S.K. Tyagi

Thermodynamics and performance evaluation of encapsulated PCM-based energy storage systems for heating application in building

This communication presents the comparative study of two different types of thermal management systems for room’s heating applications using calcium chloride hexahydrate as the thermal energy storage material encapsulated in panels and balls. During the daytime, TMS was outside the test room to store the solar heat in TMS. The solar heat made available to charge the PCM from solid to liquid and to warm the test room throughout the observation period during night time. As the room temperature drops significantly during the night time, so as the level of comfort. Both the thermal management systems have been used to heat the test room during night time and the temperature of the test room has been maintained at thermal comfort level without any conventional source of energy, i.e. using passive system. Also the experimental values were compared with those of the theoretical values and are found in good agreement with each other. Thus, it can be concluded that the experimental study carried out for both the thermal management systems have been validated by theoretical approach or vice versa and hence found to be satisfactory towards the successful operation of these systems.

Experimental investigation of a diesel engine fuelled with Jatropha curcas L. seed oil

Straight vegetable oils pose operational and durability problems. These problems are attributed to high viscosity, low volatility and polyunsaturated characteristics of vegetable oils. The process of transesterification is found to be an effective method of reducing vegetable oil viscosity and eliminating operational and durability problems. This paper deals with the preparation and application of methyl ester of Jatropha curcas L. seed oil. The study was carried out with a single cylinder, direct injection four-stroke diesel engine at a rated speed of 1500 rpm with different loads. The important properties of methyl ester of J. curcas L. seed oil was compared with petroleum diesel. The engine performance was analysed with different blends of biodiesel and compared with petroleum diesel. It was concluded that the lower blends of biodiesel enhance the break thermal efficiency and reduce the fuel consumption. It is proved that the use of biodiesel (produced from J. curcas L. seed oil) in compression ignition engine is a viable substitution of petroleum diesel.

Comparative study of different insulating materials for reducing the heat losses in steam pipes: a technical study

An efficiency loss such as heat loss across bare pipe surfaces reduces the available energy to end-uses and increases the burden on boilers to meet the demand. Energy losses create additional stress on the system that accelerates wear and leads to overloading on the system for which it is not originally designed. In the present study, calculations for heat loss and cost of different insulating materials for varied thicknesses were performed for typical location in Jammu and Kashmir, India. The detailed analysis of the heat loss from bare steam pipes was performed with a view to suggest suitable type of insulation to lower the heat loss to acceptable limits, thereby reducing the cost of fuel. The present work provides the detailed study on the heat conduction analysis of steam pipes for different diameters. This analysis includes the heat loss from steam pipes and cost of insulation for different thicknesses of mineral wool, cement and lead, which can be used as the insulating material. The economics of each insulation type is studied, and the analysis indicates that there is an appreciable fuel saving in terms of thermal units.