Gas Expansion Turbine Generator

[templar113]

Hi Everyone,

We have a number of pressure reduction stations in our Natural Gas distribution network. Inlet pressures of around 3.8 mPa are cut down to around 1.9 mPa by the pressure reduction station using throttle valves.

I am currently investigating the use of Expansion Turbines in place of the throttle valves. The flow and expansion of the gas due to the pressure drop drives a turbine and in turn generates electrical power.

One issue is that the inlet pressure is only about double the outlet pressure. The second issue is the flow through these pressure reduction stations is only between 10-20,000 Sm^3/h.

The kinds of products that I found so far, require flows above say 50,000 Sm^3/h and pressure drop ratios of 4-10. I expect that with a ratio of 2 and a flow of 10-20,000 Sm^3/h it would only be possible to get between 100-500kW of power.


My questions are:

1. Can anyone confirm my comments regarding generating ability given my limits?

2. Has anyone out there used smaller expansion turbines to generate electricity? What was your experience?

3. Did you have to deal with surplus power storage? Regulating the power output in response to the demand? How was that achieved?

 

[7anoter4]

It is a very interesting issue, indeed. But it seems to me is more a thermo-mechanical problem rather than electrical one. It seems the Prague Institute of Chemical Technology did a simulation as described in the following article in 2004.I don't see any attempt to produce electricity this way in Gas Turbine field.
See:

http://actamont.tuke.sk/pdf/2004/n3/27pozivil2.pdf

Try to present the problem in Eng-Tips
Heat Transfer & Thermodynamics engineering Forum

 

[rasevskii]

The company ABB-Energie of Gent in Belgium was active in gas-expander turbines for the gas network in Belgium. When they closed down their factory in Gent in the mid 90s the business was taken over by Atlas-Copco. What happened to that afterwards, I do not know.

regards, rasevskii