發(fā)布時(shí)間：2018-07-04 10:20

  本文選題：可再生能源 + 恒溫厭氧發(fā)酵��； 參考：《蘭州理工大學(xué)》2017年碩士論文

【摘要】：甘肅省蘭州市花莊鎮(zhèn)甘肅荷斯坦奶牛繁育中心—中荷沼氣工程熱電聯(lián)供系統(tǒng)應(yīng)用沼氣內(nèi)燃機(jī)發(fā)電的同時(shí)對發(fā)酵塔、儲(chǔ)氣罐和進(jìn)料進(jìn)行增溫保溫。但內(nèi)燃機(jī)運(yùn)行中所產(chǎn)生的余熱不能滿足對原料預(yù)熱以及維持發(fā)酵塔中溫恒溫發(fā)酵。為保證該沼氣工程的產(chǎn)氣穩(wěn)定,解決因環(huán)境溫度低而造成發(fā)酵塔內(nèi)溫度跨度較大的問題。文中通過構(gòu)建一套太陽能與發(fā)電余熱的增溫保溫系統(tǒng),保證發(fā)酵塔在不同季節(jié)均能維持恒溫厭氧發(fā)酵。闡述了系統(tǒng)的原理,并對系統(tǒng)各部分的熱量進(jìn)行理論計(jì)算。改進(jìn)后的系統(tǒng)應(yīng)用有機(jī)朗肯循環(huán)對煙氣余熱進(jìn)行回收,使系統(tǒng)的總效率提高,主要的研究內(nèi)容與結(jié)果如下:(1)對原有的沼氣工程進(jìn)行全面分析,得出沼氣工程的主要散熱部分為發(fā)酵塔和儲(chǔ)氣罐,需熱部分為進(jìn)料。其中散熱損失占總需熱量的5.9%-15.8%,進(jìn)料需熱量占總需熱量的84.2%-94.1%。該沼氣工程現(xiàn)階段僅依靠內(nèi)燃機(jī)發(fā)電余熱回收系統(tǒng)在寒冷季節(jié)無法提供系統(tǒng)所需熱量,內(nèi)燃機(jī)余熱僅可保證發(fā)酵塔在夏天維持37℃左右發(fā)酵。其它季節(jié),余熱回收系統(tǒng)熱量無法滿足系統(tǒng)在適宜的溫度下發(fā)酵。(2)對該工程進(jìn)行改造,新系統(tǒng)中增加太陽能對原料進(jìn)行增溫,其余熱量用于發(fā)酵塔和儲(chǔ)氣罐進(jìn)行保溫。結(jié)果表明,該沼氣工程需熱量7531.9 MJ·d-1,太陽能與發(fā)電余熱系統(tǒng)供熱量7623.4 MJ·d-1,可使發(fā)酵塔夏季和其他季節(jié)分別維持在52℃和37℃恒溫發(fā)酵,完全滿足該工程的熱量需求。所需太陽能集熱面積為256m2,鮮牛糞總固體質(zhì)量分?jǐn)?shù)為27.5%,進(jìn)料量為40 m3·d-1,將鮮牛糞稀釋到總固體質(zhì)量分?jǐn)?shù)為8%時(shí),所需水量為28.4 m3。蘭州1月份自來水平均溫度0.5℃,太陽能集熱器出口的水溫為50℃,此時(shí)所需太陽能循環(huán)水3.6 m3,自來水為24.8 m3。(3)基于“溫度、品位對口,能量梯級(jí)利用”的原則,文中利用有機(jī)朗肯循環(huán)對低溫?zé)煔庥酂徇M(jìn)行回收利用。利用Aspen plus軟件對余熱回收部分進(jìn)行模擬研究,分析基本的有機(jī)朗肯循環(huán),得出其發(fā)電效率和?效率分別為8.17%和54.16%;進(jìn)行乏氣回?zé)岣倪M(jìn)后,得發(fā)電效率和?效率分別為9.42%和62.61%�；�?zé)嵯到y(tǒng)相比基本的有機(jī)朗肯循環(huán)發(fā)電效率和?效率分別增長1.25%和8.45%。(4)利用太陽能與發(fā)電余熱系統(tǒng)不僅能夠?yàn)檎託夤こ烫峁┏渥愕臒崃?同時(shí)對煙氣運(yùn)用有機(jī)朗肯循環(huán),使系統(tǒng)的能源利用效率顯著提高。本文創(chuàng)新點(diǎn):(1)提出利用太陽能和生物質(zhì)能驅(qū)動(dòng)的、以內(nèi)燃機(jī)為核心的熱電聯(lián)供系統(tǒng),以此來解決西北大中型沼氣工程寒冷季節(jié)“病態(tài)”運(yùn)行狀態(tài)。(2)基于“溫度、品位對口,能量梯級(jí)利用”的原則,文章應(yīng)用有機(jī)朗肯循環(huán)對內(nèi)燃機(jī)中低溫?zé)煔獾挠酂徇M(jìn)行回收利用,使得整個(gè)系統(tǒng)的能源利用效率顯著提高。
[Abstract]:The heat and electricity co-supply system of Gansu Holstein Cow breeding Center, Huazhuang Town, Lanzhou City, Gansu Province, is used to generate electricity from biogas internal combustion engine while the fermenting tower, gas storage tank and feed material are heated and insulated by using biogas internal-combustion engine. However, the residual heat generated in the operation of internal combustion engine can not meet the preheating of raw materials and the maintenance of fermentation tower temperature constant temperature fermentation. In order to ensure the gas production stability of the biogas project, the problem of large temperature span in the fermentation tower caused by low ambient temperature was solved. In this paper, a set of heating and heat preservation system based on solar energy and waste heat of power generation is constructed to ensure that the fermentation tower can maintain constant temperature anaerobic fermentation in different seasons. The principle of the system is expounded, and the heat of each part of the system is calculated theoretically. The improved system uses organic Rankine cycle to recover the waste heat from flue gas, so as to improve the overall efficiency of the system. The main research contents and results are as follows: (1) the original biogas project is comprehensively analyzed. The main heat dissipation part of biogas engineering is fermentation tower and gas storage tank, and the heat requirement part is feed material. The loss of heat dissipation accounts for 5.9- 15.8of the total required heat, and the heat required for feed accounts for 84.2- 94.1 of the total heat required. At this stage, the biogas project can not provide the heat needed by the system only in the cold season depending on the waste heat recovery system of internal combustion engine. The residual heat of the engine can only ensure that the fermentation tower can be fermented at about 37 鈩，

本文編號(hào)：2095751