Pressure adjustment in city distribution network

[CostasV]

In a typical city distribution network, the pressure is kept almost constant at the pressure set point, lets say at 8 bar(g).

I have recently heard that if the pressure set point is adjusted (and thus the pressure in the network), for example it is increased to 12 bar(g), or decreased to 6 bar(g), remotely, and the same time monitoring and keeping the gas supply flow rate into an acceptable range, there could be some benefits to the network operator.

Do you know if there exists any such distribution network ? Could you tell me if you can think of any potential benefits with pressure adjustment?

 

[CostasV]

Any feedback?

 

[MortenA]

I dont think your question makes much sence. It seem to me that you have your own system very much in mind and thus it is not possible to understand what you are aiming at because we dont know your system.

Vedry general questions often dont get much feedback - or gets derailed on this site - because we dont offer "free consultancy services"

Best regards

Morten

 

[CostasV]

Let me clarify the question, and de-generalise it.

We have a city distribution network made of steel pipes of 10", length about 100 km, and design pressure 19 bar (g). This network feeds the big customers of the city area as well as the PE distribution network that feeds the smaller customers.

I have worked only with gas networks that keep a constant pressure.

Can it be, or does anyone know, of a city distribution network like the above mentioned, that adjusts its pressure on a daily or perhaps weekly base, for example between 6 bar(g) and 12 bar (g), for some (I really can't think any other) economic benefit to the operator?

By having the network pressure increased or decreased, the network can be used as a gas reservoir of about 5000 m3. Roughly 30.000 ?m3 of gas, if the fluctuation of pressure is 12-6=6 bar.

If the average gas flow rate is about 200.000 ?m3/day, and if there is a pricing policy that (as all pricing policies do) try to keep the demand as constant as possible, do you think that the pressure adjustment is the solution? Or is it just a bad idea?

Or is there some other (not economic) reason to have such pressure adjustment?

My question is: does anyone know of a such or similar network operation philosophy that actually works? I would like to hear the operator's experience.

 

[MortenA]

Sorry no - i dont see the point either. The volume seems to small for "line packing". The effect will of course occur "naturally" to some degree but as a strategy i dont know.

Best regards
Morten

 

[CostasV]

I agree. But I wanted a second thought.
Thanks.

 

[vzeos]

Varsamidis:

It depends on the load variation your system experiences. In some areas that have high gas usage for space heating in the winter, the system operators will raise regulator pressures in anticipation of the higher load. This is usually done seasonally for manually operated regulators or it can be done daily with remotely controlled regulators. The reason for raising the regulator pressure is to create a greater pressure differential between the regulator and the gas utilization points. The greater differential forces more gas through the pipe effectively increasing the pipe capacity. During summer load periods the regulator pressures should be maintained as low as possible.