Analysis on Energy-Flow of a Bipropellant-Powered Hydraulic Free Piston Engine

2011 ◽  
Vol 121-126 ◽  
pp. 3102-3106
Author(s):  
Bi Zhong Xia ◽  
Gang Su ◽  
Hai Bo Xie ◽  
Hua Yong Yang

Bipropellant-powered hydraulic free piston engine (BHFPE), as a new type of HFPE, takes advantage of bipropellant in place of conventional fossil fuel, and adopts a catalytic ignition instead of the conventional spark or compression ignition. In this paper, the operational principle and working process of a BHFPE are described firstly, then the chemical formula and molar mass as well as the heating value of the bipropellant i.e. kerosene/HTP combination are dealt with respectively. Thereafter analysis on the internal energy-flow i.e. energy input, transfer, dissipation and output, during a working cycle of the BHFPE are analyzed. Additionally the operating parameters such as working efficiency, maximum speed of the free piston assembly (FPA) and the output hydraulic energy are derived.

2014 ◽  
Vol 709 ◽  
pp. 28-31
Author(s):  
Hong Xin Zhang ◽  
Yu Qin Jiao ◽  
Tie Zhu Zhang ◽  
Lian Jun Cheng

Hydraulic engines can be widely used in many fields, such as agricultural machinery, construction machinery, duty vehicle, and many other fixing or mobile devices. The development analysis and study on their structural principle, technical and operational characteristics will be undoubtedly very useful for putting forward new type hydraulic engines. The structural principle of Hydraulic Free Piston Engine, Hydraulic Confined Piston Engine was introduced. The structural principle of Half Crank Hydraulic Engine (HCHE), which inherits the merits of traditional engine, HFPE and HCPE, was put forward.


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3530
Author(s):  
Fukang Ma ◽  
Shuanlu Zhang ◽  
Zhenfeng Zhao ◽  
Yifang Wang

The hydraulic free-piston engine (HFPE) is a kind of hybrid-powered machine which combines the reciprocating piston-type internal combustion engine and the plunger pump as a whole. In recent years, the HFPE has been investigated by a number of research groups worldwide due to its potential advantages of high efficiency, energy savings, reduced emissions and multi-fuel operation. Therefore, our study aimed to assess the operating characteristics, core questions and research progress of HFPEs via a systematic review and meta-analysis. We included operational control, starting characteristics, misfire characteristics, in-cylinder working processes and operating stability. We conducted the literature search using electronic databases. The research on HFPEs has mainly concentrated on four kinds of free-piston engine, according to piston arrangement form: single piston, dual pistons, opposed pistons and four-cylinder complex configuration. HFPE research in China is mainly conducted in Zhejiang University, Tianjin University, Jilin University and the Beijing Institute of Technology. In addition, in China, research has mainly focused on the in-cylinder combustion process while a piston is free by considering in-cylinder combustion machinery and piston dynamics. Regarding future research, it is very important that we solve the instabilities brought about by chance fluctuations in the combustion process, which will involve the hydraulic system’s efficiency, the cyclical variation, the method of predicting instability and the recovery after instability.


1947 ◽  
Vol 156 (1) ◽  
pp. 253-271 ◽  
Author(s):  
H. O. Farmer

The Pescara free-piston engine has been developed in France during the last twenty years, and the paper gives a description of a portable air compressor which has been proved in commercial work, and is now in production. An explanation is given of those characteristics in which this engine differs from the orthodox engine-driven crankshaft compressor. The power unit is an opposed-piston two-stroke compression-ignition engine, the compressor piston being directly attached to one of the engine pistons, while the cushion piston is directly attached to the other. The cushion piston gives stability, ensures that the energy available for the return stroke is constant for any conditions of operation, and thus gives a constant compression pressure in the combustion cylinder. The velocity characteristics of the pistons during the inward and outward strokes are described with their effect on the compressor and other sections. The fuel injection gear and also an alternative scheme is described; and indicator diagrams show the results obtained. The output of the compressor is controlled by the governor; the governor controls the fuel injected and thus determines the stroke of the pistons and thereby the quantity of air delivered. The efficiency of the combustion section is given, with the specific fuel consumption loop of the compressor as a whole. Methods of starting, by use of a spring or compressed air, are given to illustrate the characteristics dealt with. The development of the free-piston compressor has led to the development of the power gas-generator, in which the combination of free-piston compressor and turbine forms a new type of prime mover.


2018 ◽  
Author(s):  
Evelyn Evelyn ◽  
A. Rashid A. Aziz ◽  
Firmansyah Firmansyah ◽  
Ezrann Zharif Zainal Abidin

Sign in / Sign up

Export Citation Format

Share Document