A range extending engine flash boiling spray device and control method

Abstract

The present application belongs to the technical field of range extending engine control, and particularly relates to a range extending engine flash boiling spray device and a control method. The engine flash boiling control device and the control method provided by the present application can heat gasoline in the device through a heater, and can heat the gasoline through a heat exchanger using cooling liquid. The energy consumption caused by directly using electric heating is reduced, and after the gasoline is heated, the gasoline flows into a high-pressure oil pump to realize flash boiling spray of the fuel, so that the device can realize smaller droplet size, faster gasoline evaporation rate and violent mixing effect between gasoline and air, realize ultra-lean combustion, greatly improve thermal efficiency and reduce emissions; at the same time, the rapid cooling of the cooling liquid is realized. The present application adjusts two heating modes to complete the heating of gasoline by calculating the required temperature of the range extending engine under different loads in a specific working condition when generating electricity, and realizes the flash boiling spray of the range extending engine under different loads in a specific working condition.

Description

Technical Field

[0001] This invention belongs to the field of range extender engine control technology, specifically relating to a range extender engine flash boiling spray device and control method. Background Technology

[0002] In the design of the core combustion system of an engine, fuel atomization is a key technology for achieving clean and efficient combustion. Achieving efficient fuel atomization, thus better mixing fuel and air into a homogeneous gas, is crucial for energy conservation and emission reduction in the combustion system. Research shows that appropriately increasing the fuel temperature to achieve fuel flash-boiling spray can significantly improve fuel atomization and evaporation effects under lower injection pressure conditions, thereby reducing gasoline engine exhaust emissions and improving fuel economy.

[0003] The current mainstream method for heating fuel to achieve flash boiling spray is to directly heat the fuel using electric heating. This is used in thermal management systems to rapidly raise the temperature of the fuel to solve cold start problems and quickly warm up the engine, as well as in electric heated fuel injectors. However, heating gasoline electrically consumes a lot of energy, thus diminishing the emission reduction benefits of flash boiling spray.

[0004] Furthermore, for range-extending engines, existing technology lacks a device that can achieve fuel flash boiling spray by controlling gasoline temperature under different loads during specific operating conditions during power generation. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology, which directly uses electric heating to heat fuel, resulting in large energy consumption, and fails to achieve fuel flash boiling spray under different loads and specific operating conditions during power generation. Therefore, the present invention provides a range extender engine flash boiling spray device and control method.

[0006] A range extender engine flash spray device includes a heat exchanger, a proportional valve, a three-way valve, a heater, and a high-pressure oil pump;

[0007] The first input end of the heat exchanger is connected to the oil inlet, and the first output end is connected to the input end of the three-way valve.

[0008] The input end of the proportional valve is connected to the coolant inlet, and the output end is connected to the second input end of the heat exchanger; the second output end of the heat exchanger is connected to the coolant outlet.

[0009] The first output terminal of the three-way valve is connected to the input terminal of the high-pressure oil pump;

[0010] The input end of the heater is connected to the second output end of the three-way valve, and the output end is connected to the input end of the high-pressure oil pump.

[0011] The output end of the high-pressure oil pump is connected to the oil outlet.

[0012] Furthermore, it also includes an electronic control unit, which is connected to and controls the proportional valve, the three-way valve and the heater respectively.

[0013] Furthermore, it also includes an oil temperature sensor, which is installed at the oil outlet and connected to the electronic control unit.

[0014] Furthermore, it also includes a cylinder pressure sensor, which is installed in the combustion chamber of the range extender engine and connected to the electronic control unit.

[0015] Furthermore, the heater includes a heating wire for heating a heating medium for heating gasoline.

[0016] Furthermore, the heating medium is methyl silicone oil.

[0017] Furthermore, it also includes a temperature controller, which can monitor the gasoline temperature inside the heater, and its output is connected to the heating wire via a silicon controlled rectifier power regulator; the temperature controller is connected to the electronic control unit.

[0018] Furthermore, it also includes a first check valve, a second check valve, and a third check valve; the input end of the first check valve is connected to the second output end of the heat exchanger, and the output end is connected to the coolant outlet; the input end of the second check valve is connected to the first output end of the three-way valve, and the output end is connected to the input end of the high-pressure oil pump; the input end of the third check valve is connected to the output end of the heater, and the output end is connected to the input end of the high-pressure oil pump.

[0019] A control method for a flash spray device in a range extender engine includes the following steps:

[0020] Step S1: Determine the required overheat for the current power generation operation of the range extender engine;

[0021] Step S2: Collect the cylinder pressure of the range extender engine and calculate the required temperature based on the required superheat.

[0022] Step S3: Preset the flash boiling critical temperature and additional heating temperature;

[0023] Step S4.1: If the required temperature is less than the flash boiling critical temperature, close the proportional valve and connect the input end of the three-way valve to its first output end;

[0024] Step S4.2: If the required temperature is between the critical flash boiling temperature and the additional heating temperature, monitor the oil outlet temperature and adjust the opening of the proportional valve to make the oil outlet temperature consistent with the required temperature; the input end of the three-way valve is connected to its first output end;

[0025] Step S4.3: If the required temperature is greater than the additional heating temperature, open the proportional valve; connect the output end of the three-way valve to its second output end, monitor the oil outlet temperature, start and adjust the heater so that the oil outlet temperature is consistent with the required temperature.

[0026] Furthermore, the flash boiling critical temperature is 40°C, and the additional heating temperature is 80°C.

[0027] Beneficial effects:

[0028] 1. This invention provides an engine flash boiling control device and method. Gasoline can be heated in the device via a heater or by coolant via a heat exchanger, reducing energy consumption from direct electric heating. After heating, the gasoline flows into a high-pressure fuel pump to achieve fuel flash boiling spray. This allows the device to achieve smaller mist particle size, a faster gasoline evaporation rate, and vigorous mixing with air, achieving ultra-lean combustion, greatly improving thermal efficiency and reducing emissions; simultaneously, it enables rapid cooling of the coolant. This invention calculates the required temperature under different loads during specific operating conditions of a range-extended engine and adjusts the two heating methods to heat the gasoline, achieving flash boiling spray under different loads during constant operating conditions of a range-extended engine.

[0029] 2. This invention, through the setting of an electronic control unit, monitors cylinder pressure and oil temperature at the outlet in real time, connects and controls the operation of the proportional valve, three-way valve and heater, and realizes gasoline temperature control under different loads under specific operating conditions of the range extender engine, thereby achieving flash boiling spray.

[0030] 3. This invention achieves precise control of gasoline temperature inside the heater through the setting of a temperature controller; and ensures safe, efficient, and rapid heating of gasoline inside the heater through the setting of a silicon controlled rectifier power regulator, heating wire, and heating medium; and ensures the reliability of the flash boiling spray device by setting a first one-way valve, a second one-way valve, and a third one-way valve. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of the device of the present invention;

[0032] Figure 2 This is a flowchart of the control method of the present invention;

[0033] Figure 3 This is a table showing the saturated vapor pressure of gasoline at different temperatures according to the present invention. Detailed Implementation

[0034] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] Reference Figure 1 As shown, this embodiment provides a range extender engine flash spray device, including a heat exchanger, a proportional valve, a three-way valve, a heater, and a high-pressure oil pump;

[0036] The first input end of the heat exchanger is connected to the oil inlet, and the first output end is connected to the input end of the three-way valve.

[0037] The input end of the proportional valve is connected to the coolant inlet, and the output end is connected to the second input end of the heat exchanger; the second output end of the heat exchanger is connected to the coolant outlet; the proportional valve is an electric proportional two-way valve.

[0038] The first output terminal of the three-way valve is connected to the input terminal of the high-pressure oil pump; the three-way valve is an electric three-way valve.

[0039] The input end of the heater is connected to the second output end of the three-way valve, and the output end is connected to the input end of the high-pressure oil pump.

[0040] The output end of the high-pressure oil pump is connected to the oil outlet.

[0041] This embodiment provides an engine flash boiling control device and control method. Gasoline can be heated in the device by a heater or by a heat exchanger using coolant, which reduces the energy consumption caused by direct electric heating. After the gasoline is heated, it flows into a high-pressure oil pump to achieve fuel flash boiling spray. Thus, the device can achieve smaller mist particle size, faster gasoline evaporation rate and intense mixing effect with air, realize ultra-lean combustion, greatly improve thermal efficiency and reduce emissions.

[0042] It also includes an Electronic Control Unit (ECU), which is connected to and controls the proportional valve, the three-way valve, and the heater. Through the ECU's settings, cylinder pressure and outlet fuel temperature are monitored in real time, and the operation of the proportional valve, three-way valve, and heater is controlled to achieve gasoline temperature control under different loads and specific operating conditions of the range-extended engine, thereby realizing flash boiling spray. The proportional valve sends an opening feedback signal to the ECU, and the ECU sends a control signal to the proportional valve. The ECU also sends a control signal to the three-way valve.

[0043] It also includes an oil temperature sensor, which is installed at the oil outlet and connected to the electronic control unit.

[0044] It also includes a cylinder pressure sensor, which is installed in the combustion chamber of the range extender engine and connected to the electronic control unit.

[0045] The heater includes a heating wire for heating a heating medium, which is used to heat gasoline. The heating medium is methyl silicone oil.

[0046] It also includes a temperature controller, which can monitor the gasoline temperature inside the heater, and its output is connected to the heating wire through a silicon controlled rectifier power regulator; the temperature controller is connected to the electronic control unit.

[0047] Specifically, the heat exchanger is a plate heat exchanger. Gasoline flows in from its first inlet and flows out from its first outlet, while coolant flows in from its second inlet and flows out from its second outlet. Gasoline and coolant exchange heat within the plate heat exchanger, thereby enabling the coolant to heat the gasoline while simultaneously accelerating its own cooling.

[0048] The temperature controller receives temperature control signals from the electronic control unit, monitors the gasoline temperature inside the heater in real time, and controls the thyristor power regulator to adjust the heating power of the resistance wire, thereby heating the heating medium. The heat from the heating medium is conducted to the gasoline inside the heater, completing the heating of the gasoline. The resistance wire is a DC resistance wire. The heating medium is methyl silicone oil, which has good heat resistance, electrical insulation, and thermal conductivity, enabling reliable and efficient heating.

[0049] The cylinder pressure sensor is a water-cooled type, featuring high sensitivity and thermodynamic characteristics. It is installed in the combustion chamber of the range extender engine, monitoring the pressure signal within the combustion chamber, and connected to the electronic control unit via a charge amplifier.

[0050] It also includes a first one-way valve, a second one-way valve, and a third one-way valve; the input end of the first one-way valve is connected to the second output end of the heat exchanger, and the output end is connected to the coolant outlet; the input end of the second one-way valve is connected to the first output end of the three-way valve, and the output end is connected to the input end of the high-pressure oil pump; the input end of the third one-way valve is connected to the output end of the heater, and the output end is connected to the input end of the high-pressure oil pump. The use of the first, second, and third one-way valves ensures unidirectional flow of gasoline and coolant within the device, thus ensuring the reliability of the flash-boiling spray device.

[0051] Reference Figure 2 As shown, this embodiment also provides a control method for a range-extender engine flash boiling spray device, which employs the above-mentioned range-extender engine flash boiling spray device and includes the following steps:

[0052] Step S1: Determine the required overheat for the current power generation operation of the range extender engine;

[0053] Step S2: Collect the cylinder pressure of the range extender engine and calculate the required temperature based on the required superheat.

[0054] Step S3: Preset the flash boiling critical temperature and additional heating temperature;

[0055] Step S4.1: If the required temperature is less than the flash boiling critical temperature, close the proportional valve and connect the input end of the three-way valve to its first output end;

[0056] Step S4.2: If the required temperature is between the critical flash boiling temperature and the additional heating temperature, monitor the oil outlet temperature and adjust the opening of the proportional valve to make the oil outlet temperature consistent with the required temperature; the input end of the three-way valve is connected to its first output end;

[0057] Step S4.3: If the required temperature is greater than the additional heating temperature, open the proportional valve; connect the output end of the three-way valve to its second output end, monitor the oil outlet temperature, start and adjust the heater so that the oil outlet temperature is consistent with the required temperature.

[0058] Preferably, in this embodiment, the flash boiling critical temperature is 40°C and the additional heating temperature is 80°C.

[0059] Specifically, refer to Figure 3 As shown, the saturated vapor pressure of gasoline at different temperatures is first collected and denoted as Ps.

[0060] The superheat is the ratio of ambient gas pressure Pa to gasoline saturated vapor pressure Ps (Pa / Ps). In this embodiment, the ambient gas pressure Pa is the pressure value monitored by the cylinder pressure sensor.

[0061] According to the physical properties of gasoline at different temperatures, the spray conditions are divided into three regions: cold spray (Pa / Ps > 1, liquid spray), transitional flash boiling spray (0.3 < Pa / Ps < 1), and flare flash boiling spray (Pa / Ps < 0.3).

[0062] In step S1, according to the results of pre-test on the test bench, the magnitude of the required superheat degree Pa / Ps under the current working condition can be determined. Specifically, pre-test on the test bench the effects of various spray patterns on fuel economy improvement and emission reduction at different loads under a specific rotational speed, and find the optimal spray pattern through testing, and preset the corresponding superheat degree value in the electronic control unit.

[0063] In step S2, collect the cylinder pressure Pa of the range extender engine, solve the ratio with the required superheat degree Pa / Ps to obtain the saturated vapor pressure Ps, and look up the table to obtain the corresponding required temperature t.

[0064] In step S3, in this embodiment, the flash boiling critical temperature is preset to 40°C, and the additional heating temperature is 80°C. According to the properties of gasoline, when the temperature is lower than 40°C, the saturated vapor pressure Ps of gasoline is relatively small, and the ambient pressure Pa in the cylinder can easily exceed it, making the superheat degree greater than 1. Therefore, 40°C is set as the flash boiling critical temperature; at the same time, the external temperature of the engine coolant is generally about 90°C, and the maximum temperature for heating fuel with coolant is generally 80°C. Higher temperatures need to be achieved by electric heating. Therefore, 80°C is set as the additional heating temperature.

[0065] In step S4.1, when the required temperature t is less than 40°C, the working state of the device is cold spray, and the electronic control unit controls the heat exchanger and the heater not to work, and the gasoline passes directly through.

[0066] In step S4.2, when the required temperature t is between 40°C and 80°C, the working state of the device is flash boiling spray. When the required temperature t is in this temperature range, the heat exchanger can complete the heating by working. The electronic control unit controls the heat exchanger to work and the heater not to work; at this time, the electronic controller receives the temperature signal of the oil temperature sensor, and the electronic control device controls the heating efficiency of the heat exchanger through the opening of the proportional valve, so as to control the heating temperature of the gasoline.

[0067] In step S4.3, when the required temperature t exceeds 80°C, the working state of the device is flash boiling spray, and the heat exchanger and the heater need to work simultaneously to complete the heating of the gasoline. The electronic control unit controls the heat exchanger and the heater to work; at this time, the electronic controller receives the temperature signal of the oil temperature sensor and outputs a temperature control signal to the temperature controller.

[0068] Working principle: Based on the superheat requirements of the range extender engine at different speeds, the control requirements of gasoline temperature, i.e. the required temperature t, are calculated. The opening of the coolant proportional valve and the power of the electric heater are then adjusted to control the heating effect, thereby achieving the flash boiling spray effect under the condition of constant speed and variable load, and realizing the purpose of higher combustion efficiency and lower emissions.

[0069] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several equivalent substitutions or obvious modifications can be made without departing from the concept of the present invention, and all such modifications, achieving the same performance or purpose, should be considered within the scope of protection of the present invention.

Claims

1. A control method of a flash boiling spray device of a range extended engine, characterized by, The flash boiling spray device of the extended range engine comprises a heat exchanger, a proportional valve, a three-way valve, a heater, and a high-pressure oil pump; the first input end of the heat exchanger is connected to an oil inlet, and the first output end is connected to the input end of the three-way valve; the input end of the proportional valve is connected to a cooling liquid inlet, and the output end is connected to the second input end of the heat exchanger; the second output end of the heat exchanger is connected to a cooling liquid outlet; the first output end of the three-way valve is connected to the input end of the high-pressure oil pump; the input end of the heater is connected to the second output end of the three-way valve, and the output end is connected to the input end of the high-pressure oil pump; and the output end of the high-pressure oil pump is connected to an oil outlet. The control method comprises the following steps: Step S1: determining the required superheat degree of the power generation working condition of the current extended range engine; Step S2: collecting the cylinder pressure of the extended range engine and calculating the required temperature according to the required superheat degree; Step S3: presetting a flash boiling critical temperature and an additional heating temperature; Step S4.1: if the required temperature is less than the flash boiling critical temperature, the proportional valve is closed, and the input end of the three-way valve is connected to the first output end thereof; Step S4.2: if the required temperature is between the flash boiling critical temperature and the additional heating temperature, the oil outlet temperature is monitored, the opening degree of the proportional valve is adjusted so that the oil outlet temperature is consistent with the required temperature, and the input end of the three-way valve is connected to the first output end thereof; Step S4.3: if the required temperature is greater than the additional heating temperature, the proportional valve is opened, the output end of the three-way valve is connected to the second output end thereof, the oil outlet temperature is monitored, and the heater is started and adjusted so that the oil outlet temperature is consistent with the required temperature.

2. The control method of the flash boiling spray device of the range extended engine according to claim 1, characterized in that, The flash boiling critical temperature is 40℃, and the additional heating temperature is 80℃.

3. A flash boiling spray device for a range extended engine, characterized in that, The flash boiling spray device of the extended range engine is used for realizing the flash boiling spray control according to the control method of claim 1, and comprises a heat exchanger, a proportional valve, a three-way valve, a heater, and a high-pressure oil pump.

4. The flash boiling spray device of claim 3, wherein, An electronic control unit is further included, which is connected to and controls the proportional valve, the three-way valve, and the heater.

5. The flash boiling spray device of claim 4, wherein, An oil temperature sensor is further included, which is installed at the oil outlet and connected to the electronic control unit.

6. The flash boiling spray device of claim 4, wherein, A cylinder pressure sensor is further included, which is installed in the combustion chamber of the extended range engine and connected to the electronic control unit.

7. The flash boiling spray device of claim 4, wherein, The heater comprises a heating wire, which is used for heating a heating medium, and the heating medium is used for heating gasoline.

8. The flash boiling spray device of a range extended engine according to claim 7, wherein, The heating medium is methyl silicone oil.

9. The flash boiling spray device of claim 7, wherein, A temperature controller is further included, which can monitor the gasoline temperature in the heater, and the output end is connected to the heating wire through a thyristor power regulator; and the temperature controller is connected to the electronic control unit.

10. The flash boiling spray device of claim 3, wherein, First, second, and third one-way valves are further included; the input end of the first one-way valve is connected to the second output end of the heat exchanger, and the output end is connected to the cooling liquid outlet; the input end of the second one-way valve is connected to the first output end of the three-way valve, and the output end is connected to the input end of the high-pressure oil pump; and the input end of the third one-way valve is connected to the output end of the heater, and the output end is connected to the input end of the high-pressure oil pump.

Images