【正文】 時，冷卻塔風(fēng)機(jī)、冷卻水泵、冷凍水泵相應(yīng)啟動；時間至18:34分時，制冷主機(jī)自動開啟；整個中央空調(diào)機(jī)組啟動完成。圖329制冷系統(tǒng)啟停監(jiān)控效果圖通過運(yùn)用DDC數(shù)字控制器與CARE軟件對制冷系統(tǒng)啟停的監(jiān)控，大大的改善了報告廳中央空調(diào)機(jī)組啟停的人力投入和管理。A、 調(diào)節(jié)效率高，可以實現(xiàn)從0～50 Hz范圍內(nèi)的無級調(diào)速。B、 變頻器提供了豐富的輸入輸出信號端子；利用這些端子，可方便地實現(xiàn)電機(jī)的啟停、調(diào)速，再加上速度檢測回路，形成閉環(huán)控制，很容易實現(xiàn)自動化控制。C、 能同時實現(xiàn)軟啟動和軟停止。改造設(shè)備時，不涉及電動機(jī)及所驅(qū)動的風(fēng)機(jī)、泵本身，停機(jī)改造時間短。不限于電動機(jī)軸端或靠近處；方便處理。水泵變頻主要通過DDC數(shù)字系統(tǒng)、溫度傳感器、變頻器來進(jìn)行控制，溫度傳感器將檢測到的信號經(jīng)過變送器轉(zhuǎn)變?yōu)闃?biāo)準(zhǔn)的電信號。達(dá)到進(jìn)一步節(jié)能。同時可以檢修變頻器。B、變頻器主路和旁通各設(shè)一只主斷路器，同時兩者之間進(jìn)行電氣連鎖，防止主路和旁通同時投入工作。其中AO代表部件是冷卻水泵變頻器、冷凍水泵變頻器，AI代表部件是冷凍水回水溫度、冷卻水回水溫度及冷卻水供水溫度。如圖：圖352變頻屬性圖（3）.通過控制策略主要是對冷凍水泵跟冷凍回水溫度形成PID控制。當(dāng)中央空調(diào)機(jī)組剛開啟時，冷凍水泵全負(fù)荷運(yùn)轉(zhuǎn)；即50Hz；冷凍水回水溫度為12℃。如圖：圖353冷凍水泵變頻控制策略冷卻水泵跟冷卻水供水溫度、冷凍水供水溫度也形成PID控制，通過會回水溫度和供水溫度形成溫差；當(dāng)溫差大小等于5℃時，冷卻水泵全負(fù)荷運(yùn)行，即以50Hz的頻率運(yùn)轉(zhuǎn)。圖354冷卻水泵變頻控制策略（4）.當(dāng)屬性、原理圖及控制策略準(zhǔn)備完畢后，進(jìn)行軟件仿真模擬，通過預(yù)先設(shè)定好的條件，進(jìn)行冷凍水泵變頻。 圖355冷凍變頻仿真效果圖當(dāng)運(yùn)行一段時間之后，比如晚上19:00左右，冷凍水回水溫度是11℃時，水泵運(yùn)行頻率為40Hz。如圖：圖357冷卻水泵變頻仿真效果圖當(dāng)晚上19:00分左右，冷卻水回水溫度、供水溫度分別是36℃、32℃時，冷卻水泵變頻器開啟時的頻率40Hz,進(jìn)行運(yùn)轉(zhuǎn)。根據(jù)河源職業(yè)技術(shù)學(xué)院中央空調(diào)制冷系統(tǒng)點(diǎn)數(shù)統(tǒng)計表和水泵、風(fēng)機(jī)變頻點(diǎn)數(shù)統(tǒng)計表可以得出，共計使用DDCAI點(diǎn)數(shù)12個，DI點(diǎn)數(shù)12個，AO點(diǎn)數(shù)1個，DO點(diǎn)數(shù)12個。（1）Excel50有8個模擬輸入、4個模擬輸出、4個數(shù)字輸入及6個數(shù)字輸出。（3）采用不同的方式進(jìn)行通訊，比如通過XI58服務(wù)軟件或CBus均可進(jìn)行程序下載。選用霍尼韋爾系列AF20的溫度傳感器，其主要特性如下： （1）.溫度元件NTC20K。 （3）.盒體材料塑料(PCABS)。 （5）.防護(hù)等級IP30。%RH（0~100%RH非凝結(jié)）。（3）.熱固性聚合物電容傳感器，帶集成信號處理電路。（5）.快速響應(yīng) 15秒慢流動的空氣中穩(wěn)定性好,低溫飄,抗化學(xué)腐蝕性強(qiáng)。%（2）.介質(zhì)溫度范圍 25 ~+85℃。（4）.電壓輸出信號（ 電壓，三線） 0 ~ 10V。（6）.電源輸出信號（電流，雙線） 4 ~ 20mA。（2）.電源電壓：AC230V15%/+20%，50/60Hz177。旋轉(zhuǎn)行程機(jī)械可調(diào)。（5）.運(yùn)行溫度：20~+60℃（5~+140℉）。15%，50/60Hz。（3）.額定推力：1800N。根據(jù)冷凍水泵、冷卻水泵的額定電壓選擇220V的低壓變頻器。 （2）.通用磁通矢量控制，1Hz時150%轉(zhuǎn)矩輸出。 （4）.內(nèi)置ModbusRTU協(xié)議。 （6）.帶安全停止功能。本次課程設(shè)計，主要從河源職業(yè)技術(shù)學(xué)院學(xué)術(shù)報告廳中央空調(diào)系統(tǒng)能耗以及長久發(fā)展要求，進(jìn)行節(jié)能改造。因此，大大的節(jié)省了河源職業(yè)技術(shù)學(xué)院學(xué)術(shù)報告廳的能耗；也是報告廳自動化進(jìn)一步提升。在進(jìn)行設(shè)備改造方面，由蔡志敏老師帶領(lǐng)進(jìn)行實地考察與設(shè)備選型。再次萬分感謝蔡志敏指導(dǎo)老師的幫助以及鼓舞。姚衛(wèi)豐《樓宇設(shè)備監(jiān)控及組態(tài)》。張建一、李莉《制冷空調(diào)裝置節(jié)能原理與技術(shù)》。王慧杰 《DDC與DCS集散型控制系統(tǒng) 》期刊論文 2002。您好，為你提供優(yōu)秀的畢業(yè)論文參考資料，請您刪除以下內(nèi)容，O(∩_∩)O謝謝?。。surveyrecentlytothehealthChinese6,sNationalforCare,ChinaDevelopmentandMedicine,leadingChinesepany,theofoneapiledtopcareexpertsChinadistributedmultiplepartners,wellofflineeventsinmiddleandschoolswillreleasedonsurveyandandimportantly,guidelinesparentsyouthhowcaretheandmyopiaagrowinginssociety,alsoattachedtheisonlydiseasemakesseeblurrily,alsotosuchglauapressuretheandcauseblindness,ZhouaneyespecialistBeijingisimportantparentschildrenknowtheandforeyes.ThereaboutmillionpatientsChina.Chinesepatients,30millionsevereaccordingZhouTheofamongschoolcollegeisthanpercent,andsituationcontinuouslyheZhu,withChinaDevelopmentCenter,longofstudy,ofespeciallyactivities,attachmentelectronicaresomethereasonsthemyopiaandincreasepatients,Chinamadeprogressimprovinghardwarefacilitieslightinginsaidhopessurveyalertonthreateningandhelpmedicaltoguidelineandstoforbasedontimelyfactualtheofeventsalsoheldsixincludinginandinprovince,educateontoforafterthestarted. More and more Chinese are jogging to get and stay fit. Most joggers will run alone, but some will jog with friends or even coaches. The Beijing Olympic Forest Park is one of the most popular spots. It is packed with runners in the afternoon, usually after work, and at weekends. Jogging after a whole day39。s smoggy days. If the smog is severe, I39。ll wear a mask, or just ignore the smog and go on jogging, she said. For those who are not so athletic, jogging also has its attractions. Wu Houbin started roughly two years ago, when he was severely obese. Within two months, his weight dropped from 82 kilograms to 64 kilograms. The success helped him recover health, and he has made friends. Jogging does not require speed, but stamina. If you want to stick to the game, you need to take it as a mission, a habit, and then eventually a hobby, Wu said. But persevering with jogging is not always easy. Jogging is beneficial for heartlung function, and the skeletal system, but doctors say improper technique damages the joints, especially the knees and ankles. Excessive jogging wears down the body, and harms one39。s Pink Revolution, an annual campaign that seeks to raise awareness and funds for breast cancer research, the hotel recently announced. A major sponsor of the campaign for three years in a row, Conrad Maca