Wei Shi

Research of Biogas as Fuel for Internal Combustion Engine

The component, physical & chemical characteristics of biogas and the problems of engines running on it are introduced briefly in this paper. The two main steps that are diesel injection ignition and fast-burning system, which are used to solve the problems of the low burning velocity, serious back burning, high exhaust temperature and severe heat charge for biogas engines are expatiated. Then the authors develop two kinds of biogas engines: biogas-diesel dual fuel engine generators and spark-ignition biogas engine generators. The authors also put forward to use biogas as the fuel for vehicle by purified and compressed.

Design and Implementation of an Electronic Control System for Oil-Free Scroll Air Compressor

Based on the introduction of the working principle of oil-free scroll air compressor, the hardware and software design of the electronic control system was given with a core of enhanced 51 SCM. Introduced the temperature sensor net made up of DS18B20, the realization of the AC signal acquisition method using a current transformer, and the man-machine interface consists of the digital tube array assembled by the 74LS595 and the independent type keys. The program of the electronic control system employs the work style of cyclical scan, which was developed by the C language in the Keil platform. The test results showed that the installed electronic control system can be operated reliably and trouble-free work continuously.

The Design of HCNG Engine Fuel System with Making Hydrogen by Sliding Electric Arc

This paper will put forward a device installed into the fuel system, which can use the sliding electric arc to electrolyze the natural gas to make hydrogen and then blend them in the fuel pipe for final combustion. This device can help to make a new type of HCNG engine fuel system, which electrolyses the single fuel (natural gas) partly to make appropriate-rate hydrogen for combustion. And in this paper, this new fuel system will be described in detail. The picture of sliding electric arc is shown in the end of this paper.

Study on Stability of Vehicle Mass Analysis System

A transient emission measurement system with VMAS is set up. The advantages, components and theory of VMAS are introduced. Twenty tests were made when the experimental vehicle was running in the best emission condition. In this paper, the system’s stability is discussed based on test results. The VMAS’ stability is great, and the data detected with VMAS can reflect the real situation of vehicle emissions. Then the importances are discussed about adoption the VMAS testing method for emission inspection of in-use petrol vehicles in China.

Study on LPG-Electric Hybrid Bicycle

A LPG (Liquefied Petroleum Gas) - electric hybrid bicycle is designed in this paper. In accordance with the different traffic conditions, the hybrid system, which contains a hub motor and a LPG engine, can work at engine-mode, battery-mode, and hybrid-mode, separately or in cooperation. The switching of these modes is electrically controlled. Thus the internal combustion engine can work in high efficiency and the bicycle has better dynamic and economic performance. It is worth to mention that, when LPG is used as the fuel, the system’s emission performance will be reduced considerably. At the same time, the noise performance will be further improved too. The storage battery works only at the stage of start and at the low-speed condition. Once the speed of bicycle is up, the LPG engine starts automatically and charges up the battery, which will prolong both the service life of the battery and the maximal travel mileage. As a result, the requirements of the battery’s capacity and weight can be significantly reduced.

Research and Development on Small Pipeline Natural Gas Generator

A 5 kW gasoline generator was converted into gas generator that could run on pipeline natural gas. A fire-restrain device and pressure reducer are designed to ensure safety. The measures such as increasing the compression ratio, enlarging spark advance and using a high-energy ignition are taken to improve the performance of the engine running on gas. Experiment has been done to compare the performances of the generator running on gasoline or natural gas. The result shows that the emission and economy of the generator are better when it runs on natural gas than that on gasoline.