Advanced Materials Research Vols. 860-863

Abstract: This paper formulates a radial basis function meshless method for the numerical simulation of the advection-diffusion problems. The spatial derivatives are approximated by RBF collocation technique whereas the temporal derivatives are discretized using the Crank-Nicholson method. Corresponding boundary conditions are enforced analytically at a discrete set of boundary nodes. The performances of the present method are demonstrated through their application to an advection-diffusion problem.

Abstract: The objective of this work is to model the cutting properties generated during grinding with internal lubricating wheel. Grinding FEM was carried out with this internal lubricating wheel. The machining properties were assessed in terms of grinding temperature. The results showed that an obvious effect in decreasing the cutting temperature can be obtained by reducing the friction coefficient between the self-lubricating wheel and the TC4 alloy through delivering the solid lubricant directly to the surface of the wheel without the use of inner coolant conditions.

Abstract: This paper used physical modeling method to simulate the running state of each component of the air conditioner, got the ideal conditions of air conditionor energy consumption model and then calibrated and corrected the model of the air conditioner energy consumption by the experimental data. After utilizing the model for the performance analysis of the actual air conditioner, it was found that the extreme outdoor climate would affect the performance of the air conditioner. In summer, the electricity required to produce the same amount of cooling capacity will be 210% compared with 30°C of outdoor temperature, when the outdoor temperature is 50 °C; In winter, the drop of outdoor temperature will seriously impact on the energy efficiency of air conditioner, when the outdoor temperature is-5°C the electricity required to produce the same amount of cooling capacity will be 150% compared with 10 °C of outdoor temperature. It is of great significance that the results shown in this research contributes to the analysis of air conditioner in extreme conditions, and amended energy consumption of the model can not only forecast the performance of household air conditioners under the extreme climate but also indicate the future direction of air conditionersdesign and improvement.

Abstract: The primary mission of this design is the air conditioning design of a hotel in Guangzhou city. The calculation of cooling load & heat load, division of the air conditioning system and the determination of the scheme, the design of the duct and water system, and the design of the smoke prevention and extraction system are all included. According to the related standard and considering the energy saving and comfort requirements, the air conditioning system are determined through the economic and technological comparison. Primary return air system is used for open office area and dining hall; fan-coil units with fresh air system is adopted for the guest rooms of the hotel; and the VRV system is adopted for the large conference room. The new air in restaurant rooms and the large conference room is handled by full-heat type fresh air exchanger; new air in guest room is handled by air conditioning units.

Abstract: This paper deals with the study of air-condition temperature control, which is a complex system of time varying, nonlinear, imprecise model and uncertain work environment. In this paper, a multiple models fuzzy PID controller is designed. Considering the air-condition temperature adjustment system to combat aircraft and the frequently changing external environment the multiple fuzzy PID controllers are estimated according to the temperature changing area. Each time, based on temperature tested, only one fuzzy PID Controller is chosen to improve the control precision. At the end, simulation results show that multiple model fuzzy PID control is superior to the single fuzzy PID control, which effectively improve the transient response of the system, the steady state accuracy and robustness, having good prospects for engineering applications.

Abstract: Aiming at three frequently used air conditioning systems of an actual building, the system boundary under simplified and hypothetical conditions was built according to different research objectives and scopes. And the life cycle assessment model frame was created and the carbon footprint of three plans was analyzed. To collect relative data of energy consumption and emission which were produced in the stages of units operating, the resources obtaining and manufacturing, then the obtained data were arranged into inventory analysis table. In accordance with the characterized model environmental exhaust was transformed to environmental load while normalization and weighted evaluation were also made, from which different environmental impacts potential values could be attained. So as to the environmental impact of life cycle of air conditioning systems could be quantitatively described by the environmental impact load. Ultimately the study conclusions were procured as follows: electric water chiller plus natural direct-fired lithium-bromide absorption chiller/heater makes the least environmental impact followed by the electric water chiller plus gas boiler and water source heat pump makes the most.

Abstract: This paper introduces a way to build a model for a new kind of solution dehumidifier, and discusses the way to construct TRNSYS components for different kinds of solution dehumidifiers, and the factors that have the most important influence on the precision of the component have been presented. This paper contribute to the component library of TRNSYS, which will make TRNSYS capable to simulate THIC system.

Abstract: The trans-critical CO₂ refrigeration cycle involving a regenerative process is analyzed in this paper. The thermodynamic performance of the cycles with regeneration and without regeneration has been compared. The optimal circumstance for the regenerative process set in the trans-critical CO₂ cycle is given. The impact of the regeneration on the performance of the system under difference operating conditions is also discussed in this article.

Abstract: Experiment was carried out to test heat and mass transfer performance of cross-flow dehumidifier using metal packing. The effects of air flow rate, solution flow rate and inlet parameters of air and solution on the outlet parameters were also investigated. And a great deal of data obtained from experiment was processed using multiple linear regression method. Empirical formulas were given such as the rates and efficiency of dehumidification evaluating performance of dehumidifier, which provided good reference and necessary information for further theoretical investigation.

Abstract: The new fluidization method of liquid-liquid circulating fluidized bed proposed for ice slurry production was investigated experimentally. Multiple small water-drops were formed in another immiscible liquid coolant by a single-nozzle atomizer and frozen in the fluidized bed by direct contact heat transfer. Experiments were conducted to research the dynamic behaviors of jet and drops formation in the ice making system by the high resolution digital camera and image processing. The photos of jet development, breakup and drop formation were obtained. The affects of the shape of jet breakup, jet length and its surface fluctuation on drops size were revealed. The range of drop sizes and the sloping extent have always increased with the jet rate increasing. And varying jet shape directly results in the jet breakup into droplets under different time and test conditions, so the variation laws of the jet shape contribute most to the quality of the liquid drop, such as drop size distribution.