DISTRICT HEATING SYSTEMS
District heating (DH) systems are а potentially energy efficient and cost-effective way to supply heat and hot water, and have been used for decades in Central and Eastern Europe and the NIS. In Western countries, the use of district heating systems, especially combined heat and power generation, is on the rise. Unfortunately, due largely to the lack of maintenance and capital repairs in recent years, DH systems in Ukraine are plagued by inefficiency and excessive distribution losses. DH systems in Ukraine are а significant source of the greenhouse gas emissions. They account for 20% of the CO2 and 81% of the methane emissions produced by fossil fuel combustion.
District Heating Systems in Ukraine
Ukraines 70,000 high-rise residential buildings (five or more stories) alone consume approximately 40% of all of the countrys heat energy resources. Collectively, Ukraines DH systems consume about 8.1 million metric tons (MMT) of coal equivalent each year, including 7.7 MMT of gas, 0.3 MMT of oil and 0.1 MMT of coal. Accordingly, the Ukrainian Government is seeking ways to improve the efficiency of DH systems. Achieving this goal could result in enormous energy savings and reductions in greenhouse gas emissions.
Source: Ministry of Ecology. National Inventory of Anthropogenic GHG Emissions and GHG Absorption. 1998
Improving the Efficiency of District Heating Systems
The efficiency of а DH system depends on the effective functioning of each of its components:
- production of heat by DH boilers
- distribution through the network of pipes, and
- consumption in Dh-heated buildings
Losses associated with heat production can reach 30% -- а much higher figure than should be possible to achieve using existing technology. Reducing production losses could improve efficiency by 10% to 12% in newer boilers and up to 35% in older ones.
Methods to Improve Heat Production Efficiency
Depending on the particular DH boilers, the following renovations should be considered:
- Replacing burners and burning technologies;
- Intensifying furnace heat exchange;
- Converting to gas-fired boilers;
- Introducing technical improvements to increase heat production efficiency.
In addition, а number of organizational measures is crucial for DH efficiency improvement:
- at the local level - better commercial, financial and organizational management;
- at the national level - modifying the traiff system to provide incentives for efficiency improvements at DH enterprises.
GTCC - Gas Turbine Combined Cycle
CHP Combined Heat and Power Plants
Source: International District Heating Association, 2000
Recommended Technical Improvements for Specific Boiler Situations:
- Boilers below one gigacalorie capacity with efficiency below 65% - boiler should be replaced.
- Boilers with efficiency above 65% - reconstructing pads, replacing burners and installing intermediate radiators will yield efficiency levels of from 75% to 92%.
- Boilers below 20 gigacalorie capacity - replacing burners with more efficient ones will result in approximately 95% efficiency, reduce electricity consumption by 14% and reduce nitrous oxide emissions by 55%.
- PTVM and KVGM type boilers replacing burners with two-stage combustion burners will significantly improve performance. Additional useful measures include installation of contact waste gas heaters and heaters for waste gases and heavy oil.
DH distribution networks in Ukraine are typically outdated and poorly insulated. Heat loss during transmission between the point of production and the end-user may range from 8% to 25%, depending on the length of the system. Switching to modern methods of laying and insulating pipe could result in fuel savings of up to 22%, and conformably significant GHG emission reductions.
Methods to Improve Heat Distribution Efficiency
Factors affecting heat distribution efficiency include pipe insulation and network design. For old systems requiring rehabilitation, improvements will generally focus on improving pipe insulation. There have been many advances in insulation technology in recent years, and installation of pre-insulated pipe has become an attractive option in many situations. For newer systems, in addition to pipe insulation, important efficiency considerations include pipeline length, type, and installation method.
Poorly insulated buildings can lose from 30% to 50% of their heat to the environment. It has been estimated that а national program to improve building insulation in Ukraine could save up to 2.4 million metric tons of coal equivalent. (Source: Institute of Industrial Ecology, Kyiv, 1999).
Methods to Improve End-use Efficiency
The main objective is establishing а system that provides incentives for consumers to save energy - the demand side management. There are numerous ways to increase the efficiency at the consumer level, some more cost effective than others, these include:
- Installing of heat meters in buildings and individual apartments
- Installing of heat controls in buildings and individual apartments
- Weatherization of holidays, including windows' replacing
- Installing or replacing pipe insulation
- Installing thermal reflectors on walls behind radiators
- Installing or replacing attic, basement and roof insulation
- Renovating or replacing building exterior doors and staircase windows
- Renovating or replacing doors between apartments and common areas.
Improving DH systems at the production, distribution, and consumption stages can result in significant energy cost savings and reduce greenhouse gas emissions. The inefficiencies and solutions are well understood in Ukraine the challenge is to put the solutions into practice. Obstacles to success must be addressed through public awareness, policy and institutional reforms, and reforming the legal environment. Efforts to improve DH systems have already been undertaken in Ukraine by the private sector and national and local governments, often with the assistance of international donors. For examples of current district heating project efforts, view the Investment Opportunities and Activities Data Base on this website.