【摘要】：海水鹽度是觀測海洋和研究海洋水文的主要因素之一。目前用海洋儀器測量海水鹽度,普遍采用相對測量法,即以一種物質(zhì)為標(biāo)準(zhǔn)。國家一級標(biāo)準(zhǔn)海水和系列標(biāo)準(zhǔn)海水為海水鹽度標(biāo)準(zhǔn)物質(zhì)。因天然海水鹽度較小,所以將天然海水制備成標(biāo)準(zhǔn)海水的首要過程就是進行海水濃縮。本文根據(jù)相關(guān)部門的需求設(shè)計了一套基于PLC的智能海水濃縮裝置。通過分析總結(jié)以往海水濃縮裝置對海水有污染,破壞海水成分,不耐腐蝕,壽命短,自動化程度低等缺點,確定了本課題裝置研究方向和設(shè)計目標(biāo)。按照要求,本課題設(shè)計的濃縮裝置必須實現(xiàn)海水低溫濃縮,即濃縮過程海水不得高于40℃。本裝置通過管路換熱的方式,對海水進行升溫加熱,不破壞海水成分,不污染海水。為加快低溫海水濃縮的速度,在冷凝玻璃上蓋處引入了制冷系統(tǒng),在海水槽內(nèi)形成溫場差。為保證冷凝玻璃上蓋低溫恒定,加入了變頻器控制壓縮機制冷的技術(shù)。壓縮機制冷過程中產(chǎn)生的熱量可以對海水進行加熱,達(dá)到了冷熱能能充分利用、節(jié)約能源的效果。隨著海水水分蒸發(fā),海水鹽度提高,達(dá)到設(shè)定鹽度,裝置自動停止運行。本課題控制系統(tǒng)以西門子S7-200 SMART系列PLC為主控單元,并擴展應(yīng)用了模擬量輸入、輸出模塊。采用模糊PID的控制策略和變頻控制技術(shù),對海水溫度和海水槽上蓋溫度進行精確控制。裝置引入了人機交互的觸摸屏界面,使操作方便,增強參數(shù)可觀測性。
[Abstract]:The salinity of sea water is one of the main factors for observing the ocean and studying the ocean hydrology. At present, the relative measurement method is generally used to measure the salinity of sea water with ocean instruments, that is to say, a kind of substance is used as the standard. National standard sea water and series standard sea water are salinities standard material of sea water. Because of the low salinity of natural sea water, the primary process of preparing natural seawater into standard sea water is sea water concentration. In this paper, a set of intelligent seawater concentration device based on PLC is designed according to the requirements of relevant departments. By analyzing and summarizing the disadvantages of seawater concentration devices in the past, such as pollution of seawater, destruction of seawater composition, non-corrosion resistance, short life and low degree of automation, the research direction and design target of this project are determined. According to the requirement, the concentrator designed in this paper must realize the low temperature concentration of sea water, that is, the sea water must not be higher than 40 鈩，

本文編號：2438297