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

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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A Comparative Study of the Performance of a SI Engine Fuelled by Natural Gas as Alternative Fuel by Thermodynamic Simulation

ASME 2009 Internal Combustion Engine Division Fall Technical Conference ◽

10.1115/icef2009-14017 ◽

2009 ◽

Cited By ~ 2

Author(s):

Mehrnoosh Dashti ◽

Ali Asghar Hamidi ◽

Ali Asghar Mozafari

Keyword(s):

Experimental Data ◽

Natural Gas ◽

Thermal Efficiency ◽

Alternative Fuels ◽

Thermodynamic Simulation ◽

Internal Combustion ◽

Alternative Fuel ◽

Spark Ignition Engine ◽

Solution Temperature ◽

Si Engine

With the declining energy resources and increase of pollutant emissions, a great deal of efforts has been focused on the development of alternatives for fossil fuels. One of the promising alternative fuels to gasoline in the internal combustion engine is natural gas [1–5]. The application of natural gas in current internal combustion engines is realistic due to its many benefits. The higher thermal efficiency due to the higher octane value and lower exhaust emissions including CO2 as a result of the lower carbon to hydrogen ratio of the fuel are the two important feature of using CNG as an alternative fuel. It is well known that computer simulation codes are valuable economically as a cost effective tool for design and analysis of the engine operations. In the present work the use of an exiting spark ignition engine to run on both gasoline and CNG is evaluated by thermodynamic simulation of the engine cycle. The stepwise calculations for pressure and temperature of the cylinder at compression process, ignition delay time, combustion and expansion processes have been considered. The first law of thermodynamics is applied for all steps and Newton-Raphson method is used for the numerical solution. Temperature dependent specific heat capacity and as a result specific enthalpy, entropy, internal energy and specific Gibbs functions are calculated in each step. Two zones model for the combustion process simulation has been used and the mass burning rate is predicted by considering the propagation of the flame front spherically. The performance characteristics including power, IMEP, ISFC, thermal efficiency and emissions concentration of SI engine on both gasoline and CNG fuel are determined by the model. In order to validate the model, the results are compared with the corresponding experimental data. It is found that the simulated results show reasonable agreement with the experimental data.

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Natural Gas Saving And Emissions Decrease In Public Health Care Sector – A Case Study

Civil and Environmental Engineering Reports ◽

10.2478/ceer-2019-0008 ◽

2019 ◽

Vol 29 (1) ◽

pp. 102-118

Author(s):

Otto Mierka ◽

Miroslav Variny ◽

Ingrida Skalíková ◽

Peter Sámel ◽

Ján Kizek ◽

...

Keyword(s):

Public Health ◽

Health Care ◽

Natural Gas ◽

Health Care Sector ◽

Hot Water ◽

Public Health Care ◽

Blow Down ◽

Water Steam ◽

Gas Consumption ◽

Natural Gas Consumption

Abstract A study on natural gas saving and emissions decrease in the public health care sector is presented. The analyzed hospital complex belongs to the largest ones in Slovakia and uses both hot water and water steam for heating purposes. Visual steam system inspection revealed serious inefficiencies, including steam venting, missing pipelines insulation and obsolete steam sources with dysfunctional blow-down system. Defined experiment with stepwise steam appliances shutdown enabled quantification of excess natural gas consumption due to these inefficiencies. Measures proposed for the solution of this state are inexpensive, with a short payback period. The expected natural gas savings amount up to 3200 MWh/year, which represents roughly 50% of the total natural gas consumption in the hospital complex.

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

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4046760 ◽

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.

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Low Emission LNG Fuelled Ships for Environmental Friendly Operations in Arctic Areas

Volume 6: Polar and Arctic Sciences and Technology; Offshore Geotechnics; Petroleum Technology Symposium ◽

10.1115/omae2013-11644 ◽

2013 ◽

Cited By ~ 1

Author(s):

Vilmar Æsøy ◽

Dag Stenersen

Keyword(s):

Natural Gas ◽

Thermal Efficiency ◽

Distribution System ◽

Heat Recovery ◽

Alternative Fuels ◽

Waste Heat ◽

Global Perspective ◽

Emission Reductions ◽

Promising Alternative ◽

Exhaust Heat

Environmental restrictions now favor cleaner fuels, and Natural gas (LNG) is one of the most promising alternative fuels. Highly efficient natural gas fuelled engines have been developed since around 1990. These engines are now entering maritime applications, offering significant emission reductions, both in a local and global perspective. Using LNG as fuel reduce NOx emissions by up to 90%, SOx and particulate matter (soot) are reduced by 95–100% and CO2 emissions are reduced by up to 25%, when compared to traditional marine fuels. These emission reductions are significant contribution especially in local and regional environments. Using LNG as a clean fuel also offers a significant increase in total energy efficiency. Combining power and heat generation, natural gas fuelled engines for on-shore power generation offer a total thermal efficiency of 80–90%, depending on the waste heat recovery rate. For liquid fuels exhaust heat recovery is limited due to the sulfur content, which may cause acid corrosion. Onboard ships, LNG fuelled engines have potential to utilize waste heat to obtain significant higher thermal efficiency than their diesel engine counterpart. LNG is mainly available from fossil sources, but now also increasingly from renewable sources as bio-gas. For storing and transportation LNG is preferred as less challenging compared to high pressure CNG. On the coast of Norway a LNG distribution system is now being built, supplying a fleet of more than 40 ships. LNG is transported by special designed small LNG carriers from the production plants to a series of main terminals along the coastline. From these main terminals the LNG is distributed by trucks to the local fuelling stations, or for direct fuelling of the ships. This paper will present the basic technology and experiences from this full scale LNG fuel system. The paper will discuss local and global environmental benefits, technical solutions, safety issues, and costs issues related to the distribution system and the on-board fuel installations.

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

Sustainability ◽

10.3390/su132413577 ◽

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?

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Split Estate and Wyoming’s Orphaned Well Crisis: The Case of Coalbed Methane Reclamation in the Powder River Basin, Wyoming

Case Studies in the Environment ◽

10.1525/cse.2017.000455 ◽

2017 ◽

Vol 1 (1) ◽

pp. 1-8 ◽

Cited By ~ 3

Author(s):

Kathryn Bills Walsh

Keyword(s):

Natural Gas ◽

River Basin ◽

Technological Innovation ◽

Coalbed Methane ◽

Powder River Basin ◽

Gas Wells ◽

Mineral Rights ◽

Split Estate ◽

Legal Condition

This case presents the stakeholder conflicts that emerge during the development and subsequent reclamation of abandoned natural gas wells in Wyoming where split estate, or the separation of surface land and mineral rights from one another, occurs. From 1998 to 2008, the Powder River Basin of northeastern Wyoming experienced an energy boom as a result of technological innovation that enabled the extraction of coalbed methane (CBM). The boom resulted in over 16,000 wells being drilled in this 20,000 square-mile region in a single decade. As of May 2017, 4,149 natural gas wells now sit orphaned in Wyoming as a result of industry bankruptcy and abandonment. The current orphaned wells crisis was partially enabled by the patchwork of surface and mineral ownership in Wyoming that is a result of a legal condition referred to as split estate. As the CBM boom unfolded in this landscape and then began to wane, challenges emerged most notably surrounding stalled reclamation activities. This case illuminates these challenges highlighting two instances when split estate contributed to issues between landowners and industry operators which escalated to litigation.

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