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In the present experiment, a computerized single cylinder diesel engine with a data acquisition system was used to study the effects of oxygen enriched combustion technology (OECT) on the performance characteristics. The use of different levels of oxygenenriched air was compared with respect to percentage load. Increasing the oxygen content in the air leads to faster burn rates and increases the combustibility at the same stoichiometry (oxygen-to-fuel ratio). These effects have the potential to increase the thermal efficiency and specific power output of a diesel engine. The power increases considerably with oxygen enrichment. In addition, oxygen enrichment can also be considered as a way to reduce the sudden loss in power output when the engine operates in a high load condition. Assessed high combustion temperature from the oxygen enriched combustion leads to high combustion efficiency. OECT reduces the volume of flue gases and reduces the effects of greenhouse effects. Engine tests were conducted in the above said engine for different loads and the following performance characteristics like brake power (BP), specific fuel consumption (SFC), mean effective pressure, brake thermal efficiency, mechanical efficiency, and exhaust gas temperature were studied. The objective of this paper is to address, in a systematic way, the key technical issues associated with applying OECT to single cylinder diesel engines.

Problem statement: There are two types of global warming contributions through refrigeration and air conditioning systems. The first one is the Direct Global Warming Potential (DGWP) due to the emission of refrigerants and their interaction with heat radiation. The second one is the Indirect Global Warming Potential (IDGWP) due to the emission of Carbon Dioxide (CO₂) by consuming the energy that is generated through the combustion of fossil fuels. Most of refrigerants used in vapor Compression system were Chlorofluorocarbon (CFCs) and Hydro Chlorofluorocarbon (HCFCs) which contains chlorine and if any leakage in the system, these gases will go up and reach stratosphere. The chlorine atoms in the gases will act as a catalyst to destroy ozone layer and cause ozone depletion which causes health hazards, global warming, melting of polar ice caps and drought. Hence, it is necessary to minimize the Global warming and Ozone depletion. The refrigerant R22 widely used in the air-conditioners is a major Contributor of Chlorofluorocarbons (CFCs) which cause irreparable loss to the ozone layer and has to be replaced. Approach: To conserve the energy and minimize the global warming, the systems should be designed as more energy efficient and also to minimize Ozone depletion, the eco friendly refrigerants are to be selected and tested as alternative refrigerants to R22. Hence, a window air conditioner of 3.5 kW capacity fitted with Electronic Expansion Valve (EEV)) instead of capillary tube as an expansion device, was tested for its performance with the selected eco friendly refrigerants R407C and R290 as an alternative to R22 under fixed indoor and outdoor chamber temperatures in the experimental set up and varying the EEV opening. Results: It has been observed from the experimental studies that when the smaller capacity R22 window air conditioner with EEV is retrofitted with R407C and R290, compared to the performance given by R22, the Coefficient Of Performance (COP) given by R407C and R290 is improved in the range of 4.8-7.1 and 8.0-12.3% respectively and the Energy Efficiency Ratio (EER) is increased by 4.2-6.9% for R407C and 6.4-10.8% for R290. Conclusion: The performance of Electronic Expansion Valve (EEV) with eco friendly refrigerant R290 in the given air conditioner shows a positive effect in terms of COP and energy efficiency and enables the industry to favorably displace the R22 and other types of expansion devices

Problem statement: Diesel engine emits more pollutants to atmosphere causing air pollution. This necessitates the search of a renewable alternate fuel which is environment friendly. The objective of this research was to investigate the environmental aspects of pongamia bio-fuel in a single cylinder diesel engine with the influence of fuel injection pressure. Approach: Bio-fuel was prepared from non-edible Pongamia pinnata oil by transesterification and used as a fuel in C.I engine. The effect of fuel injection pressure on the engine emission characteristics of a single cylinder direct injection diesel engine has been experimentally investigated using pongamia pinnata methyl ester and its blends with diesel fuel from 0-30% with an increment of 5% at full load. The tests were conducted at five different injection pressures (190, 200, 210, 220 causes better atomization with improved engine emission characteristics for diesel and blends at full load. Moreover blend B5 showed best results at 220 KN m −2 injection pressure.

The objective of this study is to investigate the influence of Electronic Expansion Valve (EEV) on the performance of window air conditioner retrofitted with R407C and R290. The window air conditioner applying the EEV is tested by varying the compressor inlet superheat from 0?C to 20?C. The eco friendly refrigerant R407C has the similar thermodynamic properties as those of R22 with an exception of temperature gliding during the phase change at constant pressure. R290 is a hydrocarbon which also exhibits properties very close to R22 which enables this to be used as a potential alternative to R22.The EEV affords a precise, fast, and stable flow control for a wide range of flow rate due to its use of an electronic control method based on an advanced control algorithm.EEV controls the refrigerant flow through the evaporator by means monitoring pressure and temperature at the outlet of the evaporator and hence it shows good overall performances comparing the capillary tube system. The Coefficient of Performance (COP) of R290 is the maximum among the three refrigerants tested and also for all the three refrigerants, COP is low at higher degree of superheat.