溫度較低的冷卻水由換熱器下部進(jìn)入換熱器，與循環(huán)空氣換熱后，由換熱器上部流出。被加熱后的冷卻水流至冷卻塔等冷卻設(shè)備進(jìn)行冷卻，經(jīng)冷卻降溫的冷卻水經(jīng)水泵再次進(jìn)入換熱器對循環(huán)空氣進(jìn)行冷卻，如此循環(huán)。
圖5 水路循環(huán)
5.電控系統(tǒng)組成
系統(tǒng)由整流變壓器、功率單元柜、水冷控制系統(tǒng)、PLC控制柜、工控機(jī)、監(jiān)控畫面組成。PLC柜主要采集變頻器的開關(guān)量信號(hào)、模擬量信號(hào)，開關(guān)柜的電能信號(hào)、水冷控制系統(tǒng)的流量、溫度等信號(hào)，通過監(jiān)控畫面顯示并達(dá)到遠(yuǎn)程控制目的。系統(tǒng)框圖如下：
圖6 電控系統(tǒng)框圖
變頻器主控PLC控制總的調(diào)速任務(wù)，包括變頻器的調(diào)速控制及與機(jī)組邏輯控制PLC系統(tǒng)（西門子416系統(tǒng)）的通訊。變頻裝置與機(jī)組邏輯控制PLC系統(tǒng)采用點(diǎn)對點(diǎn)的通訊方式。變頻器主控PLC可接收機(jī)組邏輯控制PLC系統(tǒng)的中控指令、中控投入、中控解除、變頻投入、變頻不投入、停止加速、機(jī)組預(yù)放電等；變頻器主控PLC發(fā)給機(jī)組邏輯控制PLC系統(tǒng)的信號(hào)有：機(jī)組加速中，機(jī)組加速到位、動(dòng)態(tài)回令（機(jī)組預(yù)防電條件滿足）、變頻器事故綜合、滑差提電極到預(yù)定位、靜態(tài)回令、機(jī)組加速，接受滑差PLC的電極位置（預(yù)定位、低位、高位）、速度到達(dá)等信號(hào)。
6.上位控制系統(tǒng)
項(xiàng)目中上位機(jī)監(jiān)控系統(tǒng)，選用工控機(jī)與PLC進(jìn)行網(wǎng)絡(luò)通訊；利用WINCC組態(tài)監(jiān)控軟件，實(shí)現(xiàn)實(shí)時(shí)多畫面監(jiān)控，以達(dá)到監(jiān)控設(shè)備運(yùn)行狀態(tài)的目的。監(jiān)控畫面主要包括：主界面、報(bào)警歸檔頁面、數(shù)據(jù)歸檔頁面、3個(gè)機(jī)組頁面、以及各個(gè)變頻器的數(shù)據(jù)曲線頁面等。
圖7 西南核工業(yè)上位監(jiān)控系統(tǒng)
1.變頻器與PLC控制系統(tǒng)通訊：變頻器與PLC控制系統(tǒng)之間物理通訊為485通訊，通訊協(xié)議為Modbus/RTU協(xié)議，可選Profibus協(xié)議。
2.自動(dòng)控制系統(tǒng)：設(shè)備監(jiān)控核心采用西門子S7系列可編程控制器，結(jié)合現(xiàn)場傳感器和設(shè)備控制接口實(shí)現(xiàn)電機(jī)及附屬設(shè)備的邏輯控制和運(yùn)行狀態(tài)、參數(shù)的實(shí)時(shí)在線監(jiān)測，并采用PLC冗余系統(tǒng)，自動(dòng)切換。PLC系統(tǒng)實(shí)時(shí)采集高壓變頻器的運(yùn)行狀態(tài)，并實(shí)時(shí)控制變頻器運(yùn)行。
3.在線監(jiān)控系統(tǒng)：采用大屏幕真彩液晶顯示器；按照雙機(jī)冗余互為備用模式設(shè)計(jì)，置專業(yè)工業(yè)控制組態(tài)軟件實(shí)時(shí)顯示運(yùn)行工況參數(shù)，動(dòng)態(tài)顯示工藝流程圖形和設(shè)備運(yùn)行狀態(tài)。 and the memory of s7-1200 is also slightly insufficient.
In addition, there are not many HMI supporting S7 1200, and there are few options.
(reflow) refers to the paste soft paste pre distributed to the printed board pad by remelting
To realize the soft soldering of mechanical and electrical connection between the welding end or pin of surface assembled components and the bonding pad of printed board. It provides a heating environment to heat and melt the solder paste, so as to make the surface mount components and
B pad through solder paste
According to the technical characteristics of reflow welding, the equipment reliably combined together can be divided into gas-phase reflow, infrared reflow and hot air reflow. At present, the mainstream equipment adopts hot air reflow. Hot air reflow is to make the colloidal flux (solder paste) physically react under a certain high-temperature air flow to achieve SMD welding. Because this hot air flow circulates inside the welding machine to achieve the purpose of welding, so, In the industry, the equipment that uses the original principle of thermal reflow to realize the
