новости компании о Twin-Screw Refrigeration Compressor: How 5:6 Rotor Profiles Boost Volumetric Efficiency

In heavy-duty industrial refrigeration and large-scale cold storage facilities, the twin-screw refrigeration compressor serves as the heart of the thermal exchange cycle. To maximize system COP (Coefficient of Performance), optimization of the compressor’s volumetric efficiency is critical. This metric—representing the ratio of actual intake volume to theoretical displacement—is fundamentally determined by rotor profile geometry and machining tolerances.

Modern industrial screw compressors increasingly utilize a 5:6 asymmetric rotor profile, featuring 5 lobes on the male rotor and 6 flutes on the female rotor. Compared to traditional symmetric configurations, this asymmetrical geometry significantly minimizes the "blow-by" leakage path (the leakage triangle) between the high-pressure and low-pressure chambers during the compression cycle.

This reduction in internal gas bypass directly increases the volumetric output per revolution. As a result, the system maintains stable volumetric efficiency even under demanding evaporating temperatures ranging from -45°C to -10°C.

Achieving these efficiency gains requires strict manufacturing standards and high-grade materials. To prevent rotor deflection under high torque and extreme pressure differentials, premium rotors are machined from high-tensile 42CrMo forged steel.

• Precision Tolerances: Advanced CNC profile grinding machines ensure tooth-profile tolerances are held within ±0.005 mm.
• Surface Finish: Surface roughness ($R_a$) is controlled to less than 0.4 microns.
• Dynamic Clearances: These precise tolerances allow the design clearances between the meshing rotors to be maintained at a uniform range of 0.03 mm to 0.05 mm, ensuring a stable dynamic oil-film seal without metal-to-metal contact.

From the perspective of preventive compressor maintenance, the 5:6 asymmetrical profile distributes mechanical loads more evenly along the rotor contact lines. This even distribution reduces localized shear stress on the lubricating oil and minimizes wear on the bearing assembly.

Equipped with heavy-duty roller bearings rated for an $L_{10}$ bearing life of over 50,000 hours, these units exhibit minimal vibration. Vibration levels are typically kept below 2.8 mm/s in accordance with ISO 10816 standards, drastically extending the service intervals of the entire system.