Compressor Volumetric Displacement
Compute the volumetric displacement of a reciprocating compressor, Vd = (π/4)·D²·L·n, the volume swept by the pistons, from the cylinder bore (D), the stroke (L) and the number of cylinders (n). It is the compressor's 'displacement' — the theoretical volume aspirated per revolution, which, multiplied by the speed and the volumetric efficiency, gives the actual flow. It defines the compressor capacity. Enter the bore, the stroke and the number of cylinders.
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Deslocamento volumétrico do compressor
O deslocamento volumétrico (a 'cilindrada' do compressor) é o volume que os pistões varrem por revolução: Vd = (π/4)·D²·L·n, função do diâmetro do cilindro (D), do curso do pistão (L) e do número de cilindros (n). É o volume teórico aspirado a cada volta do eixo — e, multiplicado pela rotação (rpm) e pela eficiência volumétrica, dá a vazão volumétrica real de gás que o compressor bombeia. Essa vazão real, dividida pelo volume específico do refrigerante na sucção, dá a vazão mássica, e daí a capacidade frigorífica do sistema. O deslocamento é, portanto, o parâmetro geométrico fundamental que dimensiona um compressor: trocar por um de maior cilindrada (ou aumentar a rotação, em compressores de velocidade variável) aumenta a capacidade. Em compressores scroll, parafuso ou centrífugos a geometria é diferente, mas o conceito de volume deslocado por unidade de tempo permanece central. O π/4·D² é simplesmente a área do pistão; vezes o curso, o volume de um cilindro; vezes o número de cilindros, o total. Informe o diâmetro, o curso e o número de cilindros.
Related Tools
Compressor Volumetric Efficiency
Compute a compressor's volumetric efficiency, ηv = (actual suction flow / volumetric displacement)·100%, the fraction of the piston-swept volume that actually pumps gas. Losses come from clearance volume (gas that re-expands), suction reheating and leakage. It drops as the compression ratio rises. It is a key indicator of compressor performance. Enter the actual suction flow and the volumetric displacement.
Refrigerant Mass Flow
Compute the refrigerant mass flow needed in a cycle, ṁ = refrigerating capacity / refrigerating effect, dividing the desired cooling load (kW) by the specific refrigerating effect (kJ/kg, the enthalpy absorbed per kilo at the evaporator). It is how much refrigerant must circulate per second to meet the demand — the basis for sizing the compressor, the piping and the system gas charge. Enter the refrigerating capacity and the refrigerating effect.
Cold Room Heat Load
Compute the product cooling heat load in a cold room, Q = m·cp·ΔT, from the product mass, its specific heat and the desired temperature change. It is the sensible-heat portion to remove to lower the product temperature — one of the components of the room's total load (which also includes wall transmission, infiltration, lighting, motors and people). It defines the refrigerating capacity needed. Enter the mass, the specific heat and the ΔT.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.