4 research outputs found
Investigation into the Impact of Ammonia Hydroxide on Performance and Emissions in Compression Ignition Engines Utilizing Diesel/Biodiesel Blends
In recent times, there has been a surge in scientific endeavors aimed at combating global warming. Various methods have been employed to address this issue, including the substitution of fossil fuels with more environmentally sustainable alternatives and the combination of different fuel types. This can be achieved through the integration of innovative injection systems and the simultaneous combustion of alternative fuels alongside fossil fuels, or by modifying fuel injection systems such as in the PCCI, RCCI, or HCCI systems. In a particular research investigation, a blend of ammonia hydroxide and diesel, with volume percentages of 7.5% and 92.5% respectively, was utilized as green fuels. Various proportions of biodiesel were incorporated into the conventional injection system. Experiments were conducted on a four-stroke, single-cylinder, air-cooled diesel engine with fuel ratios of D80B20N7.5, D60B40N7.5, D40B60N7.5, D20B80N7.5, and pure diesel. The primary objective was to analyze the engine\u27s brake thermal efficiency (BTE) and resulting emissions. Additionally, the study investigated changes in specific fuel consumption (BSFC) and compared the outcomes to those obtained using diesel alone. The study findings revealed that the inclusion of ammonia hydroxide in the blend of diesel and biodiesel in varying volumetric ratios led to an increase in brake thermal efficiency compared to using diesel alone. While the average brake thermal efficiency with pure diesel stood at 20.5%, the introduction of the diesel and biodiesel mixture in different proportions resulted in a decrease in average brake thermal efficiency. However, incorporating ammonia hydroxide at a volumetric percentage of 7.5% into the blend led to an increase in average brake thermal efficiency corresponding to the volumetric percentage employed. The highest brake thermal efficiency of 21.26% was achieved with the D80B20N7.5 mixture. As the percentage of biodiesel increased, there was a subsequent decrease in average brake thermal efficiency. Nevertheless, with the addition of the highest mixture percentage, D20B80N7.5, a brake thermal efficiency of 20.85% was recorded, surpassing the performance of diesel alone
Enhancing Diesel Engine Performance by Directly Injecting Blends of Ammonium Hydroxide and Including Liquid Petroleum Gas as a Partially Premixed Charge
Recently, scientists have made significant strides in addressing or mitigating environmental issues. Researchers have adopted various approaches to tackle these issues, such as replacing fossil fuels with more environmentally friendly alternatives or blending multiple fuel types. This can be achieved by either integrating these two trends through the use of new injection systems and simultaneous combustion of alternative fuels with fossil fuels or by modifying fuel injection systems, exemplified by the PCCI, RCCI, or HCCI systems. Consequently, these methods have proven effective in reducing environmental pollutants, enhancing thermal efficiency, and decreasing specific fuel consumption. In this study, ammonia hydroxide and diesel were utilized as eco-friendly fuels, with volume ratios of 7.5% and 92.5%, respectively. Using the PCCI system, a four-stroke single-cylinder diesel engine underwent varying additions of liquefied petroleum gas (LPG) at rates of two, four, and six liters per minute. This facilitated experimental investigations into the engine\u27s thermal efficiency (BTE) and ambient emissions. Additionally, changes in specific fuel consumption (BSFC) were examined and compared with those when using diesel alone or diesel with ammonia hydroxide in the specified proportion. Moreover, empirical findings indicated that incorporating ammonia hydroxide into diesel at volume ratios of 7.5%–92.5% resulted in a mere 20.98% and 23.95% increase in thermal efficiency, respectively, compared to diesel alone. However, the average brake thermal efficiency improved to 24.6% with the introduction of liquefied petroleum gas at a rate of two liters per minute and escalated to 36.2% at a rate of four liters per minute. The highest braking thermal efficiency, 42.9%, was observed at a 2-kw load when adding LPG at a rate of six liters per minute with an increase in load. Additionally, the investigation monitored parameters such as soot opacity, emissions species, exhaust temperature, and specific fuel consumption
Engine Performance and Emissions Improvement Study on Direct Injection of Diesel/Ammonia Dual Fuel by Adding CNG as Partially Premixed Charge
Researchers have recently moved on in their studies to find a solution to prevent or reduce this problem. There have been directions taken by researchers to solve the problem, including, replacing fossil fuels with environmentally friendly types or by combining two or more types of fuel. This is by modifying fuel injection systems as appears in the PCCI, RCCI, or HCCI systems, or working to integrate the two trends by using new injection systems and burning alternative fuels with fossil fuels. Therefore, the trend has good results on the specific consumption of fuel, raising thermal efficiency, and working to reduce environmentally polluting emissions. This study employed ammonia hydroxide and diesel as a green fuel, with volume ratios of 7.5% to 92.5%, respectively. By adding a variable percentage of compressed natural gas (CNG) (1.5 litres/min - 2.5liters/min) using the PCCI system in a four-stroke single-cylinder diesel engine the experimental studies will performed on the engine thermal efficiency (BTE) and emissions polluting the environment. The change in specific fuel consumption (BSFC) will be discussed and the results will be compared with their counterparts in the case of using diesel only and using diesel with ammonia hydroxide of the mentioned percentage only. The vibration analysis system has been employed to evaluate the actual performance of the engine by measuring the vibration using the Fast Fourier Transform (FFT) approach. Moreover, after practical experiments, we concluded that using ammonia hydroxide with diesel in volume proportions of 7.5% - 92.5%, when compared to diesel only worked to improve thermal efficiency by 20.98%, and 23.95%, respectively. When natural gas is added by 1.5 litres per minute, the thermal efficiency increases to 26.83%, but when it is added at a rate of 2.5 litres per minute, the thermal efficiency increases to 27.45%. The exhaust temperature, specific fuel consumption, emissions species, and soot opacity will record in the study
Characteristics and outcomes of COVID-19 patients admitted to hospital with and without respiratory symptoms
Background: COVID-19 is primarily known as a respiratory illness; however, many patients present to hospital without respiratory symptoms. The association between non-respiratory presentations of COVID-19 and outcomes remains unclear. We investigated risk factors and clinical outcomes in patients with no respiratory symptoms (NRS) and respiratory symptoms (RS) at hospital admission. Methods: This study describes clinical features, physiological parameters, and outcomes of hospitalised COVID-19 patients, stratified by the presence or absence of respiratory symptoms at hospital admission. RS patients had one or more of: cough, shortness of breath, sore throat, runny nose or wheezing; while NRS patients did not. Results: Of 178,640 patients in the study, 86.4 % presented with RS, while 13.6 % had NRS. NRS patients were older (median age: NRS: 74 vs RS: 65) and less likely to be admitted to the ICU (NRS: 36.7 % vs RS: 37.5 %). NRS patients had a higher crude in-hospital case-fatality ratio (NRS 41.1 % vs. RS 32.0 %), but a lower risk of death after adjusting for confounders (HR 0.88 [0.83-0.93]). Conclusion: Approximately one in seven COVID-19 patients presented at hospital admission without respiratory symptoms. These patients were older, had lower ICU admission rates, and had a lower risk of in-hospital mortality after adjusting for confounders