scholarly journals Operation Analysis of Selected Domestic Appliances Supplied with Mixture of Nitrogen-Rich Natural Gas with Hydrogen

2021 ◽  
Vol 13 (24) ◽  
pp. 13577
Author(s):  
Robert Wojtowicz ◽  
Jacek Jaworski
Keyword(s):  
Natural Gas ◽  
Thermal Efficiency ◽  
Heat Input ◽  
Hot Water ◽  
Test Results ◽  
Hydrogen Addition ◽  
Energy Parameters ◽  
Operation Analysis ◽  
Proper Operation ◽  
Domestic Appliances

This article presents the results of the testing of the addition of a hydrogen-to-nitrogen-rich natural gas of the Lw group and its influence on the operation of selected gas-fired domestic appliances. The tests were performed on appliances used for the preparation of meals and hot water production for hygienic and heating purposes. The characteristics of the tested gas appliances are also presented. The burners and their controllers, with which the tested appliances were equipped, were adapted for the combustion of Lw natural gas. The tested appliances reflected the most popular designs for domestic gas appliances in their group, used both in Poland and in other European countries. The tested appliances were supplied with nitrogen-rich natural gas of the Lw group, and a mixture of this gas with hydrogen at 13.2% content. The article presents the approximate percentage compositions of the gases used during the tests and their energy parameters. The research was focused on checking the following operating parameters and the safety of the tested appliances: the rated heat input, thermal efficiency, combustion quality, ignition, flame stability, and transfer. The article contains an analysis of the test results, referring, in detail, to the issue of decreasing the heat input of the appliances by lowering the energy parameters of the nitrogen-rich natural gas of the Lw group mixture with a hydrogen addition, and how it influenced the thermal efficiency achieved by the appliances. The conclusions contain an explanation regarding, among other things, how the design of an appliance influences the thermal efficiency achieved by it in relation to the heat input decrease. In the conclusions, on the basis of the research results, answers have been provided to the following questions: (1) Whether the hydrogen addition to the nitrogen-rich natural gas of the Lw group will influence the safe and proper operation of domestic gas appliances; (2) What hydrogen percentage can be added to the nitrogen-rich natural gas of the Lw group in order for the appliances adapted for combusting it to operate safely and effectively, without the need for modifying them?

Theoretical Analyses of Heat Balance in a Diesel/Natural Gas Dual-Fuel Engine at Low and Medium Loads Based on Experimental Values

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Zhongshu Wang ◽  
Guizhi Du ◽  
Ming Li ◽  
Yun Xu ◽  
Fangyuan Zhang
Keyword(s):  
Heat Transfer ◽  
Natural Gas ◽  
Thermal Efficiency ◽  
Hot Water ◽  
Energy Utilization ◽  
Dual Fuel ◽  
Exergy Destruction ◽  
Energy Fraction ◽  
Combustion Heat ◽  
Diesel Injection

Abstract In order to propose the control strategies based on exergy to realize efficient and energy-saving operation of the engine, the energy and exergy balance under sensitive boundary conditions were analyzed with the first and second laws of thermodynamics on a six-cylinders, four strokes, turbocharged, intercooled, and high-pressure common rail diesel/natural gas (NG) dual-fuel engine in this paper. The results depicted that the thermal efficiency and exergy efficiency decrease with the increase of NG percentage energy substitution rate (PES). Compared with other conditions, at medium load, 1978 rpm and 90% PES, the exergy destruction caused by irreversibility process including mixing combustion, heat transfer and mechanical friction reaches 72.33%. With the advance of diesel injection time (Tinj), thermal efficiency and energy fraction of heat transfer increase first and then decrease. However, diesel injection pressure (Pinj) has little effect on improving energy utilization. Compared with single diesel injection, appropriate multiple diesel injection can improve combustion performance and energy utilization. When the first Tinj is 35 deg CA BTDC and second Tinj is 25 deg CA BTDC, nearly 50% of the energy lost in heat transfer can be converted into useful work. The lost exergy can be reduced by choosing appreciate Tinj and Pinj, adding exhaust gas recirculation (EGR) to reduce in-cylinder temperature to improve combustion and using thermal insulation materials to reduce heat transfer or using the lost heat in other processes such as preheating intake air and producing the hot water or steam of external consumption to reduce the exergy destruction.

Development of Low NOx Combustion Technology in Medium-Btu Fueled 1300 °C-Class Gas Turbine Combustor in IGCC

2000 ◽  
Author(s):  
Takeharu Hasegawa ◽  
Tohru Hisamatsu ◽  
Yasunari Katsuki ◽  
Mikio Sato ◽  
Hiromi Koizumi ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Nox Emission ◽  
Test Results ◽  
Nitrogen Injection ◽  
Coal Gasifier ◽  
Coal Fuel ◽  
Thermal Nox ◽  
Low Nox Emission

The development of integrated coal gasification combined cycle (IGCC) systems ensures higher thermal efficiency and environmentally sound options for supplying future coal utilizing power generation needs. The Japanese government and electric power industries in Japan promoted research and development of an IGCC system using an air-blown entrained-flow coal gasifier. On the other hand, Europe and the United States are now developing the oxygen-blown IGCC demonstration plants. Gasified coal fuel produced in an oxygen-blown entrained-flow coal gasifier, has a calorific value of 8–13MJ/m3 which is only 1/5–1/3 that of natural gas. However, the flame temperature of medium-Btu gasified coal fuel is higher than that of natural gas and so NOx production from nitrogen fixation is expected to increase significantly. In the oxygen-blown IGCC, a surplus nitrogen produced in the air-separation unit (ASU) is premixed with gasified coal fuel (medium-Btu fuel) and injected into the combustor, to reduce thermal-NOx production and to recover the power used for the ASU. In this case, the power to compress nitrogen increases. Low NOx emission technology which is capable of decreasing the power to compress nitrogen is a significant advance in gas turbine development with an oxygen-blown IGCC system. Analyses confirmed that the thermal efficiency of the plant improved by approximately 0.3 percent (absolute) by means of nitrogen direct injection into the combustor, compared with a case where nitrogen is premixed with gasified coal fuel before injection into the combustor. In this study, based on the fundamental test results using a small diffusion burner and a model combustor, we designed the combustor in which the nitrogen injection nozzles arranged on the burner were combined with the lean combustion technique for low-NOx emission. In this way, we could reduce the high temperature region, where originated the thermal-NOx production, near the burner positively. And then, a combustor with a swirling nitrogen injection function used for a gas turbine, was designed and constructed, and its performance was evaluated under pressurized conditions of actual operations using a simulated gasified coal fuel. From the combustion test results, the thermal-NOx emission decreased under 11ppm (corrected at 16% O2), combustion efficiency was higher than 99.9% at any gas turbine load. Moreover, there was different effects of pressure on thermal-NOx emission in medium-Btu fuel fired combustor from the case of natural gas fired combustor.

scholarly journals Three Steps Mixed (Fire Tube–Water Tube) Vertical Boiler to Optimize Thermal Performance

Fluids ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 93
Author(s):  
Duilio Aguilar Vizcarra ◽  
Doris Esenarro ◽  
Ciro Rodriguez
Keyword(s):  
Natural Gas ◽  
Technological Innovation ◽  
Thermal Efficiency ◽  
Low Temperatures ◽  
Alternative Fuels ◽  
Hot Water ◽  
Water Steam ◽  
Water Tube ◽  
Liquid Petroleum Gas ◽  
Thermal Oil

The research aims to design and construct a new mixed vertical boiler (fire tube – water tube) with three gas passes. The strength of this technological innovation is in the best use of the thermic transmission receiving fluid (hot water, steam, thermal oil), this due to its multipurpose function of three steps using alternative fuels (Diesel, Liquid Petroleum Gas LPG, natural gas), by improving the thermal efficiency of the boiler its temperature is reduced with gases at low temperatures, which in turn also reduce environmental pollution. The methodology focuses on calculating the transfer area with the calculation method that will allow dimensioning the boiler, considering the calculation of losses and the fluid speed, with two defined procedures, the first for fire tube and water tube boilers. And another alternative. The results obtained allowed optimizing the thermal efficiency level, achieving very significant thermal efficiency results: With LPG 92.4% for hot water and 92.42% to generate steam in the same way with natural gas 90.25% for hot water and 90.24% to generate steam as well with Diesel 2; 89.21% for hot water and 89.31% to generate steam.

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