孟建軍 胡文杰 趙巖 秦義華 陳子默
摘? 要:針對(duì)某越野車系列車型空調(diào)暖風(fēng)系統(tǒng)采暖性能的不足,現(xiàn)重新對(duì)暖風(fēng)系統(tǒng)方案進(jìn)行改進(jìn)優(yōu)化預(yù)研。原車以空氣加熱器作為車廂暖風(fēng)能量的來(lái)源,而優(yōu)化方案采用汽車尾氣回收技術(shù),將發(fā)動(dòng)機(jī)排氣余熱回收利用,通過(guò)發(fā)動(dòng)機(jī)排氣收集換熱裝置和電動(dòng)水泵,對(duì)發(fā)動(dòng)機(jī)冷卻液進(jìn)行二次加熱,提高冷卻液的溫度,解決極寒天氣車廂暖風(fēng)能量不足的問(wèn)題。采用該技術(shù)能減少燃油消耗率,提高續(xù)駛里程,同時(shí)避免空氣加熱器工作時(shí)尾氣泄漏風(fēng)險(xiǎn)和尾氣排放污染;車廂內(nèi)增加車廂暖風(fēng)散熱器和電子風(fēng)扇,解決了原車暖風(fēng)風(fēng)道布置困難,暖風(fēng)風(fēng)速、溫度分布不均,空氣干燥和異味等問(wèn)題。此項(xiàng)技術(shù)的研究及應(yīng)用,解決了越野車輛冬季極寒地區(qū)車內(nèi)采暖問(wèn)題,取得了良好的暖風(fēng)采暖和除霜效果,提高了乘員乘坐舒適性,同時(shí)起到節(jié)能減排的示范效果,具有廣泛地推廣應(yīng)用價(jià)值。
關(guān)鍵詞:越野車;排氣余熱;排氣收集換熱裝置;舒適性;節(jié)能減排
中圖分類號(hào):TK01+8? ? 文獻(xiàn)標(biāo)識(shí)碼:A? ? ?文章編號(hào):1005-2550(2019)03-0002-06
Abstract: In view of the deficiency of heating performance of air conditioning heating system of a series of off-road vehicles, dongfeng automobile company has carried out an improvement and optimization preliminary study on the heating system scheme. The original vehicle use air heaters as the source of the car's warm air energy, and the optimization scheme USES the automobile exhaust recovery technology to recycle the engine's exhaust residual heat, collect the heat exchange device and electric pumps through the engine's exhaust, reheat the engine's cooling fluid, increase the temperature of the cooling fluid, and solve the problem of the car's lack of warm air energy in extremely cold weather. The adoption of this technology can reduce fuel consumption rate, improve driving mileage, and avoid the risk of tail gas leakage and tail gas emission pollution when the air heater works. Add car radiator and electric fan, solve the original car warm air duct layout difficulty, warm air speed, temperature distribution uneven, air drying and odor problems. The research and application of the technology, solve the interior heating problem of off-road vehicle in winter cold area, has obtained the good effect of warm air heating and defrosting, improved occupant comfort, at the same time have the demonstration effect of energy conservation and emissions reduction, has widely application value.
Key Words: Off-road vehicles; Exhaust residual heat; Exhaust collection heat exchanger; Comfort; Energy conservation and emissions reduction
引言
汽車發(fā)動(dòng)機(jī)工作中,燃料燃燒的能量約有30%轉(zhuǎn)變成機(jī)械能使發(fā)動(dòng)機(jī)發(fā)出動(dòng)力;約有30%轉(zhuǎn)變成熱能隨廢氣排出;另外約有30%的熱能傳遞給冷卻液;還有10%的能量以熱輻射形式散發(fā)給周圍大氣,圖1為某柴油發(fā)動(dòng)機(jī)各能量損失功率。因此回收利用發(fā)動(dòng)機(jī)排氣和發(fā)動(dòng)機(jī)冷卻液余熱具有巨大潛能和重要意義。
一般汽車暖風(fēng)的能源來(lái)源于發(fā)動(dòng)機(jī)冷卻液,通過(guò)暖風(fēng)散熱器和風(fēng)機(jī)利用液氣差來(lái)實(shí)現(xiàn)車內(nèi)采暖的要求。多年應(yīng)用經(jīng)驗(yàn)表明,利用發(fā)動(dòng)機(jī)冷卻液余熱的暖風(fēng)采暖方式,能夠較好的適用于車廂容積較小的商用車和乘用車,滿足其采暖需求。而對(duì)于車廂容積較大的越野車、客車,采暖效果一般,溫升慢,體驗(yàn)較差,后排乘員腳部溫度難以達(dá)到標(biāo)準(zhǔn)要求;同時(shí)在冬季使用暖風(fēng)時(shí),發(fā)動(dòng)機(jī)冷卻液溫度低,發(fā)動(dòng)機(jī)長(zhǎng)期在低溫狀態(tài)下運(yùn)行,機(jī)油溫度低潤(rùn)滑不良,發(fā)動(dòng)機(jī)熱效率低,燃油經(jīng)濟(jì)性差,排放差,整車油耗高。
目前車輛采暖性能要求分別按照GJB59.37(-35℃)和GB/T12782(-25℃)標(biāo)準(zhǔn)執(zhí)行。針對(duì)車廂在三排及以上的大容積載人車型,低溫采暖性能要想較好的滿足以上標(biāo)準(zhǔn)的要求,必須要解決如下幾個(gè)方面的問(wèn)題。第一、大車廂容積車型,僅利用發(fā)動(dòng)機(jī)冷卻液余熱作為暖風(fēng)能量顯然是不夠的,需要新的能量作為補(bǔ)充。目前普遍解決辦法如下:一種方式是增加液體加熱器來(lái)提高發(fā)動(dòng)機(jī)冷卻液溫度;另一種方式是,主副駕駛采暖通過(guò)利用發(fā)動(dòng)機(jī)冷卻液余熱的暖風(fēng)來(lái)實(shí)現(xiàn),其余乘員采暖通過(guò)增加空氣加熱器加熱車內(nèi)空氣來(lái)實(shí)現(xiàn)。但這兩種方式均通過(guò)燃燒燃油來(lái)提供采暖所需能量,既不節(jié)能又不環(huán)保,而且成本還高。第二、解決因暖風(fēng)風(fēng)道布置困難而造成的暖風(fēng)風(fēng)速和溫度分布不均的問(wèn)題。目前普遍通過(guò)在車廂內(nèi)增加車廂暖風(fēng)散熱器和電子風(fēng)扇來(lái)解決。用水管代替風(fēng)道作為暖風(fēng)循環(huán)介質(zhì)的輸送通道,尺寸小易布置,壓力損失低,從而解決暖風(fēng)風(fēng)道布置困難的問(wèn)題。通過(guò)電動(dòng)水泵將暖風(fēng)循環(huán)介質(zhì)發(fā)動(dòng)機(jī)冷卻液引到車廂暖風(fēng)散熱器,再通過(guò)電子風(fēng)扇實(shí)現(xiàn)熱交換,實(shí)現(xiàn)暖風(fēng)風(fēng)速和溫度分布的均勻性。