Institute of Fluid-Flow Machinery
Polish Academy of Sciences

As part of the statutory work and the key project, work was carried out on issues related to the development of concepts, analysis of working factors and parameters of circulation, and analysis of the structural solutions of the basic components of the CHP steam power plant working in Rankine's circulation for low boiling agent [I/4, I/5, I/6, I/7, I/15, I/16, I/17, I/18].

Work on the generalization of circulation with natural circulation assisted by forced mini-pump in which there is a condenser, evaporator and mini-pump was continued in the micro-pump, while there is no expansion compared to the micro-pump circuit. In such a circulation, the natural circulation of the agent is caused by the thermal density gradients of the agent, which is assisted by forcing using a mini-pump. The agent may be in liquid state or subject to phase transformation in the circulation loop. An analysis of heat exchange and fluid movement in the biphasic thermosifon model with an incomplete evaporation for vertical heating and cooling spaced on the upper horizontal circulatory circuit has been performed. The analysis of fluid movement and heat exchange is based on a stationary and one-dimensional model. A two-phase fluid flow is described using a separated model of biphasic fluid. The 2003 El-Hajal correlation was used to calculate the void fraction. The magnitude of friction losses during the flow of a biphasic R11 in adiabatic sections was determined by Zhang-Webb's correlation (2003), while for non-adiabatic sections according to Tran's correlation (2000). Mini-rotation pump was used to aid natural circulation of the agent in the minisifon. Numerical calculations have been made to determine the mass speed distribution of the reduced two-phase factor as a function of the density of the heat stream supplied into circulation for both variants [I/8]. In addition, the value of the heat transfer factor for boiling in the flow for mini-minicans was determined according to the generalized correlation of J. Mikielewicz (2007) [I/12] and Saitoh;a (2007) [I/11]. In addition, a distribution of the heat take-over rate for condensation in flow for mini-minicans was obtained according to Mikielewicz's generalised correlation (2007) [I/8] and Shah'a (1979) [I/10].