Open AccessA method of fast quality control inspection of loop heat pipe
Author(s) -
BinJuine Huang,
HurngWern Huang,
Tzu-Chen Liang,
Penghui Yang,
S.S. Hu
Publication year - 2021
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/1139/1/012004
Subject(s) - loop heat pipe , overshoot (microwave communication) , transient (computer programming) , failure mode and effects analysis , materials science , heat load , mode (computer interface) , heat pipe , loop (graph theory) , evaporator , transient response , mechanics , nuclear engineering , control theory (sociology) , structural engineering , engineering , composite material , heat transfer , mechanical engineering , thermodynamics , electrical engineering , computer science , physics , mathematics , heat exchanger , control (management) , combinatorics , artificial intelligence , operating system
The dynamic behaviour of loop heat pipe (LHP) changes with heat load and physical properties of LHP such as fluid charging, wick material, and tolerance in manufacture. The start-up phenomena of a LHP can be classified into four modes, according to the heat load Q in : failure mode, oscillating mode, overshoot mode, and normal mode. It is found that the operation mode is related to the rate of temperature rise in evaporator during initial transient performance using a step heating load. The abnormal high rate of temperature rise can be observed for LHP with failure, oscillating or overshoot mode performance. Based on this phenomenon, the normal-mode performance of LHP can be assured from a short transient test in about 80s using a step heat load, instead of using steady-state test (taking 1,800s). This transient test method has been applied in the quality inspection of commercial loop heat pipe in mass production. No LHP failure was found for more than 10 years for about 30,000 sets of street LED luminaires designed with LHP.