Thermal performance and flow characteristics of two-phase loop thermosyphons

2020 ◽  
Vol 77 (7) ◽  
pp. 683-701
Author(s):  
Sara Kloczko ◽  
Amir Faghri
Keyword(s):  
Thermal Performance ◽  
Flow Characteristics ◽  
Two Phase ◽  
Phase Loop

Development of Analysis Algorithm and Computational Methodology for the Evaluation of Non-Uniform Energy Conversion System Performance: Part I — Component Analysis Modules

2006 ◽  
Author(s):  
Casey Loughrin ◽  
Hyunjae Park ◽  
Robert Weber
Keyword(s):  
Energy Conversion ◽  
Thermal Performance ◽  
System Performance ◽  
Flow Characteristics ◽  
Heating System ◽  
Component Analysis ◽  
Connectivity Matrix ◽  
Two Phase ◽  
Energy Conversion Systems ◽  
The Individual

This paper examines the development of the individual component analysis modules applied to two selected energy conversion systems; a vapor-compression refrigeration system and a boiler heating system. The energy conversion components used in this work are the evaporator, condenser, expansion valve, mixing chamber, open feedwater heater, pipe, boiler, pump, and compressor. The developed component analysis modules are able to apply input data and specifications to estimate the corresponding thermal performance of the component. Upon investigation of the two case studies presented, it was found that the two-phase heat exchanging components such as the evaporator, condenser and boiler were the primary sources of the non-uniform system performance characteristics. As a consequence, a system connectivity matrix has been developed to evaluate the mass and energy flow characteristics of working fluids between components. The developed component analysis modules, in conjunction with the system connectivity matrix, were exclusively used to calculate the local and overall system thermal performance.

Multi-Nozzle Spray Cooling in a Closed Loop

2011 ◽  
Author(s):  
Lanchao Lin ◽  
Quinn Leland
Keyword(s):  
Thermal Performance ◽  
Closed Loop ◽  
Target Surface ◽  
Spray Cooling ◽  
High Heat ◽  
High Heat Flux ◽  
Gear Pump ◽  
Two Phase ◽  
Power Sources ◽  
Phase Loop

A closed two-phase loop system was developed that combined with a multi-nozzle spray cooling unit for the cooling of high heat flux power sources. The fluid circulation was sustained by a magnetic gear pump operating with an ejector pump unit. The motive flow of the ejector shared the pumping liquid flow with the multi-nozzle spray. The use of the ejector stabilized the circulation of the two-phase flow. A multi-nozzle plate with 48 miniature nozzles was designed to generate an array of 4×12 sprays. A closed loop spray cooling experimental setup with a cooling area of 19.3 cm2 was built. The spray nozzle to target distance was 10 mm. Water and FC-72 were used as the working fluids. Spray cooling experiments were performed in three orientations of the spray target surface, namely (a) horizontal facing upward, (b) vertical, and (c) horizontal facing downward. The thermal performance of the horizontal facing downward surface was the best. A comparison with the thermal performance data for a smaller cooling surface area of 2.0 cm2 was made.

An Experimental Study of Thermal Performance of a Two-Phase Loop Thermosyphon (TPLT)-Based Steam Generator: Effects of Thermal Boundary Conditions

2013 ◽  
Author(s):  
Meng Hua ◽  
Liang Zhang ◽  
Zi-Qin Zhu ◽  
Li-Wu Fan ◽  
Zi-Tao Yu ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Thermal Performance ◽  
Flow Instability ◽  
Natural Circulation ◽  
Filling Ratio ◽  
Two Phase ◽  
Thermal Boundary Conditions ◽  
Heating Section ◽  
Phase Loop ◽  
Ratio Condition

For the Parabolic trough collector (PTC) system, thermal boundary condition of the receiver (or heating section) is important for the thermal optimization. In this work, effects of thermal boundary on thermal performance of the two-phase loop thermosyphon (TPLT) natural circulation PTC system was investigated experimentally. Three kinds of thermal boundary heating conditions (upper and lower half, and whole circular heated) and two filling ratios (FR = 0.6, 1.2) were adopted in this paper. The results show that half heating condition can improve heat transfer performance in receiver and system thermal resistance. But the preferred half heating boundary was varied as the filling ratio was changed. However, a lower thermal efficiency was observed for the partly heating boundary conditions. For a low heat flux condition in this work, the effects of thermal boundary on flow instability were not obvious, especially for the bigger filling ratio condition.

Thermal performance of a R600a two-phase loop thermosiphon in rotational shaft

2021 ◽  
Author(s):  
Fajing Li ◽  
Jianmin Gao ◽  
Xiaojun Shi ◽  
Feng Liang ◽  
Daoyong Wang
Keyword(s):  
Thermal Performance ◽  
Two Phase ◽  
Phase Loop

Development of Analysis Algorithm and Computational Methodology for the Evaluation of Non-Uniform Energy Conversion System Performance: Part II — System Connectivity

2006 ◽  
Author(s):  
Casey Loughrin ◽  
Hyunjae Park ◽  
Robert Weber
Keyword(s):  
Energy Conversion ◽  
Thermal Performance ◽  
System Performance ◽  
Flow Characteristics ◽  
Component Analysis ◽  
Connectivity Matrix ◽  
Convergence Criteria ◽  
Two Phase ◽  
Analysis Algorithm ◽  
Computational Methodology

It has been proposed to develop a component analysis module for each energy and heat exchanging component in a system. A system connectivity matrix has been developed to evaluate the mass and energy flow characteristics between components and the system performance. The developed component analysis modules, in conjunction with the system connectivity matrix, are exclusively used to calculate the overall and local system thermal performance. In this work, two sample energy conversion systems were selected; a vaporcompression refrigeration system and a boiler heating system. This paper examines the development of the system connectivity matrices and the corresponding iterative and/or non-iterative analysis algorithm and computational methodology. Proper mass and energy balances are formed based on the structure of the system connectivity matrix along with appropriate thermodynamic property models. The balance equations are then solved iteratively by using the developed component analysis modules until the residuals meet the convergence criteria. It was found that for the selected two systems the variations in thermal effectiveness of the two-phase heat and energy exchanging components, such as the evaporator, condenser and boiler in this work, were the main contributor of non-uniform system thermal performance.

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