The basic idea of ejector technology is the recycling of existing or, occasionally, purpose-generated differential pressure in water distribution systems. The differential pressure for overcoming system resistance is built up using network pressure at the inlet of the ejector.
Using ejectors in conventional control systems with a 3-way valve and a circulation pump, the heating supply temperature is kept constant or regulated according to the outside temperature. Ejectors are part of the control loop. The practical interaction of the control loop elements enables an optimal system technology with minimal energy consumption.
No electrical circulation pumps are necessary in the consumer circuits
Ejectors are especially durable, simple and low-maintenance control valves. Thus, in consumer circuits, no electric circulating pumps (including the necessary additional controls, data points for superordinate HVAC-systems and check valves) are required. Differential pressure controllers are also avoided. The hydraulics of the entire system are simplified.
In addition, the quantity of water supplied to the consumer (static heating, ventilation register, heat exchanger, etc.) is adapted to suit thermal demand.
More than 40 years of experience
For over 40 years, we have successfully been installing controlled water ejectors in building connection stations and for ventilation registers and heat distributors for water heating.
Most heat exchangers (tube bundle or plate heat exchangers) are still controlled using a globe valve as a throttle. This globe valve is used to control the flow (energy) dependent on the output demand of the consumers connected to the heat exchanger.
With this circuit, the primary supply temperature is always identical to the temperature that enters the heat exchanger. This inlet temperature does not depend on the load, but rather is specified by the company operating the primary network. This means that in partial load operation there is an unnecessarily high inlet temperature on the primary side of the heat exchanger.
This results in a large temperature difference between the inlets on the primary and on the secondary side. This temperature difference generates thermal stresses in the heat exchanger. Stresses are a frequent cause of damage, especially in plate heat exchangers. Furthermore, a large temperature difference results in a lower water volume. In turn, this results in poor heat transfer due to the transition to laminar flow. This causes complicated conditions for the control.
The use of an ejector instead of a control valve enables admixture at almost no extra cost.
Advantages at a glance
- Up to 30-40% lower investment and service costs
- High cost-effectiveness and energy efficiency
- Savings in operating costs
- Hydraulic stability in the energy output circuit
- Improved system availability