CN115467830A - Gas quantity adjusting device and method for two-stage screw compressor - Google Patents
Gas quantity adjusting device and method for two-stage screw compressor Download PDFInfo
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- CN115467830A CN115467830A CN202211135866.4A CN202211135866A CN115467830A CN 115467830 A CN115467830 A CN 115467830A CN 202211135866 A CN202211135866 A CN 202211135866A CN 115467830 A CN115467830 A CN 115467830A
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
- F04C28/08—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by varying the rotational speed
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C23/00—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids
- F04C23/02—Pumps characterised by combination with, or adaptation to, specific driving engines or motors
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
- F04C28/24—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
- F04C28/28—Safety arrangements; Monitoring
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Abstract
The invention provides a two-stage screw compressor air volume adjusting device and an adjusting method thereof, wherein the adjusting device also comprises a first-stage backflow adjusting valve used for adjusting the air volume compressed by the first-stage screw compressor; the secondary backflow regulating valve is used for regulating the compressed air quantity of the secondary screw compressor; the first controller is used for calculating to obtain a first given opening degree according to the measured air inlet pressure value and a first preset set value and controlling the valve to be opened to a first feedback opening degree; the second controller is used for calculating a second given opening degree according to the measured air inlet pressure value and a second preset value and controlling the valve to be opened to a second feedback opening degree; and the third controller is used for comparing the first feedback opening degree and the second feedback opening degree of the first-stage backflow regulating valve and the second-stage backflow regulating valve with the corresponding maximum opening degree and minimum opening degree respectively so as to determine whether the frequency converter needs to be controlled to increase the rotating speed or reduce the rotating speed. The invention has the advantages of wide adaptability, strong system fluctuation resistance, energy consumption reduction and the like.
Description
Technical Field
The invention relates to the technical field of screw compressors, in particular to a gas quantity adjusting device and a gas quantity adjusting method of a two-stage screw compressor.
Background
The two-stage screw compressor is widely applied to the petrochemical industry by the characteristics of large pressure ratio, simple system and less equipment. The shortcomings of the air quantity adjusting method of the two-stage screw compressor are more and more prominent. When the rotating speed of the variable frequency motor is reduced, the air quantity which can be compressed by the first-stage screw compressor and the air quantity which can be compressed by the second-stage screw compressor are not reduced in equal proportion, so that the energy consumption of the motor is increased. The mismatching of the air quantity can cause the mismatching of the interstage pressure of the first-stage screw compressor and the second-stage screw compressor, the pressure ratio of the compressor is increased, and the first-stage screw compressor and the second-stage screw compressor are in abnormal operation states.
The traditional method is to match the air quantities of the first-stage screw compressor and the second-stage screw compressor through calculation, so that the waste of the power of the motor is reduced. The process gas compression device is connected with a driving motor through a proper gear box gear ratio, and the process gas compression is realized under the combined action of the primary screw compressor and the secondary screw compressor. If the function of air volume regulation needs to be realized, the first-stage backflow regulating valve and the second-stage backflow regulating valve are required to perform backflow regulation, and in the backflow regulation process, part of air volume cannot be conveyed to the rear-end pipe network, so that the energy consumption of the motor is increased. When disturbance factors appear in the system and the air input of the primary screw compressor is changed, the air quantity of the secondary screw compressor can be directly influenced, and disturbance is invisibly amplified, so that the traditional adjusting method has higher requirement on the stability of the system. The complex and variable gas flow environment cannot be dealt with. The air quantity adjusting method of the two-stage screw compressor and the air quantity matching degree of the first-stage screw compressor and the second-stage screw compressor become main limitations restricting the use of users.
Disclosure of Invention
The invention provides a gas quantity adjusting device and a gas quantity adjusting method of a two-stage screw compressor, which are used for solving the problem of power waste of a motor caused by mismatching of gas quantities of the two-stage screw compressor in the prior art so as to realize energy conservation.
In a first aspect, the present invention provides a gas amount adjusting device for a two-stage screw compressor, including a driving mechanism, a first-stage screw compressor, a second-stage screw compressor, an inverter motor for driving the first-stage screw compressor and the second-stage screw compressor through the driving mechanism to perform gas compression, and a frequency converter for adjusting a rotation speed of the inverter motor, where the adjusting device further includes:
the first-stage backflow regulating valve is arranged between an inlet and an outlet of the first-stage screw compressor and is used for regulating the compressed air quantity of the first-stage screw compressor;
the secondary backflow regulating valve is arranged between an inlet and an outlet of the secondary screw compressor and is used for regulating the air quantity compressed by the secondary screw compressor;
the first controller is connected with the primary reflux regulating valve and used for calculating a first given opening degree of the primary reflux regulating valve according to the measured air inlet pressure value of the primary screw compressor and a first preset set value and controlling the valve to be opened to a first feedback opening degree;
the second controller is connected with the secondary backflow regulating valve and used for calculating according to the measured air inlet pressure value of the secondary screw compressor and a second preset set value to obtain a second given opening degree of the secondary backflow regulating valve and controlling the valve to be opened to a second feedback opening degree;
and the input end of the third controller is respectively connected with the first controller and the second controller, the output end of the third controller is connected with the frequency converter, and the third controller is used for comparing the first feedback opening degree and the second feedback opening degree of the primary backflow regulating valve and the secondary backflow regulating valve with the corresponding maximum opening degree and minimum opening degree respectively so as to determine whether the frequency converter needs to be controlled to increase the rotating speed or reduce the rotating speed.
In an embodiment of the present invention, the adjusting apparatus further includes a control system, and the third controller is further configured to:
if the PZT1 is larger than the PZT1max and the PZT2 is larger than the PZT2max, controlling the frequency converter to reduce the rotating speed at a first preset speed;
if the PZT1 is less than the PZT1min and the PZT2 is less than the PZT2min, controlling the frequency converter to increase the rotating speed at a second preset speed;
if the PZT is 1min < PZT1< PZT1max or the PZT is 2min < PZT2< PZT2max, controlling the frequency converter to keep the current rotating speed;
the method comprises the steps that PZT1 represents a first feedback opening degree of a primary return regulating valve, PZT2 represents a second feedback opening degree of a secondary return regulating valve, PZT1max represents a maximum opening degree of the primary return regulating valve, PZT1min represents a minimum opening degree of the primary return regulating valve, PZT2max represents a maximum opening degree of the secondary return regulating valve, and PZT2min represents a minimum opening degree of the secondary return regulating valve.
In an embodiment of the present invention, the third controller is further configured to:
comparing the first feedback opening degree of the primary backflow regulating valve with the first given opening degree of the primary backflow regulating valve;
if the difference value between the first preset value and the second preset value is larger than a first preset value, the first-stage backflow regulating valve is prompted to break down, and the first-stage backflow regulating valve and the frequency converter are set to be in a manual state;
comparing a second feedback opening degree of the secondary reflux regulating valve with a second given opening degree of the secondary reflux regulating valve;
and if the difference value of the two is greater than a second preset value, prompting that the secondary backflow regulating valve breaks down, and setting the secondary backflow regulating valve and the frequency converter to be in a manual state.
In an embodiment of the present invention, the primary backflow regulating valve is a pneumatic regulating valve, which includes a first valve opening feedback device for feeding back the valve opening degree; the second-stage backflow regulating valve is a pneumatic regulating valve and comprises a second valve opening degree feedback device for feeding back the valve opening degree.
In an embodiment of the present invention, the adjusting device further includes a first pressure detecting device and a second pressure detecting device, the first pressure detecting device is used for measuring the air inlet pressure of the primary screw compressor, and the second pressure detecting device is used for measuring the air inlet pressure of the secondary screw compressor.
In an embodiment of the present invention, the transmission mechanism is a gear box, an input shaft, a first output shaft, and a second output shaft are disposed inside the gear box, the variable frequency motor is connected to the input shaft and drives the input shaft to rotate, the first output shaft is connected to the primary screw compressor, and the second output shaft is connected to the secondary screw compressor.
In an embodiment of the invention, the first controller, the second controller and the third controller are all programmable logic controllers.
In an embodiment of the present invention, the inlet of the two-stage screw compressor is further used for connecting another gas source.
In a second aspect, the invention further provides an adjusting method of the two-stage screw compressor air volume adjusting device based on the first aspect, where the adjusting method includes:
comparing the first feedback opening and the second feedback opening of the first-stage reflux regulating valve and the second-stage reflux regulating valve with the corresponding maximum opening and minimum opening respectively to determine whether the frequency converter needs to be controlled to increase the rotating speed or decrease the rotating speed;
if the PZT1 is larger than the PZT1max and the PZT2 is larger than the PZT2max, controlling the frequency converter to reduce the rotating speed at a first preset speed;
if the PZT1 is less than the PZT1min and the PZT2 is less than the PZT2min, controlling the frequency converter to increase the rotating speed at a second preset speed;
if the PZT is 1min < PZT1< PZT1max or the PZT is 2min < PZT2< PZT2max, controlling the frequency converter to keep the current rotating speed;
the method comprises the steps that PZT1 represents a first feedback opening degree of a primary return regulating valve, PZT2 represents a second feedback opening degree of a secondary return regulating valve, PZT1max represents a maximum opening degree of the primary return regulating valve, PZT1min represents a minimum opening degree of the primary return regulating valve, PZT2max represents a maximum opening degree of the secondary return regulating valve, and PZT2min represents a minimum opening degree of the secondary return regulating valve.
In an embodiment of the present invention, the adjusting method further includes:
comparing the first feedback opening degree of the primary backflow regulating valve with the first given opening degree of the primary backflow regulating valve;
if the difference value between the first preset value and the second preset value is larger than a first preset value, the first-stage backflow regulating valve is prompted to break down, and the first-stage backflow regulating valve and the frequency converter are set to be in a manual state;
comparing a second feedback opening degree of the secondary backflow regulating valve with a second given opening degree of the secondary backflow regulating valve;
if the difference value between the two is greater than a second preset value, the two-stage backflow regulating valve is prompted to break down, and the two-stage backflow regulating valve and the frequency converter are set to be in a manual state.
Drawings
In order to more clearly illustrate the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a schematic structural diagram of a two-stage screw compressor air quantity adjusting device provided by an embodiment of the invention;
fig. 2 is a schematic flow chart of a method for adjusting the air quantity of a two-stage screw compressor according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.
The terms "first," "second," and the like in the description and claims of the present invention and in the preceding drawings are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that the embodiments described herein may be practiced otherwise than as specifically illustrated or described herein.
In order to solve the problem of motor power waste caused by mismatch of gas amounts of two-stage screw compressors in the prior art, the invention provides a gas amount adjusting device and a gas amount adjusting method of the two-stage screw compressor.
The air quantity adjusting device of the two-stage screw compressor and the adjusting method thereof are described in the following with reference to fig. 1-2.
Referring to fig. 1, fig. 1 is a schematic structural diagram of an air quantity adjusting device of a two-stage screw compressor according to an embodiment of the present invention. The utility model provides a two-stage screw compressor tolerance adjusting device, including one-level screw compressor 1, second grade screw compressor 2, drive mechanism 3, inverter motor 4, converter 5, one-level return-flow control valve 6, second grade return-flow control valve 7, gaseous first entry 8, gaseous second entry 9, gaseous export 10, first pressure measurement device (with the present pressure value PT1 that admits air that surveys show), second pressure measurement device (with the present pressure value PT2 that admits air that surveys show), first controller PY1, second controller PY2 and third controller PY3. Wherein, the primary return-flow regulating valve 6 comprises a first valve opening feedback device (represented by the feedback of the current actual opening, namely the first feedback opening PZT 1), and the secondary return-flow regulating valve 7 comprises a second valve opening feedback device (represented by the feedback of the current actual opening, namely the second feedback opening PZT 2).
Gas enters from a first gas inlet 8 of the primary screw compressor 1, is compressed by the primary screw compressor 1 and is sent to an inlet of the secondary screw compressor 2. The exhaust gas from the first-stage screw compressor 1 is compressed by the second-stage screw compressor 2 and then is delivered to a rear-end pipe network through a gas outlet 10.
The working principle of the gas quantity adjusting device of the two-stage screw compressor is as follows:
first, a first pressure detection device is provided at an intake inlet of the primary screw compressor 1, and detects an intake pressure, and transmits a current intake pressure value PT1 of the primary screw compressor 1 to the first controller PY1. And a second pressure detection device is arranged at the air inlet of the secondary screw compressor 2, detects the air inlet pressure, and transmits the current air inlet pressure value PT2 of the secondary screw compressor 2 to the second controller PY2.
Next, a primary reflux control valve 6 is provided between the inlet and the outlet of the primary screw compressor 1, and the first controller PY1 performs proportional, integral, and differential operations on an input first preset set value PC1 (representing a preset intake pressure value) and PT1 (a current intake pressure value detected by the first pressure detecting device) to obtain a first given opening PV1 of the primary reflux control valve 6. A secondary reflux regulating valve 7 is arranged between an inlet and an outlet of the secondary screw compressor 7, and the second controller PY2 performs proportional, integral and differential operations on an input second preset set value PC2 (representing a preset intake pressure value) and PT2 (a current intake pressure value detected by the second pressure detecting device) to obtain a second given opening PV2 of the primary reflux regulating valve 7.
Then, the primary return-flow regulating valve 6 is provided with a corresponding first valve opening degree feedback device PZT1, and the secondary return-flow regulating valve 7 is also provided with a corresponding second valve opening degree feedback device PZT2. The first valve opening degree feedback device PZT1 and the second valve opening degree feedback device PZT2 are used for feeding back the current valve opening degree to the third controller PY3. The third controller PY3 gives a calculated value to control the output frequency of the frequency converter 5 through calculation and comparison, and the frequency converter 5 drives the frequency conversion motor 4 to operate at a corresponding rotating speed.
That is, the amounts of air compressed by the primary screw compressor 1 and the secondary screw compressor 2 are changed by the output frequency of the inverter 5. The third controller PY3 controls the frequency converter 5 to output frequency, so that the current opening PZT1 of the first-stage backflow regulating valve 6 and the current opening PZT2 of the second-stage backflow regulating valve 7 are in a certain range, and efficient operation of the whole system is guaranteed.
The air quantity adjusting device of the two-stage screw compressor is further described below by combining the working principle.
Illustratively, the primary screw compressor 1 and the secondary screw compressor 2 are both connected to an inverter motor 4 via a transmission 3. The transmission mechanism 3 may be a gear box, and an input shaft, a first output shaft and a second output shaft are arranged inside the gear box. The variable frequency motor 4 is connected with the input shaft and drives the input shaft to rotate, the first output shaft is connected to the first-stage screw compressor 1, and the second output shaft is connected to the second-stage screw compressor 2. The inverter motor 4 drives the first-stage screw compressor 1 and the second-stage screw compressor 2 to compress gas. The frequency converter 5 is connected with the variable frequency motor 4 and is used for adjusting the rotating speed of the variable frequency motor 4. Different rotational speeds can be obtained at the first output shaft and the second output shaft by changing the gear ratio between the gearbox input shaft and the output shaft.
Therefore, the amounts of gas compressed by the primary screw compressor 1 and the secondary screw compressor 2 are determined by the rotational speed of the inverter motor 4. When the rotational speed of the inverter motor 4 is increased, the amount of air compressed by the primary screw compressor 1 and the secondary screw compressor 2 increases. When the rotational speed of the inverter motor 4 is reduced, the amounts of air compressed by the primary screw compressor 1 and the secondary screw compressor 2 are reduced.
Illustratively, the change of the amount of air compressed by the one-stage screw compressor 1 can be obtained by measuring with the first pressure detection device, and assuming that the current value of the intake pressure measured by the first pressure detection device is PT1; the air volume variable pressure of the two-stage screw compressor 2 can also be obtained by measuring with the second pressure detection device, and the current value of the intake pressure measured by the second pressure detection device is assumed to be PT2.
Illustratively, the amount of air compressed by the one-stage screw compressor 1 may be adjusted by the one-stage backflow adjusting valve 6, and the one-stage backflow adjusting valve 6 may be a pneumatic adjusting valve including a first valve opening feedback device for feeding back the degree of opening of the valve, assuming that the first feedback opening of the first valve opening feedback device is PZT1.
For example, the amount of air compressed by the two-stage screw compressor 2 may be adjusted by the two-stage backflow adjusting valve 7, and the two-stage backflow adjusting valve 7 may be a pneumatic adjusting valve including a second valve opening degree feedback device for feeding back the degree of opening of the valve, assuming that the second feedback opening degree of the second valve opening degree feedback device is PZT2.
Illustratively, the first controller PY1 is connected to the primary reflux modulation valve 6, and is configured to calculate a first given opening PV1 of the primary reflux modulation valve 6 according to the intake pressure value PT1 of the primary screw compressor 1 measured by the first pressure detection device and a first preset set value PC1 and control the valve to open to a first feedback opening PZT1.
The primary return flow control valve 6 operates in accordance with the first predetermined opening PV1 and feeds back the current actual opening (i.e., the first feedback opening PZT 1).
Illustratively, the second controller PY2 is connected to the secondary reflux control valve 7, and is configured to calculate a second given opening PV2 of the secondary reflux control valve 7 according to the intake pressure value PT2 of the secondary screw compressor 2 measured by the second pressure detecting device and a second preset setting value PC2 and control the valve to be opened to a second feedback opening PZT2.
The two-stage return flow control valve 7 operates in accordance with the second predetermined opening degree PV2 and feeds back the current actual opening degree (i.e., the second feedback opening degree PZT 2).
Illustratively, the third controller PY3 has inputs respectively connected to the first controller PY1 and the second controller PY2, and an output connected to the frequency converter 5, and is configured to compare the first feedback opening degree and the second feedback opening degree (PZT 1, PZT 2) of the first-stage and second-stage backflow regulating valves (6, 7) with the corresponding maximum opening degree (PZT 1max, PZT2 max) and minimum opening degree (PZT 1min, PZT2 min), respectively, to determine whether to control the frequency converter 5 to increase the rotation speed or decrease the rotation speed.
Specifically, the control procedures of the first controller PY1, the second controller PY2, and the third controller PY3 are described below.
The third controller PY3 is calculated according to the following equation:
if PZT1 is more than PZT1max and PZT2 is more than PZT2max, the frequency converter 5 is controlled to reduce the rotating speed at a first preset speed Fsub (Hz/s);
if PZT1 is less than PZT1min and PZT2 is less than PZT2min, controlling the frequency converter 5 to increase the rotating speed at a second preset speed Fadd (Hz/s);
and if the PZT1min is less than the PZT1< PZT1max or the PZT2min is less than the PZT2< PZT2max, controlling the frequency converter 5 to keep the current rotating speed.
The method comprises the steps that PZT1 represents a first feedback opening degree of a primary return regulating valve, PZT2 represents a second feedback opening degree of a secondary return regulating valve, PZT1max represents a maximum opening degree of the primary return regulating valve, PZT1min represents a minimum opening degree of the primary return regulating valve, PZT2max represents a maximum opening degree of the secondary return regulating valve, and PZT2min represents a minimum opening degree of the secondary return regulating valve.
Illustratively, the first feedback opening PZT1 of the primary return-flow regulating valve 6 is also compared with the first given opening PV1 of the primary return-flow regulating valve 6 by the third controller PY3 or the control system of the system. If the difference value between the two values (namely the difference value between the PZT1 and the PV 1) is larger than the first preset value PZT1dif (for example, the PZT1dif is 3%), the first-stage backflow regulating valve 6 is prompted to have a fault and give an alarm, and the first-stage backflow regulating valve 6 and the frequency converter 5 are set to be in a manual state. And comparing the second feedback opening PZT2 of the secondary backflow regulating valve 7 with a second given opening PV2 of the secondary backflow regulating valve 7, if the difference value (namely the difference value between the PZT2 and the PV 2) between the two is greater than a second preset value PZT2dif, prompting the secondary backflow regulating valve 7 to break down and give an alarm, and setting the secondary backflow regulating valve 7 and the frequency converter 5 to be in a manual state.
Therefore, the valve opening of the primary return regulating valve 6 can be operated within a small range from PZT1min to PZT1max, and the valve opening of the secondary return regulating valve 7 can be operated within a small range from PZT2min to PZT2 max. The output frequency of the frequency converter 5 is adjusted between Fmin and Fmax.
The invention can maintain the matching of the compressed air quantity of the first-stage screw compressor and the second-stage screw compressor, improve the efficiency of the unit, adapt to the working conditions under different air quantities, have strong system fluctuation resistance and can still ensure the normal and stable operation of the unit even under the working conditions with larger air quantity difference.
Furthermore, on the premise of saving cost, the gas quantity selection range of the first-stage screw compressor and the second-stage screw compressor is widened, and the efficiency of the whole machine is improved by using smaller backflow.
In addition, the primary screw compressor and the secondary screw compressor can be independently adjusted in air quantity through corresponding backflow adjusting valves without strictly matching air quantity.
In some embodiments of the present invention, the first controller PY1, the second controller PY2, and the third controller PY3 are all programmable logic controllers, which can implement automatic control and make the device operate dynamically and stably by giving the opening degree of the first-stage and second-stage reflux regulating valves.
In some embodiments of the present invention, the second gas inlet 9 of the two-stage screw compressor 2 is also used for connecting another gas source, that is, the inlet of the two-stage screw compressor 2 can additionally introduce a gas source, which increases the expandability of the whole system.
The two-stage screw compressor air volume adjusting method provided by the invention is described below, and the two-stage screw compressor air volume adjusting method described below and the two-stage screw compressor air volume adjusting device described above can be referred to correspondingly.
Referring to fig. 2, fig. 2 is a schematic flow chart of a method for adjusting the amount of gas in a two-stage screw compressor according to an embodiment of the present invention. An adjusting method based on the air quantity adjusting device of the two-stage screw compressor comprises the following steps:
and step 210, comparing the first feedback opening degree and the second feedback opening degree of the first-stage backflow regulating valve and the second-stage backflow regulating valve with the corresponding maximum opening degree and minimum opening degree respectively to determine whether the frequency converter needs to be controlled to increase the rotating speed or reduce the rotating speed.
And step 220, if the PZT1 is greater than the PZT1max and the PZT2 is greater than the PZT2max, controlling the frequency converter to reduce the rotating speed at a first preset speed.
And step 230, if the PZT1 is less than the PZT1min and the PZT2 is less than the PZT2min, controlling the frequency converter to increase the rotating speed at a second preset speed.
In a step 240, the process is executed,
and if the PZT is 1min < PZT1< PZT1max or the PZT is 2min < PZT2< PZT2max, controlling the frequency converter to keep the current rotating speed.
The PZT1 represents a first feedback opening degree of the primary backflow regulating valve, the PZT2 represents a second feedback opening degree of the secondary backflow regulating valve, the PZT1max represents a maximum opening degree of the primary backflow regulating valve, the PZT1min represents a minimum opening degree of the primary backflow regulating valve, the PZT2max represents a maximum opening degree of the secondary backflow regulating valve, and the PZT2min represents a minimum opening degree of the secondary backflow regulating valve.
And 250, comparing the first feedback opening degree of the primary reflux adjusting valve with the first given opening degree of the primary reflux adjusting valve.
And step 260, if the difference value of the two is greater than a first preset value, prompting that the primary reflux adjusting valve breaks down, and setting the primary reflux adjusting valve and the frequency converter to be in a manual state.
And 270, comparing the second feedback opening degree of the secondary backflow regulating valve with a second given opening degree of the secondary backflow regulating valve.
And step 280, if the difference value between the two values is greater than a second preset value, prompting that the secondary backflow regulating valve fails, and setting the secondary backflow regulating valve and the frequency converter to be in a manual state.
It should be noted that, the two-stage screw compressor air volume adjusting device provided in the embodiment of the present invention can achieve the functions achieved by the above device embodiment and achieve the same technical effects, and detailed descriptions of the same parts and beneficial effects as those of the device embodiment in this embodiment are omitted here.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. The utility model provides a two-stage screw compressor tolerance adjusting device, includes actuating mechanism, one-level, second grade screw compressor, through the actuating mechanism drive one-level, second grade screw compressor carry out gas compression's inverter motor and be used for adjusting the converter of inverter motor rotational speed, its characterized in that, adjusting device still includes:
the first-stage backflow regulating valve is arranged between the inlet and the outlet of the first-stage screw compressor and is used for regulating the compressed air quantity of the first-stage screw compressor;
the secondary backflow regulating valve is arranged between an inlet and an outlet of the secondary screw compressor and is used for regulating the air quantity compressed by the secondary screw compressor;
the first controller is connected with the primary backflow regulating valve and used for calculating a first given opening degree of the primary backflow regulating valve according to the measured air inlet pressure value of the primary screw compressor and a first preset value and controlling the valve to be opened to a first feedback opening degree;
the second controller is connected with the secondary backflow regulating valve and used for calculating according to the measured air inlet pressure value of the secondary screw compressor and a second preset set value to obtain a second given opening degree of the secondary backflow regulating valve and controlling the valve to be opened to a second feedback opening degree;
and the input end of the third controller is respectively connected with the first controller and the second controller, the output end of the third controller is connected with the frequency converter, and the third controller is used for comparing the first feedback opening degree and the second feedback opening degree of the primary backflow regulating valve and the secondary backflow regulating valve with the corresponding maximum opening degree and minimum opening degree respectively so as to determine whether the frequency converter needs to be controlled to increase the rotating speed or reduce the rotating speed.
2. The two-stage screw compressor air volume adjustment device of claim 1, wherein the third controller is further configured to:
if the PZT1 is larger than the PZT1max and the PZT2 is larger than the PZT2max, controlling the frequency converter to reduce the rotating speed at a first preset speed;
if the PZT1 is less than the PZT1min and the PZT2 is less than the PZT2min, controlling the frequency converter to increase the rotating speed at a second preset speed;
if the PZT is 1min < PZT1< PZT1max or the PZT is 2min < PZT2< PZT2max, controlling the frequency converter to keep the current rotating speed;
the method comprises the steps that PZT1 represents a first feedback opening degree of a primary return regulating valve, PZT2 represents a second feedback opening degree of a secondary return regulating valve, PZT1max represents a maximum opening degree of the primary return regulating valve, PZT1min represents a minimum opening degree of the primary return regulating valve, PZT2max represents a maximum opening degree of the secondary return regulating valve, and PZT2min represents a minimum opening degree of the secondary return regulating valve.
3. The two-stage screw compressor air quantity adjusting device according to claim 1, wherein the third controller is further configured to:
comparing the first feedback opening degree of the primary reflux regulating valve with the first given opening degree of the primary reflux regulating valve;
if the difference value between the first-stage backflow regulating valve and the frequency converter is larger than a first preset value, prompting that the first-stage backflow regulating valve breaks down, and setting the first-stage backflow regulating valve and the frequency converter to be in a manual state;
comparing a second feedback opening degree of the secondary reflux regulating valve with a second given opening degree of the secondary reflux regulating valve;
and if the difference value between the two is greater than a second preset value, prompting that the secondary backflow regulating valve fails, and setting the secondary backflow regulating valve and the frequency converter to be in a manual state.
4. The air quantity adjusting device of the two-stage screw compressor according to claim 1, wherein the one-stage backflow adjusting valve is a pneumatic adjusting valve comprising a first valve opening degree feedback device for feeding back the degree of opening of the valve; the second-stage backflow regulating valve is a pneumatic regulating valve and comprises a second valve opening degree feedback device for feeding back the valve opening degree.
5. The air quantity adjusting device of two-stage screw compressor according to claim 4, further comprising a first pressure detecting device and a second pressure detecting device, wherein the first pressure detecting device is used for measuring the air inlet pressure of the one-stage screw compressor, and the second pressure detecting device is used for measuring the air inlet pressure of the two-stage screw compressor.
6. The air quantity adjusting device of the two-stage screw compressor according to claim 1, wherein the transmission mechanism is a gear box, an input shaft, a first output shaft and a second output shaft are arranged inside the gear box, the variable frequency motor is connected with the input shaft and drives the input shaft to rotate, the first output shaft is connected to the one-stage screw compressor, and the second output shaft is connected to the two-stage screw compressor.
7. The two-stage screw compressor air volume adjusting device of claim 1, wherein the first controller, the second controller, and the third controller are all programmable logic controllers.
8. The air quantity adjusting device of the two-stage screw compressor as claimed in claim 1, wherein the inlet of the two-stage screw compressor is also used for connecting another air source.
9. An adjusting method of a gas amount adjusting device of a two-stage screw compressor based on claim 1, characterized by comprising the following steps:
comparing the first feedback opening degree and the second feedback opening degree of the first-stage backflow regulating valve and the second-stage backflow regulating valve with the corresponding maximum opening degree and minimum opening degree respectively to determine whether the frequency converter needs to be controlled to increase the rotating speed or decrease the rotating speed;
if the PZT1 is more than the PZT1max and the PZT2 is more than the PZT2max, controlling the frequency converter to reduce the rotating speed at a first preset speed;
if the PZT1 is less than the PZT1min and the PZT2 is less than the PZT2min, controlling the frequency converter to increase the rotating speed at a second preset speed;
if the PZT1min is less than the PZT1< PZT1max or the PZT2min is less than the PZT2< PZT2max, controlling the frequency converter to keep the current rotating speed;
the PZT1 represents a first feedback opening degree of the primary backflow regulating valve, the PZT2 represents a second feedback opening degree of the secondary backflow regulating valve, the PZT1max represents a maximum opening degree of the primary backflow regulating valve, the PZT1min represents a minimum opening degree of the primary backflow regulating valve, the PZT2max represents a maximum opening degree of the secondary backflow regulating valve, and the PZT2min represents a minimum opening degree of the secondary backflow regulating valve.
10. The two-stage screw compressor air flow adjusting method according to claim 9, further comprising:
comparing the first feedback opening degree of the primary backflow regulating valve with the first given opening degree of the primary backflow regulating valve;
if the difference value between the first preset value and the second preset value is larger than a first preset value, the first-stage backflow regulating valve is prompted to break down, and the first-stage backflow regulating valve and the frequency converter are set to be in a manual state;
comparing a second feedback opening degree of the secondary backflow regulating valve with a second given opening degree of the secondary backflow regulating valve;
and if the difference value of the two is greater than a second preset value, prompting that the secondary backflow regulating valve breaks down, and setting the secondary backflow regulating valve and the frequency converter to be in a manual state.
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| CN202211135866.4A CN115467830A (en) | 2022-09-19 | 2022-09-19 | Gas quantity adjusting device and method for two-stage screw compressor |
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| CN202211135866.4A CN115467830A (en) | 2022-09-19 | 2022-09-19 | Gas quantity adjusting device and method for two-stage screw compressor |
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007016614A (en) * | 2005-07-05 | 2007-01-25 | Kobe Steel Ltd | Screw compressor |
| JP2009097384A (en) * | 2007-10-15 | 2009-05-07 | Denyo Co Ltd | Engine-driven compressor |
| CN102927011A (en) * | 2011-08-12 | 2013-02-13 | 株式会社神户制钢所 | Compression apparatus |
| CN103982408A (en) * | 2014-04-09 | 2014-08-13 | 上海好米工业技术有限公司 | Multistage compressor section-by-section pressure control device based on PLC (programmable logic controller) |
| CN104747453A (en) * | 2015-02-07 | 2015-07-01 | 宁波鲍斯能源装备股份有限公司 | Two-stage screw compressor discharge pressure stabilizing device and two-stage screw compressor discharge pressure stabilizing method |
| CN105201807A (en) * | 2015-10-21 | 2015-12-30 | 蓝星（北京）技术中心有限公司 | Compressor operation control method and device based on pressure difference and flow control |
| CN205205089U (en) * | 2015-11-17 | 2016-05-04 | 宁波鲍斯能源装备股份有限公司 | High concentration coal bed gas system CNG device |
| CN205533159U (en) * | 2016-01-22 | 2016-08-31 | 中化重庆涪陵化工有限公司 | Energy -conserving synthetic ammonia natural gas compression system |
| CN110043467A (en) * | 2019-05-31 | 2019-07-23 | 上海齐耀螺杆机械有限公司 | Two-stage series connection compressor cycle reflux control system |
| CN112065701A (en) * | 2020-09-14 | 2020-12-11 | 中石化石油机械股份有限公司三机分公司 | Method for simultaneously controlling air intake and exhaust pressures of compressor |
-
2022
- 2022-09-19 CN CN202211135866.4A patent/CN115467830A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007016614A (en) * | 2005-07-05 | 2007-01-25 | Kobe Steel Ltd | Screw compressor |
| JP2009097384A (en) * | 2007-10-15 | 2009-05-07 | Denyo Co Ltd | Engine-driven compressor |
| CN102927011A (en) * | 2011-08-12 | 2013-02-13 | 株式会社神户制钢所 | Compression apparatus |
| CN103982408A (en) * | 2014-04-09 | 2014-08-13 | 上海好米工业技术有限公司 | Multistage compressor section-by-section pressure control device based on PLC (programmable logic controller) |
| CN104747453A (en) * | 2015-02-07 | 2015-07-01 | 宁波鲍斯能源装备股份有限公司 | Two-stage screw compressor discharge pressure stabilizing device and two-stage screw compressor discharge pressure stabilizing method |
| CN105201807A (en) * | 2015-10-21 | 2015-12-30 | 蓝星（北京）技术中心有限公司 | Compressor operation control method and device based on pressure difference and flow control |
| CN205205089U (en) * | 2015-11-17 | 2016-05-04 | 宁波鲍斯能源装备股份有限公司 | High concentration coal bed gas system CNG device |
| CN205533159U (en) * | 2016-01-22 | 2016-08-31 | 中化重庆涪陵化工有限公司 | Energy -conserving synthetic ammonia natural gas compression system |
| CN110043467A (en) * | 2019-05-31 | 2019-07-23 | 上海齐耀螺杆机械有限公司 | Two-stage series connection compressor cycle reflux control system |
| CN112065701A (en) * | 2020-09-14 | 2020-12-11 | 中石化石油机械股份有限公司三机分公司 | Method for simultaneously controlling air intake and exhaust pressures of compressor |
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