Learning chapter

Refrigeration Plant

12 lessons

The whole refrigeration plant from cycle to overhaul: refrigerants, compressor, condenser and evaporator, expansion valves, controls and safeties, oil management, watchkeeping, troubleshooting, air conditioning and safety.

This chapter collects 12 illustrated lessons on Refrigeration Plant as part of Auxiliary Machinery & Shipboard Systems, ordered as they are best studied. It opens with Refrigeration Principles and the Vapour Compression Cycle, Refrigerants, The Refrigeration Compressor, Condensers, Evaporators and Heat Transfer, Expansion Valves and Liquid Level Control, Controls, Safety Devices and Circuit Components and 6 more. Each lesson is written for MEO oral and written preparation: definitions first, then how the system behaves, then the checks and figures used in practice.

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01 Refrigeration Principles and the Vapour Compression CycleThe vapour compression cycle explained: latent heat, saturation temperature, the four components, COP, reading the p-h chart, and multistage cycles.10 sections 02 RefrigerantsRefrigerants from R12 and R22 to R134a, CO2 and ammonia: properties, pressure tables, ODP and GWP, TEWI, charging procedure and leak detection.7 sections 03 The Refrigeration CompressorRefrigeration compressors: reciprocating construction and valves, capacity reduction by unloading, cooling, lubrication, shaft glands and hermetic drives, plus rotary, screw, scroll and centrifugal types.9 sections 04 Condensers, Evaporators and Heat TransferRefrigeration condensers and evaporators: shell-and-tube construction, air-cooled and water-cooled types, evaporator flow patterns, LMTD, the dirty-filter power penalty and defrosting.6 sections 05 Expansion Valves and Liquid Level ControlExpansion valves for marine refrigeration: float valves, the thermostatic expansion valve force balance and superheat, equalising connections, hunting, electronic valves and fault diagnosis.9 sections 06 Controls, Safety Devices and Circuit ComponentsRefrigeration controls and safeties: HP and LP cut-outs, pump-down circuit, oil differential cut-out, solenoids, back pressure valves, strainer-driers, sight glasses and relief valves.10 sections 07 Oil in Refrigerant SystemsOil in marine refrigeration systems: oil specification, pour point against floc point, miscibility and oil return velocity, oil separators, oil traps and rectifiers, and shipboard oil procedures.11 sections 08 System Operation, Watchkeeping and Shipboard ProceduresOperating a marine refrigeration plant: the two cardinal running rules, the running log and its columns, brine cargo systems, safe isolation sequence, purging air, charging, compressor valve tests and defrosting routine.14 sections 09 Troubleshooting and Fault-FindingRefrigeration fault-finding: undercharge, overcharge, moisture, air, oil carry-over, flooding, valve defects, short cycling and a rising discharge pressure — symptom to remedy.5 sections 10 Air ConditioningMarine air conditioning: psychrometry, dew point, relative humidity and the psychrometric chart; comfort conditions, over-cool and reheat, single and twin duct systems, and Legionella control.8 sections 11 Maintenance, Overhaul, Inspection and RepairMarine refrigeration maintenance: user routine, planned compressor overhaul, strip-down inspection, leak testing and repair, heat exchanger cleaning, annual safety control testing and spares.10 sections 12 Safety and EmergenciesRefrigeration safety at sea: asphyxiation, phosgene from halocarbon in flame, frostbite, ammonia, relief valves and bursting discs, safe isolation, suspect oil and emergency response.12 sections