Energy efficiency through industrial excess heat recovery—policy impacts

The main problems connected with an increase in the performance efficiency of the mine power complexes, should include issues of rational use of fuel in power facilities, as well as the maximum consumption of produced thermal and electrical energy. One solution to this problem has been proposed to use in schematic solutions the reaction-type hydro-steam turbine for excess heat recovery of and generation of additional electrical energy. The condition has been set in the article for the choice of the configuration of a hydro-steam turbine nozzle with a high efficiency of energy conversion, as well as the variants have been studied of principle schemes for energy complexes: the scheme for a power facility, consisting of a gas-reciprocating module, on the shaft of which a module with a hydro-steam turbine is set, as well as the scheme for a module placement of back pressure turbine and hydro-steam turbine on the same shaft with a gas-reciprocating module. A comparative analysis has been performed of energy efficiency of the proposed principle schemes for the energy complexes.

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Energy and Exergy Analyses of Tube Banks in Waste Heat Recovery Applications

Energies ◽

10.3390/en11082094 ◽

2018 ◽

Vol 11 (8) ◽

pp. 2094 ◽

Cited By ~ 7

Author(s):

Mustafa Erguvan ◽

David MacPhee

Keyword(s):

Energy Efficiency ◽

Reynolds Number ◽

Heat Recovery ◽

Waste Heat ◽

Cross Flow ◽

Exergy Efficiency ◽

Circular Cylinders ◽

Published Data ◽

Energy And Exergy ◽

Exergy Analyses

In this study, energy and exergy analyses have been investigated numerically for unsteady cross-flow over heated circular cylinders. Numerous simulations were conducted varying the number of inline tubes, inlet velocity, dimensionless pitch ratios and Reynolds number. Heat leakage into the domain is modeled as a source term. Numerical results compare favorably to published data in terms of Nusselt number and pressure drop. It was found that the energy efficiency varies between 72% and 98% for all cases, and viscous dissipation has a very low effect on the energy efficiency for low Reynolds number cases. The exergy efficiency ranges from 40–64%, and the entropy generation due to heat transfer was found to have a significant effect on exergy efficiency. The results suggest that exergy efficiency can be maximized by choosing specific pitch ratios for various Reynolds numbers. The results could be useful in designing more efficient heat recovery systems, especially for low temperature applications.

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ОСОБЕННОСТИ ПРИМЕНЕНИЯ ПРОДУКТОВ КОНВЕРСИИ МЕТАНОЛА В СУДОВОЙ ГАЗОТУРБИННОЙ УСТАНОВКЕ С ТЕРМОХИМИЧЕСКОЙ РЕГЕНЕРАЦИЕЙ СБРОСНОГО ТЕПЛА

Aerospace technic and technology ◽

10.32620/aktt.2019.3.03 ◽

2019 ◽

pp. 28-34 ◽

Cited By ~ 1

Author(s):

Александр Константинович Чередниченко

Keyword(s):

Energy Efficiency ◽

Gas Turbine ◽

Heat Recovery ◽

Power Plants ◽

Low Carbon ◽

Steam Conversion ◽

Working Pressure ◽

Fixed Temperature ◽

Heat Potential ◽

Thermochemical Heat Recovery

The research’s subject is the processes of energy transformation of fuel in the ship gas turbine plant with thermochemical regeneration. Modern approaches to assessing the energy efficiency of ship power plants were considered. The characteristics of traditional and alternative marine fuels were analyzed. The use of methanol as a low-carbon marine fuel is discussed. It is proposed to increase the efficiency of methanol use by using synthesis gas obtained through thermochemical heat recovery of secondary energy resources of ship engines. The main objective of the study is to analyze the effects on the energy efficiency of steam thermochemical transformation of methanol of the limitations associated with the system of supplying gaseous fuel to the engine. The influence of pressure in the thermochemical reactor on the steam’s efficiency of reforming of methanol was analyzed. The design schemes of two variants of the ship gas turbine installation with thermochemical heat recovery by steam conversion of methanol are presented. The methanol conversion efficiency was determined by the heat potential of the exhaust gases and was calculated based on the thermal balance of the thermochemical reactor. The reactor’s model is two- component. The mathematical model of the turbocompressor unit is based on an enlarged calculation taking into account the total pressure loss in all elements of the gas-air duct. The results of mathematical modeling of processes in plants based on gas turbine engines of simple and regenerative cycles under conditions of fixed methanol’s consumption, the fixed temperature of the gas in the turbine’s front for environmental parameters according to ISO 19859: 2016 are presented. The efficiency of the scheme which used steam conversion of methanol at pressures corresponding to the working pressure in the combustion chamber was revealed. The increase in the energy efficiency of the installation is 3 ... 5 % with basic parameters and 10 ... 11 % for higher conduction temperatures or for catalytic reactors. The research results can be used in the promising power plants designing.

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