DRIVE PROTECTION AND MANAGEMENT METHOD OF A PRESSURIZATION SYSTEM

Abstract

The disclosure relates to a drive protection and management method of a pressurization system comprising at least two operatively independent hydraulic pumps, the method including setting a plurality of predetermined parameters by a user by means of an electronic control unit at each of the hydraulic pumps, detecting at least one pressure value by means of at least one pressure sensor at a delivery duct of each of the hydraulic pumps, determining a drive in a sequential and/or synchronized manner of the at least two hydraulic pumps by managing and interpolating, independently for each pump, these predetermined parameters and the at least one pressure value at each of the hydraulic pumps by means of each electronic control unit. The disclosure relates to a pressurization system as well, adapted to implement this method.

Claims

1. Drive protection and management method of a pressurization system comprising at least two operatively independent hydraulic pumps, said method comprising: setting a plurality of predetermined parameters by a user by means of an electronic control unit at each of said hydraulic pumps; detecting at least one pressure value by means of at least one pressure sensor at a delivery duct of each of said hydraulic pumps; determining a drive in a sequential and/or synchronized manner of said at least two hydraulic pumps by managing and interpolating said predetermined parameters and said at least one pressure value at each of said hydraulic pumps by means of each electronic control unit.

2. Drive protection and management method of a pressurization system according to claim 1, further comprising calibrating said pressurization system, wherein at least one system maximum pressure is defined and set.

3. Drive protection and management method of a pressurization system according to claim 1, wherein defining an operating range which is common to all the hydraulic pumps of said pressurization system is further provided.

4. Drive protection and management method of a pressurization system according to claim 1, further comprising generating a temporary index which is typical of each of said hydraulic pumps.

5. Drive protection and management method of a pressurization system according to claim 1, comprising a detection of a plurality of pressure values by means of at least one pressure sensor at the delivery duct of each of said hydraulic pumps and calculating at least one first derivative of an interpolating function of said plurality of values by means of said electronic control unit at each of said hydraulic pumps.

6. Drive protection and management method of a pressurization system according to claim 1, comprising identifying and setting a waiting time in a sequential drive of said hydraulic pumps.

7. Drive protection and management method of a pressurization system according to claim 6, further comprising correcting said waiting time by means of a correction constant, which is set in said electronic control unit at each of said hydraulic pumps.

8. Drive protection and management method of a pressurization system according to claim 1, further comprising an iterative repetition of at least two operations of said method.

9. Drive protection and management method of a pressurization system according to claim 1, further comprising setting at least one threshold constant (shift) and/or at least one minimum operating range between a start pressure and a stop pressure).

10. Drive protection and management method of a pressurization system according to claim 9, in which switching on and off ranges are detected and determined by means of a time counter.

11. Pressurization system, comprising at least two hydraulic pumps (2), at least one pressure sensor at a delivery duct of each of said hydraulic pumps and an electronic control unit at each of said hydraulic pumps, said pressurization system being adapted to perform a method according to claim 1.

12. A method for managing and protecting a pressurization system including at least two operatively independent hydraulic pumps, comprising: setting a plurality of user parameters in an electronic control unit of each hydraulic pumps; detecting at least one pressure value by means of a pressure sensor located at a delivery duct of each of the hydraulic pumps; determining a drive impulse in a sequential and/or synchronized manner for said hydraulic pumps by managing and interpolating said user parameters and said pressure value of each hydraulic pump by means of the electronic control unit.

13. The method of claim 12 further comprising calibrating said pressurization system, wherein at least one system maximum pressure is defined and set.

14. The method of claim 12 wherein defining an operating range common to all the hydraulic pumps of said pressurization system is further provided.

15. The method of claim 12 further comprising generating a temporary index which is typical of each of said hydraulic pumps.

16. The method of claim 12 comprising a detection of a plurality of pressure values by means of at least one pressure sensor at the delivery duct of each of said hydraulic pumps and calculating at least one first derivative of an interpolating function of said plurality of values by means of said electronic control unit at each of said hydraulic pumps.

17. The method of claim 12 comprising identifying and setting a waiting time in a sequential drive of said hydraulic pumps.

18. The method of claim 17, further comprising correcting said waiting time by means of a correction constant, which is set in said electronic control unit at each of said hydraulic pumps.

19. The method of claim 12 further comprising an iterative repetition of at least two operations of said method.

20. The method of claim 12 further comprising setting at least one threshold constant (shift) and/or at least one minimum operating range between a start pressure and a stop pressure).

21. The method of claim 20 wherein switching on and off ranges are detected and determined by means of a time counter.

22. Pressurization system, comprising at least two hydraulic pumps, at least one pressure sensor at a delivery duct of each of said hydraulic pumps and an electronic control unit at each of said hydraulic pumps, said pressurization system being configured to perform the method according to claim 12.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In the drawings:

[0048] FIG. 1 represents a perspective view of an exemplary pressurization system according to a first embodiment of a method of the present disclosure;

[0049] FIG. 2 represents a top view of the pressurization system of FIG. 1;

[0050] FIG. 3 represents a front view of the pressurization system of FIG. 1;

[0051] FIG. 4 represents a side view of the pressurization system of FIG. 1;

[0052] FIG. 5 represents an exemplary diagram of operation of a method according to the present disclosure;

[0053] FIG. 6 represents a perspective view of an exemplary pressurization system not belonging to a claimed invention;

[0054] FIG. 7 represents a top view of the pressurization system of FIG. 6;

[0055] FIG. 8 represents a front view of the pressurization system of FIG. 6.

DETAILED DESCRIPTION

[0056] With reference to the figures, reference number 1 globally and schematically indicates a pressurization system, made according to the present disclosure.

[0057] FIGS. 1 to 4 represent in particular a pressurization system 1 comprising two hydraulic pumps 2. This embodiment is exemplary and non-limiting of the scope of protection defined by the attached claims, as it will also be more apparent herebelow. In fact, in general the pressurization system 1 can provide a number np of associated hydraulic pumps 2.

[0058] Each hydraulic pump 2 comprises an electric motor 3 and a hydraulic unit 4. Each hydraulic pump 2 comprises an electronic control unit 5.

[0059] The electric motor 3 and the hydraulic unit 4 are kinematically coupled by means of a driving shaft (not shown).

[0060] The electric motor 3 is preferably of the asynchronous two-phase type.

[0061] A liquid suction duct 6 and a liquid delivery duct 7 branch off from the hydraulic unit 4, which are coupled with a supply pipe 8 and a distributing pipe 9 of the pressurization system 1 respectively, preferably by threaded coupling.

[0062] The electric motor 3, in the exemplary embodiment of FIG. 1, is laterally coupled to the electronic control unit 5. The electronic control unit 5 comprises an electronic control board (not shown) and an interface display 10. The electronic control unit is powered by means of a connecting cable 11.

[0063] The electronic control unit 5 further comprises a pressure sensor (not shown), connected to the electronic control board. The pressure sensor is adapted to detect the pressure of the liquid inside the liquid delivery duct 7, and therefore to adjust the start/stop cycles of the pressurization system 1. Each hydraulic pump 2 comprises a pressure sensor. The present specification is exemplary and non-limiting of the scope of protection defined by the attached claims, as it will also be more apparent herebelow.

[0064] The electric motor 3 is cooled by means of a cooling fan 12 splined to the driving shaft at a rear closure 13. The cooling fan 12 is accommodated in a ventilated housing 14, coupled to the rear closure 13.

[0065] The electronic control unit 5 is adapted to manage and control at least one operating parameter of the hydraulic pump 2 of the pressurization system 1, in particular by means of the detections of the pressure sensor integrated in the structure of the hydraulic pump 2.

[0066] The variables managed and controlled by the electronic unit 5 comprise particularly, but not exclusively, the manometric pressure Hs measured by the pressure sensor of each hydraulic pump 2, the plant minimum pressure Hmin set by the user, the plant maximum pressure Hmax set by the user, a time unit t fixed equal for each hydraulic pump 2 in the installation.

[0067] Further, the electronic control unit 5 associates an individual temporary number Np with each hydraulic pump 2, which is variable from 1 to np, np being variable depending on the specific case, and an individual index n for each hydraulic pump 2.

[0068] Still further, in an embodiment with sequential switching on actions, a waiting time Tatt is determined, which is related to the time shift with which a sequential switching on or off of the hydraulic pumps 2 of the pressurization system 1 occurs.

[0069] A correction constant Kpc is also associated with the waiting time Tatt. This correction constant Kpc performs a predictive correction based on the evolution of the value of the first derivative and of the sign of the second derivative of the function interpolating the pressure measured by the sensor of each hydraulic pump 2. The values of the correction constant Kpc are storable in tables which can be modified in the installation of the pressurization system 1. If distributed withdrawals by the users occur the value of Kpc is comprised between zero and one. On the contrary, in case of detection of very small withdrawals with minimum pressure losses, for example under dripping conditions, the value of Kpc is much greater than 1.

[0070] As a result, the waiting time parameter Tatt for each pump with the individual temporary number Np is determined as TattNp=Kpc*Np*t.

[0071] According to a first embodiment calibrating the pressurization system 1 follows at the end of installing and setting parameters. In this operation the pressurization system 1 is pressurized at the maximum pressure Hmax. The maximum pressure Hmax is measured by any hydraulic pump 2 comprised between the np hydraulic pumps of the pressurization system 1. This hydraulic pump 2 is thus set as the reference hydraulic pump of the system and all the pressures measured by the sensors of each pump of the pressurization unit are defined as Hmax. This calibration allows possible calibration deviations of the pressure sensors of each hydraulic pump 2 to be avoided. A similar calibration can be further set regarding the minimum pressure Hmin. In this calibration the correction parameter Kpc is set equal to one.

[0072] Afterwards, defining an operating range is provided, defined by the maximum pressure Hmax and by the minimum pressure Hmin, which are common to all the hydraulic pumps 2 of the pressurization system 1.

[0073] An individual temporary number Np comprised between 1 and np is associated with the hydraulic pumps 2 which are different from the reference hydraulic pump.

[0074] Upon starting the pressurization system 1 each pressure sensor detects the manometric pressure Hs and the electronic control unit 5 determines the function interpolating the trend of the manometric pressure Hs and the first and second derivatives of this interpolating function.

[0075] If the value of the manometric pressure Hs is lower than the minimum pressure Hmin, the hydraulic pump 2 corresponding to the value one of Np is started and stays on until the manometric pressure Hs is higher than the maximum pressure Hmax.

[0076] Further, if the first and second derivatives indicate that the pressure in the circuit is increasing, a value which is higher than one is allocated to the correction constant Kpc, selected between the listed values as a function of the slope of the function of the detected manometric pressure Hs. In such conditions the hydraulic pump 2 corresponding to the value one of Np is bringing the pressure back to reference conditions providing the users with a delivery complying with the plant specifications.

[0077] If the first and second derivatives indicate that the pressure in the circuit is decreasing a value which is lower than one is allocated to the correction constant Kpc, selected between the listed values as a function of the slope of the function of the detected manometric pressure Hs.

[0078] In such conditions the hydraulic pump 2 corresponding to the value one of Np is not bringing the circuit pressure back to reference conditions and is not providing the users with a delivery complying with the specifications. Thereby TattNp is dynamically modified to meet the delivery request by the users with the highest possible comfort.

[0079] All the pumps steadily stay in the Hs monitoring without switching on for a time duration that is equal to TattNp. Only the pump with the individual temporary number Np which is equal to one has the waiting time value Tatt which is equal to zero.

[0080] Once the shorter observation time is elapsed, i.e. the one corresponding to the hydraulic pump 2 with the individual temporary number which is equal to two, if the manometric pressure value Hs measured by the pressure sensor is lower than the maximum pressure Hmax, this hydraulic pump also switches on. Similarly, the same is carried out for all the other hydraulic pumps 2 with the sequential order determined by the value TettNp.

[0081] When the manometric pressure Hs measured by the pressure sensor in each pump is higher or equal to the maximum pressure Hmax all the hydraulic pumps switch off since the whole circuit is pressurized according to the required specifications.

[0082] Once all the hydraulic pumps 2 are switched off the individual indices of the hydraulic pumps 2 are updated according to the following law: [0083] If Np=np then Np=1 is set [0084] If Np=n then Np=n+1 is set

[0085] The described first embodiment is particularly effective in equally distributing wear in the mechatronic components of the hydraulic pumps 2.

[0086] In FIG. 5 the diagram of operation and performances of the pressurization system 1 provided with np pumps of the just described type is represented in a graph Q/H, where Q is the flow rate required to the pressurization implant and H the relevant hydraulic head. Curves of operation with steady, proportional and quadratic H are further represented.

[0087] In a second embodiment of the disclosure in the initial operation the individual temporary number Np comprised between the values one and np is generated and associated in a random manner with each pump, and for each of them the electronic control unit 5 calculates the waiting time parameter TattNp as described.

[0088] Switching on and off the pumps which is similar to the one provided in the first embodiment then follows.

[0089] Once the switching off of all the pumps is completed, an iterative repetition is thus provided.

[0090] In the described second embodiment an overlap of the individual temporary number Np for several hydraulic pumps can occur and these hydraulic pumps can thus switch on at the same time. In that case the operating time is proportionally reduced, improving the distribution of the stochastic process.

[0091] Alternately it is possible to provide a switching on and off of the hydraulic pumps 2 determined by the electronic control unit 5 based on ranges between the maximum pressure Hmax and the minimum pressure Hmin, suitably shifted for each hydraulic pump 2 of the pressurization system 1.

[0092] In this case, in the electronic control unit 5 the variable defined as shift, i.e. a threshold constant, is set, being required to define the switching on and off ranges of each hydraulic pump 2. The definition of the switching on and off ranges is detected and determined by means of a time counter. Further a minimum operating range x between the switching on pressure and the switching off one of each hydraulic pump 2 is set, in order to carry out an optimal distribution of the switching on time of each hydraulic pump 2 and reduce the number of starts per hour. The minimum range x is generally, but not limitedly, fixed between 1 and 1.5 bar.

[0093] Each hydraulic pump 2 is identified by means of an identification index ID.

[0094] By defining a suitable threshold constant shift the distribution of all the operating ranges of the hydraulic pumps 2 is set.

[0095] Indicating with t a measuring tolerance of the pressure sensor, a threshold constant shift that is greater than t and equal for all the hydraulic pumps 2 is fixed. For each hydraulic pump 2 the switching on pressure Pstart, stop pressure Pstop values and the number of pumps np are set.

[0096] Preferably, but not exclusively, the following law is adopted:

Pstop,i=Pstopi.Math.shift

Pstart,i=Pstart+(npi)shift

[0097] Starting from boundary conditions to be fulfilled:

shift=(PstopPstartx)/(np1)

shiftmin=t

[0098] An operation law is obtained:

(Pstop,minPstart,max)=Pmin=t.Math.(np1)+x

[0099] Each pump, based on the identification index ID thereof set by the user, is set according to its own i-th thresholds, so as to equally split the operating pressure ranges. In order to subject the pumps to a similar degree of wear, an alternation of operation of the hydraulic pumps 2 is obtained by suitably swapping the reference index ID of each of them. In fact, keeping each pump completely autonomous from the other ones, a supply network voltage period of the pressurization unit 1 as a clock function is preferably used as a synchronising signal for swapping the identification index ID. The supply network voltage period is measured by calculating the sinusoidal voltage peaks. The preferred but not exclusive selection of this signal makes the synchronism very strong since, even in case of fluctuation of the network frequency, the hydraulic pumps would stay synchronized, being all exposed to the same fluctuation.

[0100] Hence, the operating time of the single hydraulic pump 2 is calculated and the index ID swapping is suitably selected accordingly.

[0101] Alternately, it is possible to use microcontrollers with integrated RTC (Real Time Clock).

[0102] In FIGS. 6 to 8 a pressurization system 1, not belonging to a claimed invention, is represented, comprising three hydraulic pumps 2, of which a reference hydraulic pump 2 and two interlocked hydraulic pumps 15 powered by the electronic control unit 5 of this hydraulic pump 2 operating with one of the above-described methods. The interlocked hydraulic pumps 15 are connected to the single reference hydraulic pump 2 by means of connecting pipes 16.

[0103] Advantageously, the present disclosure allows the number of drives of the pressurization system to be minimized thereby protecting the electromechanical devices being involved.

[0104] Further, the method according to the disclosure allows only one measured physical parameter to be adopted, such as pressure, minimizing problems deriving from possible measurement errors.

[0105] Still further, the present disclosure allows a highly efficient pressurization system with mutually independent hydraulic pumps to be created in a cost-effective way.

[0106] A person skilled in the art will also appreciate how the present disclosure can be implemented in pre-existing assemblies without particular expedients.

[0107] The person skilled in the art will understand that the presented embodiment can be subject to various modifications and changes, according to specific and contingent requirements, all falling within the scope of protection of the disclosure, as defined by the following claims.