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CN-122014554-A - Semi-closed reciprocating refrigeration compressor for ammonia

CN122014554ACN 122014554 ACN122014554 ACN 122014554ACN-122014554-A

Abstract

The invention discloses a semi-closed reciprocating refrigeration compressor for ammonia, and relates to the technical field of refrigeration. Comprises a semi-closed shell, a compression mechanism and a driving motor which are arranged in the shell. The stator winding of the driving motor is made of aluminum or aluminum alloy materials so as to resist corrosion of ammonia refrigerants, the compression mechanism is of a reciprocating piston type structure, and the driving motor directly drives the reciprocating piston type compression structure to operate, so that the traditional shaft seal and a coupling are omitted. The crankshaft is also used as a motor shaft, so that direct connection driving is realized. And an integrally formed heat dissipation rib is arranged at the outer part of the shell corresponding to the motor so as to enhance heat dissipation and structural strength. The air suction port is communicated to the motor cavity, so that low-temperature ammonia gas flows through the motor to cool the low-temperature ammonia gas before being compressed. The invention effectively solves the problems of ammonia corrosion and leakage, has the advantages of high sealing performance, high transmission efficiency, low running noise and the like, is particularly suitable for ammonia refrigeration scenes with medium and small cold quantity and high pressure ratio, and fills the technical blank in the field.

Inventors

  • XIA TIAN
  • ZHOU PENG
  • WANG XIAOXIA
  • WANG YONGHUA
  • WANG YUN
  • XIA LINGLI

Assignees

  • 江苏雪梅制冷设备有限公司

Dates

Publication Date
20260512
Application Date
20260205

Claims (7)

  1. 1. A reciprocating refrigeration compressor for semi-closed ammonia comprises a semi-closed shell (10), a compression mechanism (20) and a driving motor (30), wherein the semi-closed shell (10) is internally provided with a containing cavity with a refrigerant suction side and a refrigerant discharge side, the compression mechanism is arranged in the semi-closed shell (10) and is used for compressing ammonia refrigerant, the driving motor (30) is arranged in the semi-closed shell (10) and is in transmission connection with the compression mechanism (20), the driving motor (30) is characterized by comprising a stator assembly (31) and a rotor assembly (32), the stator assembly (31) comprises a stator iron core and a stator winding (311) wound on the stator iron core, the stator winding (311) is made of aluminum or aluminum alloy materials and is used for resisting corrosion of the ammonia refrigerant, the compression mechanism (20) is of a reciprocating piston type compression structure, the ammonia refrigerant is filled in the semi-closed shell (10), and the driving motor (30) is immersed in the atmosphere of the ammonia refrigerant, and the driving motor (30) directly drives the reciprocating piston type compression structure to move to realize the reciprocating piston type compression of the ammonia refrigerant.
  2. 2. The reciprocating compressor for semi-enclosed ammonia according to claim 1, wherein the reciprocating piston type compression structure comprises a crankshaft (40) driven to rotate by a rotor assembly (32) of the driving motor (30), at least one cylinder (21) formed at one side of the semi-enclosed housing (10) or separately provided in the housing, a piston (22) reciprocally movably provided in the cylinder (21), and a connecting rod (23) connected between the piston (22) and the crankshaft (40) to convert a rotational motion of the crankshaft (40) into a reciprocating linear motion of the piston (22), and a bearing (60) provided in the semi-enclosed housing (10) for rotatably supporting the crankshaft (40).
  3. 3. The reciprocating refrigeration compressor for semi-enclosed ammonia according to claim 2, wherein a rotor assembly (32) of said driving motor (30) is directly sleeved and fixed at one end of said crankshaft (40), said crankshaft (40) doubles as a motor shaft of said driving motor (30), a stator accommodating portion is provided at a position of said semi-enclosed housing (10) corresponding to said driving motor (30), and said stator core is fixed at an inner wall of said stator accommodating portion in an interference fit.
  4. 4. A reciprocating refrigeration compressor for semi-enclosed ammonia according to claim 1, characterized in that the surface of the stator winding (311) is coated with an insulating layer made of insulating material resistant to ammonia corrosion.
  5. 5. The reciprocating refrigeration compressor for semi-enclosed ammonia according to claim 1, wherein a plurality of heat dissipation ribs (11) are integrally cast on the outer surface of the semi-enclosed casing (10) at positions corresponding to the driving motor (30), and are used for assisting in dissipating heat generated by the driving motor (30) through natural convection or forced air cooling, the heat dissipation ribs (12) and the semi-enclosed casing (10) are integrally cast through a mold, and the heat dissipation ribs (12) are solid protruding structures formed on the outer wall surface of the casing.
  6. 6. A reciprocating refrigeration compressor for ammonia in semi-enclosed state according to any one of claims 1 to 5, characterized in that said semi-enclosed casing (10) is provided with an air intake and an air exhaust, said air intake being connected to the chamber in which said driving motor (30) is located, so that the ammonia gas at low temperature flows through the stator winding (311) and the rotor assembly (32) of said driving motor (30) before entering said compressing mechanism (20) to cool said driving motor (30).
  7. 7. The reciprocating refrigeration compressor for semi-enclosed ammonia according to claim 2, characterized in that the semi-enclosed housing (10) is further provided with a junction box (50), the outgoing line of the stator winding (311) passes through the housing wall surface and is connected to a binding post in the junction box (50), and the connection part of the outgoing line and the binding post is provided with an ammonia-resistant sealing coating.

Description

Semi-closed reciprocating refrigeration compressor for ammonia Technical Field The invention relates to the technical field of refrigeration compressors, in particular to a semi-closed reciprocating piston refrigeration compressor. Background Ammonia as a natural refrigerant has the advantages of large refrigerating capacity per unit volume, high refrigerating coefficient, low price and the like, and the ozone layer depletion potential value and the global warming potential value are both zero, thus being internationally recognized environment-friendly refrigerant. However, ammonia is toxic, flammable, and strongly irritating odor, and once leaked, can pose a hazard to human health and the surrounding environment. In addition, ammonia has serious corrosion effect on copper and copper alloy, which makes the traditional semi-closed or fully-closed compressor adopting copper enameled wire as motor winding not directly applicable to ammonia refrigeration system. For a long time, in order to avoid ammonia corroding motor windings, ammonia refrigeration compressors have mainly employed open-type structures. I.e. the compressor is separated from the motor, which is located outside the refrigeration system and drives the compressor spindle via a coupling or belt. Although this open structure avoids the motor corrosion problem, it has significant drawbacks: The leakage risk is high, the open type structure is required to be provided with a shaft seal, namely a mechanical seal, at the position where the main shaft penetrates out of the shell, the shaft seal is a dynamic seal part, and ammonia leakage is easy to occur along with operation abrasion or aging, so that potential safety hazards are caused. The device has the advantages of large volume, complex installation, large base for installing the motor and the compressor, accurate centering adjustment and large occupied area. The operation noise is large, and the noise superposition of the shaft coupling transmission and the fan of the external motor leads to higher operation noise of the whole machine. To address the above problems, the industry is beginning to explore semi-enclosed ammonia compressor technology. Solutions have emerged in the prior art for improving the windings of electrical machines using ammonia-resistant materials. For example, chinese patent document CN203430779U discloses a variable frequency high-speed screw refrigerating compressor for semi-closed ammonia, which directly connects with the screw compressor by adopting an aluminum coil permanent magnet variable frequency motor, and utilizes the characteristic of ammonia corrosion resistance of aluminum material to realize semi-closed ammonia compressor, thereby solving the problem of shaft seal leakage. However, such prior art as described above still has the following limitations and disadvantages: There are limitations to the type of construction of the prior art, which is almost all screw compressors. The screw compressor has high efficiency when the displacement is large, but in a small and medium cooling capacity range, the cooling efficiency is significantly reduced due to an increase in the gap leakage relative duty ratio between screw rotors. Therefore, in the application scenes of commercial refrigeration, auxiliary cooling and the like with small and medium power, the screw machine is not the optimal choice. In the prior art, the processing cost and the maintenance threshold are high, the rotor molded line of the screw compressor is complex, the bilateral asymmetric circular arc envelope line has extremely high processing precision requirement, and the manufacturing cost is high. In the prior art, the sealing and energy efficiency problems are solved, the screw machine mainly relies on oil injection to seal the gap of a rotor, and an oil circuit system is complex. In contrast, reciprocating piston compressors have natural advantages in terms of technical maturity, processing costs, and sealing performance under high pressure ratio conditions, particularly in low temperature level applications of small and medium sized refrigerators and cascade refrigeration systems, piston machines remain dominant. In summary, the prior art lacks a semi-closed ammonia refrigeration compressor which can solve the problems of ammonia corrosion and shaft seal leakage and can also give consideration to the advantages of high energy efficiency and low cost under the working condition of medium and small cold. Therefore, the development of the semi-closed compressor combining the ammonia-resistant motor technology and the reciprocating piston type compression structure has important application value. Disclosure of Invention Aiming at the problems of the prior art that an open ammonia compressor has the risk of shaft seal leakage, large volume and high noise, and the existing screw compressor for semi-closed ammonia has low refrigeration efficiency, high processing cost and complex maintenance under the w