Solar powered vapor absorption system using propane and alkylated benzene AB300 oil

This paper describes experimental work on a solar assisted vapour absorption air conditioning system using Propane (refrigerant) and Alkylated Benzene (AB300-refrigeration lubrication oil, absorbent). Preliminary experiments to assess the miscibility of propane in various lubricating oils namely Shell Clavus oils 32 and 64 and Alkylated Benzene oils AB150 and AB300 indicated that Propane is most miscible in Alkylated Benzene AB300. The vapour absorption system is a single stage absorption consisting of evaporator, absorber, generator and condenser. The system is equipped with heat pipes installed between the absorber and the pre-generator to recover the heat of absorption. The heat applied to the generator replicated the solar thermal energy based on the climatic conditions of Jamaica using flat plate collectors commonly used in Jamaica. Experiments at various evaporator, absorber and generator temperatures showed that the coefficient of performance of the system increases with increasing the generator temperature and with decreasing the absorber temperatures. The solar fraction for the flat plate collectors to produce the generator temperature needed to drive the absorption system is up to 50%

Electrohydrodynamic boiling heat transfer enhancement at the evaporator of refrigeration plants

SIGLEAvailable from British Library Document Supply Centre- DSC:DX181972 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Optical Performance of Low Concentration Ratio Reflective and Refractive Concentrators for Photovoltaic Applications

AbstractSolar concentrators have the potential to replace the expensive PV cells with cheaper optical elements without affecting the overall output of the solar panel. Small scale concentrators with low concentration ratios offer the advantage of light weight, small size and easy to install without the need of tracking. Such concentrators use either reflective or refractive optical devices to focus the solar light onto a photovoltaic surface and increase its power output. Using advanced ray tracing techniques, this work investigates the optical performance of low concentration ratio reflective and refractive concentrators. Three different geometries of reflective concentrators and two geometries of refractive concentrators were investigated under the same range of concentration ratios. Results showed that both types of concentrators have similar optical efficiency for concentration ratios up to 10. For concentration ratios above 10, the performance of reflective concentrators has deteriorated significantly while the refractive concentrators have retained their high optical efficiency highlighting the potential of refractive concentrators

Thermal Analysis of Stirling Engine to Power Automotive Alternator Using Heat from Exhaust Gases

AbstractThis paper investigates the development of small scale beta type Stirling engine to recover the exhaust heat from the main engine and to drive the alternator (decouple it from the main engine), thus providing the required electrical power for onboard devices. The ideal adiabatic model was used to predict the thermodynamic performance of the engine. CFD investigation was also carried out to optimise the heater and the cooler geometry of the Stirling engine. The results showed that it is possible to generate a power output of 1.5-2kWe at an ideal thermal efficiency of 40% and engine overall weight of 11-14kg

Thermoelectric Cooling Device Integrated with PCM Heat Storage for MS Patients

AbstractMost Multiple Sclerosis (MS) patients are sensitive to temperature resulting in wide range of symptoms including fatigue and intention tremor. Published work showed that cooling the upper limbs can reduce the severity of these symptoms thus improving the quality of lives of MS patients. Currently available cooling devices are large, heavy and power intensive. This work aims to develop a compact light weight wearable upper limb cooling device that can be used to reduce the skin temperature to 10oC and for duration of 20 minutes. This work combines the heat pumping ability of thermoelectric devices together with the heat storage capability of PCM materials. Experimental work was carried out to investigate the performance of three different PCM materials. Results showed that PCM-OM37 with power input of 3W can deliver the required temperature of 10oC for duration of 20 minutes highlighting the potential of this proposed technology