CN219242207U

CN219242207U - Capacity adjusting mechanism of single-machine double-stage screw compressor

Info

Publication number: CN219242207U
Application number: CN202223532002.4U
Authority: CN
Inventors: 蒋恪勤; 林群; 张恩启; 董翔
Original assignee: HANGZHOU JIUYI MACHINERY CO Ltd
Current assignee: HANGZHOU JIUYI MACHINERY CO Ltd
Priority date: 2022-12-29
Filing date: 2022-12-29
Publication date: 2023-06-23
Anticipated expiration: 2032-12-29

Abstract

The utility model relates to a capacity adjusting mechanism of a single-machine double-stage screw compressor. The utility model comprises a high-pressure-stage capacity adjusting slide valve and a slide valve rod, wherein one end of the slide valve rod is fixed on the high-pressure-stage capacity adjusting slide valve, an intermediate pressure area is arranged between one end of a low-pressure-stage rotor and one end of the high-pressure-stage rotor, and the other end of the low-pressure-stage rotor and the other end of the high-pressure-stage rotor are respectively a low-pressure area and a high-pressure area, and the utility model is characterized in that: the hydraulic oil cylinder is characterized by further comprising a two-position three-way electromagnetic valve and an oil cylinder provided with an oil piston, wherein the other end of the sliding valve rod is fixed on the oil piston of the oil cylinder, the two-position three-way electromagnetic valve is provided with an air inlet, an air outlet and an air outlet, the air inlet is communicated with the middle pressure area through a connecting pipe, the air outlet is connected with the oil cylinder through a connecting pipe, and the air outlet is communicated with the high pressure area through a connecting pipe. The utility model solves the problem that the middle pressure of the single-machine double-stage screw compressor is continuously increased at the initial stage of starting the small pressure ratio to cause the high-pressure slide valve to unload so as to cause the middle pressure to be increased and alarm and stop.

Description

Capacity adjusting mechanism of single-machine double-stage screw compressor

Technical Field

The utility model relates to a component in a screw compressor, in particular to a capacity adjusting mechanism of a single-machine double-stage screw compressor, and belongs to the technical field of fluid machinery.

Background

In practical applications, a single-stage two-stage screw compressor may be required to have a capacity adjustment function. The capacity adjustment function can be generally achieved by various methods, such as a variable frequency motor for changing the displacement by adjusting the rotational speed of the screw rotor, and a capacity adjusting slide valve for changing the effective working section length of the rotor, as shown in fig. 1 and 2.

When the two schemes are used in a single-machine double-stage screw compressor, the respective disadvantages exist. When using a variable frequency motor, the system needs to be configured with a dedicated frequency converter, adding additional cost. When both low pressure stage and high pressure stage rotors employ capacity modulating slide valves, relatively complex low and high pressure stage displacement matching systems and electronic control systems may be required. The low-pressure and high-pressure stage displacement matching of the common single-machine double-stage screw compressor is designed for the working conditions of full-load displacement and larger pressure difference, namely, the ratio of the suction volume flow of the low-pressure stage to the suction volume flow of the high-pressure stage is about 2:1, so that the performance advantage of two-stage compression is exerted.

There is also a relatively good technology at present, for example, chinese patent publication No. CN205172954U discloses an automatic unloading starting mechanism for a screw compressor, and the unloading slider is pushed out by a spring, so that the displacement is reduced, and the motor is ensured to start under light load during startup. However, when the scheme is used for the high-pressure stage of the single-machine double-stage screw compressor, in some applications, a small pressure ratio and a large flow are needed at the initial starting stage, the suction and discharge pressure difference is small, the actual internal volume is small at the moment, the flow of the low-pressure stage discharge volume is large, the suction volume flow of the high-pressure stage is constant, the intermediate pressure is gradually increased, when the intermediate pressure is increased to be close to the discharge pressure, the pressure difference acting on the two sides of the high-pressure stage slide valve is insufficient to overcome the spring force, and the high-pressure stage slide valve is unloaded, so that the intermediate pressure is continuously increased until an alarm is stopped.

Therefore, at present, no single-machine double-stage screw compressor capacity adjusting mechanism has a simple structure, reasonable design and convenient use, and can effectively solve the problem that the single-machine double-stage screw compressor is warned to stop due to the fact that the middle pressure is continuously increased when the single-machine double-stage screw compressor is started at the initial stage of a small pressure ratio so that the high-pressure-stage slide valve is unloaded.

Disclosure of Invention

The utility model aims to overcome the defects in the prior art, and provides the capacity adjusting mechanism of the single-machine double-stage screw compressor, which has the advantages of simple structure, reasonable design and convenient use, and can effectively solve the problem that the middle pressure of the single-machine double-stage screw compressor is continuously increased in the initial stage of starting the small pressure ratio so that the high-pressure-stage slide valve is unloaded to cause the middle pressure to be increased to alarm and stop.

The utility model solves the problems by adopting the following technical scheme: the single-machine double-stage screw compressor capacity adjusting mechanism comprises a low-pressure-stage rotor, a high-pressure-stage rotor, a low-pressure-stage capacity adjusting slide valve, a high-pressure-stage capacity adjusting slide valve and a slide valve rod, wherein the low-pressure-stage rotor is matched with the low-pressure-stage capacity adjusting slide valve, the high-pressure-stage rotor is matched with the high-pressure-stage capacity adjusting slide valve, one end of the slide valve rod is fixed on the high-pressure-stage capacity adjusting slide valve, an intermediate pressure area is arranged between one end of the low-pressure-stage rotor and one end of the high-pressure-stage rotor, and the other end of the low-pressure-stage rotor and the other end of the high-pressure-stage rotor are respectively a low-pressure area and a high-pressure area, and the single-machine double-stage screw compressor capacity adjusting mechanism is structurally characterized in that: the hydraulic oil cylinder is characterized by further comprising a two-position three-way electromagnetic valve and an oil cylinder provided with an oil piston, wherein the other end of the sliding valve rod is fixed on the oil piston of the oil cylinder, the two-position three-way electromagnetic valve is provided with an air inlet, an air outlet and an air outlet, the air inlet is communicated with the middle pressure area through a first connecting pipe, the air outlet is connected with the oil cylinder through a second connecting pipe, and the air outlet is communicated with the high pressure area through a third connecting pipe.

Preferably, when the two-position three-way electromagnetic valve is powered off, the oil cylinder is communicated with the middle pressure area; when the two-position three-way electromagnetic valve is powered on, the oil cylinder is communicated with the high-pressure area.

Compared with the prior art, the utility model has the following advantages and effects: the high-pressure-stage capacity regulating slide valve is connected with the slide valve rod and the oil piston into a whole, and the oil pressure in the oil cylinder is controlled to be high pressure or intermediate pressure through the power supply and the power failure of a two-position three-way electromagnetic valve, so that the resultant force direction of the whole assembly of the slide valve and the oil piston is changed, the oil piston moves, the capacity regulating control of the high-pressure-stage capacity regulating slide valve is actively carried out, and the high-pressure-stage capacity regulating slide valve is simple in structure, ingenious in conception and very convenient to operate. Through the adjusting structure, the problem that the middle pressure is continuously increased in the initial stage of the small pressure ratio starting of the single-machine double-stage screw compressor, so that the high-pressure slide valve is unloaded to cause the middle pressure to be increased to give an alarm and stop can be effectively solved.

The utility model can meet the working conditions of small pressure ratio and large flow rate at the initial starting stage without matching control of a plurality of electromagnetic valves, and the suction pressure difference and the exhaust pressure difference are small at the moment, but the high-pressure-stage capacity adjusting slide valve can actively control loading, even if the displacement of a low-pressure stage is fully loaded, the middle pressure is not increased to cause alarm shutdown, and the pressure is at most only equal to high pressure, which is equivalent to single-stage compression, and the high-pressure-stage rotor does not increase the pressure.

Drawings

In order to more clearly illustrate the embodiments of the utility model and/or the technical solutions of the prior art, the drawings that are required in the description of the embodiments and/or the prior art will be briefly described below, it being obvious that the drawings in the description below are only some embodiments of the utility model and that other drawings may be obtained from these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic diagram of a prior art fully loaded structure.

Fig. 2 is a schematic diagram of a prior art partial load configuration.

Fig. 3 is a schematic diagram of a capacity adjustment mechanism of a single-unit two-stage screw compressor in accordance with an embodiment of the present utility model.

In the figure: 1-a low pressure stage rotor; 2-high pressure stage rotor; 3-low pressure stage capacity modulating slide valve; 4-high pressure stage capacity modulating slide valve; 5-a slide valve rod; 6-oil piston; 7-an oil cylinder; 8-two-position three-way electromagnetic valve; 10-low pressure zone; 11-an intermediate pressure zone; 12-high pressure zone; 13-connecting pipe I; a 14-second connecting pipe; 15-connecting pipes III; p-inlet; a-an air outlet; r-exhaust port.

Detailed Description

The present utility model will be described in further detail by way of examples with reference to the accompanying drawings, which are illustrative of the present utility model and not limited to the following examples.

Examples

Referring to fig. 3, the capacity adjusting mechanism of the single-machine two-stage screw compressor in the present embodiment includes a low-pressure stage rotor 1, a high-pressure stage rotor 2, a low-pressure stage capacity adjusting slide valve 3, a high-pressure stage capacity adjusting slide valve 4, a slide valve rod 5, a two-position three-way electromagnetic valve 8 and an oil cylinder 7, wherein an oil piston 6 is installed in the oil cylinder 7, and the oil piston 6 can move in the oil cylinder 7 under the action of external force.

The low-pressure stage rotor 1 and the low-pressure stage capacity adjusting slide valve 3 in the embodiment are matched, the high-pressure stage rotor 2 and the high-pressure stage capacity adjusting slide valve 4 are matched, an intermediate pressure area 11 is arranged between one end of the low-pressure stage rotor 1 and one end of the high-pressure stage rotor 2, the other end of the low-pressure stage rotor 1 is a low-pressure area 10, and the other end of the high-pressure stage rotor 2 is a high-pressure area 12.

In this embodiment, one end of the spool rod 5 is fixed on the high-pressure-stage capacity-adjusting spool valve 4, the other end of the spool rod 5 is fixed on the oil piston 6 of the oil cylinder 7, and the high-pressure-stage capacity-adjusting spool valve 4, the spool rod 5 and the oil piston 6 are connected as a whole.

The two-position three-way electromagnetic valve 8 in the embodiment is provided with an air inlet P, an air outlet A and an air outlet R, wherein the air inlet P is communicated with the middle pressure area 11 through a first connecting pipe 13, the air outlet A is connected with the oil cylinder 7 through a second connecting pipe 14, and the air outlet R is communicated with the high pressure area 12 through a third connecting pipe 15.

When the two-position three-way electromagnetic valve 8 is powered off, the oil cylinder 7 is communicated with the middle pressure area 11, the pressure in the oil cylinder 7 is approximately equal to the middle pressure of the middle pressure area 11, and the high-pressure-stage capacity adjusting slide valve 4 is unloaded due to the fact that the sectional area of the oil piston 6 is larger than the sectional area of the high-pressure-stage capacity adjusting slide valve 4 and the whole assembly of the high-pressure-stage capacity adjusting slide valve 4 is stressed. When the two-position three-way electromagnetic valve 8 is powered on, the oil cylinder 7 is communicated with the high-pressure area 12, the pressure in the oil cylinder 7 is approximately equal to the high pressure of the high-pressure area 12, and at the moment, the whole component of the high-pressure-stage capacity adjusting slide valve 4 is stressed so that the high-pressure-stage capacity adjusting slide valve 4 is loaded.

In addition, it should be noted that the specific embodiments described in the present specification may vary from part to part, from name to name, etc., and the above description in the present specification is merely illustrative of the structure of the present utility model. All equivalent or simple changes of the structure, characteristics and principle according to the inventive concept are included in the protection scope of the present patent. Those skilled in the art may make various modifications or additions to the described embodiments or substitutions in a similar manner without departing from the scope of the utility model as defined in the accompanying claims.

Claims

1. The utility model provides a unit doublestage screw compressor capacity adjustment mechanism, includes low pressure level rotor (1), high pressure level rotor (2), low pressure level capacity adjustment slide valve (3), high pressure level capacity adjustment slide valve (4) and spool valve (5), low pressure level rotor (1) and low pressure level capacity adjustment slide valve (3) cooperation, high pressure level rotor (2) and high pressure level capacity adjustment slide valve (4) cooperation, the one end of spool valve (5) is fixed on high pressure level capacity adjustment slide valve (4), be intermediate pressure district (11) between the one end of low pressure level rotor (1) and the one end of high pressure level rotor (2), the other end of low pressure level rotor (1) and the other end of high pressure level rotor (2) are low pressure district (10) and high pressure district (12) respectively, its characterized in that: still include two tee bend solenoid valve (8) and install hydro-cylinder (7) of oily piston (6), the other end of slide valve rod (5) is fixed on oily piston (6) of hydro-cylinder (7), two tee bend solenoid valve (8) are provided with air inlet (P), gas outlet (A) and gas vent (R), air inlet (P) are through connecting pipe (13) and intermediate pressure district (11) UNICOM, gas outlet (A) are connected through connecting pipe (14) and hydro-cylinder (7) No. two, gas vent (R) are through connecting pipe (15) No. three and high pressure district (12) UNICOM.

2. The single-unit, two-stage screw compressor capacity modulation mechanism of claim 1, wherein: when the two-position three-way electromagnetic valve (8) is powered off, the oil cylinder (7) is communicated with the middle pressure area (11); when the two-position three-way electromagnetic valve (8) is powered on, the oil cylinder (7) is communicated with the high-pressure area (12).