In this work, the performance of an innovative evaporator based on water falling film was investigated. The studied has been equipped with a recirculation system to maximise wetted surface. Tests have carried out in lab-scale adsorption unit connected test bench recently realised at Politecnico di Milano labs for evaluating heat transfer performances under realistic operating conditions. Severa...

The ability of zeotropic mixtures with a temperature glide to operate in liquid recirculation systems is investigated in this paper, and the preliminary results of an experimental comparison between the performance of R134a and of zeotropic mixture R32/Rl34a, (25/75 by mass) are presented. The perfonnance of Rl34a operating in dry expansion mode are also presented as baseline data. INTRODUCTION...

This paper presents a novel approach for experimentally simulating various environmental conditions and container parameters on air conditioning and refrigeration (AC&R) systems. The proposed emulation technique uses a hardware-in-the-loop (HIL) system to simulate the loading conditions on the evaporator during experimental testing. The evaporator air inlet conditions are controlled with a smal...

This paper focuses on the computer cooling capacity using the thermosyphon loop with minichannels and minipump. The one-dimensional separate model of two-phase flow and heat transfer in a closed thermosyphon loop with minichannels and minipump has been used in calculations. The latest correlations for minichannels available in literature have been applied. This model is based on mass, momentum,...

A simulation model for the CO2 heat pump water heater was developed and validated in this study. Component models of the gas cooler, evaporator, compressor, and expansion valve were constructed with careful consideration for the heat transfer performances. To validate the simulation model, experiments were carried out using an actual CO2 heat pump water heater (water heating capacity: 22.3 kW; ...

Yam tuber (Dioscorea spp.) is a staple tropical crop that usually best eaten in its fresh form. However, inadequate preservation and storage can result yam tubers deterioration immediately after harvesting due to their relatively high moisture content. All the traditional structures of preserving storing could not maintain freshness for long time. Therefore, need developing new structure farm p...

This study aims experimentally to investigate the performance parameters of R134a and alternative R516A refrigerant in two evaporator ejector cooling system (DEES) at different air velocities evaporator#1. Firstly, tests were carried out with under steady-state conditions then repeated low GWP refrigerant. As R134a, higher capacity was achieved velocity values. When value 1.1, 1.7, 2.2, 2.7 m s...

A theoretical study is conducted to explore the effect of different parameters on the performance of a Loop Heat Pipe (LHP). These parameters are evaporator temperature, condenser temperature, total mass charge, the tube size of piping system, and pumping distance between evaporator and condenser. This paper pres ents a steady state model that describes the thermodynamics, heat transfer, and fl...

This paper deals with the investigation of substitutes for R-22 and their heat transfer behaviour in a plate-type evaporator with a falling water film as heat source. Alternatives investigated were R-134a and two new refrigerant mixtures. Measurements on a 3m x 0,5m plate showed a superior performance ofR-134a compared to R-22 and mixtures at equal test conditions and a distinct difference betw...

Given the rapid progress in the electronics industry, the thermal management of electronics components becomes an important and serious issue. Natural and forced cooling are often deficient. One possibility for heat dissipation for high heat flux is using loop heat pipe. A loop heat pipe (LHP) is a two-phase device with extremely high effective thermal conductivity that utilizes pressure differ...