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.

沼气提纯设备在操作蒸汽加热器时注意：要经常检查蒸汽加热器的冷凝水的液位情况。水液位高将会影响换热的温度；当发生蒸汽换热器漏气时，将影响加热再生的效果。所以要经常检查换热后的气体中的含湿情况，一般水分含量应小于1×10-6(露点温度-65℃)。污氮出口温度作为操作的依据。加热阶段刚开始，加热气体使靠近空气出口分子筛床层的温度升高，并供给水分、二氧化碳脱附能，故本身温度又迅速下降，污氮出口温度甚至会降低到-10℃，然后才逐渐升高。当污氮出口温度达到100℃时，停止加热。

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.

冷凝蒸发器的总传热系数主要取决于蒸发侧的传热情况，液面高对提高传热系数有利。虽然提高液氧面会使氧的平均饱和温度略有提高，对传热平均温差不利(略有降低)。沼气提纯设备调整好上塔精馏工况，努力提高平均氮纯度。平均氮纯度的高低标志着氧损失率的大小。

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.

而平均氮纯度又取决于污氮纯度的高低，因为污氮气量占的比例大。污氮的纯度主要也是靠下塔提供合乎要求的液氮来保证的。若有漏气，应排放掉气体，待消除后再次进行升压。每上升1MPa，暂停进气，检查一次，直至达到设备允许的最高工作压力。拆除气源进气管接头。用肥皂水检查高压空气进口法兰、膨胀机进口阀、高压吹除阀和压力表等处有否漏气。

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.

沼气提纯设备设备阻力增加。由于塔板、液空吸附器或过冷器堵塞，液空、液氮节流阀开度过小或被堵塞，将造成下塔压力升高，进塔空气量减少。当切换式换热器冻结时，也将造成系统的阻力增加，进塔空气量自动减少。由于环境的问题，空气中的N2O的浓度不断增加。况且电子等行业对氧产品的纯度要求越来越高(99.99%～99.9999%)，因此，对加工空气中的N2O的清除比过去更重要。较好的清除方法是寻找合适的分子筛，在分子筛纯化器中将加工空气中的H2O、CO2、C2H2、N2O共吸附而清除。

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.