump, a variable temperature thermostat, and a radiator; a cooling fan of the variable altitude variable cooling air flow system is connected with a hydraulic control device; and the control system includes an ECU, a first temperature sensor, a second temperature sensor, a flow sensor, and two cooling liquid flow sensors, wherein the first temperature sensor is installed on a cooling liquid outlet pipeline between an outlet of a diesel and the variable temperature thermostat, the second temperature sensor is installed on a cooling liquid pipeline of an outlet of the radiator, the flow sensor is installed on the cooling liquid outlet pipeline between the outlet of the diesel and the variable temperature thermostat, and the two cooling liquid flow sensors are respectively installed on two outlets of the variable temperature thermostat. According to the diesel engine variable altitude variable flow cooling system, real-time optimum control of the cooling temperature of the diesel can be realized within the altitude range of 0 to 5500 m.

Description

technical field [0001] The invention relates to the technical field of diesel engines, in particular to a diesel engine variable altitude variable flow cooling system and its control process. Background technique [0002] When vehicles, construction machinery and other power equipment are running on high altitudes, due to the deterioration of heat dissipation performance and the increase of the heat load of the diesel engine, the cooling water of the diesel engine is easy to boil, the cooling capacity of the cooling system is reduced, and the body is easy to overheat, etc. The continuous operating capacity and operating intensity in the plateau area have declined to varying degrees. These problems can be attributed to the poor matching between the cooling system of the diesel engine and the working process of the diesel engine. [0003] The traditional diesel engine cooling system is that the crankshaft of the diesel engine directly drives the cooling system components (wat...

AI Technical Summary

Problems solved by technology

The cooling capacity of this cooling system is designed according to the maximum heat load condition of the diesel engine, and cannot be adjusted in real time according to the cooling and heat dissipation requirements of the diesel engine under variable working conditions. This limitation has caused the traditional cooling system of the diesel engine to be unable to adapt to the cooling requirements of different altitudes and working conditions. , resulting in insufficient cooling at high altitudes or excessive cooling at low altitudes, and the mechanical cooling system consumes a lot of energy. The power consumption of the engine under rated operating conditions accounts for 5% to 12% of the effective output of the engine. When clutching at high speed , bringing a large thermal shock stress to the engine

Because the paraffin thermostat has the characteristics of response delay and "hysteresis", it cannot make real-time and accurate response according to the change of engine water temperature. The thermostat is not fully opened, but the cooling fan begins to strengthen the radiator. In the case of heat dissipation, since the coolant does not all flow through the radiator, the heat dissipation efficiency of the cooling fan is reduced

Adjusting the flow rate of the circulating water pump only changes the total flow rate of the coolant circulation. The specific changes in the large and small circulation flow rates of the coolant are affected by the opening of the thermostat, and the relationship between the opening of the paraffin thermostat and the temperature of the coolant There is not a one-to-one correspondence between them, and the paraffin thermostat cannot realize the precise control of the large and small circulation flow distribution of the coolant

At present, the improvement of diesel engine cooling system mainly focuses on the single control of cooling system components (such as water pump, fan, thermostat), but in the special environment of plateau, the optimal control of a single component is not enough to meet the heat dissipation requirements of diesel engines at variable altitudes , so the integrated control of the cooling system becomes a necessary means of cooling the plateau diesel engine

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