The Structure Design And Performance Analysis Of Low-pressure Steam Generation Device

At present, the traditional and mature waste heat recycling technology does not apply in low grade waste heat recovery, and its power generation system mainly includes heat boiler and steam turbine, which cannot achieve economic and feasibility characteristic of low grade waste heat recovery. In order to overcome these technical difficulties, the roots-steam engine is put forward in this article, which is a new type equipment of low grade waste heat recovery. This article conducts the feasibility study of equipment in analysis of the low grade heat resource, working principle, numerical simulation and experimental analysis, etc.Firstly, to assess the energy saving potential of low grade waste heat, its heat energy value and exergy are obtained using the first and second thermodynamics. The results indicate that low-temperature flue gas and the sensible heat objects have great recovery potential.Secondly, the parametric design of the rotor which is a key part of roots-steam engine is conducted. Geometric method is used to deduce the rotor profile line equation. And the3 D model of rotor is established according to actual profile line equation. According to the structure and principles of the roots-steam engine, the torque and flow rate were derived by the theory of fluid mechanics and gas pressure transmission. The theory flow rate and the torque were calculated based on the relationship established. Furthermore, the static characteristics of roots-steam engine were analyzed about rotational speed, torque and flow rate.Thirdly, according to temperature, pressure and parameters of the fluid, the roots-steam engine was simulated in low grade waste heat working condition. The3 Dcomputational model of roots-steam engine was established by numerical simulation method. The internal flow field changing process of roots-type engine was simulated in low grade waste heat condition based on dynamic mesh technique, and distribution of pressure and velocity field was achieved at different times and locations. So the simulation results reflect the dynamic performance of roots-steam engine in low grade waste heat.Finally, test platform of the low grade waste heat generation system has establishedwith roots-steam engine at the core. The properties of the generation system were tested,including flow,pressure and power, etc. Experimental research shows that it is feasible that roots-steam engine recycles low grade waste heat to produce power, and the test result fits the theory analysis well.