Experimental investigation was done to find the role of capillary tube length and amount of refrigerant charge on the overall heat transfer coefficient in condenser and evaporator and actual COP of a simple vapour compression refrigeration system. It was concluded that increasing of the refrigerant charge in the system largely enhances the overall heat transfer coefficient in the evaporator by ...

In order to dissipate the heat generated by electronic boxes in avionic systems, a copperwater LHP with a flat-oval evaporator was fabricated and tested at steady-state. The LHP consists of a flat shaped evaporator, 7 mm thick, including compensation chamber with attached heat exchanger. The condenser is cooled by forced convection of liquid. The variable parameters are the heat sink and ambien...

Capacity and efficiency of any refrigerating system diminish rapidly as the difference between the evaporating and condensing temperature is increased by reduction in the evaporator temperature. The single stage vapour compression refrigeration system is limited to an evaporator temperature of -40 C. Below temperature of -40 C the either cascade refrigeration system or multi stage vapour compre...

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...

In space during functioning, a satellite will be heated up due to the behavior of its components such as power electronics. In order to prevent problems in the satellite, this heat has to be released in space thanks to the cooling system. This system consists of a loop heat pipe (LHP), in which a fluid streams through an evaporator and a condenser. In the evaporator, the fluid captures the heat...

The subcritical Organic Rankine Cycle (ORC) with 28 working fluids for waste heat recovery is discussed in this paper. The effects of the temperature of the waste heat, the critical temperature of working fluids and the pinch temperature difference in the evaporator on the optimal evaporation temperature (OET) of the ORC have been investigated. The second law efficiency of the system is regarde...

This paper shows how formal characterizations of causality and of the method of comparative statics, long used in economics, thermodynamics and other domains, can be applied to clarify and make rigorous the qualitative causal calculus recently proposed by de Kleer and Brown (1984). The formalization shows exactly what assumptions are required to carry out causal analysis of a system of interdep...

The world is looking towards producing products which consume less power without compromising on quality of life. The increase in use of refrigeration and air conditioning appliances are contributing to global warming. The world wide temperatures are shooting up at an increasing rate. This paper presents a design of roll bond evaporator as the heat exchanger to provide cooling in room air condi...

This paper presents a comparable evaluation of R600a (isobutane), R290 (propane), R134a, R22, R410A, and R32 in an optimized finned-tube evaporator, and analyzes the impact of evaporator effects on the system coefficient of performance (COP). The study relied on a detailed evaporator model derived from NIST’s EVAP-COND simulation package and used the ISHED1 scheme employing a non-Darwinian lear...