Method for estimating a mechanical overhaul interval for an open-type industrial compressor with reciprocating or direct flow

Abstract

Estimation of an actual overhaul interval for an open industrial compressor with alternating or direct flow, comprising: - the determination (1) of the evaporation pressure P0 and the condensation pressure Pk of the compressor in operation; - the determination (3) of the actual overhaul interval Ir by applying a start-up coefficient Fd and a correction coefficient Fc to a general overhaul interval Ig; the general overhaul interval Ig depending on said evaporation pressures P0 and condensation pressures Pk; the correction coefficient Fc being a function of the load of the compressor in operation; and the start-up coefficient Fd being a function of a predicted number of starts and total operating hours of the compressor over a predefined time interval; - the updating (4) of a future overhaul time as a function of the value of the actual overhaul interval Ir determined, and the date of the last overhaul.Figure for the abridged version: Fig 4.

Description

Title of the invention: Method for estimating a mechanical overhaul interval for an open-type industrial compressor with alternating or direct flow. Technical field

[0001] The invention relates to the field of open industrial compressors, both piston (reciprocating) and screw (direct flow). More specifically, the invention relates to the mechanical overhaul intervals of these compressors. State of the art

[0002] To ensure optimal operation of an open reciprocating or direct-flow compressor, regular inspection and maintenance of the mechanical components of these compressors must be carried out. These preventive maintenance operations help to ensure proper operation, extend the equipment's service life, and reduce unforeseen repair costs associated with corrective maintenance.

[0003] Maintenance operations are generally carried out after a certain number of compressor operating hours, and include, for example:

[0004] In the case of a "piston" compressor: - replacing the oil filter, - replacing the sealing gasket, - the replacement of the suction and discharge valves and springs, - the replacement of the segments, - the replacement of the connecting rod bearings, - etc.

[0005] In the case of a "screw" compressor: - replacing the oil filter, - replacing the sealing gasket, - the replacement of the thrust bearings, - the replacement of bearing housings or plain bearings, - etc.

[0006] In the case of a "single-screw" compressor: - replacing the oil filter, - replacing the sealing gasket, - the replacement of carbon components in satellites, - the replacement of the satellite thrust bearings, - etc.

[0007] In practice, each manufacturer defines the recommendations and maintenance instructions for the various compressor parts. The frequency of intervention generally varies depending on the parts to be inspected, and some manufacturers define a general hourly overhaul interval that serves as a basis for determining maintenance cycles.

[0008] The general overhaul interval depends on several parameters, such as type of compressors (piston, screw or single screw), the refrigerant used, specific operating conditions, etc.

[0009] For an open piston compressor, the manufacturer generally provides specific curves indicating, in particular, the maximum number of operating hours of the compressor between maintenance operations, depending on operating conditions. Such a curve is illustrated in [Fig. 1], giving the maximum number of operating hours of the compressor as a function of the condensing pressures PC and evaporating pressures PE for a type of refrigerant. Thus, according to the curve in [Fig. 1], the general recommended overhaul interval would be 12,600 hours for operation involving a condensing pressure PC of 10 bar and an evaporating pressure PE of 5 bar, and the general recommended overhaul interval would be 7,000 hours for operation involving a condensing pressure PC of 35 bar and an evaporating pressure PE of 20 bar.

[0010] For an open screw compressor, the manufacturer usually gives a simple fixed value for the general overhaul interval, for example 30000 hours.

[0011] Furthermore, for open piston compressors, since the rotational speed impacts the friction of the components, the manufacturer recommends applying a correction factor Fc based on the compressor's operating speed. The manufacturer provides a table like the one shown in [Fig. 2] giving the value of the correction factor Fc to be applied as a function of the compressor's operating speed. According to the table in [Fig. 2], if the compressor operates at 970 rpm, for the general recommended overhaul interval of 12,600 hours, the actual corrected overhaul interval is 1.5 x 12,600 = 18,900 hours.

[0012] Thus, the equation giving the corrected revision interval is: Ir = Ig * Fc, with: L: the actual revision interval; Ig: the general revision interval given by the manufacturer via curves; Fc: the correction coefficient provided by the manufacturer and a function of the operating speed of the compressor, and can be defined as Fc = 1460 / actual operating speed of the compressor (1460 rpm being considered by the manufacturer as the optimal operating speed of the compressor).

[0013] However, the value of the correction factor Fc may be too high in the case of a compressor operating with a variable speed drive and at low load which requires only a low rotational speed, inducing a high revision frequency.

[0014] In addition, the values ​​of the general revision interval Ig are given by the manufacturer only in the form of curves, without indication of how these curves are obtained.

[0015] The values ​​of the revision intervals are therefore given by the manufacturers to correspond to a large majority of operating conditions, which does not always reflect the actual operation of the compressor.

[0016] Thus, in certain situations where the compressor is under heavy load (operation at full load, significant variation in speed or load, mechanical variation without a variable speed drive, number of starts, etc.), the recommended overhaul interval may be insufficient, leading to premature wear of the parts. Conversely, the compressor may sometimes be under very little load, and the manufacturer's recommended overhaul frequency may be high, resulting in significant maintenance costs. Description of the invention

[0017] The invention thus aims to provide an alternative solution for determining optimized overhaul intervals for an open-type industrial compressor of the reciprocating or continuous flow type (piston or screw). This optimization makes it possible, in particular, to ensure optimal compressor operation and to limit the risks of premature wear or unexpected failures that could lead to a total and unforeseen shutdown of the compressor.

[0018] Adjusting the overhaul interval to the actual operating conditions of the compressor impacts both the operating costs associated with compressor overhauls (ordering spare parts, personnel working on the compressor) and the compressor's energy efficiency. This adjustment also helps to limit unforeseen repair work during a mechanical overhaul that would otherwise require machining.

[0019] The invention thus relates to a method for estimating the actual mechanical overhaul interval of an open-type industrial compressor with reciprocating or direct flow (or piston, screw, or single-screw type). The method comprises: - the determination of the evaporation pressure Po and the condensation pressure Pk of the compressor in operation; - the determination of the actual revision interval Ir by applying a starting coefficient Fd and a correction coefficient Fc to a general revision interval Ig; . the general revision interval Ig being dependent at least on the evaporation pressure Po and the condensation pressure Pk of the compressor in operation; The correction coefficient Fc is a function of the compressor load during operation; and . the start-up coefficient Fd being a function of a predicted number of compressor starts over a predefined time interval, for example over a given operating year, and of a predicted total number of compressor operating hours during the same predefined time interval, for example over the given operating year; - the determination of a future revision time, by a compressor control unit, based on the value of the actual revision interval Ir determined, and the date of the last revision (or update of revision times).

[0020] Thus, the revision interval is determined taking into account the actual operating conditions of the compressor and in particular the load.

[0021] According to one embodiment, the actual overhaul interval Ir can be determined by further applying a reliability coefficient Ff to the general overhaul interval Ig. The reliability coefficient Ff is particularly representative of the mechanical reliability of the compressor model under consideration. In other words, when the compressor model is known and / or a sufficient amount of data relating to the compressor's operation or behavior over a long period is available, taking into account the compressor's reliability coefficient allows for a more accurate estimation of the overhaul interval.

[0022] In practice, the reliability coefficient Ff is specific to a compressor model and can be determined by taking into account metrological measurements relating to the compressor or compressor parts. These measurements are collected beforehand over a predefined period, for example, 10 years. This metrological data relates, for example, to the rotational play on a power regulating spool with a tolerance of 0.10 mm. For example, the reliability coefficient Ff of a compressor model can take into account an estimated or actual return rate for dismantling or repair of that compressor model, or an average time between two failures of the compressor or a compressor part, over a predefined period (for example, 10 years). This return rate can be expressed as a notation with a value between 1 and 10.

[0023] Thus, the general revision interval is adjusted taking into account the actual operating conditions of the compressor, and in particular the variation of the compressor load, and the mechanical reliability of the compressor model considered.

[0024] Advantageously, the general revision interval Ig can further depend on a precariousness coefficient i of negative value and a function of the evaporation pressure Poet of the condensation pressure Pk determined.

[0025] In other words, the actual revision interval Ir can be defined by:

[0026] [Math.l] Ir = Ig(i)*[Ff+Fc]

[0027] Or

[0028] [Math.2] Ir = Ig(i)*[Ff+Fc+ Fd]

[0029] Ir being the actual revision interval; i being the precariousness coefficient, i < 0, a function of the evaporation pressure Po and the condensation pressure Pk determined; Ig(i) being the general revision interval, a function of the precariousness coefficient i; Ff being the compressor reliability coefficient; Fc being the correction coefficient; Fd being the starting coefficient.

[0030] In practice, the determination of the actual revision interval Ir can be carried out using two methods: - by a static method (averaged over a one-year period), that is, by determining an average of each of the variables involved in determining Ir, over one year, so that the value of Ir is fixed for one year; or - by a dynamic method (continuous, derivative over short periods), that is to say that Ir is determined over intervals of short periods and the value of Ir is updated, so that the value of Ir can evolve over the year.

[0031] Thus, determining the actual overhaul interval between two mechanical overhauls takes into account measurements of parameters that can affect the compressor's operation. Furthermore, the overhaul interval can be determined continuously, particularly in real time, or at predefined frequencies. In other words, the actual overhaul interval can be a dynamic value.

[0032] According to one variant, the general revision interval Ig(i) can be determined by further applying a fixed-value technological factor Ft indicative of the type of compressor, namely reciprocating or continuous flow compressor (piston or screw or single-screw compressor).

[0033] In practice, a screw compressor generally offers greater durability compared to a piston compressor, due to a smaller number of parts mobiles. Thus, as an example, the technological factor Ft can be set to a value of 1 for a piston compressor, and to a value between 2 and 3 for a screw or single-screw compressor.

[0034] The precariousness coefficient i can be advantageously determined by the following formula:

[0035] [Math.3] z = (Pk - n) / (ln(P^ + k)

[0036] n being a constant between -23 and -21; k being a constant between -6 and -3.

[0037] Advantageously, for an open piston, screw, or single-screw compressor, the correction factor Fc is determined with the following equation:

[0038] [Math.4] f c = [r„ *(i - cj)]

[0039] Fv being a constant representing the existence or absence of premature wear due to the absence or presence of a speed variator in the compressor; Ch being a compressor load in % (between 0 and 100%).

[0040] In practice, the load can be measured in the dynamic case, or calculated in the static case, or even predefined.

[0041] The correction factor Fc is thus dependent on the presence or absence of a variable speed drive, as well as on the compressor load during operation. In particular: - without a speed variator: the variation will be carried out mechanically by the regulating slide valve for screw compressors and by the lifting of the valves for piston compressors. This variation in mechanical power causes premature wear of the compressor (due to friction, heating, vibrations, etc.); - with variable speed drive: the variation will no longer be done mechanically by the power regulation spool and the rotation speed can be reduced or adapted to the compressor load, positively impacting the compressor's lifespan (related to the limitation of friction).

[0042] Thus, the variation factor Fv reflects the possible existence of premature compressor wear induced by the absence of a speed variator in the compressor. In practice, the value of the variation factor Fv can be determined through feedback from mechanics and by statistical analysis of metrological readings relating to the compressor or compressor parts, collected beforehand over a predefined period, for example, 10 years.

[0043] For example, the variation factor Fv can be a fixed positive value less than 1 when the compressor incorporates a variable speed drive, and Fv can be a fixed negative value, with an absolute value less than 1, when the compressor does not incorporate a variable speed drive. For example: - in the presence of a speed variator: Fv can be between 0.1 and 0.5; - in the absence of a speed variator: Fv can be between -0.5 and -0.1.

[0044] The invention also relates to a system for estimating a mechanical overhaul interval of an open-type industrial compressor with alternating or continuous flow, the system comprising a compressor control module, the control module being coupled to at least means for determining the actual operating speed of the compressor, means for determining the evaporation pressure Po and the condensation pressure Pk of the compressor in operation, means for determining the compressor load, and a database, the module being configured to implement the estimation method described above.

[0045] The invention may also relate to a method of generating or constructing a virtual model, in the form of a digital twin, of the compressor or a more complete installation integrating the compressor, implementing the estimation method presented above.

[0046] In one variant, the construction of the virtual model may include the construction of an adjusted operating hour meter of the compressor, taking into account the vibratory behavior of the compressor, and the theoretical quantity of oil consumed by the compressor, during a predefined time. Brief description of the drawings

[0047] The present invention and its advantages will become more apparent from the following description of several embodiments given by way of non-limiting examples, with reference to the accompanying drawings, in which:

[0048] [Fig. 1] is an example of a curve diagram indicating the maximum number of operating hours of the compressor between maintenance operations, as a function of condensation and evaporation temperatures;

[0049] [Fig.2] is an example of a table giving the correction factor as a function of the compressor rotation speed;

[0050] [Fig.3] is an example of a curve diagram indicating the general revision interval Ir(i), as a function of the condensation pressures Pk and evaporation pressures Po;

[0051] [Fig.4] is a simplified flowchart representing the steps of the process for determining the actual revision interval according to one embodiment;

[0052] [Fig.5] is a simplified block diagram of the system according to one embodiment;

[0053] [Fig.6] presents curves representing the evolution of cumulative hours by the hour meters, and the theoretical oil leakage rate, according to an embodiment;

[0054] [Fig.7] presents curves representing the evolution of the cumulative hours by the hour meters, and their difference, according to a method of implementation. Description of the implementation methods

[0055] The determination of the actual overhaul interval Ir of an open-type industrial piston, screw or single-screw compressor, according to an embodiment, takes into account a precariousness coefficient i, a correction factor Fc, but also a reliability factor Ff, and / or a starting factor Fd.

[0056] Thus, with reference to [Fig.4], the method for determining the actual revision interval Ir according to one embodiment can thus comprise the following operations: - the determination 1 of the evaporation pressure Po and the condensation pressure Pk of the compressor in operation; - the determination of the different coefficients necessary for the calculation of Ir; - the determination 3 of the actual revision interval Ir by applying the different coefficients to a general revision interval Ig; - the determination 4 of a future revision time, by a compressor control unit, as a function of the value of the actual revision interval L determined, and the date of the last revision (or update of revision times).

[0057] In one embodiment, the actual revision interval Ir can be determined via the following general equation:

[0058] [Math.5] I^Igd^F +Fc + f2 JJ

[0059] Ir being the actual revision interval; i being a coefficient of precariousness; Ig(i) being a general revision interval, a function of the precariousness coefficient i; Ff being a factor in compressor reliability; Fc being a correction coefficient; Fd being a starting coefficient.

[0060] The different factors and coefficients will be presented below. Precariousness coefficient i

[0061] The precariousness coefficient i can be determined by the following formula:

[0062] [Math.6] z = (Pk - n) I (ln(P^ + k)

[0063] i < 0 Poest is the evaporation pressure of the compressor in operation, and which can be measured by a sensor; Pk is the condensation pressure of the compressor in operation, and which can also be measured via a sensor; n being a constant between -23 and -21; k being a constant between -6 and -3. General revision interval Ig(i)

[0064] The general revision interval Ig(i) can be determined via the following formula:

[0065] [Math.7] lg = [(«* i3) + (b * i2 ) + (c * i) + d] * Ft

[0066] i is the precariousness coefficient defined above; Ft is a fixed-value technological factor indicating the type of compressor, namely piston compressor or screw compressor or single-screw compressor; a, b, c and d being constants.

[0067] In particular, the technological factor Ft can be set to a value of 1 for a piston compressor, and to a value between 2 and 3 for a screw or single-screw compressor.

[0068] The constant a can be between 0.2 and 1. The constant b can be between 35 and 40. The constant c can be between 1265 and 1275. The constant d can be between 20725 and 20735.

[0069] In practice, the value of the general overhaul interval Ig(i) can be given via a curve diagram such as that illustrated in [Fig. 3] giving the value of the general overhaul interval Ig as a function of the evaporation pressure Po and the condensation pressure Pk. Thus, according to [Fig. 3], the general overhaul interval Ig is 8000 hours for compressor operation corresponding to the curve Co.

[0070] This formula for determining the general revision interval Ig(i) is valid for all types of refrigerant. Reliability factor Ff

[0071] The reliability factor Ff represents the mechanical reliability of the compressor model under consideration and is a function, for example, of an estimated or actual rate of return for dismantling or repair of that compressor model. It can be determined by taking into account metrological measurements relating to the compressor or compressor parts, collected beforehand over a predefined period, for example, 10 years. This reliability coefficient Ff can be obtained by applying calculation laws. The reliability of mechanical systems, or be based on a study of the behavior of the compressor or compressor components, taking into account feedback from qualified personnel involved in compressor maintenance, over a predefined period, for example, 10 years. The return rate can be expressed as a rating from 1 to 10.

[0072] For example, the reliability factor Ff can be determined by the following equation:

[0073] [Math. 8] F f - [a * nt) + / ?

[0074] nt being a notation of the compressor model considered, and generally takes a value between 1 and 10. This notation is an objective data representative of the return rate for dismantling or repair of the compressor: a being a constant between 0.02 and 0.06; [3 being a constant between 0.5 and 0.7

[0075] The determination of the reliability coefficient of a compressor model can be based on the causes and / or consequences of failures or returns of the compressor to the factory or for repair, as well as on the metrological deviations observed between machines of the same model in ideal regimes.

[0076] For example, the reliability coefficient can be based on data relating to the impact of water hammer on the premature wear of a given compressor model, under different operating conditions (e.g., compressor operating with or without an economizer, with economizer, without economizer). A statistical rule, such as the binomial distribution, can be implemented to highlight the significance or importance of a physical phenomenon observed on the compressor. Correction factor Fc

[0077] The correction factor Fc allows taking into account the presence or absence of a speed variator, as well as the compressor load.

[0078] The correction factor Fc can be determined with the following equation:

[0079] [Math.9] Fc = (F,* (l - C„))

[0080] Fv a variation factor representative of the existence or absence of premature wear due to the absence or presence respectively of a speed variator in the compressor; Ch is the compressor load in % (between 0 and 100%).

[0081] For example: - in the presence of a speed variator: Fv can be between 0.1 and 0.5, for example equal to 0.2; - in the absence of a speed variator: Fv can be between -0.5 and -0.1, for example equal to -0.2. Starting coefficient Fd

[0082] The starting coefficient Fd depends on the predicted number of compressor starts over a predefined time interval, for example over the operating year considered, and can be expressed as follows:

[0083] [Math. 10] ~ \ nb;*h /

[0084] nbd being the number of compressor starts during the predefined time interval, for example per year; nbh being the number of operating hours of the compressor during the predefined time interval, for example per year; m being a constant equal to 7.5 corresponding to the number of minutes to be subtracted from the general revision interval Ig; h being a constant equal to 60. Expanded form of the real interval Ir

[0085] The actual interval Ir can thus be the product of the general interval Ig(i) with the reliability factor Ff, adjusted with the correction coefficient Fc and the starting coefficient Fd.

[0086] Thus, according to one embodiment, the revision interval Ir is given by the following equation:

[0087] [Math. 11] Ir = It(iAFc

[0088] Or

[0089] [Math. 12] Ir= [ (0.05* / zt + 0.65)] + [F*(l-Ch)*Ig(i) ] + [ - ] Estimation system

[0090] All of these operations can be implemented in a control module of an estimation system, illustrated in [Fig. 5]. The control module 5 can in particular be coupled, for example, to means 6 for determining the actual operating speed of the compressor, means 7 for determining the evaporation pressure Po and the condensation pressure Pk of the operating compressor, means 8 for determining the load of a compressor 9, and a database 10 or a memory.

[0091] The various parameters (curve diagram, the different constants, a table giving the notation nt of different compressor models, the variation factors, etc.), as well as the equations involved in determining the actual revision interval Ir, can be stored in the database.

[0092] The control module 5 is configured to determine the actual revision interval L by applying the above equations, and to determine future revision times based on the determined actual revision interval Ir and the date of the last revision. Digital twin

[0093] The estimation method presented above can also be implemented for the generation or construction of a virtual model, in the form of a digital twin, of the compressor or a more complete installation integrating the compressor.

[0094] Thus, in addition to the data necessary for estimating the revision interval according to the invention, other data or measurements can be used for the simulation of the life cycle of the compressor or the installation.

[0095] Such data can be quantitative data, such as, for example, the vibration behavior of compressors via a vibration sensor, the theoretical quantity of oil consumed by the compressor, etc.

[0096] Such data may also be qualitative data, such as, for example: - the rating of compressors which results from an expertise of the Applicant benefiting from global feedback concerning different models of compressors; - the rating relating to the actual oil consumption at the compressor seals compared to the theoretical consumption during operation.

[0097] In practice, this modeling can enable anomaly detection and / or assistance in controlling the compressors or the installation, and identify areas for improvement in operating conditions. For example, it is possible to adjust the rotation speed, modify the number of daily starts allowed, reduce the compression ratio, put the compressor in backup mode, etc., in order to operate the compressor under more favorable conditions.

[0098] In one variant, the modeling may also include the construction or generation of an adjusted operating hour meter for the compressor. The modeling of the actual adjusted hour meter may take into account the quantitative data mentioned above.

[0099] The hour meter defines the number of hours the compressor can be in operation in a day. This hour meter is distinct from the hourly interval of revision. Thus the revision time interval which can be determined according to the method of the invention, and the hour counter can be modulated.

[0100] In practice, it is possible to adjust the speed of the counter. For example, the actual counter can advance faster if the actual operating conditions of the compressor are considered unfavorable and advance more slowly if the actual operating conditions of the compressor are considered favorable.

[0101] An example illustrating the evolution of the hour meters is shown in Figures 6 and 7. The dates are given on the abscissa, and the quantity of oil leakage (ml), the number of hours of the hour meters (h) and the difference between the hour meters (Nh) are given on the ordinate.

[0102] The curve Cl (solid line curve) represents the evolution of the number of hours (h) of the theoretical hour meter of the compressor; Curve C2 (dashed curve) represents the evolution of the number of hours (h) of the adjusted real hour meter generated by the modeling (digital twin); Curve C3 gives the theoretical oil leakage rates; Curve C4 represents the evolution of the difference in number of hours (Nh) between the two curves Cl and C2.

[0103] The solution presented above can be implemented in a more comprehensive Intelligent Collaborative Factory solution.

Claims

Demands

1. A method for estimating the actual mechanical overhaul interval of an open-type industrial compressor with reciprocating or direct flow, comprising: - determining (1) the evaporating pressure Po and the condensing pressure Pk of the compressor in operation; - determining (3) the actual overhaul interval Ir by applying a starting coefficient Fd and a correction coefficient Fc to a general overhaul interval Ig; . the general overhaul interval Ig being dependent at least on the evaporating pressure Po and the condensing pressure Pk of the compressor in operation; . the correction coefficient Fc being a function of the compressor load in operation; and .the start-up coefficient Fd being a function of a predicted number of compressor starts over a predefined time interval, for example over a year of operation considered, and of a predicted number of total operating hours of the compressor during the same predefined time interval, for example over the year of operation considered; - the update (4) of a future revision time based on the value of the actual revision interval Ir determined, and the date of the last revision.

2. Estimation method according to claim 1, wherein the actual overhaul interval Ir is determined by further applying a reliability coefficient Ff to the general overhaul interval Ig, the reliability coefficient Ff being representative of the mechanical reliability of the compressor or of a set of compressor parts.

3. Estimation method according to claim 1 or 2, wherein the general revision interval Ig can further be a function of a precariousness coefficient i of negative value and a function of the determined evaporation pressure Po and condensation pressure Pk of the compressor in operation.

4. Estimation method according to claim 3, wherein the actual revision interval is determined by applying the following equation: Ir being the actual revision interval; i being the precariousness coefficient, i < 0, a function of the determined evaporation pressure Po and condensation pressure Pk; Ig(i) being the general revision interval, a function of the precariousness coefficient i; Ff being the compressor reliability factor; Fc being the correction factor; Fd being the start-up factor.

5. Estimation method according to any one of claims 1 to 4, wherein the general revision interval Ig(i) is determined taking into account a technological factor Ft indicative of the type of compressor, namely reciprocating or continuous flow compressor.

6. Estimation method according to any one of claims 1 to 5, wherein the precariousness coefficient i can be advantageously determined by the following formula: i = (P, - ri) / Qn(P 0) + k) n being a constant between -23 and -21; k being a constant between -6 and -3.

7. Estimation method according to any one of claims 2 to 6, wherein the reliability coefficient Ff is given by: Ff = (0.05 * nt) + 0.65, nt being a notation of the compressor model considered, and has a value between 1 and 10.

8. Estimation method according to any one of claims 1 to 7, wherein the correction factor Fc is determined with the following equation: Fc = Fv * (1 - Ch) Fv being a constant representing the existence or absence of premature wear due to the absence or presence of a speed variator in the compressor; Ch being a compressor load in %.

9. Estimation method according to claim 8, wherein the variation factor Fv is representative of the presence or absence of premature wear due to the presence or absence of a variable speed drive in the compressor, the variation factor Fv being equal to a fixed positive value less than 1 when the compressor incorporates a variable speed drive, and equal to a fixed negative value, of absolute value less than 1 when the compressor does not incorporate a speed variator.

10. System for estimating a mechanical overhaul interval of an industrial open-type compressor (9) with alternating or continuous flow, the system comprising: a compressor control module (5) coupled at least to means (6) for determining the actual operating speed of the compressor, means (7) for determining the evaporation pressure Po and the condensation pressure Pk of the operating compressor, means (8) for determining the load of the compressor (9), and a database (10), the control module (5) being configured to implement the estimation method according to any one of claims 1 to 9.

Images