CN-121976893-A - Engine thermal management system, engineering machinery and control method of thermal management system

CN121976893ACN 121976893 ACN121976893 ACN 121976893ACN-121976893-A

Abstract

The invention discloses an engine heat management system, engineering machinery and a control method of the heat management system, belonging to the technical field of engine heat dissipation, wherein in the heat management system, an engine, a water pump and a radiator are connected on a main circulation heat dissipation loop, and a temperature sensor is arranged at an engine water outlet; the phase-change heat storage loop is connected in parallel with two ends of the radiator, the phase-change unit is connected in parallel with the radiator through the first control valve, the waste gas waste heat recovery loop is connected with the second control valve and the waste gas heat exchanger, the waste gas heat exchanger cooling liquid passage is connected in parallel with the main circulation heat dissipation loop through the second control valve, and the controller is configured to receive engine operation parameters and engine water temperature signals acquired by the temperature sensor, control the rotating speed of the water pump and the opening and closing states of the control valves according to the received data, realize the switching of cold start warm-up working condition, normal heat dissipation working condition and high load auxiliary heat dissipation working condition, and improve the heat efficiency of the engine.

Inventors

You Yanzhou
CHEN QINFA
LI JIALONG
Li Menxin
YUN LEI

Assignees

徐州徐工挖掘机械有限公司

Dates

Publication Date: 20260505
Application Date: 20260227

Claims (10)

1. The engine thermal management system is characterized by comprising a main circulation heat dissipation loop, a phase change heat storage loop, an exhaust gas waste heat recovery loop and a controller; the main circulation heat dissipation loop is sequentially connected with an engine, a water pump and a radiator, and a temperature sensor is arranged at a water outlet of the engine; The phase-change heat storage loop is connected in parallel with two ends of the radiator, a first control valve and a phase-change unit are connected to the phase-change heat storage loop, the phase-change unit is connected with the radiator in parallel through the first control valve, and the phase-change unit is used for absorbing and storing heat when the temperature of the engine is higher than the phase-change temperature and releasing heat when the temperature of the engine is lower than the phase-change temperature; The exhaust gas waste heat recovery loop is connected with a second control valve and an exhaust gas heat exchanger, an exhaust gas inlet of the exhaust gas heat exchanger is communicated with an engine exhaust port, and an exhaust gas heat exchanger cooling liquid passage is connected with the main circulation heat dissipation loop in parallel through the second control valve; The controller is configured to receive engine operation parameters and engine water temperature signals acquired by the temperature sensor, and control the rotation speed of the water pump and the opening and closing states of the control valves according to the received data, so as to realize the switching of cold start and warm working conditions, normal heat dissipation working conditions and high-load auxiliary heat dissipation working conditions.
2. The engine thermal management system of claim 1, wherein the exhaust gas waste heat recovery circuit is further connected with a third control valve and a warm air system, and the vehicle warm air system is connected in parallel with an exhaust gas heat exchanger through the third control valve; The controller is also configured to receive a warm air demand signal, control the rotation speed of the water pump and the opening and closing states of the control valves according to the warm air demand signal, and realize the switching between the heating working condition and other working conditions of the vehicle.
3. The engine thermal management system of claim 1 wherein a thermostat is also connected to the main circulation radiator circuit, the thermostat being connected between the engine and the radiator.
4. The engine thermal management system of claim 1, wherein the phase change unit has a honeycomb or coil coolant flow passage with a composite phase change material encapsulated outside the coolant flow passage.
5. The engine thermal management system of claim 1, wherein the composite phase change material is a paraffin-based material.
6. The engine thermal management system of claim 1 wherein the exhaust gas heat exchanger is disposed downstream of an engine exhaust manifold.
7. A construction machine, characterized in that the engine thermal management system according to any one of claims 1-6 is applied for managing the thermal cycle of the engine of the construction machine.
8. A control method of an engine heat management system, characterized by being applied to the engine heat management system according to any one of claims 1 to 6, comprising: acquiring an engine operation parameter and an engine water temperature signal; Judging the type of the current working condition according to the acquired data; when judging cold start and warm-up working conditions, controlling the first control valve to be closed and the second control valve to be opened, and controlling the water pump to operate at a first preset rotating speed to enable the cooling liquid to flow through the waste gas heat exchanger, and heating the cooling liquid by using waste heat of engine waste gas; When judging a normal heat radiation working condition, controlling the first control valve and the second control valve to be closed, and controlling the water pump to operate at a second preset rotating speed, so that the temperature of the engine is stabilized in an optimal efficiency interval by means of the thermostat and the radiator; When the high-load auxiliary heat dissipation working condition is judged, the first control valve is controlled to be opened, the second control valve is controlled to be closed, the water pump is controlled to operate at a third preset rotating speed, and instantaneous heat is absorbed through the phase change unit.
9. The control method of an engine heat management system according to claim 8, characterized by further comprising: acquiring a warm air demand signal; Judging the type of the current working condition according to the warm air demand signal; When the vehicle heating working condition is judged, the first control valve and the second control valve are controlled to be closed, the third control valve is controlled to be opened, and the high-temperature cooling liquid heated by the exhaust gas heat exchanger is supplied to a vehicle warm air system.
10. The control method of an engine thermal management system according to claim 9, wherein the determination method of the operating mode type includes: when the temperature of the water of the engine is not more than 5 ℃, judging a cold start warming working condition; When the temperature of the engine is between 75 ℃ and 95 ℃, judging a normal heat dissipation working condition; when the temperature of the water of the engine is not less than 95 ℃, judging a high-load auxiliary heat dissipation working condition; when a warm air demand signal is acquired, judging a vehicle heating condition; the priority descending order of the working condition types is that the vehicle heating working condition, the cold start warming working condition, the high-load auxiliary heat dissipation working condition and the normal heat dissipation working condition are ordered.

Description

Engine thermal management system, engineering machinery and control method of thermal management system Technical Field The invention belongs to the technical field of engine heat dissipation, and particularly relates to an engine heat management system, engineering machinery and a control method of the heat management system. Background In operation of the engine, only about one third of the heat generated by combustion of the fuel is converted to useful work, and the remainder of the heat is dissipated to the environment primarily through the exhaust and cooling systems. Conventional engine cooling systems rely primarily on paraffin thermostats, mechanical water pumps, and radiators, the modes of operation of which are relatively passive and fixed. Because the working condition of engineering machinery is complex, frequent idling, high-load burst and shutdown switching exist, the thermal load fluctuation of an engine is severe, and the traditional cooling system is difficult to deal with. The prior art makes some improvements in the traditional heat dissipation system, such as adopting an electronic water pump and an electronic thermostat to realize more flexible cooling control or attempting to recover waste heat of waste gas, but the solutions often have single functions and do not have the function of solving various heat dissipation problems. For example, cold start problems may exist in which the engine is cold started, the coolant temperature is low, the lubricant viscosity is high, resulting in increased friction loss, poor fuel economy, and increased emissions of pollutants (e.g., HC, CO). The traditional system needs a long time to enable the engine to reach the optimal working temperature, and the problem of insufficient heat load abrupt change is solved, namely the instantaneous heat generation quantity of the engine is increased rapidly under the working conditions of rapid acceleration, heavy load climbing and the like, and the traditional cooling system has a response lag, so that the engine is possibly overheated and knocking is caused. Therefore, there is a need to design an engine thermal management system that can solve various heat dissipation problems of the engine and improve thermal efficiency. Disclosure of Invention The invention aims to provide an engine thermal management system, engineering machinery and a control method of the thermal management system, wherein a phase-change heat storage loop is connected in parallel with two ends of a radiator, an exhaust gas waste heat recovery loop is connected in parallel with a main circulation heat dissipation loop, and the opening and closing of each valve and the rotating speed of a water pump are controlled by combining a thermal management strategy, so that the working condition switching of cold start warming, normal heat dissipation and high load heat dissipation is realized, the heat efficiency is improved, and the energy consumption is reduced. In order to achieve the above purpose, the invention is realized by adopting the following technical scheme: in a first aspect, the invention provides an engine thermal management system comprising a main circulation heat dissipation loop, a phase change heat storage loop, an exhaust gas waste heat recovery loop and a controller; the main circulation heat dissipation loop is sequentially connected with an engine, a water pump and a radiator, and a temperature sensor is arranged at a water outlet of the engine; The phase-change heat storage loop is connected in parallel with two ends of the radiator, a first control valve and a phase-change unit are connected to the phase-change heat storage loop, the phase-change unit is connected with the radiator in parallel through the first control valve, and the phase-change unit is used for absorbing and storing heat when the temperature of the engine is higher than the phase-change temperature and releasing heat when the temperature of the engine is lower than the phase-change temperature; The exhaust gas waste heat recovery loop is connected with a second control valve and an exhaust gas heat exchanger, an exhaust gas inlet of the exhaust gas heat exchanger is communicated with an engine exhaust port, and an exhaust gas heat exchanger cooling liquid passage is connected with the main circulation heat dissipation loop in parallel through the second control valve; The controller is configured to receive engine operation parameters and engine water temperature signals acquired by the temperature sensor, and control the rotation speed of the water pump and the opening and closing states of the control valves according to the received data, so as to realize the switching of cold start and warm working conditions, normal heat dissipation working conditions and high-load auxiliary heat dissipation working conditions. Optionally, the waste gas waste heat recovery loop is also connected with a third control valve and a warm air system, and the vehicle warm