本文選題：循環(huán)冷卻水系統(tǒng) + 優(yōu)化��； 參考：《青島科技大學》2017年碩士論文

【摘要】：循環(huán)冷卻水系統(tǒng)在工業(yè)應用中具有較大的節(jié)水、節(jié)能潛力。而目前循環(huán)冷卻水的研究方向主要集中在系統(tǒng)的節(jié)水或節(jié)能、冷卻塔模型方面。本文結合以往研究成果,提出設置多級中間水道對循環(huán)冷卻水系統(tǒng)進行優(yōu)化,并以此為前提建立考慮水冷器、冷卻塔等裝置的循環(huán)冷卻水系統(tǒng)的優(yōu)化模型,從而確定循環(huán)冷卻水系統(tǒng)的優(yōu)化設計方案,主要研究內容如下:首先,通過對當前循環(huán)冷卻水系統(tǒng)水冷器網(wǎng)絡優(yōu)化方法的對比和分析,本文在水夾點分析的基礎上提出多級中間水道的循環(huán)冷卻水優(yōu)化方法,該方法能夠明顯提高冷卻水的返塔水溫,從而減少系統(tǒng)的循環(huán)冷卻水量。文中同時總結出水冷器網(wǎng)絡置入多級中間水道的設計步驟,并利用實例驗證了通過設置中間水道的方法可將循環(huán)水量減少60%,證明了該方法的有效性。其次,本文分析了冷卻塔性能的評價指標。并利用冷卻塔模型對冷卻塔的性能進行評價,實例計算表明,當循環(huán)冷卻水系統(tǒng)水冷器網(wǎng)絡中置入多級中間水道后,由于進塔水溫升高和循環(huán)水量減少,引起冷卻塔進出口溫差加大、冷卻極限接近度減小、冷卻塔的效率系數(shù)得到有效提升,表明了加入中間水道后對冷卻塔性能的提升具有重要作用,可以大大節(jié)省設備投資。另外,本文以操作費用和設備費用之和(即總費用)為目標函數(shù)建立數(shù)學模型,其中,設備費用主要考慮冷卻塔的設備投資和以換熱面積表示的水冷器設備費用,操作費用主要考慮系統(tǒng)運行過程中循環(huán)水泵的耗電費用、補充新鮮水費用及投加藥劑費用。采用非線性規(guī)劃方法進行求解。并在此基礎研究了出塔水溫對目標函數(shù)的影響規(guī)律,確定了最佳出塔水溫,使得系統(tǒng)運行1年的總費用最少。最后,本文以某廠年產(chǎn)15萬噸TDI(甲苯二異氰酸酯)部分裝置為工程實例進行驗證,優(yōu)化其系統(tǒng)結構配置和操作參數(shù)。與之前水冷器并聯(lián)連接相比,(1)優(yōu)化后,水冷器網(wǎng)絡采用具有二級中間水道的結構配置,循環(huán)水量降低81.3%;(2)優(yōu)化后,冷卻塔性能有所提升,其中冷卻水進出塔溫差增大387.3%,冷卻極限接近度降低60%,冷卻塔效率系數(shù)升高61%;(3)優(yōu)化后,系統(tǒng)的最佳出塔水溫為27℃,比優(yōu)化前降低了3℃,此時雖然系統(tǒng)的設備費用升高了30.2%,但操作費用降低了81.3%,總費用降低了73.3%。
[Abstract]:Circulating cooling water system has great water saving and energy saving potential in industrial application. At present, the research direction of circulating cooling water is mainly water saving or energy saving, cooling tower model. Combined with the previous research results, this paper puts forward the optimization of circulating cooling water system by setting up multi-stage intermediate waterways, and establishes the optimization model of circulating cooling water system considering water cooler, cooling tower and so on. The main research contents are as follows: firstly, through the comparison and analysis of the network optimization methods of water cooler in the current circulating cooling water system, Based on the analysis of water pinch point, this paper presents an optimization method for circulating cooling water in multistage intermediate waterways. This method can obviously increase the water temperature of cooling water back to the tower and thus reduce the circulating cooling water quantity of the system. At the same time, the design steps of the water cooler network are summarized in this paper, and the effectiveness of this method is proved by using an example to verify that the circulating water volume can be reduced by 60% by setting the intermediate channel. Secondly, the performance evaluation index of cooling tower is analyzed. The performance of the cooling tower is evaluated by using the cooling tower model. The example calculation shows that when the multi-stage intermediate channel is placed in the water cooler network of the circulating cooling water system, the water temperature of the inlet tower increases and the circulating water quantity decreases. As a result, the inlet and outlet temperature difference of cooling tower is increased, the cooling limit approach is reduced, and the efficiency coefficient of cooling tower is effectively raised, which indicates that adding intermediate channel plays an important role in improving the performance of cooling tower and can greatly save equipment investment. In addition, the mathematical model is established with the sum of operation cost and equipment cost (that is, total cost) as the objective function, in which the equipment cost mainly considers the equipment investment of cooling tower and the equipment cost of water cooler expressed by heat exchange area. The operating cost mainly includes the power consumption cost of circulating water pump, the cost of fresh water and the charge of reagents during the operation of the system. The nonlinear programming method is used to solve the problem. On this basis, the influence of water temperature on the objective function is studied, and the optimum water temperature is determined, so that the total cost of the system running for one year is the least. Finally, a project example of a plant with an annual output of 150000 tons of TDI (toluene diisocyanate) is given to optimize the system configuration and operation parameters. Compared with the previous parallel connection of the water cooler, the cooling tower performance has been improved after the optimization of the water cooler network with the configuration of a two-stage intermediate waterway and the reduction of the circulating water quantity by 81.33 / 2). After the cooling water inlet and outlet tower temperature difference increases 387.3%, the cooling limit approach degree decreases 60%, the cooling tower efficiency coefficient increases 61% and the cooling tower efficiency coefficient is increased, the optimum water temperature of the system is 27 鈩，

本文編號：1788608