Natural gas internal combustion engine fuel injector heating method

Abstract

The invention relates to the field of natural gas internal combustion engine fuel injectors, and particularly discloses a natural gas internal combustion engine fuel injector heating method. Comprising the following steps that S1, the outer side of the ejector is sleeved with a heater, the heater is connected into an ECU to be controlled, and the ECU is controlled in a constant electric mode; s2, presetting a low-temperature parameter value, and starting a heater when the temperature is less than or equal to the low-temperature parameter value and the vehicle is unlocked; and S3, the temperature of the ejector is collected after the heater is started, the temperature is fed back to the ECU, and the heater is closed after the temperature is higher than the low-temperature parameter value. The problems that the ejector is difficult to start in a low-temperature environment, the response speed is low when coil spontaneous heating is adopted, and the ejector is prone to being burnt out are solved.

Description

Technical Field

[0001] The invention relates to the field of natural gas internal combustion engine fuel injectors, and in particular to a natural gas internal combustion engine fuel injector heating method. Background Art

[0002] Natural gas is a multi-component mixed gas, the main component of which is alkane, of which methane accounts for the vast majority, and there are also small amounts of ethane, propane and butane, etc. In addition, it generally contains impurities such as hydrogen sulfide, carbon dioxide, nitrogen and water vapor. When the ambient temperature reaches minus 10℃ or even lower, the presence of the above impurities will cause the injector to be unable to open or difficult to open, thereby causing difficulty in cold starting of the natural gas engine at low temperatures. When the natural gas engine is used in a vehicle, it will cause the vehicle to be unable to start in a cold environment, especially when the driver is driving the vehicle on highways, mountainous areas, etc., far away from the city, where rescue is inconvenient and it is difficult to abandon the vehicle, and the vehicle has been unable to start, which will also bring serious danger to the driver. Therefore, this is a fatal defect when the natural gas engine is used in automobiles.

[0003] In view of the above defects, the common practice at present is to start the solenoid valve coil of the control armature in the injector to heat up the solenoid valve coil for preheating when the injector cannot be opened or is difficult to open due to low temperature. However, the solenoid valve coil itself is not designed for heating, and only using the heat generated during its long-term operation for preheating also leads to low heating efficiency. Secondly, when the solenoid valve coil is used for preheating, the coil is easy to burn out due to the open loop control without feedback. Summary of the invention

[0004] The present invention is intended to provide a method for heating a fuel injector of a natural gas internal combustion engine, so as to solve the problems that the injector is difficult to start in a low temperature environment, and has a slow response speed and is easy to burn out when using coil self-heating.

[0005] To achieve the above object, the present invention adopts the following technical solution: a method for heating a fuel injector of a natural gas internal combustion engine, comprising the following steps:

[0006] S1, a heater is installed outside the injector and connected to the ECU for control. The ECU is normally powered.

[0007] S2, preset low temperature parameter value, and the heater is started when the temperature is less than or equal to the low temperature parameter value and the vehicle is unlocked;

[0008] S3, after the heater is started, the temperature of the injector is collected and fed back to the ECU, and the heater is turned off when the temperature is higher than the low temperature parameter value.

[0009] The low temperature parameter value in this scheme refers to the temperature below which the injector will fail to start. The low temperature parameter value is determined through experiments based on the performance of the corresponding injector.

[0010] The beneficial effects of this program are:

[0011] 1. This solution adds a heater on the outside of the injector. In a low temperature environment, when it is detected that the vehicle is unlocked and needs to be started, the heater can quickly heat the injector, and the heating efficiency is much higher than the solenoid valve coil of the injector.

[0012] 2. During the heating process, the temperature of the injector can be collected in real time, and the heater can be turned off in time when the temperature reaches the temperature at which the injector can be started, effectively saving energy.

[0013] 3. The heater sleeve in this solution is installed on the outside of the injector, so there is no need to change the structure of the injector when using the method of this solution for heating. Therefore, this solution can directly use the existing injector for modification, omitting the process of redesigning and producing the injector, effectively shortening the period required for application, reducing costs, and the injectors in existing vehicles can also adopt the heating method of this solution, which has a wider range of applications.

[0014] Furthermore, S1 sets a heater sleeve on the injector common rail.

[0015] The beneficial effects of this solution are: when the hydrogen flows through the injector common rail, it is heated, the heating speed is fast, and it can ensure that the hydrogen entering the injector maintains a certain temperature, avoiding the temperature of the injector from decreasing again.

[0016] Furthermore, S1 sets a heater sleeve on the nozzle of the injector.

[0017] The beneficial effect of this solution is that the sprayed hydrogen is heated, and the energy consumption is lower.

[0018] Further, S2 activates the solenoid valve coil of the injector while activating the heater.

[0019] The beneficial effect of this solution is that the solenoid valve coil is used as an auxiliary heating structure for self-heating, which effectively improves the heating speed.

[0020] Furthermore, in S1-S3, the control method of the ECU adopts the form of PWM signal.

[0021] The beneficial effect of this solution is that the ECU in this solution can achieve fast and high-precision control of the start and stop of the heater, making the heating more efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1This is a flow chart of Embodiment 1 of the present invention;

[0023] Figure 2 This is a control logic diagram of Embodiment 1 of the present invention;

[0024] Figure 3 is a partial cross-sectional view of the heater used in Example 1 of the present invention;

[0025] Figure 4 It is a partial cross-sectional view of the heater used in Example 2 of the present invention. DETAILED DESCRIPTION

[0026] The following is further described in detail through specific implementation methods:

[0027] The reference numerals in the drawings of the specification include: solenoid valve coil 1, common rail 11, nozzle 12, injector control interface 13, heating element 2, temperature sensor 21, heater signal interface 3, handle 4.

[0028] Example 1

[0029] Example 1 is basically as Figure 1 and Figure 2 As shown, a method for heating a fuel injector of a natural gas internal combustion engine comprises the following steps:

[0030] S1, a heater is installed outside the common rail of the injector, and the heater and the injector are connected to the ECU for control. Specifically, the heater is connected through the heater signal interface, and the injector is connected through the injector signal interface. The control mode of the ECU adopts the PWM signal form, and the ECU is set to normal power control;

[0031] S2, lowering the temperature of the injector, determining the low temperature value at which the injector cannot be started, and presetting it in the ECU as a low temperature parameter value, detecting the temperature of the injector through a temperature sensor in the heater, and transmitting the detected temperature value to the ECU, and when the above temperature is less than or equal to the low temperature parameter value and the vehicle is unlocked, the ECU controls the solenoid valve coils of the heater and the injector to start;

[0032] S3, after the heater is started, the temperature of the injector is collected and fed back to the ECU, and the heater is turned off when the temperature is higher than the low temperature parameter value.

[0033] The heater used in step S1 is as follows: Figure 3As shown, it includes a ring-shaped heating element 2 and a handle 4, wherein the heating element 2 is provided with a PTC thermal resistance wire, the handle 4 is connected to the heating element 2, a temperature sensor 21 is provided on the side of the heating element 2 facing the injector, a heater signal interface 3 is provided on the handle 4, the temperature sensor 21 is connected to the heater signal interface 3, the temperature signal fed back by the temperature sensor 21 is connected to the ECU through the heater signal interface 3, and the heating control signal sent by the ECU is connected to the heating element 2.

[0034] Example 2

[0035] On the basis of Example 1, Figure 4 As shown, step S1 in this embodiment sets the heater sleeve on the nozzle 12 of the injector, and the heater used at this time may not be provided with a handle 4, and the heater signal interface 3 can be directly set on the heating element 2. Apart from this, the control process in this embodiment is the same as that in Example 1.

[0036] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for heating a fuel injector of a natural gas internal combustion engine, characterized in that: The following steps are involved: S1, a heater is installed outside the injector and connected to the ECU for control. The ECU is normally powered. S2, preset low temperature parameter value, and the heater is started when the temperature is less than or equal to the low temperature parameter value and the vehicle is unlocked; S3, after the heater is started, the temperature of the injector is collected and fed back to the ECU, and the heater is turned off when the temperature is higher than the low temperature parameter value.

2. A method for heating a natural gas internal combustion engine fuel injector according to claim 1, characterized in that: S1 installs the heater sleeve on the injector common rail.

3. The method for heating a natural gas internal combustion engine fuel injector according to claim 1, characterized in that: S1 sets the heater sleeve on the nozzle of the injector.

4. A method for heating a natural gas internal combustion engine fuel injector according to claim 2 or 3, characterized in that: S2 activates the injector solenoid valve coil while activating the heater.

5. A method for heating a natural gas internal combustion engine fuel injector according to claim 4, characterized in that: In S1-S3, the ECU is controlled in the form of PWM signals.

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