A13 .Performance of a Stirling engine with dead volume positively added between the high temperature heat exchanger and the expansion piston

2011 ◽  
Vol 2011.14 (0) ◽  
pp. 85-86
Author(s):  
Yoshihiko HARAMURA
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Stirling Engine ◽  
Dead Volume ◽  
Temperature Heat

Performance of Novel High Temperature Heat Exchanger for 1 kW Class Stirling Engine Considering Heat Recovery

2016 ◽  
Vol 24 (01) ◽  
pp. 1650007 ◽  
Author(s):  
Joon Ahn ◽  
Seok Yeon Kim
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Thermodynamic Cycle ◽  
Stirling Engine ◽  
Head Part ◽  
Fixed Temperature ◽  
Fuel Gas ◽  
Temperature Heat ◽  
Cogeneration System ◽  
Heat Quantity

This research proposed a novel shape design by integrating the geometry that showed the best performance including fin length, pitch and angle on the high temperature heat exchanger of Stirling engine designed for the prime mover of 1kW cogeneration system for home. First, the numerical simulation was conducted on the new design and existing shape, and the performance improvement according to the shape optimization was checked. Next, the validity of its performance was verified by additionally considering the heat loss from the recuperation and low-temperature heat exchanger. As a result, when the high temperature heat exchanger is optimized, a great amount of heat quantity is absorbed from the fuel gas from the upstream part where negative heat flux occurred in the cylinder head part. This was judged to be because of the fixed temperature of the high-temperature part in the thermodynamic cycle. Thus, when researching the shape of the high-temperature heat exchanger, an optimized geometry can be obtained when combining cycle interpretation of system rather than interpreting independently.

Effect of lateral fin profiles on stress performance of internally finned tubes in a high temperature heat exchanger

2013 ◽  
Vol 50 (1) ◽  
pp. 886-895 ◽  
Author(s):  
Min Zeng ◽  
Ting Ma ◽  
Bengt Sundén ◽  
Mohamed B. Trabia ◽  
Qiuwang Wang
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Finned Tubes ◽  
Temperature Heat

Transient Analysis of a Ceramic High Temperature Heat Exchanger and Chemical Decomposer

2007 ◽  
Author(s):  
Valery Ponyavin ◽  
Taha Mohamed ◽  
Mohamed Trabia ◽  
Yitung Chen ◽  
Anthony E. Hechanova
Keyword(s):  
Steady State ◽  
High Temperature ◽  
Heat Exchanger ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Failure Criteria ◽  
Operating Conditions ◽  
Finite Element Software ◽  
Micro Channels ◽  
Temperature Heat

Ceramics are suitable for use in high temperature applications as well as corrosive environment. These characteristics were the reason behind selection silicone carbide for a high temperature heat exchanger and chemical decomposer, which is a part of the Sulphur-Iodine (SI) thermo-chemical cycle. The heat exchanger is expected to operate in the range of 950°C. The proposed design is manufactured using fused ceramic layers that allow creation of micro-channels with dimensions below one millimeter. A proper design of the heat exchanges requires considering possibilities of failure due to stresses under both steady state and transient conditions. Temperature gradients within the heat exchanger ceramic components induce thermal stresses that dominate other stresses. A three-dimensional computational model is developed to investigate the fluid flow, heat transfer and stresses in the decomposer. Temperature distribution in the solid is imported to finite element software and used with pressure loads for stress analysis. The stress results are used to calculate probability of failure based on Weibull failure criteria. Earlier analysis showed that stress results at steady state operating conditions are satisfactory. The focus of this paper is to consider stresses that are induced during transient scenarios. In particular, the cases of startup and shutdown of the heat exchanger are considered. The paper presents an evaluation of the stresses in these two cases.

scholarly journals Thermodynamic modelling and efficiency analysis of a class of real indirectly fired gas turbine cycles

2009 ◽  
Vol 13 (4) ◽  
pp. 41-48
Author(s):  
Zheshu Ma ◽  
Zhenhuan Zhu
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Waste Heat ◽  
Operational Parameters ◽  
Forecast Performance ◽  
Micro Gas Turbine ◽  
Temperature Heat

Indirectly or externally-fired gas-turbines (IFGT or EFGT) are novel technology under development for small and medium scale combined power and heat supplies in combination with micro gas turbine technologies mainly for the utilization of the waste heat from the turbine in a recuperative process and the possibility of burning biomass or 'dirty' fuel by employing a high temperature heat exchanger to avoid the combustion gases passing through the turbine. In this paper, by assuming that all fluid friction losses in the compressor and turbine are quantified by a corresponding isentropic efficiency and all global irreversibilities in the high temperature heat exchanger are taken into account by an effective efficiency, a one dimensional model including power output and cycle efficiency formulation is derived for a class of real IFGT cycles. To illustrate and analyze the effect of operational parameters on IFGT efficiency, detailed numerical analysis and figures are produced. The results summarized by figures show that IFGT cycles are most efficient under low compression ratio ranges (3.0-6.0) and fit for low power output circumstances integrating with micro gas turbine technology. The model derived can be used to analyze and forecast performance of real IFGT configurations.

Design of a Compact Ceramic High-Temperature Heat Exchanger and Chemical Decomposer for Hydrogen Production

2012 ◽  
Vol 33 (10) ◽  
pp. 853-870 ◽  
Author(s):  
Valery Ponyavin ◽  
Yitung Chen ◽  
Taha Mohamed ◽  
Mohamed Trabia ◽  
Anthony E. Hechanova ◽  
...  
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Hydrogen Production ◽  
Temperature Heat

Experimental Studies on Thermal Performance of a Pebble Bed High-Temperature Heat Exchanger

1985 ◽  
Vol 107 (3) ◽  
pp. 722-727 ◽  
Author(s):  
K. Yoshikawa ◽  
H. Kajiyama ◽  
T. Okamura ◽  
S. Kabashima ◽  
H. Yamasaki ◽  
...  
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Thermal Performance ◽  
Experimental Studies ◽  
Pebble Bed ◽  
Temperature Heat

scholarly journals Thermal Performance of a 2000.DEG.C. Class Cored-Brick Bed High-Temperature Heat Exchanger.

1996 ◽  
Vol 62 (604) ◽  
pp. 4248-4253
Author(s):  
Satoshi UEOKA ◽  
Kunio YOSHIKAWA ◽  
Suwat RAVEEVONGANOTHAI ◽  
Susumu SHIODA ◽  
Saburou IKEDA ◽  
...  
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Thermal Performance ◽  
Temperature Heat

Fluidized-Bed Heat Transfer Modeling for the Development of Particle/Supercritical-CO2 Heat Exchanger

2017 ◽  
Author(s):  
Zhiwen Ma ◽  
Janna Martinek
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Heat Exchanger ◽  
Fluidized Bed ◽  
Solid Particles ◽  
Heat Transfer Modeling ◽  
Power Cycle ◽  
Heat Exchanger Design ◽  
Temperature Heat ◽  
The Cost

Concentrating solar power (CSP) technology is moving toward high-temperature and high-performance design. One technology approach is to explore high-temperature heat-transfer fluids and storage, integrated with a high-efficiency power cycle such as the supercritical carbon dioxide (s-CO2) Brayton power cycle. The s-CO2 Brayton power system has great potential to enable the future CSP system to achieve high solar-to-electricity conversion efficiency and to reduce the cost of power generation. Solid particles have been proposed as a possible high-temperature heat-transfer medium that is inexpensive and stable at high temperatures above 1,000°C. The particle/heat exchanger provides a connection between the particles and s-CO2 fluid in the emerging s-CO2 power cycles in order to meet CSP power-cycle performance targets of 50% thermal-to-electric efficiency, and dry cooling at an ambient temperature of 40°C. The development goals for a particle/s-CO2 heat exchanger are to heat s-CO2 to ≥720°C and to use direct thermal storage with low-cost, stable solid particles. This paper presents heat-transfer modeling to inform the particle/s-CO2 heat-exchanger design and assess design tradeoffs. The heat-transfer process was modeled based on a particle/s-CO2 counterflow configuration. Empirical heat-transfer correlations for the fluidized bed and s-CO2 were used in calculating the heat-transfer area and optimizing the tube layout. A 2-D computational fluid-dynamics simulation was applied for particle distribution and fluidization characterization. The operating conditions were studied from the heat-transfer analysis, and cost was estimated from the sizing of the heat exchanger. The paper shows the path in achieving the cost and performance objectives for a heat-exchanger design.

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