The atmospheric temperature is 30 degrees and the relative humidity is 70%. What is the water content in mg/m3? !

Relative humidity of air: refers to the ratio of the vapor pressure of water in the air to the saturated vapor pressure of water at the same temperature and pressure. The ratio of the absolute humidity of humid air to the maximum absolute humidity possible at the same temperature. It can also be expressed as the ratio of the partial pressure of water vapor in humid air to the saturation pressure of water at the same temperature. 1. According to the ASPEN simulation results, the volume content of water in saturated steam with vapor pressure at 30 degrees normal pressure is 3.47/(3.47+90.945)=0.0368. At this time, the saturated vapor pressure of water is 0.0368 * 101.325=3.73kPa, the poster’s 4.4953KPa is a bit high. Then 70% relative temperature corresponds to 0.0368 * 0.7=0.0257, the water content at this time is 0.0257 * 18/(0.0224 * 303/273)=18.6g/m3. Under standard conditions, 1 mol of gas volume corresponds to 22.4L, but at 30 degrees, the influence of temperature must be considered, so 22.4 is a bit low, and the corresponding value at this time should be 22.4 * 303/273=24.86L/mol. 2. The saturation data can also be obtained by looking up the table, which is 30.35g/m3. Calculated at 70%, it is 30.35 * 0.7=21.2g/m3, which is within the same order of magnitude as the calculated result. To sum up, the accurate calculation result is 24.86g/m3.

Relative humidity of air: refers to the ratio of the vapor pressure of water in the air to the saturated vapor pressure of water at the same temperature and pressure. The ratio of the absolute humidity of humid air to the maximum absolute humidity possible at the same temperature. It can also be expressed as the ratio of the partial pressure of water vapor in humid air to the saturation pressure of water at the same temperature. 1. According to the ASPEN simulation results, the volume content of water in saturated steam with vapor pressure at 30 degrees normal pressure is 3.47/(3.47+90.945)=0.0368. At this time, the saturated vapor pressure of water is 0.0368 * 101.325=3.73kPa, the poster’s 4.4953KPa is a bit high. Then 70% relative temperature corresponds to 0.0368 * 0.7=0.0257, the water content at this time is 0.0257 * 18/(0.0224 * 303/273)=18.6g/m3. Under standard conditions, 1 mol of gas volume corresponds to 22.4L, but at 30 degrees, the influence of temperature must be considered, so 22.4 is a bit low, and the corresponding value at this time should be 22.4 * 303/273=24.86L/mol. 2. The saturation data can also be obtained by looking up the table, which is 30.35g/m3. Calculated at 70%, it is 30.35 * 0.7=21.2g/m3, which is within the same order of magnitude as the calculated result. To sum up, the accurate calculation result is 24.86g/m3.

If you have solid basic skills, you can calculate according to what Haiyou said before. . There are actually simpler ones. . . http://www.michell.com/us/calculator/ This is a humidity calculator produced by the famous Michel company, and it is very accurate. .

hehe. My calculation wasn't too wrong, at least it was just a decimal point wrong.

Did you just miscalculate the decimal point? ? ? You took the working condition cube as the standard state cube. . . Haiyou pointed it out to you before. Didn't you see it? Are you still pretending not to know? ? Still don’t know where you went wrong? ? ? Fortunately it was 30 degrees. What if it was 90 degrees? ? Calculate the difference yourself. . If the basic skills are not solid, these basic calculations require help from good software. . . .

Brother, don’t criticize when you come up. I knew in my heart that the difference was not big, so I didn’t count it.

One more wordy sentence. . . . If you look carefully at the screenshot I posted, it will be the result you want. . The saturated vapor pressure of water at 30℃ is 4.24669kPa (what is yours? ), at 70% relative humidity, the partial pressure of water vapor is 4.24669x70%=2.9729kPa. The Michelle software is right, but your basic data is completely wrong. . . . . Look at people's pursuit of data excellence. . .

God, please help me read this post. http://bbs.hcbbs.com/thread-1829521-1-1.html

God, please help me read this post. http://bbs.hcbbs.com/thread-1829521-1-1.html