Saturday, February 4, 2017

MDV "DIGITAL SCROLL" SYSTEM

WHAT IS A "DIGITAL SCROLL" SYSTEM

A "Digital Scroll" system is a multi-system with a "digital scroll"  Copeland compressor which can regulate effect, simplifies air-conditioning systems, saves more energy  and gurantees reliable functioning.  Multiple internal units can be attached to one external unit. 

WORKING PRINCIPLE OF A «DIGITAL SCROLL» COMPRESSOR



Compressor characteristics:
  • -    capacity regulation between 10-100% of nominal effect
  • -    large power efficiency dut to constant capacity modulation
  • -    duration of a PMV valve: 30 years
  • -    high efficiency and stability of compressed refrigerant through changing the geometry of volume inside the compressor

VENTIL CLOSED - COMPRESSION



VALVE OPEN – IDLE TIME



A digital scroll compressor modulates power by moving the rotor from the stator through closing/opening the PMV electromagnetic valve.
When the valve is closed, the rotor connects with the stator, pressures equalize, the compression space hermetically closes and the refrigerant is compressed.
When the  valve is open, a difference in pressures occurs so the  stator rises in relation to the rotor by 1 mm. Rotating continues, but the refrigerant does not get compressed.

PRINCIPLE OF REGULATING VARIABLE CAPACITY




A compressor can constantly change the compression period (PMV valve closed) and idle time (PMV valve open) and in that way regulate the quantity of the refrigerant on the compressive side.
By opening and closing the PMV valve power changes continuously.

MAXIMUM SYSTEM POWER EFFICIENCY DUE TO CONSTANT CAPACITY MODULATION


The exchange between compression and idle time cycles enables quick and precise control of refrigerant volume depending on temperature demands in the area.
Capacity regulation area starts from  10 to 100% of nominal capacity. During the compression, energy consumption is 100%, whereas in idle time it is only 10%.
Digital scroll technology guarantees great efficiency with partial load of internal units, and constant exchange between compression and idle time cycles ensures high efficiency and considerable savings in energy.
The advantage of this technology over constant speed and inverter technologies are significant savings and great effectiveness when dealing with small demands for power for achieving set temperature values in spaces.

TOTAL ABSENCE OF ELECTROMAGNETIC INTERFERENCE


Midea digital scroll system does not cause any electromagnetic interference because compression and idle time cycles are regulated electromechanically.
This characteristic presents a great advantage for usage in medical services, telecommunications, electric  central stations and  all other areas where avoiding electromagnetic interferences is important. 

SIMPLICITY OF INSTALLATION AND MAINTENANCE

MDV digital scroll system is a direct expansion system. In comparison with traditional central air-conditioning systems, it does not require a complicated installation process and is much easier to maintain.
The advantages of this system are:
  • -    lower installation and maintenance costs
  • -    the appliance recognizes irregularities on its own so there is no need for a specially trained individual for system maintenance 
  • -    requires less space for installation 
  • -    takes up less space for a pipe line

LENGTH AND HEIGHT DIFFERENCE OF THE PIPE LINE


The technology of this system allows placing of long tracks of pipe lines as well as height differences between units.
  • -    Maximum total length of installations for external units is 150m
  • -    Maximum height difference between external and internal units is 50m
  • -    Maximum height difference between internal units is 15m

OPTIMAL CONTROL OF LUBRICATION OIL RETRIEVAL

The digital scroll compressor while compressing ensures sufficient flow of the refrigerant so that the oil returns to the compressor together with the refrigerant. The compressor always works with maximum power, the refrigerant gains great speed which enables the return of the oil into the compressor, even at the places where oil usually percipitates. During idle time the oil does not get out of  the compressor. 
By combining electronic and mechanical regulation, optimal oil level in the compressor trunk case and oil recirculation during compression and idle time are constantly maintained.