Comparison of a Novel Organic-Fluid Thermofluidic Heat Converter and an Organic Rankine Cycle Heat Engine

Abstract

Abstract:The Up-THERM heat converter is an unsteady, two-phase thermofluidic oscillator that employs an organic working fluid, which is currently being considered as a prime-mover in small-to medium-scale combined heat and power (CHP) applications. In this paper, the Up-THERM heat converter is compared to a basic (sub-critical, non-regenerative) organic Rankine cycle (ORC) heat engine with respect to their power outputs, thermal efficiencies and exergy efficiencies, as well as their capital and specific costs. The study focuses on a pre-specified Up-THERM design in a selected application, a heat-source temperature range from 210°C to 500°C and five different working fluids (three n-alkanes and two refrigerants). A modeling methodology is developed that allows the above thermo-economic performance indicators to be estimated for the two power-generation systems. For the chosen applications, the power output of the ORC engine is generally higher than that of the Up-THERM heat converter. However, the capital costs of the Up-THERM heat converter are lower than those of the ORC engine. Although the specific costs (£/kW) of the ORC engine are lower than those of the Up-THERM converter at low heat-source temperatures, the two systems become progressively comparable at higher temperatures, with the Up-THERM heat converter attaining a considerably lower specific cost at the highest heat-source temperatures considered.

Hybrid Electric Vehicle Performance with Organic Rankine Cycle Waste Heat Recovery System

“…The electric drive mode, on the other hand, uses only the electric motor to provide vehicle motion while the engine is disengaged. In hybrid mode, the vehicle is driven by both the ICE and the electric motor, while in the power split mode the engine is not only providing motion, but also charging the battery pack [15][16][17][18][19]. Finally, the braking mode includes the regenerative brake, the energy of which is stored in the battery for further use.…”

“…On the other hand, an electric turbocompound setup can exploit the exhaust gas energy to gain electrical power that can be saved in a battery or used to support several electric components of the vehicle, increasing the fuel economy up to 10%. Currently, approximately a 2% reduction in fuel consumption can be offered by thermoelectric generators, which use the exhaust gas heat to produce electricity directly via thermoelectric conversion means [2,17,20]. This study focuses on the bottoming cycle type of waste heat recovery, which employs thermodynamic cycles to gain energy out of the exhaust gas heat.…”

Case Study of an Organic Rankine Cycle (ORC) for Waste Heat Recovery from an Electric Arc Furnace (EAF)

“…Although these technologies are more mature, other earlier-stage options are also being currently developed, including various Stirling [14], thermoacoustic [15] and thermofluidic heat engines [16]. In particular, the Non-Inertive-Feedback Thermofluidic Engine (NIFTE) [17,18] and the Up-THERM heat converter [19,20] have been shown to be thermodynamically and economically (due to their small number of moving parts) competitive with established technologies such as ORCs [21].…”

Thermoacoustic Stirling power generation from LNG cold energy and low-temperature waste heat

“…They require many engineering efforts for the complicated precision moving parts, and therefore are expensive. On the contrary, a recently proposed two-phase thermofluidic oscillator requires little engineering and has few moving parts [39][40][41][42]. They have low capital, maintenance and operating costs, however, suffer from low efficiencies.…”