Repozytorium publikacji - Politechnika Gdańska

An analytical model of direct steam condensation (DCC) in the novel idea of spray ejector condenser (SEC) in the presence of inert gas has been developed. It is based on continuity, momentum and energy equations for the steam-carbon dioxide mixture and direct contact condensation mechanisms due to heat transfer and concentration. Crucial in the process of DCC is atomisation of the motive fluid in the ejector. The effect of atomised droplet size is exhibiting a significant amplification influence with increasing size of the droplet. Motive fluid is driving the secondary fluid-mixture of steam and inert gas in the Venturi nozzle and is cold enough to cause direct condensation. The intensity of heat transfer process from steam to water when the phases are in direct contact is much higher than the heat transfer intensity in surface heat exchangers. The analytical model pertains to a subcritical flow of a mixture of steam and gas in SEC. The model exhibits satisfactory agreement with experimental data. The model of DCC predicts higher values of temperature drop between inlet and outlet from the mixing section for the case of smaller steam-CO2 flow rates. Increasing the flow rate of steam mixture from 1.2 g/s to 3.6 g/s results in a reduction of steam mixture temperature from 25 ◦C to 14 ◦C respectively, at CO2 flow rate of 6.8 m3 /h. Condensation without presence of CO2 in the same range of steam flow rate, i.e. from 1.2 g/s to 3.6 g/s results in reduction of steam mixture temperature from 56 ◦C to 25 ◦C respectively, confirming in such way the effect of CO2 presence on the efficiency of DCC. Such model allow for discussion of parameters affecting process of condensation in SEC and ability of application such condenser in power plants.

Autorzy

• prof. dr hab. inż. Dariusz Mikielewicz link otwiera się w nowej karcie ,
• mgr Milad Amiri link otwiera się w nowej karcie ,
• dr hab. inż. Michał Klugmann link otwiera się w nowej karcie ,
• Prof Jaroslaw Mikielewicz