Xinwuxin parallel screw packages · Compressor and oil-system scope

Resolve the mechanical identity before specifying duty

The body attributes long bearing life and inspection intervals to an open single-screw compressor. The original tables instead state semi-hermetic twin-screw compression with liquid-injection cooling and star-delta starting. These constructions cannot be merged into one authoritative equipment specification. The family illustration cannot identify the actual internal screw arrangement or verify the compressor make.

Require the selected compressor manufacturer/model, open versus semi-hermetic arrangement, screw configuration and stage scheme. Ask the supplier to issue the correct catalogue revision and rack bill of materials. Do not apply the narrative’s 100,000-hour bearing-design or 25,000-hour inspection claims to a table model without supporting OEM evidence; neither claim is an independently demonstrated service life.

Keep evaporation temperature separate from the process load

In the first original schedule, model 160.2 at −10°C evaporation gives 194 kW nominal refrigeration and 58 kW compressor input; at −20°C it gives 134 kW and 52 kW. These are evaporation points, not entering/leaving-water temperatures or a confirmed storage-room temperature. The reviewed table does not supply the condensing point and complete fluid/refrigerant test conditions needed for a final selection.

The prose’s single- and two-stage ranges extend beyond the table’s −5/−10/−15/−20°C rows. Ask for an actual performance map at the ordered refrigerant, suction/condensing conditions and required load. Specify how the selected evaporator and condenser affect that operating point. No universal capacity or COP is inferred from an HP range or extrapolated to −65°C.

Close oil management and compressor coordination

The body describes a horizontal three-stage oil separator and states that some units use dual oil filters and a pre-lubrication pump. It also states a 5 ppm oil-separation figure without a reviewed measurement method or duty boundary. Request the exact separator, reservoir, filter, level/pressure monitoring and oil-return arrangement for the selected rack.

Agree how compressor loading, starts, oil balancing and fault isolation work across the package. The tables allow staged or continuous loading, but do not establish a complete rack sequencing algorithm. Determine the available duty with one assembly isolated, minimum stable operation and the required service procedures. Multiple compressors do not by themselves prove full-load standby capacity or uninterrupted operation.

Treat the rack as part of a refrigeration system

The supplier expressly allows different evaporators, condensers and selected protection/explosion-resistance motor requirements. No reviewed current motor certificate or complete hazardous-area package approval supports an explosion-proof claim on this page. Define the actual intended site and require current selected-equipment evidence when applicable.

Request the refrigeration P&ID, pressure boundaries, safety-component schedule and responsibility for field piping, charging and commissioning. The original table’s compressor-input kW does not establish total system input including remote condensers, pumps and fans. A rack quotation should name those excluded/included loads and interfaces instead of appearing comparable solely because two nominal cooling numbers match.

Specify controls and comparable acceptance

The narrative describes a Chinese touchscreen interface, data records, settings, alarms, remote communications and Modbus monitoring. Obtain the real controller revision, protocol/register details, selected language support and permitted remote commands. The listing of a remote interface does not establish safe autonomous recovery from every system fault.

Require a corrected selection map, confirmed compressor construction, oil-system drawings and integrated protective/control tests. Agree performance verification at the same refrigerant and simultaneous suction/condensing conditions, with all quoted auxiliary loads identified. The website’s 30% efficiency improvement lacks a reviewed comparison baseline; price, delivery and independently measured results remain unknown.

1. Confirm compressor and stage scheme

   Resolve conflicting construction descriptions with the actual OEM model and current rack BOM.

2. Select the complete operating point

   Issue refrigerant, suction/condensing duty and the evaporator/condenser package boundary.

3. Approve oil, controls and test scope

   Document coordination, isolation, protective functions and measured acceptance with total included input.