On the possible increasing of efficiency of ship power plant with the system combined of marine diesel engine, gas turbine and steam turbine in case of main engine cooperation with the gas turbine fed in parallel and the steam turbine

Abstract

The article presents a concept of a combined large-power ship propulsion system, composed of the leading internal combustion main engine associated with a power gas turbine and the steam turbine system, both utilising the energy taken from the main engine exhaust gas. In the examined variant the power turbine, arranged in parallel with a turbocharger, is fed with the exhaust gas from the exhaust manifold. A calculation algorithm is presented, along with sample calculations for particular subsystems: supercharging, gas power turbine, and steam turbine system. Assumptions were formulated for the calculations, and were complemented by the adopted limits. Selected system parameters were confronted with the experimental investigations available in the literature. The performed power optimisation of the entire combined marine power plant took only into account the thermodynamic point of view, leaving aside technical and economic aspects. The numerical calculations were performed for the 52 MW low-speed marine diesel engine.

Analysis of Possible Application of High-Temperature Nuclear Reactors to Contemporary Large-Output Steam Power Plants on Ships

“…Engines of the type, i.e. internal-combustion ones, are characterized by a high efficiency of the order of 51% [3,11,12]. Their huge popularity in shipbuilding results from economic conditions, namely, relatively low investment cost , low specific fuel combustion, possible charging with cheap heavy fuel oil.…”

“…Piston engines have also some disadvantages such as large mass of power plant , generation of nuisance vibration , long start-up period as well as emission of gas black and sulphur oxides in case of heavy oil charging. Aspects of emission of noxious substances negatively influence profitability of low-speed engines as regulations limiting exhaust gas emission level become more and more restrictive [3,11,12,14].…”

“…Turbine engines are characteristic of a high ratio of power output to mass of power plant, generation of high frequency vibrations (in contrast to piston engines, there occur no nuisance vibration but high frequency noise difficult to be damped) [3,11]. Additionally , gas turbines can be very fast started hence ship can reach full serviceability much faster [2,11] , as well as no "running-in" period is necessary [9].…”

“…The aims can be reached by applying balanced energy conversion which becomes more and more popular both in the case of conventional fuels and alternative ones [2]. As far as sea transport has been concerned this means perfecting the combustion engine power plants and combined systems [3,11,12], improving operational parameters of gas turbines [13] and steam thermal cycles [8], developing novel systems based on fuel cells -SOFC [14] as well as making use of nuclear energy [15]. Special attention should be paid to HTR nuclear reactors.…”

On the possible increasing of efficiency of ship power plant with the system combined of marine Diesel engine, gas turbine and steam turbine in case of main engine cooperation with the gas turbine fed in series and the steam turbine

“…The analysed combined power plant consists of a Diesel engine 9RTA-96C, identical to that discussed in [2,3], the power turbine, fed in series, and the steam system with a steam turbine. Additional power of the propulsion system, obtained both from the power turbine and the steam turbine, is transmitted to the ship propeller shaft via a mechanical gear.…”