【摘要】：當前我國建筑供熱依舊是以燃煤為主,開發(fā)利用低品位可再生清潔能源前景廣闊,是當今能源、建筑和環(huán)境可持續(xù)發(fā)展的必然要求。熱泵系統(tǒng)具有高效節(jié)能和環(huán)保效益顯著的特點,但是各種熱源的問題一直限制了熱泵系統(tǒng)的應用。當前水源熱泵系統(tǒng)主要是提取環(huán)境水源中的顯熱,但是一直忽略了水凝固所釋放出的巨大熱量。本文提出一種基于人工熱源的提取冷水凝固熱熱泵系統(tǒng),并對系統(tǒng)形式、凝固換熱特性、系統(tǒng)運行效率、運行能耗與經(jīng)濟性進行了深入研究。首先,提出了提取冷水凝固熱熱泵系統(tǒng)的系統(tǒng)形式,詳細闡述系統(tǒng)結構、運行原理及系統(tǒng)特點,并對系統(tǒng)中的關鍵問題進行分析。系統(tǒng)的關鍵性問題主要集中在凝固換熱與除冰方面。系統(tǒng)采用液固流化床除冰設備,通過固體顆粒頻繁碰撞去除換熱器壁面冰層;采用大口徑的換熱管束,使得固體顆粒對換熱器壁面有足夠的正向沖擊力。此外對于系統(tǒng)的融冰方法,對比分析了開式冷卻塔與閉式冷卻塔的優(yōu)缺點,分析結果表明,采用開式冷卻塔更能有效融解人工熱源中所儲存的的冰。其次,在理論分析方面,研究了管內(nèi)凝固換熱特性,并在做出適當?shù)暮喕凹僭O后,建立了管內(nèi)凝固特性與換熱特性的物理模型,推導出其數(shù)學表達。定義了凝固當量換熱系數(shù)比Kh來表征凝固換熱比對流換熱的強化程度。通過數(shù)學分析軟件,得到管內(nèi)凝固換熱的規(guī)律,并對之后的實驗研究提供了理論依據(jù)。然后,為了研究系統(tǒng)的實際運行效果,搭建提取冷水凝固熱泵系統(tǒng)的實驗臺。實驗研究表明,液固流化床除冰系統(tǒng)能夠有效去除凝固換熱器管壁上的冰層,但是其運行不穩(wěn)定;凝固換熱條件發(fā)生的最佳工況為防凍液出口溫度在-3~-5℃之間,也就是-4℃左右,此時系統(tǒng)凝固換熱量最大,系統(tǒng)能夠長時間穩(wěn)定運行,此時系統(tǒng)最佳工況下的COP為2.9,熱泵系統(tǒng)仍然具有一定的節(jié)能效果。最后,對提取冷水凝固熱熱泵系統(tǒng)的機組及系統(tǒng)的能耗進行評價分析,分析結果表明,與燃煤鍋爐相比,系統(tǒng)運行能耗降低52.1%。然后通過將系統(tǒng)經(jīng)濟性評價劃分為前期初投資與后期系統(tǒng)運行費用兩部分,以費用年值為依據(jù)進行分析,與其他供熱方式進行對比,分析結果表明,系統(tǒng)具有很好的經(jīng)濟性。
[Abstract]:At present, building heating in our country is still mainly coal burning, and the development and utilization of low-grade renewable clean energy have broad prospects, which is the inevitable requirement for the sustainable development of energy, architecture and environment. Heat pump system has the characteristics of high efficiency, energy saving and environmental protection benefit, but the application of heat pump system is limited by various heat sources. The current water source heat pump system is mainly used to extract sensible heat from environmental water source, but it ignores the huge heat released by water solidification. In this paper, a cold water condensing heat pump system based on artificial heat source is proposed. The system form, solidification heat transfer characteristics, system operation efficiency, operation energy consumption and economy are studied deeply. Firstly, the system form of extracting cold water solidified heat pump system is put forward, the system structure, operation principle and system characteristics are described in detail, and the key problems in the system are analyzed. The key problems of the system mainly focus on solidification heat transfer and deicing. The system adopts liquid-solid fluidized bed deicing equipment to remove the ice layer of heat exchanger wall through frequent collision of solid particles, and adopts large-caliber heat transfer tube bundle to make solid particles have enough positive impact force on the wall of heat exchanger. In addition, the advantages and disadvantages of open cooling tower and closed cooling tower are compared and analyzed. The results show that the open cooling tower can effectively melt the ice stored in artificial heat source. Secondly, in the theoretical analysis, the characteristics of solidification heat transfer in the tube are studied, and after making appropriate simplification and hypothesis, the physical model of the solidification and heat transfer characteristics in the tube is established, and its mathematical expression is deduced. The ratio of equivalent heat transfer coefficient Kh to Kh is defined to characterize the strengthening degree of convection heat transfer in solidification ratio. The law of solidification heat transfer in pipe is obtained by mathematical analysis software, and the theoretical basis for later experimental research is provided. Then, in order to study the actual operation effect of the system, an experimental platform for extracting cold water solidified heat pump system was built. The experimental results show that the liquid-solid fluidized bed deicing system can effectively remove the ice layer on the tube wall of solidified heat exchanger, but its operation is unstable. At about -4 鈩，

本文編號：2137414