in this paper the changes in the heat capacity of cooling towers has been investigated as a result of injecting combustion products of boilers. in the tower, the air is re-heated through mixing with hot flue gas after passing through the heat exchangers. as a result of this process, the draft of the cooling tower is increased. the additional produced draft depends on the ambient temperature and...

Besides permitting an accurate determination of the ferromagnetic-to-paramagnetic phase transition temperature and the characteristic temperatures for the beginning and end of the growth of martensite (austenite) phase at the expense of austenite (martensite) phase while cooling (heating), the results of an extensive ac susceptibility, sound velocity and internal friction investigation of the t...

In this study, thermal behavior of aqueous solutions of methyl cellulose (MC) at a constant temperature of 50 degrees C was analyzed. Various samples were studied for two consecutive heating-cooling cycles. The experiments with the solutions prepared using cold de-ionized (DI) water showed that the rate of gelation was higher for higher MC concentrations. However, the rate was slower during the...

The paper focuses on the operation of simple refrigeration cycles. With equipment given, there are, from a control and operational point of iew, five steady-state degrees of freedom; the compressor power, the heat transfer in the condenser, the heat transfer in the evaporator, the choke alve opening and the active charge in the cycle. Different designs for affecting the active charge, including...

Chandra X-ray Observatory has revealed X-ray cavities in many nearby cooling flow clusters. The cavities trace feedback from the central active galactic nulceus (AGN) on the intracluster medium (ICM), an important ingredient in stabilizing cooling flows and in the process of galaxy formation and evolution. But, the prevalence and duty cycle of such AGN outbursts is not well understood. To this ...

As global warming has raised more critical concerns in recent years, refrigerants with high global warming potentials (GWP) are facing the challenges of being phased out. R410A, with a GWP of 2,088, has been widely used in residential air-conditioning and heat pump systems. A potential substitute for R410A is R32, which has a GWP of 675. This paper investigates the performance difference of R41...

Combined cooling, heating, and power (CCHP) systems produce electricity, cooling, and heat due to their high efficiency and low emission. These systems have been widely applied in various building types, such as offices, hotels, hospitals and malls. In this paper, an economic and technical analysis to determine the size and operation of the required gas engine for specific electricity, cooling, ...

Cycles for heating and cooling have been studied in detail when it comes to thermodynamics and design. However, there are few publications on optimal operation with given equipment which is the theme of this paper. One important issue is which variable to control during operation, for example super-heating, pressure, liquid level or valve set-point. Unlike open systems the initial charge to the...

Cycles for heating and cooling have traditionally been studied in detail when it comes to thermodynamics and design. However, there are few publications on their optimal operation which is the theme of this paper. One important issue is which variable to control, for example, degree of super-heating, pressure, liquid level or valve opening. Also, unlike open systems, the initial charge to the c...