Effect of mass recovery evaporator temperature and condenser temperature on the performance of a solar adsorption-based desalination plant

Water scarcity increases alarmingly as the population increases. Over the years, a number of salt water desalination techniques have been proposed and reached limitations. The requirement of minimum energy is very well satisfied by an adsorption system, since it can operate with low-grade energy and waste heat exhaust from most industries. The first part of this work discusses the effect of condenser and evaporator temperatures on the performance of silica-gel adsorption cycle mathematically. The second part discusses the performance variations due to mass recovery in the two-bed adsorption system mathematically. It was found that the reduction in condenser temperature and increase in the evaporator temperature both increase the fresh water productivity and cooling capacity of a plant. A desalination plant with mass recovery assistance is superior in performance than the conventional plant. Portable water productivity of 8?m³/day/ton is achieved with the condenser temperature of 15°C and the evaporator temperature of 30°C.     

燃气热泵仿真研究

以天然气发动机驱动的压缩式水-水热泵系统为例,建立其各部件数学模型,包括天然气发动机、压缩机、板式蒸发器、板式冷凝器、热力膨胀阀、发动机水套换热器和排烟换热器等的数学模型。利用该模型,研究了不同转速下的热泵系统特性和整体性能特性,与试验结果进行对比,二者吻合良好,证明了燃气热泵系统具有较好的部分负荷特性及较好的节能环保效果。     

A comparative study of performance and combustion characteristics of a CI diesel engine fuelled with B20 biodiesel blends

This paper aims to study the diesel engine performance and combustion characteristics fuelled with Banalities aegyptiaca oil methyl ester, palm oil methyl ester, sesame methyl ester oil, rapeseed methyl ester oil, soybean oil methyl ester and diesel fuel. In this present work, only 20% of each biodiesel blends was tested in diesel engine; stated that the possible use of biodiesel of up to 20% in a diesel engine without modification in literature. A single-cylinder, auxiliary water-cooled and computer-based variable compression ratio diesel engine was used to evaluate their performance at constant speed and at measured load conditions. The performance and combustion tests are conducted using each of the above test fuels, at a constant speed of 5000?rpm. Thus, the varying physical and chemical properties of test fuels against pure diesel are optimised for better engine performance.

Abbreviations: BP: brake power; BSFC: brake-specific fuel consumption; BTE: brake thermal efficiency; CO: carbon monoxide; CP: cylinder pressure; DP: diesel pressure; EGT: exhaust gas temperature; HC: hydrocarbon; HRR: heat release rate; NO _x : nitric oxides; PM: particulate matter; TDC: top dead centre; VCR: variable compression ratio     

Performance,emission and combustion characteristics of an Indica diesel engine operated with Yellow Oleander (Thevetia peruviana) oil biodiesel produced through hydrodynamic cavitation method

The present work deals about the performance, emission and combustion characteristics of a four-cylinder, direct injection, water-cooled, Indica diesel engine fuelled with biodiesel produced through the hydrodynamic cavitation method from an underutilised and potential feedstock Yellow Oleander (Thevetia peruviana) oil. Engine tests were performed with neat diesel and biodiesel blends of 10%, 20% and 30% from Yellow Oleander oil at different engine speeds. Experimental results showed that biodiesel produced through the hydrodynamic cavitation technique with a 1%?w/w catalyst percentage, 6:1?molar ratio and 35?min reaction time was equal to 97.5%. During engine performance tests, biodiesel blends showed higher brake-specific fuel consumption, brake thermal efficiency (for lower blends up to 20%) and exhaust gas temperature than diesel fuel. Engine emissions showed higher nitrogen oxide, but a decreased amount of smoke opacity, carbon monoxide, unburned hydrocarbon and favourable p–θ diagram as compared to diesel.     

Experimental mitigation of NO x emission in exhaust gases of CI engine fuelled with methyl ester of cottonseed oil blend

ABSTRACT

This paper discusses the development of a B20 cottonseed oil blend for passenger vehicle with vanadium-based Selective Catalytic Reduction (SCR) technology addition on exhaust system. SCR is a progressive emissions governor technology organism that injects a liquid-Urea (also called aqueous urea, Ad Blue or Diesel Exhaust Fluid) through an injector nozzle into the exhaust manifold of diesel engine. The methyl ester of cottonseed oil blend was analysed in a single cylinder, 4-stroke, computerised water-cooled, diesel engine of 5.2?kW rated power for performance and emission characteristics with SCR. The results indicate that the emissions of the CI engine running on B20 blend with the catalytic convertor reduced NO _x emission up to 76% with different quantity of dosing. However, it is noted that the brake thermal efficiency is reduced slightly by 2% for SCR due to the back pressure created by the SCR system.     

The effect of exhaust gas recirculation on performance and emission characteristics of HCCI engine

In this work, performance and emission characteristics tests are conducted on homogeneous charge compression ignition (HCCI)-mode engine using mango seed methyl ester. And also the effect of exhaust gas recirculation (EGR) on performance and emission of HCCI engine is analysed. The three different percentages of EGR were added with intake fresh air at 15%, 30% and 45%. The objective of this work is to obtain the optimum EGR percentage based on engine performance and emissions. The brake thermal efficiency (BTE) slightly increased than conventional unmodified direct injection (DI) diesel engine. 15% of EGR shows higher BTE than other percentages of EGR added with HCCI engine. Specific fuel consumption of HCCI-mode engine is lower than the normal diesel engine. The exhaustion of harmful emission of oxides of nitrogen has been reduced when biodiesel is used in HCCI-mode engine. However, smoke and CO emissions were reduced in HCCI-mode engine compared with DI diesel engine and further decreased by using EGR in HCCI-mode engine. HC emissions are slightly increased for HCCI-mode engine.     

Artificial neural network-based prediction of performance and emission characteristics of CI engine using polanga as a biodiesel

The present work predicts the performance parameters, namely brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), peak pressure, exhaust gas temperature and exhaust emissions of a single cylinder four-stroke diesel engine at different injection timings and engine load using blended mixture of polanga biodiesel by artificial neural network (ANN). The properties of biodiesel produced from polanga were measured based on ASTM standards. Using some of the experimental data for training, an ANN model was developed based on standard back-propagation algorithm for the engine. Multi-layer perception network was used for non-linear mapping between input and output parameters. Different activation functions and several rules were used to assess the percentage error between the desired and the predicted values. It was observed that the developed ANN model can predict the engine performance and exhaust emissions quite well with correlation coefficient (R) 0.99946, 0.99968, 0.99988, 0.99967, 0.99899, 0.99941 and 0.99991 for the BSFC, BTE, peak pressure, exhaust gas temperature, NO_x, smoke and unburned hydrocarbon emissions, respectively. The experimental results revealed that the blended fuel provides better engine performance and improved emission characteristics.     

Experimental investigation of compression ignition engine fuelled by a catalytic fuel reformer

Waste engine oil (WEO) as an alternative fuel for compression ignition (CI) engine is investigated in this study. WEO was thermally cracked with alumina catalyst in the catalytic fuel reformer (CFR). The gas obtained from the CFR was condensed using a water-cooled condenser for analytical purposes. The output of the condenser was named as WEOA (reformulated WEO with alumina catalyst). The different chemical properties of WEOA were analysed. The compositional analysis for diesel and WEOA was made using Fourier transform infra-red (FT-IR) and gas chromatography–mass spectrometer (GC–MS). The experimental investigation was conducted in a single-cylinder diesel engine and the performance and emissions were compared with those of diesel fuel. Experimental results concluded that the performance and emission level are better than those of diesel fuel. This study concludes that environmentally hazardous waste material such as WEO is recycled and converted into a useful resource and serves as an alternative source of fuel for CI engine.     

Influence of injection timing on engine performance,emission characteristics of Mimusops Elangi methyl ester

ABSTRACT

The improvement in engine performance and exhaust emissions reduction are the major important issues in developing a more efficient engine. The injection timing is one the major parameters that affect the engine performance and emissions for a diesel engine. The present work focused on characterising the in?uence of injection timing on engine performance and exhaust emissions. This has been critically investigated for B20?+?25?ppm (20% Mimusops Elangi methyl ester-80% diesel fuel?+?25?ppm of TiO₂ nanoparticle) additive as alternative fuel. The B20?+25 ppm TiO₂ nanoparticle additive produces more HC and CO emission, but reduce NO_X emission when injection timing is retarded. Advancement in injection timing for B20?+25?ppm TiO₂ nanoparticle additive results in an increase of brake thermal efficiency, decreases brake specific fuel consumption and giving out less HC, CO, smoke emissions but the marginal increase in the NO_X emission.     

Effect of exhaust gas recirculation on a nanoparticle-doped biodiesel- and diesel-blends-fuelled diesel engine

ABSTRACT

This work investigates the effect of adding Cerium oxide nanoparticles at different proportions (30, 60 and 90?ppm) to Calophyllum inophyllum methyl ester and diesel blends (20% CI methyl ester and 80% diesel) in a four-stroke single-cylinder diesel engine. Addition of nanoparticles is a strategy to reduce emission and to improve the performance of the biodiesel. Modified fuels are introduced into the engine by admitting exhaust gas recirculation (EGR) at a rate of 10% and 20% so as to reduce nitrogen oxide (NO_X) emissions from biodiesel and diesel blends. Results revealed a significant reduction in emissions (CO, NO_X, HC and Smoke) at a 10% EGR rate. However, brake thermal efficiency is reduced with an increase in brake-specific fuel consumption at higher EGR rates. Hence, it is observed that 10% EGR rate is an effective method to control the emission of biodiesel and diesel blends without compromising much on engine efficiency.     

Thermodynamic analysis of compression ignition engine using neat Karanja oil under varying compression ratio

Exergy analysis method has been widely used to evaluate the energy utilisation efficiency and potential of waste heat energy. The objective of the present investigation is to analyse the exergy efficiency, destruction of exergy, mean gas temperature, exhaust temperature, brake thermal efficiency and brake-specific fuel consumption of a single cylinder diesel engine using diesel and neat Karanja oil blends at different compression ratios (CRs) at full load and at different loads with a CR of 18. It is observed that 10% neat Karanja oil blend (K10) shows similar performance to diesel and better than 20% neat Karanja oil blend (K20). But K20 shows better performance at a CR of 18 as compared to 16. At higher loads, exergy efficiency and destruction of exergy are found more at a CR of 18 for all fuels. Destruction of exergy decreases and exergy efficiency increases at CR 18.     

A neural network model for the prediction of compression ignition engine performance at different injection timings

Rapid depletion of fossil fuel and continuous increase in gasoline prices have stimulated the search of alternative fuels. This paper deals with the prediction of engine performance, emission and combustion characteristics of compression ignition engine fuelled with fish oil biodiesel using artificial neural network (ANN). Experimental investigations are carried out in a single cylinder constant speed direct injection diesel engine under variable load conditions at different injection timings?21⁰, 24⁰ and 27⁰ bTDC. The performance, combustion and emission characteristics are measured using an exhaust gas analyser, smoke meter, piezoelectric pressure transducer and crank angle encoder for different fuel blends and engine load conditions. For training the neural network, feed-forward back propagation algorithm is used. The developed ANN model predicts the performance, combustions and exhaust emissions with a correlation coefficients (R) of 0.97–0.99 and a mean relative error of 0.62–4.826%. The root mean square errors are found to be low. The developed model has found to predict accurately the engine performance, combustion and emission parameters at different injection timings.     

Investigation of the effects of exhaust and power loss in dual-fuel six-stroke engine with EGR technology

ABSTRACT

In today’s world, the usage of internal combustion engines is inevitable. Particularly the diesel engines find their importance more than the petrol engines due to their operating cost. But diesel engines have their demerits in the area of exhaust and power loss. Necessary steps have to be taken in order to effectively use the fuel available. In this technical presentation, we have discussed about the utilisation of six-stroke engines which run on dual fuel. The six-stroke engine’s principle resembles a double-stage compressor. By this way, effective compression is done and the need for turbocharger is completely neglected. We have also considered cylinder’s position in a six-stroke engine. As the lubrication and cooling system needs special attention in the case of opposing-type cylinders, we have formulated a better and simple arrangement in which same power is produced, eradicating the lubrication problems. Also, the pollution (NOx) emitted by the diesel engines is also taken into account. We found the solution in the form of dual-fuel and exhaust gas recirculation system. The combusting temperature of the diesel engine is above 2000°F and this is the prime reason for NOx emission. So an alternative fuel which can be combusted below the level of diesel should be used. Moreover, the availability and production cost must be taken into consideration. We found ethanol as a better alternative for diesel. The cold starting of the engine is made easier using a glow plug, which is used to preheat the charge coming inside the combustion chamber.     

Artificial neural network approach to predict the engine performance of fish oil biodiesel with diethyl ether using back propagation algorithm

An artificial neural network (ANN) model is developed to predict the engine performance of fish oil biodiesel blended with diethyl ether. Engine performance and emission characteristics such as brake thermal efficiency, hydrocarbon, exhaust gas temperature, oxides of nitrogen (NO_x), carbon monoxide (CO), smoke and carbon dioxide (CO₂) were considered. Experimental investigations on single-cylinder, constant speed, direct injection diesel engine are carried out under variable load conditions. The performance and emission characteristics are measured using an exhaust gas analyser, smoke metre, piezoelectric pressure transducer and crank angle encoder for different fuel blends and engine load conditions. In this model, a back propagation algorithm is used to predict the performance. Computational results clearly demonstrated that the developed ANN models produced less deviations and exhibited higher predictive accuracy with acceptable determination correlation coefficients of 0.97–1 and mean relative error of 0–3.061% with experimental values. The root mean square errors were found to be low. The developed model produces the idealised results and it has been found to be useful for predicting the engine performance and emission characteristics with limited number of available data.     

单片机在柴油机废气再循环系统中的应用

介绍了柴油机的废气再循环技术 ,为有效降低柴油机的氮氧化物排放 ,在测取废气再循环率脉谱的基础上 ,设计了单片机实现其功能的硬件电路和系统软件 .     

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.     

太阳能热泵供热系统性能的试验研究

对太阳能热泵系统的不同运行工况进行了试验研究。分析了蒸发器入口水温、冷凝器入口水温对热泵系统性能的影响。通过研究分析得出:太阳能集热器面积与热泵机组的匹配为影响系统性能的重要参数,应根据用户对热量的需求来选择;蒸发器入口水温可在5℃—20℃之间变化,在20℃时,系统COP最高达到3.6。通过对试验结果的分析,为太阳能热泵系统的设计和运行控制提供了依据。     

Influence of an aqueous cerium oxide nanofluid fuel additive on performance and emission characteristics of a compression ignition engine

Aqueous cerium oxide at the rate of 50cc per liter was dispersed into diesel and diesel–biodiesel using mechanical agitator and an ultrasonicator for preparing the test fuels. Cerium oxide nanomaterials present in the aqueous cerium oxide exhibit higher catalytic activity because of their large contact surface area per unit volume and can react with water at high temperature to generate hydrogen and improve fuel combustion. Also, cerium oxide nanomaterials act as oxygen buffers causing simultaneous oxidation of hydrocarbons (HCs) as well as the reduction of oxides of nitrogen. The neat diesel and test fuels were tested in an engine without changing the engine system at 0%, 25%, 50%, 75% and 100% load condition and resulted in a considerable enhancement in the brake thermal efficiency, improved brake-specific fuel consumption and decreased concentration of HC, NO_x and smoke in the exhaust emitted from the diesel engine due to incorporation of aqueous cerium oxide in the test fuels.     

热泵热回收新风机在寒冷地区的实验研究

为解决寒冷地区冬季空气源热泵运行效率、新风机冻损等运行问题,保证冬季室内良好的空气品质,设计了在冬季将排风引入热泵蒸发器,通过热交换回收排风的能量,并利用热泵冷凝器加热引入室内新风的热泵热回收新风机。采用空气焓差法对该机组在利用排风及排风混室外空气2种运行工况下的制热量、输入功率、热泵能效比(COP)、热回收效率的对比实验。用热泵热回收新风机引进新风后基本没有改变机组输入功率,相同环境条件下的制热量增加,COP值增大,焓差热回收效率最高可达到51.4%。新风机和热泵相结合,利用排风余热提高热泵蒸发器工作温度,改善了热泵和新风机在北方寒冷地区冬季的运行性能。     

Development and experimental validation of a high-temperature heat pump for heat recovery and building heating

The performance of a high-temperature heat pump unit using geothermal water for heat recovery in buildings is experimentally evaluated. The unit consists of a twin-screw refrigeration compressor, a condenser, an evaporator and an oil cooling system. The effect of the cooled oil temperature on the performance of the heat pump unit is experimentally investigated. Results show that the unit stably produces outlet hot water at a constant temperature of 85 °C and performs well in a wide range of high-temperature conditions with a high energy efficiency ratio. The results also indicate that the key to improving the performance of a high-temperature heat pump unit often depend on the selection of proper cooled oil temperature. The optimum cooled oil temperature is 50-65 °C when the condensing temperature is above 70 °C. At these temperatures, the oil cooling system can increase the energy efficiency ratio of the heat pump by 6.3%.