Energy efficiency in refrigeration systems Refrigeration system with three compressors in interconnected operation; adaptation to the capacity requirement Features - refrigeration system with three compressors in interconnected operation - ideal adaptation to the capacity requirement by adding and removing individual compressors - industrial multicompressor controller to add and remove the individual compressors - add-on heat exchanger for refrigerant supercooling - monitoring of the lubrication oil transport in the refrigeration circuit Learning objectives/experiments - variables affecting energy efficiency -- controller parameters -- refrigerant supercooling - interconnected operation of compressors - operation of a multicompressor controller - methods for returning oil in a multicompressor refrigeration system - representation of the thermodynamic cycle in the log p-h diagram Specification [1] refrigeration system in multicompressor operation to investigate energy efficiency [2] refrigeration circuit with 3 compressors connected in parallel, condenser, thermostatic expansion valve and coaxial coil heat exchanger as evaporator [3] heat exchanger for refrigerant supercooling can be added via valves [4] glycol-water circuit includes pump and tank with heater serving as cooling load at the evaporator [5] multicompressor controller for the parallel operation of the compressors [6] separation of oil from the refrigerant on the delivery side and return to the intake side of the compressors [7] fan at the condenser with adjustable speed [8] GUNT software for data acquisition via USB under Windows 10 [9] refrigerant R513A, GWP: 631 Technical data 3 compressors - refrigeration capacity: each 1584W at -10°C/55°C - power consumption: each 1156W at -10°C/55°C Condenser with fan - volumetric air flow rate: 1250m3/h Glycol-water mixture pump - max. flow rate: 4,2m3/h - max. head: 5,6m Heater power: 3kW Tank - glycol-water mixture: 23L - refrigeration circuit receiver: 5,8L Refrigerant: R513A, GWP: 631 - filling volume: 4,2kg - CO2-equivalent: 2,7t Measuring ranges - temperature: 4x 0...100°C, 4x -100°C...100°C - pressure: -1...9bar, -1...24bar - flow rate: 1...25L/min (water) - power: 0...4995W (compressor) 400V, 50Hz, 3 phases 400V, 60Hz, 3 phases; 230V, 60Hz, 3 phases UL/CSA optional LxWxH: 1810x710x1920mm Weight: approx. 265kg