[Mechanical Equipment Technology Edition] Daily Question 201803030: Gas flow regulation mechanism of screw refrigeration compressors (4)
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This post was last edited by YORK Industrial Refrigeration on 2018-4-2 at 10:39. This year’s 【Daily Question】is divided into three categories: screw refrigeration compressors, refrigeration systems, and oil circuit systems, aiming to provide a comprehensive understanding of refrigeration technology. (If you encounter something you don’t know or can’t answer, please actively look up information; as you do so, your skills will improve!) ) All participants in the comments on this post will receive 1-3 wealth points; those who give complete answers will get 10-15 points, with the validity period being two days. ============================== Screw refrigeration compressor gas flow control mechanism (4): What is the function of the area marked with a red circle? (Analysis based on Figure 2) Answer: Name: Spool valve. Red circle: Radial exhaust port, used to determine the fixed volume ratio (Figure 1) (Figure 2) ============================== High-quality promotions: Mobile equipment——Videos on the repair and adjustment of York compressors https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1806833 Mobile equipment——Maintenance procedures for York screw compressors https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1806833 Mobile equipment——Upgrading of York Quinton control centers https://bbs.hcbbs.com/thread-1804837-1-1.html Mobile equipment——Major repairs of GEA Grasox screw compressors https://bbs.hcbbs.com/thread-1800467-1-1.html Mobile equipment——Disassembly and maintenance of British HOWDEN screw compressors https://bbs.hcbbs.com/thread-1832529-1-1.html Mobile equipment——Disassembly and maintenance of Japanese Maekawa MYCOM screw compressors https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=
The circled area should be the exhaust port; adjusting the volume ratio inside the refrigeration unit is done by referring to this circled area
The area marked with a red circle is the sliding notch of the slide valve. When the slide valve has not moved yet, its rear edge is in close contact with the bottom edge of the sliding groove on the housing, while its front edge together with the remaining area of the sliding groove forms a radial exhaust port. At this time, the inflation is greatest in the elemental volume. The gas drawn in from the intake side is compressed by the rotor and then completely discharged from the exhaust port, with 100% of its energy retained. When high-pressure oil pushes the oil piston and spool in the direction of the discharge end, the rear edge of the spool is pushed away from the bottom edge of the fixed sliding notch, creating a passage that leads to the radial suction port and allows gas to escape during compression. This reduces the working length of the screw, thereby decreasing the volume of gas that is drawn in. Less gas is discharged, and the gas that is drawn in enters the suction side of the compressor through the bypass port before it can be compressed (since the contact line has not yet been closed). As a result, the amount of gas drawn in and the flow rate of the refrigerant are reduced, thereby serving as a means of energy regulation. The size of the vent channel depends on the amount of exhaust gas required. The area of the exhaust port formed by the leading edge of the slide valve and the sliding notch (i.e., the radial orifice) decreases simultaneously, thereby achieving the purpose of changing the exhaust volume. At this point, the adjustment indicator pointer shows the corresponding percentage change in displacement. As the slide valve continues to move toward the discharge end, the cooling capacity decreases continuously as the discharge volume reduces. Thus, the energy can be adjusted steplessly. When the vent channel approaches the exhaust opening, the working length of the screw approaches zero, thereby enabling unloading during startup.
Gas in the high-pressure element volume leaks into the lower-pressure element volume; the shape of the leakage surface is similar to that of a triangular spatial surface, and it is called the leakage triangle, also known as axial leakage. It serves to exhaust air and relieve pressure.
This should be a vent port, serving to regulate the backflow volume of the compressor
Gas in the high-pressure element volume leaks into the lower-pressure element volume; the shape of the leakage surface is similar to that of a triangular spatial surface, and it is called the leakage triangle, also known as axial leakage. It serves to exhaust air and relieve pressure.
Gas in the high-pressure element volume leaks into the lower-pressure element volume; the shape of the leakage surface is similar to that of a triangular spatial surface, and it is called the leakage triangle, also known as axial leakage. It serves to exhaust air and relieve pressure.
Gas in the high-pressure element volume leaks into the lower-pressure element volume; the shape of the leakage surface is similar to that of a triangular spatial surface, and it is called the leakage triangle, also known as axial leakage. It serves to exhaust air and relieve pressure.