CN115435230B - Method for controlling viscosity of lubricating oil of centrifugal compressor - Google Patents
Method for controlling viscosity of lubricating oil of centrifugal compressor Download PDFInfo
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- CN115435230B CN115435230B CN202211072595.2A CN202211072595A CN115435230B CN 115435230 B CN115435230 B CN 115435230B CN 202211072595 A CN202211072595 A CN 202211072595A CN 115435230 B CN115435230 B CN 115435230B
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- 239000010687 lubricating oil Substances 0.000 title claims abstract description 138
- 238000000034 method Methods 0.000 title claims abstract description 46
- 239000003921 oil Substances 0.000 claims abstract description 324
- 239000003507 refrigerant Substances 0.000 claims abstract description 61
- 238000004891 communication Methods 0.000 claims abstract description 5
- 230000003247 decreasing effect Effects 0.000 claims abstract description 5
- 239000012530 fluid Substances 0.000 claims abstract description 5
- 239000000314 lubricant Substances 0.000 claims description 26
- 238000001816 cooling Methods 0.000 claims description 18
- 238000010438 heat treatment Methods 0.000 claims description 12
- 239000000203 mixture Substances 0.000 claims description 4
- 238000005461 lubrication Methods 0.000 description 16
- 239000007788 liquid Substances 0.000 description 9
- 238000010586 diagram Methods 0.000 description 7
- 230000008859 change Effects 0.000 description 5
- 230000008569 process Effects 0.000 description 4
- 238000004378 air conditioning Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- LVGUZGTVOIAKKC-UHFFFAOYSA-N 1,1,1,2-tetrafluoroethane Chemical compound FCC(F)(F)F LVGUZGTVOIAKKC-UHFFFAOYSA-N 0.000 description 1
- 230000003044 adaptive effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16N—LUBRICATING
- F16N39/00—Arrangements for conditioning of lubricants in the lubricating system
- F16N39/04—Arrangements for conditioning of lubricants in the lubricating system by heating
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16N—LUBRICATING
- F16N29/00—Special means in lubricating arrangements or systems providing for the indication or detection of undesired conditions; Use of devices responsive to conditions in lubricating arrangements or systems
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16N—LUBRICATING
- F16N39/00—Arrangements for conditioning of lubricants in the lubricating system
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Compressor (AREA)
Abstract
The application provides a control method for viscosity of lubricating oil of a centrifugal compressor. The control method comprises the following steps performed during operation of the centrifugal compressor: (1) -obtaining a real-time solubility D1 of the refrigerant in the oil sump (102) in the lubricating oil, said oil sump (102) being in fluid communication with said centrifugal compressor (101); and (2) comparing the real-time solubility D1 with a target solubility threshold D. If the comparison result is that the real-time solubility D1 is greater than or equal to the target solubility threshold D, an operation of decreasing the real-time solubility D1 is performed until the real-time solubility D1 is less than the target solubility threshold D. If the comparison result shows that the real-time solubility D1 is smaller than the target solubility threshold D, an operation of controlling the viscosity of the lubricating oil in real time is performed based on the real-time solubility D1.
Description
Technical Field
The invention relates to a control method for the viscosity of lubricating oil of a centrifugal compressor. In particular, the method of the present invention relates to controlling the viscosity of a lubricant based on the real-time solubility of a refrigerant in the lubricant during operation of a centrifugal compressor.
Background
Centrifugal compressors used in air conditioning systems and the like use lubricating oils to reduce friction and wear and to extend the fatigue life of the centrifugal compressors. When the lubricating oil cannot improve enough lubrication, the centrifugal compressor can be blocked. Thus, it is desirable that the lubricating oil provide reliable lubrication to ensure proper operation of the centrifugal compressor.
Disclosure of Invention
The application provides a control method for viscosity of lubricating oil of a centrifugal compressor. The control method considers the working condition change of a system using a centrifugal compressor, sets a variable target oil supply temperature based on the working condition change, and enables the real-time oil supply viscosity to be always equal to the target oil supply viscosity or enables the real-time bearing oil viscosity to be always equal to the target bearing oil viscosity by controlling the real-time oil supply temperature to be always equal to the target oil supply temperature. Therefore, the control method of the application enables the viscosity control of the lubricating oil of the centrifugal compressor to be more accurate.
According to one aspect of the present application, a method of controlling the viscosity of a lubricant for a centrifugal compressor is provided. The control method comprises the following steps performed during operation of the centrifugal compressor:
(1) Obtaining a real-time solubility D1 of refrigerant in a sump in a lubricating oil, the sump in fluid communication with the centrifugal compressor; and
(2) Comparing the real-time solubility D1 with a target solubility threshold D, and based on the result of the comparison, performing the following operations:
(2.1) when the real-time solubility D1 is greater than or equal to the target solubility threshold D, performing an operation of decreasing the real-time solubility D1 until the real-time solubility D1 is less than the target solubility threshold D;
or (b)
(2.2) when the real-time solubility D1 is smaller than the target solubility threshold D, performing an operation of controlling the viscosity of the lubricating oil in real time based on the real-time solubility D1.
In the control method as described above, the operation (2.2) includes: according to the real-time solubility D1 and the target oil supply viscosity V of the lubricating oil when being supplied to the centrifugal compressor Feed device Calculating a target oil supply temperature T of the lubricating oil when the lubricating oil is supplied to the centrifugal compressor Feed device 。
In the control method as described above, the operation (2.2) further includes the step of controlling the real-time oil supply viscosity V1 of the lubricating oil when supplied to the centrifugal compressor so that the real-time oil supply viscosity V1 is equal to the target oil supply viscosity V Feed device ：
Detecting a real-time oil supply temperature T2 of the lubricating oil when the lubricating oil is supplied to the centrifugal compressor; and
comparing the real-time oil supply temperature T2 with the target oil supply temperature T Feed device And based on the result of the comparison, performing the following operations:
when the real-time oil supply temperature T2 is greater than the target oil supply temperature T Feed device Reducing the real-time oil supply temperature T2 until the real-time oil supply temperature T2 is equal to the target oil supply temperature T Feed device ；
(ii) when the real-time oil supply temperature T2 is less than the target oil supply temperature T Feed device Increasing the real-time oil supply temperature T2 until the real-time oil supply temperature T2 is equal to the target oil supply temperature T Feed device The method comprises the steps of carrying out a first treatment on the surface of the Or (b)
(iii) when the real-time fueling temperature, T2, is equal to the target fueling temperature, T Feed device And calculating the real-time oil supply viscosity V1 of the lubricating oil when the lubricating oil is supplied to the centrifugal compressor according to the real-time oil supply temperature T2 and the real-time solubility D1, and outputting the real-time oil supply viscosity V1.
In the control method as described above, the operation (2.2) further includes: controlling a real-time bearing oil viscosity V2 of the lubricating oil when entering into a bearing gap of the centrifugal compressor by controlling a real-time oil supply temperature T2 of the lubricating oil when supplied to the centrifugal compressor such that the real-time bearing oil viscosity V2 is equal to a target bearing oil viscosity V of the lubricating oil when entering into the bearing gap of the centrifugal compressor Shaft 。
In the control method as described above, the operation of controlling the real-time bearing oil viscosity V2 of the lubricating oil as it enters the bearing gap of the centrifugal compressor includes the steps of:
comparing the real-time oil supply temperature T2 with the target oil supply temperature T Feed device And based on the result of the comparison, performing the following operations:
(i) When the real-time oil supply temperature T2 is greater than the target oil supply temperature T Feed device Reducing the real-time oil supply temperature T2 until the real-time oil supply temperature T2 is equal to the target oil supply temperature T Feed device ；
(ii) When the real-time oil supply temperature T2 is smallAt the target oil supply temperature T Feed device Increasing the real-time oil supply temperature T2 until the real-time oil supply temperature T2 is equal to the target oil supply temperature T Feed device The method comprises the steps of carrying out a first treatment on the surface of the Or (b)
(iii) When the real-time oil supply temperature T2 is equal to the target oil supply temperature T Feed device The following operations are performed:
acquiring a real-time bearing oil temperature T3 of the lubricating oil when the lubricating oil enters the bearing gap of the centrifugal compressor;
calculating a real-time bearing oil viscosity V2 of the lubricating oil when entering the bearing gap of the centrifugal compressor according to the real-time bearing oil temperature T3 and the real-time solubility D1; and
comparing the real-time bearing oil viscosity V2 with the target bearing oil viscosity V Shaft And based on the comparison result, performing the following operations:
(iv) when the real-time bearing oil viscosity V2 is greater than the target bearing oil viscosity V Shaft Reducing the target oil supply viscosity V Feed device And returns to the calculation of the target oil supply temperature T Feed device Is carried out by the steps of (a);
(V) when the real-time bearing oil viscosity V2 is less than the target bearing oil viscosity V Shaft Increasing the target oil supply viscosity V Feed device And returns to the calculation of the target oil supply temperature T Feed device Is carried out by the steps of (a); or (b)
(vi) when the real-time bearing oil viscosity V2 is equal to the target bearing oil viscosity V Shaft And outputting the real-time bearing oil viscosity V2.
In the control method as described above, the step (1) is performed by:
detecting a real-time oil sump temperature T1 and a real-time oil sump pressure P1 of the oil sump by a first temperature sensor and a pressure sensor provided on the oil sump; and
the real-time solubility D1 of the refrigerant in the oil sump in the lubricating oil is calculated from the real-time oil sump temperature T1 and the real-time oil sump pressure P1.
In the control method as described above, the step (2.1) is performed by heating the mixture of the lubricating oil and the refrigerant in the oil tank by a heating device so that the refrigerant is gasified out of the oil tank.
In the control method as described above, the real-time oil supply temperature T2 is detected by a second temperature sensor provided on the line between the lubricating oil cooling device and the centrifugal compressor.
In the control method as described above, the real-time oil supply temperature T2 is lowered by increasing the flow rate of the refrigerant supplied to the lubricating oil cooling device, and the real-time oil supply temperature T2 is raised by decreasing the flow rate of the refrigerant supplied to the lubricating oil cooling device.
In the control method as described above, the real-time bearing oil temperature T3 of the lubricating oil at the time of entering into the bearing gap of the centrifugal compressor is obtained by performing the following operations: and calculating the real-time bearing oil temperature T3 according to the real-time oil supply temperature T2, the real-time oil flow Q of the lubricating oil supplied to the centrifugal compressor and the real-time friction gear work FHP of the centrifugal compressor.
According to another aspect of the present application, there is provided a centrifugal compressor that is lubricated with a lubricating oil and whose viscosity is controlled using a control method according to the present application.
Drawings
FIG. 1 is a schematic block diagram of a centrifugal compressor lubrication oil circulation system.
FIG. 2 shows a control block diagram of the centrifugal compressor lubrication oil circulation system shown in FIG. 1.
Fig. 3 shows a flow chart for controlling the viscosity of a lubricant for a centrifugal compressor according to the present application.
Fig. 4 is a specific step of one embodiment of fig. 3 to obtain real-time solubility of the refrigerant.
FIG. 5 is a specific step of one embodiment of FIG. 3 for controlling the viscosity of a lubricating oil.
FIG. 6 is a specific step of another embodiment of FIG. 3 for controlling the viscosity of a lubricating oil.
Fig. 7 is a graph showing the relationship between the temperature, pressure and concentration of lubricating oil.
Fig. 8 is a graph showing a relationship among temperature, viscosity, and concentration of lubricating oil.
Fig. 9 is a block diagram illustrating the controller 110 of fig. 2.
Detailed Description
Various embodiments of the present application are described below with reference to the accompanying drawings, which form a part hereof. It should be understood that the same or similar reference numerals are used throughout this application to refer to the same parts where possible.
The viscosity of the centrifugal compressor lubricant affects the reliability of the lubrication effect of the lubricant. If the viscosity of the lubricant is too small, the fluidity of the lubricant is too high, resulting in insufficient thickness of the oil film formed between the bearing gaps of the centrifugal compressor. If the viscosity of the lubricating oil is too high, the friction force of the bearing motion is too high, so that heat between bearing gaps is not easy to take away. The present application controls the viscosity of the lubricating oil so that the lubricating oil can form an oil film of a suitable thickness in the bearing gap of the centrifugal compressor so that the lubricating oil can provide a reliable lubricating effect. The inventors of the present application have found that the viscosity of the lubricating oil is related to the solubility of the refrigerant in the lubricating oil, which varies with operating conditions. Thus, the present application captures and controls the real-time solubility of the refrigerant so that it does not exceed the refrigerant solubility threshold and controls the lubricant viscosity based on the real-time solubility of the refrigerant.
Fig. 1 is a schematic block diagram of a centrifugal compressor lubrication oil circulation system 100, the centrifugal compressor lubrication oil circulation system 100 employing a method of improving lubrication oil reliability according to the present application. As shown in fig. 1, the centrifugal compressor lubrication oil circulation system 100 includes a centrifugal compressor 101. The centrifugal compressor 101 and the sump 102 are in fluid communication via a line 111 such that lubricating oil in the centrifugal compressor 101 can flow into the sump 102. The lubricating oil enters the oil sump 102 and mixes with refrigerant from a system (e.g., an air conditioning system) using the centrifugal compressor 101. A heating device 103 is provided in the oil sump 102 for heating the mixture of lubricating oil and refrigerant in the oil sump 102. Fig. 1 also shows another line 112 connecting the centrifugal compressor 101 and the sump 102, when the mixture of lubricating oil and refrigerant in the sump 102 is heated, the refrigerant is vaporized and the gaseous refrigerant returns to the suction side of the centrifugal compressor 101 via line 112. A temperature sensor 104 and a pressure sensor 105 are provided inside or outside the oil tank 102 for detecting a real-time oil tank temperature T1 and a real-time oil tank pressure P1 in the oil tank. The oil sump 102 and the lubricating oil cooling device 107 are in fluid communication such that the lubricating oil in the oil sump enters the lubricating oil cooling device 107. The lube oil cooling unit 107 receives liquid refrigerant which exchanges heat with lube oil entering the lube oil cooling unit 107 to cool the lube oil, and the liquid refrigerant gasifies into gaseous refrigerant leaving the lube oil cooling unit 107 after the heat exchange. A valve 108 is provided in a line for feeding the liquid refrigerant to the lubricating oil cooling device 107, and the flow rate of the liquid refrigerant fed into the lubricating oil cooling device 107 can be adjusted by adjusting the opening degree of the valve 108. The lubricating oil cooled in the lubricating oil cooling device 107 returns to the centrifugal compressor 101 through a line 113. As shown in fig. 1, a temperature sensor 106 is provided in the pipe 113 for detecting the real-time oil supply temperature T2 when the lubricating oil is supplied to the centrifugal compressor 101.
FIG. 2 illustrates a control module block diagram 200 of the centrifugal compressor lubrication oil circulation system 100 shown in FIG. 1. As shown in fig. 2, the temperature sensor 104, the temperature sensor 106 and the pressure sensor 105 are communicatively connected to the controller 110 for transmitting the detected real-time oil sump temperature T1, real-time oil supply temperature T2 and real-time oil sump pressure P1 to the controller 110, and the controller 110 calculates a lubricant parameter based on the received real-time oil sump temperature T1, real-time oil supply temperature T2 and real-time oil sump pressure P1 and controls the heating device 103 to start or shut off the heating of the oil or control the opening of the valve 108 to adjust the lubricant parameter or controls the display 109 to display the real-time parameter of the lubricant.
Fig. 3 illustrates a flow chart 300 of a method of controlling the viscosity of a centrifugal compressor lubricant according to the present application. The method according to the present application obtains and controls the real-time solubility of the refrigerant in the lubricating oil such that the real-time solubility is always less than the target solubility threshold and controls the viscosity of the lubricating oil based on the real-time solubility of the refrigerant in the lubricating oil.
In step 301, the flow starts.
At step 302, the controller 110 obtains the real-time solubility D1 of the refrigerant in the lubricating oil in the oil sump 102. After the operation of step 302 is completed, step 303 is performed.
In step 303, the controller 110 compares the real-time solubility D1 of the refrigerant in the lubricating oil with the target solubility threshold D. If the real-time solubility D1 is greater than or equal to the target solubility threshold D, then step 304 is performed. If the real-time solubility D1 is less than the target solubility threshold D, then step 305 is performed.
At step 304, the controller 110 reduces the real-time solubility D1 of the refrigerant in the lubricating oil. After executing step 304, the process returns to step 302 to re-execute the steps of flow 300. In one embodiment, the real-time solubility D1 of the refrigerant in the lubricating oil is reduced by turning on the heating device 103 in the sump 102 such that the refrigerant in the sump 102 is vaporized out of the sump 102 and returned to the centrifugal compressor 101.
In step 305, the controller 110 performs an operation of controlling the viscosity of the lubricating oil. As will be described in detail below, this step 305 is performed based on the real-time solubility D1 of the refrigerant in the lubricating oil.
At step 306, the flow ends.
Fig. 4 is a specific step of one embodiment of step 302 in fig. 3.
In step 401, the temperature sensor 104 detects a real-time sump temperature T1, the pressure sensor 105 detects a real-time sump pressure P1, and transmits the detected real-time sump temperature T1 and real-time sump pressure P1 to the controller 110. After the operation of step 401 is completed, step 402 is performed.
In step 402, the controller 110 calculates a real-time solubility D1 of the refrigerant in the oil sump in the lubricating oil based on the real-time sump temperature T1 and the real-time sump pressure P1. Thus, the controller 110 obtains the real-time solubility D1 of the refrigerant in the oil sump 102 in the lubricating oil.
Fig. 5 is a specific step of one embodiment of step 305 in fig. 3. In this embodiment, the controller 110 controls the lubrication oil to be supplied to the centrifugal compressor 101 such that the real-time oil supply viscosity V1 is equal to the target oil supply viscosity V when the lubricating oil is supplied to the centrifugal compressor 101 Feed device . This is achieved by controlling such that the real-time oil supply temperature T2 when the lubricating oil is supplied to the centrifugal compressor 101 is equal to the target oil supply temperature T when the lubricating oil is supplied to the centrifugal compressor 101 Feed device To realize the method.
In step 501, the controller 110 determines the target oil supply viscosity V based on the real-time solubility D1 Feed device Calculating a target oil supply temperature T Feed device . After the operation of step 501 is completed, step 502 is performed.
In step 502, the temperature sensor 106 detects the real-time oil supply temperature T2, and transmits the detected real-time oil supply temperature T2 to the controller 110. After the operation of step 502 is completed, step 503 is performed.
In step 503, the controller 110 calculates the detected real-time oil supply temperature T2 and the calculated target oil supply temperature T Feed device A comparison is made. If the real-time oil supply temperature T2 is equal to the target oil supply temperature T Feed device Step 504 is performed. If the real-time oil supply temperature T2 is not equal to the target oil supply temperature T Feed device Step 507 is executed.
In step 504, the controller 110 calculates a real-time oil supply viscosity V1 based on the real-time oil supply temperature T2 and the real-time solubility D1. After the operation of step 504 is completed, the operation of step 505 is performed.
In step 505, the controller 110 instructs the display 109 to output the real-time oil supply viscosity V1.
In step 507, the controller 110 compares whether the real-time oil supply temperature T2 is greater than the target oil supply temperature T Feed device . If the real-time oil supply temperature T2 is greater than the target oil supply temperature T Feed device Step 508 is performed. If the real-time oil supply temperature T2 is smaller than the target oil supply temperature T Feed device Step 509 is performed.
In step 508, control decreases the real-time fueling temperature, T2. In one embodiment, the controller 110 controls the valve 108 to be opened to increase the flow of liquid refrigerant into the lube oil cooling unit 107 to reduce the real-time lube oil temperature T2.
In step 509, control increases the real-time fueling temperature, T2. In one embodiment, the controller 110 controls the valve 108 to be closed, reducing the flow of liquid refrigerant into the lube oil cooling unit 107 to increase the real-time lube oil temperature T2.
After step 508 or 509, returning to step 502, performing the steps 502 and thereafter again until the real-time oil supply temperature T2 is equal to the target oil supply temperature T Feed device So that the real-time oil supply viscosity V1 is equal to the target oil supply viscosity V Feed device 。
Fig. 6 is a specific step of another embodiment of step 305 in fig. 3. In this embodiment, the controller 110 controls the real-time oil supply temperature T2 to control the real-time bearing oil viscosity V2 when the lubricating oil enters the bearing gap of the centrifugal compressor 101 so that the real-time bearing oil viscosity V2 is equal to the target bearing oil viscosity V axis when the lubricating oil enters the bearing gap of the centrifugal compressor 101.
In step 601, the controller 110 determines a target oil supply viscosity V according to the real-time solubility D1 Feed device Calculating a target oil supply temperature T Feed device . After the operation of step 601 is completed, step 602 is performed.
In step 602, the temperature sensor 106 detects the real-time oil supply temperature T2, and transmits the detected real-time oil supply temperature T2 to the controller 110. After the operation of step 602 is completed, step 603 is performed.
In step 603, the controller 110 calculates the detected real-time oil supply temperature T2 and the calculated target oil supply temperature T Feed device A comparison is made. If the real-time oil supply temperature T2 is not equal to the target oil supply temperature T Feed device Step 604 is performed. If the real-time oil supply temperature T2 is equal to the target oil supply temperature T Feed device Step 607 is performed.
In step 604, control compares whether the real-time fueling temperature, T2, is greater than the target fueling temperature, T Feed device . If the real-time oil supply temperature T2 is greater than the target oil supply temperature T Feed device Step 605 is performed. If the real-time oil supply temperature T2 is smaller than the target oil supply temperature T Feed device Step 606 is performed.
In step 605, control decreases the real-time oil supply temperature T2. In one embodiment, the controller 110 controls the valve 108 to be opened to increase the flow of liquid refrigerant into the lube oil cooling unit 107The real-time oil supply temperature T2 is reduced. After step 605, returning to step 602, the operations of step 602 and thereafter are performed again until the real-time oil supply temperature T2 is equal to the target oil supply temperature T Feed device 。
In step 606, control increases the real-time oil supply temperature T2. In one embodiment, the controller 110 controls the valve 108 to be closed, reducing the flow of liquid refrigerant into the lube oil cooling unit 107 to increase the real-time lube oil temperature T2. After step 606, returning to step 602, the operations of step 602 and thereafter are performed again until the real-time oil supply temperature T2 is equal to the target oil supply temperature T Feed device 。
In step 607, the controller 110 obtains the real-time bearing oil temperature T3. After the operation of step 607 is completed, step 608 is performed. In one embodiment, the controller 110 calculates the real-time bearing oil temperature T3 using the following formula:
FHP＝CQΔT
wherein FHP is real-time friction gear work of the centrifugal compressor 101, C is specific heat capacity of lubricating oil, Q is real-time oil supply amount of the lubricating oil supplied to the centrifugal compressor 101, and DeltaT is a temperature difference value that the real-time bearing oil temperature T3 is higher than the real-time oil supply temperature T2. In this formula, FHP can be found based on empirical values or tests on other systems. The FHP value for the centrifugal compressor 101 of the current system may be calculated by fitting the empirical value of FHP or test results on other systems to a formula and substituting the operating parameters of the current system into the fitted formula. Q can be derived from the frequency of the oil pump. T2 can be detected. C is supplied by the lubricating oil manufacturer. Thus, on the basis of the known FHP, C, Q and T2, the real-time bearing oil temperature T3 can be calculated using the above formula.
At step 608, the controller 110 calculates a real-time bearing oil viscosity V2 of the lubricating oil as it enters the bearing gap of the centrifugal compressor based on the real-time bearing oil temperature T3 and the real-time solubility D1. After the operation of step 608 is completed, step 609 is performed.
In step 609, the controller 110 compares the real-time bearing oil viscosity V2 and the target bearing oil viscosity V Shaft A comparison is made. If the real-time bearing oil viscosity V2 is equal to the target bearing oil viscosity V Shaft Executing steps ofStep 610. If the real-time bearing oil viscosity V2 is not equal to the target bearing oil viscosity V Shaft Step 612 is performed.
At step 610, the controller 110 instructs the display 109 to output the real-time bearing oil viscosity V2.
In step 612, the controller 110 compares whether the real-time bearing oil viscosity V2 is greater than the target bearing oil viscosity V Shaft . If the viscosity V2 of the real-time bearing oil is greater than the viscosity V of the target bearing oil Shaft The controller 110 performs step 613. If the viscosity V2 of the real-time bearing oil is smaller than the viscosity V of the target bearing oil Shaft The controller 110 executes step 614.
In step 613, control decreases the target oil supply viscosity V Feed device 。
In step 614, control increases the target oil supply viscosity V Feed device 。
After the operation of step 613 or 614, returning to step 601, the flow of step 305 shown in fig. 6 is performed again until the real-time bearing oil viscosity V2 is equal to the target bearing oil viscosity V Shaft 。
Fig. 7 is a graph showing the relationship between the temperature, pressure and concentration of lubricating oil. The map is fitted to a formula stored in the controller 110, and the controller 110 performs step 402 of fig. 4 according to the map, i.e., calculates the real-time solubility D1 of the refrigerant according to the real-time sump temperature T1 and the real-time sump pressure P1. For example, as shown in fig. 7, when the real-time oil sump temperature T1 is 30 ℃, the real-time oil sump pressure is 5bar, the concentration of the lubricating oil is 80%, and accordingly, the real-time solubility D1 of the refrigerant is 20%.
Fig. 8 shows a graph of the relationship between the temperature, viscosity and concentration of lubricating oil. The map is fitted to a formula stored in the controller 110, and the controller 110 performs the steps 504 of fig. 5 and steps 601 and 608 of fig. 6 according to the map, i.e., according to the real-time solubility D1 of the refrigerant and the target oil supply viscosity V Feed device Calculating a target oil supply temperature T The liquid is supplied to the device and the device is supplied to the device, and calculating the real-time bearing oil viscosity V2 according to the real-time solubility D1 of the refrigerant and the real-time bearing oil temperature T3. For example, as shown in FIG. 8, when the real-time concentration of the lubricating oil is 70% (i.e., the real-time solubility D1 of the refrigerant is 30%), the target oil supply viscosity V Feed device At 10cts, the target oil supply temperature T Feed device Should be set at 34 ℃. When the real-time concentration of the lubricating oil is 95% (i.e., the real-time solubility D1 of the refrigerant is 5%), the real-time bearing oil temperature T3 is 86 ℃, and the real-time bearing oil viscosity V2 is 10cts.
The charts shown in fig. 7 and 8 are available from lube manufacturers. Fig. 7 and 8 are diagrams showing lubricating oil corresponding to the refrigerant R-134 a. It should be understood that different lubricating oils may have different charts than those shown in fig. 7 and 8.
Fig. 9 is a block diagram illustrating the controller 110 in fig. 2, showing main components of the controller 110. The controller 110 is capable of storing and executing programs of the processes shown in fig. 3 to 6, and storing and calling parameters and formulas required for the processes shown in fig. 3 to 6.
As shown in fig. 9, the controller 110 includes a bus 901, a processor 902, a memory 903, an input interface 904, and an output interface 905. The processor 902, the memory 903, the input interface 904, and the output interface 905 are connected to the bus 901. The processor 902 may read out a program (or instructions) from the memory 903 and execute the program (or instructions) to process data; the processor 902 may also write data or programs (or instructions) into the memory 903. The memory 903 may store programs (instructions) or data. The processor 902 may control the memory 903, the input interface 904, and the output interface 905 by executing instructions in the memory 903. In this application, the memory 903 can store programs for executing the flows shown in fig. 3 to 6 and operation parameters and formulas required for executing the programs.
The input interface 904 is configured to receive the real-time sump temperature T1 from the temperature sensor 104, the real-time sump pressure P1 from the pressure sensor 105, and the real-time oil supply temperature T2 from the temperature sensor 106, and convert these data into signals recognizable to the processor 902 and store in the memory 903. The processor 902 is configured to calculate and control the real-time solubility D1 of the refrigerant to be smaller than the target solubility threshold D1 according to a program stored in the memory 903, and calculate and control the real-time oil supply viscosity V1 to be always equal to the target oil supply viscosity V Feed device Or calculating and controlling the real-time bearing oil viscosity V2 to always be equal to the target bearing oil viscosity V Shaft 。
The output interface 905 is configured to receive a control signal from the processor 902 and transmit the control signal to the heating device 103 to perform an operation of heating oil or turning off the heating of oil, or to the valve 108 to perform an operation of opening or closing the valve 108, or to the display 109 to perform an operation of outputting the real-time oil supply viscosity V1 or the real-time bearing oil viscosity V2.
As can be seen from the above description, the present application always equals the target oil supply temperature T by controlling the real-time oil supply temperature T2 Feed device To control the real-time oil supply viscosity V1 or the real-time bearing oil viscosity V2. One advantage of the present application is that the target oil supply temperature T is set as a function of operating conditions Feed device Enabling accurate control of the real-time oil supply viscosity V1 to always be equal to the target oil supply viscosity V Feed device Or accurately controlling the viscosity V2 of the real-time bearing oil to be always equal to the viscosity V of the target bearing oil Shaft 。
During the operation of the centrifugal compressor 101, the pressure P1 and the temperature T1 of the oil sump 102 are varied due to the different conditions of an air conditioning system or the like using the centrifugal compressor 101, which results in a variation in the solubility D1 of the refrigerant in the lubricating oil. When the solubility D1 of the refrigerant in the lubricating oil changes along with the working condition, the real-time oil supply viscosity V1 reaches the set target oil supply viscosity V Feed device The present application sets a target oil supply temperature T that varies with the real-time solubility D1 Feed device The real-time oil supply temperature T2 can be timely adjusted to a proper value under the condition of working condition change so as to obtain the target oil supply viscosity V Feed device Or target bearing oil viscosity V Shaft . Specifically, the present application detects and controls the real-time solubility D1 of the refrigerant such that the real-time solubility D1 is always smaller than the target solubility threshold D in consideration of the influence of the operating condition change on the solubility D1 of the refrigerant, and sets the target oil supply temperature T based on the real-time solubility D1 of the refrigerant Feed device And by controlling the real-time oil supply temperature T2 to be always equal to the target oil supply temperature T Feed device So that the real-time oil supply viscosity V1 is always equal to the target oil supply viscosity V Feed device Or to make the real-time bearing oil viscosity V2 always equal to the target bearing oil viscosity V Shaft . Since the present application sets the target supply based on the real-time solubility D1 of the refrigerantTemperature T of oil Feed device Target oil supply temperature T in the present application Feed device Is changed at any time according to working conditions, and is not a fixed value. Thus, the control of the real-time oil supply temperature T2 of the lubricating oil is adaptive to the working condition change. Correspondingly, the control of the real-time oil supply viscosity V1 or the real-time bearing oil viscosity V2 of the lubricating oil is more accurate, so that the real-time oil supply viscosity V1 can be always equal to the target oil supply viscosity V no matter how the working condition changes Feed device Or to enable the real-time bearing oil viscosity V2 to always be equal to the target bearing oil viscosity V Shaft 。
And the final purpose of controlling the viscosity of the lubricating oil is to form an oil film of a suitable thickness in the bearing gap of the centrifugal compressor to produce reliable lubrication. Thus, the real-time bearing oil viscosity V2 in the bearing gap of the centrifugal compressor is directly controlled to be equal to the target bearing oil viscosity V Shaft It is more advantageous to control the oil film thickness in the bearing gap. As described hereinabove, the present application also provides a method of directly controlling the real-time bearing oil viscosity V2 in the bearing gap of a centrifugal compressor such that the real-time bearing oil viscosity V2 is always equal to the target bearing oil viscosity V Shaft . The control real-time bearing oil viscosity V2 of the application is always equal to the target bearing oil viscosity V Shaft The method of (2) is advantageous in ensuring that the lubricating oil forms a suitable oil film thickness in the bearing gap of the centrifugal compressor, resulting in reliable lubrication.
In addition, as described hereinabove, the control method of the present application also achieves control of the real-time solubility D1 of the refrigerant in the lubricating oil while controlling the viscosity of the lubricating oil. Controlling the real-time solubility D1 of the refrigerant in the lubricating oil is also advantageous for producing reliable lubrication of the lubricating oil. This is because the solubility D1 of the refrigerant in the lubricating oil also affects the thickness of the oil film formed by the lubricating oil in the bearing gap of the centrifugal compressor. If the solubility of the refrigerant in the lubricating oil is too high, the amount of the lubricating oil is insufficient, and when the lubricating oil enters the centrifugal compressor bearing gap, the refrigerant is volatilized in contact with the high-temperature bearing, and the insufficient lubricating oil is difficult to form an oil film of sufficient thickness in the bearing gap, so that reliable lubrication cannot be provided. The present application controls the real-time solubility D1 of the refrigerant in the lubricating oil to be always less than the target solubility threshold D, which makes it possible to ensure that a sufficient amount of lubricating oil enters the bearing gap of the centrifugal compressor, thereby ensuring that the lubricating oil can form an oil film of sufficient thickness in the bearing gap to produce reliable lubrication.
While the present disclosure has been described in conjunction with the examples of embodiments outlined above, various alternatives, modifications, variations, improvements, and/or substantial equivalents, whether known or that are or may be presently or later be envisioned, may be apparent to those of ordinary skill in the art. Further, the technical effects and/or technical problems described in the present specification are exemplary rather than limiting; the disclosure in this specification may be used to solve other technical problems and to have other technical effects and/or may solve other technical problems. Accordingly, the examples of embodiments of the disclosure as set forth above are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit or scope of the disclosure. Accordingly, the present disclosure is intended to embrace all known or earlier developed alternatives, modifications, variations, improvements and/or substantial equivalents.
Claims (10)
1. A method of controlling the viscosity of a lubricant in a centrifugal compressor, comprising the steps of, during operation of said centrifugal compressor:
(1) -obtaining a real-time solubility D1 of the refrigerant in the oil sump (102) in the lubricating oil, said oil sump (102) being in fluid communication with said centrifugal compressor (101); and
(2) Comparing the real-time solubility D1 with a target solubility threshold D, and based on the result of the comparison, performing the following operations:
(2.1) when the real-time solubility D1 is greater than or equal to the target solubility threshold D, performing an operation of decreasing the real-time solubility D1, and returning to step (1); or (b)
(2.2) when the real-time solubility D1 is smaller than the target solubility threshold D, performing an operation of controlling the viscosity of the lubricating oil in real time based on the real-time solubility D1,
wherein the operation (2.2) comprises:
according to the real-time solubility D1 and the target oil supply viscosity V of the lubricating oil when being supplied to the centrifugal compressor (101) Feed device Calculating a target oil supply temperature T of the lubricating oil when the lubricating oil is supplied to the centrifugal compressor (101) Feed device 。
2. A control method of the lubricant viscosity of a centrifugal compressor according to claim 1, characterized in that the operation (2.2) further comprises the step of controlling the real-time lubricant viscosity V1 of the lubricant when supplied to the centrifugal compressor (101) such that the real-time lubricant viscosity V1 is equal to the target lubricant viscosity V Feed device ：
Detecting a real-time oil supply temperature T2 of the lubricating oil when supplied to the centrifugal compressor (101); and
comparing the real-time oil supply temperature T2 with the target oil supply temperature T Feed device And based on the result of the comparison, performing the following operations:
when the real-time oil supply temperature T2 is greater than the target oil supply temperature T Feed device Reducing the real-time oil supply temperature T2 until the real-time oil supply temperature T2 is equal to the target oil supply temperature T Feed device ；
(ii) when the real-time oil supply temperature T2 is less than the target oil supply temperature T Feed device The real-time oil supply temperature T2 is increased,
until the real-time oil supply temperature T2 is equal to the target oil supply temperature T Feed device The method comprises the steps of carrying out a first treatment on the surface of the Or (b)
(iii) when the real-time fueling temperature, T2, is equal to the target fueling temperature, T Feed device A real-time oil supply viscosity V1 of the lubricating oil when supplied to the centrifugal compressor (101) is calculated from the real-time oil supply temperature T2 and the real-time solubility D1, and the real-time oil supply viscosity V1 is outputted.
3. A method of controlling the viscosity of a lubricant for a centrifugal compressor according to claim 1, wherein said operation (2.2) further comprises:
by controllingThe real-time oil supply temperature T2 of the lubricating oil when being supplied to the centrifugal compressor (101) controls the real-time bearing oil viscosity V2 of the lubricating oil when entering the bearing gap of the centrifugal compressor (101) so that the real-time bearing oil viscosity V2 is equal to the target bearing oil viscosity V of the lubricating oil when entering the bearing gap of the centrifugal compressor (101) Shaft 。
4. A control method of the viscosity of a lubricant oil for a centrifugal compressor according to claim 3, characterized in that said operation of controlling the real-time bearing oil viscosity V2 of said lubricant oil upon entering the bearing gap of said centrifugal compressor (101) comprises the steps of:
comparing the real-time oil supply temperature T2 with the target oil supply temperature T Feed device And based on the result of the comparison, performing the following operations:
(i) When the real-time oil supply temperature T2 is greater than the target oil supply temperature T Feed device Reducing the real-time oil supply temperature T2,
until the real-time oil supply temperature T2 is equal to the target oil supply temperature T Feed device ；
(ii) When the real-time oil supply temperature T2 is smaller than the target oil supply temperature T Feed device The real-time oil supply temperature T2 is increased,
until the real-time oil supply temperature T2 is equal to the target oil supply temperature T Feed device The method comprises the steps of carrying out a first treatment on the surface of the Or (b)
(iii) When the real-time oil supply temperature T2 is equal to the target oil supply temperature T Feed device The following operations are performed:
acquiring a real-time bearing oil temperature T3 of the lubricating oil when entering the bearing gap of the centrifugal compressor (101);
calculating a real-time bearing oil viscosity V2 of the lubricating oil when entering the bearing gap of the centrifugal compressor (101) from the real-time bearing oil temperature T3 and the real-time solubility D1; and
comparing the real-time bearing oil viscosity V2 with the target bearing oil viscosity V Shaft And based on the comparison result, performing the following operations:
(iv) when said real timeThe bearing oil viscosity V2 is greater than the target bearing oil viscosity V Shaft Reducing the target oil supply viscosity V Feed device And returns to the calculation of the target oil supply temperature T Feed device Is carried out by the steps of (a);
(V) when the real-time bearing oil viscosity V2 is less than the target bearing oil viscosity V Shaft Increasing the target oil supply viscosity V Feed device And returns to the calculation of the target oil supply temperature T Feed device Is carried out by the steps of (a); or (b)
(vi) when the real-time bearing oil viscosity V2 is equal to the target bearing oil viscosity V Shaft And outputting the real-time bearing oil viscosity V2.
5. The method of controlling the viscosity of a lubricant for a centrifugal compressor according to claim 1, wherein said step (1) is performed by:
detecting a real-time tank temperature T1 and a real-time tank pressure P1 of the oil tank (102) by a first temperature sensor (104) and a pressure sensor (105) provided on the oil tank (102); and
the real-time solubility D1 of the refrigerant in the oil sump (102) in the lubricating oil is calculated from the real-time oil sump temperature T1 and the real-time oil sump pressure P1.
6. The method for controlling the viscosity of a lubricant for a centrifugal compressor according to claim 1,
-said step (2.1) is performed by heating a mixture of said lubricating oil and said refrigerant in said oil sump (102) by heating means (103) such that said refrigerant is gasified out of said oil sump (102).
7. A method for controlling the viscosity of a lubricant for a centrifugal compressor according to claim 2 or 3,
the real-time oil supply temperature T2 is detected by a second temperature sensor (106) provided on the line between the lubricating oil cooling device (107) and the centrifugal compressor (101).
8. The method for controlling the viscosity of a lubricant for a centrifugal compressor according to claim 7,
the real-time oil supply temperature T2 is reduced by increasing the flow rate of the refrigerant supplied to the lubricating oil cooling device (107), and the real-time oil supply temperature T2 is increased by decreasing the flow rate of the refrigerant supplied to the lubricating oil cooling device (107).
9. The control method of the viscosity of the lubricating oil of the centrifugal compressor according to claim 4, characterized by obtaining the real-time bearing oil temperature T3 of the lubricating oil when it enters the bearing gap of the centrifugal compressor (101) by performing the following operations:
-calculating said real-time bearing oil temperature T3 from said real-time oil supply temperature T2, a real-time oil flow Q of said lubricating oil supplied to said centrifugal compressor (101) and a real-time friction gear work FHP of said centrifugal compressor (101).
10. A centrifugal compressor which is lubricated with a lubricating oil, characterized in that,
use of a control method according to any of the preceding claims 1-9 for controlling the viscosity of the lubricating oil.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0763184A (en) * | 1993-08-25 | 1995-03-07 | Yamaha Motor Co Ltd | Lubrication control method for heat pump driving compressor and its device |
| JPH07103583A (en) * | 1993-09-30 | 1995-04-18 | Toshiba Corp | Air-conditioning equipment |
| JPH09170826A (en) * | 1995-12-21 | 1997-06-30 | Matsushita Electric Ind Co Ltd | Air conditioner |
| CN103827597A (en) * | 2011-09-30 | 2014-05-28 | 大金工业株式会社 | Refrigeration device |
| CN104380009A (en) * | 2012-05-09 | 2015-02-25 | 三菱电机株式会社 | Refrigerant compressor and heat pump device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006013636A1 (en) * | 2004-08-03 | 2006-02-09 | Mayekawa Mfg.Co.,Ltd. | Lubricant supply system and operating method of multisystem lubrication screw compressor |
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- 2022-09-02 CN CN202211072595.2A patent/CN115435230B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0763184A (en) * | 1993-08-25 | 1995-03-07 | Yamaha Motor Co Ltd | Lubrication control method for heat pump driving compressor and its device |
| JPH07103583A (en) * | 1993-09-30 | 1995-04-18 | Toshiba Corp | Air-conditioning equipment |
| JPH09170826A (en) * | 1995-12-21 | 1997-06-30 | Matsushita Electric Ind Co Ltd | Air conditioner |
| CN103827597A (en) * | 2011-09-30 | 2014-05-28 | 大金工业株式会社 | Refrigeration device |
| CN104380009A (en) * | 2012-05-09 | 2015-02-25 | 三菱电机株式会社 | Refrigerant compressor and heat pump device |
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