Project Name: Ecologization and renovation of a heating plant …€¦ · Supply and installation of technology sensors, cable trays and cables. SW design for the DCS system and visualization

Invelt holding, a.s. invelt-elektro s.r.o. INVELT SERVIS, s.r.o. INVELT ENERGO, spol. s r.o. Invelt Industry International,a.s. www.invelt.cz

Customer: C-Energy Bohemia s.r.o.

Project Name: Ecologization and renovation of a heating plant in

Planá nad Lužnicí

Scope of Supply Provided by invelt – elektro s.r.o.:

Design, manufacture and installation of the heating plant DCS system and voltage regulator

cubicles. Supply and installation of technology sensors, cable trays and cables. SW design for

the DCS system and visualization. Tests and commissioning of the technological equipment.

Short Unit Description:

At the premises of the heating plant in Planá nad Lužnicí, a new Distributed Control System was

installed and commissioned in the framework of the "Planá nad Lužnicí Heating Plant Ecologisation

and Renovation" project. This control system controls and monitors all of the newly installed

technology and the heating plant electrical systems.

The supplied DCS is designed to be connected to 5,000 signals. It has been installed into 29 fields

of seven DCS cabinets. It includes seven redundant SIMATIC PCS7 automation stations located in

individual buildings of the heating plant. It also contains two cabinets with redundant servers,

archiving server, two operator and one engineering stations, and two operator stations at the heating

plant control room. The system monitors and controls the newly installed and existing heating plant

technology consisting of four cogeneration units with 10MW gas engines and exhaust-gas boilers

(HRSG) generating steam and hot water, natural gas treatment system, hot-water heat exchange

station, five reduction and cooling stations processing technology steam, two 40 tph (t/h) coal fluid

boilers and one backup gas boiler, exhaust gas cleaning system (desulphurization), water treatment

system and other heating plant electrical systems. The system is connected to ČEPS System

Services terminal and enables the operation of the gas engines in the "Secondary power control",

"MZ5" and "MZ15" modes.

The DCS system also incorporates a closed camera system (CCTV) checking the technology. The

CCTV system consists of a cabinet with a camera server and a monitoring computer, 18 industrial

cameras and two supervision monitors with 42'' screens.

In the scope of supply, there are four cabinets of the excitation systems and voltage regulators for

the gas engine electric generators.

The control system is based on top-quality SIEMENS SIMATIC PCS7 PLCs. The PCS7 DCS

system consists of a complete set of hardware and software components providing complex

industrial automation platform. The system uses up-to-date control system technology both at the

process and operator levels. Individual technological units are controlled using automation stations

with connected I/O modules and remotely controlled and monitored from the operator stations with

visualization software. Individual system stations are connected by a redundant optical link using

Industrial Ethernet with 1 GB/s transmission speed. Important technological groups are controlled

by safety modules with verified SW.

Realization: 2013 ÷ 2015



Scope of Supply Provided by INVELT ENERGO, spol. s r.o.:

Electrical equipment together with design, manufacture, installation, tests and commissioning:

Gas engine power outlets,

Double-system 10.5kV substation with auxiliaries,

Home consumption of gas engines, HRSG and their accessories,

Systems of electrical protections, measurement, synchronization and excitation,

Electrical equipment for the exchanger and compressor stations, K4 gas boiler, K5 and K6

fluid boilers.

Cable trays, HV and LV cables, earthing.


The company delivered electrical equipment for the newly installed gas and exchanger, gas and

fluid boilers. The equipment supplies auxiliary electrical drives and other equipment of the gas

engines, boilers and their accessories (home consumption) and connects the power output of the

engines to the higher-level systems (the heating plant network and E.ON distribution network).

Home consumption of the gas engines, boilers and related technological equipment is implemented

at the 400/230V AC and 220V DC levels. Each engine and boiler have their own auxiliary cabinet.

These auxiliary cabinets are supplied from a segment switchgear which has two feeding lines from

two 6/0.42 kV transformers, 1,600 kVA, connected to different systems of the heating plant for

operational reasons. Outlets for each electrical drive of the installed technology are remotely

controlled from the control system or from the local control cabinet in case of need.

Electrical drives or equipment which requires uninterrupted power supply is connected to the UPS

cabinet using three parallel inverter units 220V DC / 400V AC. (DC voltage is supplied from the

existing redundant systems of the heating plant "rectifier + battery").


Home consumption cabinets are located in a common substation on a steel floor above the cable

chamber.

All cabling is performed in a standard way using cable canals or cable trays along the building

walls. Cable types were selected with respect to fire safety requirements (usual PVC or fire

retarding).

The existing electrical equipment was modernized or new equipment was supplied for the new K4

gas boiler, hot-water and compressor stations, electrical feeding pumps and other systems.

For the gas engine generators, new excitation system cubicles were delivered containing

synchronization systems for the generator circuit breakers.

Gas engine generators (4 times 9.38MW / 10.5kV) are connected via double-system 10.5kV / 40kA

substation with draw-out vacuum circuit breakers. In the substation, there is a spare room for future

reconnection of the existing steam turbine. The substation supports variability in the source

connection (gas engines and the steam turbine in the future) to the two three-winding 65MVA

transformers, which are connected to the higher-level 110kV E.ON system or the 6kV power grid of

the heating plant. The 10.5kV substation (located in a common substation) is connected to the three-

winding transformers using parallel single-core cables fixed to cable trays on the pipe bridges.

Electrical equipment of the K5 and K6 coal fluid boilers provides power supply for the boiler

technology from auxiliary cabinets in a similar way to the gas engine home consumption. In

addition, the boiler system contains lighting for the technology platforms.

The implemented solution enables the heating plant to supply its customers with electricity more

reliably, because there is now a second independent full-scale power source (gas engines) added to

the originally single source (E.ON). Moreover, the heating plant power network can be operated

even in island operation.

INVELT ENERGO, spol. s r.o. has delivered the electrical equipment in the turn-key form. The

Company has elaborated all project documentation, delivered equipment manufactured by the

INVELT Group® and other renowned companies, provided the installation and tests including

commissioning.





Scope of Supply Provided by INVELT SERVIS s.r.o.:

Supply of the HRSG technology, K4, K5 and K6 boilers, site management, tests and

commissioning.


Modernization of the existing K4 boiler used as a backup power source consisted of modification of

the main fuel and increasing the existing produced steam parameters. Natural gas is used as the

main fuel now. The reconstructed boiler remains a backup power source in the heating plant

operation.

The modernized K4 boiler is a stable, horizontal, overpressure, single-drum, water-pipe steam

boiler with natural circulation. The boiler carries its own weight. It is supported by a frame using

rollers. The main part of the boiler consists of the gas burner, water heater, evaporator and steam

superheater with temperature control. Burner located in the front boiler wall is a dual-block gas

burner. The evaporator consists of the burning chamber, evaporation bundle, drum and piping. The

boiler can be transported in two parts, the first unit consists of the evaporator with the superheater,

and the second one is the water heater.

K4 boiler:

Type steam, water-pipe, transportable

Designation G18,5S

Fuel natural gas

Rated steam volume 18.5 tph

Rated steam pressure 2.1 MPa

Rated steam temperature 300 °C

Inlet water temperature 105°C


Gas engine heat module is a technological unit located on the base frame. Four modules have been

supplied in total, one for each gas engine.

The purpose of the heat module is to control temperature of individual engine circuits, heat removal

from the engine cooling, and water and oil preheating. Heat from the engine unit and oil cooling is

the source of the heating power which is transmitted to the heating water system via plate

exchangers of the high-temperature (HT) circuit of the module. The HT circuit is dimensioned for

the 95/65°C temperature mode.

The module also contains the low-temperature (LT) cooling circuit removing heat from the second

stage of the filling mix cooling. This low-potential heat is transported to cooling towers via

separating exchanger. The LT circuit is dimensioned for a temperature mode with returning

temperature of 20°C.

The module also enables the operator to get rid of the excess heating power (both from the engine

and the exhaust exchanger behind the HRSG) which cannot be processed by the plant.

Heat module parameters (at rated engine power)

Rated heating power 4.05 MWt

Temperature mode 95/65°C


Heat Recovery Steam Generators HRSG 1 to 4 use the gas engine exhaust heat, and basically they

are boilers heated up by the exhaust gases. Four steam generators have been delivered. One for each

engine.

The HRSG is a stable, overpressure, single-drum, water-pipe steam boiler with natural circulation.

It consists of the water heater, evaporator and superheater with temperature regulation. The

evaporator consists of the evaporation bundle, drum and piping.

Behind the steam section (HRSG), there is a water heater heated up by the exhaust gases. The

heater's water section is incorporated into the heating water circuit. The heater has heating power of

1.274 MWt.

The boiler together with the drum and water heater consists of three installation units. All parts of

the HRSG pressurized section together with the internal exhaust gas piping and water heater are

located inside the boiler supporting frame and, therefore, represent a single compact unit.

In the scope of supply, there are HRSG walking platforms and galleries, incoming exhaust gas pipes

including the exhaust gas cleaning, by-pass exhaust gas pipes (enabling the engine operation

without HRSG), outlet exhaust gas pipes and chimneys.

HRSG Boiler:

Type steam, water-pipe, exhaust gas

Designation FG4S

Rated steam volume 4 tph





Exhaust gas cleaning system has been installed as part of the exhaust gas piping behind the engines,

and it is used to reduce NOx and CO emissions. A method based on the Selective Catalytic

Reduction (SCR) is used as a proven process of high-efficiency nitrogen oxide removal. Technical

urea is injected into the exhaust gas flow, and the nitrogen oxides are subsequently reduced to

nitrogen and oxide in the catalytic converter. The exhaust gas cleaning system also contains a

metallic catalytic screen reducing the CO emissions.

Reduction parameters (at 15% O2)

Nitrogen oxides (NOx) 75mg//Nm3

Carbon monoxide (CO) 100mg/Nm3


In the framework of the coal power plant modernization, the K5 and K6 coal boilers have replaced

the out-of-date existing pulverized coal-fired boilers K2 and K3, representing the basic heating

source of the heating plant. Both new boilers have the same design. The main fuel is brown coal.

Natural gas is used for the boiler start.

K5 and K6 boilers are fluid, single-drum, vertical, underpressure, four-draft steam boilers with

natural circulation. Each consists of the water heater (economizer), evaporator and steam

superheater with temperature regulation. The boiler is not equipped with an air heater, because

unheated burning air has positive effect on emissions. Higher temperatures of the exhaust gas dew

point caused by larger sulphur content have also been taken into consideration. Boiler regulation is

fully automatic, and the boiler power can be smoothly controlled in the whole operational range.

The boilers meet the required NOx emission limits using primary measures; secondary measures

have, therefore, not been used.

The coal burning process is based on the INVELT FLUID system which is using burning in a

fountain fluid layer supplied with the primary air through a small stationary grate. This technology

fully complies with BAT requirements and ensures that required parameters will be obtained. The

technology has low consumption of materials and energy, it can reduce the capital and operational

costs, mainly maintenance costs.

Gasification and partial burning of the fuel happens in two fluid reactors located in the lower part of

the burning chamber. Primary air and fuel are supplied into the reactors. Above the reactors, along

the height of the burning chamber there are nozzles of the secondary, tertiary and burn-out burning

air used for the burnout of flammable gases and flue dust (from the fluid layer).

In the burning chamber, there are two start-up monoblock gas burners and heat radiation steam

superheater. Exhaust gases from the burning chamber subsequently enter the second draft. In its

lower part, there is a grille separator separating the fly ash solid particles. Separated fly ash is

returned to the boiler reactors. The grille separator is thus used as the fluid boiler cyclone increasing

its overall efficiency. In the third draft, there are four steam superheating blocks. In the fourth one,

there are five water heating blocks. All blocks in the third and fourth drafts are convective and

designed to limit their abrasion and aggradation.

The pressurized section consists of a double feeding head, temperature regulation system for water

before the economizer, water heater blocks, drum, evaporator membrane walls, and superheater

blocks (convective and radiating) with two-stage temperature regulation for the inlet steam. Water

flow is regulated to maintain the required water temperature at the water heater inlet depending on

the amount of SOx in the exhaust gases. This measure prevents water condensation contained in the

exhaust gases on the surface of the water heater inlet pipes caused by the higher exhaust gas dew

point influenced by the higher sulphur content in the fuel. Water flows through the water heater

blocks (consisting of the coiled tubing) to the drum. The drum and the membrane walls form the

evaporator. The membrane walls form the burning chamber, second and third drafts of the boiler.

Steam-water mix created in the evaporator is returned to the drum. There are internal walls in the

drum ensuring the required conductibility of the outlet saturated steam. The steam goes to the

superheater inlet section. The convective superheater blocks consist of coiled tubing bundles.

Superheating is controlled by the supply water injection. The steam flows through the radiating

superheater and continues through the boiler outlet chamber to the steam piping.


The boiler is partially carried and partially suspended on a supporting frame manufactured from

rolled profiles. Boiler maintenance platforms and galleries are attached to the supporting frame.

In the scope of supply for the boiler modernization, there is a design and supply of fuel transport

from the coal bunkers and fly ash removal from the fluid layer by cooled conveyer screws.

K5 and K6 boilers:

Type steam, water-pipe, fluid

Designation G40S

Fuel brown coal (natural gas for start-up and stabilization)

Rated steam volume 40 tph





Documents

Project Name: Ecologization and renovation of a heating plant …€¦ · Supply and installation of technology sensors, cable trays and cables. SW design for the DCS system and visualization