CN102235255B - Method and system for solving problem of difficulty in opening of compressed natural gas (CNG) nozzle under low-temperature environment - Google Patents

Abstract

The invention discloses a method and system for solving the difficulty of opening a CNG nozzle in a low temperature environment, which is used in a compressed natural gas engine. The method includes the following steps: Step 1, the controller in the compressed natural gas engine The intake air temperature and the cooling water temperature determine whether the ambient temperature reaches the set low temperature condition; if the set low temperature condition is reached, step 2 is performed, otherwise continue to judge the ambient temperature; step 2, the controller drives the CNG nozzle at a high frequency instantaneously, The driving time corresponds to the ambient temperature. In the present invention, by adding a low temperature discrimination method, the controller drives the CNG nozzle at high frequency instantaneously under low temperature conditions, so that the CNG nozzle is instantly heated to realize the deicing function and ensure the normal operation of the CNG nozzle in the later stage; in addition, the present invention does not need to add any hardware.

Description

A method and system for solving the difficulty of opening CNG nozzles in low temperature environment

technical field

The invention belongs to the field of engine electric control, and relates to a method and a system for solving the difficulty in opening a CNG nozzle in a low-temperature environment.

Background technique

CNG (Compressed Natural Gas, CNG) nozzle is the core component of the CNG engine, and its performance directly affects the function of the engine. The nozzles of CNG gas systems currently on the market are prone to freezing in low-temperature environments, which makes it difficult to open the nozzles and seriously affects the low-temperature start-up performance of CNG engines. When users encounter this kind of problem, they often heat the CNG nozzle with hot water before starting the engine until the ice on the nozzle melts. This has caused obstacles to the widespread use of CNG vehicles in cold regions, and has also limited the promotion of CNG vehicles in cold regions.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for solving the difficulty in opening the CNG nozzle in a low temperature environment;

The invention also provides a system for solving the difficulty in opening the CNG nozzle in a low-temperature environment.

In order to solve the above technical problems, the present invention adopts the following technical solutions.

A method for solving the difficulty in opening a CNG nozzle in a low-temperature environment is used in a compressed natural gas engine, and the method includes the following steps:

Step 1, the controller in the compressed natural gas engine judges whether the ambient temperature reaches the set low temperature condition according to the intake air temperature and the cooling water temperature of the compressed natural gas engine; if it reaches the set low temperature condition, then execute step 2, otherwise continue to judge the environment temperature;

Step 2, the controller instantaneously drives the CNG nozzle at high frequency, and the driving time corresponds to the ambient temperature.

As a preferred solution of the present invention, the set low temperature condition is equal to or lower than -5°C.

As another preferred solution of the present invention, the driving time is less than or equal to 1s.

As yet another preferred solution of the present invention, when the ambient temperature is -5˜-30° C., the driving time is 0.2˜1 s.

As another preferred solution of the present invention, when the ambient temperature is -10-25°C, the driving time is 0.36-0.84s.

As another preferred solution of the present invention, when the ambient temperature is -15-20°C, the driving time is 0.52-0.68s.

As another preferred solution of the present invention, when the ambient temperature is -18°C, the driving time is 0.6s.

A system for solving the difficulty of opening CNG nozzles in low temperature environments, used in compressed natural gas engines, the system includes a controller, the controller is used to judge the ambient temperature according to the intake air temperature and cooling water temperature of the compressed natural gas engine, when When the ambient temperature reaches the set low temperature condition, the CNG nozzle is driven at high frequency instantaneously to realize deicing.

As a preferred solution of the present invention, the set low temperature condition is equal to or lower than -5°C.

As another preferred solution of the present invention, the driving time is less than or equal to 1s.

The beneficial effects of the present invention are that: the present invention adds a low-temperature discrimination method to the CNG engine control system software, and ensures that the controller can instantaneously drive the CNG nozzle at a high frequency to heat the CNG nozzle instantaneously and realize the deicing function under low temperature conditions. Ensure that the CNG nozzle works normally in the later stage;

Another beneficial effect of the present invention is that: the present invention does not need to add any hardware, and ensures that the existing CNG system solves the problem of difficulty in opening the nozzles in a low-temperature environment without increasing costs and replacing nozzles.

Description of drawings

Fig. 1 is a schematic structural diagram of a CNG engine intake system;

Fig. 2 is a schematic structural diagram of a system for solving the difficulty of opening a CNG nozzle in a low-temperature environment according to the present invention;

Fig. 3 is a flow chart of the method for solving the difficulty in opening the CNG nozzle in a low temperature environment according to the present invention.

Detailed ways

On the premise of not adding any hardware, the invention realizes the normal opening of the CNG nozzle in the low temperature environment by changing the software of the CNG gas control system, saves the system cost, and greatly improves the starting performance of the CNG engine. The specific implementation manners of the present invention will be described in further detail below in conjunction with the accompanying drawings.

Embodiment one

This embodiment provides a method for solving the difficulty in opening the CNG nozzle in a low-temperature environment. The method is to add a CNG nozzle low-temperature drive function program to the original CNG engine control system, and the controller can judge the The ambient temperature of the current CNG engine, in the case of low temperature, the controller can drive the CNG nozzle with high frequency for a short time, so that the temperature rises rapidly, melts the ice, and improves the low-temperature starting performance of the CNG engine.

The flow of this method is shown in Figure 3, and the implementation steps are as follows:

Step 1, the controller in the compressed natural gas engine judges whether the ambient temperature reaches the set low temperature condition according to the intake air temperature and the cooling water temperature of the compressed natural gas engine; if it reaches the set low temperature condition, then execute step 2, otherwise continue to judge the environment temperature;

Step 2, the controller instantaneously drives the CNG nozzle at high frequency, and the driving time corresponds to the ambient temperature.

As shown in Figures 1 and 2, the CNG engine controller judges the current ambient temperature of the CNG vehicle through the cooling water temperature and intake air temperature signals. The CNG nozzle is driven by a high-frequency driving method. Although this driving method can instantly heat the nozzle and melt the ice on the nozzle, in order to protect the CNG nozzle from damage, the high-frequency driving method cannot last too long. In this embodiment, when the ambient temperature is equal to or lower than -5°C, it is called low temperature. The high-frequency driving time cannot exceed 1s.

Normally, the corresponding relationship between high-frequency driving time and ambient temperature is as follows:

When the ambient temperature is -5～-30℃, the driving time is 0.2～1s.

When the ambient temperature is -10～-25℃, the driving time is 0.36～0.84s.

When the ambient temperature is -15～-20℃, the driving time is 0.52～0.68s.

When the ambient temperature is -18°C, the driving time is 0.6s.

The invention adds a low temperature discrimination method to the CNG engine control system software, and ensures that under low temperature conditions, the controller can drive the CNG nozzle at a high frequency instantaneously to heat it up instantly, realize the deicing function, and ensure the normal operation of the CNG nozzle in the later stage. The invention does not need to add any hardware, ensures that the existing CNG system does not increase the cost and does not replace the nozzle, and solves the problem that the nozzle is difficult to open in a low temperature environment.

Embodiment two

This embodiment provides a system that solves the difficulty of opening CNG nozzles in low temperature environments, and is used in compressed natural gas engines. The system includes a controller, and the controller is used to judge according to the intake air temperature and cooling water temperature of the compressed natural gas engine. Ambient temperature, when the ambient temperature reaches the set low temperature condition, the CNG nozzle is driven at high frequency instantaneously to realize deicing. The set low temperature condition is equal to or lower than -5°C. The driving time is less than or equal to 1s.

The description and application of the invention herein is illustrative and is not intended to limit the scope of the invention to the above-described embodiments. Variations and changes to the embodiments disclosed herein are possible, and substitutions and equivalents for various components of the embodiments are known to those of ordinary skill in the art. It should be clear to those skilled in the art that the present invention can be realized in other forms, structures, arrangements, proportions, and with other elements, materials and components without departing from the spirit or essential characteristics of the present invention.

Claims (5)

1. solve the method that CNG nozzle opens difficulty at low ambient temperatures, in CNG engine, it is characterized in that, said method comprising the steps of:

Step one, according to the intake temperature of CNG engine and coolant water temperature, the controller in described CNG engine judges whether ambient temperature reaches the cryogenic conditions of setting; If reach the cryogenic conditions of setting, perform step 2, otherwise continue to judge ambient temperature; The described cryogenic conditions set is as being equal to or less than-5 DEG C;

Step 2, described controller moment high-frequency drive CNG nozzle, make the transient heating of CNG nozzle, driving time is corresponding with described ambient temperature; Described driving time is less than or equal to 1s;

Namely on original CNG engine control system, increase CNG nozzle low temperature drive function program, the ambient temperature that controller can be judged residing for current C NG motor by coolant water temperature and intake temperature, at low temperatures, controller can short time high-frequency drive CNG nozzle, CNG nozzle temperature is raised fast, melts and freeze.

2. solution CNG nozzle according to claim 1 opens the method for difficulty at low ambient temperatures, and it is characterized in that: when ambient temperature is-5 ~-30 DEG C, driving time is 0.2 ~ 1s.

3. solution CNG nozzle according to claim 1 opens the method for difficulty at low ambient temperatures, and it is characterized in that: when ambient temperature is-10 ~-25 DEG C, driving time is 0.36 ~ 0.84s.

4. solution CNG nozzle according to claim 1 opens the method for difficulty at low ambient temperatures, and it is characterized in that: when ambient temperature is-15 ~-20 DEG C, driving time is 0.52 ~ 0.68s.

5. solution CNG nozzle according to claim 1 opens the method for difficulty at low ambient temperatures, it is characterized in that: when ambient temperature is for-18 DEG C, driving time is 0.6s.