Refurbishment of
central heat supply systems
Veselí nad Lužnici
DESCRIPTION
Over time, two central heat supply systems (CHSS) associated
with the development of urban panel-housing units were built in
Veselí nad Lužnicí. These two systems were basically
independent of each other without the option to interconnect due to
their technical design and location within the territory - the
hot-water coal-based heating plant called "U
zastávky" is in the southern part of the territory while
the steam coal-based heating plant called
"Jateční" is in the north-east of the
territory.
In the period of 1999 - 2003, the City carried out a fundamental
refurbishment of these central heating supply systems.
Blatské housing area
The original central
heating plant that supplied the Blatské housing area had the
installed capacity of 14.8 MW and was fitted with three steam
boilers: It supplied heating steam via a primary steam line, which
was 1.9 km long, to two heat exchange stations VS 1 and VS2. These
exchange stations transformed steam to hot water and supplied the
heat and hot water through a four-line system to end-users. The
entire system showed excessively high losses both on the source and
in the distribution system and exchangers. The operator specified
combustion efficiency (energy conversion rate) of 70% for winter
and 60% for summer seasons. The primary steam line losses would
oscillate around 60% in the course of the entire year. Annual
electricity consumption in the Jateční boiler plant was
475.132 MWH, and brown coal consumption was 5,003 tons. The annual
heat output at the plant discharge was 60,746 GJ, while the heat
input at the heat exchange station was 43,282 GJ.
The Blatské
Central Heat Supply System has been in continuous operation since
1999. Its refurbishment consisted of building a new, up-to-date
heating source in the existing heat-exchange station VS 1 -
Blatské housing area, and of eliminating the steam line from
Jateční coal heating plant. The new heating plant is
provided with gas hot water boilers with the combined capacity of
7.2 MW and a 150 kWe co-generation unit. The heating plant control
system is Johnson Controls.
Simultaneously, peripheral parts of the secondary heat distribution
four-line system were renovated to two-line system with
decentralized generation of hot water in the buildings, which are
fitted with pressure-dependent delivery stations, and gradually,
the heating radiators of all end-users were fitted with
thermostatic valves. For a large part however, the four-line
distribution systems are still in operation. The Municipality
intends to complete the refurbishment of distribution systems
originating from the previous CHSS.
The Blatské CHSS supplies heat to multi-dwelling buildings -
505 apartments, as well as community facilities such as the
elementary school, house of culture, municipal building, elementary
school of arts, etc.
Zastávka Central Heat Supply System
Zastávka CHSS was
build in 1972 and was designed to supply a newly built panel
housing development called "U zastávky", including
its community facilities. The installed capacity of the source was
9.65 MW.
The new Central Heat Supply System retained the original concept of
brown coal hot-water boiler plant but the heat production was to
become more environment-friendly; the incineration process and
precipitators in two original boilers of V 2500 U type from 1989
were adapted; other two original boilers (Slatina V135/105 and
Vihorlat Snina) were outdated in terms of operation. Hot water was
produced centrally in four vertical hot-water heaters of 10 cubic
meters of unit volume, 25 sq.m. hot water heating element and
four-line heat distribution system.
The Central Heating Supply System was divided to two phases: the
first one concerned the adaptation of the source part - the two
original hot-water boilers burning brown coal remained, of which
one serves as a backup, and also a new gas hot-water boiler of 2.1
MW in heating capacity and a 22 kWe and 45.5 kWt co-generation unit
were installed. The second phase attended to the distribution part
- the four-line distribution was replaced by a two-line system.
Pressure-dependent delivery stations were built in individual
buildings, with heating water temperature control and decentralized
production of hot water directly in the buildings. The heating
plant control system is Johnson Controls.
The Zastávka Central Heat Supply System supplies heat to
multi-dwelling buildings - 548 apartments, as well as community
facilities such as the kindergarten, special school, St. Francis
Charity Building and others.
Climatic data:
The area in question falls into the B climatic area -
temperate warm - and climatic zone B3 - temperate warm, moderately
humid with slight winters, upland. The calculated value as per
standard ČSN 060210 is -15°C. Western winds prevail.
During periods of inversions that occur quite frequently due to a
high rate of water planes within the territory pollutant levels
rise in the atmosphere ground-level layers.
Average yearly temperature: 7.4 °C
Elevation: 429 above sea level
Average monthly temperatures:
Month 1 2 3 4 5 6 7 8 9 10 11 12
Average air temperatures (°C) -3.3 -1.7 2.0 7.6 12.3 15.4 17.2
16.1 12.5 7.0 2.6 -1.4
Partnership process:
The present heating system in Veselí nad Lužnicí
makes for one of the most advanced heating systems in the
South-Bohemian Region. The project was funded with the
participation of the National Fund for the Environment and Czech
Energy Agency. The Center for the effective utilization of energy
SEVEn in cooperation with K-project company prepared the technical
solution including drawing documentation. The actual project was
implemented by STRABAG České Budějovice and ERDING
a.s. Brno companies. Primary contractors for technology were TH
Ratíškovice and LOOS (hot water boilers), TEDOM
(co-generation units) and Johnson Controls (instrumentation and
control).
Zastávka Central Heat Supply System
- Sigma Slatina Coal hot water boiler of 2.91 MW heating capacity
- LOOS Gas hot water boiler of 2.1 MW heating capacity
- TEDOM Premi 22 AP Cogeneration unit of 22 kWe and 45,5 kWt capacity.
- TH Ratíškovice hot water boilers of 3x 2.4 MW capacity
TEDOM Cento 150 SP cogeneration unit of 150 kWe and 226 kWt
capacity
Technical data:
Fuel and power flows within the Central centralized heat
distribution system are displayed on the Sankey´s diagram
before and after upgrade.
COST & BENEFIT
Economical
The municipal heating system was refurbished based on technical
documentation made by the SEVEn company. The refurbishment
progressed in several phases; it started in 1999 and the last
modifications took place in 2003. The total cost of the project
implementation was CZK 35,135.86 thousand, of which Czech Energy
Agency subsidy was CZK 2,700 thousand and National Fund for the
Environment subsidy was CZK 3,340.8 thousand.
Total savings, including cost of fuel and energies, payrolls,
servicing and maintenance, other services, atmospheric pollution
fees, etc. are CZK 1.8 million per year. Simple savings return is
16 years.
Environmental
The primary pollutant emissions were on average reduced by 73% and
CO2 emissions by 68%. The eminent reduction in primary pollutants
and CO2 emissions was the result of changing the fuel base
(transition from brown coal to natural gas), installation of a
technology with high heat production efficiency, installation of
cogeneration units in both systems and the renovation of
distribution systems, which resulted in cutting down the
distribution losses.
CONTACT DETAILS
Organisation:
SEVEn, The Energy Efficiency Center, o.p.s.
Address:
Zizkova 12, Ceske Budejovice 370 01, Czech Republic
Tel: +420 386 350 443
Fax: +420 386 350 370
E-mail: seven@svn.cz