Steam Turbo-generators
Steam Turbo-generators
(OP)
Hi,
My company has recently discovered the potential benefits of replacing pressure reducing valves (PRV) on the steam line with steam turbo-generators. We approached a supplier to assess the potential for generating electricity in our steam system.
With the information we gave them, they gave us a summary of how much electricity we could produce. My company wants me to verify the figures that were presented to us.
Can anyone help me with the calculation to determine the energy available for conversion, given the inlet and outlet pressure and steam flowrate through the PRV.
Thanks.
My company has recently discovered the potential benefits of replacing pressure reducing valves (PRV) on the steam line with steam turbo-generators. We approached a supplier to assess the potential for generating electricity in our steam system.
With the information we gave them, they gave us a summary of how much electricity we could produce. My company wants me to verify the figures that were presented to us.
Can anyone help me with the calculation to determine the energy available for conversion, given the inlet and outlet pressure and steam flowrate through the PRV.
Thanks.





RE: Steam Turbo-generators
Some comments:
- Give us the the inlet and outlet pressure and steam flowrate through the PRV.
- How many hours per year will the steam turbine be in use ?
- This type of equipment requires regular maintenance and, sometimes, an operator (in many US states). This strongly affects the ROI
- You might want to consult an engineering firm for a conceptual price/cost estimate. Frequently, there must be an upgrade to foundations, structures, piping and electrical systems with such an extensive change
-MJC
RE: Steam Turbo-generators
There is no feee energy.
RE: Steam Turbo-generators
Inlet P = 1300kPa (gauge)
Outlet P = 385kPa (gauge)
Ave q = 20 tph
Hours/yr = 8400
DCasto,
We currently have PRV's in the steam line where this energy is lost.
RE: Steam Turbo-generators
Assuming an inlet pressure of 1300kPa of saturated steam, you will develop approx 3400 Kw, if you use a condensing type turbine.
You do not supply the available steam temperature,which if superheated will increase your power capability.
Saturated steam to a turbine will erode the turbine blades prematurely.
Offshore Engineering&Design
RE: Steam Turbo-generators
RE: Steam Turbo-generators
Usually, a backpressure (not condensing)turbine with a controlled bypass is the most attractive in these installations... but your point about erosion due to saturated steam is well taken.
The addition of a turbine to an existing steam system is always difficult and having a steam system originally designed with some superheat is always best.
While a condensing turbine is certainly possible in such situations, you quickly get into more equipment maintenance requirements and cost of manpower that make any installation < ~ 5 MWe suspect.
-MJC
RE: Steam Turbo-generators
There is an extraction of mechanical energy that can be gained here while still using the latent heat of the exhaust steam
Wood and bagass plants have been doing this for nearly 100 years now.....
My MIT friends in Massachusetts have been earning a living providing packaged systems for many years.
See these links:
http://w
http://www.nestco1.com/index.htm
http://www.nrel.gov/docs/fy02osti/31155.pdf
Please tell us where you are located and your final choice of equipment
-MJC
RE: Steam Turbo-generators
My thermodynamics teacher and friends have been doing this in refineries for 100 years and we balance our steam turbines with electric pumps to get a balance all the time. We turn off the steam turbines because we can make electricity cheaper or we need that steam energy more as heat than power.
RE: Steam Turbo-generators
I appreciate your point, but currently my country (South Africa) is going through a power supply crisis and is forcing industries to reduce electricity usage/dependance by 10%.
Although the energy can be used to heat something, an electricity reducing/generating initative carries more weight at the moment.
Thanks.
axx1
RE: Steam Turbo-generators