蓄冷器運(yùn)行一段時(shí)間后,由于氣流來回沖擊,充填的卵石會(huì)逐漸被夯實(shí)而下沉。此外,卵石磨損或破碎也會(huì)造成卵石量不足。如果卵石充填不嚴(yán)實(shí),氣流就會(huì)帶動(dòng)卵石上下跳動(dòng),容易砸壞內(nèi)部的盤管,造成管子泄漏。沼氣提純?cè)O(shè)備有液空過冷器的空分設(shè)備,在啟動(dòng)前將下塔及主冷的液體排掉一部分,以防止液空過冷器堵塞;在冷端溫度達(dá)-150℃時(shí),應(yīng)盡量降低環(huán)流量,防止二氧化碳堵塞環(huán)流通道;沼氣提純?cè)O(shè)備如果向主冷內(nèi)反充1m3的液氧,相當(dāng)于從外部提供了0.47×106kJ的冷量,約為5000m3的膨脹空氣在2h內(nèi)的制冷量。有的廠曾做過試驗(yàn),啟動(dòng)時(shí)往塔內(nèi)充灌20m3的液氧,對(duì)6500m3/h空分設(shè)備可縮短啟動(dòng)時(shí)間16.5h;對(duì)10000m3/h空分設(shè)備可縮短啟動(dòng)時(shí)間8h以上。
After the cooler operates for a period of time, the filled pebbles will gradually be compacted and sink due to the back and forth impact of the air flow. In addition, the amount of pebbles will also be insufficient due to the abrasion or breakage of pebbles. If the pebbles are not filled tightly, the air flow will drive the pebbles to jump up and down, which is easy to break the internal coil and cause pipe leakage. For the air separation equipment with liquid-air subcooler for biogas purification equipment, part of the liquid in the lower tower and main cooling shall be drained before startup to prevent the liquid-air subcooler from blocking; When the temperature at the cold end reaches - 150 ℃, the circulation flow should be reduced as much as possible to prevent carbon dioxide from blocking the circulation channel; If the biogas purification equipment backfills 1m3 of liquid oxygen into the main cooler, it is equivalent to providing 0.47 from the outside × The cooling capacity of 106kJ is about 5000m3 of expansion air in 2h. Some plants have done tests, filling 20m3 of liquid oxygen into the tower during startup, which can shorten the startup time by 16.5h for 6500m3/h air separation equipment; For 10000m3/h air separation equipment, the start-up time can be shortened by more than 8h.
借助外部冷源也是縮短啟動(dòng)時(shí)間的有效辦法。當(dāng)主冷冷卻結(jié)束,出現(xiàn)液體時(shí),從外部輸入液氧、液空或液氮。輸液的方法是將液體來源與液氧排放閥接通,打開液氧排放閥,把外部液體注入主冷。當(dāng)膨脹機(jī)進(jìn)口的比焓為h1,出口的比焓為h2時(shí),單位數(shù)量的氣體的制冷量即為h1-h2。已知膨脹機(jī)進(jìn)、出口氣體的溫度和壓力,可以從氣體的熱力性質(zhì)圖上查到相應(yīng)的比焓值。分子篩是否充填滿,并且扒平;認(rèn)真封好內(nèi)、外筒人孔,防止相互竄氣;分子篩吸附器在運(yùn)行時(shí),要定期監(jiān)視分子篩溫度曲線和出口二氧化碳的含量,以判斷吸附器的工作是否正常;要密切監(jiān)視吸附器的切換程序、切換壓差是否正常。
Using external cold source is also an effective way to shorten the startup time. When the main cooling is over and liquid appears, input liquid oxygen, liquid air or liquid nitrogen from the outside. The method of infusion is to connect the liquid source with the liquid oxygen discharge valve, open the liquid oxygen discharge valve, and inject the external liquid into the main cooler. When the specific enthalpy at the inlet of the expander is h1 and the specific enthalpy at the outlet is h2, the refrigerating capacity of the unit quantity of gas is h1-h2. Given the temperature and pressure of the gas at the inlet and outlet of the expander, the corresponding specific enthalpy value can be found from the thermal property diagram of the gas. Whether the molecular sieve is filled and leveled; Carefully seal the inner and outer cylinder manholes to prevent mutual gas channeling; When the molecular sieve adsorber is running, it is necessary to regularly monitor the molecular sieve temperature curve and the carbon dioxide content at the outlet to determine whether the adsorber works normally; Closely monitor whether the switching procedure and switching pressure difference of the adsorber are normal.
沼氣提純?cè)O(shè)備閥體內(nèi)的故障主要是閥頂與閥座的密封面不嚴(yán)而造成閥關(guān)不死的現(xiàn)象。常見的是O型橡膠密封圈脫落。這主要與粘結(jié)面不清潔,黏結(jié)劑質(zhì)量不好有關(guān)。
The main failure in the valve body of the biogas purification equipment is that the sealing surface between the valve top and the valve seat is not tight, which causes the valve to fail to close. It is common that the O-ring falls off. This is mainly related to the uncleanness of the bonding surface and the poor quality of the adhesive.
此外,閥座處有異物;閥桿與閥頂兩端的凹凸球面墊圈擰得過死或過松;固定螺帽沒有擰緊,造成閥頂松動(dòng);閥桿發(fā)生彎曲等均可能造成閥關(guān)閉不嚴(yán)等現(xiàn)象。沼氣提純?cè)O(shè)備從實(shí)踐中知道,只要有溫度差存在,就會(huì)自發(fā)地進(jìn)行熱量傳遞。而且,熱量總是從溫度較高的流體傳向溫度較低的流體。溫度差是熱量傳遞的動(dòng)力。對(duì)間壁式、蓄熱式和混合式三種換熱器的傳熱過程并不完全相同,但其基本規(guī)律還是相同的。
In addition, there are foreign matters at the valve seat; The concave and convex spherical washers at both ends of the valve rod and the valve top are screwed too tightly or too loose; The fixing nut is not tightened, causing the valve top to loosen; The bending of the valve rod may cause the valve to be closed loosely. Biogas purification equipment knows from practice that as long as there is a temperature difference, it will spontaneously carry out heat transfer. Moreover, heat is always transferred from the fluid with higher temperature to the fluid with lower temperature. Temperature difference is the power of heat transfer. The heat transfer processes of the three types of heat exchangers are not completely the same, but their basic laws are the same.