| 摘要 |
PURPOSE:To increase the total heat recovery quantity by a method wherein heat balance between the heat exchanger and respective elements are calculated and feed flow rates to the respective elements are controlled so that the heat recovery efficiencies at the respective elements are settled within a fixed range at the heat exchanger employed in a heating furnace or the like. CONSTITUTION:A thermometer 7 is provided at a cold air duct 2 and a flow control valve 8 and a pressure gage 9 are provided at the supply duct 5 of each element 3 and a pressure- actuated thermometer 8 is provided at the discharge duct 6 of each element 3. An operational controlling unit 11 calculates the recovered heat quantity Q of the heat exchanger based upon temperature differences DELTATi between the thermometers 7 and 10 and pressure difference DELTAPi between the pressure gages 9 and 10. After that, mean heat recovery quantities of every respective element are calculated based upon the number of the elements N and the recovered heat quantity Q. Respective means heat recovery quantities of the element is compared with the heat recovery quantity DELTATi (DELTAPi)<1/2> of every respective element and, if the value (q) is larger than the value DELTATi(DELTAPi)<1/2>, the control valve 8 of subject element is put into operation in order to open, while if the value (q) is smaller than the value DELTATi(DELTAPi)<1/2>, the control valve 8 of subject element is put into operation in order to close. The operational control as just mentioned above is performed once every 20-30min. Accordingly, the flow coefficient and discharge duct temperature of the respective elements are uniformized, resulting in increasing the total heat recovery quantity. |
