Isobaric and Isochoric Heat Capacities of Imidazolium-Based and Pyrrolidinium-Based Ionic Liquids as Function of Temperature: Modeling of Isobaric Heat Capacity

International audienceThe isobaric and isochoric heat capacities of seven 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imides, two 1-alkyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imides, and two bis(1-alkyl-3-methylimidazolium) tetrathiocyanatocobaltates were determined at atmospheric pressure in the temperature range from 293.15 to 323.15 K. The isobaric heat capacities were determined by means of differential scanning calorimetry, whereas isochoric heat capacities were determined along with isothermal compressibilities indirectly by means of the acoustic method from the speed of sound and density measurements. Based on the experimental data, as expected, the isobaric heat capacity increases linearly with increasing alkyl chain length in the cation of 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imides and no odd and even carbon number effect is observed. After critical comparison of the obtained data with the available literature data, the most reliable values are recommended. It has been also shown that, although the COSMOthermX calculations underestimated the isobaric heat capacity values whatever the temperature and the ionic liquid structure, the approach used during this work may be applied to estimate physical properties of non-single-charged ions as well. Additionally, based on the speeds of sound the thermal conductivities were calculated using a modified Bridgman relation

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 article presents a concept of a combined large power ship propulsion system consisting of the leading Diesel main engine, associated with a power gas turbine and the steam turbine system which utilise the energy contained in the exhaust gas leaving the Diesel engine. In the examined variant of the combined system the power turbine is fed in series with the exhaust gas. A calculation algorithm is given along with the results of calculations of particular subsystems of: the turbocharging system, the power gas turbine, and the steam turbine cycle. Assumptions and limits adopted in the calculations are presented. Selected system parameters were confronted with the results of experimental investigations available in the literature. The power optimisation of the entire combined ship power plant was only performed taking into account the thermodynamic point of view, leaving aside technical and economic aspects. Numerical calculations were performed for the 52 MW low-speed Diesel engine produced by Wärtsilä

Laboratory stand of rotor compressor

Przedstawiono stoisko badawczo-dydaktyczne sprężarki wirnikowej do badań charakterystyk statycznych i dynamicznych. Ponadto założenia projektowe oraz opis stanowiska. Dołaczono przykłady pomiarów charakterystyk statycznych i dynamicznych sprężarki wirnikowej.The paper presents an educational laboratory stand of rotor compressor. The stand enables investigations of ateady-state as well as dynamic characteristics of radial rotor compressor

Small wood waste fired combined heat and power plant. Possible use of wood biomass for the generation of electric and heat energy as an alternative to fossil fuels

This article discusses the possibility of burning wood biomass instead of fossil fuels in boilers. It describes the properties of wood biomass, including the variation of its calorific value depending on the moisture content of wood. The article proposes several variants of a combined heat and power plant (CHP) system burning wood biomass for the generation of electric and heat energy, using the energy contained in exhaust gases for drying wood biomass

Thermodynamic properties of isomeric pentanols under elevated pressures determined by the acoustic method

Three isomeric pentanols were studied: pentan-1-ol, 2-methyl-1-buta- nol, and 2-methyl-2-butanol. Isobaric heat capacities and internal pressure at pressures up to 100 MPa and temperatures ranging from 293 K to 318 K were determined by the acoustic method. In calculations the measured speeds of sound as function of temperature and pressure together with densities as function of temperature under atmospheric pressure and the literature isobaric heat capacities for the atmospheric pressure were used. To this end, the method, based on the suggestion of Davis and Gordon [1] was applied. The results obtained show that the effect of pressure on and the values of isobaric heat capacity and internal presure of 2-methyl-2-butanol is higher than that of pentan-1-ol, 2-methyl-1-butanol over the whole pressure range. That facilitates telling 2-methyl-2-butanol from pentan-1-ol and 2-methyl-1-butanol

Influence of gas turbine controller adjustment on ship propulsion system behavior in rough sea conditions. Part 2. The simulation investigations

The paper presents simulation investigations of influence of gas turbine controller adjuŹstment on ship propulsion system operating in heavy sea conditions, based on the model presented in Part 1 of the paper. The ship propulsion system with two gas turbines driŹving - through mechanical gear - ship controllable pitch propeller, described in Part 1, was used to analysis. The harmonic disturbances due to sea waves with selected frequencies were used as input function in computing the system’s amplitude characteristics at different settings of P and PD controllers

On the possible increasing of efficiency of ship power plant with the system combined of marine diesel engine, gas turbine and steam turbine, at the main engine - steam turbine mode of cooperation

This paper presents a concept of a ship combined high-power system consisted of main piston engine and associated with it: gas power turbine and steam turbine subsystems, which make use of energy contained in exhaust gas from main piston engine. The combined system consisted of a piston combustion engine and an associated with it steam turbine subsystem, was considered. An algorithm and results of calculations of the particular subsystems, i.e. of piston combustion engine and steam turbine, are presented. Assumptions and limitations taken for calculations, as well as comparison of values of some parameters of the system and results of experimental investigations available from the literature sources, are also given. The system’s energy optimization was performed from the thermodynamic point of view only. Any technical – economical analyses were not carried out. Numerical calculations were performed for a Wärtsilä slow-speed diesel engine of 52 MW output power