外文翻譯---太陽能熱水系統(tǒng)研究背景

1、<p><b>　　附錄</b></p><p>　　SOLAR WATER HEATING BACKGROUND</p><p>　　Using the sun’s energy to heat water is not a new idea. More than one hundred years ago, black painted water tan

2、ks were used as simple solar water heaters in a number of countries. Solar water heating (SWH) technology has greatly improved during the past century. Today there are more than 30 million m2 of solar collectors installe

3、d around the globe. Hundreds of thousands of modern solar water heaters, such as the one shown in Figure 1, are in use in countries such as China, India, Germany, Japan</p><p>　　Figure1: Evacuated Tube Solar

4、 Collector in Tibet, China</p><p>　　In addition to the energy cost savings on water heating, there are several other benefits derived from using the sun’s energy to heat water. Most solar water heaters come

5、with an additional water tank, which feeds the conventional hot water tank. Users benefit from the larger hot water storage capacity and the reduced likelihood of running out of hot water. Some solar water heaters do not

6、 require electricity to operate. For these systems, hot water supply is secure from power outages, as long as</p><p>　　Solar Water Heating Application Markets</p><p>　　Solar water heating market

7、s can be classified based upon the end-use application of the technology. The most common solar water heating application markets are service hot water and swimming pools.</p><p>　　Service hot water</p>

8、;<p>　　There are a number of service hot water applications. The most common application is the use of domestic hot water systems (DHWS), generally sold as “off-the-shelf” or standard kits as depicted in Figure 2.

9、</p><p>　　Figure2: Solar Domestic Hot Water System in Australia</p><p>　　Swimming pools</p><p>　　The water temperature in swimming pools can also be regulated using solar water heat

10、ing systems, extending the swimming pool season and saving on the conventional energy costs. The basic principle of these systems is the same as with solar service hot water systems, with the difference that the pool its

11、elf acts as the thermal storage. For outdoor pools, a properly sized solar water heater can replace a conventional heater; the pool water is directly pumped through the solar collectors by the exi</p><p>　　S

12、wimming pool applications can range in size from small summer only outdoor pools, such as the one shown at a home in Figure 3, to large Olympic size indoor swimming pools that operate 12 months a year.</p><p&g

13、t;　　Figure 3: Unglazed Solar Collector Pool Heating System in Canada</p><p>　　Description of Solar Water Heating Systems</p><p>　　Solar water heating systems use solar collectors and a liquid ha

14、ndling unit to transfer heat to the load, generally via a storage tank. The liquid handling unit includes the pump (used to circulate the working fluid from the collectors to the storage tank) and control and safety equi

15、pment. When properly designed, solar water heaters can work when the outside temperature is well below freezing and they are also protected from overheating on hot, sunny days. Many systems also have a back-up heater<

16、/p><p>　　Collection: Solar radiation is “captured” by a solar collector</p><p>　　Transfer: Circulating liquid transfer this energy to a storage tank; circulation can be natural (thermo siphon syste

17、ms) or forced, using a circulator (low-head pump); and</p><p>　　Storage: Hot water is stored until it is needed at a later time in a mechanical room, or on the roof in the case of a thermo siphon system.<

18、/p><p>　　Figure 4: System Schematic for Typical Solar Domestic Water Heater</p><p>　　Solar collectors</p><p>　　Solar energy (solar radiation) is collected by the solar collector’s abso

19、rber plates. Selective coatings are often applied to the absorber plates to improve the overall collection efficiency. A thermal fluid absorbs the energy collected. </p><p>　　There are several types of solar

20、 collectors to heat liquids. Selection of a solar collector type will depend on the temperature of the application being considered and the intended season of use (or climate). The most common solar collector types are:

21、unglazed liquid flat-plate collectors; glazed liquid flat-plate collectors; and evacuated tube solar collectors.</p><p>　　Unglazed liquid lat-plate collectors</p><p>　　Unglazed liquid flat-plate

22、 collectors, as depicted in Figure 5, are usually made of a black polymer. They do not normally have a selective coating and do not include a frame and insulation at the back; they are usually simply laid on a roof or on

23、 a wooden support. These low-cost collectors are good at capturing the energy from the sun, but thermal losses to the environment increase rapidly with water temperature particularly in windy locations. As a result, ungl

24、azed collectors are commonly used </p><p>　　Figure 5: System Schematic for Unglazed Flat-Plate Solar Collector</p><p>　　Balance of systems</p><p>　　In addition to the solar collecto

25、r, a solar water heating system typically includes the following “balance of system components”</p><p>　　1. Solar collector array support structure, as depicted in the Figure 6;</p><p>　　Figure

26、 6: Solar Array Support Structure</p><p>　　2. Hot water storage tank (not required in swimming pool applications and in some large commercial or industrial applications when there is a continuous service ho

27、t water low).</p><p>　　3. Liquid handling unit, which includes a pump required to transfer the fluid from the solar collector to the hot water storage tank (except in thermo siphon systems where circulation

28、is natural, and outdoor swimming pool applications where the existing filtration system pump is generally used) .it also includes valves, strainers, and a thermal expansion tank.</p><p>　　4. Controller, whic

29、h activates the circulator only when usable heat is available from the solar collectors (not required for thermo siphon systems or if a photovoltaic-Powered circulator is used).</p><p>　　5. Freeze protection

30、, required for use during cold weather operation, typically through the use in the solar loop of a special antifreeze heat transfer fluid with a low-toxicity. The solar collector fluid is separated from the hot water in

31、the storage tank by a heat exchanger; and.</p><p>　　6. Other features, mainly relating to safety, such as overheating protection, seasonal systems freeze protection or prevention against restart of a large s

32、ystem after a stagnation period. Typically, an existing conventional water heating system is used for back-up to the solar water heating system, with the exception that a back-up system is normally not required for most

33、outdoor swimming pool applications.</p><p>　　太陽能熱水系統(tǒng)研究背景</p><p>　　利用太陽能來加熱水的并不是一個新的想法。一百多年前，噴有黑色涂層的水箱被作為最簡單的熱水器在許多國家使用。在過去的一個世紀太陽能熱水(SWH)技術(shù)已經(jīng)大大提高了。今天，全世界已經(jīng)累計安裝有超過3000萬平方米的太陽能集熱器。成千上萬的現(xiàn)代太陽能熱水器,也應(yīng)

34、用于中國、印度、德國、日本、澳大利亞和希臘等國家，如圖1所示,。事實上,在某些國家中法律明確要求太陽能熱水器安裝在任何新住宅建設(shè)項目(例如以色列)。</p><p>　　圖1 中國西藏的真空太陽能集熱管</p><p>　　除了節(jié)約能源, 利用太陽能源來加熱水還有其他的優(yōu)點。大部分的太陽能熱水器帶有一個額外的水箱,這是傳統(tǒng)的熱水箱，它能給用戶帶來更大的熱水存儲容量和降低熱水流失的可能性。一

35、些太陽能熱水器不需要用電，這些熱水系統(tǒng)可以不會因為停電而停止供應(yīng)熱水,只要有足夠的陽光就能工作。太陽能熱水系統(tǒng)也可以用于直接加熱游泳池的水,一個好處就是可以延長室外游泳池的使用季節(jié)。</p><p>　?、盘柲軣崴鞯膽?yīng)用市場</p><p>　　太陽能熱水市場可基于該技術(shù)的最終用途來分類。最常見的太陽能熱水系統(tǒng)的應(yīng)用場合是提供熱水和游泳池。</p><p>&l

36、t;b>　　提供熱水</b></p><p>　　太陽能熱水系統(tǒng)的應(yīng)用形式很多，最常見的是用于戶用型熱水系統(tǒng)(DHWS),通常是賣“現(xiàn)成的”或標準的結(jié)構(gòu)，如圖2所示。</p><p>　　圖2 澳大利亞國內(nèi)的熱水系統(tǒng)</p><p><b>　　游泳池</b></p><p>　　太陽能熱水系統(tǒng)也可以調(diào)

37、節(jié)游泳池中水的溫度、延長游泳池季節(jié)和節(jié)省常規(guī)能源成本。這些系統(tǒng)的基本原理與太陽能提供熱水的原理是一樣的,不同之處在于游泳池本身充當(dāng)儲熱水箱。對于室外泳池,一個適當(dāng)大小的太陽能熱水器可以取代傳統(tǒng)的加熱器,泳池里的水由現(xiàn)有的過濾系統(tǒng)直接泵入太陽能集熱器。</p><p>　　這種游泳池的應(yīng)用范圍可以從只在夏天開放的室外泳池，如圖3所示的家庭用的泳池,到大型的一年12個月都能使用的奧運規(guī)模的室內(nèi)游泳池。</p&g

38、t;<p>　　圖3 加拿大的太陽能集熱器游泳池加熱系統(tǒng)</p><p>　　⑵太陽能熱水系統(tǒng)概述</p><p>　　太陽能熱水系統(tǒng)使用太陽能集熱器和液體處理單元轉(zhuǎn)移熱負荷,一般通過儲熱水箱。液體處理單元包括泵(用來使熱水在集熱器和儲熱水箱之間循環(huán))、控制和安全設(shè)備。設(shè)計合理時,太陽能熱水器可以在外界溫度為零度以下時工作,也能防止熱天熱水器內(nèi)部過熱。許多系統(tǒng)也有一個后備加熱

39、器，以確保即使沒有充足的陽光的情況下滿足所有消費者需求。太陽能熱水器執(zhí)行三個基本操作,如圖4所示：</p><p>　　集熱:太陽輻射被太陽能集熱器收集</p><p>　　傳輸:循環(huán)水將熱量到儲熱水箱,循環(huán)可以是自然（熱虹吸系統(tǒng)）或強制的，用循環(huán)裝置（低揚程泵）</p><p>　　儲熱:熱水儲存在機械室，或者在屋頂?shù)臒岷缥到y(tǒng)中，知道后面需要時使用。</p

40、><p>　　圖4典型的太陽能家用熱水器系統(tǒng)示意圖</p><p><b>　　太陽能集熱器</b></p><p>　　太陽能(太陽輻射)由太陽能集熱器的吸收板收集，選擇性涂層常常被運用到吸收板上來效率改善整體的收集效率。一個熱液吸收被收集的能量。</p><p>　　有幾種類型的太陽能集熱器可用來加熱水。太陽能集熱器的選

41、型取決于應(yīng)用環(huán)境的溫度和預(yù)期的季節(jié)(或氣候)溫度。最常見的太陽能集熱器類型有:無釉液體平板集熱器、釉面液體平板集熱器和真空管太陽能集熱器。</p><p><b>　　無釉液體平板集熱器</b></p><p>　　無釉液體平板集熱器,如圖5所示,通常由一個黑色的聚合物制成。它們通常不會有選擇性的涂層和一個絕緣框架在后面;通常是簡單地鋪設(shè)在屋頂上或在一個木制的支持上。

42、這些低成本的集熱器善于捕捉來自太陽的能量,但熱損失隨著水溫的增加而迅速增加，尤其是在多風(fēng)的地方。因此, 無釉集熱器通常用于要求在低溫下輸送能源的場合(游泳池加熱、補給水魚養(yǎng)殖場、加熱過程應(yīng)用等)。在氣候較冷的地區(qū),因高熱損失集熱器只用在夏天工作。</p><p>　　圖5 無釉平板太陽能集熱器系統(tǒng)示意圖</p><p><b>　　系統(tǒng)的平衡</b></p>

43、;<p>　　除了太陽能集熱器,太陽能熱水系統(tǒng)通常包括以下“平衡系統(tǒng)”組件:</p><p>　　1、太陽能集熱器陣列支撐結(jié)構(gòu),如圖6所示。</p><p>　　圖6 太陽能陣列支撐結(jié)構(gòu)</p><p>　　2、貯熱水箱(在持續(xù)提供低溫?zé)崴挠斡境睾鸵恍┐笮蜕虡I(yè)或工業(yè)應(yīng)用場合，這個是不需要的）。</p><p>　　3、液體處理

44、單元,其中包括一個用來在集熱器和貯熱水箱之間傳輸液體的泵(除了在熱虹吸系統(tǒng)中循環(huán)是自然的,在現(xiàn)有的過濾系統(tǒng)中泵一般用于室外游泳池)，它還包括閥門、過濾器、和熱膨脹水箱;</p><p>　　4、控制器,只有當(dāng)可用熱量是從太陽能集熱器得到時用于激活循環(huán)(熱虹吸系統(tǒng)或光伏動力循環(huán)時不需要);</p><p>　　5、冷凍的保護,在寒冷天氣下的操作,通常是通過在一個特殊的加有無毒液體防凍劑來傳熱