with azbil
A to ZLearn with A to Z and everything will be clear! Keywords
- NEW
District heating
A system where various types of heat source equipment produce heat transfer media such as chilled water, hot water, and steam, and this equipment is centrally managed from a heat supply plant. The plant supplies the heat transfer media to buildings within a specific area using local pipelines, providing services such as cooling, heating, and hot water supply. Since there is no need for each building to have its own heat source equipment, the system allows for high-efficiency operation. It also enables the use of renewable energy sources that are difficult to utilize in individual buildings, thus achieving energy savings and reducing environmental impact.
© Hiroyuki Hayashi
Supplying thermal energy to local areas, supporting building air conditioning and hot water supply
In Japan, one of the goals is to promote urban development and create attractive cities through collaboration between the government and the private sector, particularly in major cities, to strengthen international competitiveness. As part of urban development, cities are working to establish systems called district heating. District heating is a system in which heat transfer media (chilled water, hot water, steam, etc.) used for building air conditioning and hot water supply are produced and supplied locally. The produced heat transfer media are supplied to buildings within the area through pipelines. In contrast to a system where heat is supplied by installing boilers and other heat source equipment in each building, manufacturing and supplying heat centrally at a single heat supply plant allows for efficient use of energy and space and offers a variety of benefits such as energy savings and CO2 reduction.
Full-scale district heating in Japan first started in the area surrounding the site of the 1970 World Exposition (Osaka Expo) and has since spread throughout the country. In recent years, district heating has been attracting attention against the backdrop of social issues such as carbon neutrality, the use of renewable energy, BCP (business continuity plan), and DCP (community continuity plan) measures, and it has been introduced in about 130 regions across the country.
Meeting needs such as energy savings, carbon neutrality, BCP/DCP, etc.
One of the benefits of district heating is that it actively uses previously unused energy. Unused energy is a general term for energy that has not been utilized until now despite the possibility of being used effectively, such as waste heat from factories, temperature difference energy from river water and sewage (which is colder than the air in summer and warmer than the air in winter), and waste heat from heating and cooling systems in subways and underground shopping malls. With district heating, energy that would be difficult to utilize in individual buildings can be converted into a heat transfer medium at a heat supply plant and distributed across the entire district.
Moreover, by installing cutting-edge equipment in the heat source facilities and controlling the number of heat source units to operate them efficiently, it is possible to optimize operations such as start/stop based on load prediction. The utilization of waste heat through a cogeneration system1, and effective use of electricity through a large-scale heat storage system, makes significant energy savings possible. District heating also plays an important role in achieving carbon neutrality by 2050.
In addition, district heating provides various benefits to consumers. For example, one advantage is that heat can be used reliably 24 hours a day, 365 days a year, without the need to install and operate heat source equipment in individual buildings such as office buildings or commercial buildings. Since no heat source equipment is required, initial costs, including those from the associated electrical equipment, wiring equipment, and ventilation equipment, can be reduced, and the usable area of the building can be expanded. Furthermore, it is expected to play an important role as infrastructure in the event of a disaster in terms of BCP and DCP measures. For example, the cogeneration system that is used during normal times can be used to supply electricity in emergencies, and the water stored in the heat storage tank can be used effectively for local daily living purposes.
Expectations are high for this infrastructure to support comfortable living through a stable supply of heat
As such, district heating is attracting a great deal of attention as infrastructure that can help meet urban needs for a stable heat supply, save energy, achieve carbon neutrality, and even address social issues such as BCP and DCP. In this context, efforts are currently underway to develop systems that supply not only heat transfer media such as chilled water, hot water, and steam, but also high-voltage electricity through district heat supply. Additionally, there are initiatives to adjust supply based on the energy demand situation of consumers by two-way exchanges of information between heat supply facilities and consumers.
New operational models are also emerging in which the heat supply plants of two adjacent city blocks are linked to each other to interchange energy supplies according to each other’s demand conditions, or to compensate for any breakdowns in the equipment at one of the heat supply plants.
In this way, district heating is truly a unsung hero that quietly supports comfortable living behind the scenes.
- 1 ： Cogeneration
A system that generates electricity using fuels such as natural gas, oil, and LPG, while simultaneously recovering the waste heat generated during the process. The recovered waste heat can be used as steam or hot water for factory heat sources, air conditioning, heating, hot water, etc., achieving high overall energy efficiency.
Related information
