Dongqiang Lei

The Glass-To-Metal Sealing Process in Parabolic Trough Solar Receivers

This paper introduces the structure and components of the receiver tube (HCE) in the parabolic trough solar thermal power system, and presents the technologic difficulty of achieving good glass-to-metal sealing during the process of receiver tube manufacture. The glass-to-metal sealing of HCE failure /degradation is the single largest cost factor in the 9 parabolic trough solar power plants in the USA, which also results in the system efficiency reduction. The article also elaborates the principle of glass-to-metal sealing and various demands on material for the sake of fine sealing. Aiming to the current technique practice of Kovar-to-glass sealing, technological process and optimal processing parameters are put forward based on research and experiments.

The study of one-through solar absorber receiver

This paper introduces the configuration and components of a solar absorber receiver in the parabolic trough solar power system. The failure or degradation of the receiver, mainly including glass-to-metal sealing failure, loss of vacuum and degradation of solar selective coating, is the single largest cost factor for current and future solar power plant. The article elaborates the principle of glass-to-metal sealing and a new glass-to-metal seal technology that has been developed through a lot of experiments. The tensile tests and EPMA tests have proven the high reliability and strength of the glass-to-metal seals. The vacuum seal of glass-metal joint is tested using a helium mass spectrometer leak detector. The paper also introduces a new solar selective coating and getters used in the receiver. A process of glass to metal sealing is developed and the prototypes of solar absorber receiver are manufactured.

Performance and durability testing of parabolic trough receivers

The paper describes the key performance and durability testing facilities of the parabolic trough receiver developed by Institute of Electrical Engineering, Chinese Academy of Sciences. The indoor heat loss test can be applied at 4-7 different temperature levels within 200-550 on receivers. The optical efficiency test bench consists of 12 metal halide lamps as the solar simulator and a 5 m length half-elliptical cylinder reflector with flat end reflectors. 3 ultra-precision temperature sensors are used in receiver each end to get the temperature difference. The residual gas analysis test bench is applied to analyze and predict the vacuum lifetime of the receiver. It can test the variations of composition and partial pressure of residual gases with temperature and time in the receiver annulus space by a high sensitivity quadrupole mass spectrometer gas analyzer. A coating accelerated ageing test bench, which is also used to test the thermal cycle, has been developed. This test bench uses the absorber tube ...