本文選題：靜態(tài)混合器 + 直接接觸冷凝器　； 參考：《天津大學(xué)》2015年碩士論文

【摘要】：本文利用SV型和SK型靜態(tài)混合器,并以純金屬鈦粉末燒結(jié)的微泡發(fā)生器作為氣體分布器,開(kāi)發(fā)出一種新型直接接觸冷凝器。本文首先在空氣-水體系中對(duì)兩種新型直接接觸冷凝器的流體力學(xué)性能進(jìn)行測(cè)試,測(cè)量并觀察氣液兩相流體在新型直接接觸冷凝器中的流動(dòng)狀態(tài)、氣泡形態(tài)、氣含率以及壓降情況。實(shí)驗(yàn)結(jié)果表明,在裝有SV型靜態(tài)混合器的冷凝器中,氣泡尺寸較小,氣含率較大且隨氣相流量的增大呈先增大后保持不變的趨勢(shì);氣含率隨液相流量的增大基本保持不變。在兩種直接接觸冷凝器中,壓降均隨氣相及液相流量的增大而增大。裝有SV型靜態(tài)混合器的冷凝器中,壓差較大于SK型。這是由于,SV型直接接觸冷凝器對(duì)于分散相氣泡具有較強(qiáng)的破碎作用,使氣泡尺寸更小,分布更均勻。且SV型靜態(tài)混合器具有較大的比表面積,氣泡上升孔道小,路徑長(zhǎng)。氣泡在上升過(guò)程中受到阻力大,停留時(shí)間長(zhǎng)。在空氣-水實(shí)驗(yàn)基礎(chǔ)上,本研究在水蒸氣-水體系中,進(jìn)一步測(cè)試并比較兩種新型直接接觸冷凝器的流體力學(xué)性能及冷凝傳熱性能。測(cè)試氣體分布器對(duì)于冷凝傳熱性能的影響,包括換熱效率、溫度的軸向分布情況、連續(xù)相與分散相的平均傳熱溫差、體積傳熱系數(shù)以及臨界液相溫度。實(shí)驗(yàn)結(jié)果表明,在新型直接接觸式凝結(jié)器中,由于使用了鈦金屬燒結(jié)成的多孔介質(zhì)作為氣體分布器,使水蒸氣穩(wěn)定均一地進(jìn)入水相中,有效地避免了蒸汽凝結(jié)時(shí)產(chǎn)生的振動(dòng)與噪音。水蒸氣的冷凝過(guò)程主要集中在冷凝器的氣相進(jìn)口位置,冷凝段高度與流體流量有關(guān)。新型直接接觸冷凝器在空氣-水體系下具有較大的平均體積傳熱系數(shù)(35-40 kW·m-3·℃-1),裝有SV型靜態(tài)混合器的直接接觸冷凝器略高于SK型。SK型靜態(tài)混合器具有較小壓降以及臨界液相溫度,因此SK型冷凝器具有更大操作范圍。本研究從實(shí)際應(yīng)用角度出發(fā),考慮到直接接觸冷凝在天然氣接收站中具有重要應(yīng)用,是天然氣接收站穩(wěn)定、安全運(yùn)行的關(guān)鍵技術(shù)。本研究在之前所做研究的基礎(chǔ)上,對(duì)兩種新型直接接觸冷凝器在低溫流體下的流動(dòng)及傳熱性能進(jìn)行研究�？紤]到安全、環(huán)保等問(wèn)題,本研究選在氮?dú)?液氮體系下,對(duì)兩種新型直接接觸冷凝器的性能進(jìn)行研究。實(shí)驗(yàn)結(jié)果表明,新型直接接觸冷凝器在低溫流體體系下同樣表現(xiàn)出良好的性能。正常工作條件下,其平均體積傳熱系數(shù)在25-40 kW·m-3·℃-1范圍內(nèi),SV型冷凝器傳熱性能優(yōu)于SK型,但具有較小的操作范圍。結(jié)果表明:裝有SV型靜態(tài)混合器的新型直接接觸冷凝器較裝有SK型靜態(tài)混合器的新型冷凝器對(duì)分散相氣體的分布更加均勻,具有更好的吸收效果,鈦曝氣器的利用可有效提高換熱效率,并降低水蒸氣冷凝所引起的振動(dòng)與噪聲。
[Abstract]:In this paper, a new direct contact condenser is developed by using SV and SK static mixers and using pure titanium powder sintered microbubble generator as gas distributor. In this paper, the hydrodynamic properties of two new direct contact condensers are tested in the air-water system, and the flow state and bubble morphology of the gas-liquid two-phase fluid in the new direct contact condenser are measured and observed. Gas holdup and pressure drop. The experimental results show that in the condenser with SV type static mixer, the bubble size is smaller, the gas holdup is larger, and the gas holdup increases first and then remains unchanged with the increase of the gas flow rate, and the gas holdup remains basically unchanged with the increase of the liquid flow rate. In both direct contact condensers, the pressure drop increases with the increase of gas and liquid flow. In the condenser with SV type static mixer, the pressure difference is larger than SK type. This is due to the fact that the SV-type direct contact condenser has a strong fragmentation effect on the dispersed bubble, which makes the bubble size smaller and the distribution more uniform. The SV type static mixer has large specific surface area, small rising pore channel and long path. The bubble is subjected to large resistance and long residence time during the rising process. On the basis of air-water experiments, the hydrodynamic properties and condensing heat transfer properties of two new direct contact condensers were further tested and compared in water vapor water system. The effect of gas distributor on condensing heat transfer performance including heat transfer efficiency axial distribution of temperature average heat transfer temperature difference between continuous phase and dispersed phase volume heat transfer coefficient and critical liquid temperature were measured. The experimental results show that in the new direct contact condenser, because the porous medium sintered by titanium is used as the gas distributor, the water vapor enters the water phase stably and uniformly. The vibration and noise caused by steam condensation are effectively avoided. The condensing process of water vapor is mainly concentrated at the inlet position of the condenser, and the height of the condensing section is related to the flow rate of the condenser. The new direct contact condenser has a large average volumetric heat transfer coefficient of 35-40 kW m-3 鈩，

本文編號(hào)：1862774