Organic Working Fluid Optimization for Space Power Cycles

Angelino, G.; Invernizzi, Costante Mario; Macchi, Ennio

doi:10.1007/978-1-4612-0945-4_16

Cited by 24 publications

(31 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Thermogravimetric analyses within vacuum [23][24][25][26] as well as the analysis of different catalysts [27] are also widespread. A test rig designed especially for measurements of ORC working fluids, and in particular of methylbenzenes, is reported by Angelino et al [28]. Calderazzi and Colonna [29] use a similar test rig for different refrigerants.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Thermal Stability of Hexamethyldisiloxane (MM) for High-Temperature Organic Rankine Cycle (ORC)

Preißinger

Brüggemann

2016

Energies

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

“…In the present study, a redesign of test rig of Angelino et al [28] has been done using an electrical heated tube, which allows for high and accurately controlled heating rates. The main objective is to gain more knowledge on the influence of the working fluid temperature as well as the duration of the experiment.…”

Section: Introductionmentioning

confidence: 99%

Thermal Stability of Hexamethyldisiloxane (MM) for High-Temperature Organic Rankine Cycle (ORC)

Preißinger

Brüggemann

2016

Energies

View full text Add to dashboard Cite

“…In order to better illustrate how x is defined, an exemplary application of this design method is first introduced, namely the preliminary design of a mORC unit (power capacity < 20 kW) for the conversion of medium-temperature thermal sources (maximum cycle temperature < 240 C), and adopting a single-stage radial inflow turbine. This design problem, representative of applications like waste heat recovery from long-haul truck diesel engines [2], or solar power conversion in space [18,19], is particularly challenging because the choice of system operating conditions, working fluid, and components design, are mutually constrained [16]. Fig.…”

Section: Methodsmentioning

confidence: 99%

“…14 displays the corresponding thermodynamic cycles in the temperature-entropy diagram of the working fluid associated with the optimal turbine designs. The difference in the cycle thermal efficiency is mostly determined by the values of the critical temperature and molecular complexity of the working fluid [18]. In this case, all design options might be feasible.…”

Section: Application Of the Surrogate Model: A Test Casementioning

confidence: 99%

Active subspaces for the optimal meanline design of unconventional turbomachinery

Bahamonde

Pini

Servi

et al. 2017

Applied Thermal Engineering

View full text Add to dashboard Cite

h i g h l i g h t sA reduced-order model is proposed for the design of unconventional turbomachinery. The surrogate combines fluid selection, cycle configuration, and turbine geometry. The surrogate outperforms the standard model with negligible computational cost. The new response surface reveals the dominant inputs for turbine performance. The preliminary fluid dynamic design of turbomachinery operating with non-standard working fluids and unusual operating conditions and specifications can be very challenging because of the lack of know-how and guidelines. Examples are the design of turbomachinery for small-capacity organic Rankine cycle and supercritical CO 2 cycle power plants, whereby the efficiency of turbomachinery components has also a strong influence on the net conversion efficiency of the system. These machines operate with the fluid in thermodynamic states which, for part of the process, largely deviate from those obeying to the ideal gas law. This in turn implies the presence of so-called non-ideal compressible fluid dynamics effects. a r t i c l e i n f oActive subspaces, a model reduction technique, is at the basis of the methodology presented here, which is aimed at the optimal meanline design of unconventional turbomachinery. The resulting surrogate model depends on a very small set of non-physical variables, called active variables. The procedure integrates into a single constrained optimization framework the selection of the working fluid, the thermodynamic cycle calculation and the preliminary sizing of the turbomachinery component.As a demonstration of the advantages of the proposed approach, the design of a 10 kW mini organic Rankine cycle turbine with a turbine inlet temperature of 240 C is illustrated. In this case, approximately the same maximum efficiency is estimated for three dissimilar turbines operating with different working fluids and rather different thermodynamic cycles. The use of active subspaces allows the seamless evaluation of the sensitivity of results to input parameters, both those related to the machine and the working fluid. The novel design procedure is compared in terms of computational efficiency to a conventional approach based on the coupling of a genetic algorithm directly with a meanline code. Results show that the calculation based on the use of surrogate models is more than two orders of magnitude faster. The surrogate can be used to solve any design problem within the specified boundaries of the design envelope. Results are affected by uncertainty on the estimation of losses and of non-ideal compressible fluid dynamics effects, which, in turn, do not affect the applicability of the method, which will become quantitatively accurate once this information will be available. Work to this end is underway in various laboratories.

show abstract

“…However, such leaps can increase the investment costs of TGU tremendously when constructional parameters reach specific values. For TGU in ORC systems, the turning point between one-stage turbines and two-stage turbines is between a volume flow ratio of 50 and 220 [92][93][94][95][96]. In this study, we increase the investment costs of the TGU by 25% if the value exceeds a conservative mean value of 100.…”

Section: Turbinementioning

confidence: 99%

Thermoeconomic Evaluation of Modular Organic Rankine Cycles for Waste Heat Recovery over a Broad Range of Heat Source Temperatures and Capacities

Preißinger

Brüggemann

2017

Energies

View full text Add to dashboard Cite

Industrial waste heat recovery by means of an Organic Rankine Cycle (ORC) can contribute to the reduction of CO 2 emissions from industries. Before market penetration, high efficiency modular concepts have to be developed to achieve appropriate economic value for industrial decision makers. This paper aims to investigate modularly designed ORC systems from a thermoeconomic point of view. The main goal is a recommendation for a suitable chemical class of working fluids, preferable ORC design and a range of heat source temperatures and thermal capacities in which modular ORCs can be economically feasible. For this purpose, a thermoeconomic model has been developed which is based on size and complexity parameters of the ORC components. Special emphasis has been laid on the turbine model. The paper reveals that alkylbenzenes lead to higher exergetic efficiencies compared to alkanes and siloxanes. However, based on the thermoeconomic model, the payback periods of the chemical classes are almost identical. With the ORC design, the developed model and the boundary conditions of this study, hexamethyldisiloxane is a suitable working fluid and leads to a payback period of less than 5 years for a heat source temperature of 400 to 600 • C and a mass flow rate of the gaseous waste heat stream of more than 4 kg/s.

show abstract

Organic Working Fluid Optimization for Space Power Cycles

Cited by 24 publications

References 16 publications

Thermal Stability of Hexamethyldisiloxane (MM) for High-Temperature Organic Rankine Cycle (ORC)

Thermal Stability of Hexamethyldisiloxane (MM) for High-Temperature Organic Rankine Cycle (ORC)

Active subspaces for the optimal meanline design of unconventional turbomachinery

Thermoeconomic Evaluation of Modular Organic Rankine Cycles for Waste Heat Recovery over a Broad Range of Heat Source Temperatures and Capacities

Contact Info

Product

Resources

About