Experimental Study on the Performance of the Single Screw Expander Prototype by Optimizing Configuration

2012 ◽  
Author(s):  
Wei Wang ◽  
Yu-ting Wu ◽  
Guo-dong Xia ◽  
Chong-fang Ma ◽  
Jing-fu Wang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Consumption Rate ◽  
Experimental Results ◽  
Thermodynamic Efficiency ◽  
Single Screw ◽  
Gas Consumption

Improving thermodynamic efficiency of prime movers is the key issue for efficient utilization of low temperature heat resources. Because of many good characteristics, the single screw expander is perhaps a good choice. Precisions in manufacture and assembly are very important factors to the performance of single screw expanders. In this paper, experimental results of the first single screw expander prototype made by ourselves was analyzed and reported for the first time. From the experimental data, the power output of the prototype was about 5kW, but the gas consumption rate was above 105kg/kWh, so the shaft efficiency was only 34% or so. The results indicated that internal leakage was very serious. Hence, the second single screw expander prototype was manufactured. The gap between gate rotor and shell of the new prototype was reduced. The gap is about 0.02mm. From the new experimental data, the mass flow rate was significantly decreased. However, the power output was only 1.4kW. So, the gas consumption rate was even more than the first prototype. The reason of bad experimental results may arise from the too large friction between screw, gate rotor and shell in the case of small gap. So, we manufactured the third single screw expander prototype, which is 0.04mm in gap. From the experimental data, the maximum power output was about 4.5kW, but the mass flow rate was decreased sharply. So the gas consumption rate was about 60kg/kWh, and the shaft efficiency was about 60%. The result indicated that the performance of the single screw expander was remarkable improved by optimizing its configuration.

scholarly journals Experimental Investigation and Modeling of Inertance Tubes

2005 ◽  
Vol 127 (5) ◽  
pp. 1029-1037 ◽  
Author(s):  
L. O. Schunk ◽  
G. F. Nellis ◽  
J. M. Pfotenhauer
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Acoustic Power ◽  
Operating Conditions ◽  
Thermodynamic Efficiency ◽  
Pulse Tube ◽  
Design Charts ◽  
Wide Range ◽  
Pulse Tube Refrigerators

Growing interest in larger scale pulse tubes has focused attention on optimizing their thermodynamic efficiency. For Stirling-type pulse tubes, the performance is governed by the phase difference between the pressure and mass flow, a characteristic that can be conveniently adjusted through the use of inertance tubes. In this paper we present a model in which the inertance tube is divided into a large number of increments; each increment is represented by a resistance, compliance, and inertance. This model can include local variations along the inertance tube and is capable of predicting pressure, mass flow rate, and the phase between these quantities at any location in the inertance tube as well as in the attached reservoir. The model is verified through careful comparison with those quantities that can be easily and reliably measured; these include the pressure variations along the length of the inertance tube and the mass flow rate into the reservoir. These experimental quantities are shown to be in good agreement with the model’s predictions over a wide range of operating conditions. Design charts are subsequently generated using the model and are presented for various operating conditions in order to facilitate the design of inertance tubes for pulse tube refrigerators. These design charts enable the pulse tube designer to select an inertance tube geometry that achieves a desired phase shift for a given level of acoustic power.

Experimental Investigation of a Flat Plate Photovoltaic/Thermal Collector

2018 ◽  
Author(s):  
Mohamad Modrek ◽  
Ali Al-Alili
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Electrical Power ◽  
Solar Thermal ◽  
Pv Panel ◽  
Solar Thermal Collectors ◽  
Electrical Power Output ◽  
Electrical Output

Photovoltaic thermal collectors (PVT) combines technologies of photovoltaic panels and solar thermal collectors into a hybrid system by attaching an absorber to the back surface of a PV panel. PVT collectors have gained a lot of attention recently due to the high energy output per unit area compared to a standalone system of PV panels and solar thermal collectors. In this study, performance of a liquid cooled flat PVT collector under the climatic conditions of Abu Dhabi, United Arab Emirates was experimentally investigated. The electrical performances of the PVT collector was compared to that of a standalone PV panel. Moreover, effect of sand accumulation on performance of PVT collectors was examined. Additionally, effect of mass flow rate on thermal and electrical output of PVT collector was studied. Electrical power output is slightly affected by changes in mass flow rate. However, thermal energy increased by 22% with increasing flow rate. Electrical power output of a PV panel was found to be 38% lower compared to electrical output of PVT collectors. Dust accumulation on PVT surface reduced electrical power output up to 7% compared with a reference PVT collector.

Behavior of Thermal Effects and Velocity-Slip on Performance of Externally Pressurized Porous Incompressible Gas Thrust Bearing

1979 ◽  
Vol 46 (2) ◽  
pp. 465-468 ◽  
Author(s):  
V. K. Kapur ◽  
J. S. Yadav
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Effects ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Velocity Slip ◽  
Experimental Results ◽  
Slip Condition ◽  
Static Stiffness

In the present analysis, the interactions of thermal effects and velocity slip on the performance of externally pressurized porous incompressible gas thrust bearing have been studied. Numerical results for load capacity, mass flow rate, and static stiffness have been obtained and their behavior is illustrated in figures. The results for slip as well as no-slip condition have also been compared with the experimental results of Gargiulo and Gilmour [7].

scholarly journals Off-Design Performances of an Organic Rankine Cycle for Waste Heat Recovery from Gas Turbines

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1105 ◽  
Author(s):  
Carlo Carcasci ◽  
Lapo Cheli ◽  
Pietro Lubello ◽  
Lorenzo Winchler
Keyword(s):  
Gas Turbine ◽  
Mass Flow Rate ◽  
Air Temperature ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Ambient Air ◽  
Air Mass

This paper presents an off-design analysis of a gas turbine Organic Rankine Cycle (ORC) combined cycle. Combustion turbine performances are significantly affected by fluctuations in ambient conditions, leading to relevant variations in the exhaust gases’ mass flow rate and temperature. The effects of the variation of ambient air temperature have been considered in the simulation of the topper cycle and of the condenser in the bottomer one. Analyses have been performed for different working fluids (toluene, benzene and cyclopentane) and control systems have been introduced on critical parameters, such as oil temperature and air mass flow rate at the condenser fan. Results have highlighted similar power outputs for cycles based on benzene and toluene, while differences as high as 34% have been found for cyclopentane. The power output trend with ambient temperature has been found to be influenced by slope discontinuities in gas turbine exhaust mass flow rate and temperature and by the upper limit imposed on the air mass flow rate at the condenser as well, suggesting the importance of a correct sizing of the component in the design phase. Overall, benzene-based cycle power output has been found to vary between 4518 kW and 3346 kW in the ambient air temperature range considered.

Design and Testing of a Can Combustor for a Small Gas Turbine Application

2013 ◽  
Author(s):  
K. V. L. Narayana Rao ◽  
N. Ravi Kumar ◽  
G. Ramesha ◽  
M. Devathathan
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Turbines ◽  
Pressure Loss ◽  
High Energy ◽  
Experimental Results ◽  
High Mass ◽  
Test Facility ◽  
Design Requirements

Can type combustors are robust, with ease of design, manufacturing and testing. They are extensively used in industrial gas turbines and aero engines. This paper is mainly based on the work carried out in designing and testing a can type combustion chamber which is operated using JET-A1 fuel. Based on the design requirements, the combustor is designed, fabricated and tested. The experimental results are analysed and compared with the design requirements. The basic dimensions of the combustor, like casing diameter, liner diameter, liner length and liner hole distribution are estimated through a proprietary developed code. An axial flow air swirler with 8 vanes and vane angle of 45 degree is designed to create a re-circulation zone for stabilizing the flame. The Monarch 4.0 GPH fuel nozzle with a cone angle of 80 degree is used. The igniter used is a high energy igniter with ignition energy of 2J and 60 sparks per minute. The combustor is modelled, meshed and analysed using the commercially available ansys-cfx code. The geometry of the combustor is modified iteratively based on the CFD results to meet the design requirements such as pressure loss and pattern factor. The combustor is fabricated using Ni-75 sheet of 1 mm thickness. A small combustor test facility is established. The combustor rig is tested for 50 Hours. The experimental results showed a blow-out phenomenon while the mass flow rate through the combustor is increased beyond a limit. Further through CFD analysis one of the cause for early blow out is identified to be a high mass flow rate through the swirler. The swirler area is partially blocked and many configurations are analysed. The optimum configuration is selected based on the flame position in the primary zone. The change in swirler area is implemented in the test model and further testing is carried out. The experimental results showed that the blow-out limit of the combustor is increased to a good extent. Hence the effect of swirler flow rate on recirculation zone length and flame blow out is also studied and presented. The experimental results showed that the pressure loss and pattern factor are in agreement with the design requirements.

An Experimental Study of the Flow of R-407C in an Adiabatic Spiral Capillary Tube

2009 ◽  
Vol 1 (4) ◽  
Author(s):  
M. K. Mittal ◽  
R. Kumar ◽  
A. Gupta
Keyword(s):  
Experimental Data ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Capillary Tube ◽  
Flow Characteristics ◽  
Flow Rates ◽  
Tube Test ◽  
Mass Flow Rates ◽  
R 134A

The objective of this study is to investigate the effect of coiling on the flow characteristics of R-407C in an adiabatic spiral capillary tube. The characteristic coiling parameter for a spiral capillary tube is the coil pitch; hence, the effect of the coil pitch on the mass flow rate of R-407C was studied on several capillary tube test sections. It was observed that the coiling of the capillary tube significantly reduced the mass flow rate of R-407C in the adiabatic spiral capillary tube. In order to quantify the effect of coiling, the experiments were also conducted for straight a capillary tube, and it was observed that the coiling of the capillary tube reduced the mass flow rate in the spiral tube in the range of 9–18% as compared with that in the straight capillary tube. A generalized nondimensional correlation for the prediction of the mass flow rates of various refrigerants was developed for the straight capillary tube on the basis of the experimental data of R-407C of the present study, and the data of R-134a, R-22, and R-410A measured by other researchers. Additionally, a refrigerant-specific correlation for the spiral capillary was also proposed on the basis of the experimental data of R-407C of the present study.

Experimental investigation and optimization of a low-temperature thermoelectric module with different operating conditions

2019 ◽  
Vol 16 (3) ◽  
pp. 368-376
Author(s):  
Dipak Sudam Patil ◽  
Rachayya R. Arakerimath ◽  
Pramod V. Walke
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
External Load ◽  
Thermoelectric Module ◽  
Load Resistance ◽  
Operating Conditions ◽  
Content Type ◽  
Heater Temperature

Purpose This paper aims to present an experimental investigation and optimization of a low-temperature thermoelectric module to examine the influence of the main operating conditions. Design/methodology/approach In this work, a comparison was made by varying the various operating parameters such as heat source temperature, the flow rate of the cold fluid and the external load resistance. A Taguchi method was applied to optimize the parameters of the system. Three factors, including the external load resistance, mass flow rate of water (at the heat sink side) and heater temperature (at the heat source side) along with different levels were taken into account. Analysis of variance was used to determine the significance and percentage contribution of each parameter. Findings The experimental results show that the maximum power output 8.22W and the maximum conversion efficiency 1.11 per cent were obtained at the heater temperature of 240°C, the cold fluid mass flow rate of 0.017 kg/s, module temperature difference of 45°C and the load resistance of 5 O. It was observed that the optimum parameter levels for maximum power output determined as 5 O external load resistance, 0.17 kg/s mass flow rate of water and 240°C heater temperature (A1B3C3). It reflects that these parameters influence on the optimum conditions. The heater temperature is the most significant parameter on the power output of the thermoelectric module. Originality/value It is clear from the confirmation test that experimental values and the predicted values are in good agreement.

scholarly journals The effect of cohesion on the discharge of a granular material through the orifice of a silo

2021 ◽  
Vol 249 ◽  
pp. 08014
Author(s):  
Adrien Gans ◽  
Pascale Aussillous ◽  
Blanche Dalloz ◽  
Maxime Nicolas
Keyword(s):  
Granular Material ◽  
Numerical Simulations ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Experimental Results ◽  
Numerical Investigations ◽  
Silo Discharge

We present the results of both experimental and numerical investigations of the silo discharge for a cohesive granular material. In our study, thanks to a cohesion-controlled granular material (CCGM) we propose to investigate the effect of the cohesive length lc, on the discharge of a silo for two different configurations, one axisymmetrical, and one quasi-2D rectangular silo. In both configurations, an adjustable bottom is used to control the size of the orifice. As observed for cohesionless granular material by previous studies, the mass flow rate and the density through an orifice are mostly controlled by the diameter of the orifice D. The experimental results of the quasi-2D silo are compared with continuum numerical simulations.

Dynamic Behavior and Off-Design Performance Analysis of Solar Driven ORC Using Scroll Expanders

2019 ◽  
Author(s):  
Ying Zhang ◽  
Arun Kumar Narasimhan ◽  
Mengjie Bai ◽  
Li Zhao ◽  
Shuai Deng ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
System Level ◽  
Working Fluid ◽  
Small Scale ◽  
Solar Insolation ◽  
Design Performance ◽  
Fluid Mass

Abstract Solar driven ORC system is a possible solution for small-scale power generation. A scroll expander is considered due to its better suitability among other positive displacement expanders for small-scale power outputs. This work conducted a test of an ORC system with an expansion valve by varying the working fluid mass flow rate in two scenarios. A dynamic system-level model of ORC was developed and validated with experimental data. The validated model was used to predict the ORC performance considering off-design conditions of expander and solar insolation. The experimental data showed that pressures and temperatures exhibited the same trend as that of the working fluid mass flow rate, of which the evaporation pressure was the most sensitive to this variation. The simulation results are in good agreement with the experimental results. Results from the dynamic model showed that the ORC power output was underestimated by up to 54.7%, when off-design performance of expander was not considered. Considering the expander off-design performance and solar insolation, a highest thermal efficiency of 7.6% and an expander isentropic efficiency of 80.6% were achieved.

Power Enhancement of Gas Turbine Plant by Intake Air Fog Cooling

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
J. P. Yadav ◽  
Bharat Raj Singh ◽  
Onkar Singh
Keyword(s):  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Gas Turbines ◽  
Ambient Air ◽  
Summer Season ◽  
Ambient Conditions ◽  
Power Enhancement

Although gas turbines are known as constant volume machines, but its performance considerably depends upon the ambient air temperature and mass flow rate. During summer season the density of the air decreases which affects the mass flow rate and ultimately the power output of a gas turbine is reduced. In order to overcome this situation several techniques are already in the practice and one of the most effective and economical is adopting the inlet fog cooling, and this technique basically enhances the power output of the machine. The cooling of ambient air by fog cooling up to wet bulb temperature increases the mass flow rate on account of increase in air density, as a result it ultimately increases the power output of a gas turbine. Fogging is applied with consideration of relative humidity of ambient air not only during summer season but also during dry days of summer season in order to increase the power output of gas turbine. This paper describes the effect on percentage enhancement of power out adopting various fuel options with low and high humidity ambient conditions. The result indicates the potential increase in the power output up to 14%. It is also observed that the total cost of power production increases due to increase in fuel consumption on account of enhanced power output. Thus the best suitable selling cost of power should be selected to compensate the increased investment on fuel cost.

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