CN111852858A - An inner volume ratio adjustment mechanism and a screw compressor with an inner volume ratio adjustable - Google Patents

Abstract

The invention discloses an inner volume ratio adjustment mechanism and a screw compressor with an adjustable inner volume ratio, comprising a screw compressor body, a suction end seat, a suction cavity, a rotor, a slide valve, an exhaust end seat, and a radial exhaust. The screw compressor body is provided with a radial exhaust port, and the plug valve controls the opening and closing of the radial exhaust port; the radial exhaust port and the jacket The exhaust cavity is communicated, and the end of the jacket exhaust cavity is connected with an exhaust pipe. A radial exhaust port and a jacket exhaust cavity are set up at a certain position of the body close to the exhaust end seat, and the opening and closing of the radial exhaust port is controlled by a plug valve. When the plug valve is opened, the gas discharged through the plug valve is discharged from the compressor through the jacket exhaust chamber of the body, and directly enters the oil separator through the inlet of the oil separator. That is, according to the change of the ambient temperature, when the ambient temperature is much lower than the maximum designed ambient temperature, the final exhaust pressure can be reduced by controlling the opening of the plug valve and adjusting the internal volume ratio.

Description

An inner volume ratio adjustment mechanism and a screw compressor with an inner volume ratio adjustable

technical field

The invention relates to the technical field of refrigeration compressors, in particular to an inner volume ratio adjustment mechanism and a screw compressor with an adjustable inner volume ratio.

Background technique

When the twin-screw compressor is working, the inter-tooth volume compresses the gas in the inter-tooth with the rotation of the rotor until the working volume is connected to the edge of the exhaust port. This process is called the internal compression process. When the compression process is over and the exhaust process has just started, the gas pressure in the working volume suddenly decreases or increases because the exhaust pressure and the compression end pressure are not equal under certain working conditions, that is, isovolumetric expansion or isovolumetric compression occurs. Therefore, the final compression pressure in the screw refrigeration compressor is not necessarily equal to the pressure (back pressure) in the discharge chamber. When the pressure at the end of compression is greater than the pressure in the exhaust chamber, it is called overcompression. In this case, the gas is compressed in the working volume from the suction pressure to the pressure at the end of compression, and then expands from the pressure at the end of compression to the discharge pressure. air pressure, and then carry out the exhaust process. When the pressure at the end of compression is less than the pressure in the exhaust chamber, it is called under-compression, and the gas is compressed from the suction pressure to the pressure at the end of compression in the working volume. At this time, the working volume is connected to the exhaust port, and the exhaust pipe The gas in the compressor flows backwards, so that the gas is compressed from the pressure at the end of compression to the exhaust pressure, and then exhausted. In the case of over-compression and under-compression, the heat loss of the compressor is accompanied by the flow loss of the gas and the increase of the periodic exhaust noise, and the power loss of the compressor is increased at the same time. According to the requirements of the application conditions of the compressor, the screw compressor manufacturers in my country propose compressors with different internal volume ratios for selection. However, for units with a wide range of operating conditions, such as summer operating conditions, the ambient temperature is high, and the condensing pressure and condensing temperature of the screw compressor unit are high; the ambient temperature in spring, autumn and winter is low, which is easy to cause the screw refrigeration compressor. The external pressure ratio is not equal, which leads to the phenomenon of over-compression and under-compression, resulting in extra power consumption of the compressor. Therefore, the present invention discloses a screw compressor whose content ratio can be adjusted according to seasonal changes.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an internal volume ratio adjustment mechanism and a screw compressor with an adjustable internal volume ratio, so as to solve the problems existing in the above-mentioned prior art, to adjust the balance of the internal and external pressure ratios of the screw compressor, and to reduce the extra power consumption and improve the working efficiency of the unit.

In order to achieve the above purpose, the present invention provides the following scheme: the present invention provides an inner volume ratio adjustment mechanism, including a radial exhaust port, a plug valve, a jacket exhaust cavity and an exhaust pipe, and the screw compressor body The radial exhaust port is opened at a position close to the exhaust end seat, and the plug valve is arranged at the radial exhaust port and is used to control the opening and closing of the radial exhaust port; on the body of the screw compressor The jacket exhaust cavity communicated with the radial exhaust port is opened, and the end of the jacket exhaust cavity is connected with the exhaust pipe.

Preferably, the position of the radial exhaust port is determined according to the condensing pressure corresponding to the daily average temperature of the winter environment in the place where the screw compressor is used.

Preferably, the condensing pressure and condensing temperature of the screw compressor are calculated according to the daily average temperature of the winter environment where the screw compressor is used, so as to determine the effective working length of the screw corresponding to the condensing pressure when the screw compressor is under 100% capacity load condition, and the The radial position on the compressor body corresponding to the effective working length of the screw is the location of the radial exhaust port.

Preferably, the exhaust pipe communicates with the inlet of the oil separator.

The present invention also provides a screw compressor with an adjustable internal volume ratio, which includes the above-mentioned internal volume ratio adjustment mechanism, and also includes a suction end seat, a suction cavity, a rotor, a slide valve and an exhaust end seat, one side of the body is provided with the suction end seat, one end of the suction cavity in the suction end seat is a suction port, and the other end is communicated with the working cavity in the body; the The rotor and the slide valve are arranged in the inner working chamber of the body, the exhaust end seat is installed on the other side of the body, one end of the exhaust chamber of the exhaust end seat is communicated with the working chamber, and the other end is connected with the working chamber. It is connected to the inlet of the oil separator; under the ambient temperature condition in summer, the inner volume ratio adjustment mechanism does not work, the radial exhaust port is closed, and the refrigerant gas compressed by the compressor passes through the exhaust cavity Enter the oil separator; when the internal and external pressure ratios of the compressor are not equal, the internal volume ratio adjustment mechanism is in working state, the radial exhaust port is opened, and the compressed refrigerant gas is discharged through the jacket. After the air cavity and the exhaust pipe enter the oil separator.

The present invention has achieved the following beneficial technical effects with respect to the prior art:

(1) In the inner volume ratio adjustment mechanism of the present invention, a radial exhaust port is provided on the body, and the setting position of the radial exhaust port is determined according to the daily average temperature of the local winter environment, so that the internal and external pressure ratios are equal, and the screw is compressed. The coefficient of performance of the compressor is improved, and the energy saving of the screw compressor is realized.

(2) The opening and closing of the radial exhaust port is controlled by the plug valve, and the operation is simple, convenient and easy to realize. At the same time, compared with the existing screw compressor, the external structure of the screw compressor has less change.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

Fig. 1 is a structural composition diagram of a screw compressor with an adjustable internal volume ratio;

Fig. 2 is the sectional view of the screw compressor with adjustable internal volume ratio;

Among them, 1. Suction end seat; 2. Suction cavity; 3. Body; 4. Rotor; 5. Exhaust end seat; 6. Slide valve; 7. Exhaust cavity; 8. Radial exhaust port; 9 , plunger valve; 10, jacket exhaust cavity; 11, exhaust pipe.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The purpose of the present invention is to provide an internal volume ratio adjustment mechanism and a screw compressor with an adjustable internal volume ratio, so as to solve the problems existing in the above-mentioned prior art, to adjust the balance of the internal and external pressure ratios of the screw compressor, and to reduce the extra power consumption and improve the working efficiency of the unit.

A radial exhaust port and a jacket exhaust cavity are set up at a certain position of the body near the exhaust end seat, and the opening and closing of the radial exhaust port is controlled by a plug valve. When the plug valve is opened, the gas discharged through the plug valve is discharged from the compressor through the jacket exhaust chamber of the body, and directly enters the oil separator through the inlet of the oil separator. That is, according to the change of the ambient temperature, the internal volume ratio is adjusted by controlling the opening and closing of the plunger valve, so that the internal pressure ratio and the external pressure ratio are equal.

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

As shown in Figures 1-2, this embodiment provides an internal volume ratio adjustment mechanism, including a radial exhaust port 8, a plug valve 9, a jacket exhaust cavity 10 and an exhaust pipe 11. The body of the screw compressor A radial exhaust port 8 is provided on the 3 near the exhaust end seat 5, and a plug valve 9 is arranged at the radial exhaust port 8 and is used to control the opening and closing of the radial exhaust port 8; the body of the screw compressor 3 is provided with a jacket exhaust cavity 10 communicating with the radial exhaust port 8 , and the end of the jacket exhaust cavity 10 is connected to an exhaust pipe 11 .

A radial exhaust port 8 and a jacket exhaust cavity 10 are provided on the body 3 of the screw compressor, and the opening and closing are controlled by a plug valve 9 . The location of the radial exhaust port 8 is mainly determined by the daily average temperature of the local winter environment. Calculate the condensing pressure and condensing temperature of the screw compressor according to the daily average temperature of the local winter environment. Therefore, when the screw compressor is under 100% capacity load condition, the effective working length of the screw corresponding to the condensing pressure is determined, and this point is the position of the radial exhaust port. The body between the radial exhaust port 8 and the exhaust end seat 5 of the screw compressor is provided with a jacket exhaust cavity 10 . An exhaust pipe 11 is arranged at the end of the jacket layer, which is directly connected to the inlet of the oil separator. The refrigerant gas radially discharged through the plug valve 9 enters the oil separator through the body jacket discharge chamber 10 and the discharge pipe 11 .

The present invention also provides a screw compressor with an adjustable internal volume ratio, which includes the above-mentioned internal volume ratio adjustment mechanism, and also includes a suction end seat 1, a suction cavity 2, a rotor 4, a suction end seat 1, a suction cavity 2, a rotor 4, Slide valve 6 and exhaust end seat 5, one side of body 3 is provided with suction end seat 1, one end of suction chamber 2 in suction end seat 1 is a suction port, and the other end is connected with the working chamber in body 3 The rotor 4 and the slide valve 6 are arranged in the inner working cavity of the body 3, the other side of the body 3 is installed with an exhaust end seat 5, one end of the exhaust chamber 7 of the exhaust end seat 5 is communicated with the working chamber, and the other side is connected with the working chamber. One end is connected to the inlet of the oil separator; in the summer ambient temperature condition, the inner volume ratio adjustment mechanism does not work, the radial exhaust port 8 is in a closed state, and the gas compressed by the compressor enters the oil separation through the exhaust chamber 7 In the compressor; when the internal and external pressure ratios of the compressor are not equal (in spring, autumn or winter), the internal volume ratio adjustment mechanism is in working state, the radial exhaust port 8 is opened, and the compressed air is discharged through the jacket. The air chamber 10 and the exhaust pipe 11 then enter the oil separator.

The invention focuses on the adjustment of the final compression pressure of the screw compressor. Under the normal working state of the compressor, the low-temperature and low-pressure refrigerant gas is sucked into the compressor from the suction end seat 1 and the suction chamber 2 of the compressor, and then in the compressor. The airtight space formed by the rotor 4 , the slide valve 6 and the body 3 is compressed into high temperature and high pressure gas, and enters the oil separator through the exhaust end seat 5 and the exhaust pipe 7 . The pressure at the end of compression depends only on the structure of the compressor. Under the ambient temperature condition in summer, the condensing pressure of the screw compressor can reach 1.3MPa, while under the ambient temperature in winter, the condensing pressure is about 0.8MPa, which leads to the unequal internal and external pressure ratio of the compressor, resulting in extra power consumption of the compressor. and energy waste. In the screw compressor of the present invention, a radial exhaust port 8 is provided at a certain position of the body 3 close to the exhaust end seat 5 , and the opening and closing of the orifice is controlled by the plug valve 9 . After the plug valve 9 is opened, the gas discharged through the plug valve 9 is discharged from the compressor through the jacket exhaust cavity 10 of the body 3, and directly enters the oil separator inlet through the exhaust pipe 11 to the oil separator.

The location of the radial exhaust port 8 is mainly determined by the daily average temperature of the local winter environment. Calculate the condensing pressure and condensing temperature of the screw compressor according to the daily average temperature of the local winter environment. Therefore, when the screw compressor is under 100% capacity load condition, the effective working length of the screw corresponding to the condensing pressure is determined, and this point is the position of the radial exhaust port. For example, when designing an ammonia screw compressor, the condensing pressure can reach 1.55MPa when the ambient temperature is 35 degrees Celsius in summer. At this time, the internal volume ratio of the screw compressor is a certain value, and the internal and external pressure ratios are equal. In winter, at a temperature of 10 degrees Celsius, the condensing pressure is 0.75MPa, and the radial exhaust port can be set at the position where the screw is compressed to 0.95MPa. The plug valve 9 is opened, and a part of the gas with a pressure of 0.95MPa is directly discharged from the compressor through the jacket exhaust cavity 10 of the body 3, and directly enters the oil separator inlet through the exhaust pipe 11 to the oil separator, so as to improve the performance of the screw compressor. efficiency and reduce its energy consumption.

It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the above-mentioned exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. . Therefore, the embodiments are to be regarded in all respects as illustrative and not restrictive, and the scope of the invention is to be defined by the appended claims rather than the foregoing description, which are therefore intended to fall within the scope of the claims. All changes that come within the meaning and range of equivalents of , are intended to be embraced within the invention, and any reference signs in the claims shall not be construed as limiting the involved claim.

In the present invention, specific examples are used to illustrate the principles and implementations of the present invention, and the descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention; There will be changes in the specific implementation manner and application scope of the idea of the invention. In conclusion, the contents of this specification should not be construed as limiting the present invention.

Claims (5)

1. An internal volume ratio adjustment mechanism, characterized in that: the screw compressor comprises a radial exhaust port, a plug valve, a jacket exhaust cavity and an exhaust pipe, wherein the radial exhaust port is formed in the position, close to an exhaust end seat, of a machine body of the screw compressor, and the plug valve is arranged at the radial exhaust port and used for controlling the opening and closing of the radial exhaust port; the screw compressor body is provided with the jacket exhaust cavity communicated with the radial exhaust port, and the tail end of the jacket exhaust cavity is connected with the exhaust pipe.

2. The internal volume ratio adjustment mechanism according to claim 1, wherein: the position of the radial exhaust port is determined according to the condensation pressure corresponding to the average daily temperature of the winter environment where the screw compressor is used.

3. The internal volume ratio adjustment mechanism according to claim 2, wherein: and calculating the condensation pressure and the condensation temperature of the screw compressor according to the daily average temperature of the environment where the screw compressor is used in winter, so that the effective working length of the screw corresponding to the condensation pressure is determined when the screw compressor is in a 100% capacity load working condition, and the radial position of the screw compressor corresponding to the effective working length of the screw is the position setting position of the radial exhaust port.

4. The internal volume ratio adjustment mechanism according to claim 1, wherein: the exhaust pipe is communicated with the inlet of the oil separator.

5. A screw compressor having an adjustable internal volume ratio, comprising the internal volume ratio adjusting mechanism according to any one of claims 1 to 4, characterized in that: the screw compressor further comprises a suction end seat, a suction cavity, a rotor, a slide valve and an exhaust end seat which are arranged on a machine body of the screw compressor, wherein the suction end seat is arranged on one side of the machine body, one end of the suction cavity in the suction end seat is a suction port, and the other end of the suction cavity is communicated with a working cavity in the machine body; the rotor and the slide valve are arranged in an internal working cavity of the machine body, the exhaust end seat is arranged on the other side of the machine body, one end of an exhaust cavity of the exhaust end seat is communicated with the working cavity, and the other end of the exhaust cavity of the exhaust end seat is connected with an inlet of the oil separator; under the working condition of summer ambient temperature, the internal volume ratio adjusting mechanism does not work, the radial exhaust port is in a closed state, and refrigerant gas compressed by the compressor enters the oil separator through the exhaust cavity; under the condition that the internal pressure ratio and the external pressure ratio of the compressor are unequal, the internal volume ratio adjusting mechanism is in a working state, the radial exhaust port is opened, and at the moment, compressed refrigerant gas enters the oil separator after passing through the jacket exhaust cavity and the exhaust pipe.

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