Applied Mechanics and Materials Vols. 291-294

Abstract: It is the new way of the thermal power plant energy conservation to recycling plant circulating water waste heat for heating with the heat pump technology. The recovery of low temperature waste heat is the background. And lithium bromide absorption heat pump is the object of this study. The impact of changes in temperature parameters on the performance of heat pump unit is analyzed. As a theoretical basis for the design of the heat pump system and power plant heat pump unit’s optimal operation provide a reference. The result provides a theoretical reference for the optimal operation of the heat pump system design and power plant heat pump units.

Abstract: The characteristics of flow,combustion,heat transfer and NOx emission were numerically investigated under the different load operation for a 3000 T/H ultra-supercritical boiler.The simulated results agree well with the measured values. The results show that there is significant influence when oxygen amount in flue gas is different. The results show that compared with the increase of oxygen,coal burnout rate increase,fly ash carbon content is reduced,combustion efficiency is raised,and NOx emissions is reduced greatly,the flue gas temperature is reduced greatly chamber exports,which helps reduce panel superheater hang the tendency of slag,wall maximum thermal load obvious move down to middle burner and the lower between the burner area,boiler oxygen best in between 3.0 and 3.5.The direction information can be provided for mastering the combustion characteristics of this type of boiler,adjusting and optimizing the operation by the research result.

Abstract: The characteristics of flow, combustion, heat transfer and NOx emission were numerically investigated under the different load operation for an 1000MW ultra-supercritical swirling opposed coal-fired utility boiler.The simulated results agree well with the measured values. The results show that compared with 100% load all 6 mills in service, 70% load 4 mills is running, pulverized coal burnout rate increase, fly ash carbon content is reduced and NOx emissions reduced greatly, the flue gas temperature is reduced greatly chamber exports, which helps reduce panel superheater hang the tendency of slag, wall maximum thermal load obvious move down to middle burner and the lower between the burner area. The direction information can be provided for mastering the combustion characteristics of this type of boiler, adjusting and optimizing the operation by the research result.

Abstract: A heating system combined with solar energy and lake water source heat pump was designed for 200m3 fermentation reactor．In it could be switched to solar energy power mode, solar power with lake water source heat pump mode and lake water source heat pump mode according to different conditions. Compared with coal fired boiler, initial investment is a little higher, but for annual operating cost , this heating system is only 50% of coal fired boiler’s. But in the next several years, the initial investment can be returned back. For energy saving and economic, it is a suitable heat source for the biogas engineering in suitable area.

Abstract: In this paper, a paraffin heat storage ball whose diameter is 100mm is the research object. Two mathematical models of paraffin melting process are established respectively when the natural convection of liquid phase of paraffin is considered and ignored. The melting process of paraffin heat storage ball which initial temperature is 290K is simulated by using the solidification/melting model of FLUENT. Through analyzing the temperature distribution of the ball and proportion of solid-liquid phase in the ball in the melting process at a certain time, studying the time history of the proportion of liquid phase in the ball and the time history of the average temperature of the paraffin, we can find that the natural convection of liquid phase of paraffin can not be ignored in the melting process of paraffin heat storage ball whose diameter is 100mm.

Abstract: A test rig was built in the department of energy, in laboratory of refrigerating engineering for test runs with a lot of fluid and equipment of various kind for commercial refrigeration. The facility has been continuously improved during the past years and allows to perform experiments aiming to assess the performance characteristics both of conventional and new equipment for commercial refrigeration. In the test rig can be tested a lot of cooling loop filled with a secondary fluid for simulation of their behavior in industrial and commercial plants (e.g.: during exploitation in supermarket and hypermarket for refrigeration of foodstuffs in cold store, display cases and cabinets, etc.). The paper reports main results of the experiments performed with the new fluid R422A versus the original refrigerating fluid R22.

Abstract: Mine water and mine return air is good for the renewable energy due to heat storage underground, and the recycling has been a new technology of the energy utilization in water source heat pump system. Utilizing the waster heat of coal mine is beneficial in reducing the coal consumption of winter heating boiler or even replacing it completely. Comprehensive analysis the research situation and the project example, this paper points out that the technical of mine water applied for water-source heat pump system is feasibility in the practical project and theory in view of advantages, like energy saving, environmental protection, high efficiency and short payback period, etc. Therefore, application of mine water for water-source heat pump system is a new advanced energy-saving technology.

Abstract: In this paper, the characteristics of two modes of high back pressure reconstruction techniques for 150 MW reheat turbine units were researched. One was reconstruction of double back pressure and double rotors and the other was one-off reconstruction of LP cylinder. The former redesigned for lower pressure(LP) rotors for running at high back pressure, and hydraulic coupling bolts adopted to achieve the switch of low pressure rotors that run at high and lower back pressures. The one-off reconstruction of LP cylinder has achieved the switch of static and dynamic blades between high and low pressure. The two reconstruction both realized heat supply on the high back pressure condition, utilized cold source loss and increased the unit efficiency. After reconstruction, the economic index under both normal back pressure condition and high back pressure heating condition have been obtained by performance test. Under the high back pressure heating condition, the unit heat rate reaches 3700-3800kJ/kW.h, and the thermal efficiency has achieved 95-97%.

Abstract: 116MW circulating fluidized bed hot water boiler performance testing was carried out that found that burning high volatile lignite had post combustion phenomenon of separator yet. The phenomenon of post-combustion research results show that flue gas outlet temperature rise of the separation can be significantly reduced by adjusting the twelve wind ratio; Increasing coal-fired granularity which was able to reduce the separator post combustion phenomenon; Moderate post combustion of separation was able to improve boiler efficiency and reduce N2O. These results can provide guidance for improving boiler operation technology and improving the boiler design standard.

Abstract: Combustion characteristics of a Helmholtz-type valveless self-excited pulse combustor with continuous supply of gas and air were studied. The physical and mathematical models are established based on the actual pulse combustor, and the combustion characteristics are simulated with CFD. The results show that the possible re-ignition sources for the pulse combustion may be three. The first source may be the hot remnant gas near gas/air mixture. The second re-ignition source may be the high-temperature combustion chamber wall. The third ignition source is the unburned mixture. The pressure, temperature and mass fraction of propane in the combustion chamber have the phase relations and the combustion process stimulates the acoustic oscillation.