Research on thermodynamic calculation correction method for phase adjustment and pressure water process of pump turbine

During the process of phase regulation and pressurized water supply, the fluid temperature inside the gas supply system of the pumped storage power station&s;s water pump turbine unit undergoes significant changes. The drastic changes in temperature will have a certain impact on the strength of equipment and pipelines, posing safety hazards during operation. During the design process, the volume of the gas storage tank is estimated and selected based on relevant standards and specifications. The fluid temperature inside the gas storage tank after pressurized water is calculated through thermodynamic theory. During the calculation process, the correlation coefficients were taken based on empirical values, and certain assumptions were made about the water pressure process and gas state, resulting in low accuracy of the final temperature values. This article is based on on-site measured data and converts the internal fluid temperature distribution of the system through heat transfer formulas. The measured data is used to correct the thermodynamic theoretical calculation of the pressurized water supply process, and the gas volume and correlation coefficient values are derived. The gas volume obtained based on measured data and the further selection of gas storage tank volume reasonably consider the influence of temperature, which can reflect the actual operation of the unit. The proposed correlation coefficient value is also an exploratory study of theoretical design values and can provide reference for the design of other similar power plants.