Danfoss TGH285, Руководство по применению и установке

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Chapter 13.0 System Design Guidelines
In addition to the instructions detailed in the technical documentation set, this section provides basic guidelines
and requirements for the design and manufacture of systems equipped with Danfoss Turbocor compressors.
NOTE
The compressor internal safety control settings are designed to provide protection for the compressor only. Designers MUST provide
SYSTEM protection within their control design. Danfoss LLC will not be responsible for system protection other than the compressor.
13.1 General Requirements
1. Check for compliance with all installation, operating, commissioning, and service steps, as outlined in
the documentation set. Check for the appropriate operating envelope and minimum unloading
capacity for the intended application.
2. System components such as evaporators, condensers, valves, etc., should be properly selected and
sized for appropriate performance and compatibility with applied refrigerant.
3. The system suction and discharge piping should be properly designed and selected for minimum
pressure drop. Since the Turbocor compressor operates without lubricating oil, conventional piping
considerations that ensure oil return, such as multiple risers and traps, are not required. In most cases,
larger diameter lines will result in better compressor performance and efficiency.
4. For improved efficiency and better control, particularly at low load/low compression ratios, EXVs are
strongly recommended. To take advantage of low pressure ratio operation to improve low load
performance and efficiency, EXV capacity should be selected accordingly. Thermal expansion valves
(TXVs) are not recommended due to the general inability of these devices to adequately cover the
operating spectrum of centrifugal compressors, particularly at low compression ratios.
5. Take all necessary precautions to prevent any possibility of liquid floodback to the compressor. This
means consideration during the ON and OFF cycles, particularly in multiple compressor installations.
This WILL include, but is not limited to, the inclusion of a liquid line solenoid valve and piping,
evaporator and condenser arranged in a manner that prevents free drainage of liquid to compressor.
6. The refrigeration piping system must be clean and free of all debris, in accordance with refrigeration-
industry best practices, as particles can damage the compressor.
7. The system control should not be designed based on pump down cycle. The system cannot be pumped
down due to the surge characteristics of centrifugal compressors.
8. Refer to Table 13-1 Recommended Minimum Copper Tube Size for recommended minimum pipe sizes.
Table 13-1 Recommended Minimum Copper Tube Size
TTS300/TGS230 TTS350/TGS310 TTS400/TGS390 TGS490 TTS700/TGS520 TTH375/TGH285
Suction 4" 4" 5" 5" 5" 4"
Discharge 2 5/8" 3 1/8" 4" 4" 4" 3 1/8"
NOTE
If steel pipe is used, the pipe must be selected to give the equivalent inside diameter to copper pipe.
Properly tapered trumpets with smooth transitions must be used to connect the compressor flanges to the
pipework.
The discharge line exit transition should not be at an angle greater than eight 8° inclusive. The suction line length
should be straight for 1.5 times the pipe diameter before entry into the compressor.
M-AP-001-EN Rev. S-9/8/2021 Page 75 of 136