1.超临界条件下二氧化碳的密度、比热容会急剧增大、压缩性也急剧下降与液

1.超临界条件下二氧化碳的密度、比热容会急剧增大、压缩性也急剧下降与液体相 当，而粘度、导热系数会急剧下降，接近气体的。以上这些变化都是向着有利于管道输 送的方向变化的，所以超临界状态是最有利于大规模、长距离管道输送的状态。 <br>2.实现超临界二氧化碳有三种方式，摩尔流量相同的条件下，从液态转化为超临界 状态所消耗的功耗和能量消耗最小，而气态先转化为液态，再进一步转化为超临界状态 所消耗的能量和系统向外界散发的热量都远小于把气态直接转化为超临界状态的方法。 <br>3.气态管道由于压降较大，一次加压后有效输送距离为37.5km，液态管道由于相态限制，输送距离为204.4km，超临界状态管道若想保持超临界性，则输送距离为128.1km， 若按压降允许计算，则输送距离可以达到1010km，杂质对气态和超临界态管道影响较小，对液态管道的影响较大，当距离超过100km时，影响尤为明显。

1. Under supercritical conditions, the density and specific heat capacity of carbon dioxide will increase sharply, and the compressibility will also drop sharply, which is equivalent to that of liquid, while the viscosity and thermal conductivity will drop sharply, which is close to that of gas. The above changes are all in the direction that is conducive to pipeline transportation, so the supercritical state is the most favorable state for large-scale and long-distance pipeline transportation.<br>2. There are three ways to achieve supercritical carbon dioxide. Under the same molar flow rate, the power consumption and energy consumption required to convert from liquid to supercritical state are the smallest, while the energy consumption and heat dissipated by the system when the gas state is first converted to liquid and then further converted to supercritical state are much smaller than the method of directly converting the gas state to supercritical state.<br>3. Due to the large pressure drop in gaseous pipelines, the effective transportation distance after one pressurization is 37.5km. Due to phase limitations, the transportation distance for liquid pipelines is 204.4km. If supercritical pipelines want to maintain supercritical, the transportation distance is 128.1km. If the pressure drop is allowed to be calculated, the transportation distance can reach 1010km. Impurities have a small impact on gaseous and supercritical pipelines, but a significant impact on liquid pipelines. When the distance exceeds 100km, The impact is particularly significant.

1. Under supercritical conditions, the density and specific heat capacity of carbon dioxide will increase sharply, and the compressibility will also drop sharply, which is similar to that of liquid, while the viscosity and thermal conductivity will drop sharply, which is close to that of gas. All these changes are in the direction of pipeline transportation, so supercritical state is the most favorable state for large-scale and long-distance pipeline transportation.<br> 2. There are three ways to realize supercritical carbon dioxide. Under the same molar flow rate, the power consumption and energy consumption from liquid state to supercritical state are the least, while the energy consumption and heat emitted by the system when the gas state is converted to liquid state first and then to supercritical state are far less than those by the method of directly converting the gas state to supercritical state.<br> 3. Due to the large pressure drop, the effective transportation distance of the gas pipeline after one pressurization is 37.5km, and the transportation distance of the liquid pipeline is 204.4km due to the limitation of phase state. If the supercritical pipeline wants to keep supercritical, the transportation distance is 128.1km, and if the pressure drop is allowed to be calculated, the transportation distance can reach 1010km. Impurities have little influence on the gas pipeline and the supercritical pipeline, but have great influence on the liquid pipeline. When the distance exceeds 100,