23 September 2009
Delta T is the temperature difference between the water entering and the water leaving, e.g. a cooling unit. Dynamic valves ensure that pressure fluctuations in the system do not affect water flow, which would otherwise lead to poor cooling.
It is important to note that a system with dynamic valves is already balanced. When the dimensioned flow is pre-set on the valves, all that has to be done is start the pump and make sure that this operates with the lowest consumption of energy. This is achieved by ensuring the critical valve has sufficient pump pressure available. The critical valve is typically the valve that is furthest from the pump. The valves automatically find the hydraulic balance regardless of pressure fluctuations in the system. This leads to better comfort, greater flexibility and environmental energy optimisation. System expansion at a later date does not require re-commissioning the original system. The hydraulic balance will be maintained, and the pump will simply need to be configured to the new conditions.
The Frese development department has been working with a large international partner in recent years on the expansion of the PIV product range - Pressure Independent Control Valves. Frese has named the new valves OPTIMA.
OPTIMA is an intelligent control valve. A three-in-one valve; it maintains balance in the system, controls room temperature and ensures pressure fluctuations do not affect either balance or room temperature. Naturally, project engineers find the valve easy to work with, as the valve authority is always one. This means that differential pressure will not affect the OPTIMA - no matter if it is positioned close to the pump where differential pressure is always greater than if it was placed further away, where differential pressure is lower. In addition, full modulating control is always achieved with OPTIMA, which means the actuator's full stroke is utilised no matter what value of flow the valve is pre-set to. OPTIMA has been on the market for over three years and has been positively received everywhere.
From autumn 2009, the OPTIMA range of valves will include sizes ½" to 2". In addition, we are working with our partner to further widen the product range with a series of flange valves, initially up to DN80.
Looking further ahead, I am convinced we will see actuators, valves and BMS systems becoming increasingly integrated. BMS stands for Building Management System. Basically, it is computer-controlled monitoring and management of, for example, cooling and heating systems in larger buildings.
To save as much energy as possible, only the precise amount of energy required is used at any given time in any 24-hour period. This is where the increasing integration of valves, actuators and the BMS system will pay dividends.
We at Frese can see that not everyone has taken the dynamic solutions to heart yet. But we are convinced it is only a matter of time. Dynamic valves in cooling and heating systems make life easier for project engineers, pipe fitters, and the operating department. They also save a great deal of money and improve the environment.
By Ole Jørgensen, Head of Development, Frese A/S
