Advanced Materials Research Vols. 860-863

Abstract: Allowing users to track the household metering energy consumed by their central air conditioning system is an extremely effective strategy for saving energy in commercial buildings. This paper presents several methods of measuring the energy consumed by a central air conditioning system, such as using time-based and energy-based models. The accuracy and reliability of these models are also compared with each other. Finally, a novel energy metering method, the improved electricity-based model, for a variable refrigerant volume (VRV) air conditioning system in commercial buildings is proposed based on a case study of the Li Wenzheng building at Southeast University. Keywords: energy; measurement method; VRV air conditioning; existing commercial buildings

Abstract: Compared with the water source heat pump system and the water air-conditioning system, and analyzed climatic characteristics and the status of water resources utilization in Zhejiang Province. The shallow surface water used for feasibility of summer air-conditioning cooling is analysis. As an example, testing water of a village in Zhejiang province Lin'an city, the shallow surface water can be directly used for the feasibility of the summer air conditioning cooling from the angle of water temperature, water quality, and the investment cost and operation cost.

Abstract: The paper presents a numerical simulation study of indoor thermal environment of an air conditioning office in winter in Hengyang. Considering the effect of air infiltration from window gap, the distribution of indoor temperature field, velocity field and humidity field can be obtained when air supply angle is 45° down to the horizontal direction. Compared with simulation which air infiltration is ignored, the results show that average temperature of air conditioning area reduces 0.6 °C in Y = 1.1 m section. Air velocity is larger in Y = 1.1 m air conditioning zone. The air speed is greater than 0.2 m/s in local area, a sense blowing. Average relative humidity is larger in Y = 1.1 m air conditioning area. The research indicates that air infiltration can not be allowed to be neglected in numerical simulation.

Abstract: It is necessary to monitor and optimize work status of central air-conditioning system (CACS) due to its high energy consumption. According to national standard, this paper designed a practical energy-efficiency evaluation method with double-layers structure. The upper-layer indicator reflects the whole energy efficiency of CACS. The lower-layer indicators reflect the energy efficiency of each subsystem of CACS, such as refrigeration system, chilled water system and terminal system. Using this double-layers evaluation system, the managers of CACS can not only observe the whole energy efficiency level but also find out the weak point of the system.

Abstract: A new model of the refrigerator with refrigeration and constant temperature and hot water has been trial-produced. The new refrigerator can not only keep refrigerated food quality, but also be used for heating or keeping food temperature constant, and supply hot water for us. The subsystems of condenser have been analyzed and designed including air-cooled method and water-cooled method. According to the theoretical calculation, the temperature in constant temperature box can keep about 50°C and 18.46 Kg hot water can be provided per hour.

Abstract: High-pressure air compressed by air compressor, is isobarically cooled and adiabatically expanded and is turned to low temperature air, which enters the adsorbent fluidized bed to freeze the materials. After the freezing of the materials, adsorbent will adsorb water vapor, which can play the effect of atmospheric freeze drying. The recovery power of the expander can be used as input power of the subsidiary refrigeration cycle. In order to adjust the temperature of the fluidized bed, evaporator coils of the affiliated refrigeration system are directly wound on the outer wall of the fluidized bed. This paper studies the combined refrigeration system, and analyzes the influence of different refrigerant pressure ratio, fluidized bed outlet air temperature, and refrigerant selection of subsidiary refrigeration cycle on the performance of the system.

Abstract: A three dimensional physical model for coupling calculation of flow and thermal transmission in induction machine is established in order to research the effect of stator ventilation on the performance of radiating with the method of finite volume element. The thermal fields of different ventilation structures under same basic size and equal total ventilation quantity of the induction machine are calculated and compared numerically. The results indicate that the addition of wind path will reduce the highest temperature in stator and cool the overhang portion remarkably.

Abstract: To study the effect of the biodiesel on the performance of the high pressure common rail diesel engine performance, a experiment is conducted about the high pressure common rail diesel engine uses diesel fuel and different blending ratio of biodiesels. The results show that with the rising of the altitude, the engine power and the brake specific fuel consumption reduce, exhaust gas temperature increases; At the same altitude, the engine fueled with different blending ratio of bio-diesel has higher brake specific fuel consumption in comparison with fueled engine, but it has lower power, with the increase in bio-diesel blending ratio, engine power, fuel consumption increase.

Abstract: Because the complexity and The diversity of the fault of large-scale power generation equipment system, it is difficult to carry out the analysis and evaluation for risk of equipment failure definitely and accurately. In the present analysis, most of them are complex function formulas, and not only is it difficult to understand, but also in poor operating in practice. At the same time, it is fail to be divided according to different faults of different devices In the issue of risk classification in the present study, so that the risk classification is not reasonable. This article is based on the research about equipment failure risk assessment, and by risk factors analysis to classify the risk of different failure for different devices. Maintenance mode selection is no longer based on the device but a combination of criticality analysis, and we can propose appropriate maintenance mode in the light of different fault of different equipment.

Abstract: The aim of this work is a case study of the adaptation bilateral switched reluctance linear generator to the exploitation of energy of the sea. This type of generator can be used to convert wave energy in electrical energy. In this paper we present an analytical sizing and FEM simulation. As for the results, analysis of the data extracted through the simulations it was possible to calculate the emf. The emf was calculated in two cases of motion of the slider: first hypothesis has set the constant speed while the second is a variable speed according to the law of an oscillatory motion of the sea.