Thermodynamic Evaluation of Energy Recovery System For Heavy Duty Diesel Engine by using Organic Rankine Cycle

The internal combustion engine is used daily for transportation and energy production beside their low thermal efficiency level. Most of the thermal energy in such engines is wasted. Therefore, energy recovery in diesel engines are crucial in order to enhance their performance and the environmental penalty. The present paper discusses the energy recovery potential of internal combustion engine cooling system by using organic Rankine cycle (ORC). An  heavy-duty diesel engine that has a maximum brake power rating of about 345 kW is selected for the energy recovery potential investigation. Around eighty different type organic fluid is considered as the working fluid. Operability margin of each fluid as a function of  cooling system pressure is identified based on fix evaporator and condensation conditions. The mass flow rates required for each ORC system are computed together with the cycle thermal efficiencies for each cycle conditions. The results show that such ORC system is capable of recovering up to 13.6% of the wasted heat which corresponds to a power recovery of about 24 kW and enhances the diesel engine brake efficiency by 2.4%

Efficiency of a high-pressure turbine tested in a compression tube facility

Highly loaded single stage gas turbines are being developed to minimize the turbine size and weight. Such highly loaded turbines often result in transonic flows, which imply a reduction in the efficiency due to the shock losses. The efficiency of a turbine is defined as the ratio between the real work extracted by the turbine rotor from the fluid and the maximum available enthalpy for a given pressure ratio. The relationship between turbine performance and design parameters is not yet fully comprehended due to the complexity of the flow field and unsteady flow field interactions. Hence, experimental and numerical studies remain necessary to understand the flow behavior at different conditions to advance the state of the art of the prediction tools. The purpose of the current research is to develop a methodology to determine the efficiency with an accuracy better than 1 % in a cooled and uncooled high pressure (HP) turbine tested in a short duration facility with a running time of about 0.4s. Such low level of uncertainty requires the accurate evaluation of a large number of quantities simultaneously, namely the mass flow of the mainstream, the coolant, and leakage flows properties, the inlet total pressure and total temperature, the stage exit total pressure, the shaft power, the mechanical losses and the heat transfer. The experimental work is carried out in a compression tube facility that allows testing the turbine at the temperature ratios, Re and Mach numbers encountered in real engines. The stage mass flow is controlled by a variable sonic throat located downstream of the stage exit. Due to the absence of any brake, the turbine power is converted into rotor acceleration. The accurate measurement of this acceleration as well as those of the inertia and the rotational speed provides the shaft power. The inertia of the whole rotating assembly was accurately determined by accelerating and decelerating the shaft with a known energy. The mass-flow is derived from the measured turbine inlet total pressure and the vane sonic throat. The turbine sonic throat was evaluated based on a zero-dimensional model of the turbine. The efficiencies of two transonic turbines are measured at design and off-design conditions. The turbine design efficiency is obtained as 91.8 %. The repeatability of the measurements for 95% confidence level varies between 0.3 % and 1.1 % of the efficiency depending on the test case. The theoretical uncertainty level of 1.2 % is mainly affected by the uncertainty of exit total pressure measurements. Additionally, the effect of vane trailing edge shock formations and their interactions with the rotor blade are analyzed based on the experimental data, the numerical tools and the loss correlations. The changes of blade and vane performances are measured at mid-span for three different pressure ratios which influence the vane and rotor shock mechanisms. Moreover, the unsteady forces on the rotor blades and the rotor disk were calculated by integration of the unsteady static pressure field on the rotor surface.(FSA 3) -- UCL, 200

Experimental Investigation of Effusion and Film Cooling for Gas Turbine Combustor

Experimental study was conducted to understand the heat transfer characteristics of film or effusion cooled test plates that represent the gas turbine combustor liner. Two effusion cooling test plates having different hole angles (30 and 75° with horizontal) were used. Film cooling tests were conducted by six different slot geometries. Test geometries were the scaled-up model of real combustor liner. Three different blowing ratios were applied for each test plate geometry. Surface cooling effectiveness was determined for each test condition by measuring the surface temperature distribution by infrared thermography technique. Effects of geometrical and flow parameters on cooling effectiveness were investigated

A Test Bench for Gas Turbine Combustor Cooling Investigations

Design and installation of a test bench for combustion chamber cooling investigations of gas turbines are carried out. The test bench mainly consists of a radial fan, an electrical heater, an air tunnel, a test section, and cooling air supply system. The combustor liner is presented by a flat test plate which is a scaled-up model of a real combustor geometry. Main flow can be provided at a temperature in the range of 298-573 K, which enables a wide range of density and blowing ratio between the main flow and the coolant. The surface temperature distribution of the test plate is measured by infrared thermography technique to determine the adiabatic cooling effectiveness. The test bench enables to investigate the effects of different geometrical and flow parameters on effusion and film cooling effectiveness

Flow Field Investigation of Rib Roughened Serpentine channel

This paper presents numerical flow field and heat transfer analysis of a channel consisting of upstream and downstream channels and a 180° bend. Turbulators (rib) with a square cross-section are placed in the straight part of the channels in order to enhance the heat transfer while flow enters to the model at fully developed conditions at Reynolds numbers of 20000. A constant heat flux boundary condition is provided from the bottom wall of the model. Numerical simulations are performed by a commercial solver using realizable k-ε turbulence model with enhanced wall treatment. The flow field development and evaluation of pressure drop accounted by each rib are analyzed along the channel. The effects of ribs to the flow field are characterized by wall shear distribution. The effect of u-bend on the downstream flow field is investigated

Sergio Lavagnoli Aerodynamic Analysis of an Innovative Low Pressure Vane Placed in an s-Shape Duct

In this paper the aerodynamics of an innovative multisplitter low pressure (LP

Synthesis of a Multifunctional Quinoxaline and Benzodithiophene Bearing Polymer and Its Electrochromic Device Applications

A quinoxaline (Qx) and benzodithiophene (BDT) comprising of random copolymers, namely poly(5-(6-(5-(4,8-bis((2-ethylhexyl)oxy)benzo[1,2-b:4,5-b ']dithiophen-2-yl)-4-(2-ethylhexyl)thiophen-2-yl)-4,8-bis ((2-ethylhexyl)oxy)benzo[1,2-b:4,5-b ']dithiophen-2-yl)-2,3-bis(3,4-bis(octyloxy)phenyl)quinoxaline) (PQBT), is synthesized via Stille polycondensation reaction. To investigate the effect of the pi-bridge on the electrochromic properties, 3-(2-ethylhexyl) thiophene is incorporated the between Qx and BDT moiety. The resulting random copolymer is characterized by NMR spectroscopy, gel permeation chromatography (GPC), attenuated total reflectance-Fourier-transform infrared spectroscopy (ATR-FTIR), and scanning electron microscopy (SEM). PQBT exhibits ambipolar and multichromic characteristics and is highly soluble in common solvents. Optoelectronic studies reveal two well-separated absorption bands having maxima at 500 and 532 nm with 1.83 eV optical band gap (E-g(op)). PQBT exhibits orange color in the neutral state with brown, green, and blue colors in the intermediate, oxidized, and reduced states, respectively. Subsequently, a PQBT and poly-3,4-ethylenedioxythiophene (PEDOT)-bearing prototype bilayer electrochromic device working between orange and blue colors is constructed and characterized

Synthesis of a Multifunctional Quinoxaline and Benzodithiophene Bearing Polymer and Its Electrochromic Device Applications

A quinoxaline (Qx) and benzodithiophene (BDT) comprising of random copolymers, namely poly(5-(6-(5-(4,8-bis((2-ethylhexyl)oxy)benzo[1,2-b:4,5-b ']dithiophen-2-yl)-4-(2-ethylhexyl)thiophen-2-yl)-4,8-bis ((2-ethylhexyl)oxy)benzo[1,2-b:4,5-b ']dithiophen-2-yl)-2,3-bis(3,4-bis(octyloxy)phenyl)quinoxaline) (PQBT), is synthesized via Stille polycondensation reaction. To investigate the effect of the pi-bridge on the electrochromic properties, 3-(2-ethylhexyl) thiophene is incorporated the between Qx and BDT moiety. The resulting random copolymer is characterized by NMR spectroscopy, gel permeation chromatography (GPC), attenuated total reflectance-Fourier-transform infrared spectroscopy (ATR-FTIR), and scanning electron microscopy (SEM). PQBT exhibits ambipolar and multichromic characteristics and is highly soluble in common solvents. Optoelectronic studies reveal two well-separated absorption bands having maxima at 500 and 532 nm with 1.83 eV optical band gap (E-g(op)). PQBT exhibits orange color in the neutral state with brown, green, and blue colors in the intermediate, oxidized, and reduced states, respectively. Subsequently, a PQBT and poly-3,4-ethylenedioxythiophene (PEDOT)-bearing prototype bilayer electrochromic device working between orange and blue colors is constructed and characterized