Study on circulating cooling water pre-mixing for thermal performance improvement of twin thermal power units sharing one dry cooling tower

For an advanced power plant of twin thermal power units sharing one dry cooling tower, power production is easily impacted by variations in cooling tower performance. Circulating cooling water pre-mixing (CCWPM) was proposed to maximize cooling potential of the tower under varying working conditions, thereby enhancing power generation for the whole power plant. An integrated simulation model was established to capture cooling behaviors of the shared tower and operating characteristics of both power units before and after implementing CCWPM. Simulation results indicated that CCWPM effectively mitigates the uneven distribution of airflow temperature inside the shared tower and reduces the high-temperature area. As power load of one specified unit drops, both units experience a decline in power cycle efficiency, and the implementation of CCWPM further decreases the efficiency of this unit while increasing the efficiency of the adjacent unit. The whole power plant benefits from CCWPM in power generation, particularly when the unit with radiators directly facing the crosswind operates at a low power load. Power generation efficiency achieves an absolute increase of 0.43 % via CCWPM for the upwind unit and its adjacent unit operating at 40 % and 100 % power loads and the shared tower working at 8 m/s crosswind speed.