本文選題：制冷機(jī)組 + 變頻調(diào)速��； 參考：《大連理工大學(xué)》2014年碩士論文

【摘要】：制冷機(jī)組是制冷系統(tǒng)的心臟,降低制冷機(jī)組能耗,提高制冷機(jī)組的自動(dòng)化控制水平是制冷行業(yè)產(chǎn)品技術(shù)發(fā)展的方向和主題。 目前,變頻調(diào)速技術(shù)、計(jì)算機(jī)控制技術(shù)、電力電子技術(shù)等相關(guān)自動(dòng)化技術(shù)在制冷行業(yè)中得到了大力的推廣與應(yīng)用,使得制冷系統(tǒng)在如下兩個(gè)方面的到了質(zhì)的飛躍： (1)提高制冷系統(tǒng)的能效水平,按照受控環(huán)境的溫度波動(dòng)情況制冷量可以按需供給,實(shí)現(xiàn)節(jié)能降耗。 (2)提高制冷系統(tǒng)的智能控制水平,使制冷系統(tǒng)逐步向計(jì)算機(jī)化,數(shù)字化以及可視化方向發(fā)展。 本文將變頻調(diào)速技術(shù)引入到制冷機(jī)組中,運(yùn)用變頻調(diào)速技術(shù)調(diào)節(jié)制冷系統(tǒng)的制冷量,滿足精確的溫度控制要求,提高制冷系統(tǒng)的能效水平。同時(shí)運(yùn)用PLC工業(yè)控制器對(duì)制冷系統(tǒng)進(jìn)行整體的控制與監(jiān)控。 本文通過(guò)對(duì)制冷機(jī)組控制現(xiàn)狀的分析,指出制冷機(jī)組實(shí)現(xiàn)變頻運(yùn)轉(zhuǎn)和自動(dòng)控制的必要性。通過(guò)制冷理論、借助壓焓圖對(duì)制冷系統(tǒng)的各個(gè)部分的運(yùn)轉(zhuǎn)參數(shù)進(jìn)行分析,得出制冷機(jī)組實(shí)現(xiàn)節(jié)能運(yùn)行必須對(duì)制冷劑流量進(jìn)行控制的結(jié)論。 在機(jī)組控制方面,根據(jù)制冷劑的熱力學(xué)性質(zhì)特性,確定壓縮機(jī)吸氣壓力為制冷機(jī)組的控制對(duì)象,通過(guò)壓力傳感器將吸氣壓力信號(hào)傳遞給PLC工業(yè)控制器,由PLC控制器進(jìn)行模數(shù)轉(zhuǎn)換、控制參數(shù)的比較之后輸出4-20mA信號(hào)給變頻器,由變頻器來(lái)控制壓縮機(jī)的轉(zhuǎn)速以達(dá)到控制制冷劑流量的目的。通過(guò)T形圖編程,PLC控制器不僅采集吸氣壓力信號(hào),同時(shí)可以采集排氣壓力、吸氣溫度以及排氣溫度信號(hào),同時(shí)通過(guò)對(duì)其他機(jī)組的保護(hù)信號(hào)的采集,可以對(duì)機(jī)組的運(yùn)行狀況進(jìn)行實(shí)時(shí)監(jiān)控,并在機(jī)組異常狀況下發(fā)出警報(bào)信號(hào)同時(shí)記錄機(jī)組的運(yùn)行狀況。為使制冷機(jī)組有更好的操控性,采取了觸摸屏作為上位機(jī),可以通過(guò)觸摸屏設(shè)置機(jī)組運(yùn)行參數(shù),顯示報(bào)警畫面,記錄機(jī)組運(yùn)行曲線。 完成了半封閉壓縮機(jī)組控制系統(tǒng)的設(shè)計(jì)、安裝、運(yùn)轉(zhuǎn)試驗(yàn),結(jié)果表明變頻調(diào)速技術(shù)能夠通過(guò)調(diào)節(jié)壓縮機(jī)的轉(zhuǎn)速,在不同運(yùn)轉(zhuǎn)負(fù)荷情況下為制冷系統(tǒng)提供所需要的制冷量,使制冷機(jī)組在部分負(fù)荷下的能效比得到質(zhì)的提高。 整個(gè)控制系統(tǒng)的設(shè)計(jì)提高了制冷系統(tǒng)的控制水平,優(yōu)化了系統(tǒng)的控制方法,提高了系統(tǒng)的控制精度,擴(kuò)大了制冷機(jī)組在各個(gè)領(lǐng)域的應(yīng)用范圍,滿足了日益多樣的工藝要求。
[Abstract]:Refrigeration unit is the heart of refrigeration system. Reducing energy consumption of refrigeration unit and improving automation control level of refrigeration unit are the development direction and theme of refrigeration industry. At present, frequency conversion technology, computer control technology, power electronics technology and other related automation technology in the refrigeration industry has been vigorously promoted and applied, making the refrigeration system in the following two aspects of the qualitative leap: 1) improving the energy efficiency level of the refrigeration system, according to the temperature fluctuation of the controlled environment, the refrigerating capacity can be supplied according to the demand, and the energy saving and consumption reduction can be realized. 2) improving the level of intelligent control of refrigeration system, making the refrigeration system develop towards computerization, digitization and visualization. In this paper, the variable frequency speed regulation technology is introduced into the refrigeration unit, and the refrigeration capacity of the refrigeration system is adjusted by the frequency conversion speed regulation technology, which meets the precise temperature control requirements and improves the energy efficiency level of the refrigeration system. At the same time, the PLC industrial controller is used to control and monitor the refrigeration system as a whole. In this paper, the necessity of frequency conversion and automatic control of refrigeration unit is pointed out by analyzing the control status of refrigeration unit. Based on the refrigeration theory and the analysis of the operating parameters of each part of the refrigeration system with the help of the enthalpy diagram, it is concluded that the refrigerant flow must be controlled to realize the energy-saving operation of the refrigeration unit. In the aspect of unit control, according to the thermodynamic properties of refrigerant, the suction pressure of compressor is determined as the control object of refrigeration unit, and the suction pressure signal is transmitted to PLC industrial controller through pressure sensor. After the comparison of the control parameters, the PLC controller outputs the 4-20mA signal to the converter, and the frequency converter controls the speed of the compressor to achieve the purpose of controlling the refrigerant flow. The PLC controller can not only collect the inspiratory pressure signal, but also collect the exhaust pressure, suction temperature and exhaust temperature signal, at the same time, it can collect the protection signal of other units. The operation condition of the unit can be monitored in real time, and the alarm signal can be sent out under the abnormal condition of the unit to record the operation condition of the unit at the same time. In order to make the refrigeration unit have better control, the touch screen is adopted as the upper computer. The operating parameters of the unit can be set up by the touch screen, the alarm screen can be displayed and the running curve of the unit can be recorded. The design, installation and operation test of the semi-closed compressor unit control system have been completed. The results show that the frequency conversion speed regulation technology can provide the required refrigerating capacity for the refrigeration system under different operating loads by regulating the speed of the compressor. The energy efficiency ratio of refrigeration unit under partial load can be improved qualitatively. The design of the whole control system improves the control level of the refrigeration system, optimizes the control method of the system, improves the control precision of the system, expands the range of application of the refrigeration unit in various fields, and meets the increasingly diverse technological requirements.
【學(xué)位授予單位】：大連理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TB657

【參考文獻(xiàn)】

相關(guān)期刊論文 前5條

1 周乾綱;論變頻空調(diào)的技術(shù)優(yōu)勢(shì)與節(jié)能機(jī)理[J];電機(jī)電器技術(shù);2000年02期

2 劉玲;;交流變頻調(diào)速技術(shù)的優(yōu)勢(shì)與應(yīng)用[J];電氣開關(guān);2010年01期

3 孔曉鳴;許敬德;馬金平;楊冬冬;;基于PLC和觸摸屏的制冷空調(diào)產(chǎn)品檢測(cè)裝置控制系統(tǒng)[J];機(jī)械與電子;2009年01期

4 賀喜林;;PLC的應(yīng)用及發(fā)展[J];科技致富向?qū)?2011年09期

5 曹嚴(yán)亮;張波;李守軍;;簡(jiǎn)談變頻器在冷庫(kù)系統(tǒng)中的應(yīng)用[J];甘肅科技縱橫;2012年03期

，

本文編號(hào)：1784854