Energy Recovery Turbine Research Articles

Investigation of the collaborative optimization of the aerodynamic and anti-erosion performance of a two-stage energy recovery turbine

Investigation of the collaborative optimization of the aerodynamic and anti-erosion performance of a two-stage energy recovery turbine

Research on the Internal Flow Mechanisms and Pressure Fluctuation Characteristics of Seawater Reverse Osmosis Energy Recovery Turbines

Research on the Internal Flow Mechanisms and Pressure Fluctuation Characteristics of Seawater Reverse Osmosis Energy Recovery Turbines

Research on the influence mechanism of internal flow characteristics on energy conversion in radial energy recovery turbines under multiple conditions

Research on the influence mechanism of internal flow characteristics on energy conversion in radial energy recovery turbines under multiple conditions

Thermodynamic analysis of a new electric environmental control system with energy recovery turbine

Thermodynamic analysis of a new electric environmental control system with energy recovery turbine

Multiobjective Optimization Study On the Aerodynamic Performance and Anti-Erosion Characteristics of a Single-Stage Dusty Flue Gas Turbine

Abstract Solid particle erosion of dusty energy recovery turbine blades has a great impact on the operating economics and safety of the unit. To mitigate the erosion of blade and improve the aerodynamic performance of the turbine, a multiobjective optimization method for turbine cascade based on the experimental design method, genetic algorithm and CFD multiphase flow simulation was developed. The optimization results show that the number of stator and rotor blades and the trailing edge angle at 50% blade span are the main parameters affecting the efficiency and blade erosion of the dusty turbine. By reducing the number of stator blades and the circumferential bending angle of the stator trailing edge, the impingement velocity and impingement probability of particles impinging on the stator trailing edge decrease by 7.5%~16.8% and 8.9%~46.2%, respectively. Additionally, compared with the original design, the flow separation loss and secondary flow intensity of the rotor cascade are suppressed by adjusting the load distribution and inlet attack angle of the rotor; thus, the turbine efficiency effectively improves by 2.28%. Meanwhile, the optimized blade reduces the particle impingement velocity and probability on the rotor leading edge, and the erosion condition of the rotor leading edge decreases by 70%.

Numerical optimisation of the active lift turbines using OpenFoam's overset method

This work presents a preliminary study of the numerical optimization of "active lift turbine" using computational fluid dynamics (CFD). This active lift turbine is designed to improve efficiency of vertical axis energy recovery turbines (wind and tidal turbines). It uses a crank rod system to convert normal forces into momentum in order to improve the yield.
 After a validation work of CFD model in two dimensions, the numerical optimization of the tidal turbine system is carried out. In fact, due to the specific characteristics of the active lift turbine, the blades do not follow a circular trajectory (Fig. \ref{fig:combined}). The OpenFoam overset module is therefore chosen because it allows to control the motion of the blades easily \cite{Chalmers}. The Overset method allows a good performance evaluation and limits the risk of numerical divergence that could be caused by mesh deformation methods; Moreover it limits the computation time compared to remeshing methods. However, it is more expensive than a more traditional Arbitrary Mesh Interface method \cite{Openfoam}, which is not suitable for the active lift turbine simulations.
 The impact of several parameters on the performances is studied. The simulations are performed for a range of operating conditions including different inflow velocities, angles of attack and active flow turbine settings (like the amplitude of the radius variation, see Fig \ref{fig:combined}). The results are evaluated in terms of the turbine power output and efficiency.
 The results show the importance of numerical simulation for the development of new types of energy recovery systems. It allows a better understanding of the interactions between the turbine and the fluid, and of the operation of such systems.
 Further studies are required for the active lift turbine: conventional attempts at optimisation are not perfectly suited to this system. Improving the lift/drag ratio makes less sense when the normal forces should also be taken into account to improves the performances. Furthermore, other aspects of operation should be analysed: variation of the turbulence rate, implementation of boundary layer re-attachment systems...

Optimization of energy recovery turbine in demineralized water treatment system of power station by Box–Behnken Design method

Optimization of energy recovery turbine in demineralized water treatment system of power station by Box–Behnken Design method

Water-renewable energy Nexus: Optimization of geothermal energy-powered seawater desalination systems

Water-renewable energy Nexus: Optimization of geothermal energy-powered seawater desalination systems

Experimental Outdoor Public Lighting Installation Powered by a Hydraulic Turbine Installed in the Municipal Water Supply Network

Sustainability and energy prices make the use of energy obtained from renewable sources on an urban scale and for isolated local facilities necessary for municipal authorities. Moreover, when the demand of energy is at night, as for street lighting installations, the use of accumulative systems is necessary, which means a major drawback due to a short lifetime expectancy and high cost. The use of batteries can require more than 70% of the budget of these lighting systems and has a critical impact in the project. The problem to solve is finding different renewable energy sources that can produce energy throughout the day, especially during the night, at the same time at which it is consumed. As one of the competences of municipal authorities is water supply networks, this paper analyzes the use of energy recovery turbines within these installations as an alternative to photovoltaic generators. To study the viability and effectiveness of this alternative, the water flows available in the network of a medium-size municipality were monitored and analyzed in depth to assess the amount of recoverable energy. In addition, an energy recovery turbine (ERT) station was set up, installing a bypass around one of the pressure-reducing valves (PRV) of the installation where energy is dissipated without practical use. The results obtained imply that the system proposed has economical and technical viability, is reliable and guarantees full service in all the seasons’ conditions. Moreover, the needs of the energy storage capacity are much lower (~8%) than with solar panels.

Numerical and experimental investigations on inflow loss in the energy recovery turbines with back-curved and front-curved impeller based on the entropy generation theory

Numerical and experimental investigations on inflow loss in the energy recovery turbines with back-curved and front-curved impeller based on the entropy generation theory

Thermodynamic analysis of gravity assisted solar-powered reverse osmosis unit for greenhouses situated in a depleted zone

The Sabkha-Tah region of Western Sahara is a location where adverse weather conditions make it difficult for the conventional farming of certain crops. However, the region is uniquely situated in a depleted zone 60 m below sea-level. In this unique energy, water, and food nexus study, an analysis of a novel multi-generation system that harnesses the surrounding geography to produce power, cooling, and freshwater for a greenhouse situated in the Sabkha-Tah region is performed. The system utilises the Atlantic Ocean's hydrostatic pressure to decrease the power consumption of the reverse osmosis (RO) water desalination unit. A solar-powered Rankine cycle is used to meet the energy demands of the RO and absorption cooling units. A thermodynamic analysis of the system is performed, and the results demonstrate that the use of an energy recovery turbine along with the geographical advantage of the region decreased the power requirement of the RO unit. The system demonstrates that 46.18 kW of energy can be saved when using the water's hydrostatic pressure. The net power consumption in the RO unit is 226 kW, and it can provide 90 m3/h of freshwater. The energy required to produce 1 m3 of freshwater is 2.51 kWh, and the overall energy and exergy efficiencies for the multi-generation system are calculated to be 60.8% and 29.76%, respectively.

Numerical Simulation on the Influence of Rotating Speed on the Hydraulic Loss Characteristics of Desalination Energy Recovery Turbine

The performance of energy recovery turbine (ERT) directly determines the cost and energy consumption of reverse osmosis desalination. In order to study the performance and loss mechanisms of ERT under different conditions, the external characteristics and the losses of different components were quantitatively analyzed. The loss mechanisms of each component in the turbine were revealed through the comparative analysis of the internal flow field. The results show that the efficiency is 2.2% higher than that at the design speed when turbine runs at n = 22000 r/min. The impeller losses account for more than 67% of the total losses. The impeller loss is mainly observed at the leading edge. The vortex on the pressure side of the leading edge is caused by the impact effect, while the vortex on the suction side of the leading edge is caused by the flow separation. With the increase in the rotating speed, the loss caused by flow separation in impeller decreases obviously. The volute loss is mainly observed near the tongue, which is caused by the flow separation at the tongue. The design of the tongue is very important to the performance of the volute. The turbulent kinetic energy (TKE) and loss decrease with the increase in the rotating speed. The loss in the draft tube is mainly observed at the inlet core. With the increase in the rotating speed, the turbulence pulsation and the radial pressure fluctuation amplitude reduce. Therefore, the turbine can be operated at the design or slightly higher than the design rotating speed under the condition that both the hydraulic condition and the intensity are satisfied, which are conducive to the efficient utilization of energy.

Numerical and Experimental Investigations on Inflow Loss in the Energy Recovery Turbines with Back-Curved and Front-Curved Impeller Based on the Entropy Generation Theory

Numerical and Experimental Investigations on Inflow Loss in the Energy Recovery Turbines with Back-Curved and Front-Curved Impeller Based on the Entropy Generation Theory

Thermodynamic analysis of a novel fossil‐fuel–free energy storage system with a trans‐critical carbon dioxide cycle and heat pump

Author(s): Hao, Y; He, Q; Liu, W; Pan, L; Oldenburg, CM | Abstract: This paper presents and analyzes a novel fossil-fuel–free trans-critical energy storage system that uses CO2 as the working fluid in a closed loop shuttled between two saline aquifers or caverns at different depths: one a low-pressure reservoir and the other a high-pressure reservoir. Thermal energy storage and a heat pump are adopted to eliminate the need for external natural gas for heating the CO2 entering the energy recovery turbines. We carefully analyze the energy storage and recovery processes to reveal the actual efficiency of the system. We also highlight thermodynamic and sensitivity analyses of the performance of this fossil-fuel–free trans-critical energy storage system based on a steady-state mathematical method. It is found that the fossil-fuel–free trans-critical CO2 energy storage system has good comprehensive thermodynamic performance. The exergy efficiency, round-trip efficiency, and energy storage efficiency are 67.89%, 66%, and 58.41%, and the energy generated of per unit storage volume is 2.12 kW·h/m3, and the main contribution to exergy destruction is the turbine reheater, from which we can quantify how performance can be improved. Moreover, with a higher energy storage and recovery pressure and lower pressure in the low-pressure reservoir, this novel system shows promising performance.

Monitoring Seasonal Variation in Important Physio-Chemical Parameters of Arabian Seawater at Karachi Used for Feeding SWRO

This study reports the analysis of various parameters of seawater upto 3 years used for feeding to seawater desalination (SWRO) plant at French Beach, Arabian sea, Karachi city, Pakistan. The work highlights the monitoring of essential parameters of seawater intake to reverse osmosis plant for pre-treatment loop designing and optimizing the operational cost. The study was planned as limited data was available internationally from this region, which includes pH, turbidity, temperature, total dissolved solids (TDS) and total suspended solids (TSS) allied with seasonal variations before pretreatment and after getting permeate. The water production capacity of SWRO plant is 100,000 gallon per day having Filmtech polyamide membrane and equipped with energy recovery turbine. It was observed in the period since 2015 to 2017, the monitoring of intake samples i.e. pH, turbidity and temperature showed variation in the range of 7.9-8.1, 8-34 NTU and 21-29 ºC, respectively. The observed value of TDS and TSS of seawater were 38.0-39.5 g/L and 18-48 mg/L, respectively. The concentrations of soft metals in seawater were found to be in order of Na > Mg > Ca > K while major anions were Cl− >SO4 2−. The TDS and pH of permeate water found to be in the range of 150-500 mg/L and 6.0-7.5 respectively, while other parameters were within WHO limit.

Design and Simulation of Proton Exchange Membrane Fuel Cell Exhaust Gas Recovery System

The compressed air from high-pressure compressor enters the proton exchange fuel cell and was discharged from the cathode after reacting. This part of the exhaust gas had a certain residual pressure. In order to study the effect of cathode exhaust gas residual pressure recovery on the efficiency of proton exchange membrane fuel cell system, this paper used Simulink software to establish a proton exchange membrane fuel cell exhaust gas recovery system model. In the model, the mass flow of supply air was controlled by controlling the air excess ratio Under this condition, the work done by the exhaust gas on the turbine could account for 18% of the parasitic power consumption. The simulation results showed that this system could increase the system power by up to 13% compared with the energy recovery turbine system, which had good consistency, which was of great significance for PEMFC system design and exhaust gas recovery.

Experimental investigation of failure behavior of the cracked 17-4PH steel blades in a top gas energy recovery turbine

Experimental investigation of failure behavior of the cracked 17-4PH steel blades in a top gas energy recovery turbine

Review of performance improvement of energy recovery turbines in the reverse osmosis desalination

Review of performance improvement of energy recovery turbines in the reverse osmosis desalination

Double multiple stream tube analysis of non-uniform wind stream of exhaust air energy recovery turbine generator

The novel exhaust air energy recovery turbine generator is designed to recover part of energy from a fan-powered exhaust air system which represented by a cooling tower. The discharge wind from the cooling tower varies throughout the radius makes it a non-uniform profile. A vertical axis wind turbine (VAWT) is placed at the outlet of a cooling tower to recover the energy. The VAWT behavior in the non-uniform wind stream from the exhaust air system is studied by experiment and double multiple stream tube (DMST) theory. A novel application of the DMST model is applied for non-uniform wind stream. The experimental results show that best horizontal position of the VAWT is at a distance of about 2/3 of the outlet radius with respect to turbine rotation. Theoretical analysis explains the wind turbine behavior in the non-uniform wind stream as acquired from the experiment. For the selected wind turbine, it is the best to match the highest wind velocity region to the wind turbine at the range of 45° to 115° azimuth angle. This innovative system has a huge potential due to wide application of exhaust air system globally.

Exergetic and economic analysis of two-pass RO desalination proposed plant for domestic water and irrigation

Exergetic and economic analysis of two-pass RO desalination proposed plant for domestic water and irrigation