Patent Publication Number: US-2018038364-A1

Title: Method for operating an undulating diaphragm pump and an undulating diaphragm pump operating system

Description:
TECHNICAL DOMAIN 
     The present invention relates to the technical field of undulating diaphragm pumps and concerns, more particularly, a method for operating an undulating diaphragm pump, as well as an operating system for an undulating diaphragm pump. 
     The invention is applicable to all domains where undulating diaphragm pumps are used, but has an advantageous application in the field of aeronautics where undulating diaphragm pumps may be used, for example, for the evacuation of wastewater contained in a water-holding tank of a gray water management system for aircraft washrooms, or even to circulate fuel within the aircraft. 
     PRIOR ART 
     It is known from the prior art an undulating diaphragm pump comprising, generally, of a pump body delimiting a chamber into which an inlet pipe and an outlet pipe lead. The undulating diaphragm pump comprises an undulating diaphragm capable of having a central opening, extending into the undulating diaphragm pump chamber, in particular between a lower end-plate and an upper end-plate of the undulating diaphragm pump. The undulating diaphragm pump contains actuating means enabling the actuation of the undulating diaphragm, electrically powered by a voltage at a given frequency. 
     The actuating means notably enable the undulating diaphragm to oscillate and undulate. Thus, the undulating diaphragm is able to move between the lower end-plate and upper end-plate respectively of the undulating diaphragm pump at a frequency equivalent to the electrical supply frequency of the actuating means. 
     If the actuating means are powered by a continuous current, an inverter is arranged in order to generate a periodic alternating supply at the given frequency. 
     Thus, actuated by the actuating means, the undulating diaphragm oscillates and undulates such as to propagate a wave front which causes, on the one hand, the pumping of a fluid to be pumped from the inlet pipe to the undulating diaphragm pump chamber and, on the other hand, a discharge of the fluid to be pumped from the undulating diaphragm pump chamber to the outlet pipe. 
     This type of undulating diaphragm pump gives complete satisfaction in that it requires reduced maintenance, and in that it is not sensitive to cavitation phenomena, nor to the quantity and size of waste or foreign bodies potentially present within the fluid to be pumped. 
     However, the use of known undulating diaphragm pumps is not optimal. It can be further improved, notably in terms of energy consumption and performance. 
     DESCRIPTION OF THE INVENTION 
     One of the aims of the invention is therefore to provide a method for operating an undulating diaphragm pump as well as an operating system for an undulating diaphragm pump, which enables the use of an undulating diaphragm pump to be optimized, notably by reducing the energy consumption thereof, and by increasing the performance thereof. Furthermore, alternatively or in combination, the present invention also proposes to improve all of the operating parameters of the undulating diaphragm pump, particularly as a function of the application concerned. 
     To this end, an undulating diaphragm pump operating method has been developed comprising at least one undulating diaphragm and actuating means of the undulating diaphragm, the actuating means being electrically powered according to a given frequency or voltage to make the undulating diaphragm oscillate and undulate. 
     According to the invention, the method consists in modifying the electrical supply frequency and/or voltage of the actuating means according to at least one operating parameter, determined in advance, of the undulating diaphragm pump. 
     In this way, depending upon the use of the undulating diaphragm pump, it is possible to modify the electrical supply frequency and/or voltage of the actuating means of the undulating diaphragm in order to vary at least one operating parameter of the undulating diaphragm pump such that it operates in an optimal way, according to the application concerned. For example, the operation of the undulating diaphragm pump is optimized when the undulating diaphragm pump consumes as little energy as possible while offering maximum performance. Modifying the electrical supply frequency and/or voltage of the actuating means of the undulating diaphragm may also enable the undulating diaphragm pump to operate at a desired operating level. 
     Indeed, to be effective and to have good performance, the oscillation frequency of the undulating diaphragm should, for example, be equivalent to a resonant frequency defined by the internal characteristics of the undulating diaphragm pump and of the fluid to be pumped. 
     When the undulating diaphragm pump is implemented within an aircraft, the oscillation frequency of the undulating diaphragm is dictated by the electricity supply frequency of the aircraft&#39;s electrical network. However, in practice and due to the nature of each part constituting an undulating diaphragm pump, it is difficult to manufacture an undulating diaphragm pump of which the resonant frequency is exactly equal to a given electrical supply frequency. 
     In practice, a resonant frequency is generally observed which is different to the desired frequency. In this situation, the operating method according to the invention, enables, for example, the electrical supply frequency and/or voltage of the actuating means of the undulating diaphragm to be modified, in order to vary the oscillation frequency of the undulating diaphragm so that it reaches the resonant frequency specific to the undulating diaphragm pump, which, as cited above, also depends upon the fluid to be pumped. 
     Depending upon the use of the undulating diaphragm pump, it may be necessary to verify whether the predetermined parameter reflects the desired use of the undulating diaphragm pump. According to an example of a particular embodiment of the operating method according to the invention, this comprises steps consisting of: 
     determining an operating parameter of the undulating diaphragm pump; 
     verifying whether the determined operating parameter has reached a predetermined target value;
         if the determined operating parameter does not reach the predetermined target value, varying the electrical supply frequency and/or voltage of the actuating means until the determined operating parameter reaches the predetermined target value.       

     According to a particular embodiment, the step consisting of verifying whether the determined operating parameter has reached the predetermined target value may consist in verifying whether it is situated within a predetermined value range. 
     Since the behavioral law of the determined parameter is not linear, the step consisting of verifying whether the determined operating parameter has reached the predetermined target value may also consist in verifying whether the determined operating parameter has reached a maximum or minimum value, such that the electrical supply frequency and/or voltage is successively increased and decreased in order to determine whether the determined operating parameter has reached the maximum or minimum value. 
     According to another embodiment, the variation of the electrical supply frequency and/or voltage, may obey a control logic depending upon the determined operating parameter. 
     The invention also concerns an operating system for an undulating diaphragm pump. The undulating diaphragm pump operating system comprises a pump, comprising notably an undulating diaphragm and actuating means of the undulating diaphragm electrically powered according to a given frequency and/or voltage to make the undulating diaphragm oscillate and undulate. 
     According to the invention, the undulating diaphragm pump operating system comprises a control unit able to control the actuating means according to at least one operating parameter, determined in advance, of the undulating diaphragm pump. 
     According to a particular embodiment, the control unit comprises an electrical supply frequency and/or voltage regulating component, arranged between the electrical supply and the actuating means. 
     Certain operating parameters, such as for example the electrical supply voltage or frequency, power, etc., may be determined, and notably calculated, directly by the control unit. However, depending upon the operating parameter(s) to be determined, the undulating diaphragm pump operating system may comprise measurement means capable of sending at least one measurement of at least one undulating diaphragm pump operating parameter to the regulating component. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Of course, the various characteristics, variants and/or embodiments of the present invention may be associated with each other according to various combinations insofar as they are not incompatible or exclusive of one another. 
       Likewise, the present invention will be better understood and other characteristics and advantages will emerge upon reading the detailed description which follows comprising embodiments given by way of illustration with reference to the appended drawings, presented by way of non-limiting examples, which may be used to complete the understanding of the present invention and the description of the embodiment thereof and, where appropriate, contribute to the definition thereof, wherein: 
         FIG. 1  represents a schematic diagram of the operating system of the diaphragm pump according to the invention; 
         FIG. 2  represents, schematically, viewed from the side, the interior of an undulating diaphragm pump according to one embodiment; 
         FIG. 3  represents a schematic diagram of an operating method of an undulating diaphragm pump according to the invention; 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     It should be noted that, within the figures, structural and/or functional elements that are common to the various embodiments may have the same references. Thus, unless stated otherwise, such elements have identical structural, dimensional and material elements. 
     With reference to  FIG. 1 , the invention relates to an operating system ( 1 ) for an undulating diaphragm pump ( 2 ) of which the use is optimized, for example, to operate according to the actual need of the pumping characteristics. Thus, it is possible to reduce the energy consumption of the undulating diaphragm pump ( 2 ) and/or to increase the performance of the undulating diaphragm pump ( 2 ), and/or to improve any operating parameter of the undulating diaphragm pump ( 2 ) according to the application concerned. 
     In reference to  FIG. 2 , which illustrates an example of an embodiment of the undulating diaphragm pump ( 2 ), this comprises a pump body ( 3 ) delimiting a chamber ( 4 ) into which an inlet pipe ( 5 ) and outlet pipe ( 6 ) lead. The undulating diaphragm pump ( 2 ) comprises an undulating diaphragm ( 7 ) extending into the chamber ( 4 ), in particular an undulating diaphragm ( 7 ) in the form of a disc having a central, circular opening ( 8 ). The undulating diaphragm ( 7 ) is obtained from a deformable material such as a silicone elastomer for example or similar. Advantageously, the undulating diaphragm ( 7 ) is arranged between a lower end-plate and an upper end-plate. 
     The undulating diaphragm pump ( 2 ) comprises actuating means ( 9 ) enabling the undulating diaphragm ( 7 ) to be oscillated and undulated thereby enabling the pumping operations as such. 
     The actuating means ( 9 ) are powered by an electrical supply ( 10 ) delivering a given electrical supply voltage and/or frequency. The actuating means ( 9 ) enable electrical energy provided by the electrical supply ( 10 ) to be transformed into an alternating movement, advantageously into a linear alternating movement. The alternating movement causes the oscillating and undulating movement of the undulating diaphragm ( 7 ). 
     More particularly and in reference to  FIG. 1 , the undulating diaphragm ( 7 ) is secured to a mobile structure ( 11 ) connected to the actuating means ( 9 ) in the form of an electromagnet ( 12 ) comprising a mobile magnet ( 13 ). Thus, when the electromagnet ( 12 ) is electrically-powered by the electrical supply ( 10 ), the mobile magnet ( 13 ) oscillates and causes oscillation of the mobile structure ( 11 ) and therefore the oscillation and undulation of the undulating diaphragm ( 7 ). The oscillation and undulation of the undulating diaphragm ( 7 ) enables a wave front to be generated causing the circulation of a fluid to be pumped through the diaphragm pump ( 2 ). The mobile structure ( 11 ), also in the form of a disc, also serves to protect the undulating diaphragm ( 7 ). 
     According to the invention, and in reference to  FIG. 2 , the operating system ( 1 ) of the undulating diaphragm pump ( 2 ) comprises a control unit ( 14 ), such as an electronic computer, to capture signals and define running conditions. The control unit ( 14 ) is arranged between the actuating means ( 9 ) and the electrical supply ( 10 ). In other terms, the control unit ( 14 ) is electrically-supplied and controls the electrical supply to the actuating means ( 9 ) of the undulating diaphragm pump ( 2 ). 
     The control unit ( 14 ) manages the electrical/electronic interfaces of the undulating diaphragm pump ( 2 ). Furthermore, the control unit ( 14 ) enables an output signal ( 18 ) to be created, notably an electrical power signal capable of being sent to the actuating means ( 9 ) of the undulating diaphragm ( 7 ) of the undulating diaphragm pump. 
     More precisely, the control unit ( 14 ) comprises a regulating component ( 15 ). The regulating component ( 15 ) is able to modify and/or regulate the electrical supply frequency and/or voltage of the actuating means ( 9 ). Advantageously, software and/or an optionally programmable logic circuit compose the electrical supply frequency and/or voltage regulating component ( 15 ) of the actuating means ( 9 ). The regulating component ( 15 ) receives, at the input, an input signal ( 19 ), notably an electrical supply input voltage and/or input frequency, such as for example 400 Hz, coming from, for example, the aircraft&#39;s electrical network. As an output, the regulating component ( 15 ) delivers the output signal ( 18 ), notably an output frequency and/or output voltage, preferably a regulated output frequency and/or output voltage, which supplies the actuating means ( 9 ) of the undulating diaphragm ( 7 ). The regulating component ( 15 ) regulates the electrical supply frequency and/or voltage of the actuating means ( 9 ) according to at least one predetermined operating parameter, notably measured or calculated in advance, of the undulating diaphragm pump ( 2 ). 
     For example, the regulating component ( 15 ) may vary the electrical supply frequency and/or voltage of the actuating means ( 9 ) according to one or more determined target values to be reached for one or more determined operating parameters. Alternatively, or additionally, the regulating component ( 15 ) may vary the electrical supply frequency and/or voltage according to a range of tolerance values wherein the measured or calculated parameters should be found. The regulating component ( 15 ) may also regulate the electrical supply frequency and/or voltage such as to respect a control logic. 
     In the example of the illustrated embodiment, the input voltage delivered by the electrical supply ( 10 ) is continuous. Thus, the control unit ( 14 ) may also include a continuous/alternating inverter ( 16 ) to generate a periodic alternating output voltage to supply the actuating means ( 9 ) of the undulating diaphragm ( 7 ). 
     According to a particular embodiment, measurement means ( 17 ) are also connected, either to the regulating component ( 15 ) or, where applicable, to the continuous/alternating inverter ( 16 ), or directly to the undulating diaphragm pump ( 2 ). The measurement means ( 17 ) are able to measure, as well as the operating parameters of the undulating diaphragm pump ( 2 ), the output signal ( 18 ) of the regulating component ( 15 ) and/or of the continuous/alternating inverter ( 16 ). The control unit processing unit ( 14 ) is then able to compare the output signal ( 18 ) with the input signal ( 19 ), notably within the regulating component ( 15 ). The measurement means ( 17 ) may be of different types depending upon the parameter to be measured. They may, for example, comprise sensors, such as pressure, flow rate, temperature sensors. 
     In reference to  FIG. 3 , during the operation of the operating system ( 1 ) of the undulating diaphragm pump ( 2 ) according to the invention, and in a determination step (A), the control unit ( 14 ) calculates, or even the measurement means ( 17 ) measure at least one operating parameter of the undulating diaphragm pump ( 2 ). If several operating parameters are measured or calculated, these may be taken in isolation or in combination. 
     By way of example, the measured or calculated operating parameter may constitute: 
     a voltage and/or current applied to the actuating means ( 9 ); 
     a phase shift between the electrical supply current and voltage applied to the actuating means ( 9 ); 
     the output power of the undulating diaphragm pump ( 2 ); 
     the power consumed by the undulating diaphragm pump ( 2 ); 
     the output pressure of the undulating diaphragm pump ( 2 ); 
     or any other operating parameter, such as a temperature, pressure, flow rate, performance, etc. 
     In an information transmission step, the control unit ( 14 ) or the measurement means ( 17 ) send the value of the measured or calculated operating parameter to the regulating component ( 15 ). 
     In a verification step (B), the regulating component ( 15 ) conducts a verification consisting in determining whether the measured operating parameter(s) has/have reached the predetermined target value(s). 
     The predetermined target value(s) may be of different types. By way of example, they may be for verifying whether one of the measured or calculated operating parameters has reached a particular value, or whether it has reached a multitude of target values notably defining a range of tolerance values for the measured or calculated operating parameter. 
     In this way, in the negative, if the regulating component ( 15 ) determines that the measured or calculated operating parameter(s) has/have not reached the predetermined target value(s), in an adaptation step (C), the regulating component ( 15 ) varies the input signal ( 19 ), in particular the electrical supply frequency and/or voltage of the actuating means ( 9 ). A new measurement or a new calculation of the operating parameter is then conducted according to the previously described measurement or calculation step (A), and a new verification according to the previously described verification step (B) is performed. 
     The oscillation frequency of the undulating diaphragm ( 7 ) influences the flow rate of the undulating diaphragm pump ( 2 ), while the power supply voltage influences the oscillation amplitude of the undulating diaphragm ( 7 ), and therefore enables the power of the undulating diaphragm pump ( 2 ) to be varied. The flow rate and the operating power of the undulating diaphragm pump ( 2 ) are not constant. The invention thus enables the running of the undulating diaphragm pump ( 2 ) to be optimized in order that it always functions in an optimal way. 
     It follows from the above that the invention provides a method of operating an undulating diaphragm pump ( 2 ), as well as an operating system ( 1 ) for an undulating diaphragm pump ( 2 ), which enable the use of the undulating diaphragm pump ( 2 ) to be optimized, by regulating the electrical supply to the undulating diaphragm pump ( 2 ) according to the actual need and application concerned. 
     The invention thus enables the energy consumption of the undulating diaphragm pump ( 2 ) to be regulated, the performance, as well as any calculable or measurable parameter, to be optimized. 
     Obviously, the invention is not limited to the embodiments previously described and provided by way of example only. It includes various modifications, alternative forms and other variants which may be envisaged by a person skilled in the art within the scope of the present invention and notably all combinations of the various operating modes described above, which may be taken separately or in combination.