Comprehensive study of the operational reliability of the power plant impeller of the turbo-expander type from structural plastic

The relevance of the problem under research is conditioned by the necessity to study new, cheaper and advanced structural materials used in modern, highly economical equipment for the Russian gas industry. This article is focused on the reliability evaluation of the new structural materials (modern plastics) and new design decisions corresponding to them for creating turbine stages of gas transmission stations' turbo-expanders. The leading method of this problem study is the computational one. The article provides the strength computation results of the turbo-expander impeller at the moment immediately preceding its destruction. The paper contains also the experimental part with the recording and description of the actual destruction of the turbo-expander's impeller from the real plastic. The main results of the article are as follows: - creating the strength computing model of the turbo-expander's plastic impeller (up to the moment of its destruction) in the modern ANSYS software packages; - based on a comparison of the plastic impeller stress calculation with the picture of its destruction, it has been concluded that the indicated computing model is consistent; - evaluation of the new acoustic method for determining the turbo-expander's impeller rotation rate which may be recommended as a primary or stand-by one, both in 'On Line' and 'Off Line' mode. The article materials can be useful for professionals involved in the design of various turbo machines with plastic elements manufactured by a modern, non-waste, and environmentallyfriendly method using 3D printers. The article materials can also be useful for specialists in the field of turbomachines operations in organizations involved in the transport and use of natural gas. Keywords : turbomachines high-speed stage; strain-stress state of the turbomechines impellers; nature of the plastic impeller destruction; condition of the impeller securing on the turbine plant shaft; practical implementation of the turbine rotor rotation rate acoustic measurements method; stresses concentration effects in the impeller at low gas temperature.