On May 16, Hebei Cangdong Power Plant passed the technical acceptance of the research project of cascade utilization of seawater desalination extraction steam under full working conditions of thermal power units. The project overcame the problem of unstable operation of the seawater desalination device under deep peak-shaving conditions, and successfully explored the optimal way to match the operation of the thermal distillation seawater desalination device with the thermal power unit, filling the gap in the industry.
Cangdong Power Plant has built four low-temperature multi-effect distillation seawater desalination devices, with a total water production capacity of 57,500 tonnes/day, external water supply of more than 30,000 tonnes/day, water supply users covering port logistics, energy and chemical industry, grain and oil processing and other industries. In recent years, the coal-fired power units in deep peak-shaving conditions have continuously reduced loads, and the corresponding extraction steam pressure has also decreased, seriously restricting the efficiency of the desalination unit’s water production under low-load working conditions.
To address the problem and realize the efficient cascade utilization of the residual pressure of the extraction steam, thereby improving the water production capacity of the existing thermal distillation desalination to adapt to the low parameter steam, the Plant innovatively put forward the 25,000 tonnes/day thermal desalination back pressure turbine + MED technical solutions to ensure the stable operation of the desalination equipment under the deep peak-shaving working conditions of the generator unit, reduce the cost of water production, and increase the unit’s capability of cascade utilization of the extraction steam and the economic efficiency of the desalination device operation.
