Centrifugal pump and pump system

Abstract

The inventions provide a centrifugal pump (1) for pumping a fluid. The pump (1) comprises a pump body (10) having an impeller housing (12), an inlet (11) and an outlet (13), which together define a flow path for the fluid, an impeller (20), which is rotatably supported within the impeller housing (12), for transporting the fluid from the inlet (11) along the flow path to the outlet (13), and a fluid measuring device for measuring a pressure of the fluid. The fluid measuring device comprises one or a plurality of measuring units (31, 32, 33), each being arranged to measure the pressure of the fluid at a respective upstream or downstream position of the flow path relative to the impeller (20). Each of the one or the plurality of measuring units (31, 32, 33) comprises a sensor unit (311, 321) and a related measuring section (312, 322, 332) enclosing a respective measuring space (313, 323, 333), wherein each measuring space (313, 323, 333), is spatially separated from the flow path and arranged to hydraulically communicate through a communication section (314, 324, 334) of the respective measuring section (312, 322, 332) with an upstream position or a downstream position of the flow path relative to the impeller (20), such that the measuring space (313, 323, 333) is filled with fluid from the flow path when the fluid is transported by the impeller (20) along the flow path. Each sensor unit (311, 321) is thereby arranged to measure the pressure of the fluid inside the measuring space (313, 323, 333) of the related measuring section.

Description

[0001] CENTRIFUGAL PUMP AND PUMP SYSTEM

[0002] Technical Field

[0003] The invention relates to a centrifugal pump for pumping a fluid and to a pump system comprising multiple centrifugal pumps.

[0004] Background of the invention

[0005] Centrifugal pumps are well-known devices from the field of fluid mechanics, which are used to generate a fluid flow by means of an energy conversion of rotational kinetic energy of an impeller into hydrodynamic energy of the fluid.

[0006] In general, the fluid enters the pump via an inlet of a pump body, is accelerated by the rotating impeller so as to flow radially outward, for example into a volute, and exits the pump via an outlet of the pump body.

[0007] In order to quantify the effect of the pump as component within a fluid mechanical system, one or more properties of state of the fluid are measured within the flow path, preferably at an upstream and at a downstream position of the impeller, so as to obtain differential values such as a differential fluid pressure or the like.

[0008] It is thereby desirable to measure the desired quantities inside the pump, i.e., close to the pump’s impeller, in order to correctly assess the pump’s operation state, for example for controlling and assessing the health of the pump.

[0009] However, moving the measurement point closer to the impeller leads to erroneous measurement results, as falsifying influences such as turbulences of the fluid flow or vibrations of certain components of the pump in the vicinity of the impeller increase while moving closer to impeller.

[0010] Thus, an object of the present invention is to provide an improved possibility for accurate measurements of a fluid’s pressure within a centrifugal pump or pump system.

[0011] Summary of the invention

[0012] The object of the present invention is achieved by the solution provided in the enclosed independent claim. Advantageous implementations of the present invention are further defined in the dependent claims.

[0013] According to a first aspect of the invention, a centrifugal pump for pumping a fluid is provided. The pump comprises a pump body having an impeller housing, an inlet and an outlet, which together define a flow path for the fluid, an impeller, which is rotatably supported within the impeller housing, for transporting the fluid from the inlet along the flow path to the outlet, and a fluid measuring device for measuring a pressure of the fluid. The fluid measuring device comprises one or a plurality of measuring units, each being arranged to measure the pressure of the fluid at a respective upstream or downstream position of the flow path relative to the impeller. Each of the one of the plurality of measuring units comprises a sensor unit and a related measuring section enclosing a respective measuring space, wherein each measuring space is spatially separated from the flow path and arranged to hydraulically communicate through a communication section of the respective measuring section with an upstream position or a downstream position of the flow path relative to the impeller, such that the measuring space is filled with fluid from the flow path when the fluid is transported by the impeller along the flow path. Each sensor unit is thereby arranged to measure the pressure of the fluid inside the measuring space of the related measuring section.

[0014] By means of the provided setup, the pressure is not measured directly within the flow path itself, but within the spatially separated, flow-calmed measuring space, such that the amount of measurement falsifying influences present within the suggested measuring space is less compared to the flow path.

[0015] Examples for such falsifying influences might be turbulences of the fluid flow within the flow path, or compression waves, caused by vibrating parts of the pump, especially from the impeller, which are travelling along the flow path.

[0016] Due to the spatially separated setup of the measuring space, these influences are not or only partially transmitted to the measuring space, such that the sensor unit is no longer directly exposed to these influences like in case of the typically known arrangement within the fluid path.

[0017] Consequently, a stabilized measuring environment is provided which reduces the measurement errors of the sensor unit, as the pressure is evened out inside the measuring space.

[0018] In that manner, the actual measuring points can be moved closer to the impeller without leading to a falsification of the measurement results, such that an accurate measurement of the fluid’s pressure can be realized close to the pump’s ‘heart’, namely the impeller.

[0019] A measuring point can thereby be understood as a spatial point of the flow path, at which the fluid leaves the flow path via the communication section. The suggested arrangement therefore allows a more reliable and representative assessment of the centrifugal pump’s operating state, which might be used later on in a respective control procedure, e.g., for controlling the pump’s differential pressure by means of a rotational speed of the impeller, or for performance optimization, energy efficiency monitoring, and condition monitoring in real-time.

[0020] The flow path might be described via a streamline, a collection of multiple streamlines, or as flow through volume, along which the fluid is transported so as to pass from the inlet to the outlet.

[0021] The arrangement ‘spatially separated from the flow path’ is to be understood that way, that the measuring space is not an immediate part of the flow path, i.e., it does not correspond to a volume which have to be passed by the fluid so as to reach from the inlet to the outlet.

[0022] In other words, a fluid flow direction inside the measuring space does not correspond to a main flow direction of the flow path at the respective measuring point. However, this shall not exclude an arrangement in which the measuring space is located within a flow channel of the pump together with the flow path, as long as the respective measuring section spatially separates the flow path from the measuring space.

[0023] Preferably, the measuring sections are arranged such that the measuring spaces are located adjacent to the flow path. By means of such an arrangement, the fluid mechanical losses resulting from the fluid’s flow from the flow path into the measuring space via the communication section can be kept low.

[0024] The arrangement ‘adjacent to the flow path’ is to be understood that a length of the communication section in a flow direction through the communication section is preferably smaller than a width of a cross section of the flow path, running orthogonal to a main flow direction of the flow path, at the respective measuring point.

[0025] Preferably, the aforesaid length of the communication section shall be less than 90%, more preferably less than 50%, more preferably less than 25%, more preferably less than 10% and most preferably less than 5% of the aforesaid width of the cross section.

[0026] A fluid can be understood as liquid or gas or a mixture thereof. Preferably, the fluid to be pumped by the provided centrifugal pump is a liquid or a mixture of gas and liquid with the liquid being the main component of the mixture.

[0027] The pressure to be measured can be understood as any pressure quantity of the fluid, which might be an absolute pressure or a relative pressure with respect to a reference pressure. Said reference pressure can be for example a predefined value or a pressure measurement value at another measuring point of the pump.

[0028] Sensor units of the one or the plurality of measuring units might be formed as separate components, but can also be incorporated in a common sensor unit, such as a differential pressure sensor.

[0029] The pump body might be formed integrally or might be an assembly of several components. Preferably, the inlet and the outlet might be integrally formed together with a first part of the impeller housing. Alternatively, the inlet and / or the outlet might be provided as separate components, mounted to the impeller housing, preferably in a detachable manner.

[0030] The sensor unit of one or more of the one or the plurality of measuring units is preferably connected to the respective measuring space by means of a connection port within the related measuring section.

[0031] Preferably, the fluid measuring device comprises 2, 3, 4, 5 or 6 measuring units, wherein it is preferable that at least one measuring unit is arranged to measure the pressure at an upstream position and at least one measuring unit is arranged to measure the pressure at a downstream position relative to the impeller.

[0032] The usage of multiple measuring units enables pressure averaging to compensate for an uneven fluid velocity within the pump.

[0033] In a preferred embodiment, the fluid measuring device comprises at least two measuring units, wherein a first measuring unit of the at least two measuring units is arranged to measure the pressure of the fluid at an upstream position of the flow path relative to the impeller, and a second measuring unit of the at least two measuring units is arranged to measure the pressure of the fluid at a downstream position of the flow path relative to the impeller.

[0034] By means of this arrangement, the advantageous measurement principle is extended to both, an upstream and a downstream side of the impeller, so as to be able to assess a change of the pressure of the fluid caused by the transportation via the impeller.

[0035] In a preferred embodiment, the fluid measuring device is configured to determine a differential pressure value of the of the fluid based at least on the measurement values from both, the sensor unit of the first measuring unit and the sensor unit of the second measuring unit. Preferably, the fluid measuring devices comprises an evaluation unit, which is connected to all of the sensor units of the measuring units and which is configured to evaluate their respective measurement results.

[0036] In a preferred embodiment, the sensor unit of the first measuring unit and the sensor unit of the second measuring unit are designed as separate components.

[0037] In that manner, the measurement values can be independently accessed by the fluid measuring device and can be used, for example, for controlling the centrifugal pump or for condition monitoring.

[0038] In a preferred embodiment, the sensor unit of the first measuring unit and the sensor unit of the second measuring unit are designed together in the form of a differential pressure sensor, wherein the differential pressure sensor is preferably configured to measure the differential pressure.

[0039] In other words, the sensor units of the first and the second measuring unit are set up so as to be one common sensor unit, namely, the differential pressure sensor.

[0040] In this case, the fluid measuring device comprises the at least two measuring units, arranged at an upstream and at a downstream position relative to the impeller. Each of the at least two measuring units comprises a measuring section enclosing a respective measuring space, wherein each measuring space is spatially separated from the flow path and arranged to hydraulically communicate through a communication section of the respective measuring section with the respective upstream position or downstream position of the flow path relative to the impeller, such that the measuring space is filled with fluid from the flow path when the fluid is transported by the impeller along the flow path. Further, the fluid measuring device comprises a differential pressure sensor which is connected to the measuring spaces of the at least two measuring units and which is arranged to measure the differential pressure of the fluid between the measuring space of the first measuring unit and the measuring space of the second measuring unit.

[0041] This enables a simpler construction with less complexity of the fluid measuring device, wherein the use of a single integrated differential measuring sensor allows to measure the differential value in the pump.

[0042] Differential measuring sensors, and especially differential pressure sensors, can be designed very compact and can specifically be tailored to the application of measuring differential values, leading to more accurate results than using two independent sensors, for which their respective measurement deviations would simply add up. In a preferred embodiment, a first hydraulic connection channel of the first measuring unit, connecting its sensor unit with the measuring space of its measuring section, and a second hydraulic connection channel of the second measuring unit, connecting its sensor unit with the measuring space of its measuring section, are formed by a single measuring channel connecting the measuring space of the first measuring unit and the measuring space of the second measuring unit, wherein the measuring channel preferably extends straight through the pump body.

[0043] Preferably, said measuring channel is thereby completely formed as vacancy with the pump body. This allows to keep the number of components of the pump low, e.g., instead of using additional tubes, and also allows to keep the distance between differential measuring sensor and the two measuring spaces low.

[0044] In a preferred embodiment, for one or more of the one or the plurality of measuring units, a hydraulic connection channel connecting the respective sensor unit with the measuring space of its related measuring section is at least partially formed as a vacancy within the pump body, in particular it is completely formed as vacancy.

[0045] A remainer of a connection channel, which is solely partially formed as vacancy, might be formed by means of an additional component, such as connecting tube or hose.

[0046] Alternatively, the hydraulic connection channel can also be formed by means of an additional component, such as connecting tube or hose.

[0047] In a preferred embodiment, for one or more of the one or the plurality of measuring units, the communication section of the respective measuring section comprises at least one or a plurality of communications channels, wherein each communication channel is preferably formed as a through-hole, more preferably in the form of a skewed or straight generalized cylindrical hole with a circular or longitudinal cross-section, wherein the plurality of channels are preferably evenly distributed along the respective measuring section.

[0048] This allows a simple and reliable realization of the hydraulic communication with the flow path, so as to ensure, that the measuring space is filled with fluid from the flow path and that the properties of state of the fluid within the measuring space are not or only slightly falsified due to the flow through the communication section.

[0049] A generalized cylinder is to be understood as a geometric object of extruding a two- dimensional flat shape along an extrusion axis. In case the extruding axis is orthogonal to a plane of the flat shape, a straight cylinder is obtained, otherwise a skewed cylinder is obtained. In case the two-dimensional flat shape is a circle, the normally-known cylinder (or circular cylinder) is obtained.

[0050] The shape of the communication channel shall not be limited to a through hole, but can also be realized as a slot or as an elongated slot.

[0051] Preferably, the communication section has 2 to 12 communication channels, more preferably it hast 4 to 10, and more preferably it has 8 communication channels.

[0052] Preferably, the first and / or the second measuring unit comprise measuring sections realized according to one or more of the afore-described configurations.

[0053] In a preferred embodiment, for at least one of the one or more of the one or the plurality of measuring units, whose communication sections comprises at least one or a plurality of communications channels, the one or plurality of communication channels extend in a direction radial to a transporting direction of the fluid when being transported through the flow path.

[0054] Preferably, the first and / or the second measuring unit comprise measuring sections realized in the afore-described configuration.

[0055] Preferably, a connection port at the respective measuring space for connecting the respective measuring space with the related sensor unit of the at least one of the one or more of the one or the plurality of measuring units is arranged non-coaxially to the at least one or to any one of the plurality of communication channels.

[0056] This allows to reduce falsifying effects during the measurement, as the fluid entering the measuring space does not flow directly onto the connection port.

[0057] Preferably, the measuring space enclosed by the respective measuring section of one or more of the one or the plurality of measuring units is circumferentially arranged around the flow path.

[0058] Circumferentially arranged is to be understood, that the measuring space circumferentially surrounds the flow path, preferably with respect to a cross-section running orthogonal to the main flow direction of the flow path, in a partial or more preferably in a full manner.

[0059] In a preferred embodiment, the measuring space enclosed by the respective measuring section of one or more of the one or the plurality of measuring units has an annular or ring shape (i.e. is ring-shaped) or has the geometric shape of a hollowed generalized cylinder, which is circumferentially arranged around the flow path. The hollow part thereby houses the flow path, such that measuring space surrounds the flow path in a cross section of the flow path, running orthogonal to a flow direction of the flow path, at the respective measuring point in a full manner.

[0060] This facilitates the arrangement of a respective measuring space adjacent to the flow path.

[0061] Preferably, the measuring space has an annular or ring shape (i.e. is ring-shaped) or has the geometric shape of a hollowed circular cylinder, as these shapes are easy to produce.

[0062] Preferably, the measuring space is adapted to a contour of the pump body surrounding the flow path at the respective measuring point. Typically, such a contour is circular, but can also be an ellipse or a polygonal.

[0063] Preferably, the first and / or the second measuring unit comprise measuring sections realized according to one or more of the afore-described configurations.

[0064] In a preferred embodiment, for one or more of the one or the plurality of measuring units, the communication section of the respective measuring section is formed as a gap section within the pump body, with the gap section being circumferentially arranged around the flow path, so as to partially or completely surround the flow path with respect to a circumferential direction.

[0065] In that manner, the fluid can easily flow via the gap section into the measuring space. The gap can be easily provided, e.g. by layout and / or assembly (i.e. relative position) of different parts of the pump body.

[0066] In a preferred embodiment, for one or more of the measuring sections their respective gap section comprises a first subsection and one or more second subsections, connected in series to the first subsection.

[0067] Hence, the measuring section can be designed according to the given needs and design of the overall pump body.

[0068] The respective subsections are preferably connected by an angled or bent section.

[0069] Hence, as the measuring section extends away from the flow path in a kind of meander-type path, such that any variations in the flow path have at most limited affect towards and to the measuring space.

[0070] In a preferred embodiment, for one or more of the measuring sections the first subsection of their respective gap section is directly adjacent to the flow path, i.e., extends outwards from the flow path along a substantially radial direction (e.g. a direction substantially radial to a transporting direction of the fluid when being transported along the flow path).

[0071] Hence, the measuring section can have a simple but effective layout.

[0072] Preferably, the first subsection partially or completely surrounds the flow path with respect to the circumferential direction, wherein it is further preferred that the first subsection has an annular or partially annular geometric shape.

[0073] Hence, the - first subsection - and thus the initial part of the communication section, can be effectively provided, as needed.

[0074] In a preferred embodiment, for one or more of the measuring sections the one or more second subsections of their respective gap section extend from a downstream portion of the first subsection along an substantially axial direction (e.g. a direction substantially axial or parallel to a transporting direction of the fluid when being transported along the flow path) towards the measuring space of the respective measuring section.

[0075] Hence, influences from the flow path (e.g. pressure variations) can be effectively leveled out towards the measuring space.

[0076] Preferably, the axial direction, the radial direction and the circumferential direction form a cylindrical coordinate system, wherein the axial direction preferably runs parallel to a transporting direction of the fluid at the respective upstream or downstream position at which the respective communication section communicates with the flow path, and the radial and circumferential direction are preferably orthogonal to said axial direction.

[0077] In a preferred embodiment, for one or more of the measuring sections the one or more second subsections of their respective gap section are arranged at defined positions along the circumferential direction, spaced apart from each other.

[0078] In other words, the one or more second subsections are distributed over a circumference surrounding the flow path.-

[0079] Hence, defined - kind of - ports extending form the (annular) first subsection can be provided in an easy but effective way.

[0080] Preferably, a circumferential width of the one or more second subsections is in a range from ’ 360, with r being a radial distance of the one or more second subsections to a center line of the flow path, with respect to the radial direction. The case of ’360thereby corresponds to a case in which one second subsection surrounds the complete circumference.

[0081] In a preferred embodiment, for one or more of the measuring sections the one or more second subsections are arranged so as to not coincide with a position of a connecting port (like the hydraulic connection channel), via which the measuring space of the respective measuring section is connected to the respective sensor unit , with respect to the circumferential direction.

[0082] In that manner, fluid flowing from the gap section into the measuring space has sufficient time to calm down before it reaches the connecting port, such that, for example, falsifying turbulences at the connecting port can be reduced.

[0083] In a preferred embodiment, for one or more of the one or the plurality of measuring units, an inlay element and a respectively adapted receiving section of the inlet or of the outlet together form the respective measuring section.

[0084] This allows a less complex construction to provide the spatially separated measuring space.

[0085] Preferably, the receiving section is designed as a recess of an inner contour of the inlet or of the outlet, respectively, and the inlay element is preferably designed as a ring element fitting into the receiving section.

[0086] Preferably, the first and / or the second measuring unit comprise measuring sections realized according to one or more of the afore-described configurations.

[0087] In a preferred embodiment the centrifugal pump further comprises an inlet pipe, which is mechanically connected to the inlet, preferably by means of a flange connection or by means of a fit connection, in particular by means of an interference fit connection.

[0088] This allows an easy setup of the centrifugal pump, by means of which, for example, an easy access to the inlet or to the impeller can be realized, for example for maintenance purposes. The inlet pipe thereby offers the possibility to provide an interface for connecting the pump with a fluid network spatially separated from the pump body.

[0089] Preferably, an end section of the inlet pipe and an end section of the inlet together form a measuring section of one of the one or the plurality of measuring units, such that the respective measuring section is provided at an interface between the inlet pipe and the inlet of the pump body. This allows to implement a respective measuring space without the need of further components, but by utilizing existing components and providing the measuring space at their interface.

[0090] Preferably, aforesaid measuring section formed by the inlet pipe and the end section of the inlet is the measuring section of one of the first and second measuring units.

[0091] In a preferred embodiment, the centrifugal pump further comprises an outlet pipe, which is mechanically connected to the outlet, preferably by means of a flange connection or by means of a fit connection, in particular by means of an interference fit connection.

[0092] Similarly to the inlet pipe, this allows an easy setup of the centrifugal pump, by means of which, for example, an easy access to the outlet or to the impeller can be realized, for example for maintenance purposes. The outlet pipe thereby offers the possibility to provide an interface for connecting the pump with a fluid network spatially separated from the pump body.

[0093] Preferably, an end section of the outlet pipe and an end section of the outlet together form a respective measuring section of one of the one or the plurality of measuring units, such that the respective measuring section is provided at an interface between the outlet pipe and the outlet of the pump body.

[0094] This allows to implement a respective measuring space without the need of further components, but by utilizing existing components and providing the measuring space at their interface.

[0095] Preferably, aforesaid measuring section formed by the inlet pipe and the end section of the inlet is the measuring section of one of the first and second measuring units.

[0096] In a preferred embodiment, the impeller housing comprises a volute section, which is located between the impeller and the outlet with respect to the flow path, wherein a respective measuring section of one of the one or the plurality of measuring units is arranged at the volute section.

[0097] This allows a reliable measurement more or less directly at the output interface of the impeller, from which the fluid pushed radially outwards due to the rotation of the impeller.

[0098] Preferably, the one of the one or the plurality of measuring units arranged at the volute section is the first or second measuring unit. More preferably, said measuring unit is a third measuring unit. Preferably, the impeller housing further comprises a cover section mechanically connected to the volute section, such that the cover section and the volute section together enclose the impeller.

[0099] This allows an easy access to the interior of the impeller housing, for example for mounting or maintenance purposes.

[0100] Preferably, an end section of the cover section and an end section of the volute section together form the respective measuring section of the one of the one or the plurality of measuring units arranged at the volute section, such that the respective measuring section is provided at an interface between the cover section and the volute section.

[0101] This allows to implement a respective measuring space without the need of further components, but by utilizing existing components and providing the measuring space at their interface.

[0102] According to a second aspect of the invention, a pump system is provided, in particular a booster system. The pump system comprises K hydraulically connected centrifugal pumps, with integer K>2, from which L centrifugal pumps are centrifugal pumps according to the first aspect or according to one of its preferred embodiments. For integer L, L>2 and L<K holds.

[0103] Preferably, the K centrifugal pumps are designed as in-line centrifugal pumps whose flow paths are arranged in-line to form a connected system flow path.

[0104] Preferably, the first pump within the in-line connected flow path is one of the K centrifugal pumps and comprises one measuring unit at an upstream position relative to its impeller, and the last pump within the in-line connected flow path is also one of the K centrifugal pumps and comprises one measuring unit at a downstream position relative to its impeller.

[0105] By means of that, a pump system can be provided for which an accurate measurement of the overall differential pressure can be achieved based on the measurements at the first and the last centrifugal pump.

[0106] Brief Description of the Drawings

[0107] Further aspects and advantages of the invention as well as specific examples of the aforementioned embodiments are described below with reference to the drawings shown in the accompanying figures. Fig. 1A shows a cross-section of a first example of the centrifugal pump according to the invention in a plan view.

[0108] Fig. 1B shows an exploded drawing of the first example of the centrifugal pump in a perspective view.

[0109] Fig. 1C shows an enlarged cutout from the cross-section shown in Fig. 1A in an area of a first measuring unit.

[0110] Fig. 1D shows an enlarged cutout from the cross-section shown in Fig. 1A in an area of a second measuring unit.

[0111] Fig. 1E shows an enlarged cutout from the cross-section shown in Fig. 1A in an area of a third measuring unit.

[0112] Fig. 2A shows a cross-section of a second example of the centrifugal pump according to the invention in a plan view.

[0113] Fig. 2B shows an exploded drawing of the second example of the centrifugal pump in a perspective view.

[0114] Fig. 3A shows a third example of the centrifugal pump according to the invention, isometrically cut, in a perspective view.

[0115] Fig. 3B shows an enlarged cutout from the isometric cut shown in Fig. 3A in an area of a second measuring unit.

[0116] Fig. 3C shows an enlarged cutout from the isometric cut shown in Fig. 3A in an area of a first measuring unit.

[0117] Fig. 4A shows a fourth example of the centrifugal pump according to the invention, isometrically cut, in a perspective view.

[0118] Fig. 4B shows an enlarged cutout from the isometric cut shown in Fig. 4A in an area of a first measuring unit.

[0119] Fig. 4C shows an inlet pipe of the centrifugal pump shown in Fig. 4A in a perspective view.

[0120] Fig. 4D shows a base part of the centrifugal pump shown in Fig. 4A, isometrically cut, in a perspective view. Fig. 5A shows a fifth example of the centrifugal pump according to the invention, isometrically cut, in a perspective view.

[0121] Fig. 5B shows an enlarged cutout from the isometric cut shown in Fig. 5A in an area of a first measuring unit.

[0122] Fig. 5C shows a part of another isometric cut of the centrifugal pump 1 shown in Fig. 5A in the area of a first measuring unit.

[0123] Fig. 5D shows an inlet pipe of the centrifugal pump shown in Fig. 5A, isometrically cut, in a perspective view.

[0124] Fig. 5E shows a base part of the centrifugal pump shown in Fig. 5A, isometrically cut, in a perspective view.

[0125] Fig. 6A shows a sixth example of the centrifugal pump according to the invention, isometrically cut, in a perspective view.

[0126] Fig. 6B shows an enlarged cutout from the isometric cut shown in Fig. 6A in an area of a first measuring unit.

[0127] Fig. 6C shows a part of another isometric cut of the centrifugal pump shown in Fig. 6A in the area of a first measuring unit.

[0128] Fig. 6D shows an inlet pipe of the centrifugal pump shown in Fig. 6A, isometrically cut, in a perspective view.

[0129] Fig. 6E shows a base part of the centrifugal pump shown in Fig. 6A, isometrically cut, in a perspective view.

[0130] Fig. 7A shows a fifth example of the centrifugal pump according to the invention, isometrically cut, in a perspective view.

[0131] Fig. 7B shows an enlarged cutout from the isometric cut shown in Fig. 7A in an area of a first measuring unit.

[0132] Fig. 7C shows a part of another isometric cut of the centrifugal pump shown in Fig. 5A in the area of a first measuring unit.

[0133] Fig. 7D shows an inlet pipe of the centrifugal pump shown in Fig. 7A, isometrically cut, in a perspective view. Fig. 7E shows a base part of the centrifugal pump shown in Fig. 7A, isometrically cut, in a perspective view.

[0134] Detailed Description of the Drawings

[0135] Fig. 1A shows a cross-section of a first example of the centrifugal pump 1 according to the invention in a plan view. Fig. 1B shows a respective exploded drawing of the first example of the centrifugal pump 1 in a perspective view.

[0136] Fig. 1C to 1E show enlarged cutouts from the cross-section shown in Fig. 1A in an area of a first measuring unit 31, a second measuring unit 32 and a third measuring unit 33, respectively.

[0137] Fig. 1A to 1E will be described together in the following.

[0138] The centrifugal pump 1 is designed for pumping a fluid and comprises a pump body 10, having an impeller housing 12, an inlet 11 and an outlet 13, which together define a flow path for the fluid.

[0139] Further, the pump 1 comprises an impeller 20, which is rotatably supported within the impeller housing 12, for transporting the fluid from the inlet 11 along the flow path to the outlet 13.

[0140] Preferably, the impeller 20 is supported by an impeller shaft 21, which is rotatably supported by a shaft support 22, which is preferably connected to the impeller housing 12.

[0141] Preferably, the impeller housing 12 comprises a base part 121.

[0142] Preferably, the inlet 11 and / or the outlet 13 are formed integrally together with said base part 121 of the impeller housing 12, as shown in Fig. 1A.

[0143] Preferably, the impeller housing 12 comprises a volute section 122, which is located between the impeller 20 and the outlet 13 with respect to the flow path. In particular, the volute section 122 is formed as part of the base part 121.

[0144] Preferably, the impeller housing 12 comprises a cover section 123 which is mechanically connected to the volute section 122, such that the cover section 123 and the volute section 122 together enclose the impeller 20, as shown in Fig. 1A.

[0145] Preferably, the centrifugal pump 1 further comprises an inlet pipe 14a, which is mechanically connected to the inlet 11, as shown in Fig. 1A, preferably by means of a flange connection or by means of a fit connection, in particular by means of an interference fit connection. Preferably, the inlet pipe 14a has an arched shape, such that an inline arrangement of the pump 1 can be provided, i.e. a flow direction of the fluid flowing into the inlet pipe 14a and flow direction of the fluid flowing out of the outlet 13 are substantially parallel to each other or are both parallel to a horizontal plane, which runs inclined, in particular orthogonal, to a rotational axis of the impeller 20 (cf. Fig. 1A).

[0146] Further, the pump 1 comprises a fluid measuring device for measuring a pressure of the fluid, wherein the fluid measuring device comprises one or a plurality of measuring units 31, 32, 33, each being arranged to measure the pressure of the fluid at a respective upstream or downstream position of the flow path relative to the impeller 20.

[0147] Preferably, the fluid measuring device comprises three measuring units 31, 32, 33, such that the first example comprises a first measuring unit 31, which is in particular arranged to measure the pressure of the fluid at an upstream position relative to the impeller 20, a second measuring unit 32 and a third measuring unit 33, which are both in particular arranged to measure the pressure of the fluid at a downstream position relative to the impeller 20.

[0148] A more detailed view of the measuring units 31, 32, 33 is shown in the cutouts in Fig. 1C to 1E.

[0149] Each of the measuring units 31, 32, 33 comprises a sensor unit 311, 321 and a related measuring section 312, 322, 332 enclosing a respective measuring space 313, 323, 333. A sensor unit of the third measuring unit 33 (third sensor unit) is not shown in Fig. 1A to 1E.

[0150] Preferably, the impeller housing 12 comprises one or more sensor ports 124 via which the sensor units 321, 321 can be hydraulically connected to the respective measuring spaces 313? 323. The sensor units 321, 321 can for example be connected to said sensor ports 124 or be inserted into them.

[0151] Each measuring space 313, 323, 333 is spatially separated from the flow path and arranged to hydraulically communicate through a communication section 314, 324, 334 of the respective measuring section 312, 322, 332 with an upstream position or a downstream position of the flow path relative to the impeller 20, such that the measuring space 313, 323, 333 is filled with fluid from the flow path when the fluid is transported by the impeller 20 along the flow path.

[0152] Each sensor unit 311, 321 is arranged to measure the pressure of the fluid inside the measuring space 313, 323, 333 of the related measuring section 312, 322, 332. Preferably, the first sensor unit 311 of the first measuring unit 31 and the second sensor unit 321 of the second measuring unit 32 are designed together in the form of a differential pressure sensor, wherein the differential pressure sensor is configured to measure a differential pressure between the first and second measuring space 313, 323.

[0153] In other words, the first sensor unit 311 and the second sensor unit 321 together represent a differential pressure sensor.

[0154] However, the first and second sensor units 311, 321 could also be provided as separate components.

[0155] In the following, the respective measuring units 31, 32, 33 are described in detail with respect to Fig. 1C to 1E.

[0156] Fig. 1C shows a cutout in the area of the first measuring unit 31, which comprises a first measuring section 312, enclosing the respective first measuring space 313, which is spatially separated from the flow path and arranged to hydraulically communicate through a first communication section 314 of the first measuring section 312, such that the first measuring space 313 is filled with fluid from the flow path when the fluid is transported by the impeller 20 along the flow path.

[0157] A first sensor unit 311 (not shown in Fig. 1C) is arranged to measure the pressure of the fluid inside the first measuring space 313 of the first measuring section 312.

[0158] Preferably, an end section 312-1 of the inlet pipe 14a and an end section 312-2 of the inlet 11 together form the first measuring section 312, such that the first measuring section 312 is provided at an interface between the inlet 11 pipe and the inlet 11 of the pump body 10, as shown in Fig. 1A and 1C.

[0159] Preferably, the interface comprises one or more sealing members 15, which are preferably designed as O-rings or as piston sealings.

[0160] Preferably, the first measuring space 313 enclosed by the first measuring section 312 is ring-shaped or has the geometric shape of a hollowed generalized cylinder, which is circumferentially arranged around the flow path. In particular, the first measuring space 313 has substantially the shape of a ring or a hollowed circular cylinder, as exemplary shown in Fig. 1C.

[0161] Preferably, the first communication section 314 of the first measuring section 312 comprises a plurality of communications channels, wherein each communication channel is preferably formed as a through-hole, wherein the plurality of channels are preferably evenly distributed along the first measuring section 312.

[0162] Preferably, the first communication section 314 is formed within the end section 312-1 of the inlet pipe 14a, as shown in Fig. 1C.

[0163] Preferably, the plurality of communication channels extend in a direction radial to a transporting direction of the fluid when being transported along the flow path, as shown in Fig. 1C.

[0164] Fig. 1D shows a cutout in the area of the second measuring unit 32, which comprises a second measuring section 322, enclosing the respective second measuring space 323, which is spatially separated from the flow path and arranged to hydraulically communicate through a second communication section 324 of the second measuring section 322, such that the second measuring space 323 is filled with fluid from the flow path when the fluid is transported by the impeller 20 along the flow path.

[0165] A second sensor unit 321 (not shown in Fig. 1D) is arranged to measure the pressure of the fluid inside the second measuring space 323 of the second measuring section 322.

[0166] Preferably, the second measuring section 322 is formed by an inlay element 322-2 together with a respectively adapted receiving section 322-1 of the outlet 13, as shown in Fig. 1D.

[0167] Preferably, the receiving section 322-1 is designed as a recess of an inner contour of the outlet 13, respectively, and the inlay element 322-2 is preferably designed as a ring element fitting into the receiving section 322-1, as shown in Fig. 1A and 1D.

[0168] Preferably, the second communication section 324 of the second measuring section 322 comprises a plurality of communications channels, wherein each communication channel is preferably formed as a through-hole, wherein the plurality of channels are preferably evenly distributed along the second measuring section 322.

[0169] Preferably, the second communication section 324 is formed within the inlay element 322-2, as shown in Fig. 1D.

[0170] Preferably, the plurality of communication channels extend in a direction radial to a transporting direction of the fluid when being transported along the flow path, as shown in Fig. 1D.

[0171] Preferably, the second measuring space 323 enclosed by the second measuring section 322 has an annular or ring shape (i.e. is ring-shaped) or has the geometric shape of a hollowed generalized cylinder, which is circumferentially arranged around the flow path. In particular, the second measuring space 323 has substantially the shape of a ring or a hollowed circular cylinder, as exemplary shown in Fig. 1D.

[0172] Fig. 1E shows a cutout in the area of the third measuring unit 33, which comprises a third measuring section 332, enclosing the respective third measuring space 333, which is spatially separated from the flow path and arranged to hydraulically communicate through a third communication section 334 of the third measuring section 332, such that the third measuring space 333 is filled with fluid from the flow path when the fluid is transported by the impeller 20 along the flow path.

[0173] A third sensor unit (not shown) is arranged to measure the pressure of the fluid inside the third measuring space 333 of the third measuring section 332.

[0174] Preferably, an end section 332-1 of the cover section 123 and an end section 332-2 of the volute section 122 together form the third measuring section 332 arranged at the volute section 122, such that the third measuring section 332 is provided at an interface between the cover section 123 and the volute section 122.

[0175] Preferably, the interface comprises one or more sealing members 15, which are preferably designed as O-rings or as piston sealings.

[0176] Preferably, the third communication section 334 of the third measuring section 332 comprises a plurality of communications channels, wherein each communication channel is preferably formed as a through-hole, wherein the plurality of channels are preferably evenly distributed along the third measuring section 332.

[0177] Preferably, the third communication section 334 is formed within the end section 332-1 of the cover section 123, as shown in Fig. 1E.

[0178] Preferably, the of communication channels extend in a direction radial to a transporting direction of the fluid when being transported along the flow path, as shown in Fig. 1E.

[0179] Preferably, the third measuring space 333 enclosed by the third measuring section 332 has an annular or ring shape (i.e. is ring-shaped) or has the geometric shape of a hollowed generalized cylinder, which is circumferentially arranged around the flow path. In particular, the second third measuring space 333 has substantially the shape of a ring or a hollowed circular cylinder, as exemplary shown in Fig. 1E. By means of the described measuring units 31, 32, 33, the pressure of the fluid is not measured directly within the flow path itself, but within the spatially separated, flow-calmed measuring spaces 313, 323, 333, such that the amount of measurement falsifying influences present within the provided measuring space 313, 323, 333 is less compared to the flow path.

[0180] Consequently, a stabilized measuring environment is provided within said measuring spaces 313, 323, 333 so as to reduce measurement errors of the sensor units 311, 321.

[0181] In that manner, the actual measuring points can be moved closer to the impeller 20 without leading to a falsification of the measurement results, such that an accurate measurement of the fluid’s pressure can be realized close to the pump’s ‘heart’, namely the impeller 20.

[0182] It shall be noted, that the pump 1 according to the first example could also be amended so as to solely comprise one or two of the afore-described measuring units 31, 32, 33. Further, the first example could also be amended so as to comprise more than three measuring units.

[0183] Fig. 2A shows a cross-section of a second example of the centrifugal pump 1 according to the invention in a plan view. Fig. 2B shows a respective exploded drawing of the second example of the centrifugal pump 1 in a perspective view.

[0184] The pump 1 according to the second example differs from the pump according to the first example solely by the design of the inlet pipe 14b and by the fact, that it does not comprise a third measuring unit at the volute section 122.

[0185] At this point, it is refrained from repeating the description of the substantially similar parts of the pump 1.

[0186] Preferably, the centrifugal pump 1 comprises an inlet pipe 14b, which is mechanically connected to the inlet 11, as exemplary shown in Fig. 2A, preferably by means of a flange connection or by means of a fit connection, in particular by means of an interference fit connection.

[0187] Preferably, the inlet pipe 14b has a straight shape, such that an end-suction arrangement of the pump 1 can be provided, i.e. a flow direction of the fluid flowing into the inlet pipe 14b and flow direction of the fluid flowing out of the outlet 13 are substantially inclined relative to each other, in particular orthogonal to each other (cf. Fig. 2A).

[0188] Preferably, the fluid measuring device comprises two measuring units 31, 32, such that the second example comprises a first measuring unit 31, which is in particular arranged to measure the pressure of the fluid at an upstream position relative to the impeller 20 and a second measuring unit 32, arranged to measure the pressure of the fluid at a downstream position relative to the impeller 20.

[0189] Preferably, the first and second measuring units 31, 32 are designed identical or substantially similar to the first and second measuring units 31, 22 according to the first example (cf. Fig. 1C and 1D).

[0190] Compared to the pump 1 according to the first example, the pump 1 according to the second example comprises a sealing member 15 in the interface between the cover section 123 and the volute section 122 instead of a third measuring unit.

[0191] Fig. 3A shows a third example of the centrifugal pump 1 according to the invention, isometrically cut, in a perspective view.

[0192] Fig. 3B and 3C show enlarged cutouts from the isometric cut shown in Fig. 3A in an area of a second measuring unit 32 and a first measuring unit 31, respectively.

[0193] Fig. 3A to 3C will be described together in the following.

[0194] The centrifugal pump 1 is designed for pumping a fluid and comprises a pump body 10, having an impeller housing 12, an inlet 11 and an outlet 13, which together define a flow path for the fluid.

[0195] Further, the pump 1 comprises an impeller 20, which is rotatably supported within the impeller housing 12, for transporting the fluid from the inlet 11 along the flow path to the outlet 13.

[0196] Preferably, the impeller 20 is supported by an impeller shaft 21, which is rotatably supported by a shaft support, which is preferably connected to the impeller housing 12.

[0197] Preferably, the impeller housing 12 comprises a base part 121.

[0198] Preferably, the inlet 11 and / or the outlet 13 are formed integrally together with said base part 121 of the impeller housing 12.

[0199] Preferably, the impeller housing 12 comprises a volute section 122, which is located between the impeller 20 and the outlet 13 with respect to the flow path. In particular, the volute section 122 is formed as part of the base part 121. Preferably, the impeller housing 12 comprises a cover section 123 which is mechanically connected to the volute section 122, such that the cover section 123 and the volute section 122 together enclose the impeller 20, as exemplary shown in Fig. 3A.

[0200] Preferably, the centrifugal pump 1 further comprises an inlet pipe 14a, which is mechanically connected to the inlet 11, as shown in Fig. 3A, preferably by means of a flange connection or by means of a fit connection, in particular by means of an interference fit connection.

[0201] Preferably, the inlet pipe 14a has a bended shape, such that an inline arrangement of the pump 1 can be provided, i.e. a flow direction of the fluid flowing into the inlet pipe 14a and flow direction of the fluid flowing out of the outlet 13 are substantially parallel to each other or are both parallel to a horizontal plane, which runs inclined, in particular orthogonal, to a rotational axis of the impeller 20 (cf. Fig. 3A).

[0202] Further, the pump 1 comprises a fluid measuring device for measuring a pressure of the fluid, wherein the fluid measuring device comprises one or a plurality of measuring units 31, 32, each being arranged to measure the pressure of the fluid at a respective upstream or downstream position of the flow path relative to the impeller 20.

[0203] Preferably, the fluid measuring device comprises two measuring units 31, 32, such that the third example comprises a first measuring unit 31, which is in particular arranged to measure the pressure of the fluid at an upstream position relative to the impeller 20 and a second measuring unit 32, which is arranged to measure the pressure of the fluid at a downstream position relative to the impeller 20.

[0204] A more detailed view of the measuring units 31, 32 is shown in the cutouts in Fig. 3B and 3C.

[0205] Each of the measuring units 31, 32 comprises a sensor unit (not shown) and a related measuring section 312, 322 enclosing a respective measuring space 313, 323.

[0206] Preferably, the impeller housing 12 comprises one or more sensor ports 124 via which the sensor units can be hydraulically connected to the respective measuring spaces 313, 323. The sensor units can for example be connected to said sensor ports 124 or be inserted into them.

[0207] Each measuring space 313, 323 is spatially separated from the flow path and arranged to hydraulically communicate through a communication section 314, 324 of the respective measuring section 312, 322 with an upstream position or a downstream position of the flow path relative to the impeller 20, such that the measuring space 313, 323 is filled with fluid from the flow path when the fluid is transported by the impeller 20 along the flow path.

[0208] Each sensor unit is arranged to measure the pressure of the fluid inside the measuring space 313, 323 of the related measuring section 312, 322.

[0209] In the following, the respective measuring units 31, 32 are described with respect to Fig. 3B and 3C.

[0210] Fig. 3B shows a cutout in the area of the second measuring unit 32, which comprises a second measuring section 322, enclosing the respective second measuring space 323, which is spatially separated from the flow path and arranged to hydraulically communicate through a second communication section 324 of the second measuring section 322, such that the second measuring space 323 is filled with fluid from the flow path when the fluid is transported by the impeller 20 along the flow path.

[0211] A second sensor unit (not shown) is arranged to measure the pressure of the fluid inside the second measuring space 323 of the second measuring section 322.

[0212] Preferably, the second sensor unit is hydraulically connected to the second measuring space 323 by means of a second hydraulic connection channel 325, which is preferably formed as vacancy within the pump body 10, as shown in Fig. 3B.

[0213] Preferably, the second connection channel 325 extends until a sensor port 124 at which the second sensor unit can be provided.

[0214] Preferably, the second measuring section 322 is formed by an inlay element 322-2 together with a respectively adapted receiving section 322-1 of the outlet 13, as shown in Fig. 3B.

[0215] Preferably, the receiving section 322-1 is designed as a recess of an inner contour of the outlet 13, respectively, and the inlay element 322-2 is preferably designed as a ring element fitting into the receiving section 322-1, as shown in Fig. 3B.

[0216] Preferably, the second communication section 324 of the second measuring section 322 comprises a plurality of communications channels, wherein each communication channel is preferably formed as a through-hole, wherein the plurality of channels are preferably evenly distributed along the second measuring section 322.

[0217] Preferably, the second communication section 324 is formed within the inlay element 322-2, as shown in Fig. 3B. Preferably, the plurality of communication channels extend in a direction radial to a transporting direction of the fluid when being transported along the flow path, as shown in Fig. 3B.

[0218] Preferably, the second measuring space 323 enclosed by the second measuring section 322 has an annular or ring shape (i.e. is ring-shaped) or has the geometric shape of a hollowed generalized cylinder, which is circumferentially arranged around the flow path. In particular, the second measuring space 323 has substantially the shape of a ring or a hollowed circular cylinder, as exemplary shown in Fig. 3B.

[0219] Fig. 3C shows a cutout in the area of the first measuring unit 31, which comprises a first measuring section 312, enclosing the respective first measuring space 313, which is spatially separated from the flow path and arranged to hydraulically communicate through a first communication section 314 of the first measuring section 312, such that the first measuring space 313 is filled with fluid from the flow path when the fluid is transported by the impeller 20 along the flow path.

[0220] A first sensor unit (not shown) is arranged to measure the pressure of the fluid inside the first measuring space 313 of the first measuring section 312.

[0221] Preferably, the first sensor unit is hydraulically connected to the first measuring space 313 by means of a first hydraulic connection channel 315, which is preferably formed as vacancy within the pump body 10, as shown in Fig. 3C.

[0222] Preferably, the first connection channel 315 extends until a sensor port 124 at which the first sensor unit can be provided.

[0223] Preferably, an end section 312-1 of the inlet pipe 14a and an end section 312-2 of the inlet 11 together form the first measuring section 312, such that the first measuring section 312 is provided at an interface between the inlet 11 pipe and the inlet 11 of the pump body 10, as shown in Fig. 3A and 3C.

[0224] Preferably, the interface comprises one or more sealing members 15, which are preferably designed as O-rings.

[0225] Preferably, the first measuring space 313 enclosed by the first measuring section 312 has an annular or ring shape (i.e. is ring-shaped) or has the geometric shape of a hollowed generalized cylinder, which is circumferentially arranged around the flow path. In particular, the first measuring space 313 has substantially the shape of a ring or a hollowed circular cylinder, as exemplary shown in Fig. 3C. Preferably, the first communication section 314 of the first measuring section 312 comprises a plurality of communications channels, wherein each communication channel is preferably formed as a through-hole, wherein the plurality of channels are preferably evenly distributed along the first measuring section 312.

[0226] Preferably, the first communication section 314 is formed within the end section 312-1 of the inlet pipe 14a, as shown in Fig. 3C.

[0227] Preferably, the plurality of communication channels extend in a direction radial to a transporting direction of the fluid when being transported along the flow path, as shown in Fig. 3C.

[0228] Preferably, the first and second connection channel 315, 325 are formed by a single measuring channel connecting the measuring space 313 of the first measuring unit 31 and the measuring space 323 of the second measuring unit 32, wherein the measuring channel preferably extends straight through the pump body 10, as exemplary shown in Fig. 3A.

[0229] Preferably, the measuring channel also comprises a sensor port 124 for connecting it with the respective sensor units.

[0230] Preferably, the first sensor unit of the first measuring unit 31 and the second sensor unit of the second measuring unit 32 are designed together to form a differential pressure sensor, in particular to be inserted or to be connected to the sensor port 124, wherein the differential pressure sensor is configured to measure a differential pressure between the first and second measuring space 313, 323.

[0231] In other words, the first sensor unit and the second sensor unit together represent a differential pressure sensor.

[0232] By means of the described measuring units 31, 32, the pressure of the fluid is not measured directly within the flow path itself, but within the spatially separated, flow-calmed measuring spaces 313, 323, such that the amount of measurement falsifying influences present within the provided measuring space 313, 323 is less compared to the flow path.

[0233] Consequently, a stabilized measuring environment is provided within said measuring spaces 313, 323, so as to reduce measurement errors of the sensor units.

[0234] In that manner, the actual measuring points can be moved closer to the impeller 20 without leading to a falsification of the measurement results, such that an accurate measurement of the fluid’s pressure can be realized close to the pump’s ‘heart’, namely the impeller 20. Fig. 4A shows a fourth example of the centrifugal pump 1 according to the invention, isometrically cut, in a perspective view.

[0235] Fig. 4B shows an enlarged cutout from the isometric cut shown in Fig. 4A in an area of a first measuring unit 31.

[0236] Fig. 4C shows an inlet pipe 14a of the centrifugal pump 1 shown in Fig. 4A in a perspective view.

[0237] Fig. 4D shows a base part 121 of the centrifugal pump 1 shown in Fig. 4A, isometrically cut, in a perspective view.

[0238] Fig. 4A to 4D will be described together in the following.

[0239] The centrifugal pump 1 is designed for pumping a fluid and comprises a pump body 10, having an impeller housing 12, an inlet 11 and an outlet 13, which together define a flow path for the fluid.

[0240] Further, the pump 1 comprises an impeller 20, which is rotatably supported within the impeller housing 12, for transporting the fluid from the inlet 11 along the flow path to the outlet 13.

[0241] Preferably, the impeller 20 is supported by an impeller shaft 21, which is rotatably supported by a shaft support, which is preferably connected to the impeller housing 12.

[0242] Preferably, the impeller housing 12 comprises a base part 121.

[0243] Preferably, the inlet 11 and / or the outlet 13 are formed integrally together with said base part 121 of the impeller housing 12.

[0244] Preferably, the impeller housing 12 comprises a volute section 122, which is located between the impeller 20 and the outlet 13 with respect to the flow path. In particular, the volute section 122 is formed as part of the base part 121.

[0245] Preferably, the impeller housing 12 comprises a cover section 123 which is mechanically connected to the volute section 122, such that the cover section 123 and the volute section 122 together enclose the impeller 20, as exemplary shown in Fig. 4A.

[0246] Preferably, the centrifugal pump 1 further comprises an inlet pipe 14a, which is mechanically connected to the inlet 11, as shown in Fig. 4A, preferably by means of a flange connection or by means of a fit connection, in particular by means of an interference fit connection. Preferably, the inlet pipe 14a has a bended shape, such that an inline arrangement of the pump 1 can be provided, i.e. a flow direction of the fluid flowing into the inlet pipe 14a and flow direction of the fluid flowing out of the outlet 13 are substantially parallel to each other or are both parallel to a horizontal plane, which runs inclined, in particular orthogonal, to a rotational axis of the impeller 20 (cf. Fig. 4A).

[0247] Further, the pump 1 comprises a fluid measuring device for measuring a pressure of the fluid, wherein the fluid measuring device comprises one or a plurality of measuring units 31, each being arranged to measure the pressure of the fluid at a respective upstream or downstream position of the flow path relative to the impeller 20.

[0248] Within the fourth example solely a first measuring unit 31 is shown, which is in particular arranged to measure the pressure of the fluid at an upstream position relative to the impeller 20. Additionally, a second measuring unit might be provided so as to measure the pressure of the fluid at a downstream position relative to the impeller 20.

[0249] A more detailed view of parts of the first measuring unit 31 is shown in the cutout in Fig. 4B.

[0250] The first measuring unit 31 comprises a first sensor unit 311 and a related first measuring section 312 enclosing a first measuring space 313.

[0251] Preferably, the impeller housing 12 comprises one or more sensor ports 124 via which the first sensor unit 311 can be hydraulically connected to the first measuring space 313. The sensor unit 311 can for example be connected to one of the sensor ports 124 or be inserted into them.

[0252] The first measuring space 313 is spatially separated from the flow path and arranged to hydraulically communicate through a first communication section 314 of the first measuring section 312 with an upstream position of the flow path relative to the impeller 20, such that the first measuring space 313 is filled with fluid from the flow path when the fluid is transported by the impeller 20 along the flow path.

[0253] The first sensor unit 311 is arranged to measure the pressure of the fluid inside the first measuring space 313 of the first measuring section 312, wherein the first measuring space 313 is preferably connected to one of the sensor ports 124 by means of a first hydraulic connection channel 315, particularly formed within the base part 121.

[0254] Preferably, an end section 312-1 of the inlet pipe 14a and an end section 312-2 of the inlet 11 together form the first measuring section 312, such that the first measuring section 312 is provided at an interface between the inlet pipe 14a and the inlet 11 of the pump body

[0255] 10, as shown in Fig. 4B, which is also referred to as an inlet interface measuring section 312.

[0256] Preferably, the interface comprises one or more sealing members 15, which are preferably designed as O-rings.

[0257] Preferably, the first measuring space 313 enclosed by the first measuring section 312 has an annular or ring shape (i.e. is ring-shaped) or has the geometric shape of a hollowed generalized cylinder, which is circumferentially arranged around the flow path. In particular, the first measuring space 313 has substantially the shape of a ring or a hollowed circular cylinder.

[0258] Preferably, the first communication section 314 of the first measuring section 312 is formed as a gap section within the pump body 10, with the gap section being circumferentially arranged around the flow path, so as to partially or completely surround the flow path with respect to a circumferential direction, wherein the first communication section 314 particularly comprises a first subsection 314-1 and one or more second subsections 314-2, connected in series to the first subsection 314-1. The respective subsections 314-1, 314-2 may be connected by an angled or bent section; i.e. extending in a defined angled orientation with respect to each other, e.g., orthogonally to each other.

[0259] Preferably, the first subsection 314-1 is directly adjacent to the flow path and is more preferably defined by a first contour surface 312-11 of the end section 312-1 of the inlet pipe 14a and a first contour surface 312-21 of the end section 312-2 of the inlet 11. In that manner, the first subsection 314-1 is formed between said end-section 312-1, 312-2.

[0260] However, the first subsection 314-1 can also be designed as being completely formed within one of said end-sections 312-1, 312-2.

[0261] Preferably, the first subsection 314-1 extends outwards from the flow path along a radial direction, wherein the first subsection 314-1 might partially or completely surround the flow path with respect to the circumferential direction.

[0262] In case of the fourth example shown in Fig. 4A to 4D, the first subsection 314-1 completely surrounds the flow path and particularly has an annular shape.

[0263] Preferably, the first contour surface 312-11 of the end section 312-1 of the inlet pipe 14a and / or the first contour surface 312-21 of the end section 312-2 of the inlet 11 extend in a radial and circumferential direction, as exemplary shown in Fig. 4A to 4C, wherein said directions are part of a cylindrical coordinate system, in which the transport direction of the fluid preferably corresponds to an axial direction of the cylindrical coordinate system. In order to connect the first subsection 314-1 with the first measuring space 313, the first communication section 314 comprises said one or more second subsections 314-2, connected in series to the first subsection 314-1, thus, in between the first subsection 314-1 and the first measuring space 313.

[0264] In case of the fourth example shown in Fig. 4A to 4D, the first communication section 314 comprises just one second subsection 314-2, which preferably extends from a downstream portion of the first subsection 314-1 along the axial direction towards the first measuring space 313.

[0265] Preferably, the one second subsection 314-2 extends over a whole circumference, thus, completely surrounding the flow path and preferably having the geometric shape of a ring or of a generalized hollowed cylinder.

[0266] Preferably, the one second subsection 314-2 is defined by a respective second contour surface 312-12 of the end section 312-1 of the inlet pipe 14a and a respective second contour surface 312-22 of the end section 312-2 of the inlet 11 of the pump body 10.

[0267] In particular, said second contour surfaces 312-12, 312-22 have the shape of cylindrical surfaces, in between which the fluid is capable of flowing from the downstream portion of the first subsection 314-1 to the first measuring space 313 (cf. Fig. 4B).

[0268] The foregoing realization of a gap section as first communication section 314 of the first measuring section 312 is not limited to the first measuring unit 31, but can also be applied to other measuring units of the centrifugal pump 1, such as a measuring unit located at the outlet 13 or at the volute section 122.

[0269] By means of the described measuring unit 31, the pressure of the fluid is not measured directly within the flow path itself, but within the spatially separated, flow-calmed measuring spaces 313, such that the amount of measurement falsifying influences present within the provided measuring space 313 is less compared to the flow path.

[0270] Consequently, a stabilized measuring environment is provided within said measuring spaces 313, so as to reduce measurement errors of the sensor unit 311.

[0271] Fig. 5A shows a fifth example of the centrifugal pump 1 according to the invention, isometrically cut, in a perspective view.

[0272] Fig. 5B shows an enlarged cutout from the isometric cut shown in Fig. 5A in an area of a first measuring unit 31. Fig. 5C shows a part of another isometric cut of the centrifugal pump 1 shown in Fig. 5A in the area of a first measuring unit 31. A cross sectional plane of the cross-section in Fig. 5C is thereby rotated relatively to a cross-sectional plane of the cross-section shown in Fig. 5B.

[0273] Fig. 5D shows an inlet pipe 14a of the centrifugal pump 1 shown in Fig. 5A, isometrically cut, in a perspective view.

[0274] Fig. 5E shows a base part 121 of the centrifugal pump 1 shown in Fig. 5A, isometrically cut, in a perspective view.

[0275] Fig. 5A to 5E will be described together in the following.

[0276] The setup of the centrifugal pump 1 according to the fifth example corresponds largely to the setup of the centrifugal pump 1 according to the fourth example shown in Fig. 4A to 4D. For this reason, identically or similarly designed sections / components of the centrifugal pump according to the fifth example not be repeated here.

[0277] The centrifugal pump 1 according to the fifth example mainly distinguishes from the fourth example by the setup of the first measuring section 312 of the first measuring unit 31, which is described in the following.

[0278] Preferably, the first communication section 314 of the first measuring section 312 is formed as a gap section within the pump body 10, with the gap section being circumferentially arranged around the flow path, so as to partially or completely surround the flow path with respect to a circumferential direction, wherein the first communication section 314 particularly comprises a first subsection 314-1 and one or more second subsections 314-2, connected in series to the first subsection 314-1. The respective subsections 314-1, 314-2 may be connected by an angled or bent section; i.e. extending in a defined angled orientation with respect to each other, e.g., orthogonally to each other.

[0279] Preferably, the first subsection 314-1 is directly adjacent to the flow path and is more preferably defined by a first contour surface 312-11 of the end section 312-1 of the inlet pipe 14a and a first contour surface 312-21 of the end section 312-2 of the inlet 11. In that manner, the first subsection 314-1 is formed between said end-section 312-1, 312-2.

[0280] However, the first subsection 314-1 can also be designed as being completely formed within one of said end-sections 312-1, 312-2. Preferably, the first subsection 314-1 extends outwards from the flow path along a radial direction, wherein the first subsection 314-1 might partially or completely surround the flow path with respect to the circumferential direction.

[0281] In case of the fifth example shown in Fig. 5A to 5D, the first subsection 314-1 completely surrounds the flow path and particularly has an annular shape.

[0282] Preferably, the first contour surface 312-11 of the end section 312-1 of the inlet pipe 14a and / or the first contour surface 312-21 of the end section 312-2 of the inlet 11 extend in a radial and circumferential direction, as exemplary shown in Fig. 5A to 5E, wherein said directions are part of a cylindrical coordinate system, in which the transport direction of the fluid preferably corresponds to an axial direction of the cylindrical coordinate system.

[0283] In order to connect the first subsection 314-1 with the first measuring space 313, the first communication section 314 comprises said one or more second subsections 314-2, connected in series to the first subsection 314-1, thus, in between the first subsection 314-1 and the first measuring space 313.

[0284] In case of the fifth example shown in Fig. 5A to 5D, the first communication section 314 comprises just one second subsection 314-2, which preferably extends from a downstream portion of the first subsection 314-1 along the axial direction towards the first measuring space 313 (cf. Fig. 5C).

[0285] Preferably, the one second subsection 314-2 extends only partially over the circumference, thus, not completely surrounding the flow path. In that manner, the one second subsection 314-2 preferably has the geometric shape of a section of a ring or of a generalized hollowed cylinder.

[0286] In other words, if the one second subsection 314-2 extends only partially over the circumference, there are circumferential points at which the one second subsection 314-2 is present and other circumferential points at which the one second subsection 314-2 is not present.

[0287] Exemplary, Fig. 5B shows a cross-section of a region of the end-sections 312-1, 312-2, in which the second subsection 314-2 is not present, whereases in the cross-section shown in Fig. 5C shows a region, in which the second subsection 314-2 is present.

[0288] In that manner, it is preferable that the one second subsection 314-2 is arranged so as to not coincide with a position of a connecting port (like the hydraulic connection channel 315? 325, respectively), via which the first measuring space 313 of connected to the respective sensor unit 311, with respect to the circumferential direction. Such a case is exemplary shown in Fig. 5B, in which the connecting port is shown as connection to the first hydraulic channel 315, wherein the one second subsection 314-2 is not present at this circumferential point, especially compared to the case shown in Fig. 5B.

[0289] Preferably, the one second subsection 314-2 is defined by a respective second contour surface 312-12 of the end section 312-1 of the inlet pipe 14a and a respective second contour surface 312-22 of the end section 312-2 of the inlet 11 of the pump body 10.

[0290] In particular, said second contour surfaces 312-12, 312-22 have the shape of a sectioned cylindrical surfaces, in between which the fluid is capable of flowing from the downstream portion of the first subsection 314-1 to the first measuring space 313.

[0291] Preferably, a circumferential width of second subsections 314-2 is in a range from iso) 5t0 ' 360, withrbeing a radial distance of the one or more second subsections 314-2 to a center line of the flow path, with respect to the radial direction.

[0292] In the depicted case of the fifth example, the one second subsection 314-2 preferably extends in a range from ’ 320, more preferably within a range from (n— ) ■ 240 to ( n — ) ■ 320, so as to surround a maiority of the circumference. k 180 / k 180 / ’J J

[0293] The foregoing realization of a gap section as first communication section 314 of the first measuring section 312 is not limited to the first measuring unit 31, but can also be applied to other measuring units of the centrifugal pump 1, such as a measuring unit located at the outlet 13 or at the volute section 122.

[0294] With the given setup, in which the second partial communication section 314-2 does not extend along the whole circumference of the respective end-sections 312-1, 312-2, the flow of the fluid into the first measuring space 313 can be further calmed down.

[0295] By means of the described measuring unit 31, the pressure of the fluid is not measured directly within the flow path itself, but within the spatially separated, flow-calmed measuring spaces 313, such that the amount of measurement falsifying influences present within the provided measuring space 313 is less compared to the flow path.

[0296] Consequently, a stabilized measuring environment is provided within said measuring spaces 313, so as to reduce measurement errors of the sensor unit 311.

[0297] Fig. 6A shows a sixth example of the centrifugal pump 1 according to the invention, isometrically cut, in a perspective view. Fig. 6B shows an enlarged cutout from the isometric cut shown in Fig. 6A in an area of a first measuring unit 31.

[0298] Fig. 6C shows a part of another isometric cut of the centrifugal pump 1 shown in Fig. 6A in the area of a first measuring unit 31. A cross sectional plane of the cross-section in Fig. 6C is thereby rotated relatively to a cross-sectional plane of the cross-section in Fig. 6B.

[0299] Fig. 6D shows an inlet pipe 14a of the centrifugal pump 1 shown in Fig. 6A, isometrically cut, in a perspective view.

[0300] Fig. 6E shows a base part 121 of the centrifugal pump 1 shown in Fig. 6A, isometrically cut, in a perspective view.

[0301] Fig. 6A to 6E will be described together in the following.

[0302] The setup of the centrifugal pump 1 according to the sixth example corresponds largely to the setup of the centrifugal pump 1 according to the fourth example shown in Fig. 4A to 4D. For this reason, identically or similarly designed sections / components of the centrifugal pump according to the fifth example not be repeated here.

[0303] The centrifugal pump 1 according to the fifth example mainly distinguishes from the fourth example by the setup of the first measuring section 312 of the first measuring unit 31, which is described in the following.

[0304] Preferably, the first communication section 314 of the first measuring section 312 is formed as a gap section within the pump body 10, with the gap section being circumferentially arranged around the flow path, so as to partially or completely surround the flow path with respect to a circumferential direction, wherein the first communication section 314 particularly comprises a first subsection 314-1 and one or more second subsections 314-2, connected in series to the first subsection 314-1. The respective subsections 314-1, 314-2 may be connected by an angled or bent section; i.e. extending in a defined angled orientation with respect to each other, e.g., orthogonally to each other.

[0305] Preferably, the first subsection 314-1 is directly adjacent to the flow path and is more preferably defined by a first contour surface 312-11 of the end section 312-1 of the inlet pipe 14a and a first contour surface 312-21 of the end section 312-2 of the inlet 11. In that manner, the first subsection 314-1 is formed between said end-section 312-1, 312-2.

[0306] However, the first subsection 314-1 can also be designed as being completely formed within one of said end-sections 312-1, 312-2. Preferably, the first subsection 314-1 extends outwards from the flow path along a radial direction, wherein the first subsection 314-1 might partially or completely surround the flow path with respect to the circumferential direction.

[0307] In case of the sixth example shown in Fig. 6A to 6E, the first subsection 314-1 completely surrounds the flow path and particularly has an annular shape.

[0308] Preferably, the first contour surface 312-11 of the end section 312-1 of the inlet pipe 14a and / or the first contour surface 312-21 of the end section 312-2 of the inlet 11 extend in a radial and circumferential direction, as exemplary shown in Fig. 5A to 5E, wherein said directions are part of a cylindrical coordinate system, in which the transport direction of the fluid preferably corresponds to an axial direction of the cylindrical coordinate system.

[0309] In order to connect the first subsection 314-1 with the first measuring space 313, the first communication section 314 comprises said one or more second subsections 314-2, connected in series to the first subsection 314-1, thus, in between the first subsection 314-1 and the first measuring space 313.

[0310] In case of the sixth example shown in Fig. 6A to 6E, the first communication section 314 comprises multiple second subsections 314-2, which preferably extend from a downstream portion of the first subsection 314-1 along the axial direction towards the first measuring space 313 (cf. Fig. 6C).

[0311] In that manner, the multiple second subsections 314-2 could be seen as parallel connected to each other, wherein the total of the multiple second subsections 314-2 is preferably connected in series to the first subsection 314-1.

[0312] Preferably, the multiple second subsection 314-2 are located at defined positions along the circumferential direction, spaced apart from each other,

[0313] Each second subsection 314-2 of those multiple second subsections 314-2 thereby extends only partially over the circumference, thus, not completely surrounding the flow path. In that manner, the each second subsection 314-2 preferably has the geometric shape of a section of a ring or of a generalized hollowed cylinder.

[0314] In other words, if the multiple second subsections 314-2 extends only partially over the circumference, there are circumferential points at which the a second subsection 314-2 is present and other circumferential points at which no second subsection 314-2 is present. Exemplary, Fig. 6B shows a cross-section of a region of the end-sections 312-1, 312-2, in which a second subsection 314-2 is not present, whereases in the cross-section shown in Fig. 6C shows a region, in which a second subsection 314-2 is present.

[0315] In that manner, it is preferable that the multiple second subsections 314-2 are arranged so as to not coincide with a position of a connecting port (like the hydraulic connection channel 315, 325), via which the first measuring space 313 is connected to the respective sensor unit 311, with respect to the circumferential direction. Such a case is exemplary shown in Fig. 6B, in which the connecting port is shown as connection to the first hydraulic channel 315, wherein there is no second subsection 314-2 present at this circumferential point, especially compared to the case shown in Fig. 6B.

[0316] Preferably, the multiple second subsection 314-2 are defined by respective second contour surfaces 312-12 of the end section 312-1 of the inlet pipe 14a and respective second contour surfaces 312-22 of the end section 312-2 of the inlet 11 of the pump body 10.

[0317] Preferably, the respective second contour surfaces 312-12 of the end section 312-1 of the inlet pipe 14a are provided as inlet pipe grooves 312-12* distributed over a circumference of the end section 312-1 of the inlet pipe 14a.

[0318] Preferably, a circumferential width of each of the second subsections 314-2 is in a range from ’ 360, with r being a radial distance of the one or more second subsections 314-2 to a center line of the flow path, with respect to the radial direction.

[0319] In the depicted case of the sixth example, the channels thereby preferably each extend in a range from ’ 50, more preferably within a range from ’ 10 to (n— ■ 25. k 180 /

[0320] The foregoing realization of a gap section as first communication section 314 of the first measuring section 312 is not limited to the first measuring unit 31, but can also be applied to other measuring units of the centrifugal pump 1, such as a measuring unit located at the outlet 13 or at the volute section 122.

[0321] With the given setup, in which the second partial communication section 314-2 does not extend along the whole circumference of the respective end-sections 312-1, 312-2, the flow of the fluid into the first measuring space 313 can be further calmed down.

[0322] By means of the described measuring unit 31, the pressure of the fluid is not measured directly within the flow path itself, but within the spatially separated, flow-calmed measuring spaces 313, such that the amount of measurement falsifying influences present within the provided measuring space 313 is less compared to the flow path.

[0323] Consequently, a stabilized measuring environment is provided within said measuring spaces 313, so as to reduce measurement errors of the sensor unit 311.

[0324] Fig. 7A shows a seventh example of the centrifugal pump 1 according to the invention, isometrically cut, in a perspective view.

[0325] Fig. 7B shows an enlarged cutout from the isometric cut shown in Fig. 7A in an area of a first measuring unit 31.

[0326] Fig. 7C shows a part of another isometric cut of the centrifugal pump 1 shown in Fig. 7A in the area of a first measuring unit 31. A cross sectional plane of the cross-section in Fig. 7C is thereby rotated relatively to a cross-sectional plane of the cross-section in Fig. 7B.

[0327] Fig. 7D shows an inlet pipe 14a of the centrifugal pump 1 shown in Fig. 7A, isometrically cut, in a perspective view.

[0328] Fig. 7E shows a base part 121 of the centrifugal pump 1 shown in Fig. 7A, isometrically cut, in a perspective view.

[0329] Fig. 7A to 7E will be described together in the following.

[0330] The setup of the centrifugal pump 1 according to the seventh example corresponds largely to the setup of the centrifugal pump 1 according to the sixth example shown in Fig. 6A to 6E. For this reason, identically or similarly designed sections / components of the centrifugal pump according to the fifth example not be repeated here.

[0331] The centrifugal pump 1 according to the seventh example mainly distinguishes from the sixth example by the realization of the second contour surfaces 312-12, 312-22 defining the multiple second subsections 314-2.

[0332] Contrary to the sixth example, the respective second contour surfaces 312-22 of the end section 312-2 of the inlet 11 are provided as inlet grooves 312-22* distributed over a circumference of the end section 312-2 of the inlet 11.

[0333] The foregoing realization of a gap section as first communication section 314 of the first measuring section 312 is not limited to the first measuring unit 31, but can also be applied to other measuring units of the centrifugal pump 1, such as a measuring unit located at the outlet 13 or at the volute section 122. It shall be emphasized, that the present invention is in no way limited to the aforementioned examples and their features. The invention further encompasses modifications of those examples, in particular those resulting from modifications and / or combinations of individual or multiple features of the described examples within the scope of protection of the independent claims.

[0334] List of reference numbers

[0335] 1 centrifugal pump to pump body n inlet

[0336] 12 impeller housing

[0337] 13 outlet

[0338] 14a, 14b inlet pipe

[0339] 15 sealing member

[0340] 20 impeller

[0341] 21 impeller shaft

[0342] 22 shaft support

[0343] 31 first measuring unit

[0344] 32 second measuring unit

[0345] 33 third measuring unit

[0346] 121 base part

[0347] 122 volute section

[0348] 123 cover section

[0349] 124 sensor port

[0350] 311 first sensor unit

[0351] 312 first measuring section

[0352] 312-1 end section of inlet pipe

[0353] 312-2 end section of inlet

[0354] 312-11 first contour surface of end section of inletpipe

[0355] 312-12 second contour surface of end section ofinletpipe

[0356] 312-12* inlet pipe groove

[0357] 312-21 first contour surface of end section of inlet

[0358] 312-22 second contour surface of end section ofinletpipe

[0359] 312-22* inlet groove

[0360] 313 first measuring space

[0361] 314 first communication section

[0362] 314-1 first sub-section

[0363] 314-2 second sub-section first hydraulic connection channel second sensor unit second measuring section -1 receiving section -2 inlay element second measuring space second communication section second hydraulic connection channel third measuring section -1 end section of cover section -2 end section of volute section third measuring space third communication section

Claims

1. CLAIMS1. A centrifugal pump (1) for pumping a fluid, comprising:- a pump body (io) having an impeller housing (12), an inlet (11) and an outlet (13), which together define a flow path for the fluid;- an impeller (20), which is rotatably supported within the impeller housing (12), for transporting the fluid from the inlet (11) along the flow path to the outlet (13); and- a fluid measuring device for measuring a pressure of the fluid, wherein the fluid measuring device comprises one or a plurality of measuring units (31, 32, 33), each being arranged to measure the pressure of the fluid at a respective upstream or downstream position of the flow path relative to the impeller (20); wherein each of the one or the plurality of measuring units (31, 32, 33) comprises a sensor unit (311, 321) and a related measuring section (312, 322, 332) enclosing a respective measuring space (313, 323, 333), wherein each measuring space (313, 323, 333) is spatially separated from the flow path and arranged to hydraulically communicate through a communication section (314, 324, 334) of the respective measuring section (312, 322, 332), with an upstream position or a downstream position of the flow path relative to the impeller (20), such that the measuring space (313, 323, 333) is filled with fluid from the flow path when the fluid is transported by the impeller (20) along the flow path, and each sensor unit (311, 321) is arranged to measure the pressure of the fluid inside the measuring space (313, 323, 333) of the related measuring section (312, 322, 332).

2. Centrifugal pump (1) according to claim 1, wherein the fluid measuring device comprises at least two measuring units (31, 32, 33), wherein a first measuring unit (31) of the at least two measuring units (31, 32, 33) is arranged to measure the pressure of the fluid at an upstream position of the flow path relative to the impeller (20), and a second measuring unit (32) of the at least two measuring units (31, 32, 33) is arranged to measure the pressure of the fluid at a downstream position of the flow path relative to the impeller (20).

3. Centrifugal pump (1) according to claim 2, wherein the fluid measuring device is configured to determine a differential pressure value of the of the fluid based at least on the measurement values from both, the sensor unit (311) of the first measuring unit (31) and the sensor unit (321) of the second measuring unit (32).4- Centrifugal pump (1) according to claim 2 or 3, wherein the sensor unit (311) of the first measuring unit (31) and the sensor unit (321) of the second measuring unit (32) are designed as separate components.

5. Centrifugal pump (1) according to claim 2 or 3, wherein the sensor unit (311) of the first measuring unit (31) and the sensor unit (321) of the second measuring unit (32) are designed together in the form of a differential pressure sensor, wherein the differential pressure sensor is configured to measure the differential value.

6. Centrifugal pump (1) according to one of claims 2 to 5, wherein a first hydraulic connection channel (315) of the first measuring unit (31), connecting its sensor unit (311) with the measuring space (313) of its measuring section (312), and a second hydraulic connection channel (325) of the second measuring unit (32), connecting its sensor unit (321) with the measuring space (323) of its measuring section (322), are formed by a single measuring channel connecting the measuring space (313) of the first measuring unit (31) and the measuring space (323) of the second measuring unit (32), wherein the measuring channel preferably extends straight through the pump body (10).

7. Centrifugal pump (1) according to any one of claims 1 to 6, wherein for one or more of the one or the plurality of measuring units (31, 32, 33), a hydraulic connection channel (315, 325) connecting the respective sensor unit (311, 321) with the measuring space (313, 323) of its related measuring section (312, 322) is at least partially formed as a vacancy within the pump body (10).

8. Centrifugal pump (1) according to any one of claims 1 to 7, wherein for one or more of the one or the plurality of measuring units (31, 32, 33), the communication section (314, 324, 334) of the respective measuring section (312, 322, 332) comprises at least one or a plurality of communications channels, wherein each communication channel is preferably formed as a through-hole, more preferably in the form of a skewed or straight generalized cylindrical hole with a circular or longitudinal cross - section, wherein the plurality of channels are preferably evenly distributed along the respective measuring section (312, 322, 332).

9. Centrifugal pump (1) according to claim 8, wherein for at least one of the one or more of the one or the plurality of measuring units (31, 32, 33), whose communication sections (314, 324, 334) comprises at least one or a plurality of communications channels, the one or plurality of communication channels extend in adirection radial to a transporting direction of the fluid when being transported along the flow path, wherein a connection port at the respective measuring space for connecting the respective measuring space (313, 323, 333) with the related sensor unit (311, 321) is preferably arranged non-coaxially to the at least one or to any one of the plurality of communication channels.

10. Centrifugal pump (1) according to any one of claims 1 to 9, wherein the measuring space (313, 323, 333) enclosed by the respective measuring section (312, 322, 332) of one or more of the one or the plurality of measuring units (31, 32, 33) is ringshaped or has the geometric shape of a hollowed generalized cylinder, which is circumferentially arranged around the flow path.

11. Centrifugal pump (1) according to one of claims 1 to 10, wherein for one or more of the one or the plurality of measuring units (31, 32, 33), the communication section (314, 324, 334) of the respective measuring section (312, 322, 332) is formed as a gap section within the pump body (10), with the gap section being circumferentially arranged around the flow path, so as to partially or completely surround the flow path with respect to a circumferential direction.

12. Centrifugal pump (1) according to claim 11, wherein for one or more of the measuring sections (312, 322, 332) their respective gap section comprises a first subsection (314-1) and one or more second subsections (314-2), connected in series to the first subsection (314-1), wherein the respective subsections (314-1, 314-2) are preferably connected by an angled or bent section.

13. Centrifugal pump (1) according to claim 12, wherein for one or more of the measuring sections (312, 322, 332) the first subsection (314-1) of their respective gap section is directly adjacent to the flow path and extends outwards from the flow path along a radial direction, and in particular the first subsection (314-1) partially or completely surrounds the flow path with respect to the circumferential direction.

14. Centrifugal pump (1) according to one of claims 12 or 13, wherein for one or more of the measuring sections (312, 322, 332) the one or more second subsections (314-2) of their respective gap section extend from a downstream portion of thefirst subsection (314-1) along an axial direction towards the measuring space (313, 322, 332) of the respective measuring section (312, 322, 332).

15. Centrifugal pump (1) according to one of claims 12 to 14, wherein for one or more of the measuring sections (312, 322, 332) the one or more second subsections (314-2) of their respective gap section are arranged at defined positions along the circumferential direction, spaced apart from each other, wherein a circumferential width of the one or more second subsections (314-2) is preferably in a range from ’ 360, with r being a radial distance of the oneor more second subsections (314-2) to a center line of the flow path, with respect to the radial direction.

16. Centrifugal pump (1) according to claim 15, wherein for one or more of the measuring sections (312, 322, 332) the one or more second subsections (314-2) are arranged so as to not coincide with a position of a connecting port, like the hydraulic connection channel (315, 325) if present, via which the measuring space (313? 322, 332) of the respective measuring section (312, 322, 332) is connected to the respective sensor unit (311, 321), with respect to the circumferential direction.

17. Centrifugal pump (1) according to one of claims 1 to 16, wherein for one or more of the one or the plurality of measuring units (31, 32, 33), an inlay element (322-2) and a respectively adapted receiving section (322-1) of the inlet (11) or of the outlet (13) together form the respective measuring section (322), wherein the receiving section (322-1) is preferably designed as a recess of an inner contour of the inlet (11) or of the outlet (13), respectively, and the inlay element (322-2) is preferably designed as a ring element fitting into the receiving section (322-1).

18. Centrifugal pump (1) according to one of claims 1 to 17, wherein the centrifugal pump (1) further comprises an inlet pipe (14a, 14b), which is mechanically connected to the inlet (11), preferably by means of a flange connection or by means of a fit connection, in particular by means of an interference fit connection, wherein preferably an end section (312-1) of the inlet pipe (14a, 14b) and an end section (312-2) of the inlet (11) together form a measuring section (312) of one of the one or the plurality of measuring units (31, 32, 33), such that the respective measuring section (312) is provided at an interface between the inlet pipe (14a, 14b) and the inlet (11) of the pump body (10).19- Centrifugal pump (1) according to one of claims 1 to 18, wherein the centrifugal pump (1) further comprises an outlet pipe, which is mechanically connected to the outlet (13), preferably by means of a flange connection or by means of a fit connection, in particular by means of an interference fit connection, wherein preferably an end section of the outlet pipe and an end section of the outlet (13) together form a respective measuring section of one of the one or the plurality of measuring units (31, 32, 33), such that the respective measuring section is provided at an interface between the outlet pipe and the outlet (13) of the pump body (10).

20. Centrifugal pump (1) according to one of claims 1 to 19, wherein the impeller housing (12) comprises a volute section (122), which is located between the impeller (20) and the outlet (13) with respect to the flow path, wherein a respective measuring section (332) of one of the one or the plurality of measuring units (31, 32, 33) is arranged at the volute section (122), wherein the impeller housing (12) preferably further comprises a cover section (123) mechanically connected to the volute section (122), such that the cover section (123) and the volute section (122) together enclose the impeller (20), wherein an end section (332-1) of the cover section (123) and an end section (332-2) of the volute section (122) together preferably form the respective measuring section (332) of the one of the one or the plurality of measuring units (31, 32, 33) arranged at the volute section (122), such that the respective measuring section (332) is provided at an interface between the cover section (123) and the volute section (122).

21. A pump system, in particular a booster system, comprising K hydraulically connected centrifugal pumps, with integer K>2, from which L centrifugal pumps are centrifugal pumps (1) according to one of claims 1 to 20, with integer L>2 and L<K, wherein the K centrifugal pumps are preferably designed as in-line centrifugal pumps whose flow paths are arranged in-line to form a connected system flow path.

Images