Capacity Control in Refrigeration Systems
(AR - 021)

1 Freezing stage 2 Evaporator A 3 Flowmeter 4 Heat exchanger 5 Sight Glass 6 Filter 7 Valve 8 Pressure gauge 9 KVL 10 KVC 11 Solenoid valve 12 Liquid receiver 13 Condenser fan and coil 14 Compressor 15 Accumulator 16 Cooling stage 17 Evaporator B

  • Operating chamber 1 without heat exchanger
  • Operating chamber 1 with heat exchanger
  • Operating chamber 2 without heat exchanger
  • Operating chamber 2 with heat exchanger
  • Operating chamber 1 and chamber 2 without heat exchanger
  • Operating chamber 1 and chamber 2 with heat exchangers
  • Observing the effect of Iced-filter or drier on the refrigeration or freezing cycle parameters.
  • Observing the effect of clogged delivery pipe at the compressor on the refrigeration or freezing cycle parameters.
  • Observing the effect of a leaking compressor on the refrigeration or freezing cycle parameters.
  • Observing the effect of clogged intake pipe at the compressor on the refrigeration or freezing cycle parameters.
  • Observing the effect of a faulty KVC capacity controller on the refrigeration or freezing cycle parameters.
  • Observing the effect of a faulty KVP evaporation pressure controller on the refrigeration or freezing cycle parameters.
  • Observing the effect of a faulty KVL Start-up controller on the refrigeration or freezing cycle parameters.
  • Observing the effect of a faulty expansion valve on the freezing cycle parameters.
  • Observing the effect of a faulty expansion valve on the refrigeration cycle parameters.
  • Observing the effect of a faulty evaporator fan on the freezing cycle parameters.
  • Observing the effect of a faulty evaporator fan on the refrigeration cycle parameters.
  • Observing the effect of a faulty condenser fan on the freezing or refrigeration cycle parameters.
  • Compressor
    • Displacement (1450 RPM 50Hz): 7,58 m³/h
    • Max. pressure (LP/HP): 19 / 32 bar
    • Max. Power: 2.7 kW
    • Cooling capacity: 2,16 kW
    • Voltage range 380-420V
  • Refrigerant
    • R-134a.
    • Recharge quantity: 3.2 Kg
    • Accumulator
    • Working Pressure = 33 Bar.
    • Working temperature= -10 +120°C
    • Hstatic / pneumatic =37 /48
    • Inlet/Outlet = ´5/8 - ´5/8
    • Oil separator
    • Working Pressure = 33 Bar.
    • Working temperature= -10 +120°C
    • Hstatic / pneumatic =37 /48
    • Inlet/Outlet = ´5/8 - ´5/8
  • KVR
    • Refrigerants: HCFC, HFC and HC: KVR 12- 22 , HCFC and non-flammable HFC: KVR 28-35
    • Regulation range: Pe = 73.00 – 254.00 psig, Factory setting = 145 psig
    • Maximum working pressure: PS/MWP = 406 psig
    • Maximum test pressure Pe = 450 psig Medium temperature range -49 – 266 °F
    • P band (full valve stroke) 12 – 22: 90 psi, 28 – 35: 72.5 psi.
  • KVL 15
    • Refrigerants: HCFC, HFC and HC
    • Regulating range: 0.2 – 6 bar / Factory setting = 2 bar
    • Maximum working pressure: PS/MWP = 18 bar.
    • Maximum test pressure: Pe = 19.8 bar.
    • Medium temperature range: -60 – 130°C
    • Maximum P-band: 2 bar
    • kv-value 1) with maximum P-band: 3.2 m3/h
    • The kv value is the flow of water in [m3/h] at a pressure drop across valve of 1 bar, ρ = 1000 kg/m3.
  • KVC
    • Refrigerants: HCFC, HFC and HC
    • Regulating range : 0.2 – 6.0 bar /Factory setting = 2 bar
    • Maximum working pressure PS/MWP = 28 bar
    • Maximum test pressure Pe = 31 bar
    • Medium temperature range -45 – 130 °C
    • Maximum P-band 2.0 bar
    • kv value at maximum P-band 1) KVC 12 = 0.68 m3/h KVC 15 = 1.25 m3/h KVC 20 = 1.85 m3/h
    • The kv value is the flow of water in [m3/h] at a pressure drop across valve of 1 bar, ρ = 1000 kg/m3.
  • KVP
    • Refrigerants KVP 12-22: HCFC, HFC and HC / KVP 12-22: HCFC, HFC and HC
    • Regulating range 0 – 5.5 bar Factory setting = 2 bar
    • Maximum working pressure PS/MWP PS = 18 bar
    • Maximum test pressure Pe = PS × 1.1 = 19.8 bar
    • Medium temperature range -45 – 130 °C
    • Maximum P-band KVP 12 – 22: 1.7 bar /KVP 28 – 35: 2.8 bar
    • kv-value 1) with offset 0.6 bar KVP 12 –22: 1.7 m3/h / KVP 28 – 35: 2.8 m3/h
    • kv-value 1) with maximum P-band KVP 12 – 22: 2.5 m3/h KVP 28 – 35: 8.0 m3/h
    • The kv value is the flow of water in [m3/h] at a pressure drop across valve of 1 bar, ρ = 1000 kg/m3.
  • • Absorption Refrigeration System (AR - 021) • Hard Copy User manual • BEDO Software
  • Laboratory PC

The trainer of capacity control and Faults in refrigeration systems tends to demonstrate how the capacity of one compressor can be controlled in order to serve two different loads (freezing and cooling). The trainer is supplied with software to operate the refrigerant systems, control it and activate faults.

                                     
  • The trainer includes all the components of the refrigerant cycle in addition to the freezing and cooling chambers.
  • The components and the two chambers are arranged clearly and sequent in the same way they are arranged in the real-life applications.
  • The refrigerant cycle is divided into two branches, each for one load.
  • The refrigerant cycle components are an accumulator, a compressor, an oil filter, condenser fan and coil, and a liquid receiver.
  • The refrigerant cycle also contains many types of compressor capacity controllers such as evaporator pressure regulator, type KVP, crankcase pressure regulator, type KVL, KVC and Condensing pressure regulator, type KVR, solenoid valves, filters, expansion valves, flow meters, heat exchangers, pressure gauges and sight glass.
  • The solenoid valves enable the separate or parallel operation of the evaporators in the two chambers.
  • The educational unit is provided with two chambers, with door and locker, one of them to simulate the freezing process (one of the two loads) and has its evaporator and the other one to simulate the cooling process (the other load) and has its evaporator too.
  • The two evaporators enable the supercoiling of the refrigerant to be investigated for the efficiency of the process.
  • The refrigeration capacity of the two chambers is controlled by a thermostat.
  • The cooling chamber also features an evaporation pressure controller.
  • There are two defrosting methods for the freezing chamber: an electric defrost heater and a hot gas defrosting where the hot refrigerant is fed directly from the compressor in the opposite direction through the evaporator.
  • The software provided with the trainer operates the refrigerant cycle, controls refrigeration parameters and activates faults.
  • The trainer is supplied with an ON/OFF switch to connect the power supply to the trainer and an emergency switch.
  • A schematic diagram is printed to the trainer to show the sequence of the refrigerant cycle during operation.