this paper describes a study that starts with an analysis of typical energy demand profiles in a hospital setting followed by a case study of a combined cooling, heating, and power (cchp) generation system.cchp is an autonomous system that combines the generation of electrical, heating, and cooling energy.the driving units are two high-efficiency gas engines that produce electrical and heat ene...

This paper presents the analysis results of R429A, R430A, R431A and R435A as drop in substitute for R152a at various evaporating temperature with condenser temperature 30°C, 40°C and 50°C. A theoretical study of thermodynamic properties such as pressure, density, and specific volume, latent heat of vaporization compression index, and critical values are done. The theoretical performance of vapo...

During extremely hot summer days, air conditioning systems are known as major electricity consumers in residential, commercial and industrial sectors. Moreover, high energy requirement of multiple-chiller plants may cause an interconnected power grid be faced with annual on-peak electrical demand, load-generation mismatch, voltage collapse and catastrophic wide area blackout. Therefore, this pa...

A refrigeration system which was originally designed using R502 as refrigerant was rebuilt to adapt the special requirements of R404A. The experiments, both for R502 and R404A, on this system were done and some parameters such as evaporating temperature, condensing temperature, discharge temperature, compressor input power and so on were measured under different working conditions. Then the ope...

The purpose of this paper is multi-objective optimization of refrigeration cycle by optimization of all components of the cycle contains heat exchangers, air condenser, evaporator and super-heater. Studied refrigeration cycle is compression refrigeration cycle of unit 132 Third refineries in south pars that provide chilled water for cooling refinery equipment's. Cycle will be performed by t...

Electricity generation in thermal power plants as the largest producer of electricity in Iran is associated with greenhouse gas emissions. In this paper, using the Malmquist-Luenberger method, green productivity, and efficiency changes are measured for 31 thermal power plants (including 12 steam power plants, 13 gas power plants, and six combined cycle power plants) during 2009-2016. The result...

the continuous spread of distributed energy resources (ders) such as combined heating and power (chp), diesel generators, boilers and renewable energy sources provide an effective solution to energy related problems to serve the power and heat demands with minimum cost. moreover, the ders may play a significant role for supplying power and heat in rural areas, where grid electricity is not avai...