In this paper, the steady state thermal conditions of body exercising in a hot environment is evaluated, in which the thermal equilibrium of human body seems to be attained in less than one hour. An assumption, that the regulatory thermal sweating rate is a linear function of the deviation of mean skin temperature from that of thermal neutrality, is tested and proved to be acceptable.
CCAnalytically modeling the complex fluid flow phenomena that occurs during natural convective heat transfer in fenestration system cavities (windows, doors, skylights, curtain-walls, etc.) is a complex task. Laminar flow of a fluid in a tall vertical glazing cavity can occur in the form of single cell or as a stable multicellular flow. Until the early 1980s, experimental results were mostly available, along with limited analytical studies based on theoretical considerations.
Genetic algorithms are introduced as a tool for solving parametric optimisation problems, and their previous use in engineering applications is reviewed. The fundamental genetic operators for reproduction, crossover and mutation are described and current areas of research indicated. Results are presented for an experiment carried out to evaluate the performance of genetic algorithms in optimizing the design of a variable air volume air conditioning system. The mathematical model of the system is described, as is the method of evaluating system performance.
Agricultural products play a significant role and could yield substantial amount of foreign exchange for a tropical country like India. However, in India 30% of the agricultural products are spoiled in storage and transit.
Moisture is one of the most important factors affecting building envelope durability and performance, especially in cold climates. Understanding and predicting moisture movement within and through the envelope is therefore of fundamental importance. Although computer modelling of building envelope hygrothermal performance has made great strides in the last decade, one of the largest sources of moisture remains relatively poorly understood : driving rain.
The energy rehabilitation of district heating system requires a proper expert survey of secondary loop including thermal substation, heat carrier distribution network and buildings of residences. This paper present the theoretical fundamentals as well as the measurements specific to the procedure used in assessing the thermal characteristics of the heat exchangers, network and buildings of residences. The results obtained were used in the diagnosis activity supported by the SIMPATIC software.
The centralized cooling plant considered equips an important office building in Brussels. This 54 000 mP2P building has a design cooling demand of about 5.7 MW. To meet the cooling loads, the chilling plant can use five counterflow cooling towers, four twin-screw chillers and four tanks with encapsulated ice. The purpose of the commissioning is to check the thermal performance of the primary equipment and to use the simulation tools to give a correct forecast of the cooling capacity available as well as the cooling energy stored in the ice storage tanks.
Thermoeconomics is the combination of thermodynamics using exergy with economics. The objective of thermoeconomics is to minimise a total cost function, which includes capital, maintenance and running costs. This will establish the most cost effective, or optimal, design parameters. This paper shows the application of thermoeconomic analysis to a building services system, consisting of a constant air volume (CAV) air conditioning system. The specific cost of indoor environment cooling is optimised in terms of system variables, such as water and air temperatures and mass flow rates.
Air quality in the surroundings of three cement plants, which are the most representatives for different industrialization levels (one in Belgium, one in Algeria and one in Vietnam), is estimated by gaseous and dust concentration measurements and fall-out dust networks. Heavy metals, especially the ecotoxic elements are determined. The deposition rates are presented as a function of source-distance in order to emphasize the pollution dispersion varying with prevailing winds.
Most domestic refrigerators are supplied with an energy rating label which con-sumers can use to assess the quality of their appliance. This rating can be deter-mined by (a) testing the refrigerator under specified environmental conditions ac-cording to relevant standards and measuring its power consumption, or (b) analys-ing the refrigeration cycle thermodynamically, or (c) measuring the heat transfer through the walls of the refrigerator cabinet and its doors gaskets. While refrig-erator manufacturers use the first technique, most researchers take the second ap-proach.
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