Experimental investigation of compression ratio on performance and emissions characteristics of pumpkin seed oil blends in a diesel engine

This aim of the current study is to evaluate the performance and emission characteristics of pumpkin seed oil with diesel at different blended ratios (B10-CR15, B20-CR15, B10-CR18 and B20-CR18) in a constant speed (1500?rpm) engine. The tests were conducted at various loads of the engine and with specific compression ratios of 15 and 18. The performance and emissions were compared with the different blend ratios and compression ratios. As a result of which the higher compression ratios shows better performance and emission than the lower compression ratio; among them B20-CR18 shows better results such that CO₂, HC and CO emissions were reduced and there is a slight increase in NO_X value compared to diesel and other blend ratios and also there is an increased brake thermal efficiency for the blend B20-CR18. This shows that the optimum blend is chosen from the results is identified as B20-CR18, which has better performance and emission than other blends and compression ratios.     

Energy and exergy analysis of compression ignition engine fuelled with rice bran biodiesel blends

The present study aims to investigate a four-stroke single cylinder, water-cooled compression ignition (CI) engine coupled with an eddy current dynamometer. The rice bran oil biodiesel blends of B10, B20, B30 and pure diesel are tested for its performance in the engine. Energy and exergy analysis is carried out for the biodiesel blends and pure diesel. The experimental data were collected using steady-state tests which enable accurate measurements of air, fuel and cooling water flow rates, engine load and all the relevant temperatures. The performance parameters, energy and exergy efficiencies were computed for each fuel operation and compared with each other. The energy and exergy analysis has made to find input availability, brake power availability, cooling water availability and exhaust gas availability. From the exergy analysis, component of major exergy destruction was found. Balances of energy and exergy rates for the engine were also computed.     

Evaluation of diesel engine performance using diesel–cashew nut shell oil blends

The performance, emission and combustion characteristics of a single-cylinder, direct injection diesel engine was studied at various loads at a constant speed of 1500?rpm with neat diesel and cashew nut shell oil (CNSO) blends. Among all the blends, 20% CNSO blend, showed better performance compared to all the other blends. Also, it has been found that CNSO blends can be used in the available diesel engine without making any modification.     

Energy and exergy analysis of a CI engine using tyre pyrolysis oil blends with diesel

Tyre pyrolysis oil (TPO) blend with diesel can be used as an alternate fuel. Tests have been carried out to analyse the energy and exergy characteristics of diesel engine fuelled by B10, B20 and B30 blend of TPO with diesel fuel. TPO was derived from waste automobile tyres through vacuum pyrolysis process (batch type). In this paper, the brake thermal efficiencies of TPO of different blends (10%, 20% and 30%) are compared with the pure diesel and discussed. Further, exergy and energy values of TPO–diesel with different blends are analysed.     

The influence of bio additive on the compression ignition engine with diesel and Jatropha methyl ester biodiesel

The present experimental investigation evaluates the effects of using blends of diesel fuel with 20% concentration of Methyl Ester of Jatropha biodiesel blended with bio additive. Both the diesel and biodiesel fuel blend was injected at 23° Before Top Dead Centre to the combustion chamber. The experiment was carried out with three different ratios of bio additive. Biodiesel was extracted from Jatropha oil; 20% (B20) concentration is found to be best blend ratio from the earlier experimental study. The bio additive was added to B20MEOJ at various concentrations of 1?ml, 2?ml and 3?ml, respectively. The main objective is to obtain minimum specific fuel consumption, better efficiency and lesser Emission using bio additive blends. The results concluded that full load shows an increase in efficiency when compared with diesel, and highest efficiency is obtained with B20MEOJBA 3?ml bio additive blend. It is noted that there is an increase in thermal efficiency as the blend ratio increases. Biodiesel blend has a performance closer to that of diesel, but emission is reduced in all blends of B20MEOJBA 3?ml compared to that in diesel. Thus the work marks for the suitability of biodiesel blends as an alternate fuel in diesel engines.     

Thermodynamic studies and parametric effects on exergetic performance of a steam power plant

A comprehensive thermodynamic analysis is conducted for an existing 82?MW steam power plant. A detailed assessment on energy loss and exergy destruction for individual components of plants (including boiler sub-parts) is reported. A code is built in EES to evaluate the energy loss, energy efficiency, physical and chemical exergies, exergy efficiency and exergy destruction for each part of plant by considering the real values’ range of operating parameters. Analysis pointed out that the main sources of exergy destruction are boilers followed by the turbines, deaerators and then condensers. In boiler, combustor contributes about 50% in total exergy destruction. The maximum energy loss is reported in boilers followed by condensers, in piping, due to friction and in turbines. The exergy efficiency procured about 42% for boilers, 84% for turbines, 38% for condenser, and 60% for deaerators, respectively. The effects of crucial working parameters on plant performance are analysed.     

Performance of a twin cylinder dual-fuel diesel engine using blends of neat Karanja oil and producer gas

In the present study, performance and emission analysis are done in a twin cylinder four-stroke dual-fuel diesel engine in two cases of operation. In the first case, the engine is tested using diesel, K10 (10% neat oil+90% diesel) and K20 (20% neat oil+80% diesel) in single mode and in the dual-fuel mode with an optimum producer gas flow rate of 21.49 kg/h under different load conditions. In the second case, the engine is tested using the same test fuels in the dual-fuel mode at different gas flow rates under a constant load of 10 kW. The study reveals that the dual-fuel operation of all test fuels shows a lower engine performance and better control of smoke and oxide of nitrogen emission compared with their single-mode operation under all load conditions. Whereas other emission parameters such as carbon monoxide, carbon dioxide and hydrocarbon are at a higher level.     

Performance and emission characteristics of a diesel engine fuelled by neem oil blended with alcohols

Fuel crisis and environmental concerns have led researchers to look for alternative fuels of bio-origin sources such as vegetable oils, which can be produced from forests and oil-bearing biomass materials. Vegetable oils have energy content comparable to that of diesel fuel. Straight vegetable oils posed several operational problems and durability problems when subjected to long-term usage in compression ignition engine. These problems are attributed to higher viscosity and lower volatility. In this study, performance and emission parameters of a diesel engine operating on neem oil and its blends of 5, 10, 15 and 20?vol% with ethanol, 1-propanol, 1-butanol and 1-pentanol are evaluated and compared with diesel operation. The results indicate that the brake thermal efficiency is improved with the use of neem oil–alcohol blends with respect to those of neat neem oil. The smoke intensity, CO and HC emissions with neem oil–alcohol blends are observed to be lower with respect to those of neat neem oil at higher loads. The NO _x emission is very slightly reduced with the use of neem oil–alcohol blends except for the neem oil–ethanol blend compared with that of neat neem oil.     

Thermodynamic analysis of low-grade solar heat source-powered modified organic Rankine cycle using zeotropic mixture (Butane/R1234yf)

This paper communicates detailed energy and exergy analysis of low-grade energy resource of solar-powered organic Rankine cycle (ORC) integrated with both the internal heat exchanger and open feed water heater, ORC incorporated with the internal heat exchanger, with open feed water heater and basic ORC, respectively. Results indicate that highest first law efficiency (11.9%), exergetic efficiency (51.88%) and lowest exergy destruction (1749?kW) are obtained for ORC integrated with both internal heat exchanger and open feed water heater among other considered ORCs. Moreover, zeotropic mixture (butane/R1234yf) shows better first law and exergetic efficiency and lower exergy destruction than pure fluid.     

Experimental studies on the performance,emission and combustion characteristics of a biodiesel-fuelled (Pongamia methyl ester) diesel engine with diethyl ether as an oxygenated fuel additive

This paper investigates the combustion, performance and emission characteristics of a single-cylinder diesel engine using neat biodiesel (Pongamia methyl ester) with two different blends (10% and 15% diethyl ether [DEE]) at different load conditions. The measured values of brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), exhaust gas temperature (EGT), carbon monoxide (CO), hydrocarbon (HC), nitrogen oxide (NO) and smoke were calculated and analysed and compared with diesel fuel. The results showed that a significant reduction in NO and smoke emissions for neat biodiesel with 15% DEE blend compared with neat biodiesel at full load conditions. The peak pressure and heat release rate were decreased, and maximum rate of pressure rise and ignition delay were also decreased with DEE blends at full load. On the whole, it is concluded that the biodiesel with 15% DEE blend showed better results with respect to efficiency and emissions point of view compared with biodiesel.     

Performance characteristics of palm kernel biodiesel and its blend in a CI engine

The full load performance characteristics of a diesel engine fuelled with palm kernel biodiesel and its blend with diesel fuel are presented in this paper. The biodiesel was synthesised from Nigerian palm kernel oil through a direct base catalysed transesterification process using sodium hydroxide and methanol as the catalyst and alcohol, respectively. The produced biodiesel was blended with neat diesel fuel at a ratio of 20% biodiesel to 80% diesel by volume. The engine torque, brake power, brake specific fuel consumption and brake mean effective pressure were determined for each of the fuels at 400 rpm intervals between 1200 and 3600 rpm. In other to establish a baseline for comparison, the engine was first run on neat diesel. The test results interestingly revealed that the fuel blend (B20) produced higher torque at low and medium engine speeds than neat diesel fuel and unblended biodiesel (B100). This suggests that it can be a suitable fuel for heavy duty engines that are required to develop high torque at low engine speeds. It was also observed that diesel fuel developed higher torque and brake power than the unblended biodiesel (B100) at all tested speeds and showed the least brake specific fuel consumption possibly because of its higher heating value. In all, the palm kernel biodiesel and its blend (B20) exhibited performance characteristic trends very similar to that of diesel fuel thus confirming them as suitable alternative fuels for compression ignition engines.     

Experimental investigations on a variable compression ratio (VCR) CIDI engine with a blend of methyl esters palm stearin-diesel for performance and emissions

The present work deals with an experimental evaluation of the existing diesel engine with a blend of methyl esters of palm stearin (PS) oil and petro-diesel under varying injection pressures and compression ratios (CRs). It was observed that the brake thermal efficiency of engine was high with PSME40 at an injection pressure of 210 bar and CR of 16.5 when compared to other fuel injection pressures of 190 and 230 bar. However, the engine performance was superior with CR 19 at the rated injection pressure of 190?bar. Higher peak pressures are observed with higher CR. The engine emissions in terms of hydrocarbons, carbon monoxide and smoke opacity were lower but the nitrogen oxides were found to be increased due to the better combustion. It is observed that CR and fuel injection pressure simultaneously played a vital role in the reduction of emissions. The study revealed that PS could be explored as a source for producing biodiesel effectively with environmental concerns.     

Performance characteristics of CI engine using blends of waste cooking oil methyl ester,ethanol and diesel

ABSTRACT

The main emphasis of this work is to explore the biodiesel obtained from waste cooking oil and its utilisation in CI engine blended with ethanol and conventional diesel. Waste cooking oil methyl esters (WCOME) was prepared by transesterification with a heterogeneous catalyst such as CaO. Diesel and WCOME blends of five different proportions with 5% of ethanol uniformly added to them were used as a fuel in a variable compression ratio, constant speed, compression ignition engine. The performance, emission and combustion characteristics of the engine at part and full load conditions were compared with that of neat diesel, varying the compression ratio from 18 to 22. From the experimental results, the blend comprising 20% waste cooking oil, 5% ethanol and 75% mineral diesel showed ameliorated performance and emission characteristics, compared with all the other fuel blends at an optimum compression ratio of 21.     

地下含水层储能系统的(火用)分析

探讨了地下含水层储能系统回灌期输入地下含水层的能量、火用及抽水期从地下含水层回收的能量、火用的计算公式。通过算例,计算了大流量、低回灌水温度,小流量、高回灌水温度及适中的流量、回灌水温度的3种工况的储能效率及火用效率,小流量、高回灌水温度运行模式的火用效率最高。将水泵消耗的电能计入火用效率,对火用效率进行修正,小流量、高回灌水温度运行模式具有更大的优势。     

电压缩式制冷循环与吸收式制冷循环的热力学比较分析

采用效率与损失分析方法,计算比较了电压缩式制冷循环与单效吸收式制冷循环的效率及两种制冷循环在典型工况下各环节的损失。结果表明,当采用合适的发生器温度和热源温度时,两种制冷循环的效率基本相同;电压缩式制冷循环的主要损失发生在压缩机环节,吸收式制冷循环的主要损失发生在吸收器和发生器。讨论了两种制冷循环的改进途径。     

蒸发冷却与机械制冷复合空调机组分析

对蒸发冷却与机械制冷复合空调机组进行了(火用)分析,并根据实测数据计算出了机组各功能段进出口(火用)的大小,并通过(火用)效率和(火用)效比分析得出了复合空调机组能量利用效率低的薄弱环节,提出了节能改进方法.     

Performance and emission characteristics of a low heat rejection engine using Nerium biodiesel and its blends

In the present study, the surface of cylinder head, piston, exhaust and inlet valves of a four stroke direct injection and single cylinder diesel engine has been coated with partially stabilised zirconia (PSZ) by the plasma spray method. The coated engine was tested with the neat diesel and methyl ester of neat Nerium oil. The performance and emission results were compared with the uncoated engine fuelled with diesel and methyl ester of Nerium oil (MEON). Specific fuel consumption of the PSZ-coated engine was lower at all loads, because of the insulation effect of coating and changes in combustion process due to coating. The brake thermal efficiency of PSZ-coated engine fuelled with MEON is 3.8% higher than uncoated engine fuelled with MEON. The emission for the PSZ-coated engine with diesel was improved compared with uncoated engine except NO_x.     

CO_2套管式气冷器用能效率的热力学第二定律分析

利用1台安装有套管式换热器的跨临界CO_2制冷系统实验台,改变CO_2质量流量、高压侧压力及气冷器冷却水流量,通过实验测得气冷器中CO_2和冷却水沿管长方向的温度分布,并计算气冷器沿管长方向的熵产、火用正文损和火积分布,对气冷器的用能效率进行分析。结果表明,在多种工况下,熵产、火用损和火积耗散均沿管长逐渐降低;熵产和火用损均随CO_2质量流量的增大而降低,而随高压侧压力的升高而增大;质量流量对火积耗散无明显影响。     

空调系统中热湿处理过程的(火用)评价方法及应用

提出对热、湿处理过程进行单独(火用)评价的概念,并构建了相应评价指标.以某一次回风空调系统的典型夏季空气处理过程为例,在热力学极限意义上阐明了对热、湿处理进行单独(火用)评价的实施过程,计算结果表明该空气处理过程的显热(火用)效明显高于潜热(火用)效,潜热(火用)效低下的原因主要在于再热显热(火用)损和冷凝水(火用)损...     

Evaporation rate and engine performance analysis of coated diesel engine using Raphanus sativus biodiesel and its diesel blends

An experimental investigation to measure the evaporation rates, PSZ-coated engine performance and emissions of radish biodiesel (Methyl Ester of radish oil) and its blends in different volumetric proportions with diesel is presented. The thermo-physical properties of all the fuel blends have been measured and presented. Evaporation rates of neat radish biodiesel, neat diesel and their bends have been measured under slow convective environment of air velocity of 0.2?m/s with a constant temperature of 200°C. Evaporation constants have been determined by using the droplet regression rate data. The neat fuels and fuel blends have been utilised in a test engine with different load conditions to evaluate the performance and emission characteristics of the fuels. From the observed evaporation, performance and emissions characteristics, it can be suggested that a blend of B25–B75 could be optimally used in coated diesel engine settings without any modifications on it.