FAQ about the design, construction and launch of power centers in Russia

Cogeneration gas piston unit of shop version with rated electric power - 1 MW. Nizhny Novgorod region, Bor


The appearance of the power center, Nizhny Novgorod region, Bor. Nominal electric power of the power center is 3.6 MW, thermal power is 14 MW

The year before last, I wrote about energy centers. During this time we have passed several more objects, in particular, now at a different stage of development there are 3 objects. Somewhere it is completely entire projects, somewhere - separate nodes. The demand for power centers is now in full swing, and our team is just bombarded with questions. Therefore, here is the FAQ below.
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- In a nutshell, what are these energy centers?
Autonomous mini-power plant running on gas or other fuel. Like any generator, it generates a certain amount of heat, which is used for heating the object and other tasks. In the summer, heat can be not discharged into the atmosphere, but disposed of through an absorption chiller, which provides a resource for data center cooling systems and air conditioning of the same shopping centers. The energy center is able to produce electricity, heat and cold.

- Is there an example of an object?
Yes please. For example, we are currently working on an energy center for the data center and several administrative buildings in Vladikavkaz. All this needs is electricity, warmth and cold. They are located on the outskirts of the city and bring there electric and heat networks is expensive and long, and the gas has already been conducted. It was decided to build its own energy center. It is small in power - 3 megawatts of electrical power and 1.6 megawatts of heat and cold. The cold is necessary for central air conditioning of the room and for supplying to the main building of the data center, and the heat for hot water supply and heating is a fairly common situation.

- And remind what is cogeneration?
The cogeneration unit generates electric and thermal energy simultaneously. The efficiency of using fuel resources in cogeneration units is 30–40% higher than in the case of separate production of electricity and heat.

- A trigeneration?
Trigeneration is also the production of cold. Cogeneration plants are equipped with heat exchangers, utilizing heat generated during engine operation. This heat can be used for technological purposes (including for steam production), for heating and hot water supply. Excess heat can be absorbed in order to obtain chilled water. In general, it is water that is submerged up to 5 degrees Celsius, ideal for air conditioning systems of the same shopping centers, office and public buildings, and data centers.

- Is trigeneration always used?
No not always. The energy center can produce several types of energy resources: electricity, heat, cold, steam and CO. Depending on the tasks on a particular object. Sometimes you only need power, sometimes - all at once. The use of several energy sources increases the overall efficiency of the energy center. For example, in the Nizhny Novgorod region there is a commercial energy center in a field on the banks of the Volga. It produces electricity and heat. Electricity is supplied both to direct consumers (by direct contract) and to the network at a protected tariff. Heat is supplied to the nearest village on its own heating main.

- Is there an example of an object where only a part of the power center is being made?
For example, we are doing for one shopping center just a boiler room and gas supply infrastructure. This is the simplest example. Sometimes we only do transport infrastructure for fuel and so on - there is a lot of different work.

Here is a card of one of the objects:

• Type of construction - new construction.
• The location of the construction site is Bor, Nizhny Novgorod Region.
• Staged construction - 3 stages (CROC participated in the implementation of only the second stage).
• Purpose - the sale of electricity to the external network, and heat supply facilities of the municipal sphere of the village Oktyabrsky, Borsky district.
• The reason is the creation of a commercial Energy Center for the sale of energy resources in the retail energy supply market to external consumers.
• Rated capacity of the second stage - electric power 1.6 MW; thermal power - 1.8 MW.
• Execution of CHP - shop.
• The equipment of the second stage - KSU - MTU (Germany).
• Payback period - 3 years

- Who needs such energy centers in Russia?

• For data centers, for them their own power center is both savings and the opportunity to get another supply / cooling vector.
• Industrial enterprises, most often - either new or reconstructed. Here is just a matter of saving.
• Farmers and housing estates, as well as various logistics facilities that consume from 1 to 50 MW of electrical capacity - here autonomy comes in first place.
• Shopping centers: like data centers, they are an ideal “client” for the power center, as they use energy, heat and cold.

- How does AbHM work for the production of cold?
This is such a healthy cast iron apparatus in the size of half a flat. There are complex chemical processes based on lithium-bromine solution, constant evaporation, condensation, in three cycles. As a result, at the entrance you give hot water, and at the exit you get chilled. There are details on Wikipedia.

- What is the difference between turbine power centers and gas pistons?
The type of engine that drives the generator. A piston is like an internal combustion engine in a car, a turbine is like in an airplane. Capacities up to 50 MW are more convenient to close by piston engines. Those that are 50 Megawatts and more, this is a big energy discharge, that's where the turbine is. But the choice is not only in power, but also in the selection mode.


Element piston power center. In the upper part there is an air manifold with a filter, in the lower part there is a system of cylinder blocks.

- What is power take mode?
The turbine “accelerates” for a rather long time in order to enter the regime. For example, in Moscow, at CHP 21 and 24 there are almost the same Siemens turbines at 300 MW, as at Boeing (only more and with some design differences). To fully enter the mode, you need from 20 to 25 minutes. If the power jumps constantly, two situations can arise: when one of the turbines is not turned on (and its resource is very necessary) and when the turbines are turned on more than necessary (in this case we will warm the atmosphere). The gas piston machines have a shorter time to reach the mode - 5-7 minutes. In practice, objects of more than 50 megawatts in our segment of data centers and shopping centers are almost absent, so we mainly use gas piston units.


The appearance of the gas piston unit MTU


GPU dry cooling tower system

- What happens when consumption jumps?
The first energy centers, built almost at the time of the country's electrification, had a difficult balancing. Modern make everything onboard, like the same car engine. When you turn on the music in the car, the headlights do not blink - so here, the internal adjustment system of the generator instantly reacts to changes in the consumed current, adjusts the output power so that all consumers are fed without any deviations in quality and frequency. To date, this technology is well developed. Usually, a large number of controllers are installed in power centers: on the gas unit itself, at KGU, roughly speaking, on an engine with an attached generator. The load changes all the time depending on external customers. The controller controls power, crankshaft speed, fuel supply and all engine modes to stabilize output parameters.

So, one of the parameters is the step of charging and dumping electric power - a question of the design decision depending on the needs of the customer. For some consumers, for example, for powering data centers with electricity, a sharp increase in capacity is very important, for others, for example, for industrial enterprises, 10% -15% of the nominal capacity of the installation per minute is acceptable. For example, for typical consumption of a 2-4 MW shopping center, it is possible to use a hcp, but it is important that the power surge is not more than 20% of the rated power per minute. For illustration, on average, the standard pitch of the power transfer to the GPU is 15–20%, and the GTU is lower. But even if the power increment step at the installation is insufficient for the consumer, this can be corrected, for example, by storing the external network (at the initial stage, the power will be taken additionally from the network), or by combining with uninterrupted power supply sources or installing a soft start system on the consumer side , or setting the controller in this way. All these options for the development of transients are individual for the object and can be taken into account at the design stage.


Schematic diagram of the management of the issuance of electrical power

- How is the heat removed from the engine?
The engine is hung with heat exchangers, there are many different schemes. Heat is removed from the shirt, from the intercooler, from the exhaust and so on. In general, everything that would otherwise go to the atmosphere goes to consumers of heat.


External heat recovery unit

- What about exhaust?
They are formed in the same way as when a conventional engine is operating in a car. We use American or European equipment. Natural gas is a relatively clean fuel. The content of harmful impurities in the exhaust corresponds to half or even one-quarter of the German standard TA-luft, which in turn is much tougher than Russian standards. Often in an urban environment, the existing high background does not allow measurements of our exhaust.

- And what about the ecology of energy generators?
Ecological consequences are in any generation. Hydroelectricity influences nature through changes in the level and direction of rivers. Atomic is known for emissions and the need to bury / reprocess spent fuel. Clean solar and geothermal energy, but its use is limited. The gas generation we use is significantly cleaner than coal-fired CHP plants.

- What is the usual cost of production of resources in its energy center?
Depends on the details of a specific object. In general, it is 1.5-2 times lower than the tariffs of local energy retail companies. In our practice, the annual savings from the introduction of a local energy center is 25–30% (compared to the use of resources of a power sales company).

- Is it possible to commission capacity in stages?
Yes, and it is very convenient when it is necessary to distribute investments for 1-2 years: the commissioning of capacities is done in stages as the need for them grows. But, of course, in good hands, in those hands that are able to organize the process of operation, any energy center, even a poorly designed one, will work well and the costs will be constantly low for operation. And, on the contrary, it is possible to make a power center well, but to give it to crooked hands, then due to the human factor the costs will constantly grow, and ultimately they can kill the whole business. This is a human factor, it is a factor in the organization of the process of exploitation. The last cavity of our project (mentioned in Vladikavkaz) is done quite neatly and conveniently for operation. The maintenance of the normal operation of the suitability of this complex and the carrying out of regular maintenance work is handled by a minimum number of people. Now there is always only one person present at the facility - the dispatcher.

- When is MOT done?
On standard units - every 2000 hours. In practice, this inspection is 1-2 engineers 4 times a year. Sometimes we do it, but more often - operational customer teams.

- What kind of fuel can I use?
Natural gas, biogas from woodworking wastes and livestock farms, biogas from sewage treatment plants and waste treatment plants, coal, fuel pellets. In my practice, 98% of the energy centers run on natural gas.

- The price of gas is not fixed: if the tariffs for electricity grow, can it also grow?
The growth rates of electricity and gas tariffs may vary, but the plug between them will always be about the same, since electricity is a product of gas. The final product is always more expensive than raw materials.

- What is most often asked before ordering?
Approximately 20% of the time I’m called by process engineers and asked specific technical questions. In the remaining 80% of cases, the questions relate to financial and temporal indicators: how to get an internal rate of return of 30% (easy), how much does a certain energy center cost in a certain area with such a power, what area is needed for building, how long does it take how much our gas pipe will cost in our practice and so on. Accordingly, since there are a lot of such calls, we made a special calculator. It is approximate, but it gives an excellent idea of ​​how much that will cost for the data center or the shopping center. If you understand finance and have already read the FAQ above, you can easily see the parameters of your power center - namely, estimate whether it is worth building or not, understand the order of costs. Then I can help with the experience and calculations.

UPD : not habrazhiteli send me questions in the mail, some, I think, will be interesting to all. They are below.

- What is the approximate efficiency provided by the piston installation when working on gas and generating heat and electricity?
Up to 43% electric, up to 50% heat. Up to 93% in total.

- You write that power up to 50 MW is more convenient to close with the described installations, in reality there are a huge number of GTPPs with a capacity from 10 to 50 MW. Why is it more convenient? It means that the GPU is more convenient than the GTU.
Cheaper and the cost of equipment and operation.

- How many personnel are required for maintenance and control of an installation with a capacity of ~ 25 MW?
It is necessary to separate operational and maintenance personnel. At least 2 people are usually at the station around the clock, while at the same time, up to 6-7 people can work during the day shift. Maintenance is carried out by contractors, the number of personnel is approximately from 1 to 3 people depending on the complexity of the work performed.

- How long do the PP2000 last?
From 6 to 8 hours, taking into account the cooling time of the equipment

- You write that the time for a full-fledged exit to the nominal mode of a gas turbine unit takes 20-25 minutes. In fact, from the hot standby state (the circuit is assembled, the rotor does not rotate) a time of about 12 minutes is a complete cycle with all the warm-ups and output to the nominal, in an emergency the time is ~ 4 minutes. If the GTU does not work at the nominal, then the rate of load increase strongly depends on the type of engine, if the engine is aviation, then with a 10% load on the nominal ~ 5 seconds, the ship naturally lasts longer.
GTU consider energy. Their inertia is much higher than the GPU.

- And another question, on what is the ASUiR installation implemented?
Fundamentally ASUiR built on controllers, which determines the supplier of equipment, most often use controllers Siemens and ComAp.

Calculator here .
Last post with a card for the construction of one of the objects in 2012 and photographs.

With pleasure I will answer your questions here in the comments or by mail dmarkin@croc.ru .