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T C
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- What's the flow rate of steam at 5 barA pressure in a 250 kW power plant?
I want to know what's the flow rate (in kg/s) of saturated steam at 5 barA pressure to the turbines of a 250 kW power plant.
What is the exit pressure from the turbine?T C said:Summary: What's the flow rate of steam at 5 barA pressure in a 250 kW power plant?
I want to know what's the flow rate (in kg/s) of saturated steam at 5 barA pressure to the turbines of a 250 kW power plant.
Wadda you mean? Do you have steam tables or not?T C said:Can't tell that. What's the enthalpy change of the market available power plants using such parameters?
Good. Now since one joule per second is one watt, can you complete the calculation?T C said:73.16 kJ/kg.
Please provide details on how you obtained this result.T C said:73.16 kJ/kg.
This is not correct. It neglects the fact that some of the steam condenses in the turbine. For the adiabatic reversible expansion occurring in the turbine, the entropy per unit mass of the mixture of saturated liquid and saturated vapor leaving the turbine at 1 Bar must equal the entropy per unit mass of the dry saturated vapor entering the turbine at 5 bars. So, on this basis, you need to determine the mass fractions of saturated liquid and saturated vapor exiting the turbine such that this condition is satisfied. Then, using these mass fractions, you need to determine the enthalpy per unit mass of the combined mixture exiting the turbine. For the enthalpy change of the water passing through the turbine, you will then get a value higher than that which you calculated.T C said:By subtracting the gross enthalpy of saturated steam at 1 barA pressure from 5 barA pressure.
Yes, non-condensing non-reheat turbine is clear. Nevertheless, the moisture content of the saturated mixture changes a lot in the turbine. It may enter very dry with 2% moisture, and exit with very wet steam with high moisture content.T C said:Just for the sake of simplicity, let's consider this as a non-condensing turbine i.e. the condensation factor to be nil or negligible.
The difference is huge. What's the % of condensation that you have considered?Chestermiller said:Well, if you neglect condensation, then you end up with your value of 73.16 kJ/kg for the enthalpy change. With condensation considered, I calculate 275 kJ/kg. Don't you think that difference is significant?
9%T C said:The difference is huge. What's the % of condensation that you have considered?
Recall that I said that in comparison to power plant turbines, 250 KW is miniature.T C said:Is it the average standard rate of condensation? Whatsoever, in that case the flow rate would be go below 1 kg/sec.
The flow rate of steam in power plants varies depending on the size and type of the power plant, as well as the specific design and operating conditions. Generally, it can range from a few thousand pounds per hour to millions of pounds per hour.
The flow rate of steam in power plants is typically measured using flow meters, such as orifice meters, venturis, or ultrasonic flow meters. These devices measure the velocity of the steam and use it to calculate the flow rate.
The flow rate of steam in power plants can be affected by a variety of factors, including the temperature and pressure of the steam, the size and condition of the pipes and valves, and the efficiency of the turbines and other equipment.
The flow rate of steam is directly related to the power output of a power plant. Higher flow rates can result in higher power output, but they also require more energy to produce and can increase wear and tear on equipment. Therefore, finding the optimal flow rate is crucial for maximizing efficiency.
Power plants use a variety of control systems and equipment to regulate the flow rate of steam. This can include valves, pumps, and turbines that can adjust the flow rate based on the demand for electricity. Additionally, advanced control systems use data and algorithms to optimize the flow rate for maximum efficiency.