| 摘要 |
PURPOSE:To save power in a cooling water flow rate control system of the condenser in a power plant by a method wherein openings of the bypass valve of the condenser are regulated by using signals of an opening control circuit in a circulating water pumps when the flow rate of the cooling water running in the condenser exceeds a rating one. CONSTITUTION:While cooling water beyond inlet valves 4A, 4B of the condenser 7 passes in arrow direction X, Y through a nest of cooling tubes in the condenser 7 in a cooling water system of the condenser 7, the cooling water exchanges heat with the exhaust of a steam turbine 8 and the exhaust is cooled and liquefied. At this time, in proportion to the deviation Q3 obtained by adding 102 a flow rate presetting value Q1 from a flow rate presetting circuit 101 to a total, actual flow rate Q2 from a flow rate detector 12A, a total flow rate command value Q4 from a flow rate command circuit 103 is given to a blade opening converter 104 and the blade opening of the circulating water pump 2A is controlled by that output on the basis of a feed-back value. When the command value Q4 exceeds a flow rate limit value on the condenser 7 part, the increment Q5 is outputted from a bypass valve flow rate presetting circuit 107 to open the bypass valve 10A. |
