Capacity control in refrigeration systems Investigation of different capacity control methods Features - investigation of different capacity control methods - open compressor with variable speed - adjustable cooling load via heater - controlled defrosting with temperature specification Learning objectives/experiments - key devices for changing the refrigeration capacity -- thermostat -- evaporation pressure controller -- refrigeration controller -- capacity controller -- compressor with variable speed - operation of a refrigeration controller with specification of temperatures for -- controlling the refrigeration capacity -- switching the defrost heater on and off -- switching the ventilators on and off Specification [1] methods for capacity control in refrigeration systems [2] refrigeration circuit with compressor, condenser and evaporators in insulated refrigeration chambers [3] each refrigeration chamber with adjustable heater to generate a cooling load, thermostatic expansion valve and 2 ventilators [4] 1 refrigeration chamber with refrigeration controller for temperature control; solenoid valve, ventilators and defrost heater as actuators [5] 1 refrigeration chamber with thermostat, solenoid valve and evaporation pressure controller for temperature control [6] compressor with variable speed via frequency converter [7] capacity controller in the compressor bypass [8] refrigerant R513A, GWP: 631 Technical data Compressor - refrigeration capacity: approx. 560W at -5/25°C and 1450min-1 - drive motor: 550W 2 heaters: approx. 500W 4 ventilators: max. volumetric air flow rate: approx. 36,5m3/h 1 defrost heater: approx. 75W Refrigeration controller - 3 inputs - 3 outputs Evaporation pressure controller: 0...5,5bar Thermostat: -5...20°C Capacity controller: 0,2...6bar Refrigerant - R513A - GWP: 631 - filling volume: 1kg - CO2-equivalent: 0,6t Measuring ranges - speed: compressor 465...975min-1 - temperature: 3x -60...50°C - power: heater 2x 0...1000W - pressure: 3x -1...9bar; 1x -1...24bar 230V, 50Hz, 1 phase 230V, 60Hz, 1 phase; 230V, 60Hz, 3 phases UL/CSA optional LxWxH: 1100x750x1900mm Weight: approx. 150kg