the underground temperature at a depth of about three to four meters is almost constant during the year. as a result in summer the underground is cooler than the ambient temperature. this potential is considered for greenhouse cooling by using an earth-to-air heat exchanger (eahe). in this research the effects of two parameters were investigated: a) the area of greenhouse in three levels of 9, ...

A fuzzy logic controller of the heat recovery systems of cement clinker grate cooler is presented in this paper. The development and tests of the proposed fuzzy controller have been implemented in a cement plant in Guangdong, China. Cooling is performed by blowing fresh air underneath the grate cooler plate and heat recovery is obtained by outlet pipe extracting the hot air. However, continuous...

We have found that camels can reduce the water loss due to evaporation from the respiratory tract in two ways: (1) by decreasing the temperature of the exhaled air and (2) by removal of water vapour from this air, resulting in the exhalation of air at less than 100% relative humidity (r.h.). Camels were kept under desert conditions and deprived of drinking water. In the daytime the exhaled air ...

1. introductionhumans have actively managed and transformed the world’s landscapes for millennia. after the industrial revolution (between 1820 and 1840) with increase in sanitation, food security and quality of life the human population increased tremendously. urbanization, the demographic transition from rural to urban, is associated with shifts from an agriculture-based economy to mass indus...

The purpose of the study is to investigate average and local surface heat transfer coefficients in a cylinder packed with spheres. Here the term «local» applies to a single sphere within the bed. Averages are derived from the sixteen different spheres that were instrumented and distributed throughout the bed. The experimental technique consisted of introducing a step - wise change in the temper...

Selective emittance materials show high technical potential for use as radiative cooling heat exchangers for buildings. This paper presents the thermal modeling of the photonic radiative cooler and the simulation of a system that integrats the photonic radiative cooler with radiant floor cooling in a medium office building. The system was simulated with EnergyPlus and the extensive use of its e...

In the present work, the performances of improved two-stage multi inter-cooler trans- critical carbon dioxide (CO2) refrigeration cycles with ejector and internal heat exchanger have been examined. In the new improved cycles, an internal heat exchanger is append to the cycles. Also, second inter-cooler in improved cycles, cooled with the refrigeration of the cycle, so that in first c...

characteristics of efficient roof shape is a part of configuration of efficient architecture which seems to be an ideal in contemporary architecture especially in contemporary architecture of developing countries such as iran. this study is to investigate two roof shapes in view of air flow and indoor-temperature to find efficient roofs shapes for residential buildings in tehran. computational ...

Gas turbines play an important role in supplying power for the country especially in peak electricity load. The main disadvantages are the turbines, they produce large changes are a result of climate change. However, in times of peak electricity grid and at the same time warm months, can produce gas turbines under the effect of ambient temperature, the amount of reduced considerably. The method...