· Heat Accumulator For District Heating

Heating accumulator

Heating accumulator is a large tank container which could be used as short-term heating storage. Water’s quality in tank is maintained constant, while the energy stored is changing. Heating charging means that the hot water flowed into the tank ceiling and the same quality of cold return water pumped out from the bottom of the tank. Accordingly, heating discharging means that the hot flowed water pumped out from the tank ceiling and the cold return water poured into the bottom of the tank. Because of the different density of different water temperature, hot water and cold water are separated in tank with a transition water layer of 1-2 meters high between them.

If the heating load would be large and changing frequently, accumulator can absorbed excess heat storage in lower heating load term and discharge when the heating load increased. Heating accumulator could ensure heating and power plants in a smooth and economic running mode with highly efficiency

Heating accumulator had be widely used in the heating and power plants in the Nordic region as a flexible heating adjustment measures

Key functions:

1 Optimizing the heating plants and heating system by the charge and discharge function of heat accumulator.
2 As the heating supply buffer between the heat sources and the users.
3 As the peak heat source.
4 As an alternate backup heat source.
5 As the emergency backup supplying water source.
6 Maintaining the pressure level in heating system.

 Key advantages:
1 Meeting the peak load heating system and reducing the amount of original heating system investment.
2 Accumulator could optimize and ensure the smooth power plant operation by reducing the need for substantial heating load changes.
3  Improving the heating system security by the spare heating capacity.
4  Accumulator could supply the heating water and prevent system failures in network when a mass leak happened.

Construction sketch:

Brief of heating accumulator in Beijing Zuojiazhuang heating plant:
·  First district heating accumulator in China.
·   8000m3 accumulator (gross heat storage capacity).
·   Hot water storage temperature 70-98℃.
·   Heat storage capacity of 628 GJ (98/65℃).
·   Operational cycle: Charging 8 hours, discharging 4 hours(adjustable based on different heating condition).
·   Size: Diameter of 23 meters, total height of 23.5 meters.
·  Project was put into operation in December of 2005.