The refrigeration pack is the centrepiece of a refrigeration system, and the pack controller, the “brain”, which approximates the real cycle to the thermodynamic ideal through intelligent control strategies, thus ensuring the energy-efficient and safe operation of refrigeration systems.
Pack controllers for refrigeration systems
For the control and monitoring of refrigeration systems, the E*LDS system provides different pack controllers: the basic model VS 3010 and the compact low-cost version VS 300 for use in standard refrigeration racks, the VS 3010 BS type for booster satellite systems and the FS 3010 model for brine and water chillers.
Modern transcritical refrigeration systems with CO2 (R744) as refrigerant can be optimally controlled with the VS 3010 CT. Eckelmann also provides suitable solution for cascade systems, e.g. with R744 and R134a as refrigerants. E * LDS supports all common, natural and synthetic refrigerants.
The pack controller is used in compressor pack controllers with normal and low temperature refrigeration. By using SIOX expansion modules, up to 12 compressor stages and condenser fan stages can be operated with a pack controller.
Controlling with modern technologies saves energy and operating costs. Load shedding management and suction pressure optimisation are functions included in the standard version. There are numerous configuration options and settings to simplify operation and maintenance tasks.
The pack controller is operated via the system centre or an additional operator terminal. Laptops or PCs with LDSWin software can also be used for convenient parameterisation and optimisation.
Increased energy efficiency through optimal control of compressor capacity
The energy efficiency of a refrigeration system can be measured by the difference between evaporating and condensing temperature. For the quotient of condenser and refrigeration capacity (the COP value) to be as high as possible, the temperature difference ought to be as small as possible.
Next to the evaporating temperature, the condenser temperature is therefore the second significant correcting variable. By, amongst other things, intelligently controlling the drive speed, modern pack controllers adjust the condenser capacity to the current refrigerant requirement of the refrigeration points. Lowering condenser temperature by 1 Kelvin leads to energy savings of up to 3 percent.
Enthalpy control and a setpoint shift of evaporator (p0) and condensation pressure (pc) increase energy efficiency and ensure optimal refrigerant sub-cooling; thermodynamic losses due to the formation of flash gas in the refrigerant pipes are minimised.
In systems with combined heat recovery, the pack controllers from Eckelmann can also be used for the control of this interface with the refrigeration cycle.
- Adaptive and weather-dependent control of suction pressure
- Enthalpy control
- Load shedding management for lower current supply costs
- Condensing pressure control via step, speed and combined control