Potential improvements of the Coefficient of Performance (COP) were investigated for R-407C at cooling and heating conditions of a residential heat pump. The study used CYCLE-11, a semi-theoretical vapor-compression cycle model, which was upgraded to simulate cross-flow, counter-flow, and parallel-flow evaporator and condenser with no restrictions on specifying superheated vapor and subcooled l...

A possibility of increasing interest for reducing the energy consumption in office and health care buildings consist in better exploiting the potential of the heat pump technology. This can be done by recovering heat at the condenser when the chiller is used to produce cold (simultaneous heating and cooling demands) or by using the chiller in heat pump mode (non-simultaneous heating and cooling...

A semi-empirical model for simulating thermal and energy performance of an automotive air-conditioning (AAC) system in passenger vehicles has been developed. The model consists of two sections, namely empirical evaporator correlations and dynamic load simulation. The correlations used consider sensible and latent heat transfer performance of the evaporator coil. The correlations were obtained f...

An Exergy method for theoretical analysis of a traditional vapour-compression refrigeration system equipped with liquid vapour heat exchanger (lvhe) for HFO-1234yf (2, 3, 3, 3-Tetrafluoropropene) and HFO-1234ze (trans-1, 3, 3, 3-tetrafluoroprop-1-ene), both ultra low Global Warming Potential(GWP) and zero Ozone Depletion Potential(ODP) refrigerants and comparison of the results with HFC-134a re...

Paiton 1-2 subcritical coal-fired power plant applied coal switching program in order to can compete at Jawa-Bali electrical system. The calorific value of consumed is switched from 5200 kcal/kg 4500 kcal/kg. As the result, it increases net heat rate (NPHR) as well flow and produce more CO2 emissions. Increasing final feed water temperature reduce NPHR because less needed steam. One promising m...

The performance of various working fluids for automotive air conditioning was calculated using a computer simulation. The model solves for the steady-state performance of a system that consists of a compressor, condenser, expansion valve, and evaporator, either with or without a liquid line/suction l i e interchanger. Condenser and evaporator performance is calculated based of user-defined valu...

There is a demand for reduced power consumption in the vapor compression refrigeration cycle. Coefficient of performance of window-air conditioners considerably decreases and power consumption increases under very hot conditions. These problems have encouragecl studies aimed at improving the performance of window-air-conditioners by enhancing the heat transfer rate in the condenser. In this ar...

This paper proposes an approach for improving the plant efficiency by reducing the heat rejection temperature of power cycle using Kalina Cycle System 11 (KCS11) which is integrated at the steam condenser of a 500 MWe SubC (subcritical) coal-fired power plant. It is modelled by using power plant simulation software ‘Cycle Tempo’ at different plant operating conditions. Results show t...