CHP with gas turbine bsaed

[Bhatsantosh]

Hi everyone. this is my first post.
I have been working upon designing Combined Heat Power system with Gas turbine running on natural gas. By taking any industrial scenario generating steam, hot water and using electrical chiller for cooling purposes in the workstations. We want to propose to install a single Gas turbine based CHP which can cater the needs of electrical supply, thermal supply of steam through hot flue gas, and hot water need by gas turbine jacket water used for cooling engine, and finally chilled water production for VAM machine. How to find out for what scenario CHP will be best applicable. For example some industries may be having steam and hot water need but may not be chilled water need. So we can propose gas turbine based CHP which caters the need of only steam water, hot water and electricity.
How to understand which scenario will be better for installing CHP????

Also in gas turbine what is the usual % of losses? usually electrical output will be 35-40%. Where ans all other energy is getting wasted including flue gas, coolant etc. What is the usual % distribution???

Plz give me proper understanding

 

[davefitz]

bhatsantosh;

The use of a gas turbine in a combined cycle with or without cogeneration is common, and is technically modeled by computer programs such as GT-Pro/ Thermoflex. The objective is to maximize the rate of return on investment, so the economic parameters of capital cost, cost of money , and cost of fuel are fundamental to the optimization model. Now , the cost of water also plays a role in most areas.

The fuel cost varies widely , whether it is US frack gas, Russian -European gas, or imported LNG , by a factor of 5:1 at current prices, so the optimum design varies according to the location. Also, one needs to consider alternative energy investments, as there are claims that solar PV will be less costly over time than a gas fired combined cycle plant in most locales- if you neglect to evaluate alternative energy technologies, you may be stuck with a useless plant , as had happened in western Europe in the last 2 years.

"Whom the gods would destroy, they first make mad "

 

[Pederator]

"if you neglect to evaluate alternative energy technologies, you may be stuck with a useless plant , as had happened in western Europe in the last 2 years"
Can you please expand and clarify this sentence? I live in western europe, and I am curious what are you exactly talk about.

 

[Pederator]

Sorry, I live in eastern europe. But it still interests me.

 

[racookpe1978]

That far north, in that cloudy a location, solar PV will not pay off.

 

[EdStainless]

A simple cycle GT just generating electricity will be 25-35% eff depending on size (larger is more eff).
The huge machines can reach 40%.
Using the exhaust to make steam, and then spinning a steam turbine will get you to 55-60% total.
Just using the steam directly is more efficient.
There are commercial examples of ammonia chiller plants being run off of the waste heat from GTs.
The real problems involve the infrastructure needed, water demands for cooling, and skilled operator for reliable service.
Assuming that the capital investment required is not the stumbling block.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[Bhatsantosh]

Thank you davefitz for important insight. Basically this project belongs to southern part of india, where the industries use furnace oil or any other related oil as fuel. We want to have a case study which energy solution will be best suitable and increases the energy efficiency and reduces the total annual cost. One of the alternative we thought about is Cogeneration. Although solar PV etc. are springing into market but not much technology has come up in this current environment. Best we thought about is cogeneration, now question is which type...... whether gas turbine based, or steam turbine based or DG based........... In what way Gas turbine is better that other type???
Compared to other fuels in this scenario natural gas is available at reasonable price. Even raw materials like water etc. are quite cheap as well.

Problem what iam facing is iam not able to get proper details regarding wastages which occurs in turbine which can be utilized to increase total efficiency of the system. Turbine produces steam which can be used for producing steam and for processing. Also there is coolant water needed to cool the turbine, which may be low grade heat, but can be used for producing hot water for some processes. So what % heat gets carried by the fluegas and coolant water, and radiation etc.....(if there are any more sources of heat dissipation)........ Taking a standard gas turbine or steam turbine, a crude range of % is sufficient

Plz guide me

 

[racookpe1978]

You cannot "wrap" a gas turbine pressure vessel - which is what the GT casing actually is - with a cooling water system because of the continued need for maintenance access and the dozens and dozens of gas supply, control air, instrument and thermocouples, cooling air, and recycle air connections that will interfere with the proposed water-cooler.

Best to just thoroughly dry-insulate the GT casing and use the combined cycle steam generator heat exchanger. And those have enough maintenance issues to require work each shutdown period.


Thus, trying to get a little bit of 150 to 180 degree water by building an incredibly complex water-wrapped cooling network, added pumps, controllers, heat exchangers, and tanks around a gas turbine casing that must be split in two every 18 months isn't effective.

 

[GHartmann]

You have quite a feasibility study on your hands. I am not sure you will be able to do this independently without the use of a experienced "consultant" in the industry.

You really need to define some level of scale for each of the "energies" produced. I am by no means an expert, but your hot water circuit could be possibly integrated into the HRSG component of a combined cycle plant.

Here is a link to some GE Gas turbines showing capacity ranges:

GE Gas Turbines

Just to add more complexity to your study these turbines can be adapted to use a variety of liquid fuels (think airplane jet engine or marine propulsion system)

Good luck

 

[GHartmann]

Here is a basic guide on the subject.

 

[davefitz]

Pederator;
<

http://www.greentechmedia.com/artic...20gw-of-gas-plants-in-2013-with-more-to-come>

The major electric utilities of western Europe have mothballed over 40 GWe of brand new gas fired combined cycle plants in the last 2 yrs, and have reported drastically reduced earnings , as the direct result of not considering the impact of widespread use of solar PV and wind energy production . It is estimated the total capacity of the fleet to be mothballed is 117 GWe by 2017. E-ON!, Suez, Panda energy, RWE have serious financial issues related to European earnings . E-On! proposes to unbolt new gas fired combined cycle plant components from their original European foundations, truck them to Turkey ,and rebuild the complete plants in Turkey.

Apparently , the MBA's that made the business investment decisions that led to building 117 MWe of unneeded gas fired combined cycle plants were using very sophisticated economic models that , unfortunately, had no basis in modern reality. But, at least they were sophisticated. An alternate interpretation is that the European business/ government relationship was biased toward empowering organic persons ( eg ,individual human beings) as opposed to corporate "persons", and when situations change, the less powerful pay the price. . It is clear that the US power industry will not allow that sort of devolution to occur in the US.


Of course, as in real estate, location is everything. The "perfect storm " that occurred in Europe involved very expensive Russian natural gas, runback in gas output from the north sea, regulations that preference power from "green " sources, greatly reduced costs for solar PV from China, and tremendous popular support for personal investments in rooftop PV. The tax incnetives in Spain ( which were retroactively eliminated ) played a big role as well.

"Whom the gods would destroy, they first make mad "