直接式原生污水源熱泵系統(tǒng)的防堵技術(shù)及換熱特性研究_圖文

1、博士學位論文直接式原生污水源熱泵系統(tǒng)的防堵技術(shù)及換熱特性研究CLOG-PROOF TECHNIQUE AND HEATEXCHANGE CHARACTERISTIC RESEARCHOF THE DIRECT UNTREATED SEWAGESOURCE HEAT PUMP SYSTEM莊兆意哈爾濱工業(yè)大學2012年7月國內(nèi)圖書分類號：X703.3 學校代碼：10213 國際圖書分類號：628.2 密級：公開工學博士學位論文直接式原生污水源熱泵系統(tǒng)的防堵技術(shù)及換熱特性研究博 士 研究生：莊兆意導 師：孫德興 教授申 請 學 位：工學博士學 科、專 業(yè)：供熱、供燃氣、通風及空調(diào)工程 所 在 單

2、位：市政環(huán)境工程學院答 辯 日 期：2012年7月授予學位單位：哈爾濱工業(yè)大學Classified Index：X703.3Dissertation for the Doctoral Degree in EngineeringCLOG-PROOF TECHNIQUE AND HEATEXCHANGE CHARACTERISTIC RESEARCHOF THE DIRECT UNTREATED SEWAGESOURCE HEAT PUMP SYSTEMCandidate ：Zhuang Zhaoyi Supervisor ： Prof. Sun DexingAcademic Degree App

3、lied for ：Doctor of Engineering Specialty ： Heating, Gas Supplying, Ventilation& Air-conditioning EngineeringAffiliation ： School of Municipal andEnvironmental EngineeringDate of Defence：July,2012 Degree-Conferring-Institution ：Harbin Institute of Technology摘 要摘 要城市污水中蘊含有豐富的低位熱能，將其作為熱泵的冷熱源為建筑供熱空

4、調(diào)具有巨大的開發(fā)利用價值。城市污水的水質(zhì)極為惡劣。其熱工與流動性能與清水有很大不同。污水處理廠中的二級出水（排放水）接近清水的水質(zhì)，但由于污水處理廠多位于遠離城市建筑群的郊區(qū)，因此真正具有巨大開發(fā)利用價值的是遍布城區(qū)污水渠中的原生污水。傳統(tǒng)的熱泵空調(diào)機組對水質(zhì)有嚴格的要求。因此目前在利用原生污水的熱泵系統(tǒng)中多為避免污水直接進熱泵系統(tǒng)的蒸發(fā)器或冷凝器而設(shè)置一個中間換熱的措施，即所謂“間接式系統(tǒng)”，這種間接式系統(tǒng)不僅要增加中間換熱設(shè)備而且要增加系統(tǒng)的火用損失，故開發(fā)污水直接進機組的熱泵系統(tǒng)，即所謂“直接式系統(tǒng)”，從污水源熱泵技術(shù)產(chǎn)生以來就對學術(shù)與工程界具有巨大的誘惑力。直接式污水源熱泵系統(tǒng)由于污水

5、水質(zhì)的特殊性，必須解決以下關(guān)鍵問題：（1）對過濾和防阻塞的效率和可靠性提出了更高的要求；（2）必須認清污水的流動、換熱以及污垢熱阻的特性與規(guī)律；（3）必須認清污水蒸發(fā)器、冷凝器的換熱特性；（4）直接式熱泵系統(tǒng)兩換熱器的合理匹配與性能。本文對此主要進行了下述研究工作：直接式污水源熱泵系統(tǒng)能夠長時間連續(xù)安全換熱，首要前提是必須保證大尺度污物不進入機組的換熱器中。針對已在間接式污水源熱泵系統(tǒng)中普遍應用的污水防阻設(shè)備，通過工程實踐和測試，總結(jié)發(fā)現(xiàn)：（1）絲狀纖維類污物是阻塞濾面的最大誘因；（2）參考傳統(tǒng)做法，僅靠過濾孔直徑難以衡量防阻機濾面的過濾與再生能力；（3）不可避免的存在內(nèi)漏混水的情況。論文建立

6、了以纏繞長度、反沖效率、內(nèi)漏率、換熱保證率為核心的，包括濾孔直徑、反沖面積比、轉(zhuǎn)速、阻力等在內(nèi)的防阻機設(shè)計指標體系，并通過工程測試確定了最佳的纏繞長度、反沖面積比和清潔周期，為防阻的科學合理設(shè)計及工程選用提供了合理依據(jù)。設(shè)計并在哈爾濱太平污水處理廠搭建了城市原生污水性能研究實驗臺，實驗研究了城市原生污水在各種管材圓管內(nèi)紊流流動時的污垢熱阻特性，流動阻力特性及對流換熱特性。通過大量實驗數(shù)據(jù)總結(jié)出各種常用換熱管內(nèi)污垢熱阻增長規(guī)律，以及污垢熱阻穩(wěn)定值與管內(nèi)污水流速的函數(shù)關(guān)系、污水紊流流動的阻力系數(shù)計算式及換熱準則關(guān)聯(lián)式。實驗表明污垢增長模型為時間的漸進型函哈爾濱工業(yè)大學工學博士學位論文數(shù)，在同管徑同

7、流速下污水的流動阻力系數(shù)約為清水的1.081.12倍，對流換熱系數(shù)約為清水的0.750.82倍。這些基礎(chǔ)數(shù)據(jù)與經(jīng)驗公式為污水源熱泵系統(tǒng)的換熱設(shè)備研發(fā)、系統(tǒng)設(shè)計等提供了較為可靠的依據(jù)。依據(jù)污水流動、換熱及污垢熱阻特性、換熱管污水側(cè)難以強化換熱的特點，建立了污水蒸發(fā)器與冷凝器的分布參數(shù)模型，編制了仿真程序并進行了大量的數(shù)值研究，給出了污水蒸發(fā)器和冷凝器的傳熱系數(shù)范圍，以及污水溫度和流量變化對換熱器換熱特性的影響規(guī)律。發(fā)現(xiàn)與常規(guī)水源熱泵的兩換熱器相比，污水蒸發(fā)器與冷凝器內(nèi)污水以四流程為宜，冷凝器內(nèi)蒸汽過熱段所占比例較大，過熱對冷凝換熱影響明顯，為系統(tǒng)換熱器設(shè)計以及系統(tǒng)性能分析打下基礎(chǔ)。通過直接式污水

8、源熱泵系統(tǒng)建模與數(shù)值仿真，給出了直接式系統(tǒng)的效能范圍，以及污水溫度對效能的影響規(guī)律。規(guī)定了污水源熱泵機組的標準設(shè)計工況，并深入分析了污水蒸發(fā)器、冷凝器面積匹配比與機組制熱量、制冷量、出力比之間的關(guān)系。由于污水源熱泵機組具有更大的適宜面積比范圍和出力比范圍，提出不同地區(qū)采取不同面積比進行熱泵機組設(shè)計的理念。最后給出了非標準工況下熱泵機組的特性以及設(shè)計與選型原則。本文通過研究主要解決了直接式污水源熱泵系統(tǒng)所面臨的防堵塞可靠性、污水流動與換熱計算方法、污水蒸發(fā)器與冷凝器的換熱特性、機組換熱器匹配等問題，為直接式污水源熱泵技術(shù)的發(fā)展奠定了一定的理論基礎(chǔ)。關(guān)鍵詞：原生污水；直接式系統(tǒng)；熱泵；防堵塞性能；

9、匹配AbstractAbstractMunicipal sewage contains so abundant low level heat that it will mean a huge value for development and utilization when used as a cold and heat source of heat pumps for heating and air-conditioning system of buildings.The water quality of municipal sewage is extremely poor and the

10、 thermal and flow properties of it are quite different from those of clear water. In contrast, the water quality of secondary effluent from sewage treatment plants (discharge water is close to that of clear water. However, sewage treatment plants are mostly located in suburbs far away from the city

11、buildings, so it is exactly untreated sewage all over the city sewers that will mean the huge value for development and utilization.Traditional heat pump air conditioning units have strict requirements on water quality. Therefore, measures of intermediate heat-transfer are often taken in the present

12、 heat pump system based on untreated wastewater to avoid sewage flowing directly into the evaporator or condenser of the system which is the so-called "indirect system" and not only introduces extra intermediate heat-transfer devices but also increases system energy loss. So the developmen

13、t of heat pump system namely the so-called "direct system" allowing sewage to enter the units directly shows a great allure on the academic and engineering fields from the origin of the technology of sewage-source heat pumps.Considering the specialty of the water quality of sewage, direct

14、sewage-source heat pump system must solve the following key problems. Firstly, higher requirement is needed for efficiency and reliability of filtering and anti-blocking. Secondly, the feature and discipline of flow, heat-transfer and fouling heat resistance of sewage must be recognized. Thirdly, th

15、e heat-transfer performance of sewage evaporator and condenser should be recognized as well. At last, reasonable match and performance of the two machines of direct heat system need to be taken into consideration. This paper mainly introduces the research work on the mentioned techniques as follows.

16、The primary precondition of safe and enduring heat-transfer for direct sewage source heat pump set is to guarantee that large-scale contaminant of all shapes cannot enter the heat exchanger of the set. Corresponding to the universally哈爾濱工業(yè)大學工學博士學位論文employed sewage clog-proof machine in indirect sewa

17、ge source heat pump systems, we have performed engineering practice and test, according to which we make following conclusions. Firstly, filamentous contaminant is the main incentive of blocking filter surface. Secondly, referring to the traditional method, it is tough to measure the filtration and

18、regeneration ability of the clog-proof machines filter surface only with the diameter of filter hole given. Thirdly, the condition of internal leakage mixing water exists inevitably. The paper establishes a design index system of clog-proof machine including filter pore diameter, recoil area ratio,

19、rotating speed, resistance and so on, and winding length, recoil efficiency, internal leakage rate and heat-transfer guaranteed rate are the core of the index system. The paper also defines the optimal filter pore size, recoil square ratio and cleaning period of the clog-proof device by engineering

20、tests, all three of which provide reasonable foundation for scientific and rational design of clog-proof device for engineering application.An experiment table focusing on city untreated sewage properties research has been designed and constructed in Harbin Taiping sewage treatment plant as to be me

21、ntioned in the paper. Experiments have been executed on the fouling heat resistance performance, flow resistance characteristics and flow and heat-transfer characteristics of urban untreated sewage turbulent flow in a variety of pipes. Through considerable experimental statistics, we can reach such

22、conclusions as fouling heat resistance growth disciplines for kinds of common heat-transfer pipes, the function between the stable value of fouling thermal resistance and the sewage flow rate in the pipe, an expression for resistance coefficient of sewage turbulent flow and finally a heat transfer c

23、orrelation formula. The experiment results demonstrate fouling growth model as a progressive function of time. Specifically, experiments verify that with same pipe diameter and flow rate, the flow resistance coefficient of wastewater is approximately 1.081.12 times that of clear water, whereas the c

24、onvective heat transfer coefficient is about 7582 percent of that of clear water. These fundamental statistics and empirical formulas provide more reliable basis for heat-transfer device development and system design of sewage source heat pump systems.Based on the sewage flow, heat transfer and foul

25、ing resistance properties and the characteristic of difficulty in heat transfer enhancement at the sewage side of heat transfer tube, a distributed parameter model of the sewage evaporator andAbstractcondenser is established, and simulation programs have been developed and employed to do amounts of

26、numerical study which obtains the scope of sewage evaporator and condenser heat transfer coefficients and the law of influence exerted by sewage temperature and flow changes on their heat transfer properties. It is also found that compared with the two machines of the conventional heat pump, the sew

27、age evaporator and condenser have following prominent characteristics. Four processes are appropriate for wastewater inside the machines, and steam superheating segment in condenser takes up a great proportion. In addition, the impact of superheating on condensation heat transfer is significant. All

28、 the achievements lay the foundation for system evaporator and condenser design and system performance analysis.Through direct sewage source heat pump system modeling and numerical simulation, the efficiency range of direct system and the law of sewage temperatures influence on performance are given

29、. Then we set the standard designed working condition of sewage source heat pump units and do deep analysis on the relationship between the matching ratio of sewage evaporator and condenser area and heat output, cooling capacity and power output of the units. For the greater range of suitable area r

30、adio and power output radio of sewage source heat pump unit, we put forward the concept that different area ratio will be adopted while designing heat pump units in different regions. Finally the characteristics of heat pump units and principles for design and selection are introduced under non-stan

31、dard working conditions.By researching, this paper has mainly solved problems faced by direct sewage source heat pump system such as the clog-proof reliability, sewage flow and heat transfer calculation method, heat transfer properties of sewage evaporator and condenser and the matching of the two d

32、evices, all of which lay theoretical foundation for the development of direct sewage source heat pump system.Keywords : untreated sewage, direct system, heat pump, clog-proof, matching哈爾濱工業(yè)大學工學博士學位論文符號表A 面積 e t 蒸發(fā)溫度 f C掛壁系數(shù)c t 冷凝溫度 COP 性能系數(shù)T 熱力學溫度 c換熱管單元面積造價 U 熱流密度 p c定壓比熱 u 管內(nèi)流速 d 管段直徑 m u 斷面平均流速 D

33、圓筒直徑 f u網(wǎng)孔濾速 E相對誤差 V 流量EER 能效比 th V 壓縮機理論排氣量 F 面積z 高差 f 沿程阻力系數(shù) 希臘字母G 質(zhì)量流速 負荷比 H水泵揚程 v 比容h對流換熱系數(shù) 機組出力比f h 沿程阻力損失 氣相空隙率 g重力加速度 z 管束修正系數(shù) k 工質(zhì)絕熱指數(shù) f 強化管修正系數(shù) s k 管壁絕對粗糙度 導熱系數(shù) K 總傳熱系數(shù) 動力粘度 L長度 制熱制冷量 M液體的分子量 局部阻力系數(shù) m 質(zhì)量流量 網(wǎng)孔堵塞厚度 N功率 掛壁概率 Nu努謝爾特數(shù) * 時間常數(shù)， NTU 傳熱單元數(shù) 液體的密度 n 流動系數(shù) 稠度系數(shù)P 壓力 濾網(wǎng)的拉應力 Pr Prantl 數(shù) 運動

34、粘度 P 壓差 面積比Q換熱量 工程設(shè)計負荷 ij Q 單元內(nèi)熱負荷 下角標f Q過水流量 f 污垢側(cè) w Q 電加熱功率 c 清潔側(cè) f R污垢熱阻 p 污染狀態(tài) *f R污垢漸近熱阻值h制熱符號表Re Reynolds 數(shù) L 冷流體；損失 r 管半徑 s 夏季；殼程 S 孔板面積比 t 管程 w S 反沖區(qū)的局部阻抗 1 入口 f S 過濾區(qū)的局部阻抗 2 出口 HE S 換熱器及管路的阻抗 in 進口 m t 平均對數(shù)溫差out 出口 ' t 管壁與污水進口處溫差 w 冬季 '' t 管壁與污水出口處溫差 r 制冷劑 , s i t污水進口溫度 d 標況下 ,

35、s o t 污水出口溫度e 蒸發(fā) , w i t 污水進口處管外壁溫度 c 冷凝 , w o t污水出口處管外壁溫度q清水哈爾濱工業(yè)大學工學博士學位論文目 錄摘 要. I Abstract. III 符號表. VI第1章 緒 論.11.1 課題背景及研究意義.11.2 國內(nèi)外研究現(xiàn)狀及分析.61.3 本文的主要研究內(nèi)容.19第2章 直接式污水源熱泵系統(tǒng)的防堵技術(shù)研究.212.1 引言.212.2 污水防阻機的過濾與再生數(shù)學模型.212.3 污水防阻機工程實踐問題總結(jié)與分析.252.4 濾孔纏繞長度及其對反沖效率的影響.292.5 防阻機混水特性及對換熱的影響.312.6 濾面設(shè)計與評價指標.3

36、92.7 防阻機與換熱器的清理維護措施.412.8 本章小結(jié).42第3章 城市原生污水流動與換熱特性實驗.44目 錄3.1 引言.443.2 實驗原理與方法.443.3 實驗平臺設(shè)計與實驗方案.473.4 實驗測試的參數(shù)及方法.503.5 實驗結(jié)果與分析.533.6 實驗系統(tǒng)誤差分析.633.7 本章小結(jié).68第4章 直接式污水源熱泵系統(tǒng)換熱器的換熱特性.704.1 引言.704.2 直接式污水源熱泵系統(tǒng)換熱器整體設(shè)計.704.3 直接式污水源熱泵系統(tǒng)換熱器的仿真模型.814.4 換熱器在非設(shè)計工況下的換熱特性.884.5 本章小結(jié).100第5章 直接式污水源熱泵系統(tǒng)性能與兩換熱器匹配.101

37、5.1 引言.1015.2 直接式污水源熱泵系統(tǒng)的仿真模型.101哈爾濱工業(yè)大學工學博士學位論文5.3 直接式污水源熱泵系統(tǒng)性能的仿真結(jié)果.1095.4 直接式污水源熱泵系統(tǒng)兩換熱器的匹配特性. 1125.5 非標況下兩換熱器匹配與系統(tǒng)性能. 1185.6 本章小結(jié).120 結(jié) 論.122 參考文獻.124 附錄.134 攻讀學位期間發(fā)表的學術(shù)論文及其他成果.138 哈爾濱工業(yè)大學博士學位論文原創(chuàng)性聲明.141 哈爾濱工業(yè)大學博士學位論文使用授權(quán)書.141 致 謝.142 個人簡歷.144ContentsContentsAbstract (In Chinese . Abstract (In E

38、nglish. XINomenclature. XIChapter 1 Introduction. 11.1 Significance and objective.11.2 Literature review and analysis abroad and domestic.61.3 Source and content of this study.19Chapter 2 Clog-proof technique research of direct sewage heat-pump system. 212.1 Introduction. 212.2 Mathematical model of filter and recovery for sewage clog-proof machine.212.3 Summary and analysis engineering practical problem.252.4 Winding length and recoil area ratio.292.5 Effect on heat transfer and characteristics of water mixture.312.6 Design indices of filter area structure.392.7 Meas