Special Cooling Systems
LNX Special Cooling System
The cooling systems of series LNX have been developed for the cooling of machines and systems which require various temperatures, e.g. vacuum installations where a lower temperature is required for the vacuum pumps than for the furnace circuit. Usual temperatures in the cooling circuit are approx. 12-15 °C.
Structure and Function
Working on the basis of heat exchangers, the temperature of the circulating water flowing to the consumer cannot be lower than the temperature of the cooling water available. This means that external water is required. The cooling capacity of the systems depends mainly on the temperature difference between circulating water and cooling water.
Depending on the operating point, the cooling capacities can be between 80 and 500 kW. By selecting the respective pumps, the desired water quantity and the required pressure can be provided. The systems are delivered in a turnkey manner: Completely assembled, internally piped and factory-tested. They require very litte space.
The system consists of the following elements:
3. Heat exchanger
4. (Emergency water supply)
5. Fittings like stopcocks, non-return flaps etc.
6. Respective sensor system
7. Entire control system via PLC
8. Temperature control via proportional valve (with external water)
If a dry cooler is used: Pump station for the glycol circuit with all fittings required like expansion tank, feeding valve etc.
9. Dry cooler
The consumer pump(s) suck(s) water from the tank and convey(s) it to the consumer.
With pressure-controlled pumps, a constant pressure is maintained through the speed independent of the actual consumption. The return flow from the consumer is passed through the heat exchanger where it is cooled down again. Cooling is effected via external cooling water whereas the temperature is controlled through a proportional valve.
If cooling is effected via the dry cooler, the pump for the dry cooler circuit is switched on when the preset temperature of the tank is exceeded and the liquid is conveyed through the dry cooler. The temperature of this circuit is controlled by the speed of the fans.
This means that the speed of the fans is reduced when the ambient temperature is low which contributes to the saving of energy.
The system is normally controlled using a Siemens PLC. Depending on the design, the system can be operated via an alphanumeric display or via touchscreen. Hence a data logger function which can record and save all relevant data like pressures, flows, temperatures and switching states etc. can be used.
This function offers substantial advantages with regard to monitoring, service and troubleshooting. Of course, data can also be transferred to other users.