EP2702272B1 - Pump system - Google Patents

Description

The invention relates to a displacement pump system with a positive displacement pump module according to the preamble of patent claim 1 (hereinafter also referred to as pump module), which is preferably designed as a, in particular multi-spindle, screw pump. In addition to the pump module, the pump system includes a drive module for driving the pump module, the drive module being replaceable independently of the pump module, i. releasably connected to the pump module. The drive module comprises, in addition to an electric drive motor, a frequency converter assigned thereto for regulating or setting a drive motor rotational speed. Furthermore, the pump system comprises control means with a logic and a controller for generating a manipulated variable as a function of a reference variable and at least one actual operating parameter, such as a fluid pressure and / or a volumetric flow. Preferably, the pump system as Führungsgrößenvorgabemittel a control room, so a higher-level control system. In addition or as an alternative to a process control system, the reference variable can be preset manually, for example by a corresponding setting on the control means and then generated by the control means itself and / or by a simple voltage source separate from the control means and outputting an electrical voltage value as a reference variable.

Today's displacement pump motors for driving positive displacement pumps include a frequency converter with integrated controller, which is able to control the input signal, in particular a voltage signal for the frequency converter in dependence on a measured actual operating parameter and a reference variable to be achieved. In this case, the controller transmits the manipulated variable determined as a function of the reference variable to the frequency inverter "without criticism". The problem with this is that the controller associated with the frequency converter is designed today only engine-specific, that is not optimized with respect to the actual interest in Verdrängerpumpensystemen positive displacement pump. This can lead to problems with positive displacement pump systems, since positive displacement pumps in principle pose an increased risk for the pump itself and / or for further process units compared to centrifugal pumps. This is due to the characteristic behavior different from turbomachines attributed by positive displacement pumps. In principle, even in extreme cases, this can lead to complete self-destruction or sustained disruption of the positive-displacement pump, especially if signs of damage are not detected in time.

Also, the influence of the directly resulting from the reference variable (target specification) manipulated variable signal on the quality of the delivery fluid in known positive displacement pumps is not considered.

In addition, it is disadvantageous in known pump system that on the respective, the frequency converter comprehensive, electric drive motor must be made a specific programming of the logic of the control means, which always represents only a compromise in terms of optimized properties of the pump module. In known pump systems, it is always possible to replace the drive module independently of the pump module - a replacement of the control means is not possible by their integration in the frequency converter of the electric motor.

The document DE 20 2005 001746 discloses a control system for pumps with a frequency converter for adjusting an engine speed.

Based on the aforementioned prior art, the present invention seeks to provide a pump system that guarantees increased safety for other process units and for the pump module itself. In addition, the variability for the end customer should be increased and an optimized in terms of optimum functionality and longevity of the pump module speed control should be possible.

This object is achieved in terms of the pump system with the features of claim 1. Advantageous developments of the invention are specified in the subclaims. All combinations of at least two features disclosed in the description, the claims and / or the figures fall within the scope of the invention. In order to avoid repetition, features disclosed according to the device should be regarded as disclosed according to the method and be able to be claimed. Likewise, according to the method disclosed features should be considered as device disclosed and claimed claimable.

The invention is based on the idea of separating the control means previously integral with the frequency converter, in order to separate a control module which is separate from the drive module, i. to obtain independent control module, in which the logic means, possibly with database and, preferably designed as a PI or PID controller, controller is provided, thus independent of the frequency in dependence of a reference variable and at least one actual operating parameter (actual System parameter) to provide an input signal (manipulated variable) for the frequency converter, which is then converted by the drive module, more precisely by the frequency converter by a corresponding Wicklungsbestromung in an engine speed. By means of the invention, it is possible for the first time to be able to exchange or freely select the drive module independently of the control means for generating the desired speed signal. The invention also makes it possible to use very simply constructed frequency converter, which act in the simplest case as a controller that set the predetermined speed of the separate control module speed command, for example, designed as an asynchronous motor by appropriate current influencing. Of course, it is also possible to use previously used "intelligent" frequency converter, but this is then preferably not used in the previous manner, i. be controlled. A possibly contained PI or PID controller of the frequency converter is therefore preferably not supplied with a pressure sensor signal and not with a flow rate signal and not a vibration sensor signal and not with a temperature sensor signal and not with a torque sensor signal, with the aim on this input base a manipulated variable, in particular to generate in the form of a speed command signal - but this control variable is obtained from the separate control module and implemented by the frequency converter in a conventional manner in an engine speed.

In addition to the simplified interchangeability of the drive module independent of the actual control (control means or control module) for generating the variable to be converted by the variable manipulated variable (possibly a later yet to be explained corrected manipulated variable), formed according to the concept of the invention Verdrängerpumpensystem further significant advantages. It is thus possible for the first time to use a logic (logic means) optimized specifically for the pump module with suitable pump module-specific software and a controller optimized for the actual pump process, preferably an optimally selected PI or PID controller. Prefers is the, in particular a microcontroller comprehensive logic associated software that is specially adapted to the pump module used, so that the actual drive motor can be replaced independently of the pump module and the control module, without affecting the configuration of the pump module via the control module. Alternatively, it is conceivable to provide different software for different pump modules, or comprehensive software in which the pump module used in each case, but preferably a suitable menu control, can be selected. A specific adaptation of the control module to the respectively used pump module, ie a hardware modification is not necessary.

Regardless of the design of the drive module, the control module for the first time offers the possibility of monitoring the pump module independently of any control room and regulating it by means of speed control, wherein the logic is preferably designed to detect impermissible operating conditions (impermissible system actual parameters) and If necessary, reduce the pump module by adapting the setpoint speed to be set by the frequency inverter to a safe operating point by reducing the setpoint speed as the input signal for the frequency inverter.

Preferably, the logic is designed in such a way that upon detection of a critical system actual parameter (in particular by comparison with limit values stored in this database) either one, in particular stored in a database, safe, preferably a (further) damage to the pump module preventing setpoint speed or Assigns manipulated variable or an adjusted system setpoint parameters due to which the integral controller of the control module outputs a, preferably lower, setpoint speed as a manipulated variable. The setpoint speed specified by the logic can in extreme cases be zero, but is preferably located in a speed range greater than zero, so that the actual process can continue despite critical system actual parameters. By using the control module designed according to the concept of the invention, a sudden total failure with consequential damage and possibly resulting production failure or operational failure can be minimized.

In a further development of the invention, a control module higher-level control (control room) are provided with advantage as Führungsgrößenvorgabemittel, with the one due to an actual operating parameter predetermined by the control module manipulated variable (or a later to be explained corrected manipulated variable) is over-tunable, for example, not to endanger the process as such. In other words, the control room can preferably specify a control variable other than that specified by the control module, in particular a speed specification, which is then converted by the frequency converter into a rotational speed of the drive module. In this case, preferably the regulation of the speed setpoint signal is not carried out in the control module, but in the control room. It is also conceivable that the control module is used by the control room as an auxiliary controller, such that the system nominal parameter to be adjusted is determined by the control room, ie a system nominal parameter provided by the control module is overruled, in particular to have negative effects on the actual process in which The pump module is integrated, not to endanger.

Preferably, the control room and / or the control module is designed to output a start and / or stop signal for the motor of the drive module.

In principle, the control module or its intelligence (logic) is preferably configured in such a way that the main aim is to ensure a long service life of the pump module or to prevent lasting damage from this. This is realized with advantage in such a way that, if a critical actual operating parameter was measured and the manipulated variables were recognized as critical by the logic, this is either dictated by this one setpoint speed and converted by the drive module, or influenced by the logic of the system setpoint parameter The goal is that by modifying the controller of the control module regulates a lower target speed. However, it may be necessary to override the appropriate "suggestions" of the control module and, consciously risking damage to the pump module, not jeopardize the process as such or at least maintain it for some time. This control task is then taken over by the control room, which can override the control module from case to case or under predetermined conditions, for example such that instead of a provided by the logic of the control module target speed directly from the control room predetermined manipulated variable, in particular target speed signal to the frequency the drive module is passed (the control of this signal is preferably taken over by the control room) and / or in that instead of one of the logic of the control module in dependence If a measured system actual parameter is actually provided, another (corrected) manipulated variable is specified by the control room as the input value for the controller of the control module.

It is very particularly preferred if the control module is arranged spatially separated from the drive unit in a separate control module housing from the drive unit and / or the frequency converter, preferably at a minimum distance of 0.5 m, preferably 1 m or more. The control module housing is preferably assigned at least one, preferably digital, signal input for receiving the actual operating parameter, for example from a sensor module and / or from an optionally provided control room. Additionally or alternatively, the control module housing is assigned a, in particular analog, signal input for receiving an actual operating parameter and / or a command variable from the control room. Preferably, the housing is also assigned a manipulated variable output signal output, in particular a speed setpoint signal output via which the manipulated variable generated by the controller of the control module (possibly a corrected manipulated variable) in the direction of the frequency converter of the drive unit and / or a speed setpoint signal in the direction or respectively predetermined by the control room . Can be output for the drive unit.

In a further development of the invention is advantageously provided by the controller in response to a command variable, for example, a desired volume flow or a desired pressure of the fluid generated control variable, preferably a voltage signal not directly, ie uncritically or without plausibility, ie review as an input signal to the frequency converter, but the manipulated variable, or a later to be explained by possibly additionally provided, in particular second, correction means obtained corrected manipulated variable or according to a functional relationship from the manipulated variable or the corrected manipulated variable determined comparison value with at least a first limit (pump protection limit) to compare the at least one first limit value reflects a risk potential for the positive displacement pump and / or another process unit. In other words, exceeding or falling below the first limit value (with a defined probability) would result in a predetermined defect state of the positive displacement pump. It is advantageous in this case if the first limit value is not a static limit value, ie a fixed or fixed limit value (which of course additionally a comparison can also be made with such fixed limit values), but a dynamically determined limit value, which is calculated on the basis of an actual operating parameter. In other words, the limit value is currently calculated as a function of a plurality of actual operating parameters, wherein these actual operating parameters may be the first actual operating parameter, ie an actual controlled variable from the controlled system, on the basis of which the controller determines and corrects the manipulated variable at least one further, ie another actual operating parameter, which is either measured directly by means of a sensor or calculated on the basis of an actual value, in particular simulated. Stated another way, the advantage of the invention is that it not only works with static limits, but according to the invention takes into account that the limits are subject to dynamics, ie can change in operation of the positive displacement pump in response to changing actual operating parameters. In the event that the thus determined first (pump protection) limit value is exceeded or fallen below by a certain amount, a corrected manipulated variable is provided with the aid of first correction means, with which preferably the manipulated variable generated by the controller or an already previously corrected manipulated variable that has been generated, for example, by second correction means is overwritten. It is particularly expedient if the corrected manipulated variable assumes the maximum or minimum permissible value, that is to say preferably a first, currently calculated limit value in order to come as close as possible to the reference variable or more precisely the manipulated variable directly resulting from the reference variable. In other words, the corrected manipulated variable is a quantity covered by a first limit value (preferably a correspondingly limited voltage signal).

In addition to the comparison of the manipulated variable, a corrected manipulated variable, or a currently determined comparison value with a first, the Verdoller pump protection ensuring limit can be determined by the controller in response to the command variable manipulated variable or a corrected manipulated variable, (for example, a correcting variable received from first correction means, in particular the corrected correcting variable output by the first correcting means or a currently calculated comparative value are compared with at least one second limiting value (conveying fluid protection limit value) whose adherence or not exceeding is to ensure the quality of the conveying fluid. or falling below the second limit (with a defined probability) a predetermined Affect the quality parameters of the pumped with the positive displacement fluid. If comparisons are used to determine that the at least one second limit value has exceeded or fallen below by a predetermined amount (depending on whether it is a maximum or minimum limit value), a corrected manipulated variable is output by second correction means, which is preferably either directly or indirectly in the form of a comparison value to the comparison with the at least one first limit value or as an input variable (target specification) is passed to the frequency converter. The manipulated variable generated by the controller or the manipulated variable obtained from upstream further, for example, the first correction means, is preferably overwritten by the corrected manipulated variable of the second correction means.

It is also essential here that the second limit value is not a fixed, stored limit value, but rather a second limit value calculated on the basis of a plurality of current actual operating parameters, wherein the actual operating parameters used in the calculation are the first actual operating parameter, in particular an actual control variable, and additionally a different (further) measured actual operating parameter or an actual operating parameter calculated, in particular based on an actual value. Of course, in addition a comparison of a manipulated variable, a corrected manipulated variable, a comparison value and / or an actual operating parameter can be performed with a fixed delivery fluid limit and in case of exceeding or falling below a correction of the manipulated variable or the corrected manipulated variable can be performed.

As already indicated, it is within the scope of the invention to adjust a manipulated variable, a corrected manipulated variable or a comparison value either against at least one first (pump protection) limit value or only against a second (conveying fluid protection) limit value or alternatively against both at least one first (pump protection) limit value. ) Limit value and additionally against at least a second (Förderfluidschutz-) limit value, which in turn alternatively first against at least a first threshold and then subsequently against at least a second threshold can be compared, or conversely first against a second threshold and subsequently against a first threshold.

It is therefore essential to assign to the controller for generating a manipulated variable a logic (logic means), which ensures that the controller output signal (control variable) initially compared with at least a first and / or at least a second limit (pump protection limit and / or Förderfluidschutz limit) is, wherein the at least one first and the at least one second threshold current, ie is calculated taking into account a measured or calculated actual operating parameter and that, in the event that an above or below the at least one first limit value and / or the at least one second limit value is determined, generates a corrected manipulated variable and then this instead of the from the controller originally generated manipulated variable or instead of an already previously corrected manipulated variable as an input signal to the frequency converter (frequency converter) is passed, which energizes the positive displacement motor based on this target specification.

In principle, it is possible to execute the logic means in hardware separately from the controller, for example in the form of a microcontroller separate from the controller. Preferred is an embodiment in which the controller and the control means are realized by a common microcontroller or comprise a common microcontroller.

As will be explained later, it is particularly preferred if in the calculation of the at least one first limit value and / or the at least one second limit value positive displacement pump-specific parameters, in particular geometry parameters, such as a gap, and / or a spindle diameter are included. For this purpose, it is particularly useful if in a (non-volatile) memory, in particular an EEPROM, the logic means several sets of system parameters are stored, which are specific for different positive displacement pumps (ie each record is specific to a positive displacement pump), in particular for different types and Sizes of positive displacement pumps and which can be selected between these data sets, in particular in a basic configuration, for example via a menu control. In this way it is possible to use the same control means in connection with different positive displacement pumps.

For the first time, the control means enable possible negative effects on current, changing operating parameters of a reference variable or the effects of a manipulated variable directly resulting from the reference variable on the integrity of the positive displacement pump and / or on the product quality, i. the quality of the means of the positive displacement pump delivered delivery fluid on the basis of a comparison with a situational determined, i. to recognize itself in the course of time changing limit and counteract if necessary, by the immediate from the reference variable resulting from the controller manipulated variable (voltage signal) is immediately converted by the frequency converter in a positive displacement motor speed when detecting a hazard potential or the positive displacement motor by controlling a contactor is simply turned off, but instead by one, in particular reduced, or increased in response to a first operating parameter and at least one, preferably measured, further actual operating parameter calculated corrected manipulated variable (preferably greater than zero) is passed to the frequency converter. The corrected manipulated variable is preferably the first or second limit value calculated by the jointly or alternatively provided first or second limit value adjusting means.

wobei

• n : Pumpendrehzahl
• p : Förderfluiddruck in Druckleitung bzw. Förderfluiddruckdifferenz an der Pumpe Exponent a, Faktor b und c Konstanten der Verdrängerpumpe,
• k: Faktor der Förderfluidschmierfähigkeit
• υ: Förderfluidviskosität

The physical quantities (parameters) of the pump speed, the delivery fluid viscosity and the delivery fluid pressure are in the following physical relationship, ie are mutually interdependent: $$n={\left(\frac{p}{k•b•c•{\upsilon }^a}\right)}^2$$

in which

• n: pump speed
• p: conveying fluid pressure in pressure line or conveying fluid pressure difference at the pump exponent a, factor b and c constants of the positive displacement pump,
• k: Factor of conveying fluid lubricity
• υ: conveying fluid viscosity

According to a preferred embodiment, it is provided that the control means take into account all the above parameters for controlling the frequency converter, wherein preferably the pump speed in the form of the manipulated variable is taken into account finds, the conveying fluid pressure, preferably measured at or near the pressure port or alternatively calculated from other parameters, as the first actual operating parameter and the conveying fluid viscosity or a parameter, in particular a fluid parameter to which the conveying fluid viscosity is in a physical context, in particular the delivery fluid temperature as the second operating parameter, wherein the aforementioned first actual operating parameter, ie the conveying fluid pressure and the further actual operating parameter, preferably the conveying fluid viscosity or the conveying fluid temperature are taken into account by means of the first limiting value specification means in order to calculate the first limiting value whose exceeding or falling below a Deffektzustand the positive displacement pump could have resulted. The comparison means then compare the control variable output by the controller, ie a speed signal with the first limit value, wherein first correcting means output a corrected manipulated variable, ie a corrected speed signal in the event that the manipulated variable output by the controller, taking into account the conveying fluid pressure and the conveying fluid viscosity or of a parameter related thereto in a functional context. is below, wherein it is the corrected manipulated variable, ie the corrected speed signal is preferably the first, previously calculated using the first threshold value setting means limit value. In the preferred embodiment, a delivery fluid volume flow (or the pump speed reflecting the delivery volume flow) or a delivery fluid pressure are used as reference variables.

This preferred embodiment does justice to the case that frequently occurs in practice that a rapid change in the disturbance, e.g. a sudden flow resistance change leads to a very rapid change in pressure and thus to a rapid change in the torque requirement at the pump. In the case of a rapid pressure reduction for large pump drives, this would lead to a rapid speed increase. An impermissible speed increase can be prevented by taking into account the delivery fluid pressure, preferably measured at the discharge nozzle as a first operating parameter and the direct or indirect consideration of the delivery fluid viscosity as a second operating parameter in the calculation of the first limit, so that damaging the pump fails.

In the case of small drive motors, a very rapid sudden increase in pressure would lead to a rapid speed reduction, whereby the consideration of the aforementioned Erstbetriebsparameters and the aforementioned further operating parameter to a corrected manipulated variable, ie a corrected speed signal leads, whereby damage to the pump can be prevented in this case.

In the case of the realization of the medium protection, the conveying fluid pressure, the delivery fluid volume flow or the rotational speed or also the delivery fluid viscosity or a parameter, in particular a fluid parameter, of which the delivery fluid viscosity is directly dependent, preferably come into consideration. The manipulated variable is preferably the rotational speed or a rotational speed signal, wherein for calculating the limit value, in particular a maximum permissible rotational speed, a delivery fluid volume flow is considered as the first operating parameter and the delivery fluid pressure (in particular measured at the discharge port of the pump) is taken into account as a further actual operating parameter.

As mentioned, the comparison with the at least one limit value can be realized in different ways. Thus, it is particularly preferred if the manipulated variable generated by the controller is used for comparison with the first limit value, or alternatively the corrected manipulated variable output by the first correction means or by the optionally provided further, for example second, correction means. It is also possible not to directly use the aforementioned manipulated variable or a corrected manipulated variable for the comparison, but rather a comparison value which is calculated on the basis of a predetermined functional relationship from the manipulated variable or a corrected manipulated variable. In an analogous manner, it is possible to use the manipulated variable generated by the controller for the comparison with the second limit value or a corrected manipulated variable, wherein the corrected manipulated variable may be the corrected manipulated variable output by the first correcting means, if present, or that of the second correction means output corrected correcting variable. It is also possible to have a comparison value, e.g. calculate a current shear rate based on one of the above values and use this for comparison.

As already indicated, the logic means may be the manipulated variable generated by the controller, a corrected manipulated variable or a comparison value calculated on the basis of the manipulated variable and / or the corrected manipulated variable or an actual operating parameter, in particular the first actual operating parameter and / or the further actual operating parameter also with at least one positive displacement pump associated with the control means, fixed limit value are compared, wherein in the event that such a limit value is exceeded or fallen below by a certain level of correction means, a corrected manipulated variable is output. If the actual operating parameter to be compared is, for example, a measured actual oscillation value and if it exceeds a maximum value (limit value) for the particular positive displacement pump, a corrected manipulated variable is output by the correction means, this manipulated variable correction being corrected by first correction means and / or or may be upstream or downstream by second correction means. In the simplest case, the corrected manipulated variable is a manipulated variable signal which is increased or reduced by a specific factor, or a manipulated variable signal which assumes a value stored in a memory, or a simulated, calculated value for which an overshoot or undershoot of the value Limit value is not expected.

The last-described embodiment of the control means is primarily used to detect a sudden damage or sudden damage of the positive displacement pump. If, for example, a vibration parameter is monitored by sensor means as the measured actual operating parameter and if it exceeds a limit value stored in a nonvolatile memory or preferably alternatively or additionally a limit value determined as a function of a measured actual parameter, then the manipulated variable corresponding to the reference variable is not passed on, but one , For example, reduced by a factor of 2 calculated manipulated variable to operate the positive displacement pump as long as possible without any damage, such as bearing damage occurs or worsened, for which the increased vibration value can be an indication.

With regard to the specific embodiment of the regulator of the control means, which is preferably formed by a microcontroller, there are different possibilities. Preferably, the controller is designed as a PI controller or as a PID controller.

With regard to the selection or design of the first actual operating parameter, which is supplied to the controller for determining a manipulated variable and based on which the first (pump protection) limit value and / or the second (Förderfluidschutz-) limit value is calculated if necessary, and the If necessary, it is used for the calculation of the corrected manipulated variable by the correction means, there are different possibilities. Prefers this first actual operating parameter is a preferably measured, actual controlled variable from the controlled system, in particular a so-called actual main controlled variable, for example an actual pressure of the conveying fluid or an actual pressure difference of the conveying fluid, for example between suction side and pressure side Positive displacement pump or to an actual volume flow of the fluid. The first operating parameter is preferably measured, but can alternatively also be simulated or calculated, in particular from a plurality of further actual operating parameters.

As already explained above, the first and / or second limit value must be calculated not only on the basis of the first actual operating parameter supplied to the controller, but additionally on the basis of a functional relationship on the basis of another (further) actual operating parameter. The at least one further actual operating parameter can be a measured auxiliary variable or, in particular, the frequency converter calculated on the basis of an actual value measured, for example a frequency reference of the frequency converter or a torque reference of the frequency converter. It is also possible that at least one further actual operating parameter is a measured or calculated on the basis of an actual value auxiliary control variable, in particular a speed of the positive displacement motor or a torque of the positive displacement motor. It is also possible for at least one further actual operating parameter to be included in the calculation of the first and / or second limit value and / or in the calculation of a corrected manipulated variable and / or in the calculation of a comparison value by a measured temperature, for example a conveying fluid temperature or a bearing temperature, in particular a rolling bearing of a drive spindle of the positive displacement pump act. It is also possible for the at least one further actual operating parameter to be a measured vibration value. It is also possible for the at least one further actual operating parameter to be a measured or calculated delivery fluid viscosity. It is also possible for the at least one further actual operating parameter to be a measured leakage quantity. It is particularly preferred if not only the first actual operating parameter only a single further actual operating parameter is taken into account in the calculation of a limit value or a corrected manipulated variable but, for example, additionally for the first auxiliary operating parameter two or more further, preferably different actual operating parameters.

For applications of medium protection (preferably not for pump protection applications, the at least one further operating parameter may be a measured actual control variable, for example a measured actual main control variable, for example an actual pressure of the conveying fluid, an actual pressure difference or a actual flow.

If, for example, an actual pressure is measured as the operating parameter, for example an overpressure on the discharge nozzle of the positive displacement pump, too high a pressure can be hazardous to the positive displacement pump, in particular a bursting possibility. In this case, the maximum allowable pressure may be dependent on other actual operating parameters, such as the temperature of the conveying fluid.

Too little pressure at the suction nozzle can be used as a cavitation indicator. Preferably, in addition to the pressure as the operating parameter, the delivery fluid viscosity is taken into account, in particular for metrological reasons representative of the viscosity of the delivery fluid whose measured temperature.

The temperature can thus be additionally or alternatively monitored by a pressure as actual operating parameters. An excess temperature of the conveying fluid can be hazardous to the pump, in particular with regard to a possible bearing damage.

When the limit value calculation and / or the calculation of a corrected control value, the engine speed can be taken into account in accordance with a fixed assignment or function which is directly proportional to the positive displacement pump speed (spindle speed), in particular corresponds to this. Too high or too low a speed can also be a risk, especially if further operating parameters, such as the temperature and / or the pressure exceeds or falls below certain limits.

In addition or as an alternative to the above actual operating parameters, vibrations (vibrations) of the positive-displacement pump and / or of the positive-displacement pump motor can occur be monitored. Excessive vibrations jeopardize the alignment between positive displacement pump motor and positive displacement pump with the possible consequence of bearing damage to the positive displacement pump and / or the positive displacement motor. Even with impermissible vibrations mechanical seal damage is possible. Overall, the life of the positive displacement pump can be reduced by impermissible oscillations, in particular if further actual operating parameters, such as the rotational speed and / or the temperature and / or the pressure exceed or fall below certain limits.

In addition or as an alternative to the above further operating parameters, the viscosity of the conveying fluid, which is functionally related to the conveying fluid temperature, can be taken into account directly or indirectly via the temperature in determining a limit value, a corrected manipulated variable or, if provided, a comparison value. Too low a viscosity can be hazardous to the pump because of the resulting decreasing lubricating properties of the fluid between the spindles. Too high a viscosity may be positive displacement pump motor hazard, so that the torque increases too much. In addition, too high a viscosity (too low a temperature) can be a risk of displacement, for example when using a magnetic coupling, which can break off unnoticed due to too high a viscosity, which leads to the destruction of the positive displacement pump or the magnetic coupling.

In addition to the above-described actual operating parameters, which are measured individually, in groups or preferably together to ensure component protection (positive displacement pump protection) or to ensure or guarantee a delivery fluid quality and taken into account in calculations according to a mathematical function, at least one of the following actual operating parameters be monitored, for example, the torque which is functionally dependent on the viscosity of the conveying fluid. In particular, the torque can be taken into account as an indicator of an increasing displacement of the positive displacement pump.

Additionally or alternatively, the positive displacement pump motor current can be included in the calculation of a limit value, a corrected manipulated variable or, if provided, in a comparison value. The motor current is a simple and inexpensive to measure Size, especially at constant other parameters, such as the viscosity of the torque, which in turn may indicate wear of the pump. Additionally or alternatively, the leakage rate can be monitored. This is based on the idea that each mechanical seal requires a nominal leakage in order to lubricate the static and dynamic components of the mechanical seal. If the leakage rate increases, this can be an indicator of incipient mechanical seal damage.

If not, which is preferred, however, the manipulated variable generated by the controller or the manipulated variable corrected by the correction means should be compared with a first or second limit value, but additionally or alternatively for this comparison a comparative value should be calculated, which is in a functional relationship to the manipulated variable or is the corrected manipulated variable, may be included in the calculation of this comparison value based on a functional relationship of several of the aforementioned actual operating parameters, in particular the first actual operating parameters and at least one of the other actual operating parameters.

It is particularly preferred if the first and / or second limiting value specification means and / or the first or second correction means take into account in their calculations for the displacement pump-specific geometry parameters assigned to the control means, for example a gap width and / or a spindle diameter. Additionally or alternatively, the limit value specification means and / or the correction means may be designed taking into account a delivery fluid parameter stored in a storage, in particular a shearing behavior of the delivery fluid.

Thus, it is advantageous in particular with regard to the monitoring of the quality of the delivery fluid or of the final product produced therewith to take into account the angular velocities of the positive displacement pump spindle when calculating a limit value, a corrected manipulated variable or, if provided, during the calculation of a comparison value. In this case, preferably at least one geometry parameter and the pitch angle of the relevant spindle should be taken into account, since different pitch angles of the spindle at the same engine speed lead to different relative speeds within the positive displacement pump.

Also conceivable is a variant in which the at least one measured actual parameter, for example the first actual operating parameter or a further actual parameter, is not fed directly by sensor means into the control means but at the at least one actual operating parameter to the control means of a process control room is transmitted, in particular, as will be explained later, via a bus system.

It is particularly preferred if, in the calculation of the at least one first and / or at least one second limit value, a shear rate is taken into account, in particular a maximum permissible shear rate stored in a memory and / or a shear rate currently calculated using at least one actual operating parameter according to a functional relationship is taken into account.

As already explained, it is conceivable that, in addition to a dynamic limit value analysis, a static limit value analysis takes place in which the manipulated variable, a corrected manipulated variable, a comparison value or directly a first operating parameter and / or a further operating parameter with one in a preferably non-volatile memory The limit value stored in the logic means is / are compared and, if the limit value should be exceeded or undershot by a predetermined amount, a corrected manipulated variable is determined and output so as not to jeopardize the pump or product quality. In the simplest case, for this purpose, the manipulated variable predetermined by the controller or, based on a preceding comparison, already corrected manipulated variable can be increased or reduced by a predetermined amount, in particular a predetermined factor.

In addition or as an alternative to at least one measured and first actual operating parameter and / or additionally or alternatively to a measured or calculated further actual operating parameter and / or to at least one predefined displacement pump-specific geometry parameter, the first and / or second limit value specification means and / or the first and the second limit value specification means In the calculation of the corresponding limit value or the corrected manipulated variable, a second or second correction means may take into account a delivery fluid parameter (fluid-specific property value / constant) in accordance with a mathematical function or assignment which is stored, for example, in a non-volatile memory of the control means. Prefers can be selected under different fluid parameter data sets manually or automatically, for example, depending on a measurement result. The shear behavior of the conveying fluid is preferably taken into account as the conveying fluid parameter, in particular if a shear gradient is used to determine a limiting value or a corrected actuating variable.

It is particularly expedient if the logic means for determining and / or signaling a maintenance due date of the positive displacement pump are designed as a function of a measured or calculated actual operating parameter and / or as a function of a displacement-pump-specific parameter assigned to the control means. For this purpose, the logic means preferably comprise a corresponding functional unit which takes into account the measured or calculated actual parameter and / or the displacement-pump-specific parameter in determining the maintenance due date. This functional unit preferably calculates the maintenance due date based on a predetermined (functional) assignment. The maintenance due date is preferably signaled via corresponding signaling means, for example a display and / or an LED traffic light, which can emit different color signals.

It is particularly expedient if the first and / or second correction means are designed such that, in the event that the limit value is exceeded or fallen below by a predetermined, in particular very high or very low value, a stop signal for the positive displacement pump motor, in particular emit for a motor contactor, due to which the positive displacement pump motor is stopped, in particular to avoid further endangering the positive displacement pump or other process units or the quality of the conveying fluid.

In a development of the invention, it is advantageously provided that the control means are designed to communicate via a bus system, in particular a CAN bus system, in particular in order to communicate with other positive displacement pump control means and / or a process control system, ie transmit and / or receive data can. It is particularly expedient if in the control module, in particular for communication with the control room and / or at least one further module, a CAN bus system is assigned, which is known mainly from the automotive industry. This bus system is surprisingly found to be particularly reliable and robust in connection with positive displacement pump systems.

It is particularly expedient if the control means are assigned input means, in particular in the form of at least one key, preferably in the form of a plurality of keys and / or a touch screen, etc. in order to be able to configure and / or read out the control means. Particularly preferably, one of a plurality of system parameter data sets and / or delivery fluid parameter data sets stored in a non-volatile memory can be selected via the input means.

An embodiment variant of the control means is particularly expedient, in which the control means have memory means which are designed and controlled to store, in particular also to log, received, calculated and / or transmitted data, in particular measured values or voltage profiles. The memory means are particularly preferably designed and controlled in order to store measured actual operating parameters and / or reference variables and / or manipulated variables and / or corrected manipulated variables.

The system preferably also comprises at least one sensor (sensor means), preferably at least two sensors, which are connected to the control means in signal-conducting fashion, the sensor or the sensors for measuring the first actual operating signal and possibly at least one further actual sensor. Operating signal is formed and arranged. For example, it is a pressure sensor for determining a fluid pressure, in particular a differential pressure and / or a temperature, for example a delivery fluid temperature or a storage temperature. It may also be a tachometer for determining the Verdrängerpumpenzahl and / or a torque meter for detecting the Verdrängerpumpenmotordrehmoments and / or a vibration sensor for measuring a vibration value and / or a fluid viscosity meter for determining the fluid viscosity and / or a Leckageatenmesser and / or Volumetric flow meter act. It is particularly expedient if the control means are signal-connected to the frequency converter in order to receive an actual auxiliary manipulated variable as the first and / or at least one further actual operating parameter, in particular a rotational frequency setpoint or a torque setpoint from the frequency converter.

In a further development of the invention is advantageously provided that the logic of the control module is designed to detect and / or signaling a maintenance need of the pump module, depending on the evaluation of an actual operating parameter, which, if necessary, of the logic in terms of maintenance relevance, in particular is verifiable with the inclusion of a database. It is particularly expedient if the logic is designed or programmed in such a way that a need for maintenance is detected in sufficient time before an intervention actually required in order to be able to determine a period or a period until the recommended implementation of the service implementation. As will be explained later, the maintenance requirement or the recommended period until the maintenance is carried out in the case of providing several control modules of a, so-called master box of the control modules. The communication with this master box can take place, for example, via a bus system, in particular a CAN bus system.

As already indicated above, it is particularly expedient if the control module is associated with a control system for communicating with a control room and / or with a further control module and / or with a sensor module or that the control module is connected to such a bus system. Surprisingly, a known from the automotive industry CAN bus system has been found to be particularly advantageous, reliable and robust in connection with a pump system. The preferred provided sensor module may alternatively communicate via a digital connection and / or analog connection with the control module and / or a control room.

It is particularly useful if a plurality of control modules are connected to the aforementioned bus system, wherein preferably each control module is associated with a displacement pump module and in consequence a drive module.

As also already indicated, it is preferred if one of a plurality of control modules used is designed as a so-called master box, ie has an increased functionality. This is understood to mean that this control module is designed to receive and store data that it receives from other control modules of the system, for example, status information and / or from Systemist parameters (actual operating parameters) and / or speed setpoint signals and / or system setpoint parameters. Preferably, such a master box additionally or alternatively with signaling means, such as a screen, a lights, in particular LED traffic lights, and / or a speaker equipped to communicate with a user or to signal the user an event can, for example a fault and / or the need for maintenance, including, if applicable, a suggested maintenance period until the actual due date of the maintenance.

With regard to the design of the at least one sensor module, there are different possibilities. This can be, for example, as a vibration sensor, in particular for detecting critical oscillations of the pump module and / or with a pressure sensor for detecting an actual pressure and / or as a temperature sensor for determining an actual temperature and / or as a flow rate sensor for detecting an Istdurchflusses and / or as a torque sensor for detecting a torque be formed of the pump module. It is conceivable to combine a plurality of such sensors in a sensor module or to provide separate sensor modules for different sensors. The sensor module signal can for example be fed directly to the control module, or if available via the control room.

It is particularly expedient if a database with system-specific information, in particular pump-module-specific information, is provided in the control module, which can be accessed by the logic of the control module so as to be able to specify a suitable setpoint speed and / or a suitable system setpoint parameter for the controller of the control module ,

The invention also leads to the use of a control module comprising a logic and a controller, in particular a PI or PID controller, for generating a manipulated variable, in particular a speed setpoint signal for a drive unit as a function of at least one system actual parameter and as a function of a reference variable, wherein the reference variable is preferably predetermined by a control room.

Fig. 1:

einen möglichen Aufbau eines Pumpensystems mit zwei Steuermodulen, denen jeweils ein Antriebsmodul und ein Pumpenmodul zugeordnet ist, wobei den beiden Steuermodulen eine fakultative Leitwarte übergeordnet ist,

Fig. 2 bis Fig. 5:

unterschiedliche Ereignisszenerien am Beispiel des Pumpen-Systems gemäß Fig. 1, und

Fig. 6:

eine mögliche Ausgestaltung von als Steuermodul vorliegenden Steuermitteln, die ausgebildet sind, um eine von einem Regler erzeugte Stellgröße mit einem ersten (Pumpenschutz-)Grenzwert zu vergleichen, insbesondere für ein System gemäß den Fig. 1 bis 5,

Fig. 7:

eine alternative Ausgestaltung von als Steuermodul vorliegenden Steuermitteln, die ausgebildet sind um eine vom Regler erzeugte Stellgröße mit einem (Förderfluidschutz-)Grenzwert zu vergleichen, insbesondere für ein System gemäß Fig. 1 bis 5,

Fig. 8.

eine weitere Ausgestaltungsvariante von als Steuermodul vorliegenden Steuermitteln für ein Verdrängerpumpensystem, wie dies beispielhaft in den Fig. 1 bis 5 dargestellt ist, wobei von den Steuermitteln die vom Regler erzeugte Stellgröße mit einem ersten Grenzwert und/oder einem zweiten Grenzwert zu vergleichbar und ggf. korrigierbar ist, und wobei die Vergleichsreihenfolge auch anders, als in Fig. 8 dargestellt, d.h. in umgekehrter Reihenfolge realisiert sein kann,

Fig. 9:

ein NPSH-Diagramm, und

Fig. 10

in einem Diagramm den physikalischen Zusammenhang zwischen dem Förderfluiddruck, gemessen am Druckstutzen der Pumpe, der Förderfluidviskosität (Mediumviskosität) und der Pumpendrehzahl, hier einer Pumpenmindestdrehzahl.

Further advantage, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. These show in:

Fig. 1:

a possible construction of a pump system with two control modules, to each of which a drive module and a pump module is assigned, wherein the two control modules are superordinated to an optional control room,

2 to 5:

different event scenarios using the example of the pump system according to Fig. 1 , and

Fig. 6:

a possible embodiment of the control module present as control module, which are designed to compare a manipulated variable generated by a controller with a first (pump protection) limit, in particular for a system according to the Fig. 1 to 5 .

Fig. 7:

an alternative embodiment of present as a control module control means which are designed to compare a control variable generated by the controller with a (Förderfluidschutz-) limit, in particular for a system according to Fig. 1 to 5 .

Fig. 8.

a further embodiment variant of present as a control module control means for a positive displacement pump system, as exemplified in the Fig. 1 to 5 is represented by the control means, the control variable generated by the controller with a first threshold and / or a second threshold to be comparable and possibly correctable, and wherein the comparison order also different, as in Fig. 8 represented, that can be realized in reverse order,

Fig. 9:

an NPSH diagram, and

Fig. 10

in a diagram, the physical relationship between the delivery fluid pressure, measured at the discharge nozzle of the pump, the delivery fluid viscosity (medium viscosity) and the pump speed, here a minimum pump speed.

In the figures, like elements and elements having the same function are denoted by the same reference numerals.

The displacement pump system 1 shown in the figures comprises a first and a second control module 202, 203, of which the control module (first control module 202) shown on the left in the drawing is equipped as a so-called master box with signaling means 204 in the form of a screen 205 and an LED -Ampel 6.

In contrast to the second control module 203, in addition to the signaling means 204, the first control module 202 (master box) is designed as a data storage unit (data logger) which is connected to the second control module 203 in a signal-conducting manner and transmits data such as actual operating parameters, command values or predefined data Save speeds and preferably with a time code provides. The signaling means 204 are used to signal controls or to display maintenance requirements or time proposals for carrying out the maintenance, which are determined by the first control module 202 and / or the second control module 203 or optionally further, not shown, control modules.

The first control module 202 is associated with a drive module 207, comprising an electric, designed here as an asynchronous motor drive 3 and a frequency converter 4 associated therewith, which is shown separately only for better illustration and preferably arranged directly on the drive motor 3.

The drive module 207, more precisely the drive motor 3 of the drive module 207, is operatively connected via a coupling 210 to a first pump module 211 designed as a screw-type pump.

At the first pump module 211, a sensor module 212 for detecting an actual operating parameter X is arranged, which in the embodiment shown with a vibration sensor is equipped to detect impermissible vibrations, which are then evaluated by the first control module 202, more precisely by integral logic means 7, in particular by comparison with stored in an integral database of the control module 202 information.

As it turned out Fig. 1 results is the first sensor module 212 via a bus system 213, here a CAN bus system, signal-conducting connected to the first control module 202.

In the first control module 202, already mentioned, not shown logic means 7 are integrated and a trained in the embodiment shown as a PID controller, also not shown for clarity, controller 6 for generating a later still to be explained control variable or a corrected manipulated variable for the first frequency which is not formed or alternatively not used or controlled and / or supplied with Systemistparameters is to generate a speed setpoint signal depending on a pressure signal and / or a flow rate signal and / or a vibration sensor signal and / or a temperature sensor signal and / or a torque signal itself.

The first control module 202, like the second control module 203, has a plurality of inputs and outputs which are highlighted in the first control module 202 for better visualization. The first control module 202 includes analog inputs 214, via one of which the first control module 202 is signal-connected to a higher-level control room (command value setting means 8). Via a connection formed here as an analog connection 216, the control room can transmit a command variable W or, alternatively, a control variable, the latter being looped through the first control module 202, for example, and routed to the first frequency converter 4 via one of preferably several analog outputs 217. However, as will be explained later, the first control module 202 is also able to independently generate a manipulated variable, in particular a speed setpoint signal as a function of a reference variable W, an actual operating parameter X and at least one further operating parameter with which the first frequency converter 4 is actuated ,

In addition to the analog inputs 214, there are several digital inputs 218.

In addition, there are several digital outputs 219 via the status signals and other data can be transmitted to the control room.

It can be seen that the first control module 202 not only communicates via the bus system 213 with the sensor module 212 or receives data from it, but is also connected to the second control module 203 via the bus system 213 embodied as a CAN bus system. This includes like the first control module 202 (second) digital outputs 220, (second) digital inputs 221, (second) analog inputs 222 and (second) analog outputs 223 for transmitting a predetermined by the control room or by the second control module 203 in response to a predetermined by the control room Command variable generated control variable to the not shown separately frequency converter of a second drive module 224, which is operatively connected via a second clutch 225 with a second also designed as a positive displacement second pump module 226, to which also a second sensor module 227 is arranged. which communicates via the bus system 213 with the second control module 203.

Via a digital connection 228, the control room (example for reference variable specification means 8) can transmit to the second control module 203 an engine input and an engine output signal, on the basis of which the second control module 203 controls the drive module 224.

Instead of the illustrated sensor modules 212, 227 designed as vibration sensor modules, additionally or alternatively further sensors or sensor modules, each with one or more sensors, may be provided in order to detect a wide variety of systemic parameters in the area of the respective pump module 211, 226.

For reading out and / or programming, a computer 229 may be provided which preferably communicates via the bus system 213 with the control modules 202, 203.

As it turned out Fig. 1 results, the first control module 202 in addition to the signaling means 204 and input means 230 for making, preferably menu-driven inputs. The second control module 203 is in contrast to the first control module 202 not formed as a data storage unit for storing other control modules data and includes in the embodiment shown only a second LED traffic light and no display, with an embodiment is completely feasible without signaling means.

The following are based on the Fig. 2 to 5 different scenarios that may occur during operation of the pump system 1 described.

At the in Fig. 2 In the illustrated scenario, the first drive motor 3 of the first pump module 211 runs at a speed that is generated by the frequency converter on the basis of a speed output by the control module 202. The corresponding or underlying reference variable W is fed via the analog connection 216 into one of the analog inputs 214 of the first control module 202. This determines based on the reference variable W and taking into account an actual operating parameter, a manipulated variable, which is output via an analog output 217 and passed to the first frequency converter 4, which controls the first drive motor 3 according to the manipulated variable. All monitored system actual parameters, in particular a vibration signal determined by the first sensor module 212, which is supplied to the first control module 202 via the bus system 213 are below warning thresholds stored in a database of the logic of the first control module 202. A green LED 231 of the LED traffic light 206 lights up.

At a second, in Fig. 3 visualized scenario reaches an actual operating parameters, here the determined by means of the first sensor module 212 total vibration of the first pump module 211 a first, stored in the aforementioned database of the logic of the first control module 202 warning threshold, with the result that the first logic, the first signaling means 204 such controls that a yellow LED 232 of the first LED traffic light 206 is lit. In addition, a corresponding warning or information is displayed in the screen 205 of the signaling means 204. In the software of the logic of the first control module 2, it is determined that when the first warning threshold is reached, the first pump module 211 is to be driven at a slower speed in order to maintain the permitted maximum vibration values. The logic of the first control module 202 determined in the sequence a corrected downward correcting variable, which then via the analog output 217 the first frequency converter 4 of the first drive module 207th is forwarded. In addition, a corresponding information is output to the control room via one of the digital outputs 219. Depending on the programming, it may also be determined that the control room decides whether the speed setpoint of the control room determined by the actual process or the speed setpoint of the second control module 203 are routed to the frequency converter.

This in Fig. 4 The scenario presented is a sequence of the previously described by Fig. 3 described scenarios. The cause of the increased vibration values has been eliminated. The debugger has been acknowledged at the first control module 202, causing the logic to illuminate the green LED 231 on the first control module 202. In the logic of the second control module 203 in conjunction with the integrated PID controller of the second control module 203 is determined that now the first pump module 202, more precisely its upstream drive motor 3 can continue to operate with the predetermined speed from the control room. In addition, the error is reported by the logic via one of the digital outputs 219 to the control room and the over-tuning of the predetermined speed command signal from the control room is canceled.

At the in Fig. 5 1, a sudden pressure increase on the pressure side is detected or measured via a pressure sensor module 233 and transmitted via an analog connection 234 to one of the analog inputs 214 of the second control module 203. The logic of the second control module 203 recognizes by database alignment exceeding an allowable limit (warning threshold) and causes the flashing of a red LED 235 on the second control module 203. In addition, we transmitted a corresponding information via the bus system 213 to the first control module 202, in which the integral Logic ensures that the control case via a red LED 236 is signaled. In addition, a corresponding message is sent to the control room by the logic of the second control module 203 via a digital output 19. In the logic within the second control module 203 is determined that in the present case, the drive motor 3 is turned off, so that the second pump module takes no damage. Via a digital output 221, the motor contactor is driven accordingly, with the result that the drive motor 208 turns off

The following are based on the Fig. 6 to 8 various embodiments of Verdrängerpumpensystemen described, each having a control module, which is formed as a separate unit, and which is spaced from the drive module and housed in a separate housing. The mode of operation of the control module present as a control module will be explained in detail on the basis of the exemplary embodiments. This mode of operation of the control modules shown can also from the in the Fig. 1 to 5 be implemented control modules.

The basis of the Fig. 1 to 5 in connection with the control modules described there functions can additionally or alternatively also in the in the Fig. 6 to 9 be shown control modules realized.

Embodiment of FIG. 6

In Fig. 6 schematically the construction of a positive displacement pump system 1 is shown. This comprises a in the embodiment shown as a single or multi-spindle pump, in particular three-spindle pump, trained positive displacement pump 2. The positive displacement pump 2 is operatively connected to a motor shaft of a trained as an electric motor displacement pump motor 3, which comprises a frequency converter 4, depending on a generated by a controller 6 Manipulated variable Y _S or a corrected manipulated variable Y ' _S or possibly multiple times corrected manipulated variable Y' _S controls the energization of the motor windings of the positive displacement pump motor 3 and / or regulates. Displacement pump motor and frequency converter form a drive module 207.

To generate the manipulated variable Y _S or a corrected manipulated variable Y ' _S comprises the positive displacement pump 1, for example, formed by a microcontroller control means 5, comprising a previously mentioned controller 6 and logic means 7. The control means 5 are as separate from the drive module 207 control module 202 with its own Housing before.

The control means 5 are preferably preceded by this separate Führungsgrößenvorgabemittel 8, for example, a process control, which provide the control means 5 with a reference variable W, for example, a nominal volume flow or a desired pressure representing electrical voltage signal.

The reference variable W and an externally supplied first actual operating parameter X are supplied to the controller 6, more precisely to a difference former 9 of the controller 6, which calculates the difference XW. The actual controller 6, which is designed, for example, as a PI or PID controller, thus determines a manipulated variable Y _S on the basis of the reference variable W and the first actual operating parameter X measured here _. This is not fed directly to the frequency converter 4 as in the prior art. but first passes through logic means 7. These comprise in the embodiment shown first comparison means 10 which compare the manipulated variable Y _S generated by the controller 6 with at least a first limit, preferably a maximum to be observed first limit Y _Grenzmax and / or a minimum to be observed limit Y _Grenzmin . Instead of a direct comparison of the manipulated variable Y _S with the at least one first limit value, a comparison value standing in a functional relationship with the manipulated variable Y _S can be calculated in the calculation thereof according to a (not) shown (optional) comparison value specification means on the basis of the manipulated variable Y _s functional relationship and at least one actual operating parameters, for example, the first actual operating parameters X and at least one further, to be explained later further actual operating parameters can be incorporated. Also, the comparison value specification means may, according to a functional relationship for calculating the comparison value, take into account at least one geometry parameter of the positive displacement pump and / or a delivery fluid parameter, which must then also be taken into account when taking into account the limit value. In the exemplary embodiment shown, however, this additional comparison value _{calculation step} is saved and the manipulated variable Y _{S is} compared directly with at least one first limit value Y limit _max and / or Y limit value, wherein the at least one first limit value represents a positive displacement pump protection limit whose exceeding or _{falling below} a defect the positive displacement pump has or could have.

The comparison means 10 is associated with a first functional unit 11, which includes first correction means 13 in addition to first limit value specification means 12. The functional unit 11 calculates the at least one first limit value Y _Grenzmax , Y _Grenzmin of the comparison means 10 is supplied in addition to the manipulated variable Y _S generated by the controller 6. The comparison means now check whether the manipulated variable Y _{S falls} below a maximum first limit value Y _Grenzmax and / or whether the manipulated variable Y _{S has} a minimum first value Limit Y _exceeds limit. If this is the case, the manipulated variable Y _S is a permissible control variable which does not endanger the positive-displacement pump, which can be supplied to further comparisons and correction routines, not shown, or as shown directly as input signal to the frequency converter 4 of the positive-displacement pump motor 3 on this basis controls.

To calculate the at least one first limit value, the first actual operating unit 11 is supplied with the first actual operating parameter X and another measured or calculated actual operating parameter Y _H and / or X _H , wherein the actual operating parameter Y _H in the exemplary embodiment shown is an auxiliary manipulated variable of the frequency converter, for example, a rotational frequency setpoint or a torque setpoint of the frequency converter. These are not measured values, but based on at least one actual parameter, for example based on a current control measurement calculated by the frequency converter, in particular simulated values. In the exemplary embodiment shown, the further actual operating parameter X _H is an auxiliary control variable, for example an engine and / or positive displacement pump speed or a torque, which are preferably measured directly on the engine 3. In any case, therefore, of the first limit value specification means 12 for calculating the at least one pump protection limit value, an operating parameter, for example the first actual operating parameter, here the actual value of the controlled variable from the process control path 14 is considered and at least one further actual operating parameter Y _H , X _H or a, preferably measured Hauptstellgröße Y _HH for the process control variable X, for example, a pressure or a flow.

In the event that an exceeding of the maximum first limit value Y _Grenzmax and / or a falling below the minimum first limit value Y _Grenzmin is detected by the comparison means, this is reported to the first function unit 11, the first correction means 13 then a corrected manipulated variable Y _'S determine taking into account the first actual operating parameter X and one of the aforementioned further actual operating parameters Y _H , X _H , Y _HH . This corrected manipulated variable Y ' _S can then, as shown, be fed to the comparison means as an input variable for comparison with a first limit value Y _Grenzmax and / or Y _Grenzmin or bypassing the Comparison means (not shown) a further comparison and correction procedure or directly the frequency converter 4 as an input signal.

From a preferably non-volatile memory 19, specific geometry parameters GP and / or conveying fluid parameters FP specific to the conveying fluid, such as the shear behavior of the conveying fluid, can be supplied to the first limiting value specification means 12 and / or the first correction means 13 for the positive displacement pump assigned to the control means 5, which, in the context of a functional relationship, find their way into the calculation of the first limit values Y limit _max , Y _{limit min} , and / or the corrected manipulated variable Y ' _S.

In the exemplary embodiment shown, the corrected manipulated variable Y ' _S is the maximum or minimum permissible first limit value Y _Grenzmax , Y _Grenzmin , as close as possible to the manipulated variable Y _S generated by the controller. In this respect, the first limit value specification means 12 and the first correction means 13 include a common computer (computer means), since the corrected manipulated variable Y ' _S in the embodiment shown corresponds to a first limit value Y limit _max , Y _{limit min} . The manipulated variable Y _S generated by the controller is overwritten with the corrected manipulated variable Y ' _S.

In particular, if the corrected manipulated variable Y ' _{S is} not to correspond to the first limit value, the first correction means 13 and the first limit value specification means 12 can be realized completely separately, ie with separate calculation means, ie in separate functional units. Naturally, this is also possible for the case described above in that the corrected manipulated variable Y ' _S should correspond to a first limit value, in which case, as in Fig. 1 shown limit value setting means 12 and correction means 13 merge together, so have a common calculation routine.

In the following, the embodiment according to Fig. 1 described by way of exemplary, non-limiting specific embodiments.

First example

The first actual operating parameter X corresponds to the actual controlled variable, in the exemplary embodiment shown a pressure, measured in bar. It is assumed that the reference variable X is a pressure and is initially 20 bar. Likewise, the actual operating parameter X is measured as 20 bar.

Now a command value change takes place. The reference variable X changes, for example, by a corresponding specification from 20 bar to 10 bar. This results in a control deviation W-X = 10 bar.

The controller 6 determines a new manipulated variable Y _S , in this case a speed-proportional voltage value, which is significantly smaller than in a previous run or in a previous calculation. The first threshold value _{setting means} 12 calculates a minimum allowable limit value Y limit _min. This represents in the embodiment shown a minimum allowable speed. Maintaining a minimum permissible speed is desirable in order to avoid the risk of lubricant leakage when this minimum permissible speed is exceeded.

The minimum permissible speed, ie the minimum permissible limit Y limit _min is calculated based on the following functional relationship: $${\mathrm{Y}}_{\mathrm{Grenzmin}}={\mathrm{n}}_{\mathrm{permissible}}={\left(\frac{X}{k*b*c*v^a}\right)}^2$$

In the functional context, Y _Grenzmax corresponds to the minimum permissible limit value. This is a minimum permissible speed (n _permissible ).

The first actual operating parameter X is in this case the measured controlled variable, here the new actual pressure of 10 bar. The factor ^• α is a further operating parameters, namely a measure for the, in particular via a temperature measurement of the conveying fluid certain operating viscosity of the fluid or for the situation influence of viscosity on the maximum allowable pressure. This value is 10 ^0.32 for the particular medium in the embodiment shown. The constant k is the correction value for the lubricity of the medium, this is exemplified by 0.75 for the particular medium.

The constant b is a correction value for the tribocharging capability of the pump casing. This is in the illustrated embodiment 1. The pump-specific characteristic c is a characteristic value for the radially loaded rotor diameter. This is for example in the embodiment shown 0.55.

The minimum permissible limit value Y _Grenzmin is supplied to the first comparison means 10 which compare the manipulated variable Y _S determined by the controller 6 with this. Depending on the comparison, either the manipulated variable Y _S determined by the controller is transmitted to the frequency converter or a corrected manipulated variable Y ' _{S is} determined by the first correction means, which preferably corresponds to the previously calculated (or newly calculated) minimum permissible limit value Y limit _min .

Second example

The first actual operating parameter X corresponds to the actual controlled variable, here a pressure. An actual pressure of 20 bar is measured. Due to an appropriate default, the setpoint of the controlled variable, i. the reference variable W from 20 to 30 bar. At the same time there is a change in the disturbance variable. It is believed that the flow resistance increases due to a smaller flow area, i. a smaller Durchströmdurchmessers, for example, as a result of a tool change.

In practice, this results in the actual operating quantity X, i. the actual pressure will clearly exceed the reference variable W, or would, since initially with still unchanged speed is promoted and but in the meantime the flow resistance has increased significantly due to the tool change.

The resulting control deviation at the subtractor output then leads to a significant withdrawal, ie reduction of the manipulated variable Y _S. In the event that this uncorrected transmitted to the frequency converter 4 as a target value, this would result in a risk to the pump with respect to the allowable pressure at a reduced low speed. To prevent this, the aforementioned manipulated variable Ys is the minimum limit for refracting Y _Grenzmin (first threshold value) which represents the minimum allowable speed. The calculation is based on the functional relationship specified in the first embodiment. Since the manipulated variable Y _{S falls below} the minimum permissible limit value Y limit value, ie the minimum permissible speed, the first correction means 13 output a corrected manipulated variable Y ' _S , which is transmitted to the frequency converter instead of the manipulated variable Y _S.

The corrected manipulated variable Y ' _S preferably corresponds to the calculated minimum permissible limit value Y limit _min .

Third example

wobei von der Pumpen-Baugröße über den Spindeldurchmesser d_a und dem Spindelsteigungswinkel auf die für eine bestimmte Baugröße und bestimmten Steigungswinkel gültige Axialgeschwinigkeit des Mediums innerhalb der Pumpe geschlossen werden kann, so dass vereinfacht folgender Zusammenhang besteht: $$\mathit{NPSH}=f\left(v_{ax\mathrm{}BG\mathrm{}\mathit{Stgg}},Viskosität\mathrm{}v,Drehzahl\mathrm{}n\right)$$

Folglich ist $${\mathrm{v}}_{{\mathrm{ax\; zul}}_{{\mathrm{BG}}_{\mathrm{NPSH}}}}=\mathrm{f}\left(v,\mathrm{n}\right)$$

so dass über den Zusammenhang $$v_{\mathit{ax}}=S\ast n\mathrm{bzw}.\mathrm{}n=\frac{v_{\mathit{ax}}}{S}$$

schließlich der Zusammenhang $$Y_{\mathit{Gren}{z}_{\max }}=n_{\mathit{zu}{l}_{B{G}_{\mathit{NPSH}}}}=\frac{v_{a{x}_{\mathit{zu}{l}_{B{G}_{\mathit{NPSH}}}}}}{S}$$

hergestellt werden kann.The reference variable W is a volume flow measured in l / min. The first actual operating parameter X is a measured volume flow. It is assumed that the volumetric flow demand increases during operation. In the example shown, the reference value is to double, namely from 1500 l / min to 3000 l / min. From the resulting control deviation WX, the controller 6 determines a manipulated variable Y _S , here a speed. This manipulated variable Y _S , ie the speed specified by the controller 6 is compared by the comparison means 10 with a maximum permissible speed, ie a first limit value Y _Grenzmax . This maximum permissible speed is determined based on the NPSH _available , ie based on the existing NPSH or the holding pressure level of the system. In the exemplary embodiment shown, this amounts to 8 mWs (meter of water column). Based on the NPSH _available and another, measured actual operating parameter, here the viscosity of the medium, Y _Grenzmax , ie the maximum permissible speed is determined. This is done by way of example with reference to the in Fig. 4 or, alternatively, polynomials stored in a non-volatile memory based on the following calculation basis: $$\mathit{NPSH}=f\left(\mathit{pump}-BauGröße\mathrm{}\left(d_a\right).\mathit{Spindle\; pitch\; angle}.ViskOsität\mathrm{}v.DreHzaHl\mathrm{}n\right)$$

it being possible to infer from the pump size via the spindle diameter d _a and the spindle pitch angle to the axial velocity of the medium within the pump which is valid for a specific size and specific pitch angle, so that the following is simplified: $$\mathit{NPSH}=f\left(v_{ax\mathrm{}BG\mathrm{}\mathit{StGG}}.ViskOsität\mathrm{}v.DreHzaHl\mathrm{}n\right)$$

Consequently, it is $${\mathrm{v}}_{{\mathrm{ax\; zul}}_{{\mathrm{BG}}_{\mathrm{NPSH}}}}=\mathrm{f}\left(v.\mathrm{n}\right)$$

so that about the context $$v_{\mathit{ax}}=S*n\mathrm{respectively},\mathrm{}n=\frac{v_{\mathit{ax}}}{S}$$

finally, the context $$Y_{\mathit{Gren}{z}_{\mathrm{Max}}}=n_{\mathit{to}{l}_{B{G}_{\mathit{NPSH}}}}=\frac{v_{a{x}_{\mathit{to}{l}_{B{G}_{\mathit{NPSH}}}}}}{S}$$

can be produced.

Thus, for a pump with a certain pump size, with a certain spindle pitch angle and a certain NPSH value, an allowable pump speed n _{zul BG NPSH} be calculated.

In the diagram according to Fig. 4 is indicated on the left vertical axis of the NPSH in meters of water (mWs). On the right vertical axis, the speed is given in revolutions per minute. On the horizontal axis, the axial velocity of the fluid is given in m / s. The diagram refers to an exemplary pump with a size 20 and a lead angle of the spindle of 56 °. The linearly rising line characterizes the axial velocity v _{ax of} the medium (delivery fluid) as a function of the rotational speed.

To determine the first limit value Y _Grenzmax , ie the maximum permissible rotational speed, it is necessary to move to the right in the diagram, starting from an NPSH of 8 mWs, up to the characteristic value of 500 mm ² / s for the measured viscosity Curve. At the intersection with this curve, the diagram must move up to the linear line. At the intersection with this line, the maximum permissible speed, ie the first limit value Y _Grenzmax, can _then be read on the right vertical axis. This is about 3800 revolutions / min for the measured viscosity, ie the other actual operating parameters.

As mentioned above, the reference variable, ie the required volume flow doubles, which is 3000 l / min due to the linear relationship between a manipulated variable change from the assumed 1500 rpm. Since this manipulated variable Y _S of 3000 1 / min is smaller than the first limit Y _Grenzmax of about 3800 1 / min, the manipulated variable Y _S can be transmitted to the frequency converter 4 as an input.

If the _reference variable would not only double but triple, for example, this would result in a manipulated variable of 4500 1 / minute, which would be greater than the first limit value Y limit value, so that the correction means 13 will correct the manipulated variable Y _S given by the controller 6 by a corrected manipulated variable Y ' _S , which corresponds to, for example, the first limit, ie 3800 1 / min in the present example.

Embodiment of FIG. 7

The embodiment according to Fig. 7 differs from the embodiment according to Fig. 6 merely in that the manipulated variable Y _S generated by the controller 6 is not compared with at least one first limit value assuring or representing the positive displacement pump protection, but with at least one second limit value ensuring the delivery fluid quality. In the exemplary embodiment shown, this is a second limit value. Also at Fig. 7 The control means are present as separate from the drive module control module.

The at least one second limit value Y _Grenzmax , Y _Grenzmin ensures compliance with the delivery _{fluid quality} . In the exemplary embodiment shown, only a single, maximum second limit value Y _{limit-max is} provided by second limit value specification means 15, wherein, alternatively, a plurality of second limit values, eg an additional one minimum limit Y limit _min , which can be calculated to ensure the _{conveyed fluid quality} .

If compare each second comparison means 16 determines whether the manipulated variable generated by the controller 6 Y _S or a corrected already in a preceding, not included here further correction procedure manipulated variable exceeds the second threshold value Y _Grenzmin by a certain amount. If the manipulated variable Y _{S is} less than or equal to the maximum limit value, the manipulated variable Y _S generated by the controller 6 or supplied to the comparison means 16 is made available (calculated) to the frequency converter 4.

Otherwise, with the aid of second correction means 18 included in a second functional unit 17 in addition to the second limit value specification means 15, a corrected manipulated variable Y ' _{S is} provided with which the manipulated variable Y _{S is} overwritten. To calculate the at least one second limit value Y limit value, the second limit value _{specification} means 15 take into account the first actual operating parameter X and at least one further (other) actual operating parameter, for example an auxiliary _{manipulated variable} Y _H , an auxiliary controlled variable X _H and / or a skin _{manipulated variable YHH} . It can also be realized that, in addition, geometry parameters GP of the displacement pump and / or delivery fluid parameters FP, as well as the vibration, are taken into account in the calculation.

Fourth example

The fourth example concerns the protection of the medium, i. The second limit value is determined such that the manipulated variable does not result in a negative impairment of a quality parameter of the delivery fluid (delivery medium) conveyed by the positive displacement pump.

In the specific example, it should be ensured that the pumped medium is not sheared unduly. The maximum permissible shear rate of the medium is therefore included in the calculation of the second limit value. It should again be realized a speed control, so that the second limit corresponds to a maximum permissible speed. This means that the first operating parameter X is a volume flow of the process line. In addition to the medium-specific limit of the maximum permissible shear rate, the determination of the second limit value includes functional conditions of the pump, ie speed ratios are taken into account, namely the angular velocity difference of the rotating positive displacement rotors (spindles) relative to the stationary pump housing. The velocity ratios in the columns are directly proportional to the pump speed and there is an inversely directly proportional relationship to the size of the function gap, ie the actual linear shear rate. This functional gap is dependent on pump-specific conditions, namely on the actual radial gap, ie on the firmly set pump rotor radial clearance and also on current operating conditions, namely the current pressure load of the delivery fluid, as well as the current viscosity of the delivery fluid. The latter two further actual operating parameters are measured and are taken into account in the calculation of the second limit value Y _Grenzmax , ie in the calculation of the maximum permissible rotational speed.

For example, a delivery fluid having a dynamic viscosity η of 5 Pas is delivered. This corresponds to a kinematic viscosity v of 5000 mm ² / s, wherein, assuming a density ρ of 1000 kg / m ³ while maintaining a maximum allowable shear stress τ of 100000 N / m ^2, a maximum allowable shear rate D _zul of 20,000 1 / sec for the delivery fluid in a given pump. This is characterized by a rotor diameter of D _a = 70 mm and by a differential pressure-dependent radial gap S = h ₀ , which gives a value of 0.021 mm at Δp = 5 bar. This results in a maximum permissible speed, ie a second limit Y _{limit max} of 191 1 / min. As long as the preset of the regulator 6 manipulated variable Y _S is below the aforementioned value, the manipulated variable Y is _S can be passed directly to the inverter 4 - otherwise, the manipulated variable Y is _S by a will of the second correction means 18 corrected or limited manipulated variable Y _"S overwritten ,

• Aus
• z.B. τ_zul = D * η und η = v * ρ für newtonsche Flüssigkeiten
• folgt $$D_{\mathit{zul}}=\frac{{\tau }_{\mathit{zul}}}{v\ast \rho }$$
  
• Des Weiteren gilt $$n_{\mathit{zul}}=\frac{W_{\mathit{zul}}}{D_a\ast \pi \ast 60}$$
  
• Mit Einsetzen in $$W_{\mathit{zul}}=D_{\mathit{zul}}\ast S\mathrm{bzw}.\mathrm{in}{D}_{\mathit{zul}}=\frac{\mathrm{\Delta }{W}_{\mathit{zul}}}{S}$$
  
• kann unter Zusammenfassung aller vorkommenden Konstanten zu k die maximal zulässige Drehzahl berechnet werden: $$D_{\mathit{zul}}=\frac{D_a\ast \pi \ast n}{k\ast S}\to n_{\mathit{zul}}=\frac{D_{\mathit{zul}}\ast k\ast S}{D_a\ast \pi }$$
  

The example described above is based on the following calculation principles:

• Out
• eg τ _zul = D * η and η = v * ρ for Newtonian fluids
• follows $$D_{\mathit{zul}}=\frac{{\tau }_{\mathit{zul}}}{v*\rho }$$
  
• Furthermore, applies $$n_{\mathit{zul}}=\frac{W_{\mathit{zul}}}{D_a*\pi *60}$$
  
• With insertion in $$W_{\mathit{zul}}=D_{\mathit{zul}}*S\mathrm{respectively},\mathrm{in}{D}_{\mathit{zul}}=\frac{\mathrm{\Delta }{W}_{\mathit{zul}}}{S}$$
  
• can be calculated by summing all occurring constants to k the maximum allowable speed: $$D_{\mathit{zul}}=\frac{D_a*\pi *n}{k*S}\to n_{\mathit{zul}}=\frac{D_{\mathit{zul}}*k*S}{D_a*\pi }$$
  

The maximum permissible speed therefore corresponds to the limit value Y _Grenzmax.

In the event that the conveying fluid (medium) to be pumped does not exhibit Newtonian behavior, the Reynolds numbers in the pump function gap, the shear rate and the resulting shear, would have to be calculated, for example, for pseudoplastic conveying fluids representative viscosities are calculated according to known physical relationships. In this way, in the same way as in the case of Newtonian conveying fluids, the permissible conditions for these fluids can be monitored and maintained.

Embodiment of FIG. 8

The embodiment according to Fig. 8 combines the embodiments according to the Fig. 6 and Fig. 7 ie, the control means 5 are designed in such a way that the manipulated variable Y _S output by the controller 6 can be compared both with at least one first limit value (pump protection limit value) and with at least one second limit value (medium protection limit value). In the embodiment shown according to Fig. 3 the control variable Y _S generated by the controller 6 is first compared with a first and then with a second threshold, wherein the reverse arrangement is of course feasible, ie, that is compared first with a second and then with a first limit.

It is according to the embodiment Fig. 8 characterized in that the output value of the first comparison forms the input variable for the second comparison, wherein the output variable of the first comparison can be the uncorrected manipulated variable Y _S , namely if there is no limit value overshoot or undershoot in the first comparison and Y _{s is} thus not corrected or, alternatively, by a manipulated variable Y ' _S corrected by the first comparison means 10.

Y _S or Y ' _S are then the input variables for the second comparison means 16. If no correction is made here, the input value for the second comparison Y _S or Y' _{S is sent} to the frequency converter 4 or in the case of a correction the corrected manipulated variable Y " _S.

In the exemplary embodiment shown, first and second decision-making means 20, 21 are provided in which it is determined whether a pump protection comparison or a medium protection comparison is to be carried out. The respective decision can for example be specified by software, so that the user alternatively only one Pump protection comparison or a medium protection comparison can realize, or both comparison operations.

Embodiment of FIG. 10th

This exemplary embodiment represents a preferred embodiment for realizing the pump protection. The manipulated variable is a speed signal for the pump, the pump speed being plotted in the diagram on the left vertical axis. As the first actual operating parameter, the delivery pressure, measured at the discharge nozzle of the pump, flows into the calculation of the first limit value, the delivery fluid pressure being plotted on the right vertical axis. The delivery fluid viscosity (medium viscosity) flows into the calculation of the first limit value as a further actual operating parameter, the medium viscosity being plotted on the horizontal lower axis. As a guide variables come here alternatively the delivery fluid volume flow or the pump speed or the delivery fluid pressure into consideration. In the specific embodiment, it is assumed that the delivery fluid pressure is the reference variable.

In the embodiment shown, it is assumed that the conveying fluid viscosity (medium viscosity) due to a corresponding medium change from 12mm ^{2 /} s to 9 mm ² / s, to 6 mm ² / s, to 4 mm ^{2 /} s and then (stepwise) up to 2mm ^{2 /} s drops. The delivery fluid volume flow may fluctuate. The reference variable, ie the process pressure (delivery fluid pressure) should initially be kept at 10bar, then 20bar, etc., ie incrementally by 10bar each up to a maximum of 50bar. In other words, the reference variable will gradually change from 10bar to 50bar. The controller outputs a manipulated variable (Y _S ) as a function of the reference variable (W). The first limit value _{specification means} calculate a first limit value, in the present case a minimum _{rotational speed} Y _{limit min} as a function of the first actual operating parameter, here the delivery fluid pressure and the further actual operating parameter, here the medium viscosity, wherein in the concrete exemplary embodiment the medium viscosity is determined indirectly via the delivery fluid temperature. In the present Ausführunsbeispiel falling below the first limit, ie the minimum speed would cause a defect state of the positive displacement pump. The comparison means compare in the specific embodiment of the controller predetermined manipulated variable, ie, a speed signal with the first limit value calculated by the first threshold value setting means. If the manipulated variable in the illustrated embodiment is above this first limit value, the manipulated variable is forwarded to the frequency converter as an input signal. If the manipulated variable undershoots the first limit value, a corrected manipulated variable is determined or determined as an input signal in the embodiment shown and passed on to the frequency converter as a corrected manipulated variable in the embodiment shown by the first correction means passing on the first limit value determined by the limit value specification means.

LIST OF REFERENCE NUMBERS

1

positive displacement pump

2

Positive displacement pump or positive displacement pump module

3

Verdrängerpumpenmotor

4

frequency converter

5

control means

6

regulator

7

logic means

8th

Command value specification means, in particular control room

9

Difference pictures of the controller

10

first comparison means

11

first functional unit

12

first threshold value specification means

13

first correction means

14

Process control system

15

second threshold value setting means

16

second comparison means

17

second functional unit

18

second correction means

19

Storage

20

first decision-making tool

21

second decision-making means

202

first control module

203

second control module

204

first signaling means

205

screen

206

LED Traffic Light

207

drive module

210

clutch

211

first pump module

212

first sensor module

213

bus system

214

analog inputs

216

analog connection

217

analog output

218

Digital inputs

219

Digital outputs

220

second digital outputs

221

second digital inputs

222

second analog inputs

223

second analogue outputs

224

second drive module, sensor module

225

second clutch

226

second pump module

227

second sensor module

228

Digital connection

229

computer

230

input means

231

green LED

232

yellow LED

233

Pressure sensor module

234

Digital connection or analog connection

235

red LED

236

red LED

Y _s

manipulated variable

Y _S '

corrected manipulated variable

Y _S "

corrected manipulated variable

X

first actual operating parameter (preferably actual controlled variable)

_YHH

further actual operating parameter (main control variable)

Y is _H

further actual operating parameter (auxiliary manipulated variable)

X _H

further actual operating parameter (auxiliary control variable)

W

command variable

GP

Geometry parameter of the positive displacement pump

FP

Conveying fluid parameters

Claims (16)

1. Displacement pump system, having:

   - a displacement pump module (2; 211; 226), preferably a screw pump, and

   - a replaceable drive module (207) that is separate from the displacement pump module (2; 211; 226) and has an electric drive motor (3) and a frequency converter (4) assigned thereto for regulating or setting a drive motor speed, and

   - control means (5) having a controller (6) for creating a manipulated variable (Ys) for the frequency converter (4) depending on a reference variable (W) and a first actual operating parameter (X), and logic means (7) assigned to the controller (6)

   - reference variable setting means (8) for providing the reference variable (W) for the control means (5), wherein
   the control means (5) are provided in a control module (202, 203) that is separate from the drive module (207), and
   the drive module (207) is replaceable separately from the control module (202, 2033), and
   the drive module (207) has no controllers configured and/or activated for generating a manipulated variable (Y_s),
   characterized in
   that different system parameter data records for various displacement pumps (2) and/or different conveyed fluid parameters (FP), in particular ones that are selectable via a selection menu, are stored, preferably manually, in a nonvolatile memory (19), in particular an EEPROM of the control means (5).
2. System according to Claim 1,
   characterized in
   that the logic means (7) have first limit value setting means (12) which are designed to determine at least one first limit value (Y_Grenzmax, Y_Grenzmin) depending on the first actual operating parameter (X), in particular the conveyed fluid pressure, and at least one additional actual operating parameter (X_H, Y_H, Y_HH), which, if exceeded or undershot, could result in a defect state of the displacement pump (2), and
   which have first comparison means (10) that are configured to compare the manipulated variable (Y_s), or a corrected manipulated variable (Y'_s, Y"_s), or a comparison value determined according to a functional relationship from the manipulated variable (Y_s) or the corrected manipulated variable (Y'_s, Y"_s) to the at least one limit value (Y_Grenzmax, Y_Grenzmin), and
   which have first correction means (13) that are configured in order to output - in the event that the first comparison means (10) detect an exceeding of or an undershooting of the at least one first limit value (Y_Grenzmax, Y_Grenzmin) by a certain degree - a corrected manipulated variable (Y'_s, Y"_s) which corresponds to limit value (Y_Grenzmax, Y_Grenzmin) determined by the limit value setting means (12).
3. System according to Claim 1,
   characterized in
   that the logic means (7) have the second limit value setting means (15), which are configured to determine at least one second limit value (Y_Grenzmax, Y_Grenzmin) depending on the first actual operating parameter (X), and at least one additional actual operating parameter (X_H, Y_H, Y_HH), in particular of the conveyed fluid viscosity, which, if exceeded or undershot, could have a negative impact on the quality parameter of the delivery fluid that was delivered with the displacement pump (2), and
   which have second comparison means (16) that are configured to compare the manipulated variable (Y_s), or a corrected manipulated variable (Y'_s, Y"_s), or a comparison value determined according to a functional relationship from the manipulated variable (Y_s) or the corrected manipulated variable (Y'_s, Y"_s) to the at least one second limit value (Y_Grenzmax, Y_Grenzmin), and
   which has second correction means (18) that are configured to output - in the event that the second comparison means (16) detect an exceeding or undershooting of the at least one second limit value (Y_Grenzmax, Y_Grenzmin) by a certain degree - a corrected manipulated variable (Y'_s, Y"_s) that preferably corresponds to a limit value (Y_Grenzmax, Y_Grenzmin) determined by the second limit value setting means (15).
4. System according to Claim 2 or 3,
   characterized in
   that the first actual operating parameter is a measured actual controlled variable (X), in particular an actual pressure, an actual pressure difference, or an actual volumetric flow of the conveyed fluid.
5. System according to any of Claims 2 to 4,
   characterized in
   that the at least one additional actual operating parameter is a measured actual controlled variable (X), in particular an actual pressure, an actual pressure difference or an actual volumetric flow of the conveyed fluid, and/or that the at least one additional actual operating parameter is an auxiliary manipulated variable (Y_H) which is measured or calculated on an actual value basis, in particular a rotational frequency target value of the frequency converter (4) or a torque target value of the frequency converter (4), and/or that the at least one additional operating parameter is an auxiliary manipulated variable (Y_H) that is measured or calculated on the basis of an actual value, in particular a speed of the displacement pump motor (3) or a torque of the displacement pump motor (3), and/or that the at least one additional actual operating parameter is a measured temperature, in particular a conveyed fluid temperature or a storage temperature of the displacement pump (2), and/or that the at least on additional operating parameter is a measured vibration value, and/or that the at least one additional actual operating parameter is a conveyed fluid viscosity that is measured or calculated, and/or that the at least one additional actual operating parameter is a measured leakage rate.
6. System according to any of Claims 2 to 5,
   characterized in
   that the logic means (7) comprise at least one comparison value determination means which is configured to determine the comparison value on the basis of a functional relationship from the manipulated variable (Ys), or from the corrected manipulated variable (Y'_s, Y"_s), and/or from the first and the at least one additional actual operating parameter (X_H, Y_H, Y_HH).
7. System according to Claim 6,
   characterized in
   that the comparison value determination means are configured in such a way that, for the determination of the comparison value within the context of the functional relationship, they take into account at least one geometric parameter (GP) stored in a memory (19) that is specific for the displacement pump (2) assigned to the control means (5), preferably a gap width or a spindle diameter, and/or from a conveyed fluid parameter (FP) stored in a memory (19), in particular the shear behavior of the conveyed fluid.
8. System according to any of Claims 2 to 7,
   characterized in
   that the first and/or the second limit value setting means are configured determining the first or second limit value as a function of at least one geometric parameter (GP) stored in a memory (19) which is specific for the displacement pump (2) assigned to the control means (5), preferably a gap width or a spindle diameter, and/or as a function of a conveyed fluid parameter (FP) stored in a memory (19), in particular the shear behavior of the conveyed fluid.
9. System according to any of Claims 2 to 8,
   characterized in
   that the first and/or the second correction means are configured determining the corrected manipulated variable (Y'_s, Y"_s) as a function of at least one geometric parameter (GP) stored in a memory (19) which is specific for the displacement pump (2) assigned to the control means (5), a gap width or a spindle diameter, and/or as a function of a conveyed fluid parameter (FP) stored in a memory (19), in particular the shear behavior of the conveyed fluid.
10. System according to any of Claims 2 to 9,
    characterized in
    that the first and/or the second limit value setting means are configured determining the first or the second limit value as a function of a minimum or maximum shearing rate in the displacement pump (2) stored in a memory (19) which is specific for the displacement pump (2) assigned to the control means (5), and/or as a function of the actual shearing rate, and/or that the first and/or second correction means are configured determining the corrected manipulated variable (Y'_s, Y"_s) as a function of at least one shearing rate in the displacement pump (2) stored in a memory (19) which is specific for the displacement pump (2) assigned to the control means (5), and/or as a function of the actual shearing rate.
11. System according to any of Claims 2 to 10,
    characterized in
    that the first and/or the second comparison means are configured to compare the first actual operating parameter (X), and/or the at least one additional actual operating parameter (X_H, Y_H, Y_HH), and/or a value calculated according to a functional relationship from the first actual operating parameter (X), and/or from the at least one additional actual operating parameter (X_H, Y_H, Y_HH), or a manipulated variable (Y_s) of the controller (6), or a corrected manipulated variable or a comparison value calculated on the basis of the manipulated variable (Y_s), or the corrected manipulated variable (Y'_s, Y"_s) to at least one limit value stored in a memory (19) of the logic means (7), and that the first or second correction means are configured to output a corrected manipulated variable (Y'_s, Y"_s) in the event that the first comparison means detect an exceeding or an undershooting of the at least one set limit value.
12. System according to any of the preceding claims,
    characterized in
    that the logic means (7) for determining and/or signaling when a servicing of the displacement pump (2) is required are configured depending on the first actual operating parameter (X), and/or at least one additional actual operating parameter (X_H, Y_H, Y_HH), and/or a parameter which is specific for the displacement pump (2) assigned to the control means (5).
13. System according to any of the preceding claims,
    characterized in
    that the control means (5) have storage means that are configured and activated in order to save the first actual operating parameter (X), and/or the at least one additional operating parameter (X_H, Y_H, Y_HH), and/or the reference variables (W), and/or the comparison values, and/or the limit values, preferably each with a time stamp.
14. System according to any of the preceding claims,
    characterized in
    that the control means (5) along with the process monitoring system and/or plurality of control means (5) are configured to communicate with each other via a bus system, in particular a CAN bus system.
15. System according to any of the preceding claims,
    characterized in
    that the control means (5) are connected in a signal-conducting manner to at least one sensor for the reception of the first actual operating parameter (X) and/or the at least one additional measured actual operating parameter (X_H, Y_H, Y_HH), and/or that the control means (5) is connected in a signal-conducting manner to the frequency converter (4) for the reception of the first actual operating parameter (X) and/or the at least one additional measured actual operating parameter (X_H, Y_H, Y_HH), in particular a displacement pump motor speed, and/or a rotational frequency target value of the frequency converter (4), and/or a rotational frequency target value of the frequency converter (4).
16. System according to any of the preceding claims,
    characterized in
    that a plurality of control modules (202, 203) connected to the bus system (213) are provided, each of which is assigned to a drive module (207) and a pump module (2, 21 1,226).

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