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The feed water control system maintains the boiler drum level within permissible limits, by regulating the feed water flow to match the steam generation rate. During startup and low load operation, a single element controller using drum level signal is used for regulating the feed water flow. The drum level signal is compared with the startup set value signal and controller output modulates the M-BFP flow control valve to increase or decrease feed water flow as desired. M-BFP hydraulic scoop control maintains a pressure (drum pressure +α), which is a function of drum pressure and main steam flow, at the inlet of the control valve for smooth control. When the main steam flow reaches 550t/hr, feed water flow control transfers to 3 element control system (steam flow, feed water flow and drum level) configured in cascade mode. While the M-BFP is in operation, the T-BFP is started and run up to speed and kept ready to takeover feed water control when feed water flow reaches about 25% MCR. When the T-BFP discharge is equal to the feed water header pressure, the T-BFP discharge valve is opened. As the BFPT speed is increased, the T-BFP starts feeding water to drum and automatically, the

The Feed Water Control System Maintains the Boiler Drum Level Within Permissible

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The feed water control system maintains the boiler drum level within permissible limits, by regulating the feed water flow to match the steam generation rate. During startup and low load operation, a single element controller using drum level signal is used for regulating the feed water flow. The drum level signal is compared with the startup set value signal and controller output modulates the M-BFP flow control valve to increase or decrease feed water flow as desired. M-BFP hydraulic scoop control maintains a pressure (drum pressure +), which is a function of drum pressure and main steam flow, at the inlet of the control valve for smooth control. When the main steam flow reaches 550t/hr, feed water flow control transfers to 3 element control system (steam flow, feed water flow and drum level) configured in cascade mode. While the M-BFP is in operation, the T-BFP is started and run up to speed and kept ready to takeover feed water control when feed water flow reaches about 25% MCR. When the T-BFP discharge is equal to the feed water header pressure, the T-BFP discharge valve is opened. As the BFPT speed is increased, the T-BFP starts feeding water to drum and automatically, the M-BFP controller reduces the M-BFP scoop control, thus transferring the control to T-BFP. Further load up is then carried out to 50% MCR with one T-BFP in service. When the unit load reaches 50% MCR, the second T-BFP is also taken into service by opening its discharge valve. The two T-BFP share the load equally as the load is increased to 100%. During load down, one T-BFP is stopped as the unit load reduces to 50% ECR. The T-BFP to M-BFP transfer is carried out as the load reaches 25% MCR. The M-BFP is stopped after the boiler is shut down

Sistem kontrol air umpan mempertahankan tingkat boiler drum yang dalam diizinkanbatas, dengan mengatur aliran air umpan untuk mencocokkan tingkat generasi uap.Selama startup dan operasi beban rendah, controller elemen tunggal menggunakan gendangsinyal tingkat digunakan untuk mengatur aliran air umpan. Sinyal Tingkat drumdibandingkan dengan startup mengatur sinyal nilai dan pengendali keluaran memodulasiM-BFP kontrol aliran katup untuk meningkatkan atau menurunkan aliran air umpan yang diinginkan.M-BFP control sendok hidrolik mempertahankan tekanan (pressure Drum + ),yang merupakan fungsi dari tekanan gendang dan aliran uap utama, di inlet darikatup kontrol untuk kontrol halus.Ketika aliran uap utama mencapai 550T / jam, makan air transfer kontrol aliran untukSistem 3 elemen kontrol (aliran uap, aliran air umpan dan tingkat Drum)dikonfigurasi dalam mode cascade.Sementara M-BFP dalam operasi, T-BFP dimulai dan dijalankan sampai dengan kecepatan danterus siap untuk pengambilalihan kendali air umpan saat aliran air umpan mencapai sekitar25% MCR. Ketika debit T-BFP sama dengan header air umpantekanan, katup discharge T-BFP dibuka. Sebagai kecepatan BFPT adalahmeningkat, T-BFP mulai makan air untuk menghidupkan dan otomatis, yangM-BFP kontroler mengurangi kontrol sendok M-BFP, sehingga mentransfer kontroluntuk T-BFP. Selanjutnya memuat kemudian dilakukan untuk 50% MCR dengan satu T-BFP dilayanan. Ketika beban unit mencapai 50% MCR, kedua T-BFP juga diambilke layanan dengan membuka katup pembuangan nya. Dua T-BFP berbagi bebansama seperti beban meningkat sampai 100%.Selama down load, satu T-BFP dihentikan sebagai beban unit mengurangi 50% ECR.T-BFP transfer M-BFP dilakukan sebagai beban mencapai 25% MCR. ItuM-BFP dihentikan setelah boiler dimatikan