Cold start control method and system for diesel engine and engine

Abstract

The invention relates to a cold start control method and system for a diesel engine and the engine. The cold start control method comprises the steps that an engine start instruction is obtained; detecting the temperature value of the cooling liquid; whether the temperature value of the cooling liquid is larger than a preset temperature threshold value or not is judged, and if yes, lubricating oil in an engine sump is extracted for pre-lubrication; and if not, cooling liquid preheating is conducted, and then lubricating oil in the engine sump is extracted for pre-lubrication. And finally, starting the engine. Whether the temperature of the cooling liquid is lower than the preset temperature threshold value or not is judged before pre-lubricating, so that the situation that the pre-lubricating oil pump cannot pump viscous lubricating oil is prevented. When the temperature is too low, the cooling liquid is preheated, then heat exchange is conducted on the cooling liquid pipe with the higher temperature in the engine and the lubricating oil pipe, and therefore the lubricating oil can be rapidly heated in a part needing to be lubricated and reaches a jet shape.

Description

Technical Field

[0001] The present application relates to the field of engine technology, and in particular to a cold start control method, system and engine for a diesel engine. Background Art

[0002] In extremely cold areas (20-40 degrees below zero), after a diesel engine has been shut down for a long time, the low temperature will increase the friction resistance between engine crankshaft and other parts, and increase the viscosity of the lubricating oil. When starting the diesel engine, the lubrication system needs to wait until the temperature of the cylinder rises to heat the lubricating oil. The lubricating oil can be sprayed out of the oil pipeline only after the viscosity of the lubricating oil becomes low.

[0003] Since the lubrication system has a period of dry grinding in a low-temperature environment, dry grinding will cause increased wear of engine components and increase the failure rate of diesel engines.

[0004] Especially for high-power diesel engines, it is necessary to ensure that the oil pressure reaches the threshold before starting to prevent mechanical problems such as dry grinding in the diesel engine.

[0005] Therefore, in order to prevent the occurrence of dry grinding problems, a pre-lubrication system is usually used for pre-lubrication before starting. The pre-lubrication system is generally provided with an electrically driven pre-lubrication oil pump, and lubricating oil is first extracted through the pre-lubrication oil pump before the engine is started.

[0006] However, the existing pre-lubrication system cannot complete pre-lubrication in extremely cold environments. Because the viscosity of the lubricating oil increases as the temperature decreases, especially in an environment below minus 20 degrees, the pre-lubrication oil pump needs to pressurize for a long time to reach the standard pressure. At the same time, the low temperature environment also has a negative impact on the power of the on-board power supply. In this case, the power of the on-board power supply is not enough to support the operation of the pre-lubrication oil pump, and the diesel engine needs to be powered to complete pre-lubrication.

[0007] Therefore, in a low temperature environment, in order to prevent pre-lubrication failure due to insufficient power, the present application provides a cold start control method, system and engine for a diesel engine. Summary of the invention

[0008] In order to overcome the problems existing in the related art, the first aspect of the present application provides a cold start control method for a diesel engine, comprising:

[0009] Get engine start command;

[0010] Detect the coolant temperature value;

[0011] Determine whether the coolant temperature value is greater than a preset temperature threshold value, if so, extract lubricating oil from the engine oil pan for pre-lubrication; if not, preheat the coolant and then extract lubricating oil from the engine oil pan for pre-lubrication;

[0012] Start the engine.

[0013] In one embodiment, the preheating of the coolant specifically includes:

[0014] Heating the engine coolant;

[0015] Obtaining the current heating time and the coolant temperature value;

[0016] Determine whether the coolant temperature is greater than the preset temperature threshold. If so, extract the lubricating oil in the engine oil pan for pre-lubrication; if not, determine whether the heating time at the current moment is greater than a first preset time. If so, extract the lubricating oil in the engine oil pan for pre-lubrication and send a first alarm message; if not, continue to heat the engine coolant.

[0017] In one embodiment, extracting lubricating oil from the engine oil pan for pre-lubrication specifically includes:

[0018] Pressurize the engine's lubricating oil circuit;

[0019] Get the current pressurization duration and lubricating oil pressure threshold;

[0020] Determine whether the lubricating oil pressure threshold at the current moment is greater than the preset pressure threshold. If so, start the engine; if not, determine whether the pressurization time is greater than the second preset time. If so, start the engine and send a second alarm message; if not, continue to pressurize the lubricating oil circuit of the engine.

[0021] A second aspect of the present application provides a cold start control system, the cold start control system is used to execute the cold start control method described in the first aspect of the present application;

[0022] The cold start control system comprises: a pre-lubrication module and a coolant preheating module electrically connected to the control module;

[0023] The pre-lubrication module includes a pre-lubrication oil pump and a pre-lubrication pipeline;

[0024] The coolant preheating module includes a coolant heater, a coolant preflow pump and a coolant preflow pipeline;

[0025] The control module is used to control the pre-lubrication module and the coolant preheating module according to the cold start control method.

[0026] In one embodiment, the coolant heater is provided with a fuel pipeline connected to the fuel tank, and the coolant heater draws fuel through the fuel pipeline;

[0027] The coolant pre-flow pipeline is fixed on the coolant heater; the coolant heater is used to burn the fuel drawn from the fuel tank to heat the coolant pre-flow pipeline, and the coolant pre-flow pipeline is connected to the cooling pipeline in the engine.

[0028] In one embodiment, the oil inlet and the oil outlet of the pre-lubricating oil pump are respectively connected to the pre-lubricating pipeline and the lubricating oil pipe in the engine;

[0029] The liquid inlet end and the liquid outlet end of the coolant pre-flow pump are respectively connected to the coolant pre-flow pipeline and the coolant pipe in the engine.

[0030] In one embodiment, the coolant pre-flow pump and the pre-lubricating oil pump are driven by a motor.

[0031] In one embodiment, the coolant pre-flow pump and the pre-lubricating oil pump are driven by a heat engine.

[0032] A third aspect of the present application provides an engine that performs pre-lubrication before starting based on the cold start control method described in the first aspect of the present application.

[0033] The technical solution provided by this application may have the following beneficial effects:

[0034] In the present application, in order to pre-lubricate the engine in an extremely cold environment, before the pre-lubrication oil pump works, it is also necessary to determine whether the lubricating oil needs to be heated based on the temperature of the coolant. After obtaining the engine start command, first detect whether the coolant temperature is too low, heat the low-temperature coolant, and drive the coolant circulation system to work, so that the heated coolant flows in the engine to preheat the parts to be lubricated. After the coolant temperature reaches the preset temperature threshold, the lubricating oil is drawn into the lubricating oil pipe of the engine. The present application preheats the coolant, and the coolant pipe with a higher temperature in the engine and the lubricating oil pipe perform heat exchange, so that the lubricating oil can quickly reach a spray state in the parts that need lubrication. The present application heats the coolant to heat the engine oil at low temperatures, and can concentrate the heating in the area of ​​the parts to be lubricated, which can reduce the energy required to heat the lubricating oil.

[0035] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and other objects, features and advantages of the present application will become more apparent through a more detailed description of exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0037] Figure 1A schematic diagram of a cold start control method according to an embodiment of the present application;

[0038] Figure 2 for Figure 1 A schematic flow chart of step S5 in the cold start control method shown;

[0039] Figure 3 for Figure 1 A schematic flow chart of step S4 in the cold start control method shown;

[0040] Figure 4 This is a schematic diagram of the logical structure of the cold start control system shown in an embodiment of the present application. DETAILED DESCRIPTION

[0041] The preferred embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0042] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0043] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0044] Embodiment 1

[0045] The existing pre-lubrication system cannot complete pre-lubrication in severe cold environments. Because the viscosity of the lubricating oil increases as the temperature decreases, especially in an environment below minus 20 degrees, the pre-lubrication oil pump needs to pressurize for a long time to reach the standard pressure. At the same time, the low temperature environment also has a negative impact on the power of the on-board power supply. In this case, the power of the on-board power supply is not enough to support the operation of the pre-lubrication oil pump, and the diesel engine needs to be powered to complete pre-lubrication.

[0046] In the actual cold start of a diesel engine, when facing an extremely cold environment and the pre-lubrication pressurization fails, the staff needs to add a heat source to the oil pan to heat the lubricating oil. The external heating method is unsafe, and it takes a long time to heat the lubricating oil in the entire oil pan from minus 20 degrees to minus 4 degrees.

[0047] In order to complete the cold start pre-lubrication of the engine in an extremely cold environment, the embodiment of the present application provides a cold start control method for a diesel engine, such as Figure 1 As shown, the following steps are included:

[0048] S1, obtaining an engine start command;

[0049] S2, detecting the coolant temperature value;

[0050] S3. Determine whether the coolant temperature value is greater than a preset temperature threshold. If so, execute step S4; if not, execute step S5 first, and then execute step S6.

[0051] Specifically, step S4 is to extract lubricating oil from the engine oil pan for pre-lubrication. Step S5 is to preheat the coolant. Step S6 is to start the engine.

[0052] Coolant pipelines are arranged around the cylinder, piston or turbine components inside the engine, and lubricating oil pipelines are also arranged inside the piston and turbine.

[0053] Therefore, the cold start control method described in the embodiment of the present application heats the coolant when facing an extremely cold environment, and then transfers the heat to the lubrication pipeline at the parts to be lubricated through the heated coolant, thereby preheating the lubricating oil in the engine and achieving rapid pre-lubrication.

[0054] In order to prevent the coolant preheating system and the pre-lubrication system from failing and causing the engine to be unable to start in an emergency, the embodiment of the present application also needs to determine whether to start the engine in an emergency based on the heating time and the pressurization time.

[0055] Further, such as Figure 2 Said step S5 specifically comprises:

[0056] S501, heating the coolant of the engine;

[0057] S502, obtaining the current heating time and the coolant temperature value;

[0058] S503, determine whether the coolant temperature is greater than the preset temperature threshold, if so, execute step S4; if not, execute step S504: determine whether the heating time at the current moment is greater than the first preset time, if so, send a first alarm message; if not, continue to execute step S501.

[0059] Specifically, the coolant pre-flow pump of the engine described in the embodiment of the present application is provided with a coolant heater and a coolant pre-flow pump.

[0060] Preferably, the coolant pre-flow pump takes power from a device different from the engine belt system, and the coolant heater can be heated by drawing electricity from an on-board battery, or by a separately arranged gas system.

[0061] Further, such as Figure 3 As shown, the step S4 specifically includes:

[0062] S401, pressurizing the lubricating oil circuit of the engine;

[0063] S402, obtaining the current pressurization duration and lubricating oil pressure value;

[0064] S403, judging whether the lubricating oil pressure value at the current moment is greater than the preset pressure threshold value, if so, executing step S6; if not, executing step S404, i.e. judging whether the pressurization time is greater than the second preset time, if so, executing step S6, and sending the second alarm information;

[0065] If not, continue to execute step S401.

[0066] Specifically, the lubricating oil circuit of the engine described in the embodiment of the present application is provided with a pre-lubricating oil pump. Before the engine is started, the pre-lubricating oil pump takes power from a separately provided power system and then pressurizes the lubricating oil circuit of the engine.

[0067] In the embodiment of the present application, in order to pre-lubricate the engine in an extremely cold environment, before the pre-lubrication oil pump works, it is also necessary to determine whether the lubricating oil needs to be heated based on the temperature of the coolant.

[0068] After receiving the engine start command, the coolant temperature is first detected to see if it is too low, the low-temperature coolant is heated, and the coolant circulation system is driven to work, so that the heated coolant flows in the engine to preheat the parts to be lubricated. After the coolant temperature reaches the preset temperature threshold, the lubricating oil is drawn into the lubricating oil pipe of the engine. The embodiment of the present application preheats the coolant, and the coolant pipe with a higher temperature in the engine and the lubricating oil pipe perform heat exchange, so that the lubricating oil can quickly heat up in the parts that need to be lubricated and reach a spray state.

[0069] The embodiment of the present application heats the engine oil at low temperatures by heating the coolant, which can concentrate the heating on the area of ​​the parts to be lubricated and reduce the energy required to heat the lubricating oil.

[0070] Embodiment 2

[0071] Based on the cold start control method for cold start of a diesel engine described in the first embodiment, the present application provides a cold start control system based on the control method. Figure 4 As shown, the cold start control system includes a pre-lubrication module and a coolant preheating module electrically connected to the control module.

[0072] Wherein, the pre-lubrication module includes a pre-lubrication oil pump and a pre-lubrication pipeline. The pre-lubrication pipeline is connected to the lubricating oil pipe in the engine. The coolant preheating module includes a coolant heater, a coolant pre-flow pump and a coolant pre-flow pipeline. The coolant pre-flow pipeline is connected to the coolant pipe in the engine. The control module is used to control the pre-lubrication module and the coolant preheating module according to the cold start control method.

[0073] It is understandable that the viscosity of the engine's lubricating oil is high, and ordinary centrifugal pumps cannot achieve pressurization. Ordinary diesel engines use gear pumps for pressurization. During pre-lubrication, the temperature of the lubricating oil is low, the viscosity is high, and the flow rate increases as the viscosity increases. If the lubricating oil in the pipeline is directly heated, part of the lubricating oil will evaporate. Lubricating oil is an organic substance with a low boiling point and a heat transfer coefficient of only about 0.2 of water.

[0074] Therefore, the pre-lubrication system of the embodiment of the present application is provided with a coolant preheating module, which utilizes the highly overlapping distribution of coolant pipes and lubricating oil pipes in the engine to quickly preheat the lubricating oil pipes of the parts to be lubricated through the coolant preheating module, so that the parts to be lubricated can be quickly pre-lubricated.

[0075] Since the onboard power capacity of engineering vehicles such as excavators is limited, the coolant heater in the embodiment of the present application is boiler heating.

[0076] Specifically, the coolant heater is provided with a fuel pipeline connected to the fuel tank, and the coolant heater extracts fuel through the fuel pipeline. The coolant heater is arranged around the outer side of the coolant pre-flow pipeline, and the coolant heater is used to burn the fuel extracted from the fuel tank to heat the coolant pre-flow pipeline.

[0077] Optionally, the coolant heater may be a resistance heating wire arranged around the coolant pre-flow pipe or an electromagnetic induction coil for heating.

[0078] In the embodiment of the present application, when the coolant is heated, oil is directly drawn from the oil tank and ignited for heating. The coolant pre-flow pipeline is arranged near the heat source.

[0079] Specifically, the oil inlet and outlet of the pre-lubricating oil pump are connected to the pre-lubricating pipeline and the lubricating oil pipe in the engine respectively. The liquid inlet and outlet of the coolant pre-flow pump are connected to the coolant pre-flow pipeline and the coolant pipe in the engine respectively.

[0080] In an embodiment of the present application, the pre-lubrication oil pump and the coolant pre-flow pump are connected to the pre-lubrication starter via a belt system.

[0081] Optionally, the pre-lubrication starter may be an electric motor electrically connected to a vehicle battery.

[0082] In an extremely cold environment, in order to avoid the inability to pre-lubricate due to the attenuation of the capacity of the vehicle battery, the pre-lubrication starter in the embodiment of the present application is a thermal engine.

[0083] Specifically, the pre-lubricating starter is a gas turbine. The gas turbine is provided with an air inlet, a compressor, a combustion chamber, a turbine and an exhaust port in sequence along its axial direction. The combustion chamber of the gas turbine is connected to an oil tank for pumping oil. The turbine is respectively connected to the pre-lubricating oil pump and the coolant pre-flow pump.

[0084] Furthermore, a heating plate is arranged around the axial direction of the pre-lubricating starter, and the coolant pre-flow pipeline is fixed on the outer side of the heating plate. The inner side of the heating plate surrounds the combustion chamber of the gas turbine.

[0085] In the embodiment of the present application, a small diesel gas wheel ring is added as a driving device for the pre-lubricating oil pump and the coolant pre-flow pump, and the fuel is directly drawn from the diesel tank as energy. A heating plate is arranged outside the combustion chamber of the gas turbine to radiantly heat the coolant preheating pipeline.

[0086] Embodiment 3

[0087] An engine is equipped with a cold start control system or device implemented based on the cold start control method described in the first embodiment.

[0088] Regarding the device in the above embodiment, the specific way in which each module performs the operation has been described in detail in the embodiment of the method, and will not be elaborated here.

[0089] The scheme of the present application has been described in detail above with reference to the accompanying drawings. In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments. Those skilled in the art should also be aware that the actions and modules involved in the description are not necessarily required for the present application.

[0090] In addition, it can be understood that the steps in the method of the embodiment of the present application can be adjusted in order, combined and deleted according to actual needs, and the modules in the device of the embodiment of the present application can be combined, divided and deleted according to actual needs.

[0091] In addition, the method according to the present application may also be implemented as a computer program or a computer program product, which includes computer program code instructions for executing some or all of the steps in the above method of the present application.

[0092] Alternatively, the present application can also be implemented as a non-temporary machine-readable storage medium (or computer-readable storage medium, or machine-readable storage medium) on which executable code (or computer program, or computer instruction code) is stored. When the executable code (or computer program, or computer instruction code) is executed by a processor of an electronic device (or electronic device, server, etc.), the processor executes part or all of the steps of the above-mentioned method according to the present application.

[0093] Those skilled in the art will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the application herein may be implemented as electronic hardware, computer software, or combinations of both.

[0094] The flow chart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system and method according to multiple embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a part of a module, a program segment or a code, and the part of the module, the program segment or the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two continuous square boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or the flow chart, and the combination of the square boxes in the block diagram and / or the flow chart can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0095] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A cold start control method for a diesel engine, characterized in that: include: Get engine start command; Detect the coolant temperature value; determining whether the coolant temperature value is greater than a preset temperature threshold, and if so, extracting lubricating oil from the engine oil pan for pre-lubrication; If not, preheat the coolant and draw lubricating oil from the engine oil pan for pre-lubrication; Start the engine.

2. A cold start control method for a diesel engine according to claim 1, characterized in that: The coolant preheating specifically includes: Heating the engine coolant; Obtaining the current heating time and the coolant temperature value; Determine whether the coolant temperature is greater than the preset temperature threshold. If so, extract the lubricating oil in the engine oil pan for pre-lubrication; if not, determine whether the heating time at the current moment is greater than a first preset time. If so, extract the lubricating oil in the engine oil pan for pre-lubrication and send a first alarm message; if not, continue to heat the engine coolant.

3. A cold start control method for a diesel engine according to claim 2, characterized in that: The step of extracting lubricating oil from the engine oil pan for pre-lubrication specifically includes: Pressurize the engine's lubricating oil circuit; Get the current pressurization duration and lubricating oil pressure threshold; Determine whether the lubricating oil pressure threshold at the current moment is greater than the preset pressure threshold. If so, start the engine; if not, determine whether the pressurization time is greater than the second preset time. If so, start the engine and send a second alarm message; if not, continue to pressurize the lubricating oil circuit of the engine.

4. A cold start control system, characterized in that: Used to execute the cold start control method according to any one of claims 1 to 3; The cold start control system comprises: a pre-lubrication module and a coolant preheating module electrically connected to the control module; The pre-lubrication module includes a pre-lubrication oil pump and a pre-lubrication pipeline; The coolant preheating module includes a coolant preheater, a coolant preflow pump and a coolant preflow pipeline; The control module is used to control the pre-lubrication module and the coolant preheating module to start the engine according to the cold start control method.

5. A cold start control system according to claim 4, characterized in that: The coolant heater is provided with a fuel pipeline connected to the fuel tank, and the coolant heater draws fuel through the fuel pipeline; The coolant pre-flow pipeline is fixed on the coolant heater; the coolant heater is used to burn the fuel drawn from the fuel tank to heat the coolant pre-flow pipeline, and the coolant pre-flow pipeline is connected to the cooling pipeline in the engine.

6. A cold start control system according to claim 4, characterized in that: The oil inlet end and the oil outlet end of the pre-lubricating oil pump are respectively connected to the pre-lubricating pipeline and the lubricating oil pipe in the engine; The liquid inlet end and the liquid outlet end of the coolant pre-flow pump are respectively connected to the coolant pre-flow pipeline and the coolant pipe in the engine.

7. A cold start control system according to claim 6, characterized in that: The coolant pre-flow pump and the pre-lubricating oil pump are driven by a motor.

8. A cold start control system according to claim 6, characterized in that: The coolant pre-flow pump and the pre-lubricating oil pump are driven by a heat engine.

9. An engine, characterized in that: Pre-lubrication before starting is performed based on the cold start control method according to any one of claims 1 to 3.

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