气体水含量实验室测定方法研究

Study on the method for Measuring the content of water in gas in laboratory

天然气或炼油生产中各种气体都携带有水分.这些水分对气体的安全生产、使用和输送都造成危害,因此,必须准确测量并严格控制这些气体中的水含量.介绍了实验室测定气体中水含量的常用方法,并分析了各自存在的问题.在此基础上,提出了一种新的实验室测定气体水含量的方法.新方法基于浓硫酸较强的吸水性,气体在通过两个盛有浓硫酸的吸收瓶时浓硫酸将其携带的水分全部吸收,两个吸收瓶质量增加之和即为气体中的水含量.实验结果表明:当浓硫酸所吸收水分的累积量小于10%时,对测定结果不产生影响;在气体流量小于38L/h、温度从室温至70℃的条件下,新方法最大相对误差为0.8%,不同温度下的平均误差小于0.6%.该方法具有简单、方便、准确、快速的特点.

Natural gas and the gases produced in oil refining process contain water. These gases are harmful to safe production and the use and the transportation of them. Therefore, the content of the water must accurately be measured and strictly be controlled. Some methods most in use are introduced by which the content of water in gases is measured in laboratory, and the shortcomings of them are analyzed separately. Based on this, a new method for measuring the content of water in gases in laboratory is put forward. The new method is based on the strong hydroscopicity of concentrated sulfuric acid. The water in gas is completely absorbed when the gas passes in turn through two absorbing bottles filled with concentrated sulfuric acid, and then the sum of the increments of the weights of the two bottles is equal to the weight of the water in the gas. The experimental results show that, the measured result is accurate as long as the mass fraction of the water absorbed by the concentrated sulfuric acid is less than 10% ; the maximum measurement error of this method is 0. 8% when the flow rate of the gas is less than 38 L/h and the temperature of the gas ranges from room temperature to 70 'C ; the average error under different temperatures is less than 0. 6% .The use of the method is simple, convenient, and the measurement result is accurate.