10.Gas Turbines(Outlook on Internal Combustion Engines)

1952 ◽  
Vol 55 (398) ◽  
pp. 202-203
Author(s):  
Kin-ichi NAKATA
Keyword(s):  
Gas Turbines ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Combustion Engines

A Table of Thermodynamic Properties of Air

1943 ◽  
Vol 10 (3) ◽  
pp. A123-A130
Author(s):  
Joseph H. Keenan ◽  
Joseph Kaye
Keyword(s):  
Thermodynamic Properties ◽  
Gas Turbines ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Linear Interpolation ◽  
Combustion Engines ◽  
Dry Air ◽  
Single Argument ◽  
Air Compressors

Abstract Over the range of conditions for which the equation pv = RT represents satisfactorily the p-v-T relation, a table having a single argument, the temperature, serves all the purposes which are served by vapor tables (steam tables, ammonia tables, etc.) having two arguments. A table of this sort with intervals small enough for linear interpolation is presented for dry air. Data from this table are compared with corresponding values from the tables of Sage and Lacey. The use of the table is illustrated with examples of the calculation of processes involved in air compressors, nozzles, internal-combustion engines, and gas turbines.

scholarly journals Analysing the Performance of Ammonia Powertrains in the Marine Environment

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7447
Author(s):  
Thomas Buckley Imhoff ◽  
Savvas Gkantonas ◽  
Epaminondas Mastorakos
Keyword(s):  
Marine Environment ◽  
Gas Turbines ◽  
Internal Combustion Engines ◽  
Chemical Engineering ◽  
Feasibility Studies ◽  
Internal Combustion ◽  
Alternative Fuel ◽  
System Level ◽  
Combustion Engines ◽  
Catalytic Material

This study develops system-level models of ammonia-fuelled powertrains that reflect the characteristics of four oceangoing vessels to evaluate the efficacy of ammonia as an alternative fuel in the marine environment. Relying on thermodynamics, heat transfer, and chemical engineering, the models adequately capture the behaviour of internal combustion engines, gas turbines, fuel processing equipment, and exhaust aftertreatment components. The performance of each vessel is evaluated by comparing its maximum range and cargo capacity to a conventional vessel. Results indicate that per unit output power, ammonia-fuelled internal combustion engines are more efficient, require less catalytic material, and have lower auxiliary power requirements than ammonia gas turbines. Most merchant vessels are strong candidates for ammonia fuelling if the operators can overcome capacity losses between 4% and 9%, assuming that the updated vessels retain the same range as a conventional vessel. The study also establishes that naval vessels are less likely to adopt ammonia powertrains without significant redesigns. Ammonia as an alternative fuel in the marine sector is a compelling option if the detailed component design continues to show that the concept is practically feasible. The present data and models can help in such feasibility studies for a range of vessels and propulsion technologies.

STORING RENEWABLE ENERGIES IN A SUBSTITUTE OF NATURAL GAS

2019 ◽  
pp. 67-75
Author(s):  
G. Spazzafumo
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
Electric Power ◽  
Gas Turbines ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Inlet Temperature ◽  
Combustion Engines ◽  
Waste Products ◽  
Electrolytic Hydrogen

This paper proposes a way to obtain valuable electric power and valuable fuel starting from renewable variable electric power plus biomass and/or waste products. Biomass/biofuel can be oxyburned using electrolytic oxygen to generate electric power. Gas turbines or internal combustion engines are suitable to such a task, but there is the problem of very high temperatures connected to oxy combustion. In the case of gas turbine the inlet temperature could be controlled by adding steam and/or carbon dioxide, while in the case of internal combustion engines only carbon dioxide could be used. In such a way the exhaust gas continues to be formed by carbon dioxide and steam which can be easily separated by condensation. Carbon dioxide is fed to a Sabatier process together with electrolytic hydrogen to generate a gas with characteristics similar to natural gas. Although electrolytic hydrogen could be used directly both in internal combustion engines and fuel cells, significant problems to hydrogen distribution and on-board storing still exists. Therefore the substitute of natural gas could be a real bridge solution for the short/medium term. A  simulation has been carried out and the resulting efficiencies range from 0.52 to 0.58.

Energetic and Exergetic Analysis of Building Cogeneration Systems

2008 ◽  
Author(s):  
Yilmaz Yoru ◽  
T. Hikmet Karakoc ◽  
Arif Hepbasli ◽  
Enis T. Turgut
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Gas Turbines ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
System Capacity ◽  
Combustion Engines ◽  
Exergetic Analysis ◽  
External Combustion ◽  
Thermophotovoltaic Systems

This study deals with types of micro cogeneration (or micro combined heat and power, MCHP) systems and reviews energetic and exergetic analysis of MCHP systems, which are also called building cogeneration systems. These are classified as micro and macro cogeneration systems and figured within subgroups. Previously conducted studies on exergy and energy analyses of internal combustion engines (micro turbines), external combustion engines (Ericsson engines), fuel cells (solid oxide fuel cells) and thermophotovoltaic systems are treated in this paper. The main objectives of this study are to classify MCHP systems used in building cogeneration systems, to introduce types of MCHP systems and to better define micro cogeneration systems in the light of previously conducted studies. In this regard, energetic and exergetic efficiencies of various MCHP systems are graphically obtained. Under grouping presented MCHP systems, internal combustion engines based MCHP systems are defined to be the best choice with energetic and exergetic efficiency values of 86.0% and 40.31%, respectively. Micro gas turbines and Ericson engine based micro cogeneration systems are also obtained as valuable systems with the energetic values of 75.99% and 65.97% and exergetic values of 35.8% and 38.5%, respectively. However, in this building cogeneration group, energetic and exergetic efficiencies of the thermophotovoltaic systems have 65.0% and 15.0%, respectively. It may be concluded that system choice depends on the type of the system, energy flow of the system, system parts and developments, while building, system capacity, comfort and maintenance are the other factors to be considered.

scholarly journals Overview of the Green Hydrogen Applications in Marine Power Plants Onboard Ships

2018 ◽  
Vol 6 (01) ◽  
Author(s):  
Nader R. Ammar ◽  
Nayef F. S. H. Alshammari
Keyword(s):  
Fuel Cells ◽  
Gas Turbines ◽  
Power Plants ◽  
Internal Combustion Engines ◽  
Fossil Fuels ◽  
Clean Energy ◽  
Internal Combustion ◽  
Green Energy ◽  
Hydrogen Gas ◽  
Combustion Engines

The need for renewable and green energy sources to replace fossil fuel with the incrementally rising prices is driving many researchers to work on narrowing the gap between the most scientific innovative clean energy technologies and the concepts of feasibility and cost-effective solutions. The current paper aims to introduce one aspect of Green Energy; the use of Hydrogen as fuel for marine power plants, to replace all kinds of fossil fuels which are the major responsible of harmful emissions. There are three applications for hydrogen in marine field. These applications include hydrogen internal combustion engines, hydrogen gas turbines, and fuel cells. The main problems associated with the application of hydrogen in internal combustion engines are the engine knocking; air fuel ratio and intake temperature. The research programs for the application of hydrogen in gas turbines concentrate on studying the characteristics of hydrogen combustion inside gas turbine combustors. The third application of hydrogen is fuel cells. Huge developments have been achieved in this sector over the past few years. But for the marine field only the naval vessels market used it for auxiliary power generation.

Second Law of Thermodynamics for Changes of State and Quantity of Working Substance With Particular Reference to Steam Engines

1944 ◽  
Vol 11 (2) ◽  
pp. A108-A112
Author(s):  
G. Zerkowitz
Keyword(s):  
Gas Turbines ◽  
Internal Combustion Engines ◽  
Second Law Of Thermodynamics ◽  
Internal Combustion ◽  
Second Law ◽  
Thermal Processes ◽  
Combustion Engines ◽  
First Law Of Thermodynamics ◽  
Change Of State ◽  
Changes Of State

Abstract For many years the author had devoted increased attention and study to the problems of the change of state and quantity of thermal working substances. These thermal processes particularly occur in piston engines, e.g., in steam engines during admission and release, in internal-combustion engines in the exhaust, and in compressors during the inlet to and the outlet from the cylinder. In turboengines they also can play a part, e.g., in gas turbines with explosion chambers, such as the Holtzwarth turbine. In the author’s former essay numerous instances based on the first law of thermodynamics have been dealt with whereas, in this paper, first some other applications of the first law of thermodynamics and then the formulation of the second law of thermodynamics for changes of state and quantity will be presented. Particular attention will be devoted to the thermodynamic aspect of the entropy diagrams dealing with variable quantities, and the sources of errors which may occur when using such diagrams.

Proposal Design Procedure and Preliminary Simulation of Turbo Expander for Small Size (2–10 kW) Organic Rankine Cycle (ORC)

2014 ◽  
Author(s):  
Roberto Capata ◽  
Gustavo Hernandez
Keyword(s):  
Gas Turbines ◽  
Internal Combustion Engines ◽  
Design Procedure ◽  
Rankine Cycle ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Large Power ◽  
Exhaust Gases ◽  
Turbo Expander ◽  
Organic Fluids

Currently, one of the leading technologies for the “energy recovery” adopting a Rankine cycle (ORC) with organic fluids. ORC system operates like a conventional Rankine cycle, but instead of steam/water, uses an organic fluid. This change allows to convert low temperature heat and generate, where required, electricity. A large amount of studies were carried out to identify the most suitable fluids, system parameters and the various configurations. In reality, most ORC systems are designed and manufactured for recovery of thermal energy from various sources but at “large power rating” (exhaust gas turbines, internal combustion engines, geothermal sources, large melting furnaces, biomass, solar, etc.) from where it is possible to produce electric energy (30kW ÷ 300kW), but for the application of this system for small nominal power, as well as the exhaust gases of internal combustion engines (car sedan or town, ships, etc.) or smaller heat exchangers, there are very few applications. The aim of this work is to design a turbo-expander that meets system requirements: low pressure, small size, low mass flow rates. The Expander must be adaptable to a small ORC system utilizing gas of a diesel engine or small gas turbine to produce 2–10 kW of electricity. The temperature and pressure of the exhaust gases, in this case study (400–600° C and at a pressure of 2 bar), imposes a limit on the use of an organic fluid and on the net power that can be produced. In addition to water, organic fluids such as CO2, R134a and R245fa have been considered. Once the fluid has been chosen operating, the turbine characteristics (dimensions, temperature, input and output pressure ratio, etc.) have been calculated and an attempt to find the “nearly-optimal” has been carried out. The detailed design of radial Expander is presented and discussed. An initial thermo-mechanical performance study is carried out to verify structural tension and possible displacement. Next step of the research here proposed will be the CFD simulation to improve or modify the chosen blade profile.

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