Product Use And Maintenance; Principle Of Work; Ultra-Low Temperature Cabinet Use - Haier DW-86L288 Service Manual

The design of overlaying‐type freezing medium system is used for freezing mediums with
different boiling points; this system needs two independent cooling systems. It is shown as above,
each system can work synchronously; first level system is used for the high temperature section
of second level cooling. Second level is the main system, which is used to maintain the
temperature in low temperature cabinet. Freezing medium is compressed by first level
compressor and condensed by condenser, and then dried by dryer. After passing through
capillary tube, dried freezing medium becomes evaporated gas (low temperature and low
pressure). Heat exchanger is cooled to below ‐20 , which is used for carrying out condensation
on second level system gas. Filter eliminates impurities in freezing medium, freezing medium
goes through liquid separator, which can prevent liquid freezing medium from being absorbed
into compressor. This is an integrated high temperature system refrigerating cycle.
After freezing medium is compressed by second level compressor, freezing medium firstly
receives pre‐cooling of precooler; After passing through oil separator and dryer, it condensates
on heat exchange coil. Condensed freezing medium passes through filter and capillary tube,
then forms low temperature and low pressure liquid and evaporates in evaporator, in this way,
refrigerator body temperature is cooled to ‐86 to ‐90 .
To put it simply: first level compressor operates —— first level heat exchange coil cools——
second level compressor operates ——second level refrigerating system condenses in first level
heat exchanger coil —— second level system reduces the temperature of refrigerator body(lower
than ‐86 or ‐90)
How to use:
After the first use of ultra‐low temperature cabinets, or ultra‐low temperature cabinet by
handling or ultra‐low temperature cabinet power (including power failure) more than 10

Product use and maintenance

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