當裝置的冷損增大時,制冷量不足,使得進下塔的空氣含濕量減小,要求在主冷中冷凝的氮氣量增加,主冷的熱負荷增大,相應地液氧蒸發(fā)量也增大,液氧面下降;如果冷凝蒸發(fā)器液氧面過高而下塔液空面過低,可能是由于打入上塔的液空量過大。此時應關小液空節(jié)流閥。反之,若冷凝蒸發(fā)器液氧面過低而下塔液空面過高,則要開大液空節(jié)流閥,以保持冷凝蒸發(fā)器的液面穩(wěn)定。對于臥式分子篩吸附器,由于氣流脈動等原因造成床層起伏不平,出現(xiàn)氣流短路;對于立式分子篩吸附器,由于吸附床層出現(xiàn)空隙,造成氣流短路。
When the cooling loss of the unit increases, the cooling capacity is insufficient, which reduces the moisture content of the air entering the lower tower. The amount of nitrogen condensed in the main cooling is required to increase, and the heat load of the main cooling is increased, accordingly, the evaporation of liquid oxygen is also increased, and the liquid oxygen surface is reduced; If the liquid oxygen level of the condensation evaporator is too high and the liquid air level of the lower tower is too low, it may be due to an excessive amount of liquid air entering the upper tower. At this point, the liquid air throttle valve should be turned down. On the contrary, if the liquid oxygen level of the condensation evaporator is too low and the liquid air level of the lower tower is too high, it is necessary to open the liquid air throttle valve to maintain the stability of the liquid level of the condensation evaporator. For horizontal molecular sieve adsorbers, due to factors such as airflow pulsation, the bed layer fluctuates unevenly, resulting in airflow short circuits; For vertical molecular sieve adsorbers, the air flow is short circuited due to gaps in the adsorption bed layer.
沼氣提純設備在操作蒸汽加熱器時注意:要經常檢查蒸汽加熱器的冷凝水的液位情況。水液位高將會影響換熱的溫度;當發(fā)生蒸汽換熱器漏氣時,將影響加熱再生的效果。所以要經常檢查換熱后的氣體中的含濕情況,一般水分含量應小于1×10-6(露點溫度-65℃)。污氮出口溫度作為操作的依據(jù)。加熱階段剛開始,加熱氣體使靠近空氣出口分子篩床層的溫度升高,并供給水分、二氧化碳脫附能,故本身溫度又迅速下降,污氮出口溫度甚會降低到-10℃,然后才逐漸升高。當污氮出口溫度達到100℃時,停止加熱。
When operating the steam heater for biogas purification equipment, it is important to regularly check the liquid level of the condensate in the steam heater. A high water level will affect the temperature of heat exchange; When a steam heat exchanger leaks, it will affect the effectiveness of heating regeneration. So it is necessary to regularly check the moisture content in the gas after heat exchange, and the moisture content should generally be less than 1 × 10-6 (dew point temperature -65 ℃). The outlet temperature of sewage nitrogen serves as the basis for operation. At the beginning of the heating stage, the heating gas causes the temperature of the molecular sieve bed near the air outlet to increase, and supplies water and carbon dioxide desorption energy. Therefore, the temperature itself rapidly decreases, and the outlet temperature of the nitrogen will even decrease to -10 ℃ before gradually increasing. When the outlet temperature of the sewage nitrogen reaches 100 ℃, stop heating.
冷凝蒸發(fā)器的總傳熱系數(shù)主要取決于蒸發(fā)側的傳熱情況,液面高對提高傳熱系數(shù)有利。雖然提高液氧面會使氧的平均飽和溫度略有提高,對傳熱平均溫差不利(略有降低)。沼氣提純設備調整好上塔精餾工況,努力提高平均氮純度。平均氮純度的高低標志著氧損失率的大小。
The total heat transfer coefficient of the condensation evaporator mainly depends on the heat transfer on the evaporation side, and high liquid level is beneficial to improving the heat transfer coefficient. Although increasing the liquid oxygen surface will slightly increase the average saturation temperature of oxygen, it is unfavorable for the average temperature difference in heat transfer (slightly reduced). Adjust the distillation conditions of the upper tower of the biogas purification equipment and strive to improve the average nitrogen purity. The average nitrogen purity indicates the magnitude of oxygen loss rate.
而平均氮純度又取決于污氮純度的高低,因為污氮氣量占的比例大。污氮的純度主要也是靠下塔提供合乎要求的液氮來保證的。若有漏氣,應排放掉氣體,待后再次進行升壓。每上升1MPa,暫停進氣,檢查一次,直達到設備允許的高工作壓力。拆除氣源進氣管接頭。用肥皂水檢查高壓空氣進口法蘭、膨脹機進口閥、高壓吹除閥和壓力表等處有否漏氣。
The average nitrogen purity also depends on the purity of the polluted nitrogen, as the proportion of polluted nitrogen gas is large. The purity of polluted nitrogen is mainly ensured by providing liquid nitrogen that meets the requirements in the lower tower. If there is a leak, the gas should be discharged and pressurized again after it is eliminated. Stop air intake and check once for every 1MPa increase until the maximum allowable working pressure of the equipment is reached. Remove the air supply intake pipe connector. Use soapy water to check for air leakage at the high-pressure air inlet flange, expander inlet valve, high-pressure blowing valve, and pressure gauge.
沼氣提純設備設備阻力增加。由于塔板、液空吸附器或過冷器堵塞,液空、液氮節(jié)流閥開度過小或被堵塞,將造成下塔壓力升高,進塔空氣量減少。當切換式換熱器凍結時,也將造成系統(tǒng)的阻力增加,進塔空氣量自動減少。由于環(huán)境的問題,空氣中的N2O的濃度不斷增加。況且電子等行業(yè)對氧產品的純度要求越來越高(99.99%~99.9999%),因此,對加工空氣中的N2O的比過去更重要。較好的方法是尋找合適的分子篩,在分子篩純化器中將加工空氣中的H2O、CO2、C2H2、N2O共吸附而。
The resistance of biogas purification equipment has increased. Due to blockage of the tray, liquid air adsorber, or subcooler, the opening of the liquid air and liquid nitrogen throttle valves is too small or blocked, which will cause an increase in the pressure of the lower tower and a decrease in the amount of air entering the tower. When the switching heat exchanger freezes, it will also cause an increase in system resistance and automatically reduce the amount of air entering the tower. Due to environmental issues, the concentration of N2O in the air continues to increase. Moreover, industries such as electronics are increasingly demanding the purity of oxygen products (99.99% to 99.9999%), so the removal of N2O from processed air is more important than in the past. A better cleaning method is to find a suitable molecular sieve and remove H2O, CO2, C2H2, and N2O from the processed air through co adsorption in a molecular sieve purifier.