Advanced Materials Research Vols. 608-609

Abstract: The alternator output power in the power system can be divided into active and reactive power. The active power (in kW) is that part of the electrical energy for doing work and heat loss, such as the conversion of mechanical energy, heat, light. The reactive power (in kVar) is that part of the electrical energy for the exchange of electric and magnetic fields in the circuit, such as transformers, motors, through the magnetic field can be passed to convert electrical energy; transmission lines in cable systems and a variety of load reactance (inductance and capacitance), and consumption of reactive power. With the rapid development of power system to study how to reduce energy loss in the power system is a very meaningful. In this paper, The Shizuishan plant desulfurization project as an example, illustrates the shunt capacitor reactive power compensation of the power system energy saving.

Abstract: According to the information of a large-scale public building in Shanghai, annual hourly loads of cooling, heating and power are calculated separately on the basis of Hourly Load Apportionment Ratio Method. Based on load characteristics and local practical condition, three cases are proposed for further comparison and selection by PRUE, ESR, CRR and PBP, and then the optimal case is to be determined. Moreover, the impact of installed capacity and gas price on the effect of applying CCHP system would be discussed. The result shows that both hotel and office area are appropriate for utilizing CCHP system; the combination of electro-refrigerator and absorption refrigerator is more economically preferable; PBP increases at first and then decreases while the capacity of electric generator rises, and when the capacity of generator and refrigerator are 4000kW and 4500RT, the PBP is lowest; The PBP will be 3 to 5 years if the price of natural gas could be fixed between 2.5 Yuan/m3 and 3Yuan/m3, which is a remarkable indicator of economical efficiency.

Abstract: To improve the performance of greenhouse monitoring system based on WSN, an algorithm was proposed. By grey prediction of WSN current feedback values, the sampling values of the following variables can be predicted. The paper discussed the relation of grey prediction model dimension and the predicting precision, and the control effect was analyzed. This method solved the discrete and lagging problem, it will effectively save the battery energy of WSN node and reduce the energy consumption in greenhouse by improving system stability.

Abstract: Have proposed a heat recovery of fresh air ventilator system form,which is based on the technology of refrigerant natural circulation named heat-pipe. Describes the working principle of the unit, designs a new type of heat recovery air ventilator test equipment,and carries out a experimental study on its running performance.Have come to the effect of air flow and the temperature difference between indoor and outdoor for the heat recovery rate. Experimental results show that this equipment has a high heat recovery efficiency and a good effect on energy-saving . Through experimenting on the performance, laying a foundation for further optimization of unit design.

Abstract: In order to heat the gas of Boiler tail to comply with request of emission temperature of environmental regulations, heat pipe gas to gas heater (GGH) is used in the wet flue gas desulfurization (FGD) system. Heat pipe GGH is characterized by high efficiency, small losses of fluid resistance, and no leak of the flue gas, and desulfurization system possesses higher desulfurization efficiency, no additional power consumption, low costs of operation and maintenance, and it also solves the problem of acid corrosion and scaling, which is more suitable for wet flue gas desulfurization system.

Abstract: Metal honeycomb is a kind of new plug-in unit for enhancing heat transfer, which is easy to adjust its specific surface area, excellent in heat conduction and flexible in geometrical transformation. The structures of honeycomb are optimized by FLUENT and orthogonal experiments. It is concluded that the heat exchange capability of honeycomb is most affected by the relative size representing screw pitch or screw diameter to metal wire diameter, less by the diameter of metal wire, and least by extensional rate under continuous heat recovery process. Moreover, it is found that the honeycomb has the best performance in heat transfer with metal wire diameter of 1.0 mm, relative size 8(corresponding to screw pitch and screw diameter 8.0mm) and extensional rate 0.7.

Abstract: By analyzing and comparing several types of enhancement of heat transfer measures used presently in condenser, a new method of augmentation condensation heat transfer is presented in this paper, that is, tube inserts with porous body of large porosity---twined coil. And the theoretical analysis and experimental investigation are carried out. The results show that it can make the fluids perform complicated three-dimensions mixed flow, make the heat flux appear “sudden” jump at lower temperature difference, make the flow go into turbulence ahead of time. The heat flux enhancement ratio increases by 3-4 times. If compared with other inserts, twined coil insert not only has better heat transfer enhancement performance, but also produces very small pressure drop, so it is an ideal and high efficiency energy saving technology. In the view of its application prospect, the feasibility of twined coil inserts applied to solar heat pump system is analyzed.

Abstract: Heater terminal temperature difference is one of important equipment of thermal system, the influence of terminal temperature difference on thermal economy is great. The accurate calculation of terminal temperature difference influence on thermal economy is helpful to thermal system design, operation and maintenance work. This article took a 300MW steam turbine as an example, adopted the equivalent heat drop method to calculate various levels heaters terminal temperature difference influence on the live steam work load, circulation heat and cycle thermal efficiency.

Abstract: As one of the effective ways of building energy saving, behavior energy-saving has the positive promotion function regarding the heating energy saving for the heat users of central heating system. The effect of behavior energy-saving on the heating load characteristics of central heating systems was studied based on the present development of central heating metering technology. The study was promoted combined the theoretical analysis and questionnaire survey. At first, the influence factors of behavior energy-saving were analyzed. Then the questionnaire survey about the present situation of behavior energy-saving was carried out and the basic heating modes of heat users were summarized considering on heating mode, habits and customs and the family structure characteristics. The concept and mainly form of behavior energy-saving and behavior energy-saving rate of central heating system heat users were clear and definitude by study on the behavior energy-saving rate. Thus it has good coaching and promoting effect on the development of behavior energy-saving.

Abstract: Invention and the widely use of air conditioning has improved people’s working and living conditions. However, it also consumes significant amount of energy, accounting for over 40% of total energy used in the buildings. Indirect evaporative cooling (IEC) is a relatively new kind of air conditioning mechanism developed. It is not only uses less energy comparing with traditional air conditioning, but also overcomes the weaknesses of a direct evaporative cooling (DEC) system. The weaknesses of DEC include humidifying the supply air and minimum temperature of supply air is not lower than wet bulb temperature.