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...

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...

There are two kinds of dual split type air-conditioner. One is of using two compressors for two indoor units; the other has only one compressor for two indoor units. The EER and refrigerating capacity of the former kind are just the same as the single split type's. But to one compressor dual split type system, there are two working ways: 1. compressor and both two indoor units operating, and 2....

The evaporator in a frost-free refrigerator typically has more tube rows, but frost deposition reduces along the airflow direction. Correspondingly, fin distribution is thinner upstream rows denser downstream, and good match between achieved to recover capacity loss. However, quantitative design principles of non-uniform are lacking. A quasi-static frosting model established experimentally veri...

The usual residential or small commercial air conditioning systems use air cooled condensing sections. The instantaneous condensing tempera~ ture is a function of ambient air temperature, condenser air quantity, and the mass flow and superheat of the refrigerant entering the condenser. System energy requirements are currently expressed in terns of Btu/watt~hour at "design" ambient for normal ap...

In this study, the energetic and exergetic performance merits of an automotive air condition-ing (AAC) system using R134a R1234yf have been investigated. For aim, a laboratory AAC was developed equipped with devices for mechanical measurements. The refrigeration circuit mainly had evaporator, condenser, liquid receiver, fixed capacity compressor, thermostatic expansion valve. tests were perform...

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...