Thermal Performance of a Two-Phase Loop Thermosyphon with an Additively Manufactured Evaporator

Multi-Nozzle Spray Cooling in a Closed Loop

ASME/JSME 2011 8th Thermal Engineering Joint Conference ◽

10.1115/ajtec2011-44597 ◽

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.

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

Volume 1: Heat Transfer in Energy Systems; Thermophysical Properties; Theory and Fundamental Research in Heat Transfer ◽

10.1115/ht2013-17104 ◽

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.

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