Central Heating Plant
Central Heating Plant
Central Heating Plant
What is a Central Heating Plant?
The central heating plant combines one or more heat sources into a complete system. Fossil combustion solutions, commonly referred to as oil and gas boilers, are gradually being replaced or supplemented with alternative solutions. Heat pumps or renewable forms of heat generation, such as thermal solar systems, are on the rise and help to reduce CO2 emissions.
The energy efficiency in a boiler room depends on the careful selection of the heat generator and the use of suitable piping for the hydronic distribution, as well as consumer circuits with high quality valves that control precisely and close 'air bubble tight' when not in operation.
Schematic
Common Issues with Non-Condensing Boilers and Why You Should Choose the Belimo Energy Valve™
Retrofitting an EV in an existing installation will not only ensure that the valve will eliminate hidden water flow circulation in standby periods, it will also create full system transparency (volumetric flow, power, temperatures, and cooling/heating output) with data recording and optional Belimo Cloud connection.
Problem: Poor performance of outdated old boiler designs
Non-condensing boilers are often equipped with a 3-way globe valve to prevent condensation inside the boiler during startup, as this would lead to corrosion and, over time, to failure of the boiler. The 3-way globe valve is often positioned with caution, allowing a small amount of flow back to the return, even after the warm up process is complete.
Solution: Energy Valve retrofit
Retrofitting the EV to an existing non-condensing boiler will help to monitor your existing installation and allow the system to sense when the return water temperature is above the minimum level, and close the bypass valve completely.
Problem: Poor energy efficiency of condensing boiler
Condensing boilers achieve high efficiency (typically greater than 90%) by condensing water vapour in the exhaust gases, recovering its latent heat, which would otherwise have been wasted. This condensed vapour leaves the system in liquid form, via a drain. The return water temperature to the boiler must be below the dew point of the incoming fuel, to permit the condensing process to occur. When coils or radiators are unable to transfer the required amount of energy, the resulting elevated return water temperatures prevent the boiler from condensing, dramatically reducing the efficiency of the boiler.
Solution: Boiler replacement and Energy Valve retrofit
The EV will log temperature and flow, to help determine the correct flow of the pump, ensuring your return water temperature remains below the dew point of the incoming fuel. This minimising pump energy and maximising boiler efficiency. Thanks to the EV, you can now constantly monitor the return temperature from your consumers. You will be able to identify hydronic problems of your existing installations. These are often:
- Open bypass valves flooding your circuit with hot water, not supplying remote consumers
- Valves in closed positions that are leaking/passing, resulting in ghost energy
- Foul coils not able to transfer the required power
- Scale in potable hot water tanks
- Blocked strainers
Heating Valve Applications
Both injection and mixing circuits offer the capability to deliver different temperatures to different circuits, but are complex and require additional equipment. Throttling control valves offer numerous efficiency advantages, but are not able to deliver different flows temperatures to different circuits. The figure below shows the different piping options.
