Experimental analysis of a solar absorption system with interior energy storage

This study examines experimentally the cooling application of a solar absorption system with interior energy storage that uses two different auxiliary systems. The experiments were performed at Uludag University, Bursa, Turkey on the 3rd and 4th of August 2010 that had the approximately same average outdoor temperature, 31°C. A solar hot water was delivered via a 40 m2 array of flat plate solar collectors that drove a lithium chloride (LiCl) absorption heat pump with a cooling power peak of 20 kW. A solar-powered air conditioning system was designed for heating and cooling in a test room that had a total floor space of 30 m2. Chilled water produced in the evaporator was supplied to the fan coil units, and the heat of condensation and absorption was rejected by means of a wet cooling tower. An electric heater and an air source heat pump were used as auxiliary systems for the absorption cooling application for two different cases when the solar energy was insufficient. Temperature variations were recorded for the absorption machine components, the test room, and the outdoors. The cooling energy, thermal energy, and daily average coefficient of performance (COP) of the absorption system were calculated for two days. Solar absorption cooling was considered for two different auxiliary systems and is presented in this manuscript. The results showed that the daily average COP of the absorption system was 0.283 for Case 1 and 0.282 for Case 2. For both cases, the interior energy storage of the absorption system enabled it to satisfy the cooling demand during the night while solar energy was not available

AN INVESTIGATION OF THE EFFECTS OF AIR VELOCITY AND MOVEMENT ON THE THERMAL COMFORT INSIDE AN AUTOMOBILE

In this study, heat loss from various parts of human body, generated sweat mass and skin wetness depends on this are determined and their effect on thermal comfort are investigated. In the model human body is examined as divided into 16 parts and heat and mass transfer from each parts is simulated, as air flow velocity over the surface and thermal and evaporation resistance of clothing are accounted for the model. After checking the validity of the model (in comparison with results as an experimental study) heat transfer coefficients, sensible and latent heat loss, skin wetness and variations of predicted percentage of dissatisfied (PPD) are investigated for various air velocities, air temperatures and clothing groups. It is included that, average skin wetness decreases with increasing air velocity and sensible and latent heat losses increase due to the increase in heat transfer coefficient with increasing air velocity. However increase in sensible heat loss is more than latent heat loss. The most sensitive parameter to the air velocity is PPD

THERMAL COMFORT ZONES FORSTEADY-STATE ENERGY BALANCE MODEL

In this study, the various thermal comfort parameters including temperature, relative humidity, air velocity, metabolic activity and clothing resistance and their effect to each other are examined. The heat transfer equations given for steady state energy balance between body and environment and the empirical equations which give thermal comfort and physiological control mechanisms of body are used. According to the ASHRAE Standard 55-1992, an environment can be assumed comfortable while Predicted Percentage of Dissatisfied (PPD) is less than % 10. Considering this, thermal comfort zones in various conditions are studied and results are presented and discusse