Performance Characteristics of the Lysholm Engine as Tested for Geothermal Power Applications in the Imperial Valley

1982 ◽  
Vol 104 (1) ◽  
pp. 231-240 ◽  
Author(s):  
R. F. Steidel ◽  
H. Weiss ◽  
J. E. Flower
Keyword(s):  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Energy Output ◽  
Working Fluid ◽  
Two Phase ◽  
Imperial Valley ◽  
Geothermal Resources ◽  
Geothermal Fluids ◽  
Phase Mixture ◽  
Vapor Fraction

This is a description of the performance tests of a Lysholm engine completed at the Lawrence Livermore National Laboratory at the University of California. The Lysholm engine is a rotary displacement engine which can accept a low quality (vapor fraction) two-phase mixture. Generally, the well-head condition of geothermal fluids is a mixture of liquid and vapor, with quality up to 40 percent, although for most liquid dominated geothermal resources the vapor fraction is considerably less than 40 percent. As a thermodynamic process, using mixed phase flow has the potential for using significantly more of the available energy output per pound of fluid, as contrasted with other processes that either transfer heat energy to a second fluid, or use only the vapor fraction and discard the liquid. In our tests, the quality was varied between 8 and 27 percent. Our results indicate that the Lysholm engine can operate well with a two-phase mixture as a working fluid. The maximum observed engine efficiency was 53 percent at 8000 rpm, with an inlet pressure of 190.6 psia, 22.2 percent quality, and an exhaust pressure of 30.6 psia. The best results were observed at the higher speeds and with exhaust to an above-atmospheric backpressure.

Performance of Hero's Turbine Using Two-phase Mixture as Working Fluid : Experimental Results in an Air-water Two-phase System

1984 ◽  
Vol 27 (234) ◽  
pp. 2795-2802 ◽  
Author(s):  
Koji AKAGAWA ◽  
Terushige FUJII ◽  
Sigeo TAKAGI ◽  
Masaru TAKEDA ◽  
Kouich TSUJI
Keyword(s):  
Experimental Results ◽  
Working Fluid ◽  
Phase System ◽  
Two Phase ◽  
Phase Mixture

An Experimental Study of Liquid Entrainment by Rapid Surface Swelling of Two-Phase Mixture in a Vessel

2001 ◽  
Author(s):  
Moon-Hyun Chun ◽  
Kyong-Won Seo ◽  
Hyeng-Kuk Kim
Keyword(s):  
Experimental Study ◽  
Water Level ◽  
Air Flow ◽  
Water Levels ◽  
Working Fluid ◽  
Entrainment Rate ◽  
Two Phase ◽  
Initial Water ◽  
Liquid Entrainment ◽  
Phase Mixture

Abstract An experimental study of liquid entrainment by rapid surface swelling of a two-phase mixture in a vessel has been performed. To investigate the effects of air flow rate and initial water level on the liquid entrainment, a series of experiments have been performed using air and water as working fluid. A total of 64 experimental liquid entrainment rate data have been obtained for various combinations of the test parameters (i.e., for six different initial water levels and various air flow rates) using two test vessels that have the same height but different inner diameters (0.15 and 0.3m, respectively) for vertical bubbly and churn-turbulent flow conditions. An empirical correlation for the liquid entrainment rate, E has been developed in terms of the superficial velocity of air, the initial water level, the density of gas, the surface tension, and the gravity. This correlation shows a good agreement with the present experimental data within ±30% over a wide range of flow parameters.

Mathematical Modeling of Novel Two-Phase Heat Transfer Device for Thermal Management of Light Emitting Diodes

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Karthik S. Remella ◽  
Frank M. Gerner ◽  
Ahmed Shuja
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Thermal Management ◽  
Light Emitting Diodes ◽  
Working Fluid ◽  
Two Phase ◽  
Light Emitting ◽  
Phase Mixture ◽  
Two Phase Heat Transfer ◽  
Transfer Device

The paper introduces a novel two-phase heat transfer device (TPHTD) which is employed in the thermal management of light emitting diodes (LEDs). The heat transfer device structurally resembles a conventional loop heat pipe (LHP) without a compensation chamber, but operates very differently from it. The device is comprised of a central evaporator package and a circular coil that acts as a heat exchanger loop. The working fluid leaving the evaporator has a two-phase mixture quality of approximately 0.2. Having introduced the device, the paper delineates a mathematical model for predicting its thermal performance. The primary objective of the model is to provide a fundamental understanding of the operation of the device. A one-dimensional thermal resistance model (TRM) is utilized in modeling the evaporator. The paper presents a detailed discussion on obtaining these resistances from experiments conducted on the device. A correlation for the external heat transfer coefficient of the heat exchanger loop is proposed based on experiments and is found to be in good agreement with literature. The model predicts performance parameters such as board temperature, two-phase mixture quality, and saturation and subcooled temperatures (Tsat and Tsc) of the working fluid for different input thermal powers (Qtot). Based on experimental evidence, it is concluded that the majority of Qtot (∼75%) is utilized in phase change of the working fluid, and the rest reheats the working fluid from a lower subcooled temperature (Tsc) to the saturation temperature (Tsat) of the evaporator.

Effects of Varying Geometrical Parameters on Boiling From Microfabricated Enhanced Structures

2003 ◽  
Vol 125 (1) ◽  
pp. 103-109 ◽  
Author(s):  
C. Ramaswamy ◽  
Y. Joshi ◽  
W. Nakayama ◽  
W. B. Johnson
Keyword(s):  
Heat Dissipation ◽  
Layer Structure ◽  
Single Layer ◽  
Nucleate Boiling ◽  
Heat Fluxes ◽  
Working Fluid ◽  
Geometrical Parameters ◽  
Small Range ◽  
Two Phase ◽  
Wall Superheat

The current study involves two-phase cooling from enhanced structures whose dimensions have been changed systematically using microfabrication techniques. The aim is to optimize the dimensions to maximize the heat transfer. The enhanced structure used in this study consists of a stacked network of interconnecting channels making it highly porous. The effect of varying the pore size, pitch and height on the boiling performance was studied, with fluorocarbon FC-72 as the working fluid. While most of the previous studies on the mechanism of enhanced nucleate boiling have focused on a small range of wall superheats (0–4 K), the present study covers a wider range (as high as 30 K). A larger pore and smaller pitch resulted in higher heat dissipation at all heat fluxes. The effect of stacking multiple layers showed a proportional increase in heat dissipation (with additional layers) in a certain range of wall superheat values only. In the wall superheat range 8–13 K, no appreciable difference was observed between a single layer structure and a three layer structure. A fin effect combined with change in the boiling phenomenon within the sub-surface layers is proposed to explain this effect.

Sign in / Sign up

Export Citation Format

Share Document