What will we do with our cities? The challenge of energy transition
The world is experiencing an exceptional urbanization process: cities are expanding and are increasingly densely populated. This implies a large consumption of resources, including energy. The heating and cooling sector is one of the most energy-intensive. This energy requirement is largely met by fossil fuels, with serious consequences related to the emissions of greenhouse gases, responsible for global warming.
The adoption of sustainable heating and air conditioning systems in buildings would therefore give a strong push to achieve the objectives of decarbonisation and improvement of air quality.
District heating: what it is and how it works
Image: source Airu
District heating (more rarely called teleheating), is a form of urban heating that uses waste heat recovered on the territory or produced by industrial plants, by a thermoelectric plant or by a cogeneration plant. A large variety of fuels can be used to generate heat, including natural gas, biomass, municipal solid waste.
The recovered heat is used to heat a carrier fluid (hot water, superheated water or steam) which reaches a temperature of 90-120 ° C. Insulated “delivery” pipes distribute the carrier fluid and transport it to individual buildings where takes place the meeting with the heat exchanger. The heat exchanger allows the transfer of the heat taken from the district heating network to the heating systems of the buildings, offering also the possibility of producing domestic hot water.
The temperature probes indicate the amount of heat required by the building to the control unit which operates, proportionally to the request, the regulation valve to increase or decrease the flow of hot or superheated water in the exchanger.
At any time it is possible to change the temperature of the fluid in the hydraulic circuit in the building and adjust the temperature of the rooms to be heated. The heat consumption is calculated and stored by a measurement group which detects the flow rate and the inlet and outlet temperatures of the district heating water. Once the water in the systems is heated, the heat carrier fluid cools and returns to the thermal power plants through the “return” pipes. A specific feature of the district heating service is the distance between the point of production and the points of use of the heat: a plant can serve buildings located even a few kilometers away connected by piping networks.
District heating is an advantageous solution from various points of view:
- It brings environmental benefits: it contributes to the improvement of air quality through the reduction of emissions of polluting substances and greenhouse gases. It also allows a better control, a reduction in the number and a more adequate localization of the emission points.
- It is efficient: it allows greater energy savings, lower consumption of fossil primary energy thanks to the use of renewable energy sources, biomass, waste thermal destruction, solar,geothermal energy. It allows to recover otherwise dispersed heat generated by existing industrial processes. Combined with a cogeneration plant, it offers higher average yields with the same fuel used.
- It combines thermal comfort and preservation of buildings aesthetics: it is particularly suitable where other energy efficiency interventions are difficult to do, such as the replacement of windows, the installation of external coats or the insulation of roofs.
It offers to the end user savings in maintenance, in fact there is no risk of dross accumulation due to the transport of fuel.
- It is an immediately applicable solution that has very important development prospects both for cities and for induced employment and therefore for the Gross Domestic Product.
The global situation
District heating has been introduced more than fifty years ago and today it is used mainly in North America, Europe, Japan, Korea and China. Combined Heat and Power (CHP) market predominantly accounts for the majority market share across the global district heating industry. The global District Heating market size is expected to grow ( with a CAGR of 2.7% ) in the forecast period 2020 – 2025, and will expected to reach USD 169.340 million by 2025, from USD 152.150 million in 2019.
“Measuring” efficiency: the necessary tools
As we have seen, district heating can play an important role in the future energy challenges: the sector is among those that can contribute most to the achievement of the global energy efficiency and decarbonization objectives.
It is therefore necessary to promote their diffusion, more investments are needed, a framework of reliable and stable rules and quality technological solutions, capable of providing highly precise and reliable measurements.
The service life of district heating networks should not be less than thirty years: in order to meet this requirement, correct network design is needed but also a monitoring of their conditions to promptly detect any faults and plan adequate maintenance activities.
Equally important are the technologies for heat metering: this can be considered the economic heart of all district heating systems.
It is important to have measuring tools capable of providing reliable data on actual energy consumption.
ISOIL Industria is active in the development and production of measurement technologies, offering cutting-edge, certified solutions (MI-001, MI-004, OIML R49, SIL, PED, Atex and more) organized into specific product lines: ISOMAG (electromagnetic flow meters), ISOFLUX (ultrasonic meters and heat meters), ISONRG (electrical and thermal energy meters) and ISOD@M (data acquisition and management software).
“We can provide everything that includes the measurement of thermal energy, from the production phase to final consumption, with the specific breakdown by individual user” explains Luigi Solofrizzo, Director of Isothermic, the ISOIL Industria Division specifically focused on the thermal sector.
For information, do not hesitate to contact the company: our technicians will provide you with valuable support and useful advice to meet your needs.