Composite cooling method and system for explosion-proof diesel engine

Abstract

The invention relates to a composite cooling method and system for an explosion-proof diesel engine. The method comprises the following steps that the cooling water temperature, the diesel engine rotating speed, the supercharging pressure and the air inlet temperature of the explosion-proof diesel engine are collected; determining a cooling control strategy according to the cooling water temperature; when the single control strategy is determined, the fan rotating speed of a cooling fan of the explosion-proof diesel engine is controlled, so that cooling control is achieved; when it is determined that the strategy is the double-cooperative control strategy, the fan rotating speed of a cooling fan of the explosion-proof diesel engine is controlled, and the flow of a cooling water pump is controlled, so that cooling control is achieved; when the three-cooperative control strategy is determined, the rotating speed of a fan, the flow of a cooling water pump and the turbine front exhaust temperature are controlled to achieve cooling control over the diesel engine; the problem that normal work of the explosion-proof diesel engine is affected due to engine flameout caused by high temperature during heavy-load long-distance large-gradient operation is solved, and the operation safety and stability of the explosion-proof diesel engine are improved.

Description

Technical Field

[0001] The invention relates to the technical field of cooling of explosion-proof diesel engines, and in particular to a composite cooling method and system of explosion-proof diesel engines. Background Art

[0002] According to the standard requirements, the surface temperature of the explosion-proof diesel engine for coal mines must be controlled below 150°C. Therefore, compared with ordinary ground diesel engines, not only the diesel engine body needs to be cooled, but also the high-temperature components outside the diesel engine, such as the exhaust manifold, supercharger, and exhaust tail pipe after the supercharger, need to be water-cooled to ensure that the temperature of any part of the diesel engine surface is below 150°C to meet the explosion-proof requirements. The cooling system of existing explosion-proof diesel engines often has high water temperature or even boiling in high-power applications, especially when running over long distances and large slopes, affecting the normal operation of the engine. The current solution is to use a single-circulation cooling system or add a second water pump to use a dual-circulation cooling system, which is difficult to meet the needs of efficient heat dissipation, especially when running over long distances and large slopes with heavy loads, resulting in high temperatures, causing the engine to stall, affecting 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 and high-slope operation, which causes engine flameout 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 technical problems is as follows:

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

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

[0007] Determine a cooling control strategy according to the cooling water temperature; wherein the cooling control strategy includes a single control strategy, a dual coordinated control strategy, and a triple coordinated 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 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, 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 realize 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 of the cooling water pump is controlled according to the cooling water temperature and the diesel engine speed, and the pre-turbine exhaust temperature of the explosion-proof diesel engine is controlled according to the diesel engine speed, the boost pressure and the intake temperature, so as to achieve cooling control of the explosion-proof diesel engine.

[0011] The beneficial effects of the present invention are as follows: cooling control of an explosion-proof diesel engine is achieved by adjusting the fan speed of a cooling fan under a single control strategy, cooling control of an explosion-proof diesel engine is achieved by adjusting the fan speed of a cooling fan and the flow rate of a cooling water pump under a dual coordinated control strategy, and cooling control of an explosion-proof diesel engine is achieved by adjusting the fan speed of a cooling fan and the flow rate of a cooling water pump under a triple coordinated control strategy while also controlling the turbine pre-exhaust temperature of the explosion-proof diesel engine; the cooling control of the diesel engine is diversified, and a suitable cooling control method can be selected according to the actual operating conditions of the explosion-proof diesel engine, thereby solving the problem of high temperature during heavy-load, long-distance, and large-slope operation, which causes the engine to stall and affects the normal operation of the explosion-proof diesel engine, and improving the operating safety and stability of the explosion-proof diesel engine.

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

[0013] Further, determining a cooling control strategy according to the cooling water temperature comprises the following steps:

[0014] When the cooling water temperature is less than or equal to a first preset threshold, determining that the cooling control strategy is the single control strategy;

[0015] When the cooling water temperature is greater than a first preset threshold and less than a second preset threshold, determining that the cooling control strategy is the dual coordinated 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-cooperative 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] Further, controlling the fan speed of the cooling fan of the explosion-proof diesel engine according to the cooling water temperature and the diesel engine speed comprises the following steps:

[0019] Constructing 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 cooling water temperature, and the domain of the fan speed mapping table represents 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 domain of the fan pulse width modulation duty cycle mapping table represents the pulse width modulation duty cycle of the cooling fan;

[0020] Obtaining the fan speed by searching the fan speed mapping table according to the cooling water temperature and the diesel engine speed;

[0021] Obtaining the pulse width modulation duty cycle of the cooling fan by searching the fan pulse width modulation duty cycle mapping table according to the fan speed;

[0022] A pulse width modulation method is adopted to control the fan speed of the cooling fan of the explosion-proof diesel engine according to the pulse width modulation duty ratio of the cooling fan.

[0023] Further, controlling the flow rate of the cooling water pump according to the cooling water temperature and the speed of the diesel engine comprises the following steps:

[0024] Constructing 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 domain of the pump motor speed mapping table represents 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 domain of the pump motor pulse width modulation duty cycle mapping table represents the pulse width modulation duty cycle of the pump motor of the cooling water pump;

[0025] Obtaining the pump motor speed by searching the pump motor speed mapping table according to the cooling water temperature and the diesel engine speed;

[0026] Obtaining the pulse width modulation duty cycle of the pump motor by searching the pulse width modulation duty cycle mapping table of the pump motor according to the pump motor speed;

[0027] A pulse width modulation method is adopted to control the flow rate of the cooling water pump according to the pulse width modulation duty cycle of the pump motor.

[0028] Further, the exhaust temperature before turbine of the explosion-proof diesel engine is controlled according to the diesel engine speed, the boost pressure and the intake air temperature, and 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 exhaust temperature before the turbine of the explosion-proof diesel engine.

[0030] Further, controlling the injection advance angle of the explosion-proof diesel engine according to the diesel engine speed, the boost pressure and the intake air temperature comprises the following steps:

[0031] Constructing 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 speed of the diesel engine, the columns of the basic exhaust temperature mapping table represent the cyclic injection amount of the explosion-proof diesel engine, and the domain of the basic exhaust temperature mapping table represents the basic exhaust temperature value; the rows of the boost pressure exhaust temperature correction mapping table represent the speed of the diesel engine, the columns of the boost pressure exhaust temperature correction mapping table represent the boost pressure, and the domain of the boost pressure exhaust temperature correction mapping table represents 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 domain of the intake air temperature exhaust temperature correction mapping table represents the intake air temperature correction value;

[0032] According to the diesel engine speed and the cyclic injection amount, the basic exhaust temperature value is searched in the basic exhaust temperature mapping table;

[0033] querying the boost pressure exhaust temperature correction value in the boost pressure exhaust temperature correction mapping table according to the diesel engine speed and the boost pressure;

[0034] According to the diesel engine speed and the intake temperature, the intake temperature and exhaust temperature correction value is searched in the intake temperature and exhaust temperature correction mapping table;

[0035] Calculating the pre-turbine exhaust temperature of the explosion-proof diesel engine according to 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 according to the pre-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] In order to solve the above technical problems, the present invention also provides a composite cooling system for an explosion-proof diesel engine, and its technical contents are as follows:

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

[0040] Data acquisition module, used to collect cooling water temperature, diesel engine speed, boost pressure and intake air temperature of explosion-proof diesel engines;

[0041] A data processing module, used to determine a cooling control strategy according to the cooling water temperature; wherein the cooling control strategy includes a single control strategy, a dual coordinated control strategy and a triple coordinated control strategy;

[0042] A control module, for controlling 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 achieve cooling control of the explosion-proof diesel engine;

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

[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, control the flow of the cooling water pump according to the cooling water temperature and the diesel engine speed, and control the pre-turbine exhaust temperature of the explosion-proof diesel engine according to the diesel engine speed, the boost pressure and the intake temperature when the cooling control strategy is determined to be the three-cooperative control strategy, so as to achieve cooling control of the explosion-proof diesel engine.

[0045] In order to solve the above technical problems, the present invention also provides an explosion-proof diesel engine, the technical contents of which are as follows:

[0046] An explosion-proof diesel engine comprises an explosion-proof diesel engine cooling system, wherein the explosion-proof diesel engine cooling system adopts the composite cooling method of the explosion-proof diesel engine to realize cooling control of the explosion-proof diesel engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a flowchart of a composite cooling method for an explosion-proof diesel engine in an embodiment of the present invention;

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

[0049] Figure 3 It is a schematic structural diagram of an explosion-proof diesel engine cooling system in an embodiment of the present invention. DETAILED DESCRIPTION

[0050] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used 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, comprising the following steps:

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

[0053] S2. Determine a cooling control strategy according to the cooling water temperature; wherein the cooling control strategy includes a single control strategy, a dual coordinated control strategy, and a triple coordinated control strategy;

[0054] Determining a cooling control strategy according to the cooling water temperature includes the following steps:

[0055] S201, when the cooling water temperature is less than or equal to a first preset threshold, determining that the cooling control strategy is the single control strategy;

[0056] S202, when the cooling water temperature is greater than a first preset threshold and less than a second preset threshold, determining that the cooling control strategy is the dual coordinated control strategy;

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

[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; wherein, the cooling fan is an electronically controlled fan, and the electronically controlled fan is preferably a pulse-controlled fan, that is, the fan motor of the cooling fan is a pulse-controlled motor. When the cooling water temperature is high, the fan speed is controlled to run at a higher speed, thereby increasing the wind speed flowing through the radiator and achieving a better cooling effect. Compared with the traditional mechanical cooling fan, the electronically 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, the present invention can regulate the cooling fan speed by the cooling water temperature, saving energy.

[0059] Controlling the fan speed of the cooling fan of the explosion-proof diesel engine according to the cooling water temperature and the diesel engine speed comprises the following steps:

[0060] S301. Construct a fan speed mapping table and a fan pulse width regulation duty cycle mapping table; wherein, the fan speed mapping table is as shown in Table 1, and 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 cooling water temperature, and the domain of the fan speed mapping table represents the reference value of the fan speed.

[0061] Table 1 Fan speed mapping table

[0062]

[0063]

[0064] Specifically, the fan pulse width regulation duty cycle mapping table is shown in Table 2, and the fan pulse width regulation duty cycle mapping table is a one-dimensional table; the row of the fan pulse width regulation duty cycle mapping table represents the fan speed, and the domain of the fan pulse width regulation duty cycle mapping table represents 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, obtaining the fan speed by querying the fan speed mapping table according to the cooling water temperature and the diesel engine speed; the fan speed is obtained by looking up the table, that is, the domain obtained by querying the reference values ​​of multiple fan speeds in the fan speed mapping table through the corresponding diesel engine speed and the cooling water temperature is the fan speed.

[0068] S303, obtaining the pulse width modulation duty cycle of the cooling fan by searching the fan pulse width modulation duty cycle mapping table according to the fan speed;

[0069] S304: Using a pulse width modulation method, the fan speed of the cooling fan of the explosion-proof diesel engine is controlled according to the pulse width modulation duty cycle of the cooling fan.

[0070] S4. When the cooling control strategy is determined to be the dual collaborative 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 of the cooling water pump is controlled according to the cooling water temperature and the diesel engine speed, so as to realize the cooling control of the explosion-proof diesel engine; wherein, the cooling water pump is an electronically controlled water pump, and the electronically controlled water pump is 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 according to the cooling water temperature and the diesel engine speed comprises the following steps:

[0072] S401, constructing 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 domain of the pump motor speed mapping table represents 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 domain of the pump motor pulse width modulation duty cycle mapping table represents the pulse width modulation duty cycle of the pump motor of the cooling water pump;

[0073] S402. Obtain the pump motor speed by querying the pump motor speed mapping table according to the cooling water temperature and the diesel engine speed; specifically, querying the reference values ​​corresponding to the cooling water temperature and the diesel engine speed from the multiple pump motor speed reference values ​​in the pump motor speed mapping table to obtain the pump motor speed.

[0074] S403, obtaining the pulse width modulation duty ratio of the pump motor by searching the pulse width modulation duty ratio mapping table of the pump motor according to the rotation speed of the pump motor;

[0075] S404: Using a pulse width modulation method, control the flow rate of the cooling water pump according to 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. After the electronic water pump is used in the embodiment of the present invention, the cooling water temperature and the water pump flow rate can be associated, and the cooling water flow rate can be controlled according to the cooling water temperature, thereby achieving a better cooling effect.

[0077] The electronic water pump can adjust the 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 just started, the demand for coolant is small, and the electronic water pump will run at a lower speed to save energy; when the engine is running at high speed or the load is large, the electronic water pump will increase the speed and increase the flow rate of coolant to ensure that the engine is fully cooled. At the same time, the controller can monitor the operating status of the water pump and issue an alarm when an abnormality is detected, which improves the reliability and safety of the cooling system.

[0078] The water pump flow is divided into three working states: large flow, medium flow and small flow. When the diesel engine is just started and the water temperature is lower than 60℃, the controller controls the water pump to enter the small flow working state. When the cooling water temperature is between 60℃ and 85℃, the controller controls the water pump to enter the medium flow working state. When the engine cooling water temperature exceeds 85℃, the controller controls the water pump to enter the large flow working 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 of the cooling water pump is controlled according to the cooling water temperature and the diesel engine speed, and the pre-turbine exhaust temperature of the explosion-proof diesel engine is controlled according to the diesel engine speed, the boost pressure and the intake temperature, so as to achieve cooling control of the explosion-proof diesel engine.

[0080] The exhaust temperature before turbine of the explosion-proof diesel engine is controlled according to the diesel engine speed, the boost pressure and the intake air temperature, and 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 exhaust temperature before the turbine of the explosion-proof diesel engine.

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

[0083] S501, constructing 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 speed of the diesel engine, the columns of the basic exhaust temperature mapping table represent the cyclic injection amount of the explosion-proof diesel engine, and the domain of the basic exhaust temperature mapping table represents the basic exhaust temperature value; the rows of the boost pressure exhaust temperature correction mapping table represent the speed of the diesel engine, the columns of the boost pressure exhaust temperature correction mapping table represent the boost pressure, and the domain of the boost pressure exhaust temperature correction mapping table represents 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 domain of the intake air temperature exhaust temperature correction mapping table represents the intake air temperature correction value;

[0084] S502, querying the basic exhaust temperature value in the basic exhaust temperature mapping table according to the diesel engine speed and the cyclic injection amount;

[0085] S503, querying the boost pressure exhaust temperature correction value in the boost pressure exhaust temperature correction mapping table according to the diesel engine speed and the boost pressure;

[0086] S504, querying the intake and exhaust temperature correction value in the intake and exhaust temperature correction mapping table according to the diesel engine speed and the intake temperature;

[0087] S505. Calculate the pre-turbocharger exhaust temperature of the explosion-proof diesel engine according to 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 pre-turbocharger exhaust temperature.

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

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

[0090] When the final turbine pre-exhaust temperature is greater than the limit exhaust temperature under the current working condition, 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 be greater than the injection advance angle increment limit;

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

[0092] When the exhaust temperature before the turbine is still greater than the preset exhaust temperature before the turbine after the injection pressure increases to the maximum value, the exhaust temperature is lowered by reducing the circulating injection amount, and the circulating injection amount is continuously reduced until the exhaust temperature before the turbine of the diesel engine does not exceed the limit.

[0093] The embodiment of the present invention realizes cooling control of the explosion-proof diesel engine by adjusting the fan speed of the cooling fan under a single control strategy, realizes cooling control of the explosion-proof diesel engine by adjusting the fan speed of the cooling fan and the flow rate of the cooling water pump under a dual coordinated control strategy, and realizes cooling control of the explosion-proof diesel engine by adjusting the fan speed of the cooling fan and the flow rate of the cooling water pump under a triple coordinated control strategy while also controlling the pre-turbine exhaust temperature of the explosion-proof diesel engine; the cooling control of the diesel engine is diversified, and a suitable cooling control method can be selected according to the actual operating conditions of the explosion-proof diesel engine, which solves the problem of high temperature during heavy-load, long-distance and large-slope operation, which causes engine stalling and affects the normal operation of the explosion-proof diesel engine, and improves the operating safety and stability of the explosion-proof diesel engine.

[0094] In some other embodiments, a composite cooling system for an explosion-proof diesel engine is also provided, and its technical contents are as follows:

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

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

[0097] A data processing module, used to determine a cooling control strategy according to the cooling water temperature; wherein the cooling control strategy includes a single control strategy, a dual coordinated control strategy and a triple coordinated control strategy;

[0098] A control module, for controlling 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 achieve 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 control the flow rate of the cooling water pump 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 coordinated 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, control the flow of the cooling water pump according to the cooling water temperature and the diesel engine speed, and control the pre-turbine exhaust temperature of the explosion-proof diesel engine according to the diesel engine speed, the boost pressure and the intake temperature when the cooling control strategy is determined to be the three-cooperative control strategy, so as to achieve cooling control of the explosion-proof diesel engine.

[0101] Among them, the data acquisition module, the data processing module and the control module can be functional modules in the control software system, or can be specific electronic control hardware modules or specific equipment.

[0102] In some other embodiments, an explosion-proof diesel engine is further provided, including an explosion-proof diesel engine cooling system, wherein the explosion-proof diesel engine cooling system adopts the above-mentioned composite cooling method of the explosion-proof diesel engine to realize 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 water jacket, a diesel engine cylinder head water jacket and a thermostat, etc. The cooling water circulates in the internal circulation system to cool the key components of the engine. The internal circulation system is divided into a small circulation and a large circulation. When the coolant temperature is lower than the opening temperature of the thermostat, it is a small circulation. The coolant flows through the first explosion-proof electronically controlled water pump, the diesel engine cylinder water jacket, the diesel engine cylinder head water jacket, the thermostat, and the first explosion-proof electronically controlled water pump in sequence, and does not flow through the radiator. When the coolant temperature is higher than the opening temperature of the thermostat, it is a large circulation. The large circulation is divided into two situations. One is that the thermostat is not fully opened, then the coolant flows through the first explosion-proof electronically controlled water pump, the diesel engine cylinder water jacket, the diesel engine cylinder head water jacket in sequence, and after flowing through the thermostat, a part of it returns to the radiator for cooling, and a part of it flows directly through the first explosion-proof electronically controlled water pump. The other is that the thermostat is fully opened, and the coolant flows through the first explosion-proof electronically controlled water pump, the diesel engine cylinder water jacket, the diesel engine cylinder head water jacket, and then flows through the thermostat and returns to the radiator for cooling. At the same time, an exhaust pipe is set at the high point of the diesel engine cylinder head where gas is easily generated to the expansion water tank to prevent gas 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, the second explosion-proof electronically controlled water pump, the water-cooled exhaust manifold, the explosion-proof water-cooled supercharger, the explosion-proof exhaust bellows, etc. The external circulation system is mainly responsible for cooling the high-temperature components through which the high-temperature exhaust of the engine flows. Considering that the external circulation system is mainly related to the exhaust temperature, in order to ensure the cooling effect, that is, when the circulating water enters the high-temperature components, the water temperature is low and more heat can be taken away, so the external circulation adopts a parallel circulation system. The coolant enters the water-cooled exhaust manifold, the explosion-proof water-cooled supercharger and the explosion-proof exhaust bellows in parallel after passing through the second water pump. After cooling these three high-temperature components, it returns to the radiator for cooling. At the same time, an exhaust pipe is set from the highest point of the water-cooled exhaust manifold and the explosion-proof water-cooled supercharger, which are components that are prone to generate gas, to the expansion water tank to prevent gas in the circulation system from affecting the coolant circulation effect.

[0105] In order to achieve complete independence of internal and external circulation and avoid the influence of the external circulation system on the internal circulation system, the radiator is divided into left and right sides and the left and right sides are completely separated, which effectively disperses the cooling load and improves the 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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A composite cooling method for an explosion-proof diesel engine, characterized in that: The steps include: Collect the cooling water temperature, diesel engine speed, boost pressure and intake air temperature of the explosion-proof diesel engine; Determine a cooling control strategy according to the cooling water temperature; wherein the cooling control strategy includes a single control strategy, a dual coordinated control strategy, and a triple coordinated 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 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, 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 realize 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 of the cooling water pump is controlled according to the cooling water temperature and the diesel engine speed, and the pre-turbine exhaust temperature of the explosion-proof diesel engine is controlled according to the diesel engine speed, the boost pressure and the intake 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 according to the cooling water temperature includes the following steps: When the cooling water temperature is less than or equal to a first preset threshold, determining that the cooling control strategy is the single control strategy; When the cooling water temperature is greater than a first preset threshold and less than a second preset threshold, determining that the cooling control strategy is the dual coordinated control strategy; When the cooling water temperature is greater than or equal to the second preset threshold, determining that the cooling control strategy is the three-coordinated control strategy; The first preset threshold is smaller 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 according to the cooling water temperature and the diesel engine speed comprises the following steps: Constructing 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 cooling water temperature, and the domain of the fan speed mapping table represents 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 domain of the fan pulse width modulation duty cycle mapping table represents the pulse width modulation duty cycle of the cooling fan; Obtaining the fan speed by searching the fan speed mapping table according to the cooling water temperature and the diesel engine speed; Obtaining the pulse width modulation duty cycle of the cooling fan by searching the fan pulse width modulation duty cycle mapping table according to the fan speed; A pulse width modulation method is adopted to control the fan speed of the cooling fan of the explosion-proof diesel engine according to the pulse width modulation duty ratio of the cooling fan.

5. The composite cooling method for explosion-proof diesel engine according to claim 1, characterized in that: Controlling the flow rate of the cooling water pump according to the cooling water temperature and the diesel engine speed comprises the following steps: Constructing 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 domain of the pump motor speed mapping table represents 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 domain of the pump motor pulse width modulation duty cycle mapping table represents the pulse width modulation duty cycle of the pump motor of the cooling water pump; Obtaining the pump motor speed by searching the pump motor speed mapping table according to the cooling water temperature and the diesel engine speed; Obtaining the pulse width modulation duty cycle of the pump motor by searching the pulse width modulation duty cycle mapping table of the pump motor according to the pump motor speed; A pulse width modulation method is adopted to control the flow rate of the cooling water pump according to 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 exhaust temperature before turbine of the explosion-proof diesel engine is controlled according to the diesel engine speed, the boost pressure and the intake air temperature, and 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 exhaust temperature before the turbine 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 according to the diesel engine speed, the boost pressure and the intake air temperature comprises the following steps: Constructing 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 speed of the diesel engine, the columns of the basic exhaust temperature mapping table represent the cyclic injection amount of the explosion-proof diesel engine, and the domain of the basic exhaust temperature mapping table represents the basic exhaust temperature value; the rows of the boost pressure exhaust temperature correction mapping table represent the speed of the diesel engine, the columns of the boost pressure exhaust temperature correction mapping table represent the boost pressure, and the domain of the boost pressure exhaust temperature correction mapping table represents 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 domain of the intake air temperature exhaust temperature correction mapping table represents the intake air temperature correction value; According to the diesel engine speed and the cyclic injection amount, the basic exhaust temperature value is searched in the basic exhaust temperature mapping table; querying the boost pressure exhaust temperature correction value in the boost pressure exhaust temperature correction mapping table according to the diesel engine speed and the boost pressure; According to the diesel engine speed and the intake temperature, the intake temperature and exhaust temperature correction value is searched in the intake temperature and exhaust temperature correction mapping table; Calculating the pre-turbine exhaust temperature of the explosion-proof diesel engine according to 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 according to the pre-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: Data acquisition module, used to collect cooling water temperature, diesel engine speed, boost pressure and intake air temperature of explosion-proof diesel engines; A data processing module, used to determine a cooling control strategy according to the cooling water temperature; wherein the cooling control strategy includes a single control strategy, a dual coordinated control strategy and a triple coordinated control strategy; A control module, for controlling 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 achieve cooling control of the explosion-proof diesel engine; The control module is also used for controlling 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 controlling the flow rate of the cooling water pump according to the cooling water temperature and the diesel engine speed, so as to realize cooling control of the explosion-proof diesel engine when the cooling control strategy is determined to be the dual coordinated control strategy; 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 of the cooling water pump according to the cooling water temperature and the diesel engine speed when the cooling control strategy is determined to be the three-cooperative control strategy, and to control the pre-turbine exhaust temperature of the explosion-proof diesel engine according to the diesel engine speed, the boost pressure and the intake temperature, so as to achieve cooling control of the explosion-proof diesel engine.

10. An explosion-proof diesel engine, characterized in that: It comprises an explosion-proof diesel engine cooling system, and the explosion-proof diesel engine cooling system adopts the composite cooling method of the explosion-proof diesel engine as claimed in any one of claims 1 to 8 to realize cooling control of the explosion-proof diesel engine.

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