Two-stage screw compressor and air conditioning unit

Abstract

The application provides a double-stage screw compressor and an air conditioning unit. The double-stage screw compressor comprises a shell, a partition plate, a low-pressure stage rotor pair and a high-pressure stage rotor pair. The double-stage screw compressor and the air conditioning unit provided by the application are provided with a gas supplementing structure on the high-pressure stage shell, so as to overcome the problem that the double-stage screw compressor cannot be provided with the gas supplementing structure in the prior art due to the absence of a shaft coupling, and the gas supplementing outlet of the gas supplementing structure faces the partition plate, so that the exhaust gas of the low-pressure stage shell and the gas supplementing gas of the gas supplementing structure are relatively collided, so as to mix the exhaust gas and the gas supplementing gas as soon as possible, stabilize the suction pressure of the high-pressure stage rotor pair, and avoid the occurrence of the surge phenomenon of the high-pressure stage rotor pair, so as to ensure the operation reliability of the compressor under the premise of ensuring the reliability of the gas supplementing, reduce the inter-stage pressure pulsation loss, and improve the compressor efficiency.

Description

Technical Field

[0001] This invention relates to the field of air handling equipment technology, and in particular to a two-stage screw compressor and an air conditioning unit. Background Technology

[0002] The coaxial direct-drive rotor is a new structure for screw compressors proposed in recent years. It achieves two-stage compression through only a pair of rotors. Compared with single-unit two-stage compressors, its structure is more streamlined, reducing the number of couplings and bearings, thereby reducing compressor transmission losses and showing great promise for future applications.

[0003] Currently, in conventional single-unit two-stage compressors, a coupling is installed between the first-stage and second-stage compression structures, and the gas injection port can be located at the coupling position to achieve the purpose of gas injection to the second-stage compression structure. However, the distance between the low-pressure stage and the high-pressure stage of a coaxial direct-drive screw compressor is very short, and a coupling is not required for connection. There is no space to arrange a conventional gas injection chamber, so the gas injection technology of the two-stage screw compressor cannot be directly applied, resulting in the problem of not being able to inject gas into the two-stage screw compressor. Summary of the Invention

[0004] To address the technical problem of the inability to replenish gas in existing two-stage screw compressors, a two-stage screw compressor and air conditioning unit with a gas replenishment structure installed on the high-pressure stage housing are provided.

[0005] A two-stage screw compressor, comprising:

[0006] case;

[0007] A spacer plate that divides the housing into interconnected low-pressure stage housings and high-pressure stage housings;

[0008] Low-pressure stage rotor pair, wherein the low-pressure stage rotor pair is disposed within the low-pressure stage housing;

[0009] A high-pressure stage rotor pair, wherein the high-pressure stage rotor pair is disposed within the high-pressure stage housing;

[0010] The male rotor of the low-pressure stage rotor pair is coaxially arranged with the male rotor of the high-pressure stage rotor pair, and the female rotor of the low-pressure stage rotor pair is coaxially arranged with the female rotor of the high-pressure stage rotor pair.

[0011] The high-pressure stage housing is provided with a gas replenishment structure, and the gas replenishment outlet of the gas replenishment structure faces the spacer plate.

[0012] The partition plate is provided with a communication port, and the air supply outlet faces the communication port.

[0013] A gas replenishment chamber is provided on the high-pressure stage housing, and the gas replenishment chamber constitutes the gas replenishment structure.

[0014] The thickness of the sidewalls of the air replenishment chamber facing the interior of the high-pressure stage housing is equal.

[0015] The high-pressure stage housing is provided with a gas inlet, and the gas inlet chamber is connected to an external gas source through the gas inlet.

[0016] The air supply outlet is located on the side wall of the air supply chamber facing the partition plate, and the air supply inlet is located on the side wall of the air supply chamber away from the interior of the housing.

[0017] The relationship between the volume A of the air replenishment chamber, the air replenishment volume flow rate Q1 at the air replenishment inlet, and the exhaust volume flow rate Q2 of the low-pressure stage shell is Q1*t+Q2*t≤A≤1.5(Q1*t+Q2*t).

[0018] Where t is the time it takes for the high-pressure stage rotor to rotate through one tooth slot of the middle anode rotor.

[0019] The flow velocity range of the gas replenishment outlet is 8 m / s to 10 m / s.

[0020] The compressor also includes a drive mechanism, which is connected to the low-pressure stage rotor.

[0021] An air conditioning unit includes the aforementioned two-stage screw compressor.

[0022] The two-stage screw compressor and air conditioning unit provided by this invention have a gas injection structure on the high-pressure stage housing, thereby overcoming the problem that the two-stage screw compressor does not have a coupling and therefore cannot arrange the gas injection structure in the prior art. Moreover, the gas injection outlet of the gas injection structure faces the partition plate, so that the exhaust gas from the low-pressure stage housing and the gas injection gas of the gas injection structure are opposite to each other, thereby quickly mixing the exhaust gas and the gas injection gas. This stabilizes the intake pressure of the high-pressure stage rotor pair and avoids phenomena such as surge in the high-pressure stage rotor pair. Thus, while ensuring reliable gas injection, the reliable operation of the compressor is guaranteed, thereby reducing interstage pressure pulsation loss and improving compressor efficiency. Attached Figure Description

[0023] Figure 1 A cross-sectional view of a compressor provided in an embodiment of the present invention;

[0024] Figure 2 Another cross-sectional view of the compressor provided in an embodiment of the present invention;

[0025] In the picture:

[0026] 1. Housing; 11. Spacer plate; 12. Low-pressure stage housing; 13. High-pressure stage housing; 41. Low-pressure stage rotor pair; 42. High-pressure stage rotor pair; 5. Air supply chamber; 51. Air supply inlet. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0028] like Figure 1 and Figure 2 The two-stage screw compressor shown includes: a housing 1; a partition plate 11 that divides the housing 1 into a low-pressure stage housing 12 and a high-pressure stage housing 13 that are in communication with each other; a low-pressure stage rotor pair 41 disposed within the low-pressure stage housing 12; and a high-pressure stage rotor pair 42 disposed within the high-pressure stage housing 13. The male rotor of the low-pressure stage rotor pair 41 and the male rotor of the high-pressure stage rotor pair 42 are coaxially arranged, and the female rotor of the low-pressure stage rotor pair 41 and the female rotor of the high-pressure stage rotor pair 42 are coaxially arranged. A gas supply structure is provided on the high-pressure stage housing 13, and the gas supply outlet of the gas supply structure faces the partition plate 11. A gas-injection structure is installed on the high-pressure stage housing 13 to overcome the problem that the two-stage screw compressor cannot accommodate the gas-injection structure as in the prior art due to the lack of a coupling. Furthermore, the gas-injection outlet of the gas-injection structure faces the partition plate 11, ensuring that the exhaust gas from the low-pressure stage housing 12 and the gas-injection from the gas-injection structure are oppositely opposed. This allows for rapid mixing of the exhaust gas and gas-injection, stabilizing the suction pressure of the high-pressure stage rotor on 42 and preventing surge phenomena. Thus, while ensuring reliable gas injection, the compressor's operational reliability is guaranteed, reducing interstage pressure pulsation losses and improving compressor efficiency.

[0029] The partition plate 11 is provided with a connecting port, and the gas supply outlet faces the connecting port. The high-pressure stage housing 13 and the low-pressure stage housing 12 are connected through the connecting port, that is, the connecting port constitutes the exhaust port of the low-pressure stage housing 12. At this time, the airflow from the gas supply outlet collides head-on with the exhaust from the low-pressure stage housing 12, achieving a counter-current effect, which allows the gases to quickly merge. Finally, the pressure of the gas drawn into the high-pressure stage rotor 42 is stabilized, ensuring the compression effect of the high-pressure stage rotor on 42, thereby reducing interstage pressure pulsation loss and improving compressor efficiency.

[0030] In one embodiment, a gas replenishment chamber is provided on the high-pressure stage housing 13, which constitutes the gas replenishment structure. The gas used for replenishment can be first delivered to the gas replenishment chamber, and after the gas pressure is stabilized in the gas replenishment chamber, it is discharged from the gas replenishment chamber, thereby further ensuring the stability of the intake pressure of the high-pressure stage rotor on 42 and ensuring the compression effect of the high-pressure stage rotor on 42.

[0031] The relationship between the volume A of the replenishing chamber and the replenishing gas volume flow rate Q1 of the replenishing gas inlet 51 and the exhaust gas volume flow rate Q2 of the low-pressure stage housing 12 is Q1*t + Q2*t ≤ A ≤ 1.5(Q1*t + Q2*t); where t is the time it takes for the high-pressure stage rotor to rotate through one tooth slot of the male rotor in 42. Due to the limitations of the compressor structure, A cannot be too large. When A is too small, the replenishing gas and the exhaust gas from the low-pressure stage housing 12 cannot be fully mixed, resulting in severe pulsation of the suction pressure in the high-pressure stage housing 13, which seriously affects the compression efficiency of the compressor. Only when A is within the range of Q1*t + Q2*t ≤ A ≤ 1.5(Q1*t + Q2*t) can the volume of the replenishing chamber be guaranteed to meet the requirements for sufficient mixing of the replenishing gas and the exhaust gas from the low-pressure stage housing 12, and the problem of decreased suction pressure in the high-pressure stage housing 13 of the compressor can be avoided.

[0032] To ensure the effective gas supply from the gas supply chamber to the high-pressure stage housing 13, the areas of the gas supply inlet 51 and the gas supply outlet need to be matched with the gas supply flow rate, ensuring that the flow velocity at the gas supply outlet is within the range of 8 m / s to 10 m / s. That is, the ratio of the gas supply flow rate to the sum of the areas of the gas supply inlet 51 and the gas supply outlet needs to be within the range of 8 m / s to 10 m / s. If the flow velocity is too low, the gas supply effect to the high-pressure stage housing 1 cannot be guaranteed; if the flow velocity is too high, it will affect the exhaust from the low-pressure stage housing 12, thus affecting the compressor's operating efficiency.

[0033] To ensure the structural strength of the high-pressure stage housing 13 while maximizing the volume of the air replenishment chamber, the thickness of the sidewalls of the air replenishment chamber facing the interior of the high-pressure stage housing 13 is equal. That is, the sidewalls of the air replenishment chamber facing the interior of the high-pressure stage housing 13 are designed to conform to the internal sidewalls of the corresponding portion of the high-pressure stage housing 13. This ensures reliable structural strength of the high-pressure stage housing 13 while maximizing the volume of the air replenishment chamber, thereby guaranteeing sufficient air replenishment and ensuring the effective air replenishment of the compressor.

[0034] The high-pressure stage housing 13 is provided with a gas replenishment inlet 51, and the gas replenishment chamber is connected to an external gas source through the gas replenishment inlet 51. The gas replenishment inlet 51 is located on the side wall of the gas replenishment chamber away from the interior of the high-pressure stage housing 13. The external gas source can be directly connected to the gas replenishment inlet 51 outside the high-pressure stage housing 13 and supply replenishment gas to the gas replenishment chamber.

[0035] In one embodiment, the air supply outlet is located on the side wall of the air supply chamber facing the spacer 11, and the air supply inlet 51 is located on the side wall of the air supply chamber away from the interior of the housing 1.

[0036] The compressor also includes a drive mechanism connected to the low-pressure stage rotor pair 41.

[0037] An air conditioning unit includes the aforementioned two-stage screw compressor.

[0038] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A two-stage screw compressor, characterized in that: include: Shell (1); A spacer (11) divides the housing (1) into a low-pressure stage housing (12) and a high-pressure stage housing (13) that are in communication with each other. Low-pressure stage rotor pair (41), the low-pressure stage rotor pair (41) is disposed inside the low-pressure stage housing (12); High-pressure stage rotor pair (42), the high-pressure stage rotor pair (42) is disposed inside the high-pressure stage housing (13); The male rotor of the low-pressure stage rotor pair (41) is coaxially arranged with the male rotor of the high-pressure stage rotor pair (42), and the female rotor of the low-pressure stage rotor pair (41) is coaxially arranged with the female rotor of the high-pressure stage rotor pair (42). The high-pressure stage housing (13) is provided with a gas replenishment structure, and the gas replenishment outlet of the gas replenishment structure faces the spacer plate (11). The high-pressure stage housing (13) is provided with an air supply chamber (5), which constitutes the air supply structure; The high-pressure stage housing (13) is provided with a gas inlet (51), and the gas inlet chamber (5) is connected to an external gas source through the gas inlet (51); The relationship between the volume A of the air replenishment chamber (5), the air replenishment volume flow rate Q1 of the air replenishment inlet (51), and the exhaust volume flow rate Q2 of the low-pressure stage shell (12) is Q1*t+Q2*t≤A≤1.5(Q1*t+Q2*t). Where t is the time it takes for the high-pressure stage rotor to rotate through one tooth slot of the middle yang rotor.

2. The two-stage screw compressor according to claim 1, characterized in that: The partition plate (11) is provided with a communication port, and the air supply outlet faces the communication port.

3. The two-stage screw compressor according to claim 1, characterized in that: The thickness of the sidewall of the air replenishment chamber (5) facing the interior of the high-pressure stage housing (13) is equal.

4. The two-stage screw compressor according to claim 1, characterized in that: The air supply outlet is located on the side wall of the air supply chamber (5) facing the partition plate (11), and the air supply inlet (51) is located on the side wall of the air supply chamber (5) away from the interior of the housing (1).

5. The two-stage screw compressor according to claim 1, characterized in that: The flow velocity range of the gas replenishment outlet is 8 m / s to 10 m / s.

6. The two-stage screw compressor according to claim 1, characterized in that: The compressor also includes a drive mechanism connected to the high-pressure stage rotor pair (41).

7. An air conditioning unit, characterized in that: The two-stage screw compressor includes any one of claims 1 to 6.

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