A composite cooling method and system for an explosion-proof diesel engine

Abstract

The application relates to a composite cooling method and system of an explosion-proof diesel engine, which comprises the following steps: collecting the cooling water temperature, the diesel engine rotating speed, the supercharging pressure and the intake air temperature of the explosion-proof diesel engine; determining the cooling control strategy according to the cooling water temperature; when the single control strategy is determined, the fan rotating speed of the cooling fan of the explosion-proof diesel engine is controlled to realize the cooling control; when the double collaborative control strategy is determined, the fan rotating speed of the cooling fan of the explosion-proof diesel engine and the flow of the cooling water pump are controlled to realize the cooling control; when the three collaborative control strategy is determined, the fan rotating speed, the flow of the cooling water pump and the pre-turbine exhaust temperature are controlled to realize the cooling control of the diesel engine; the application solves the problem that high temperature appears when the explosion-proof diesel engine runs under heavy load, long distance and large slope, the engine is extinguished, and the normal work of the explosion-proof diesel engine is affected, and the running safety and stability of the explosion-proof diesel engine are improved.

Description

Technical Field

[0001] This invention relates to the field of cooling technology for explosion-proof diesel engines, and more specifically to a composite cooling method and system for explosion-proof diesel engines. Background Technology

[0002] According to standards, explosion-proof diesel engines used in coal mines must maintain a surface temperature below 150°C. Therefore, compared to ordinary ground-based diesel engines, they require not only cooling of the engine itself but also water cooling of external high-temperature components such as the exhaust manifold, turbocharger, and turbocharger exhaust tailpipe to ensure that the temperature of any part of the engine surface remains below 150°C to meet explosion-proof requirements. Existing cooling systems for explosion-proof diesel engines often experience overheating or even overheating in high-power applications, especially during long-distance, steep inclines, affecting normal engine operation. Current solutions, such as single-cycle cooling systems or dual-cycle cooling systems with a second water pump, are insufficient to meet efficient heat dissipation requirements, particularly during heavy-load, long-distance, steep incline operations, leading to engine stalling and disrupting the normal operation of the explosion-proof diesel engine. Summary of the Invention

[0003] In order to solve the technical problems in the prior art, such as high temperature during heavy-load, long-distance, steep-gradient operation, which causes engine stalling and affects the normal operation of explosion-proof diesel engines, the present invention provides a composite cooling method and system for explosion-proof diesel engines.

[0004] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0005] A composite cooling method for an explosion-proof diesel engine includes the following steps:

[0006] Collect data on the cooling water temperature, engine speed, boost pressure, and intake air temperature of the explosion-proof diesel engine.

[0007] A cooling control strategy is determined based on the cooling water temperature; wherein, the cooling control strategy includes a single control strategy, a dual-cooperative control strategy, and a triple-cooperative control strategy;

[0008] When the cooling control strategy is determined to be the single control strategy, the fan speed of the cooling fan of the explosion-proof diesel engine is controlled according to the cooling water temperature and the diesel engine speed to achieve cooling control of the explosion-proof diesel engine.

[0009] When the cooling control strategy is determined to be the dual-cooperative control strategy, the fan speed of the cooling fan of the explosion-proof diesel engine is controlled according to the cooling water temperature and the diesel engine speed, and the flow rate of the cooling water pump is controlled according to the cooling water temperature and the diesel engine speed, so as to achieve cooling control of the explosion-proof diesel engine.

[0010] When the cooling control strategy is determined to be a three-coordinated control strategy, the fan speed of the cooling fan of the explosion-proof diesel engine is controlled according to the cooling water temperature and the diesel engine speed, the flow rate of the cooling water pump is controlled according to the cooling water temperature and the diesel engine speed, and the turbine exhaust temperature of the explosion-proof diesel engine is controlled according to the diesel engine speed, the boost pressure and the intake air temperature, so as to achieve cooling control of the explosion-proof diesel engine.

[0011] The beneficial effects of this invention are as follows: Cooling control of the explosion-proof diesel engine is achieved by adjusting the fan speed of the cooling fan under a single control strategy; cooling control of the explosion-proof diesel engine is achieved by adjusting the fan speed of the cooling fan and the flow rate of the cooling water pump under a dual-cooperative control strategy; and cooling control of the explosion-proof diesel engine is achieved by simultaneously adjusting the fan speed of the cooling fan and the flow rate of the cooling water pump and controlling the turbine exhaust temperature of the explosion-proof diesel engine under a triple-cooperative control strategy. This allows for diverse cooling control methods for the diesel engine, enabling the selection of appropriate cooling control methods based on the actual operating conditions of the explosion-proof diesel engine. It solves the problem of high temperatures during heavy-load, long-distance, and steep-gradient operation, which leads to engine stalling and affects the normal operation of the explosion-proof diesel engine, thus improving the operational safety and stability of the explosion-proof diesel engine.

[0012] Based on the above technical solution, the present invention can be further improved as follows.

[0013] Furthermore, determining a cooling control strategy based on the cooling water temperature includes the following steps:

[0014] When the cooling water temperature is less than or equal to the first preset threshold, the cooling control strategy is determined to be the single control strategy.

[0015] When the cooling water temperature is greater than a first preset threshold and less than a second preset threshold, the cooling control strategy is determined to be the dual-cooperative control strategy.

[0016] When the cooling water temperature is greater than or equal to the second preset threshold, the cooling control strategy is determined to be the three-coordinated control strategy; wherein the first preset threshold is less than the second preset threshold.

[0017] Furthermore, the first preset threshold is 75°C, and the second preset threshold is 90°C.

[0018] Furthermore, controlling the fan speed of the cooling fan of the explosion-proof diesel engine based on the cooling water temperature and the diesel engine speed includes the following steps:

[0019] Construct a fan speed mapping table and a fan pulse width modulation duty cycle mapping table; wherein, the fan speed mapping table is a two-dimensional table, and the fan pulse width modulation duty cycle mapping table is a one-dimensional table; the rows of the fan speed mapping table represent the diesel engine speed, the columns of the fan speed mapping table represent the coolant temperature, and the fields of the fan speed mapping table represent the reference value of the fan speed; the rows of the fan pulse width modulation duty cycle mapping table represent the fan speed, and the fields of the fan pulse width modulation duty cycle mapping table represent the pulse width modulation duty cycle of the cooling fan;

[0020] The fan speed is obtained by looking up the fan speed mapping table based on the cooling water temperature and the diesel engine speed.

[0021] The pulse width modulation duty cycle of the cooling fan is obtained by looking up the fan pulse width modulation duty cycle mapping table based on the fan speed.

[0022] The fan speed of the explosion-proof diesel engine is controlled by pulse width modulation (PWM) based on the PWM duty cycle of the cooling fan.

[0023] Furthermore, controlling the flow rate of the cooling water pump based on the cooling water temperature and the diesel engine speed includes the following steps:

[0024] Construct a pump motor speed mapping table and a pump motor pulse width modulation duty cycle mapping table; wherein, the pump motor speed mapping table is a two-dimensional table, and the pump motor pulse width modulation duty cycle mapping table is a one-dimensional table; the rows of the pump motor speed mapping table represent the diesel engine speed, the columns of the pump motor speed mapping table represent the cooling water temperature, and the fields of the pump motor speed mapping table represent the pump motor speed of the cooling water pump; the rows of the pump motor pulse width modulation duty cycle mapping table represent the pump motor speed, and the fields of the pump motor pulse width modulation duty cycle mapping table represent the pulse width modulation duty cycle of the pump motor of the cooling water pump. ；

[0025] The pump motor speed is obtained by looking up the pump motor speed mapping table based on the cooling water temperature and the diesel engine speed.

[0026] The pulse width modulation duty cycle of the pump motor is obtained by looking up the pulse width modulation duty cycle mapping table based on the pump motor speed.

[0027] The flow rate of the cooling water pump is controlled by using a pulse width modulation method based on the pulse width modulation duty cycle of the pump motor.

[0028] Furthermore, the turbine exhaust temperature of the explosion-proof diesel engine is controlled based on the diesel engine speed, the boost pressure, and the intake air temperature. The specific steps are as follows:

[0029] The injection advance angle of the explosion-proof diesel engine is controlled according to the diesel engine speed, the boost pressure and the intake air temperature, so as to control the turbine exhaust temperature of the explosion-proof diesel engine.

[0030] Furthermore, controlling the injection advance angle of the explosion-proof diesel engine based on the diesel engine speed, the boost pressure, and the intake air temperature includes the following steps:

[0031] Construct a basic exhaust temperature mapping table, a boost pressure exhaust temperature correction mapping table, and an intake air temperature exhaust temperature correction mapping table; wherein, the basic exhaust temperature mapping table, the boost pressure exhaust temperature correction mapping table, and the intake air temperature exhaust temperature correction mapping table are all two-dimensional tables; the rows of the basic exhaust temperature mapping table represent the diesel engine speed, the columns of the basic exhaust temperature mapping table represent the cyclic fuel injection quantity of the explosion-proof diesel engine, and the fields of the basic exhaust temperature mapping table represent the basic exhaust temperature value; the rows of the boost pressure exhaust temperature correction mapping table represent the diesel engine speed, the columns of the boost pressure exhaust temperature correction mapping table represent the boost pressure, and the fields of the boost pressure exhaust temperature correction mapping table represent the boost pressure exhaust temperature correction value; the rows of the intake air temperature exhaust temperature correction mapping table represent the speed of the explosion-proof diesel engine, the columns of the intake air temperature exhaust temperature correction mapping table represent the intake air temperature value of the explosion-proof diesel engine, and the fields of the intake air temperature exhaust temperature correction mapping table represent the intake air temperature exhaust temperature correction value.

[0032] The basic exhaust temperature value is retrieved from the basic exhaust temperature mapping table based on the diesel engine speed and the cyclic fuel injection quantity.

[0033] Based on the diesel engine speed and the boost pressure, the boost pressure exhaust temperature correction value is looked up in the boost pressure exhaust temperature correction mapping table;

[0034] Based on the diesel engine speed and intake air temperature, look up the intake air temperature and exhaust air temperature correction value in the intake air temperature and exhaust air temperature correction mapping table;

[0035] The turbine inlet exhaust temperature of the explosion-proof diesel engine is calculated based on the basic exhaust temperature value, the boost pressure exhaust temperature correction value, and the intake air temperature exhaust temperature correction value.

[0036] The injection advance angle of the explosion-proof diesel engine is controlled based on the turbine exhaust temperature.

[0037] Furthermore, the cooling fan is an electrically controlled fan, and the cooling water pump is an electrically controlled water pump.

[0038] To address the aforementioned technical problems, the present invention also provides a composite cooling system for an explosion-proof diesel engine, the technical details of which are as follows:

[0039] A composite cooling system for an explosion-proof diesel engine, comprising:

[0040] The data acquisition module is used to collect data on the cooling water temperature, engine speed, boost pressure, and intake air temperature of the explosion-proof diesel engine.

[0041] The data processing module is used to determine a cooling control strategy based on the cooling water temperature; wherein the cooling control strategy includes a single control strategy, a dual-cooperative control strategy, and a triple-cooperative control strategy.

[0042] The control module is used to control the fan speed of the cooling fan of the explosion-proof diesel engine according to the cooling water temperature and the diesel engine speed when the cooling control strategy is determined to be the single control strategy, so as to realize the cooling control of the explosion-proof diesel engine.

[0043] The control module is also used to control the fan speed of the cooling fan of the explosion-proof diesel engine according to the cooling water temperature and the diesel engine speed when the cooling control strategy is determined to be the dual cooperative control strategy, and to control the flow rate of the cooling water pump according to the cooling water temperature and the diesel engine speed, so as to realize the cooling control of the explosion-proof diesel engine.

[0044] The control module is also used to control the fan speed of the cooling fan of the explosion-proof diesel engine according to the cooling water temperature and the diesel engine speed when the cooling control strategy is determined to be a three-coordinated control strategy, control the flow rate of the cooling water pump according to the cooling water temperature and the diesel engine speed, and control the turbine exhaust temperature of the explosion-proof diesel engine according to the diesel engine speed, the boost pressure and the intake air temperature, so as to achieve cooling control of the explosion-proof diesel engine.

[0045] To address the aforementioned technical problems, the present invention also provides an explosion-proof diesel engine, the technical details of which are as follows:

[0046] An explosion-proof diesel engine includes an explosion-proof diesel engine cooling system, wherein the explosion-proof diesel engine cooling system uses the above-mentioned composite cooling method of the explosion-proof diesel engine to achieve cooling control of the explosion-proof diesel engine. Attached Figure Description

[0047] Figure 1 This is a flowchart illustrating a composite cooling method for an explosion-proof diesel engine according to an embodiment of the present invention.

[0048] Figure 2 This is a structural block diagram of a composite cooling system for an explosion-proof diesel engine according to an embodiment of the present invention;

[0049] Figure 3 This is a schematic diagram of the structure of the explosion-proof diesel engine cooling system in an embodiment of the present invention. Detailed Implementation

[0050] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0051] like Figure 1 As shown, this embodiment provides a composite cooling method for an explosion-proof diesel engine, including the following steps:

[0052] S1. Collect the cooling water temperature, engine speed, boost pressure, and intake air temperature of the explosion-proof diesel engine;

[0053] S2. Determine a cooling control strategy based on the cooling water temperature; wherein, the cooling control strategy includes a single control strategy, a dual-cooperative control strategy, and a triple-cooperative control strategy;

[0054] Determining a cooling control strategy based on the cooling water temperature includes the following steps:

[0055] S201. When the cooling water temperature is less than or equal to the first preset threshold, the cooling control strategy is determined to be the single control strategy.

[0056] S202. When the cooling water temperature is greater than the first preset threshold and less than the second preset threshold, the cooling control strategy is determined to be the dual-cooperative control strategy.

[0057] S203. When the cooling water temperature is greater than or equal to the second preset threshold, the cooling control strategy is determined to be the three-coordinated control strategy; wherein, the first preset threshold is less than the second preset threshold, the first preset threshold can be 75℃, and the second preset threshold can be 90℃.

[0058] S3. When the cooling control strategy is determined to be the single control strategy, the fan speed of the cooling fan of the explosion-proof diesel engine is controlled according to the cooling water temperature and the diesel engine speed to achieve cooling control of the explosion-proof diesel engine. The cooling fan is an electrically controlled fan, preferably a pulse-controlled fan, meaning the fan motor is a pulse-controlled motor. When the cooling water temperature is high, the fan speed is controlled to operate at a higher speed, thereby increasing the airflow through the radiator and achieving a better cooling effect. Compared with traditional mechanical cooling fans, the electrically controlled fan can be controlled according to the cooling water temperature and the diesel engine speed, while the traditional mechanical cooling fan is only related to the diesel engine speed. Therefore, this invention can regulate the cooling fan speed through the cooling water temperature, saving energy.

[0059] Controlling the fan speed of the cooling fan of the explosion-proof diesel engine based on the cooling water temperature and the diesel engine speed includes the following steps:

[0060] S301. Construct a fan speed mapping table and a fan pulse width adjustment duty cycle mapping table; wherein, the fan speed mapping table is shown in Table 1, the fan speed mapping table is a two-dimensional table, the rows of the fan speed mapping table represent the diesel engine speed, the columns of the fan speed mapping table represent the coolant temperature, and the fields of the fan speed mapping table represent the reference value of the fan speed.

[0061] Table 1 Fan Speed ​​Mapping Table

[0062]

[0063]

[0064] Specifically, the fan pulse width modulation duty cycle mapping table is shown in Table 2. The fan pulse width modulation duty cycle mapping table is a one-dimensional table. The rows of the fan pulse width modulation duty cycle mapping table represent the fan speed, and the fields of the fan pulse width modulation duty cycle mapping table represent the pulse width modulation duty cycle of the cooling fan.

[0065] Table 2 Fan Pulse Width Adjustment Duty Cycle Mapping Table

[0066] Fan speed 800 900 1000 1200 1400 1600 1800 2000 2200 2300 2400 PWM duty cycle 10％ 12％ 14％ 16％ 18％ 20％ 22％ 24％ 26％ 28％ 30％

[0067] S302. The fan speed is obtained by looking up the fan speed in the fan speed mapping table based on the cooling water temperature and the diesel engine speed. The fan speed is obtained by looking up the table, that is, the fan speed is obtained by looking up the corresponding diesel engine speed and the cooling water temperature in the reference values ​​of multiple fan speeds in the fan speed mapping table.

[0068] S303. Based on the fan speed, the pulse width modulation duty cycle of the cooling fan is obtained by querying the fan pulse width modulation duty cycle mapping table;

[0069] S304. The fan speed of the explosion-proof diesel engine's cooling fan is controlled according to the pulse width modulation duty cycle of the cooling fan using a pulse width modulation method.

[0070] S4. When the cooling control strategy is determined to be the dual-cooperative control strategy, the fan speed of the cooling fan of the explosion-proof diesel engine is controlled according to the cooling water temperature and the diesel engine speed, and the flow rate of the cooling water pump is controlled according to the cooling water temperature and the diesel engine speed, so as to achieve cooling control of the explosion-proof diesel engine; wherein, the cooling water pump is an electronically controlled water pump, preferably a pulse-controlled water pump, that is, the pump motor of the cooling water pump is a pulse-controlled motor. The controller drives the fan motor to rotate according to the queried duty cycle signal. At the same time, the controller can monitor the operating status of the electronic water pump and issue an alarm when an abnormality is detected, thereby improving the reliability and safety of the cooling system.

[0071] Controlling the flow rate of the cooling water pump based on the cooling water temperature and the diesel engine speed includes the following steps:

[0072] S401. Construct a pump motor speed mapping table and a pump motor pulse width modulation duty cycle mapping table; wherein, the pump motor speed mapping table is a two-dimensional table, and the pump motor pulse width modulation duty cycle mapping table is a one-dimensional table; the rows of the pump motor speed mapping table represent the diesel engine speed, the columns of the pump motor speed mapping table represent the cooling water temperature, and the fields of the pump motor speed mapping table represent the reference value of the pump motor speed of the cooling water pump; the rows of the pump motor pulse width modulation duty cycle mapping table represent the pump motor speed, and the fields of the pump motor pulse width modulation duty cycle mapping table represent the pulse width modulation duty cycle of the pump motor of the cooling water pump. ；

[0073] S402. The pump motor speed is obtained by querying the pump motor speed mapping table based on the cooling water temperature and the diesel engine speed; specifically, the pump motor speed is obtained by querying the reference value corresponding to the cooling water temperature and the diesel engine speed from multiple reference values ​​of pump motor speed in the pump motor speed mapping table.

[0074] S403. Based on the pump motor speed, the pulse width modulation duty cycle of the pump motor is obtained by querying the pump motor pulse width modulation duty cycle mapping table;

[0075] S404. The flow rate of the cooling water pump is controlled by using a pulse width modulation method based on the pulse width modulation duty cycle of the pump motor.

[0076] In the prior art, explosion-proof diesel engines for coal mines use mechanical water pumps, and the water pump flow rate is only related to the engine speed and has no direct relationship with the cooling water temperature of the explosion-proof diesel engine. In the embodiments of the present invention, an electronic water pump is used, which can link the cooling water temperature with the water pump flow rate, and control the cooling water flow rate according to the cooling water temperature, thereby achieving a better cooling effect.

[0077] The electric water pump can adjust its speed and flow rate in real time according to the engine's operating conditions and temperature changes. For example, when the explosion-proof diesel engine is first started, the coolant demand is low, and the electric water pump will operate at a lower speed to save energy; while when the engine is running at high speed or under heavy load, the electric water pump will increase its speed and increase the coolant flow rate to ensure that the engine is adequately cooled. At the same time, the controller can monitor the water pump's operating status and issue an alarm when an abnormality is detected, improving the reliability and safety of the cooling system.

[0078] The water pump operates in three states: high flow, medium flow, and low flow. When the diesel engine is just started and the water temperature is below 60°C, the controller controls the water pump to enter the low flow state. When the coolant temperature is between 60°C and 85°C, the controller controls the water pump to enter the medium flow state. When the engine coolant temperature exceeds 85°C, the controller controls the water pump to enter the high flow state.

[0079] S5. When the cooling control strategy is determined to be a three-coordinated control strategy, the fan speed of the cooling fan of the explosion-proof diesel engine is controlled according to the cooling water temperature and the diesel engine speed, the flow rate of the cooling water pump is controlled according to the cooling water temperature and the diesel engine speed, and the turbine exhaust temperature of the explosion-proof diesel engine is controlled according to the diesel engine speed, the boost pressure and the intake air temperature, so as to achieve cooling control of the explosion-proof diesel engine.

[0080] The turbine exhaust temperature of the explosion-proof diesel engine is controlled based on the diesel engine speed, the boost pressure, and the intake air temperature. The specific steps are as follows:

[0081] The injection advance angle of the explosion-proof diesel engine is controlled according to the diesel engine speed, the boost pressure and the intake air temperature, so as to control the turbine exhaust temperature of the explosion-proof diesel engine.

[0082] Specifically, controlling the injection advance angle of the explosion-proof diesel engine based on the diesel engine speed, the boost pressure, and the intake air temperature includes the following steps:

[0083] S501. Construct a basic exhaust temperature mapping table, a boost pressure exhaust temperature correction mapping table, and an intake air temperature exhaust temperature correction mapping table; wherein, the basic exhaust temperature mapping table, the boost pressure exhaust temperature correction mapping table, and the intake air temperature exhaust temperature correction mapping table are all two-dimensional tables; the rows of the basic exhaust temperature mapping table represent the diesel engine speed, the columns of the basic exhaust temperature mapping table represent the cyclic fuel injection quantity of the explosion-proof diesel engine, and the fields of the basic exhaust temperature mapping table represent the basic exhaust temperature value; the rows of the boost pressure exhaust temperature correction mapping table represent the diesel engine speed, the columns of the boost pressure exhaust temperature correction mapping table represent the boost pressure, and the fields of the boost pressure exhaust temperature correction mapping table represent the boost pressure exhaust temperature correction value; the rows of the intake air temperature exhaust temperature correction mapping table represent the speed of the explosion-proof diesel engine, the columns of the intake air temperature exhaust temperature correction mapping table represent the intake air temperature value of the explosion-proof diesel engine, and the fields of the intake air temperature exhaust temperature correction mapping table represent the intake air temperature exhaust temperature correction value.

[0084] S502. Query the basic exhaust temperature value in the basic exhaust temperature mapping table according to the diesel engine speed and the cyclic fuel injection quantity;

[0085] S503. Based on the diesel engine speed and the boost pressure, query the boost pressure exhaust temperature correction value in the boost pressure exhaust temperature correction mapping table;

[0086] S504. Based on the diesel engine speed and intake air temperature, look up the intake air temperature and exhaust air temperature correction value in the intake air temperature and exhaust air temperature correction mapping table.

[0087] S505. Calculate the turbine inlet exhaust temperature of the explosion-proof diesel engine based on the basic exhaust temperature value, the boost pressure exhaust temperature correction value, and the intake air temperature exhaust temperature correction value; specifically, calculate the sum of the basic exhaust temperature value, the boost pressure exhaust temperature correction value, and the intake air temperature exhaust temperature correction value to obtain the turbine inlet exhaust temperature.

[0088] S506. Control the injection advance angle of the explosion-proof diesel engine according to the turbine exhaust temperature.

[0089] The injection advance angle of the explosion-proof diesel engine is controlled based on the turbine exhaust temperature, and the specific method is as follows:

[0090] When the final exhaust temperature before the turbine exceeds the current operating condition limit, i.e. the preset exhaust temperature value, the exhaust temperature is first reduced by increasing the injection advance angle, but the total injection advance angle increment cannot exceed the injection advance angle increment limit.

[0091] If the exhaust temperature still exceeds the limit after the injection advance angle is increased to the maximum value, the exhaust temperature will continue to be reduced by increasing the injection pressure. However, the increase in injection pressure cannot exceed the preset injection pressure limit.

[0092] When the exhaust temperature in front of the turbine is still higher than the preset exhaust temperature after the injection pressure increases to the maximum value, the exhaust temperature is reduced by decreasing the amount of circulating fuel injection. The amount of circulating fuel injection is continuously reduced until the exhaust temperature in front of the turbine of the diesel engine does not exceed the limit.

[0093] This invention achieves cooling control of the explosion-proof diesel engine by adjusting the cooling fan speed under a single control strategy, adjusting the cooling fan speed and cooling water pump flow rate under a dual-cooperative control strategy, and simultaneously controlling the turbine exhaust temperature under a triple-cooperative control strategy. This diversifies the cooling control of the diesel engine, allowing for the selection of appropriate cooling control methods based on the actual operating conditions of the explosion-proof diesel engine. It solves the problem of high temperatures during heavy-load, long-distance, steep-gradient operation, which can cause engine stalling and affect the normal operation of the explosion-proof diesel engine, thus improving the operational safety and stability of the explosion-proof diesel engine.

[0094] In other embodiments, a composite cooling system for an explosion-proof diesel engine is also provided, the technical details of which are as follows:

[0095] A composite cooling system for an explosion-proof diesel engine, comprising:

[0096] The data acquisition module is used to collect the cooling water temperature, diesel engine speed, boost pressure, and intake air temperature of the explosion-proof diesel engine.

[0097] The data processing module is used to determine a cooling control strategy based on the cooling water temperature; wherein the cooling control strategy includes a single control strategy, a dual-cooperative control strategy, and a triple-cooperative control strategy.

[0098] The control module is used to control the fan speed of the cooling fan of the explosion-proof diesel engine according to the cooling water temperature and the diesel engine speed when the cooling control strategy is determined to be the single control strategy, so as to realize the cooling control of the explosion-proof diesel engine.

[0099] The control module is also used to control the fan speed of the cooling fan of the explosion-proof diesel engine according to the cooling water temperature and the diesel engine speed, and to control the flow rate of the cooling water pump according to the cooling water temperature and the diesel engine speed, so as to achieve cooling control of the explosion-proof diesel engine when the cooling control strategy is determined to be the dual cooperative control strategy.

[0100] The control module is also used to control the fan speed of the cooling fan of the explosion-proof diesel engine according to the cooling water temperature and the diesel engine speed when the cooling control strategy is determined to be a three-coordinated control strategy, control the flow rate of the cooling water pump according to the cooling water temperature and the diesel engine speed, and control the turbine exhaust temperature of the explosion-proof diesel engine according to the diesel engine speed, the boost pressure and the intake air temperature, so as to achieve cooling control of the explosion-proof diesel engine.

[0101] The data acquisition module, data processing module, and control module can be functional modules in a control software system, or specific electronic control hardware modules or specific devices.

[0102] In some other embodiments, an explosion-proof diesel engine is also provided, including an explosion-proof diesel engine cooling system, wherein the explosion-proof diesel engine cooling system uses the above-mentioned composite cooling method for the explosion-proof diesel engine to achieve cooling control of the explosion-proof diesel engine.

[0103] like Figure 3As shown, the explosion-proof diesel engine cooling system includes an internal circulation system and an external circulation system. The internal circulation system includes a radiator located on the left, a first explosion-proof electronically controlled water pump, a diesel engine cylinder block water jacket, a diesel engine cylinder head water jacket, and a thermostat. Coolant circulates within the internal circulation system to cool key engine components. The internal circulation system is divided into a small circulation and a large circulation. When the coolant temperature is lower than the thermostat's opening temperature, it is in the small circulation, where the coolant flows sequentially through the first explosion-proof electronically controlled water pump, the diesel engine cylinder block water jacket, the diesel engine cylinder head water jacket, the thermostat, and back to the first explosion-proof electronically controlled water pump, without flowing through the radiator. When the coolant temperature is higher than the thermostat's opening temperature, it is in the large circulation. The large circulation has two scenarios: one is when the thermostat is not fully open, in which case the coolant flows sequentially through the first explosion-proof electronically controlled water pump, the diesel engine cylinder block water jacket, the diesel engine cylinder head water jacket, and after passing the thermostat, part returns to the radiator for cooling, while part flows directly through the first explosion-proof electronically controlled water pump. Another configuration involves the thermostat fully open, in which case the coolant flows sequentially through the first explosion-proof electronically controlled water pump, the diesel engine block water jacket, the diesel engine cylinder head water jacket, and finally returns to the radiator for cooling after passing through the thermostat. Simultaneously, an exhaust pipe is installed at a high point on the diesel engine cylinder head, where gases are prone to be generated, leading to the expansion tank to prevent gases in the circulation system from affecting the coolant circulation effect. The internal circulation system is a series circulation system.

[0104] The external circulation system includes the radiator on the right, a second explosion-proof electronically controlled water pump, a water-cooled exhaust manifold, an explosion-proof water-cooled turbocharger, and an explosion-proof exhaust bellows. The external circulation system is primarily responsible for cooling the high-temperature components through which the engine's high-temperature exhaust flows. Considering that the external circulation system is mainly related to exhaust temperature, to ensure cooling efficiency—that is, to allow the coolant to carry away more heat when it enters the high-temperature components—a parallel circulation system is adopted. The coolant, after passing through the second water pump, enters in parallel through the water-cooled exhaust manifold, the explosion-proof water-cooled turbocharger, and the explosion-proof exhaust bellows, cooling these three high-temperature components before returning to the radiator for further cooling. Simultaneously, exhaust pipes are installed at the highest points of the water-cooled exhaust manifold and the explosion-proof water-cooled turbocharger, components prone to gas generation, leading to the expansion tank, to prevent gas in the circulation system from affecting the coolant circulation effect.

[0105] To achieve complete independence between the internal and external circulation systems, and to avoid the influence of the external circulation system on the internal circulation system, the radiator is divided into left and right sides, which are completely separated to effectively distribute the cooling load and improve heat dissipation efficiency.

[0106] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the concept and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A composite cooling method for an explosion-proof diesel engine, characterized in that, Includes the following steps: Collect data on the cooling water temperature, engine speed, boost pressure, and intake air temperature of the explosion-proof diesel engine. A cooling control strategy is determined based on the cooling water temperature; wherein, the cooling control strategy includes a single control strategy, a dual-cooperative control strategy, and a triple-cooperative control strategy; When the cooling control strategy is determined to be the single control strategy, the fan speed of the cooling fan of the explosion-proof diesel engine is controlled according to the cooling water temperature and the diesel engine speed to achieve cooling control of the explosion-proof diesel engine. When the cooling control strategy is determined to be the dual-cooperative control strategy, the fan speed of the cooling fan of the explosion-proof diesel engine is controlled according to the cooling water temperature and the diesel engine speed, and the flow rate of the cooling water pump is controlled according to the cooling water temperature and the diesel engine speed, so as to achieve cooling control of the explosion-proof diesel engine. When the cooling control strategy is determined to be a three-coordinated control strategy, the fan speed of the cooling fan of the explosion-proof diesel engine is controlled according to the cooling water temperature and the diesel engine speed, the flow rate of the cooling water pump is controlled according to the cooling water temperature and the diesel engine speed, and the turbine exhaust temperature of the explosion-proof diesel engine is controlled according to the diesel engine speed, the boost pressure and the intake air temperature, so as to achieve cooling control of the explosion-proof diesel engine.

2. The composite cooling method for an explosion-proof diesel engine according to claim 1, characterized in that, Determining a cooling control strategy based on the cooling water temperature includes the following steps: When the cooling water temperature is less than or equal to the first preset threshold, the cooling control strategy is determined to be the single control strategy. When the cooling water temperature is greater than a first preset threshold and less than a second preset threshold, the cooling control strategy is determined to be the dual-cooperative control strategy. When the cooling water temperature is greater than or equal to the second preset threshold, the cooling control strategy is determined to be the three-coordinated control strategy; Wherein, the first preset threshold is less than the second preset threshold.

3. The composite cooling method for an explosion-proof diesel engine according to claim 2, characterized in that, The first preset threshold is 75°C, and the second preset threshold is 90°C.

4. The composite cooling method for an explosion-proof diesel engine according to claim 1, characterized in that, Controlling the fan speed of the cooling fan of the explosion-proof diesel engine based on the cooling water temperature and the diesel engine speed includes the following steps: Construct a fan speed mapping table and a fan pulse width modulation duty cycle mapping table; wherein, the fan speed mapping table is a two-dimensional table, and the fan pulse width modulation duty cycle mapping table is a one-dimensional table; the rows of the fan speed mapping table represent the diesel engine speed, the columns of the fan speed mapping table represent the coolant temperature, and the fields of the fan speed mapping table represent the reference value of the fan speed; the rows of the fan pulse width modulation duty cycle mapping table represent the fan speed, and the fields of the fan pulse width modulation duty cycle mapping table represent the pulse width modulation duty cycle of the cooling fan; The fan speed is obtained by looking up the fan speed mapping table based on the cooling water temperature and the diesel engine speed. The pulse width modulation duty cycle of the cooling fan is obtained by looking up the fan pulse width modulation duty cycle mapping table based on the fan speed. The fan speed of the explosion-proof diesel engine is controlled by pulse width modulation (PWM) based on the PWM duty cycle of the cooling fan.

5. The composite cooling method for an explosion-proof diesel engine according to claim 1, characterized in that, Controlling the flow rate of the cooling water pump based on the cooling water temperature and the diesel engine speed includes the following steps: Construct a pump motor speed mapping table and a pump motor pulse width modulation duty cycle mapping table; wherein, the pump motor speed mapping table is a two-dimensional table, and the pump motor pulse width modulation duty cycle mapping table is a one-dimensional table; the rows of the pump motor speed mapping table represent the diesel engine speed, the columns of the pump motor speed mapping table represent the cooling water temperature, and the fields of the pump motor speed mapping table represent the reference value of the pump motor speed of the cooling water pump; the rows of the pump motor pulse width modulation duty cycle mapping table represent the pump motor speed, and the fields of the pump motor pulse width modulation duty cycle mapping table represent the pulse width modulation duty cycle of the pump motor of the cooling water pump. The pump motor speed is obtained by looking up the pump motor speed mapping table based on the cooling water temperature and the diesel engine speed. The pulse width modulation duty cycle of the pump motor is obtained by looking up the pulse width modulation duty cycle mapping table based on the pump motor speed. The flow rate of the cooling water pump is controlled by using a pulse width modulation method based on the pulse width modulation duty cycle of the pump motor.

6. The composite cooling method for an explosion-proof diesel engine according to claim 1, characterized in that, The turbine exhaust temperature of the explosion-proof diesel engine is controlled based on the diesel engine speed, the boost pressure, and the intake air temperature. The specific steps are as follows: The injection advance angle of the explosion-proof diesel engine is controlled according to the diesel engine speed, the boost pressure and the intake air temperature, so as to control the turbine exhaust temperature of the explosion-proof diesel engine.

7. The composite cooling method for an explosion-proof diesel engine according to claim 6, characterized in that, Controlling the injection advance angle of the explosion-proof diesel engine based on the diesel engine speed, the boost pressure, and the intake air temperature includes the following steps: Construct a basic exhaust temperature mapping table, a boost pressure exhaust temperature correction mapping table, and an intake air temperature exhaust temperature correction mapping table; wherein, the basic exhaust temperature mapping table, the boost pressure exhaust temperature correction mapping table, and the intake air temperature exhaust temperature correction mapping table are all two-dimensional tables; the rows of the basic exhaust temperature mapping table represent the diesel engine speed, the columns of the basic exhaust temperature mapping table represent the cyclic fuel injection quantity of the explosion-proof diesel engine, and the fields of the basic exhaust temperature mapping table represent the basic exhaust temperature value; the rows of the boost pressure exhaust temperature correction mapping table represent the diesel engine speed, the columns of the boost pressure exhaust temperature correction mapping table represent the boost pressure, and the fields of the boost pressure exhaust temperature correction mapping table represent the boost pressure exhaust temperature correction value; the rows of the intake air temperature exhaust temperature correction mapping table represent the speed of the explosion-proof diesel engine, the columns of the intake air temperature exhaust temperature correction mapping table represent the intake air temperature value of the explosion-proof diesel engine, and the fields of the intake air temperature exhaust temperature correction mapping table represent the intake air temperature exhaust temperature correction value. The basic exhaust temperature value is retrieved from the basic exhaust temperature mapping table based on the diesel engine speed and the cyclic fuel injection quantity. Based on the diesel engine speed and the boost pressure, the boost pressure exhaust temperature correction value is looked up in the boost pressure exhaust temperature correction mapping table; Based on the diesel engine speed and intake air temperature, look up the intake air temperature and exhaust air temperature correction value in the intake air temperature and exhaust air temperature correction mapping table; The turbine inlet exhaust temperature of the explosion-proof diesel engine is calculated based on the basic exhaust temperature value, the boost pressure exhaust temperature correction value, and the intake air temperature exhaust temperature correction value. The injection advance angle of the explosion-proof diesel engine is controlled based on the turbine exhaust temperature.

8. The composite cooling method for an explosion-proof diesel engine according to claim 1, characterized in that, The cooling fan is an electrically controlled fan, and the cooling water pump is an electrically controlled water pump.

9. A composite cooling system for an explosion-proof diesel engine, characterized in that, include: The data acquisition module is used to collect data on the cooling water temperature, engine speed, boost pressure, and intake air temperature of the explosion-proof diesel engine. The data processing module is used to determine a cooling control strategy based on the cooling water temperature; wherein the cooling control strategy includes a single control strategy, a dual-cooperative control strategy, and a triple-cooperative control strategy. The control module is used to control the fan speed of the cooling fan of the explosion-proof diesel engine according to the cooling water temperature and the diesel engine speed when the cooling control strategy is determined to be the single control strategy, so as to realize the cooling control of the explosion-proof diesel engine. The control module is also used to control the fan speed of the cooling fan of the explosion-proof diesel engine according to the cooling water temperature and the diesel engine speed when the cooling control strategy is determined to be the dual cooperative control strategy, and to control the flow rate of the cooling water pump according to the cooling water temperature and the diesel engine speed, so as to realize the cooling control of the explosion-proof diesel engine. The control module is also used to control the fan speed of the cooling fan of the explosion-proof diesel engine according to the cooling water temperature and the diesel engine speed when the cooling control strategy is determined to be a three-coordinated control strategy, and to control the flow rate of the cooling water pump according to the cooling water temperature and the diesel engine speed, and to control the turbine exhaust temperature of the explosion-proof diesel engine according to the diesel engine speed, the boost pressure and the intake air temperature, so as to achieve cooling control of the explosion-proof diesel engine.

10. An explosion-proof diesel engine, characterized in that, The system includes an explosion-proof diesel engine cooling system, wherein the explosion-proof diesel engine cooling system employs a composite cooling method for the explosion-proof diesel engine as described in any one of claims 1 to 8 to achieve cooling control of the explosion-proof diesel engine.

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