High Rotating Tester Development For Super- Critical Flow Heat Transfer

Hydrocarbon fuels may easily occur a series of chemical reactions in super-critical environment. The precipitate produced by the reactions will be adhered to the pipe wall and increasingly accumulate, which may cause disastrous consequences. Besides, the heat transfer process of fluid in rotating pipe is quite complicated, due to the influence of centrifugal force and Coriolis force. Hence the study on fuel system and performance is essential. Commissioned by the Institute of thermal physics of the thermal engineering department, Tsinghua University, a test bench is designed and developed to investigate the heat transfer property of super-critical fluid in rotating state. The mainly completed work in this article follows.(1) Structural design of the test bench. The maximum design speed of rotor is 3300 r/min, which is driven and speed up by synchronous belt wheel. The maximum outlet pressure of the rotating high-temperature pipe system reaches 6 MPa and outlet temperature reaches 500 ℃. The test pipelines consist of three segments:centrifugal, horizontal and radial segments. Almost 20 points for temperature measurement are fixed on each segment of pipeline.(2) Automatic control system design. The control system of test bench utilizes typical master-computer and slave device control mode. The Siemens S7-200 PLC is utilized as the core controller. The DAQ system which acquisition, display and save the whole test data is designed to be independent to the bench.(3) The local heating technique on rotating slender pipe is implemented by the short circuit heating method. Meanwhile, measurement of the surface temperature of rotating conductor and data transform between static and dynamic is implemented in this article.The test bench developed in this article solves several technical difficulties on test research for heat transfer of liquid fluid in rotating state. The performance verification test for the test bench has been conducted successfully. The test results indicated that the bench could satisfy the test requirements and record test data effectively. The mechanical structure and control system of the tester has a high stability and reliability, fully meet the design requirements.