Extremely cold working condition diesel oil preheating control system, control method and engineering machinery

Abstract

The invention discloses an extremely cold working condition diesel preheating control system, a control method and engineering machinery. The system comprises a diesel tank, a fuel heater, a heat exchanger and a conversion part, the fuel oil heater is connected with the diesel oil tank to form a closed-loop diesel oil circulation channel I, and diesel oil in the diesel oil tank is used as fuel for heating of the fuel oil heater; on one hand, the heat exchanger is connected with the fuel heater and the engine to form a closed-loop cooling liquid circulation channel; on the other hand, a diesel circulation channel II is formed by connecting with the diesel tank; the conversion part is connected in the diesel oil circulation channel II located at the outlet end of the heat exchanger, the conversion part, the engine and the diesel oil tank form a diesel oil circulation channel III, and diesel oil in the diesel oil tank is used as fuel for rotation of the engine. The working mode that high-grade diesel oil is used under the extremely cold working condition and different oil tanks are switched back and forth is avoided, and the problem that the combustion efficiency is low due to the low diesel oil temperature under the extremely cold weather is solved.

Description

Technical Field

[0001] The invention relates to a diesel preheating control system and a control method under extremely cold working conditions, and belongs to the technical field of engineering machinery. Background Art

[0002] For mining excavators, diesel is not easy to burn in extremely cold weather, and the diesel engine is difficult to start or cannot start due to the low diesel temperature. The low diesel temperature will reduce the atomization efficiency of the injector, which in turn leads to a decrease in engine combustion efficiency. The traditional solution is to use a heater to heat the diesel directly in the diesel tank, or to add an auxiliary fuel tank to first use higher-grade diesel to warm up the engine, and then switch to the diesel in the main tank after the engine is working normally.

[0003] Heating diesel directly in the diesel tank poses a safety hazard, and using an electric heater carries the risk of electric leakage; using hot coolant for heating may result in water leakage; and using two diesel tanks for fuel supply requires switching between different diesel tanks for each start, which is cumbersome. In addition, mixing different oils will reduce the service life of the engine, making the system complex and unreliable. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the present invention provides a diesel preheating control system and control method for extremely cold working conditions, which avoids the use of high-grade diesel and the switching back and forth of different fuel tanks under extremely cold working conditions, and solves the problem of low combustion efficiency caused by low diesel temperature under extremely cold weather.

[0005] The present invention is achieved by the following technical solutions:

[0006] In a first aspect, the present invention provides a diesel preheating control system for extremely cold conditions, comprising:

[0007] Diesel tank, used for storing diesel;

[0008] A fuel heater connected to the diesel tank to form a closed-loop diesel flow channel I, wherein the diesel in the diesel tank is used as fuel for heating by the fuel heater;

[0009] The heat exchanger is connected to the fuel heater and the engine on one hand to form a closed-loop coolant circulation channel, and the fuel heater heats the coolant; on the other hand, it is connected to the diesel tank to form a diesel circulation channel II, and the heated coolant exchanges heat with diesel below a preset temperature T1 in the heat exchanger;

[0010] The conversion component is connected to the diesel flow channel II at the outlet end of the heat exchanger. The conversion component also forms a diesel flow channel III with the engine and the diesel tank. The diesel in the diesel tank is used as fuel for the engine to rotate. The conversion component is constructed as follows:

[0011] When the temperature t2 of the diesel flowing out of the heat exchanger is lower than the engine diesel combustion setting temperature T2, the conversion component opens the diesel flow channel II and closes the diesel flow channel III to circulate and heat the diesel;

[0012] When the temperature t2 of the diesel flowing out of the heat exchanger is greater than the engine diesel combustion setting temperature T2, the conversion component simultaneously opens the diesel flow channel II and the diesel flow channel III, on the one hand continuing to preheat the diesel, on the other hand entering the engine for combustion;

[0013] When the temperature t2 of the diesel flowing out of the heat exchanger is greater than the engine diesel combustion set temperature T3 and T2<T3, the conversion component closes the diesel flow channel II to the diesel tank and continues to open the diesel flow channel III.

[0014] In some embodiments, the oil outlet of the diesel tank is connected to a fuel pump for inputting the diesel in the diesel tank into the fuel heater and the heat exchanger; the coolant circulation channel is connected to a water pump for circulating the coolant; the diesel circulation channel I is connected to an electromagnetic valve; the electromagnetic valve, fuel heater, and water pump are all connected to the vehicle controller. When the diesel temperature t1 in the diesel tank is lower than the temperature T1, the vehicle controller opens the electromagnetic valve, fuel heater, and water pump; when the diesel temperature t2 is greater than the temperature T3, the vehicle controller closes the electromagnetic valve, fuel heater, and water pump.

[0015] In some embodiments, a temperature sensor I is installed on the diesel tank, and the temperature sensor I is connected to the vehicle controller for transmitting the detected diesel temperature t1 to the vehicle controller; a temperature sensor II is connected to the diesel circulation channel II located between the conversion component and the heat exchanger, and the temperature sensor II is connected to the vehicle controller for transmitting the detected diesel temperature t2 to the vehicle controller.

[0016] In some embodiments, the conversion component is an electromagnetic three-way valve, which is connected to the vehicle controller to control the on-off of the pipeline of the electromagnetic three-way valve; or, the conversion component is composed of a three-way valve and two electromagnetic switches, and the three-way valve is connected at the node of the diesel circulation channel II and the diesel circulation channel III, one of the electromagnetic switches is connected between the three-way valve and the diesel tank, and the other electromagnetic switch is connected between the three-way valve and the engine, and the two electromagnetic switches are respectively connected to the vehicle controller to control the on-off of the pipeline of the electromagnetic switch.

[0017] In some embodiments, a fuel filter is connected between the conversion component and the oil inlet of the engine; and / or an oil-water separator is connected to the oil outlet of the diesel tank.

[0018] In some embodiments, a fuel radiator for dissipating heat from diesel is provided in the oil return line between the engine and the diesel tank.

[0019] In some embodiments, a flow control valve I and a flow control valve II are further provided in the oil return line between the engine and the diesel tank. The flow control valve I is connected in series with the fuel radiator, and the flow control valve II is connected in parallel with the flow control valve I and the fuel radiator. The flow control valve I and the flow control valve II are respectively connected to the vehicle controller. The flow control valve I and the flow control valve II are constructed as follows:

[0020] When the return oil temperature t3 of the engine is lower than the return oil set temperature T4 during normal operation, the vehicle controller controls the opening of the flow control valve II to 100% and the opening of the flow control valve I to 0%;

[0021] When the return oil temperature t3 of the engine is higher than the return oil set temperature T5 during normal operation, the vehicle controller controls the opening of the flow control valve II to 0% and the opening of the flow control valve I to 100%;

[0022] When the return oil temperature during normal engine operation is T4<t3≤T5, the vehicle controller controls the opening of flow control valve II to X, and the opening of flow control valve I to 1-X, where X=(t3-T4) / (T5-T4)x100%.

[0023] In some embodiments, a temperature sensor III is further provided in the oil return line between the engine and the diesel tank. The temperature sensor III is connected to the vehicle controller and is used to transmit the detected diesel temperature t3 to the vehicle controller.

[0024] In a second aspect, the present invention provides a method for controlling diesel preheating under extreme cold conditions:

[0025] After the vehicle is powered on, the fuel pump starts working. The temperature sensor I in the diesel tank detects that the diesel temperature t1 is lower than the set temperature T1. The vehicle controller turns on the solenoid valve, fuel heater, and water pump. After the solenoid valve is turned on, the fuel pump pumps the low-temperature diesel into the fuel heater, where it burns and heats the diesel.

[0026] The water pump pumps the coolant in the engine into the fuel heater for heat exchange. The heated coolant passes through the heat exchanger and then flows back to the engine, thus realizing the coolant circulation.

[0027] When the temperature sensor II detects that the temperature t2 of the diesel flowing out of the heat exchanger is lower than the diesel combustion set temperature T2, the vehicle controller controls the conversion component to close the oil inlet pipeline and open the oil return pipeline. The diesel pumped into the heat exchanger by the fuel pump flows directly back to the diesel tank to continue the diesel circulation preheating.

[0028] When the temperature sensor II detects that the diesel temperature is T2<t2≤T3, the vehicle controller controls the conversion component to open the oil inlet and return lines. The diesel pumped into the heat exchanger by the fuel pump enters the engine for combustion, and the engine operates normally; the fuel heater continues to work, and the heat exchanger continues to preheat the diesel;

[0029] When the temperature sensor II detects that the diesel temperature t2 is higher than the diesel combustion set temperature T3, the vehicle controller controls the conversion component to close the return oil pipeline and the solenoid valve, fuel heater, and water pump. The diesel preheating ends and the engine continues to work.

[0030] In some embodiments, the engine operates normally, and the return oil returns to the diesel tank through the return oil pipeline, and the return oil pipeline is provided with a temperature sensor III, a flow control valve I, a flow control valve II and a fuel radiator;

[0031] When the temperature sensor III detects that the diesel temperature t3 is lower than the return oil setting temperature T4, the vehicle controller controls the flow control valve II to open 100%, the flow control valve I to open 0%, and the diesel returns directly to the diesel tank through the flow control valve II;

[0032] When the temperature sensor III detects that the diesel temperature t3 is higher than the return oil set temperature T5, the vehicle controller controls the flow control valve II to open 0% and the flow control valve I to open 100%. The diesel passes through the flow control valve I to the fuel radiator and then returns to the diesel tank after heat dissipation.

[0033] When temperature sensor III detects that the diesel temperature is T4<t3≤T5, the vehicle controller controls the opening of flow control valve II to X, and the opening of flow control valve I is 1-X, X=(t3-T4) / (T5-T4)x100%; as the diesel temperature rises, the opening of flow control valve I increases, and the corresponding opening of flow control valve II decreases.

[0034] In a third aspect, the present invention provides an engineering machinery including the above-mentioned extreme cold conditions diesel preheating control system.

[0035] Beneficial effects of the present invention:

[0036] 1. Ensure that the engine works efficiently in extremely cold conditions: The present invention uses a heater to preheat the diesel through heat exchange, and accurately controls the engine's oil inlet and return temperatures through a temperature sensor and a flow control valve, ensuring that the diesel temperature is always within the engine's optimal required temperature range. This avoids the problem of low engine combustion efficiency caused by low diesel temperature in extremely cold weather and the efficiency of the fuel injector atomizing the diesel, thereby ensuring efficient engine operation.

[0037] 2. Improved safety of the preheating system: The fuel heater is changed from the traditional method of directly heating diesel through the diesel tank to heating the coolant, and then the high-temperature coolant and low-temperature diesel are heat-exchanged in a heat exchanger outside the diesel tank, avoiding the safety hazards of water leakage and electric leakage caused by heating diesel from the diesel tank.

[0038] 3. Improved reliability and service life of the preheating system: Compared with other heating systems that require switching between different fuel tanks, which is cumbersome to operate, and mixing different oils will reduce the service life of the engine, and the system is complex and unreliable; the present invention only uses one type of diesel to work, ensuring the singleness of the oil and improving the reliability and service life of the heating system.

[0039] 4. Improved operational convenience and automation of the preheating system: The operator only needs to turn on the power normally, and the preheating system can preheat the diesel by controlling the flow control valve and temperature sensor and keep the diesel oil temperature within the temperature range required by the engine, reducing the frequency of manual control and improving the operational convenience and automation of the preheating system. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings, as part of this disclosure, are intended to provide a further understanding of the disclosure. The exemplary embodiments of the disclosure and their descriptions are intended to explain the disclosure and do not constitute undue limitations thereon. Obviously, the drawings described below are merely examples, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0041] In the attached figure:

[0042] Figure 1 The component connection principle of the diesel preheating control system for extreme cold working conditions of the present invention Figure 1 ;

[0043] Figure 2 The logic of the diesel preheating control method for extremely cold working conditions of the present invention is as follows Figure 1 ;

[0044] Figure 3 The electrical control principle of the diesel preheating control system in extreme cold conditions of the present invention Figure 1 ;

[0045] Figure 4 The component connection principle of the diesel preheating control system for extreme cold working conditions of the present invention Figure 2 ;

[0046] Figure 5 The logic of the diesel preheating control method for extremely cold working conditions of the present invention is as follows Figure 2 ;

[0047] Figure 6The electrical control principle of the diesel preheating control system in extreme cold conditions of the present invention Figure 2 ;

[0048] Figure 7 The electrical control principle of the diesel preheating control system in extreme cold conditions of the present invention Figure 3 .

[0049] Figure symbols: temperature sensor I1, diesel tank 2, oil-water separator 3, fuel pump 4, three-way valve 5, solenoid valve 6, fuel pump 7, fuel heater 8, water pump 9, heat exchanger 10, temperature sensor II 11, solenoid three-way valve 12, fuel filter 13, engine 14, fuel radiator 15, flow control valve I 16, three-way valve 17, temperature sensor III 18, flow control valve II 19, solenoid switch 20, solenoid switch 21, three-way valve 22.

[0050] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but rather to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0052] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; and direct or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0053] like Figure 1 、 Figure 2 、 Figure 3As shown, a diesel preheating control system for extremely cold working conditions includes a diesel tank 2, a fuel heater 8, a heat exchanger 10 and a conversion component; the diesel tank 2 is used to store diesel; the fuel heater 8 is connected to the diesel tank 2 to form a closed-loop diesel circulation channel I (diesel inlet and return pipeline), and the diesel in the diesel tank 2 is used as fuel for heating by the fuel heater 8; the heat exchanger 10 is connected to the fuel heater 8 and the engine 14 on one hand to form a closed-loop coolant circulation channel (coolant heating circulation pipeline), and the fuel heater 8 heats the coolant; on the other hand, it is connected to the diesel tank 2 to form a diesel circulation channel II (diesel inlet, heating and return pipeline), and the heated coolant and diesel below a preset temperature T1 are heat-exchanged in the heat exchanger 10; the conversion component is connected to the diesel circulation channel II located at the outlet end of the heat exchanger 10, and the conversion component also forms a diesel circulation channel III (engine inlet and return pipeline) with the engine 14 and the diesel tank 2, and the diesel in the diesel tank 2 is used as fuel for the engine 14 to rotate; the conversion component is constructed as follows:

[0054] When the temperature t2 of the diesel flowing out of the heat exchanger 10 is lower than the engine diesel combustion setting temperature T2, the conversion component opens the diesel flow channel II and closes the diesel flow channel III to circulate and heat the diesel;

[0055] When the temperature t2 of the diesel flowing out of the heat exchanger 10 is greater than the engine diesel combustion set temperature T2, the conversion component opens the diesel flow channel II and the diesel flow channel III at the same time, on the one hand continuing to preheat the diesel, on the other hand entering the engine 14 for combustion;

[0056] When the temperature t2 of the diesel flowing out of the heat exchanger 10 is greater than the engine diesel combustion set temperature T3 and T2<T3, the switching component closes the diesel flow channel II to the diesel tank and continues to open the diesel flow channel III.

[0057] From the above, it can be seen that the present invention provides a diesel preheating control system for extremely cold working conditions, which avoids the use of high-grade diesel and the switching back and forth of different fuel tanks under extremely cold working conditions, and solves the problem of low combustion efficiency caused by low diesel temperature in extremely cold weather.

[0058] For further solutions, please refer to Figure 1As shown, the oil outlet of the diesel tank 2 is connected to a fuel pump 4 for inputting the diesel in the diesel tank 2 into the fuel heater 8 and the heat exchanger 10; the coolant circulation channel is connected to a water pump 9 for circulating the coolant; the diesel circulation channel I is connected to an electromagnetic valve 6; the electromagnetic valve 6, the fuel heater 8, and the water pump 9 are all connected to the vehicle controller. When the diesel temperature t1 in the diesel tank 2 is lower than the temperature T1, the vehicle controller opens the electromagnetic valve 6, the fuel heater 8, and the water pump 9; when the diesel temperature t2 is greater than the temperature T3, the vehicle controller closes the electromagnetic valve 6, the fuel heater 8, and the water pump 9.

[0059] It should be noted that Figure 1 The fuel heater 8 used in the present invention is equipped with a water pump 9 and a fuel pump 7. Of course, in actual use, it is possible to not have the fuel pump 7 and only choose a fuel heater 8 with a water pump 9. Alternatively, it is possible to choose a fuel heater 8 with only heating function and purchase a water pump 9 separately. Therefore, the type of fuel heater 8 can be selected according to actual needs.

[0060] For further solutions, please refer to Figure 1 、 Figure 3 As shown, a temperature sensor Ⅰ1 is installed on the diesel tank 2, and the temperature sensor Ⅰ1 is connected to the vehicle controller for transmitting the detected diesel temperature t1 to the vehicle controller; a temperature sensor Ⅱ11 is connected to the diesel flow channel Ⅱ located between the conversion component and the heat exchanger 10, and the temperature sensor Ⅱ11 is connected to the vehicle controller for transmitting the detected diesel temperature t2 to the vehicle controller.

[0061] For further solutions, please refer to Figure 1 As shown, a fuel filter 13 is connected between the conversion component and the oil inlet of the engine; and an oil-water separator 3 is connected to the oil outlet of the diesel tank 2.

[0062] It should be noted that a three-way valve 5 (always in an open state) or a three-way joint is connected at the node of the electromagnetic valve 6, the heat exchanger 10 and the fuel pump 4.

[0063] The specific structure of the above-mentioned conversion component is further described below.

[0064] like Figure 1 、 Figure 3 As shown, the conversion component is an electromagnetic three-way valve 12, which is connected to the vehicle controller to control the on-off of the pipeline of the electromagnetic three-way valve 12.

[0065] Or, as Figure 7As shown, the conversion component consists of a three-way valve 22 (or a three-way connector) and two electromagnetic switches 20 and 21. The three-way valve 22 is connected at the node of the diesel circulation channel II and the diesel circulation channel III. One of the electromagnetic switches 21 is connected between the three-way valve 22 and the diesel tank 2, and the other electromagnetic switch 20 is connected between the three-way valve 22 and the engine 14. The two electromagnetic switches 20 and 21 are respectively connected to the vehicle controller to control the on-off of the electromagnetic switch pipeline.

[0066] For further solutions, please refer to Figure 1 As shown, a fuel radiator 15 for dissipating heat from diesel is provided in the oil return line between the engine 14 and the diesel tank 2 .

[0067] continue Figure 1 、 Figure 2 、 Figure 3 As shown, the working principle of the fuel heater is as follows: under extremely cold working conditions, the temperature sensor I1 in the diesel tank 2 detects that the diesel temperature t1 is lower than the set temperature T1, the solenoid valve 6 is in the open state, and the fuel heater 6 with the fuel pump 7 and the water pump 9 starts to work. The fuel pump 7 (the fuel pump 7 can be omitted and can be directly used by the fuel pump 4) draws the low-temperature diesel into the heater and sprays it into the combustion chamber through the nozzle for ignition. The vehicle controller controls the heater to start working, and the water pump 9 draws the coolant in the engine 14 into the heater heat exchange chamber to start heat exchange, and then returns to the engine 14 to form a coolant circulation. A heat exchanger 10 is provided in the high-temperature coolant circuit.

[0068] continue Figure 1 、 Figure 2 、 Figure 3 As shown, after the vehicle is powered on, the fuel pump 4 starts working, and the low-temperature diesel in the diesel tank 2 is sucked into the oil-water separator 3 through the fuel pump 4 for filtration, and then passes through the three-way valve 5 to reach the heat exchanger 10 provided in the above-mentioned high-temperature coolant pipeline. The low-temperature diesel and the high-temperature coolant exchange heat in the heat exchanger 10 to preheat the low-temperature diesel.

[0069] A temperature sensor II 11 is provided in the diesel pipeline after preheating by the above-mentioned heat exchanger 10. When the temperature sensor II 11 detects that the diesel temperature t2 is lower than the diesel combustion set temperature T2, the temperature signal is fed back to the vehicle controller to control the electromagnetic three-way valve 12 to close the oil inlet pipeline and open the oil return pipeline. The diesel returns directly to the diesel tank 2 to continue the diesel circulation preheating.

[0070] When temperature sensor II 11 detects the diesel temperature (T2 < t2 ≤ T3), it feeds the temperature signal back to the vehicle controller, controlling electromagnetic three-way valve 12 to open the fuel inlet and return lines. The engine meets the starting conditions and begins ignition. After being filtered by fuel filter 13, the diesel enters engine 14 for combustion, and engine 14 operates normally. Fuel heater 8 continues to operate, and heat exchanger 10 continues to preheat the diesel.

[0071] When the temperature sensor II 11 detects that the diesel temperature is higher than the diesel combustion set temperature T3, the temperature signal is fed back to the vehicle controller, the electromagnetic three-way valve 12 is controlled to close the return oil pipeline, the electromagnetic valve 6 is controlled to close, and at the same time the fuel pump 7 and the water pump 9 are powered off and stop working. The vehicle controller controls the fuel heater 8 to stop working, the diesel preheating ends, and the engine continues to work.

[0072] The engine 14 operates normally, and the return oil returns to the diesel tank 2 through the return oil pipeline. The return oil pipeline is provided with a fuel radiator 15. The diesel returns to the diesel tank 2 after being cooled by the fuel radiator.

[0073] like Figure 4 、 Figure 5 、 Figure 6 As shown, the present invention further describes the oil return pipeline as follows:

[0074] A flow control valve I16 and a flow control valve II19 are also provided in the return oil pipeline between the engine 14 and the diesel tank 2. The flow control valve I16 is connected in series with the fuel radiator 15, and the flow control valve II19 is connected in parallel with the flow control valve I16 and the fuel radiator 15. The flow control valve I16 and the flow control valve II19 are respectively connected to the vehicle controller; a temperature sensor III18 is also provided in the return oil pipeline between the engine 14 and the diesel tank 2. The temperature sensor III18 is connected to the vehicle controller and is used to transmit the detected diesel temperature t3 to the vehicle controller.

[0075] It should be noted that a three-way valve 17 (always in an open state) or a three-way joint is connected at the node of the flow control valve I 16 , the flow control valve II 19 and the engine 14 .

[0076] Continue to refer to Figure 5 As shown, when the temperature sensor III 18 detects that the diesel temperature t3 is lower than the return oil setting temperature T4, the vehicle controller controls the flow control valve II 19 to open, the flow control valve 16 opening is 0%, the flow control valve II 19 opening is 100%, and the diesel returns directly to the diesel tank 2 through the flow control valve II 19 circuit;

[0077] When the temperature sensor III 18 detects that the diesel temperature t3 is higher than the return oil set temperature T5, the vehicle controller controls the flow control valve II 19 to open 0% and the flow control valve I 16 to open 100%. The diesel passes through the flow control valve I 16 circuit to the fuel radiator 15, and after the diesel is cooled, it returns to the diesel tank 2.

[0078] When the temperature sensor III 18 detects that the diesel temperature is T4<t3≤T5, the controller controls the opening of the flow control valve II 19 to X, and the opening of the flow control valve I 16 is 1-X, X=(t3-T4) / (T5-T4)x100%. The diesel reaches the fuel radiator 15 through the flow control valve I 16 circuit, and the diesel returns to the diesel tank 2 after heat dissipation. The other part returns to the diesel tank 2 after passing through the flow control valve II 19; when the temperature sensor III 18 detects that the diesel temperature is T4<t3≤T5, as the diesel temperature rises, the opening of the flow control valve I 16 increases, and the corresponding opening of the flow control valve II 19 decreases.

[0079] In summary, the present invention provides a diesel preheating control system and control method for extremely cold conditions, which achieves the following functions and effects:

[0080] 1. Ensure that the engine works efficiently in extremely cold conditions: The present invention uses a heater to preheat the diesel through heat exchange, and accurately controls the engine's oil inlet and return temperatures through a temperature sensor and a flow control valve, ensuring that the diesel temperature is always within the engine's optimal required temperature range. This avoids the problem of low engine combustion efficiency caused by low diesel temperature in extremely cold weather and the efficiency of the fuel injector atomizing the diesel, thereby ensuring efficient engine operation.

[0081] 2. Improved safety of the preheating system: The fuel heater is changed from the traditional method of directly heating diesel through the diesel tank to heating the coolant, and then the high-temperature coolant and low-temperature diesel are heat-exchanged in a heat exchanger outside the diesel tank, avoiding the safety hazards of water leakage and electric leakage caused by heating diesel from the diesel tank.

[0082] 3. Improved reliability and service life of the preheating system: Compared with other heating systems that require switching between different fuel tanks, which is cumbersome to operate, and mixing different oils will reduce the service life of the engine, and the system is complex and unreliable; the present invention only uses one type of diesel to work, ensuring the singleness of the oil and improving the reliability and service life of the heating system.

[0083] 4. Improved operational convenience and automation of the preheating system: The operator only needs to turn on the power normally, and the preheating system can preheat the diesel by controlling the flow control valve and temperature sensor and keep the diesel oil temperature within the temperature range required by the engine, reducing the frequency of manual control and improving the operational convenience and automation of the preheating system.

[0084] The engineering machinery provided by the present invention is described below. The engineering machinery described below and the extremely cold working condition diesel preheating control system described above can be referred to in correspondence with each other.

[0085] The present invention provides an engineering machinery, which may include the extremely cold working condition diesel preheating control system as described in any one of the above embodiments.

[0086] The beneficial effects achieved by the engineering machinery provided by the present invention are consistent with the beneficial effects achieved by the extremely cold working condition diesel preheating control system provided by the present invention, and will not be described in detail here.

[0087] It should be noted that the above-mentioned engineering machinery may be a mining excavator.

[0088] In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0089] Furthermore, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, combinations of features from different embodiments are also intended to fall within the scope of protection of the present invention and form different embodiments. For example, in the above embodiments, those skilled in the art will be able to use them in combination based on the known technical solutions and the technical problems to be solved by this application.

[0090] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with the present invention can make some changes or modifications to equivalent embodiments using the above-mentioned technical contents without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the solution of the present invention.

Claims

1. A diesel preheating control system for extremely cold working conditions, characterized in that: include: Diesel tank, used for storing diesel; A fuel heater connected to the diesel tank to form a closed-loop diesel flow channel I, wherein the diesel in the diesel tank is used as fuel for heating by the fuel heater; The heat exchanger is connected to the fuel heater and the engine on one hand to form a closed-loop coolant circulation channel, and the fuel heater heats the coolant; on the other hand, it is connected to the diesel tank to form a diesel circulation channel II, and the heated coolant exchanges heat with diesel below a preset temperature T1 in the heat exchanger; The conversion component is connected to the diesel flow channel II at the outlet end of the heat exchanger. The conversion component also forms a diesel flow channel III with the engine and the diesel tank. The diesel in the diesel tank is used as fuel for the engine to rotate. The conversion component is constructed as follows: When the temperature t2 of the diesel flowing out of the heat exchanger is lower than the engine diesel combustion setting temperature T2, the conversion component opens the diesel flow channel II and closes the diesel flow channel III to circulate and heat the diesel; When the temperature t2 of the diesel flowing out of the heat exchanger is greater than the engine diesel combustion setting temperature T2, the conversion component simultaneously opens the diesel flow channel II and the diesel flow channel III, on the one hand continuing to preheat the diesel, on the other hand entering the engine for combustion; When the temperature t2 of the diesel flowing out of the heat exchanger is greater than the engine diesel combustion set temperature T3 and T2<T3, the conversion component closes the diesel flow channel II to the diesel tank and continues to open the diesel flow channel III.

2. The extremely cold diesel preheating control system according to claim 1, characterized in that: The oil outlet of the diesel tank is connected to a fuel pump for inputting the diesel in the diesel tank into the fuel heater and the heat exchanger; A water pump is connected to the coolant circulation channel for circulating the coolant; The diesel flow channel I is connected to an electromagnetic valve; The solenoid valve, fuel heater and water pump are all connected to the vehicle controller. When the diesel temperature t1 in the diesel tank is lower than temperature T1, the vehicle controller opens the solenoid valve, fuel heater and water pump; when the diesel temperature t2 is greater than temperature T3, the vehicle controller closes the solenoid valve, fuel heater and water pump.

3. The diesel preheating control system for extremely cold conditions according to claim 2, characterized in that: The diesel tank is equipped with a temperature sensor I, which is connected to the vehicle controller and is used to transmit the detected diesel temperature t1 to the vehicle controller; A temperature sensor II is connected to the diesel flow channel II between the conversion component and the heat exchanger. The temperature sensor II is connected to the vehicle controller and is used to transmit the detected diesel temperature t2 to the vehicle controller.

4. The diesel preheating control system for extreme cold conditions according to claim 1, characterized in that: The conversion component is an electromagnetic three-way valve, which is connected to the vehicle controller to control the on-off of the pipeline of the electromagnetic three-way valve; or, The conversion component consists of a three-way valve and two electromagnetic switches. The three-way valve is connected at the node of diesel circulation channel II and diesel circulation channel III. One electromagnetic switch is connected between the three-way valve and the diesel tank, and the other electromagnetic switch is connected between the three-way valve and the engine. The two electromagnetic switches are respectively connected to the vehicle controller to control the on-off of the electromagnetic switch pipeline.

5. The diesel preheating control system for extreme cold conditions according to claim 1, characterized in that: A fuel filter is connected between the conversion component and the fuel inlet of the engine; and / or, An oil-water separator is connected to the oil outlet of the diesel tank.

6. The diesel preheating control system for extreme cold conditions according to any one of claims 1 to 5, characterized in that: A fuel radiator for dissipating heat from diesel is provided in the oil return pipeline between the engine and the diesel tank.

7. The extremely cold diesel preheating control system according to claim 6, characterized in that: A flow control valve I and a flow control valve II are further provided in the oil return line between the engine and the diesel tank. The flow control valve I is connected in series with the fuel radiator, and the flow control valve II is connected in parallel with the flow control valve I and the fuel radiator. The flow control valve I and the flow control valve II are respectively connected to the vehicle controller. The flow control valve I and the flow control valve II are constructed as follows: When the return oil temperature t3 of the engine is lower than the return oil set temperature T4 during normal operation, the vehicle controller controls the opening of the flow control valve II to 100% and the opening of the flow control valve I to 0%; When the return oil temperature t3 of the engine is higher than the return oil set temperature T5 during normal operation, the vehicle controller controls the opening of the flow control valve II to 0% and the opening of the flow control valve I to 100%; When the return oil temperature during normal engine operation is T4<t3≤T5, the vehicle controller controls the opening of flow control valve II to X, and the opening of flow control valve I to 1-X, where X=(t3-T4) / (T5-T4)x100%.

8. The extremely cold diesel preheating control system according to claim 7, characterized in that: A temperature sensor III is also provided in the oil return line between the engine and the diesel tank. The temperature sensor III is connected to the vehicle controller and is used to transmit the detected diesel temperature t3 to the vehicle controller.

9. A diesel preheating control method for extremely cold conditions, characterized by: After the vehicle is powered on, the fuel pump starts working. The temperature sensor I in the diesel tank detects that the diesel temperature t1 is lower than the set temperature T1. The vehicle controller turns on the solenoid valve, fuel heater, and water pump. After the solenoid valve is turned on, the fuel pump pumps the low-temperature diesel into the fuel heater, where it burns and heats the diesel. The water pump pumps the coolant in the engine into the fuel heater for heat exchange. The heated coolant passes through the heat exchanger and then flows back to the engine, thus realizing the coolant circulation. When the temperature sensor II detects that the temperature t2 of the diesel flowing out of the heat exchanger is lower than the diesel combustion set temperature T2, the vehicle controller controls the conversion component to close the oil inlet pipeline and open the oil return pipeline. The diesel pumped into the heat exchanger by the fuel pump flows directly back to the diesel tank to continue the diesel circulation preheating. When the temperature sensor II detects that the diesel temperature is T2<t2≤T3, the vehicle controller controls the conversion component to open the oil inlet and return lines. The diesel pumped into the heat exchanger by the fuel pump enters the engine for combustion, and the engine operates normally; the fuel heater continues to work, and the heat exchanger continues to preheat the diesel; When the temperature sensor II detects that the diesel temperature t2 is higher than the diesel combustion set temperature T3, the vehicle controller controls the conversion component to close the return oil pipeline and the solenoid valve, fuel heater, and water pump. The diesel preheating ends and the engine continues to work.

10. The method for controlling diesel preheating in extreme cold conditions according to claim 9, characterized in that: When the engine is operating normally, the return oil returns to the diesel tank through the return oil pipeline, which is equipped with a temperature sensor III, a flow control valve I, a flow control valve II and a fuel radiator; When the temperature sensor III detects that the diesel temperature t3 is lower than the return oil setting temperature T4, the vehicle controller controls the flow control valve II to open 100%, the flow control valve I to open 0%, and the diesel returns directly to the diesel tank through the flow control valve II; When the temperature sensor III detects that the diesel temperature t3 is higher than the return oil set temperature T5, the vehicle controller controls the flow control valve II to open 0% and the flow control valve I to open 100%. The diesel passes through the flow control valve I to the fuel radiator and then returns to the diesel tank after heat dissipation. When temperature sensor III detects that the diesel temperature is T4<t3≤T5, the vehicle controller controls the opening of flow control valve II to X, and the opening of flow control valve I is 1-X, X=(t3-T4) / (T5-T4)x100%; as the diesel temperature rises, the opening of flow control valve I increases, and the corresponding opening of flow control valve II decreases.

11. An engineering machine, characterized in that: It includes the extremely cold working condition diesel preheating control system as described in any one of claims 1 to 8.

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