Measurement of steam used in factories and steam properties
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Our factory uses a thermal power plant to supply steam. The temperature is generally 210 degrees Celsius and the pressure is generally 3.7 kg. This point is the midpoint of the gas supply pipeline and is also our measurement point. The flow meter is a differential pressure gauge with temperature and pressure compensation. The total length of the pipeline is about 150 meters, the diameter is about 300mm, and the instantaneous flow rate is generally 18 tons. According to the thermal power plant, the gas supplied is superheated steam. Looking at the table, it is confirmed that the temperature and pressure do not correspond to saturated steam. I would like to ask 1. Is it possible that the thermal power plant maliciously adds water and air to the steam to affect the measurement (the gas consumption of our plant accounts for 80% of the gas produced by the thermal power plant, which does not generate electricity but only supplies gas), 2. The nature of the steam at the air inlet of our plant. 3. After air intake, connect 6 sub-pipes through the steam drum, and the sub-pipes are connected to each machine. The machine uses steam directly into the water or through a heat exchanger. The sub-pipes are all 100 meters long and have diameters ranging from 80-125mm. Please tell me about the steam properties of the machine's gas point. 4. There are no drains in the branch pipes and main pipes, but there are drain traps on the heat exchanger. Do I need to install it?
1. I have never heard of anyone adding air and water to superheated steam in order to make money. Even adding it will reduce the steam quality. 2. The steam in your factory is superheated steam. 3. Still superheated steam. It is estimated that your factory has high temperature requirements and low pressure requirements. 4. It is best to install a hydrophobic device, otherwise where will the condensed water be discharged when starting and stopping?
1. It is impossible for a thermal power plant to maliciously add air to the steam! As for adding water, it may be the need to adjust the temperature, not malicious, and for superheated steam, most of the added water has been vaporized, that is, the added water has also turned into steam. 2. According to your statement, the steam pressure is 3.7bar and the temperature is 210 degrees. Looking at the steam properties table, we know that the saturation temperature of 3.7bar steam is 140 degrees, so the thermal power plant supplies you with superheated steam. 3. The nature of the steam entering each machine depends on the nature of the steam entering each machine, mainly temperature and pressure. This determines the nature of the steam, but I guess it should all be superheated steam. 4. Both the main pipe and branch pipes need to be equipped with drain devices. Because you are using superheated steam, the problem is not likely to be big during normal operation because condensation water is rarely generated. However, I wonder how you warm the pipes when you are driving after parking (for example, for a day or a few days)? Because a large amount of condensation water will be generated when the pipes are warmed. Without drainage, it is very dangerous and prone to water hammer, posing a threat to equipment or personal safety!
Thank you for your replies, they are very helpful to me. The pipes in our factory are confirmed to be dn250, and the boiler in the thermal power plant is a 35-ton chain furnace. In order to increase the measurement value, can the thermal power plant adopt various methods such as adding compressed air to the pipeline? The temperature and pressure of the superheated steam coming out of his boiler is much higher than the temperature and pressure entering our factory. Water is usually used to reduce the temperature and pressure, so there is no need to consider the temperature and pressure drop caused by adding air. The two factories use orifice flowmeters for measurement, and the settlement is quality.