EXPERIMENTAL STAGES FOR COMPRESSED-GAS TURBINES

摘要

A traditional problem in experiments on compressed-gas turbines lies in choosing the working stage and correspondingly the low-temperature test system, which substantially simulates the refrigeration unit, or else a model for an air stage at normal temperature with a simple warm tester. The air model is constructed from the working parameters on the basis of preserving the working stage geometry. In a cold tester, the experiments are usually restricted to recording external characteristics, namely the working parameters at inlet and outlet and the rotational speed. The sole intervention in the working process is to measure the pressure in the gap between the guide blades and the rotor, which serves to define an important internal characteristic, namely the degree of reactivity. In that respect, the scope for a warm tester is much greater, quite apart from the simplicity, flexibility, and low working costs. However, one advantage of a cold tester is obvious: one can check out the design and the mechanical part of the unit (apertures, deviation from coaxial structure, tilts, thermal bridges, and so on) under low-temperature working conditions. If the equipment design has been finalized and repeatedly checked, it is not essential to perform extensive and cumbersome experiments on a cold tester.