Temperature control method and system for multi-fuel engine

Abstract

The invention discloses a temperature control method and system for a multi-fuel engine, and the engine comprises a fuel oil part temperature control device which mainly comprises the steps: firstly obtaining the fuel oil type, then matching the fuel oil type with a preset type, and if the fuel oil type is matched with the preset type, judging whether the engine is in a running state or a shutdown state; if so, generating a shutdown temperature control signal; according to the shutdown temperature control signal, a fuel oil part temperature adjusting device is closed; or judging whether the fuel component needs heat preservation or not; if heat preservation is not needed, the fuel oil part temperature adjusting device is closed; if heat preservation is needed, a heat preservation signal is generated, and a fuel oil part temperature adjusting device is controlled to start a heating function and stop a cooling function according to the heat preservation signal. Therefore, when the multi-fuel engine uses different fuels and the engine is shut down, different modes are adopted to control the temperature of the fuel oil component, normal operation of the engine is guaranteed, heat preservation can be conducted on the fuel oil component in the fuel oil pipeline in the heavy oil and biodiesel modes, and the engine can be normally shut down and restarted.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and particularly to a temperature control method and control system for a multi-fuel engine. Background Art

[0002] With the development of the marine engine industry, there are increasing requirements for the types of fuels that engines can burn, such as light diesel oil, heavy oil, biodiesel, etc. Engines often have requirements for burning more than two types of fuels. When the engine is in operation and stopped states, the temperature requirements for fuel components are different when burning different fuels. Currently, for engines that can burn more than two types of fuels, a general temperature control method is adopted for the temperature control of fuel components during operation, which may cause engine failures or waste of energy in cooling equipment, and it is impossible to achieve accurate temperature control of fuel components for a specific fuel. When the engine stops, unique temperature control of fuel components should also be carried out for different fuel states during parking, and it is impossible to ensure the normal operation of the engine.

[0003] A multi-fuel engine is an engine that can burn two, three or more types of fuels; such as light diesel oil, heavy oil and biodiesel. Light diesel oil is diesel oil with a relatively light density; heavy oil is the remaining heavy oil after gasoline and diesel are extracted from crude oil; biodiesel is a renewable energy produced from biomass such as waste grease. Summary of the Invention

[0004] In view of the above deficiencies, the technical problem to be solved by the present invention is: to provide a temperature control method for a multi-fuel engine, which can adopt different temperature control methods according to the current fuel type and the engine operating state to ensure the normal operation of the engine. In particular, when parking in heavy oil and biodiesel modes, temperature control of fuel components in the fuel pipeline can be carried out, so that the engine can be stopped and restarted normally.

[0005] To solve the above technical problem, the technical solution of the present invention is as follows:

[0006] A temperature control method for a multi-fuel engine, the multi-fuel engine includes a fuel component temperature regulation device, and the temperature control method includes the following steps:

[0007] Obtain the current fuel type of the engine;

[0008] Judge whether the fuel type matches the preset type;

[0009] If it matches, then judge whether the engine is in an operating state or a stopped state;

[0010] If the engine is in a stopped state, generate a corresponding stopped temperature control signal;

[0011] According to the shutdown temperature control signal, shut down the fuel component temperature control device; or; According to the shutdown temperature control signal, determine whether the fuel components need heat preservation;

[0012] If the fuel components do not need heat preservation, shut down the fuel component temperature control device; if the fuel components need heat preservation, generate a corresponding heat preservation signal, and according to the heat preservation signal, control the fuel component temperature control device to turn off the cooling function and turn on the heating function.

[0013] Preferably, the step of determining whether the fuel type matches the preset type includes: determining whether the fuel type matches the preset light diesel type;

[0014] The step of if it matches, then determining whether the engine is in the running state or the shutdown state includes: if the fuel type matches the light diesel type, generate a corresponding light diesel temperature control signal, and then determine whether the engine is in the running state or the shutdown state;

[0015] The step of if the engine is in the shutdown state, generating a corresponding shutdown temperature control signal includes: if the engine is in the shutdown state, then generate a corresponding light diesel shutdown temperature control signal according to the light diesel temperature control signal;

[0016] The step of shutting down the fuel component temperature control device according to the shutdown temperature control signal is: shutting down the fuel component temperature control device according to the light diesel shutdown temperature control signal.

[0017] Preferably, the step of determining whether the fuel type matches the preset type includes: determining whether the fuel type matches the preset biodiesel type;

[0018] The step of if it matches, then determining whether the engine is in the running state or the shutdown state includes: if the fuel type matches the preset biodiesel type, generate a corresponding biodiesel temperature control signal, and then determine whether the engine is in the running state or the shutdown state;

[0019] The step of if the engine is in the shutdown state, generating a corresponding shutdown temperature control signal includes: if the engine is in the shutdown state, then generate a corresponding biodiesel shutdown temperature control signal according to the biodiesel temperature control signal;

[0020] The step of shutting down the fuel component temperature control device according to the shutdown temperature control signal is: determining whether the fuel components need heat preservation according to the biodiesel shutdown temperature control signal;

[0021] The step of if the fuel components need heat preservation, generating a corresponding heat preservation signal is: if the fuel components need heat preservation, generate a corresponding biodiesel heat preservation signal;

[0022] The steps of controlling the temperature regulating device of the fuel component to close the cooling function and turn on the heating function according to the heat preservation signal are as follows: According to the biodiesel heat preservation signal, control the temperature regulating device of the fuel component to close the cooling function and turn on a part of the heating function.

[0023] Preferably, the step of judging whether the fuel type matches the preset type includes: judging whether the fuel type matches the preset heavy oil type;

[0024] The steps of if it matches, then judging whether the engine is in the running state or the stopped state include: If the fuel type matches the preset heavy oil type, generate a corresponding heavy oil temperature control signal, and then judge whether the engine is in the running state or the stopped state;

[0025] The steps of if the engine is in the stopped state, generating a corresponding stopped state temperature control signal include: If the engine is in the stopped state, then generate a corresponding heavy oil stopped state temperature control signal according to the heavy oil temperature control signal;

[0026] The steps of closing the temperature regulating device of the fuel component according to the stopped state temperature control signal are as follows: According to the heavy oil stopped state temperature control signal, judge whether the fuel component needs heat preservation;

[0027] The steps of if the fuel component needs heat preservation, generating a corresponding heat preservation signal include: If the fuel component needs heat preservation, generate a corresponding heavy oil heat preservation signal;

[0028] The steps of controlling the temperature regulating device of the fuel component to close the cooling function and turn on the heating function according to the heat preservation signal are as follows: According to the heavy oil heat preservation signal, control the temperature regulating device of the fuel component to close the cooling function and turn on all the heating functions.

[0029] Preferably, the steps of if the engine is in the stopped state, generating a corresponding stopped state temperature control signal further include: If the engine is in the running state, generate a corresponding running state temperature control signal;

[0030] The steps of closing the temperature regulating device of the fuel component according to the stopped state temperature control signal further include: According to the running state temperature control signal, judge whether the fuel temperature is too high;

[0031] If the fuel temperature is too high, generate a corresponding cooling signal;

[0032] If the fuel temperature is not too high, close the temperature regulating device of the fuel component;

[0033] According to the cooling signal, control the temperature regulating device of the fuel component to turn off the heating function, turn on the cooling function, and then judge whether the fuel temperature is too high.

[0034] Preferably, when the fuel type matches the preset heavy oil type, according to the cooling signal, the temperature control device of the fuel component is controlled to turn off the heating function and turn on all cooling functions, and then it is judged whether the fuel temperature is too high; when the fuel type matches the preset light diesel oil type or the preset biodiesel, according to the cooling signal, the temperature control device of the fuel component is controlled to turn off the heating function and turn on partial cooling functions, and then it is judged whether the fuel temperature is too high.

[0035] A temperature control system for a multi-fuel engine, comprising an electronic control unit and a fuel type detection unit, an operating state detection unit, a temperature detection unit, a temperature control unit, an injector temperature control device and a fuel injection pump temperature control device which are electrically connected to the electronic control unit respectively; the fuel type detection unit is used for detecting the current fuel type of the engine and transmitting the corresponding fuel type signal to the electronic control unit; the operating detection unit is used for detecting whether the engine is in an operating state and transmitting the corresponding state signal to the electronic control unit; the temperature detection unit is used for detecting the fuel temperature and transmitting the corresponding fuel temperature signal to the electronic control unit; the injector temperature control device comprises two groups of fresh water heaters, two groups of fresh water coolers and a fresh water electric pump; the fuel injection pump temperature control device comprises an oil heater, an oil cooler and an oil electric pump; the electronic control unit transmits the fuel type signal, the state signal and the fuel temperature signal to the temperature control unit, and the temperature control unit transmits the corresponding temperature control signal to the electronic control unit according to the received fuel type signal, state signal and fuel temperature signal to control the injector temperature control device and the fuel injection pump temperature control device.

[0036] Preferably, the temperature control unit comprises a light diesel oil temperature control unit. When the fuel type signal received by the temperature control unit is light diesel oil, the light diesel oil temperature control unit is started; the light diesel oil temperature control unit is used for transmitting the corresponding shutdown signal to the electronic control unit to turn off the injector temperature control device and the fuel injection pump temperature control device when the state signal is shutdown; the light diesel oil temperature control unit is used for judging whether the fuel temperature signal is greater than a preset temperature threshold when the state signal is operating. If the fuel temperature signal is greater than the preset temperature threshold, a corresponding opening signal is generated to the electronic control unit to turn off the fresh water heater and the oil heater and turn on one group of the fresh water coolers, the fresh water electric pump, the oil cooler and the oil electric pump.

[0037] Preferably, the temperature control unit includes a biodiesel temperature control unit. When the fuel type signal received by the temperature control unit is biodiesel, the biodiesel temperature control unit is started. The biodiesel temperature control unit is used to judge whether the fuel components need heat preservation when the status signal is shutdown. If the fuel components do not need heat preservation, a corresponding shutdown signal is transmitted to the electronic control unit to shut down the fuel injector temperature control device and the fuel injection pump temperature control device. If the fuel components need heat preservation, a corresponding heat preservation signal is transmitted to the electronic control unit to turn on a group of the fresh water heaters, the engine oil heaters, the fresh water electric pumps and the engine oil electric pumps. The biodiesel temperature control unit is used to judge whether the fuel temperature signal is greater than a preset temperature threshold when the status signal is running. If the fuel temperature signal is not greater than the preset temperature threshold, a corresponding shutdown signal is transmitted to the electronic control unit to shut down the fuel injector temperature control device and the fuel injection pump temperature control device. If the fuel temperature signal is greater than the preset temperature threshold, a corresponding turn-on signal is generated and transmitted to the electronic control unit to turn off the engine oil heaters and the fresh water heaters and turn on the fresh water cooler, the engine oil cooler, the engine oil electric pumps and the fresh water electric pumps.

[0038] Preferably, the temperature control unit includes a heavy oil temperature control unit. When the fuel type signal received by the temperature control unit is heavy oil, the heavy oil temperature control unit is started. The heavy oil temperature control unit is used to judge whether the fuel components need heat preservation when the status signal is shutdown. If the fuel components do not need heat preservation, a corresponding shutdown signal is transmitted to the electronic control unit to shut down the fuel injector temperature control device and the fuel injection pump temperature control device. If the fuel components need heat preservation, a corresponding heat preservation signal is transmitted to the electronic control unit to turn on two groups of the fresh water heaters, the engine oil heaters, the fresh water electric pumps and the engine oil electric pumps. The heavy oil temperature control unit is used to judge whether the fuel temperature signal is greater than a preset temperature threshold when the status signal is running. If the fuel temperature signal is not greater than the preset temperature threshold, a corresponding shutdown signal is transmitted to the electronic control unit to shut down the fuel injector temperature control device and the fuel injection pump temperature control device. If the temperature signal is greater than the preset temperature threshold, a corresponding turn-on signal is generated and transmitted to the electronic control unit to turn off the engine oil heaters and the fresh water heaters and turn on two groups of the fresh water coolers, the engine oil coolers, the fresh water electric pumps and the engine oil electric pumps.

[0039] After adopting the above technical solution, the beneficial effects of the present invention are:

[0040] For the temperature control method and control system of the multi-fuel engine of the present invention, it obtains the current fuel type of the engine; then determines whether the fuel type matches the preset type; if it matches, it further determines whether the engine is in a running state or a stopped state; if the engine is in a stopped state, it generates a corresponding stopped state temperature control signal; according to the stopped state temperature control signal, it closes the fuel component temperature control device; or; according to the stopped state temperature control signal, it determines whether the fuel components need heat preservation; if the fuel components need heat preservation, it generates a corresponding heat preservation signal; if the fuel components do not need heat preservation, it closes the fuel component temperature control device; according to the heat preservation signal, it controls the fuel component temperature control device to turn on the heating function and turn off the cooling function. It can be seen that the present invention adopts different methods for temperature control of fuel components when the multi-fuel engine uses different fuels and is in a stopped state, to ensure the normal operation of the engine. For example, when stopping in the heavy oil and biodiesel modes, it can perform temperature control on the fuel components in the fuel pipeline to enable the engine to stop and start again normally. Description of the Drawings

[0041] Figure 1 is a schematic flowchart of the temperature control method of the multi-fuel engine in the present invention;

[0042] Figure 2 is a schematic block diagram of the temperature control system of the multi-fuel engine in the present invention;

[0043] In the figure: 1 - temperature control unit, 2 - fuel injection pump temperature control device, 20 - engine oil electric pump, 3 - injector temperature control device, 30 - fresh water electric pump. Detailed Embodiments

[0044] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0045] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "up", "down", "left", "right", "inside", "outside", etc. are based on the directions or positional relationships shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0046] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and defined, the terms "installation", "connection", and "linkage" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0047] Embodiment 1:

[0048] As Figure 1 shown, a temperature control method for a multi-fuel engine can be applied to the temperature control system of the multi-fuel engine described in the embodiment. The multi-fuel engine includes a fuel component temperature control device. The temperature control method includes the following steps:

[0049] S10. Obtain the current fuel type of the engine;

[0050] It should be noted that: the engine fuel in the present invention may include but is not limited to light diesel, biodiesel, and heavy oil. The fuel type can be obtained through the current operating mode of the engine.

[0051] S20. Determine whether the fuel type matches the preset type;

[0052] S30. If it matches, then determine whether the engine is in an operating state or a shutdown state;

[0053] It should be noted that: this step is equivalent to determining whether the engine is in an operating state. To determine whether the engine is in an operating state or a shutdown state, it can be determined through parameters such as the engine speed. In the present invention, different temperature controls are mainly performed on the fuel components according to the two states of the engine shutdown and operation.

[0054] S40. If the engine is in a shutdown state, generate a corresponding shutdown temperature control signal;

[0055] S50. According to the shutdown temperature control signal, turn off the fuel component temperature control device; or; according to the shutdown temperature control signal, determine whether the fuel component needs heat preservation;

[0056] It should be noted that: when the engine is in a shutdown state, due to the characteristics of high viscosity and low freezing point of heavy oil and biodiesel, when stopping in the heavy oil and biodiesel combustion modes, as the engine temperature decreases, the remaining heavy oil and biodiesel will solidify in the fuel components, causing the entire pipeline to be blocked, affecting the next engine start, and even causing damage to the fuel system. Therefore, it is necessary to determine whether the fuel component needs heat preservation.

[0057] S60. If the fuel components need heat preservation, generate corresponding heat preservation signals;

[0058] If the fuel components do not need heat preservation, turn off the temperature control device of the fuel components;

[0059] It should be noted that whether the fuel components need heat preservation can be input through the man-machine interaction unit. For example, when the engine is running in the biodiesel mode or heavy oil mode and needs to be restarted after a period of shutdown, the fuel components need heat preservation. If the engine is not restarted within one or two days after shutdown, the fuel components do not need heat preservation. Of course, it can also be preset. For example, before shutdown, as long as the engine is running in the biodiesel mode or heavy oil mode, it can be preset that the fuel components need heat preservation, otherwise, the fuel components do not need heat preservation.

[0060] S70. According to the heat preservation signal, control the temperature control device of the fuel components to turn off the cooling function and turn on the heating function.

[0061] The temperature control method of the multi-fuel engine of the present invention adopts different methods for temperature control of fuel components when the multi-fuel engine uses different fuels and the engine is in a shutdown state, so as to ensure the normal operation of the engine. For example, when heavy oil and biodiesel need to be stopped, the temperature of the fuel components in the fuel pipeline can be controlled to enable the engine to stop and start again normally; and the present invention has the advantages of simple operation, low cost and easy wide use.

[0062] As Figure 2 shown, in this embodiment, the temperature control device of the fuel components includes an injector temperature control device 3 and a fuel injection pump temperature control device 2. The injector temperature control device 3 includes two groups of fresh water heaters, two groups of fresh water coolers and a fresh water electric pump 30. The fuel injection pump temperature control device 2 includes an engine oil heater, an engine oil cooler and an engine oil electric pump 20.

[0063] As Figure 1 shown, when the engine is running in the light diesel mode, the temperature control method of this embodiment specifically includes the following steps:

[0064] S10. Obtain the current fuel type of the engine;

[0065] S200. Judge whether the fuel type matches the preset light diesel type;

[0066] S300. If the fuel type matches the light diesel type, generate a corresponding light diesel temperature control signal, and then judge whether the engine is in the running state or the shutdown state;

[0067] S400. If the engine is in the shutdown state, generate a corresponding light diesel shutdown temperature control signal according to the light diesel temperature control signal;

[0068] S500. Close the temperature control device of the fuel components according to the light diesel shutdown temperature control signal.

[0069] From the above steps, it can be seen that when the present invention detects that the current fuel type of the engine is light diesel and the engine is in the shutdown state, there is no need to perform temperature control on the fuel components, and the temperature control device of the fuel components can be closed.

[0070] As Figure 1 shown, when the engine is operating in the biodiesel mode, the temperature control method of this embodiment specifically includes the following steps:

[0071] S10. Obtain the current fuel type of the engine;

[0072] S201. Judge whether the fuel type matches the preset biodiesel type;

[0073] S301. If the fuel type matches the preset biodiesel type, generate a corresponding biodiesel temperature control signal, and then judge whether the engine is in the running state or the shutdown state;

[0074] S401. If the engine is in the shutdown state, generate a corresponding biodiesel shutdown temperature control signal according to the biodiesel temperature control signal;

[0075] S501. Judge whether the fuel components need heat preservation according to the biodiesel shutdown temperature control signal;

[0076] S601. If the fuel components need heat preservation, generate a corresponding biodiesel heat preservation signal;

[0077] If the fuel components do not need heat preservation, close the temperature control device of the fuel components;

[0078] S701. According to the biodiesel heat preservation signal, control the temperature control device of the fuel components to close the cooling function and turn on 1 group of fresh water heaters, fresh water electric pumps, oil heaters and oil electric pumps.

[0079] From the above steps, it can be seen that when the present invention detects that the current fuel type of the engine is biodiesel and the engine is in the shutdown state, the fuel components need to be heat-preserved, and according to the characteristics of biodiesel, the temperature control device of the fuel components is controlled to turn on part of the heating function to prevent the remaining biodiesel from solidifying in the fuel components as the engine temperature decreases, causing the entire pipeline to be blocked, affecting the next engine start, and even causing damage to the fuel system. It can be seen that after adopting the temperature control method of the present invention, the normal shutdown and restart of the engine can be ensured, and the engine can operate normally.

[0080] As Figure 1 shown, when the engine is operating in the heavy oil mode, the temperature control method of this embodiment specifically includes the following steps:

[0081] S10. Obtain the current fuel type of the engine;

[0082] S202. Determine whether the fuel type matches the preset heavy oil type;

[0083] S302. If the fuel type matches the preset heavy oil type, generate a corresponding heavy oil temperature control signal, and then determine whether the engine is in an operating state or a shutdown state;

[0084] S402. If the engine is in a shutdown state, generate a corresponding heavy oil shutdown temperature control signal according to the heavy oil temperature control signal;

[0085] S502. Determine whether the fuel components need to be heat-insulated according to the heavy oil shutdown temperature control signal;

[0086] S602. If the fuel components need to be heat-insulated, generate a corresponding heavy oil heat-insulation signal;

[0087] If the fuel components do not need to be heat-insulated, turn off the temperature control device of the fuel components;

[0088] S702. According to the heavy oil heat-insulation signal, control the temperature control device of the fuel components to turn off the cooling function and turn on two groups of fresh water heaters, fresh water electric pumps, oil heaters and oil electric pumps.

[0089] From the above steps, it can be seen that when the present invention detects that the current fuel type of the engine is heavy oil and the engine is in a shutdown state, the fuel components need to be heat-insulated; and according to the characteristics of heavy oil, control the temperature control device of the fuel components to turn on all heating functions, so as to prevent the remaining heavy oil from solidifying in the fuel components as the engine temperature decreases, causing the entire pipeline to be blocked, affecting the next engine start, and even causing damage to the fuel system. It can be seen that after adopting the temperature control method of the present invention, the normal shutdown and restart of the engine can be ensured, and the engine can operate normally.

[0090] As Figure 1 shown, the temperature control method of the multi-fuel engine in this embodiment further includes the control method when the engine is in an operating state and the fuel type is light diesel, which is as follows:

[0091] S10. Obtain the current fuel type of the engine;

[0092] S200. Determine whether the fuel type matches the preset light diesel type;

[0093] S300. If the fuel type matches the light diesel type, generate a corresponding light diesel temperature control signal, and then determine whether the engine is in an operating state or a shutdown state;

[0094] S403. If the engine is in the running state, generate a corresponding light diesel oil running temperature control signal based on the light diesel oil temperature control signal.

[0095] S503. Execute S80 according to the light diesel oil running temperature control signal.

[0096] S80. Judge whether the fuel temperature is too high.

[0097] It should be noted that the fuel temperature can be detected by a temperature sensor. To judge whether the fuel temperature is too high, it can specifically judge whether the fuel temperature is greater than a preset temperature threshold, or it can also judge whether the fuel temperature is within a preset temperature range.

[0098] S900. If the fuel temperature is too high, it indicates that the fuel needs to be cooled at this time, and generate a corresponding light diesel oil cooling signal.

[0099] If the fuel temperature is not too high, it indicates that temperature control is not required at this time, and turn off the fuel component temperature control device.

[0100] S1000. According to the light diesel oil cooling signal, control the fuel component temperature control device to turn off the heating function and turn on part of the cooling function. Specifically, turn on a set of fresh water coolers, fresh water electric pumps, oil coolers and oil electric pumps, and then execute S80, that is, when the engine is in the running state, repeatedly judge the fuel temperature to control the fuel component temperature control device in real time.

[0101] From the above steps, it can be seen that when the present invention detects that the current fuel type of the engine is light diesel oil and the engine is in the running state, it performs fuel temperature control to ensure the normal operation of the engine.

[0102] As Figure 1 shown, the temperature control method of the multi-fuel engine in this embodiment further includes the control method when the engine is in the running state and the fuel type is biodiesel, which is specifically as follows:

[0103] S10. Obtain the current fuel type of the engine.

[0104] S201. Judge whether the fuel type matches the preset biodiesel type.

[0105] S301. If the fuel type matches the biodiesel type, generate a corresponding biodiesel temperature control signal, and then judge whether the engine is in the running state or the shutdown state.

[0106] S404. If the engine is in the running state, generate a corresponding biodiesel running temperature control signal based on the biodiesel temperature control signal.

[0107] S504. Execute S80 according to the biodiesel light running temperature control signal.

[0108] S80. Determine whether the fuel temperature is too high;

[0109] S901. If the fuel temperature is too high, it indicates that the fuel needs to be cooled at this time, and a corresponding biodiesel cooling signal is generated;

[0110] If the fuel temperature is not too high, it indicates that temperature control is not required at this time, and the fuel component temperature regulating device is turned off;

[0111] S1001. According to the biodiesel cooling signal, control the fuel component temperature regulating device to turn off the heating function and turn on part of the cooling function. Specifically, turn on a set of fresh water coolers, fresh water electric pumps, oil coolers and oil electric pumps, and then execute S80, that is, when the engine is in operation, repeatedly judge the fuel temperature to control the fuel component temperature regulating device in real time.

[0112] From the above steps, it can be seen that when the present invention detects that the current fuel type of the engine is biodiesel and the engine is in operation, it performs fuel temperature control, controls the cooling function and heating function of the fuel component temperature regulating device to ensure the normal operation of the engine.

[0113] As Figure 1 shown, the temperature control method of the multi-fuel engine in this embodiment further includes the control method when the engine is in operation and the fuel type is heavy oil, which is specifically as follows:

[0114] S10. Obtain the current fuel type of the engine;

[0115] S202. Determine whether the fuel type matches the preset heavy oil type;

[0116] S302. If the fuel type matches the biodiesel type, generate a corresponding heavy oil temperature control signal, and then judge whether the engine is in operation or in a shutdown state;

[0117] S405. If the engine is in operation, generate a corresponding heavy oil operation temperature control signal according to the heavy oil temperature control signal;

[0118] S505. According to the biodiesel light oil operation temperature control signal, execute S80;

[0119] S80. Determine whether the fuel temperature is too high;

[0120] S902. If the fuel temperature is too high, it indicates that the fuel needs to be cooled at this time, and a corresponding heavy oil cooling signal is generated;

[0121] If the fuel temperature is not too high, it indicates that temperature control is not required at this time, and the fuel component temperature regulating device is turned off;

[0122] S1002. According to the heavy oil cooling signal, control the fuel component temperature regulating device to turn off the heating function and turn on part of the cooling function. Specifically, turn on two groups of fresh water coolers, fresh water electric pumps, oil coolers and oil electric pumps, and then execute S80, that is, when the engine is in the running state, repeatedly judge the fuel temperature to control the fuel component temperature regulating device in real time.

[0123] As can be seen from the above steps, when the present invention detects that the current fuel type of the engine is heavy oil and the engine is in the running state, it performs fuel temperature control, controls the cooling function and heating function of the fuel component temperature regulating device to ensure the normal operation of the engine.

[0124] In summary, the present invention uses a specific temperature control scheme for different fuels burned during the operation of a multi-fuel engine to ensure the normal operation of the engine; when the engine is in the shutdown state, due to the high viscosity and low freezing point of heavy oil and biodiesel, when parking under the working conditions of heavy oil and biodiesel, as the engine temperature decreases, the remaining heavy oil and biodiesel will solidify in the fuel components, causing the entire pipeline to be blocked, affecting the next engine startup, and even causing damage to the fuel system. Currently, multi-fuel engines generally require converting heavy oil to light oil before shutting down, which takes a long time and wastes fuel. Therefore, when the present invention needs to stop for heavy oil and biodiesel, it can control the temperature of the fuel components in the fuel pipeline, and can also enable the engine to stop and start again normally.

[0125] Embodiment 2:

[0126] As Figure 2 shown, a temperature control system for a multi-fuel engine includes an electronic control unit (ECU) and a fuel type detection unit, an operating state detection unit, a temperature detection unit, a temperature control unit 1, an injector temperature control device 3, a fuel injection pump temperature control device 2 and a preset unit that are electrically connected to the electronic control unit respectively. The preset unit is used to preset the fuel type signal and the temperature threshold.

[0127] The fuel type detection unit is used to detect the current fuel type of the engine and transmit the corresponding fuel type signal to the electronic control unit; in this embodiment, the fuel type signal includes light diesel, biodiesel and heavy oil, and the fuel type detection unit can obtain the current fuel type through the current operating mode of the engine. Of course, it can also be input through the human-machine interaction unit.

[0128] The operation detection unit is used to detect whether the engine is in the running state and transmit the corresponding state signal to the electronic control unit; the operation detection unit may include a speed sensor, and judges whether the engine is currently in the running state or the shutdown state by detecting the engine speed.

[0129] The temperature detection unit includes a temperature sensor for detecting the fuel temperature and transmitting the corresponding fuel temperature signal to the electronic control unit.

[0130] The fuel injector temperature control device 3 includes two groups of fresh water heaters, two groups of fresh water coolers and a fresh water electric pump 30; specifically refer to Figure 2 , the fuel injector temperature control device 3 includes a fresh water heater 1, a fresh water heater 2, a fresh water cooler 1 and a fresh water cooler 2. The fresh water electric pump 30, the fresh water heater 1, the fresh water heater 2, the fresh water cooler 1, the fresh water cooler 2 and the fuel injector cooling cavity are connected to form a fresh water circulation loop. Among them, the fresh water heater 1, the fresh water heater 2, the fresh water cooler 1, the fresh water cooler 2 and the fresh water electric pump 30 are respectively electrically connected to the electronic control unit.

[0131] The fuel injection pump temperature control device 2 includes an engine oil heater, an engine oil cooler and an engine oil electric pump 20; specifically refer to Figure 2 , the engine oil heater, the engine oil cooler, the engine oil electric pump 20 and the fuel injection pump cooling cavity are connected to form an engine oil cooling loop, and the engine oil heater, the engine oil cooler and the engine oil electric pump 20 are respectively electrically connected to the electronic control unit.

[0132] The engine of the present invention is a multi-fuel engine, and the specific fuels are light diesel, biodiesel and heavy oil. Based on this, the temperature control unit 1 includes a light diesel temperature control unit, a biodiesel temperature control unit and a heavy oil temperature control unit, so as to adopt different temperature control methods for different fuels.

[0133] As Figure 1 shown, when the fuel type signal received by the temperature control unit 1 is light diesel, the light diesel temperature control unit is started.

[0134] The light diesel temperature control unit is used to transmit the corresponding shutdown signal to the electronic control unit to shut down the fuel injector temperature control device 3 and the fuel injection pump temperature control device 2 when the status signal is shutdown; specifically, all coolers, heaters and electric pumps are shut down.

[0135] The light diesel temperature control unit is used to judge whether the fuel temperature signal is greater than the preset temperature threshold when the status signal is running. If the fuel temperature signal is greater than the preset temperature threshold, a corresponding opening signal is generated to the electronic control unit to turn off the fresh water heater and the engine oil heater, and turn on the fresh water cooler, the fresh water electric pump 30, the engine oil cooler and the engine oil electric pump 20. Specifically, the fresh water cooler 1 can be turned on.

[0136] As Figure 1 shown, when the fuel type signal received by the temperature control unit 1 is biodiesel, the biodiesel temperature control unit is started.

[0137] The biodiesel temperature control unit is used to determine whether the fuel components need heat preservation when the status signal is shutdown. If the fuel components do not need heat preservation, it transmits the corresponding shutdown signal to the electronic control unit to turn off the fuel injector temperature control device 3 and the fuel injection pump temperature control device 2. If the fuel components need heat preservation, it transmits the corresponding heat preservation signal to the electronic control unit to turn on the fresh water heater, the engine oil heater, the fresh water electric pump 30 and the engine oil electric pump 20. Specifically, the fresh water heater 1 can be turned on. In addition, whether the fuel components need heat preservation can be input through the human-machine interaction unit or preset by the preset unit.

[0138] The biodiesel temperature control unit is used to determine whether the fuel temperature signal is greater than the preset temperature threshold when the status signal is running. If the fuel temperature signal is not greater than the preset temperature threshold, it transmits the corresponding shutdown signal to the electronic control unit to turn off the fuel injector temperature control device 3 and the fuel injection pump temperature control device 2. If the fuel temperature signal is greater than the preset temperature threshold, it transmits the generated corresponding turn-on signal to the electronic control unit to turn off the engine oil heater and the fresh water heater, and turn on the fresh water cooler, the engine oil cooler, the engine oil electric pump 20 and the fresh water electric pump 30. Specifically, the fresh water cooler 1 can be turned on.

[0139] As Figure 1 shown, when the fuel type signal received by the temperature control unit 1 is heavy oil, the heavy oil temperature control unit is started.

[0140] The heavy oil temperature control unit is used to determine whether the fuel components need heat preservation when the status signal is shutdown. If the fuel components do not need heat preservation, it transmits the corresponding shutdown signal to the electronic control unit to turn off the fuel injector temperature control device 3 and the fuel injection pump temperature control device 2. If the fuel components need heat preservation, it transmits the corresponding heat preservation signal to the electronic control unit to turn on all the fresh water heaters, the engine oil heaters, the fresh water electric pump 30 and the engine oil electric pump 20. Specifically, the fresh water heater 1 and the fresh water heater 2 can be turned on.

[0141] The heavy oil temperature control unit is used to determine whether the fuel temperature signal is greater than the preset temperature threshold when the status signal is running. If the fuel temperature signal is not greater than the preset temperature threshold, it transmits the corresponding shutdown signal to the electronic control unit to turn off the fuel injector temperature control device 3 and the fuel injection pump temperature control device 2. If the temperature signal is greater than the preset temperature threshold, it transmits the generated corresponding turn-on signal to the electronic control unit to turn off the engine oil heater and the fresh water heater, and turn on all the fresh water coolers, the engine oil coolers, the fresh water electric pump 30 and the engine oil electric pump 20. The fresh water coolers 1 and 2 can be turned on.

[0142] As Figure 2As shown in the figure, for the temperature control system of the multi-fuel engine of the present invention, the electronic control unit receives signals such as fuel type signal, fuel temperature signal, status signal, and fuel component heat preservation instruction. The electronic control unit transmits the fuel type signal, fuel temperature signal, status signal, and fuel component heat preservation instruction to the temperature control unit 1. The temperature unit controls the oil electric pump 20, oil cooler, oil heater, fresh water electric pump 30, fresh water heater 1, fresh water heater 2, fresh water cooler 1, and fresh water cooler 2 according to the current fuel type and the operating state of the engine, aiming to heat or cool the oil or fresh water passing through the fuel component cooling cavity, thereby controlling the temperature of the fuel components.

[0143] In view of the different fuels burned during the operation of the multi-fuel engine of the present invention, a specific temperature control scheme is used to ensure the normal operation of the engine. When the engine stops, due to the high viscosity and low pour point of heavy oil and biodiesel, when parking under the working conditions of heavy oil and biodiesel, as the engine temperature decreases, the remaining heavy oil and biodiesel will solidify in the fuel components, causing blockage of the entire pipeline, affecting the next engine start, and even causing damage to the fuel system. Currently, multi-fuel engines generally require converting heavy oil to light oil before stopping, which takes a long time and wastes fuel. Therefore, when the present invention needs to stop with heavy oil and biodiesel, it can control the temperature of the fuel components in the fuel pipeline, and can also enable the engine to stop and start again normally.

[0144] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent improvements such as a temperature control method and control system for a multi-fuel engine, etc., made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A temperature control method for a multi-fuel engine, the multi-fuel engine including a fuel component temperature regulating device, characterized in that, The temperature control method includes the following steps: Obtain the current fuel type of the engine; Judge whether the fuel type matches the preset type; If it matches, then judge whether the engine is in the running state or the shutdown state; If the engine is in the shutdown state, generate a corresponding shutdown temperature control signal; According to the shutdown temperature control signal, turn off the fuel component temperature control device; or; according to the shutdown temperature control signal, judge whether the fuel component needs heat preservation; If the fuel component does not need heat preservation, turn off the fuel component temperature control device; if the fuel component needs heat preservation, generate a corresponding heat preservation signal, and according to the heat preservation signal, control the fuel component temperature control device to turn off the cooling function and turn on the heating function.

2. The temperature control method of the multi-fuel engine according to claim 1, characterized in that The step of judging whether the fuel type matches the preset type includes: judging whether the fuel type matches the preset light diesel type; The step of if it matches, then judge whether the engine is in the running state or the shutdown state includes: if the fuel type matches the light diesel type, generate a corresponding light diesel temperature control signal, and then judge whether the engine is in the running state or the shutdown state; The step of if the engine is in the shutdown state, generate a corresponding shutdown temperature control signal includes: if the engine is in the shutdown state, then generate a corresponding light diesel shutdown temperature control signal according to the light diesel temperature control signal; The step of turning off the fuel component temperature control device according to the shutdown temperature control signal is: turning off the fuel component temperature control device according to the light diesel shutdown temperature control signal.

3. The temperature control method of the multi-fuel engine according to claim 1, characterized in that The step of judging whether the fuel type matches the preset type includes: judging whether the fuel type matches the preset biodiesel type; The step of if it matches, then judge whether the engine is in the running state or the shutdown state includes: if the fuel type matches the preset biodiesel type, generate a corresponding biodiesel temperature control signal, and then judge whether the engine is in the running state or the shutdown state; The step of if the engine is in the shutdown state, generate a corresponding shutdown temperature control signal includes: if the engine is in the shutdown state, then generate a corresponding biodiesel shutdown temperature control signal according to the biodiesel temperature control signal; The step of judging whether the fuel component needs heat preservation according to the shutdown temperature control signal is: judging whether the fuel component needs heat preservation according to the biodiesel shutdown temperature control signal; The step of if the fuel component needs heat preservation, generate a corresponding heat preservation signal is: if the fuel component needs heat preservation, generate a corresponding biodiesel heat preservation signal; The step of controlling the fuel component temperature control device to turn off the cooling function and turn on the heating function according to the heat preservation signal is: controlling the fuel component temperature control device to turn off the cooling function and turn on a partial heating function according to the biodiesel heat preservation signal.

4. The temperature control method of the multi-fuel engine according to claim 1, characterized in that The step of judging whether the fuel type matches the preset type includes: judging whether the fuel type matches the preset heavy oil type; The step of, if a match is found, further determining whether the engine is in a running state or a stopped state includes: if the fuel type matches the preset heavy oil type, generating a corresponding heavy oil temperature control signal, and then determining whether the engine is in a running state or a stopped state; The step of, if the engine is in a stopped state, generating a corresponding stopped state temperature control signal includes: if the engine is in a stopped state, further generating a corresponding heavy oil stopped state temperature control signal according to the heavy oil temperature control signal; The step of, according to the stopped state temperature control signal, closing the temperature regulating device of the fuel components is: according to the heavy oil stopped state temperature control signal, determining whether the fuel components need heat preservation; The step of, if the fuel components need heat preservation, generating a corresponding heat preservation signal is: if the fuel components need heat preservation, generating a corresponding heavy oil heat preservation signal; The step of, according to the heat preservation signal, controlling the temperature regulating device of the fuel components to close the cooling function and turn on the heating function is: according to the heavy oil heat preservation signal, controlling the temperature regulating device of the fuel components to close the cooling function and turn on all heating functions.

5. The temperature control method of a multi-fuel engine according to claim 1, characterized in that, The step of, if the engine is in a stopped state, generating a corresponding stopped state temperature control signal further includes: if the engine is in a running state, generating a corresponding running state temperature control signal; The step of, according to the stopped state temperature control signal, closing the temperature regulating device of the fuel components further includes: according to the running state temperature control signal, determining whether the fuel temperature is too high; If the fuel temperature is too high, generating a corresponding cooling signal; If the fuel temperature is not too high, closing the temperature regulating device of the fuel components; According to the cooling signal, controlling the temperature regulating device of the fuel components to turn off the heating function, turn on the cooling function, and then determining whether the fuel temperature is too high.

6. The temperature control method of a multi-fuel engine according to claim 5, characterized in that, When the fuel type matches the preset heavy oil type, according to the cooling signal, controlling the temperature regulating device of the fuel components to turn off the heating function, turn on all cooling functions, and then determining whether the fuel temperature is too high; When the fuel type matches the preset light diesel oil type or the preset biodiesel, according to the cooling signal, controlling the temperature regulating device of the fuel components to turn off the heating function, turn on partial cooling functions, and then determining whether the fuel temperature is too high.

7. A temperature control system for a multi-fuel engine, characterized in that, It includes an electronic control unit and a fuel type detection unit, a running state detection unit, a temperature detection unit, a temperature control unit, an injector temperature control device, and a fuel injection pump temperature control device that are respectively electrically connected to the electronic control unit; The fuel type detection unit is used to detect the current fuel type of the engine and transmit a corresponding fuel type signal to the electronic control unit; The running state detection unit is used to detect whether the engine is in a running state and transmit a corresponding state signal to the electronic control unit; The temperature detection unit is used to detect the fuel temperature and transmit a corresponding fuel temperature signal to the electronic control unit; The injector temperature control device includes two groups of fresh water heaters, two groups of fresh water coolers, and a fresh water electric pump; The fuel injection pump temperature control device includes an engine oil heater, an engine oil cooler, and an engine oil electric pump; The electronic control unit transmits fuel type signals, status signals, and fuel temperature signals to the temperature control unit. The temperature control unit transmits corresponding temperature control signals to the electronic control unit according to the received fuel type signals, status signals, and fuel temperature signals to control the fuel injector temperature control device and the fuel injection pump temperature control device.

8. The temperature control system of the multi-fuel engine according to claim 7, characterized in that, The temperature control unit includes a light diesel oil temperature control unit. When the fuel type signal received by the temperature control unit is light diesel oil, the light diesel oil temperature control unit is started; The light diesel oil temperature control unit is used to transmit a corresponding shutdown signal to the electronic control unit to shut down the fuel injector temperature control device and the fuel injection pump temperature control device when the status signal is shutdown; The light diesel oil temperature control unit is used to judge whether the fuel temperature signal is greater than a preset temperature threshold when the status signal is running. If the fuel temperature signal is greater than the preset temperature threshold, a corresponding opening signal is generated and transmitted to the electronic control unit to shut down the fresh water heater and the engine oil heater, and to open a group of the fresh water cooler, the fresh water electric pump, the engine oil cooler, and the engine oil electric pump.

9. The temperature control system of the multi-fuel engine according to claim 7, characterized in that, The temperature control unit includes a biodiesel temperature control unit. When the fuel type signal received by the temperature control unit is biodiesel, the biodiesel temperature control unit is started; The biodiesel temperature control unit is used to judge whether the fuel components need heat preservation when the status signal is shutdown. If the fuel components do not need heat preservation, a corresponding shutdown signal is transmitted to the electronic control unit to shut down the fuel injector temperature control device and the fuel injection pump temperature control device. If the fuel components need heat preservation, a corresponding heat preservation signal is transmitted to the electronic control unit to open a group of the fresh water heater, the engine oil heater, the fresh water electric pump, and the engine oil electric pump; The biodiesel temperature control unit is used to judge whether the fuel temperature signal is greater than a preset temperature threshold when the status signal is running. If the fuel temperature signal is not greater than the preset temperature threshold, a corresponding shutdown signal is transmitted to the electronic control unit to shut down the fuel injector temperature control device and the fuel injection pump temperature control device; If the fuel temperature signal is greater than the preset temperature threshold, a corresponding opening signal is generated and transmitted to the electronic control unit to shut down the engine oil heater and the fresh water heater, and to open the fresh water cooler, the engine oil cooler, the engine oil electric pump, and the fresh water electric pump.

10. The temperature control system of the multi-fuel engine according to claim 7, characterized in that, The temperature control unit includes a heavy oil temperature control unit. When the fuel type signal received by the temperature control unit is heavy oil, the heavy oil temperature control unit is started; The heavy oil temperature control unit is used to judge whether the fuel components need heat preservation when the status signal is shutdown. If the fuel components do not need heat preservation, a corresponding shutdown signal is transmitted to the electronic control unit to shut down the fuel injector temperature control device and the fuel injection pump temperature control device. If the fuel components need heat preservation, a corresponding heat preservation signal is transmitted to the electronic control unit to open two groups of the fresh water heater, the engine oil heater, the fresh water electric pump, and the engine oil electric pump; The heavy oil temperature control unit is used to determine whether the fuel temperature signal is greater than a preset temperature threshold when the status signal is in the running state. If the fuel temperature signal is not greater than the preset temperature threshold, a corresponding closing signal is transmitted to the electronic control unit to close the fuel injector temperature control device and the fuel injection pump temperature control device; if the temperature signal is greater than the preset temperature threshold, a corresponding opening signal is generated and transmitted to the electronic control unit to close the oil heater and the fresh water heater, and to open the two groups of fresh water coolers, the oil cooler, the fresh water electric pump and the oil electric pump.

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