Seek expert advice——can negative-pressure, low-temperature steam be converted into high-pressure, high-temperature steam for use in heat exchangers?
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This post was last edited by foam_ZPTK on 2019-6-13 at 15:57. Experts, I’ve recently encountered a rather tricky problem: one of my clients has a system that creates negative pressure, which results in the generation of some steam at a temperature below 100 degrees. The client wants to recover this steam for reuse, but they don’t have any equipment designed for handling steam at low temperatures under negative pressure. I have a question: can negative-pressure, low-temperature steam at below 100 degrees be converted into high-pressure, high-temperature steam at 140 degrees using pressure-boosting equipment for use in heat exchangers? Does negative-pressure steam condense into liquid water during the process of being converted into high-pressure steam? I can’t figure this problem out for the time being; I hope experts can give me some guidance.
Of course, we must abide by the law of conservation of energy. I use a mechanical compressor. Electric power needs to be consumed. Power consumption can be ignored for now; the main concern is whether phase change will occur in the steam as it moves from negative pressure to normal pressure and then to positive pressure. If it turns into water, how much water can be produced? The data can be calculated per ton of steam.
The temperature and pressure of steam are related to each other; it’s not the case with air – one ton of steam corresponds to one ton of water
Think of a pressure cooker: as the pressure increases, the boiling point also rises; at temperatures below the boiling point, it remains water
Thank you; both conservation of mass and conservation of energy must be observed. In my opinion, the process from negative pressure steam to normal pressure and then to positive pressure is one of continuous pressure increase, and without pressure increase, condensation does not occur. (Without considering heat loss), I’m not sure if that’s correct. If the view is correct, it means that negative-pressure steam can be made into high-temperature steam for use in heat exchangers after pressurization
I agree with what you said. By the same logic, when using a container to heat water, if I install a vacuum pump on that container to create a negative pressure inside it, the water will start boiling at a temperature below 100 degrees, and steam will be generated; obviously, the temperature of this steam is also below 100 degrees. Then I will use a pressure-boosting device to increase the pressure of this steam with a temperature below 100 degrees. Since there is a corresponding relationship between steam temperature and pressure, can high-temperature, high-pressure steam at 140 degrees be achieved after passing through the compressor?
Can it be achieved through compression at 100°C to 140°C?
Saturated water vapor results from an increase in temperature and pressure; it is not the case that an increase in pressure automatically leads to an increase in temperature
Under normal circumstances, it can only be used as a heat source for a preheater.
It should be possible; I simulated it using compressor software, and 1 ton of steam requires 130–140 kWh of electricity. It’s just that the cost is a bit high. However, an additional 160 kilograms of steam can be added. Another point is that I think the process of going from negative pressure steam to normal pressure and then to positive pressure is one of continuous pressure increase; therefore, the gas should not condense. Negative-pressure steam should be able to be pressurized to positive pressure for use in steam supply equipment.