A district heating grid is typically designed for the customers with the highest requirements of temperatures and pressures, causing a large number of disadvantages in other parts of the grid.
With Grundfos iGRID Temperature Zone, you can divide the city into smaller zones where demands are lower and thereby reduce heat losses significantly, lower the carbon footprint and increase the grid capacity.
Demand-driven temperature optimisation
The iGRID Temperature Zone is an intelligent mixing loop, ideally connected to Grundfos iGRID Measure Points for demand driven temperature optimisation based on real-time data from strategic points in the grid.
Additionally, it can be installed with the iGRID Temperature Optimiser for optimal temperature control based on peak shaving algorithms, weather compensation and real-time data from iGRID Pit Measure Points.
Reducing temperatures results in significantly reduced heat losses, leading to lower carbon emissions, increased capacity in the grid and an increase of asset lifetime of e.g. pipes and consumer installations.
With these zones, you can even increase pressure where needed to reduce residual pressure in the grid.
Short return on investment
In most heating grids, several parameters lead you to operate differently than originally designed:
• The design is based on the customers requiring the highest temperature and pressure.
Installations are typically at least 20 % oversized
• Energy renovation has been carried out – e.g. new windows, more insulation etc.
• The design peak loads are only reached a few minutes per year
• New and renovated buildings have much lower heat demands
This makes it possible to identify many smaller city zones where temperatures can be significantly reduced, leading to the short returns on investment.
The basic variants of the iGRID Temperature Zone
The iGRID Temperature Zone comes in three fundamental variants of mixing loops to meet different needs. All solutions ensure that the colder return water from the zone is mixed with the hot water from the supply line to reach the needed temperature in the zone – nothing more and nothing less.
The free solution
An efficient solution whereby pressure can be increased in the zone. By the use of a pump in the bypass, the pressure from the supply is adjusted in order to add the required return of water. Consequently, a free flow of water is created and a traditional motor valve is no longer necessary. Nonetheless, the need for maintenance is reduced due to a high degree of reliability.
This is the ideal solution for reducing heat losses to a minimum.
The shunt solution
A cost-effective solution utilising pressure from the main pumps in the existing grid. A pump in the bypass is designed to overcome pressure from the supply to add the needed flow of return water.
This solution is suggested if there is always enough supply pressure for the zone and no ambition to implement the low pressure benefits of distributed pumping.
The pressure reduction solution
A shunt solution with a pressure control valve utilised when the pressure in the zone is higher than required.
This will reduce the pumping need for mixing and pressure reduction in all buildings will no longer be required. Additionally, it will increase the lifetime of pipes and building installations.