EP2933365B1 - Method for regulating a recirculation pump system - Google Patents

Description

The invention relates to a method for controlling a Umwutungspumpen system with a Umflutungspumpe with measurable operating characteristics for the circulation of wash liquor with adjustable volume flow in a tub of a washing machine. Furthermore, the invention relates to a washing machine with a control device for a Umwutungspumpen system, wherein the control device is set up and designed such that it performs the inventive use of the washing machine, a method according to the invention for controlling the Umwutungspumpen system.

As Schlurfpumpen in connection with circulation pump systems of washing machines referred to the conveying of a wash liquor-air mixture, which is associated with acoustic impairments. So that this state does not occur during the operation of the bypass pump system, a clocked volume flow operation is performed. Volume flows in the context of the present invention have the dimension volume unit per unit time. In said clocked volume flow operation, the Umflutungspumpe is turned on for a defined period of time and turned off again, before the liquor level in the tub has dropped so far that air could be sucked. By switching off the pump, the lye collects again, so that the pressure rises again and the pump can be switched on again.

A preferred mode of operation of circulating pump systems with adjustable volume flow, for example, when using a variable speed Umflutungspumpe, is to operate the Umflutungspumpe alternately with two different flow rates. These are each set for defined periods. This mode of operation serves the purpose of using the spray jet of a Umwutungsdüse to reach all areas of the laundry both in the rear drum area (= high volume flow) and in the front drum area near the door glass (= low volume flow). As a result, a uniform moisture penetration and flow is achieved and as a result improves the washing effect.

The total quantity of introduced wash liquor is divided during the washing process into the bound liquor fixed in the damp laundry and the free liquor circulated in the liquor tank by the circulating pump. The fill level of the free liquor must not fall below a certain minimum level if the purpose of avoiding the needling is to be avoided. Depending on the specific properties of the laundry (absorbency, Durchströmfähigkeit) and the parameters of the washing process, the level of the free liquor in the intake of Umflutungspumpe will vary. In this respect, the maximum time interval of a high volume flow, before the Schlumpfpumpen the Umflutungspumpe sets depending on external conditions that can be very different. An on average high flow rate of the free liquor is desirable because it improves the washing result. However, this entails the increased risk of unwanted snorting.

The EP 1 887 443 A1 describes a method for controlling a flooding pump system, in which, however, only with environmental sensors, for example, a sound analysis is performed.

The invention thus presents the problem to provide a method for controlling a Umwutppumpen-system, which allows for circulating the free fleet on averaged high volume flow and at the same time minimizes the occurrence of Schlumping.

According to the invention, this problem is solved by a method for controlling with the features of patent claim 1. Advantageous embodiments and further developments of the invention will become apparent from the following subclaims.

1. a) Betreiben des Umflutungspumpen-Systems mit Betriebsparametern wie mindestens einem Volumenstrom während eines Volumenstrom-Zeitintervalls,
2. b) Analyse der Laufeigenschaften des Umflutungspumpen-Systems während des Betreibens des Umflutungspumpen-Systems gemäß Verfahrensschritt a) zum Detektieren eines Schlürfpumpens eines Waschlaugen-Luft-Gemisches durch die Umflutungspumpe,
3. c) Speichern von Schlürfpump-Informationen, wenn in Schritt b) das Schlürfpumpen der Umflutungspumpe detektiert worden ist,
4. d) Vergleich der in Schritt c) gewonnenen Schlürfpump-Informationen mit mindestens einem vorgegebenen und zugeordneten Schlürfpump-Richtwert,
5. e) Verändern mindestens einer der Betriebsparameter bestehend aus dem Volumenstrom und dem Volumenstrom-Zeitintervall, derart, dass ein vom Umwälzpumpen-System umgewälzter zeitlich gemittelter Volumenstrom reduziert wird, wenn der mindestens eine Schlürfpump-Richtwert im Verfahrensschritt d) überschritten worden ist, und
6. f) Abwarten einer Wartezeit und/oder Wiederholen der Verfahrensschritte b) bis e), so lange bis während des Betreibens des Umflutungspumpen-Systems das Schlürfpumpen der Umflutungspumpe über die messbaren Laufeigenschaften nicht mehr detektiert wird.

The method comprises the following method steps:

1. a) operating the bypass pump system with operating parameters such as at least one volume flow during a volume flow time interval,
2. b) analyzing the flow characteristics of the flooding pump system during operation of the flooding pump system according to method step a) for detecting a Schlump pumping of a wash liquor-air mixture by the flooding pump,
3. c) storing sipple pumping information when, in step b), whirling pump of the whirling pump has been detected,
4. d) comparison of the Schlumppump information obtained in step c) with at least one predefined and assigned Schlumppump reference value,
5. e) changing at least one of the operating parameters consisting of the volume flow and the volume flow time interval, such that a time-average volume flow circulated by the circulation pump system is reduced when the at least one Schlürfpump guide value has been exceeded in method step d), and
6. f) Waiting for a waiting time and / or repeating the process steps b) to e), until the operation of the bypass pump system until the Schlürfpumpen the circulating pump is no longer detected on the measurable running properties.

The achievable with the present invention consist in that a high volume flow of free liquor is circulated over time, at the same time running properties of the Umwutpumpsystems are monitored to detect a possibly occurring Schlürfpumpen and initiate countermeasures to prevent the Schlumpfpumpens depending on predetermined reference values , The acoustically disturbing noise of the sneak pump is thereby minimized or avoided.

The operation of the bypass pump system with the mentioned operating parameters such as the at least one volumetric flow during the volumetric flow time interval can be carried out over the course of the washing process in the simplest form with only two different volumetric flows, a first and a second volumetric flow. It is preferably switched periodically back and forth between the two flow rates. The further second volume flow is chosen such that a Schlürfpumpen for most laundry situations is safely avoided. That is, it flows per unit time more or at least the same amount of free fleet back into the intake of Umflutungspumpe is circulated as a free fleet by means of the second volume flow. However, the first volume flow is higher than the amount of free liquor flowing per unit time through the laundry back into the suction of Umflutungspumpe. In this respect, it is only a question of the amount of the first volume flow time interval, whether during this period a Schlurfpumpen starts or not. The time-averaged volume flow results in this situation from the average value of the volume flow over a period which includes both volume flow time intervals. If the two volume flows are interchanged periodically, the time-averaged volume flow over the summed period of the first volume flow time interval results with the further second volume flow time interval.

Apart from this fairly simple situation with only two different volume flows, washing processes with a much larger number of different volume flows and associated volume flow time intervals are conceivable. This is for example the case even if the volume flow is not varied in different stages but continuously. With a continuous variation of the volume flow, the volume flow time interval associated with a volume flow is infinitesimal. Here, too, the time-averaged volumetric flow for a periodic variation of the volumetric flows results via the average formation of the volumetric flows during a time period.

For the control, it is advantageous if the bypass pump system is operated in a periodic change of different volume flows.

According to the invention, the measurable operating characteristics of the bypass pump system selected from the group comprising: direct pump parameters such as time course and / or amount of electric motor current driving the Umwutungspumpe, time course and / or amount of a Umwutungspumpen speed and time course and / or magnitude a received by the Umflutungspumpe electrical power and / or indirect pump parameters such as time course and / or quality of a generated by the Umwutungspumpe sound level and time course and / or quality of a vibration generated by the Umflutungspumpe. Depending on the specific technical training and design of the submersible pump system, the use of direct or indirect pump parameters can offer more advantages.

In the case of selecting the direct pump parameters, it is advantageous to use a variable speed pump motor as the electric motor for the Umflutungspumpe. The flooding pump system must be able to circulate different volume flows of the free liquor. This requirement can also be met by the combination of a non-speed controlled Umflutungspumpe with hydraulically acting controllable throttles.

For the speed-controlled pump motor of the Umflutungspumpe is preferably a frequency converter controlled brushless permanent magnet motor used. With this motor, the direct pump parameters can be analyzed and controlled very simply electronically.

The control for terminating the Schlürfpumpens influenced preferably as operating parameters, the direct pump parameters such as time course and / or amount of the Umflutungspumpe driving electric motor current, time course and / or amount of Umwutungspumpen speed and time course and / or amount of electrical power absorbed by the Umflutungspumpe Power.

It is advantageous that in method step e) the time-averaged volume flow is reduced from a start level to a reduced level, wherein the time-averaged volume flow is subsequently increased from the reduced level by means of a plurality of increase steps with associated increase levels in the direction of the start level. By lowering the time-averaged volume flow to a reduced level, the detected Schlürfpumpen the circulating pump system for the washing process is permanently stopped. It may be possible that the reduced level is reached only by several successive steps, because according to process step f) the process steps b) to e) are repeated. If peristaltic pumping is permanently prevented, the reduced level of the time-averaged volume flow is gradually increased in the direction of the start level. This process in turn serves to increase the total time averaged flow in order to maximize it, but to keep it below the limit from which a Schlurfpumpen occurs.

Preferably, after each increase step during an analysis period, the operation of the bypass pump system is examined for dinghy pumps, with a subsequent increase step of the time-averaged volume flow being executed only when no dart pumping has been detected. In this way, the system slowly scans upward after lowering the time-averaged volume flow. After each step, during the analysis period in which the time-averaged volume flow is kept constant, it is analyzed whether or not the scoop-pumping occurs again. In a periodically operated variation of the volume flows, this analysis period preferably extends over more than one of these periods.

If, after a further increase step, the scavenge pumping is detected, the time-averaged volume flow is preferably reduced again to the increase level before the further increase step. For the increase level before the further increase step, it has already been determined during the preceding analysis period that no slip pumping occurs.

In the event of re-occurrence of the sneaking pump, the time-averaged volume flow is preferably lowered by one or more incremental steps that have already been carried out. If the reduction takes place by two or more incremental steps, it is advantageous to significantly extend the analysis period before the renewed increase in the volumetric flow in comparison to the previous course of increase. In this way, it is easier to determine the level of increase below the threshold for the occurrence of snore pumping. The aim of the preferred embodiments of the control method is to find and dynamically maintain this maximum level of increase in a self-learning process if it changes in the course of the washing process.

The influencing of the time-averaged volume flow is realized particularly simply by using the at least one volume flow and / or its volume flow time interval as control variables. In particular, with the speed-controlled Umwutpumps this results in an electronically easy to implement embodiment.

In a first variant of the method, the system reacts immediately after a Schlurfpumpen was detected. This is preferably realized in that the Schlürfpump reference value specified and assigned in method step d) is zero is predetermined. The comparison of the Schlürfpump information with the Schlürfpump reference value carried out in method step e) thus directly leads to a change in the time-averaged volumetric flow by influencing the operating parameters of the circulation-pump system.

In a second variant of the method, the system does not react immediately after detecting a Schlurfpumpens. This is preferably realized in that the Schlürfpump reference value specified and assigned in method step d) is greater than zero and is compared with the amount of an electronic counter, which increases when a Schlampen pumping of the inundation pump is detected.

Advantageous developments of the preceding second variant of the method are that the electronic counter is continuously increased during the continuation of a detected sniffing pump or that the electronic counter is increased by one counting step during the duration of a detected sniffing pump. Depending on the setting and operation of the counter can thus be achieved the effect that only after a defined threshold of Schlürfpump events or after a defined accumulated time duration of one or more Schlürfpump events with the change in operating parameters is responded.

Furthermore, the invention relates to a washing machine with a tub and a Umwutungspumpen system for circulating wash liquor in the tub with different flow rates and a control device for the Umwutpumpsystem, wherein the control device is set up and designed such that this is the intended use of the washing machine of the previously described method for controlling the Umwutpumpsystems performs.

Figur 1

den zeitlichen Verlauf eines initial mit zwei unterschiedlichen Volumenströmen V1 und V2 betriebenen Waschzyklus eines Umflutungspumpen-Systems und

Figur 2

den zu Figur 1 entsprechenden zeitlichen Verlauf des Füllstands der freien Flotte im Ansaugbereich der Umflutungspumpe des Umflutungspumpen-Systems.

Various embodiments of the invention will be described with reference to the purely schematic drawings and described in more detail below. It shows:

FIG. 1

the time course of an initially operated with two different volume flows V1 and V2 washing cycle of a Umwutpumpsystems and

FIG. 2

which to FIG. 1 corresponding time course of the level of the free liquor in the intake of Umflutungspumpe the Umwutpumpsystem.

FIG. 1 shows the time course of an initially operated with two different volume flows V1 and V2 washing cycle of a Umwutpumpsystems.

FIG. 2 shows that too FIG. 1 corresponding time course of the level of free liquor in the tub of a washing machine, which is equipped with the Umwutungspumpen system.

The problems to be solved by the invention are based on the time profiles of the volume flow of the bypass pump system in FIG. 1 and the Laugenfüllstandes in the tub of a washing machine with the Umwutpump-system in FIG. 2 explained. The curves shown in solid lines represent the course to be improved in the prior art.

A preferred mode of operation of Umflutungspumpen-systems with variable-time flow rates, for example by means of a variable speed Umflutungspumpe, is to operate the Umflutungspumpe alternately, in particular periodically alternating, with two different flow rates. These are each set for defined periods. This mode of operation serves the purpose of achieving with the spray of a wash liquor in the washing drum of a washing machine Umflutungsdüse all areas of the laundry both in the rear washing drum area (= high volume flow) and in the front washing drum area near the door glass (= low volume flow). As a result, a uniform moisture penetration and flow through the laundry is achieved and as a result improves the washing effect.

As in FIG. 1 shown, the low flow V2 can be set for a period T2. This is so dimensioned that in the tub an in FIG. 2 level shown h2 sets, which is so high that the suction of the Umflutungspumpe the Umwutpumpsystem is free of air bubbles, so that an operation free of unwanted noise by air suction (= Schlurfpumpen) is guaranteed. If the period T2 has elapsed, the volume flow is increased to the higher value V1 for a period T1. This is desirable, as already mentioned, since the increased volume flow, for example, improves the washing action and / or the distribution of base and detergent. If the time period T1 is too long, the fill level of the wash liquor initially drops below the level h3 which is in FIG. 2 is designated as Schlürfgrenze. From this level, air can enter the intake area of the infiltration pump of the infiltration pump system. This leads to the Schlofferpump operation associated with unwanted noise. The Schlemmpumpen continues until the set period T1 has elapsed. At the end of the period T1, the level has dropped to the level h4. Subsequently, the volume flow is lowered to the value V2 again. Only when the filling level h3 is exceeded again during the following subsequent period T2, the Schlürfpumpen is completed.

By means of a preferably designed as frequenzumrichtergesteuerter, brushless permanent magnet motor drive for the Umflutungspumpe the Umflutungspumpen system, it is particularly easy to detect the onset of Schlürfpumpbetriebes. This can e.g. based on direct Schlumppump parameters in the form of engine parameters, e.g. done the recorded motor current.

The mode of operation described below leads to recognition of the sneak pumping operation and the resulting automatic setting of a mode which completely avoids or minimizes the sneaking pumping of the flushing pump system. The starting point is initially the operating mode with fixed periods T1 and T2 and the associated volume flows V1 and V2. In this mode of operation, as described above, it will happen that during the period T1, the slur limit is exceeded and the Schlurfpumpen occurs. This is detected by the drive of the pump. The occurrence of the Schlürfpumpen event can be counted for example by means of a counter. If the Schlurfpumpen in one of the subsequent cycles T1 and T2 on again, the counter is again increased. A threshold may be defined from which to take action described in the following embodiments. However, it is also possible that this limit is set to zero, so that the measures described below are initiated immediately after a Schlumping event has been detected.

A first embodiment of the control method consists in that the increased volume flow V1 is lowered to a value V3 reduced by a factor x (eg 0.9). If the pump in the next cycle with the in FIG. 1 operated volume flow V3 operated, the level is reduced slower. If the reduction of the volume flow is sufficient, then the slur limit h3 is not undershot, before it is converted to the volume flow V2, at which the level rises again. This would ensure operation without snorkelling pumps. On the other hand, if the reduction to the volume flow V3 is insufficient, the Schlürfpump mode is detected and the counter is increased if the slur limit is undershot. If the limit value is exceeded again, the volume flow V3 is then reduced by a factor. This procedure ensures that the volume flow is gradually reduced until the circulation pump system can be operated without the use of scavenge pumps.

Furthermore, it is provided in a preferred variant of the control method that the lowered level of the higher volume flow is gradually raised again. After each lift, an analysis period is waited to determine if the level in the tub is sufficient and remains, so that a Schlurfpumpen is avoided. As the level of the originally reduced higher volume flow continues to rise sooner or later, a snorkel pump will occur again. Then again a reduction of the volume flow begins. However, this reduction can be made to one of the previously traversed levels at which no scythes were detected during the analysis period. In this way, the system autonomously learns to maximize its total volume flow averaged over the two alternating periods T1 and T2 without provoking a sniffer pumping operation.

In a second embodiment of the control method, it is conceivable that, instead of reducing the volume flow, a reduction of the operating parameter of the switch-on time T1 is undertaken. The procedure is analogous to the previously described variants of the first embodiment.

In a third embodiment, it is conceivable that the operating parameter of the switch-on time T2 is extended with a low volumetric flow V2, so that the level can rise to a higher level than h1.

Moreover, it is conceivable to make the control of the system via a change in a combination of the operating parameters described above.

Claims (13)

1. Method for controlling a recirculation pump system comprising a recirculation pump with measurable running properties for the circulation of suds at an adjustable volumetric flow rate in a suds container of a washing machine, wherein the measurable running properties of the recirculation pump system are selected from the group that comprises: direct pump parameters such as a time curve and/or an amount of an electric motor current that drives the recirculation pump, a time curve and/or an amount of a recirculation pump rotational speed, and a time curve and/or an amount of an electric power that is received by the recirculation pump, and wherein the method comprises the following method steps:

   a) operating the recirculation pump system with operating parameters such as at least one volumetric flow rate (V1) during at least one volumetric flow rate-time interval (T1),

   b) analysing the running properties of the recirculation pump system during the operation of the recirculation pump system according to method step a) in order to detect slurp-pumping of a suds-air mixture through the recirculation pump system,

   c) recording slurp pump information if the slurp-pumping of the recirculation pump has been detected in step b),

   d) comparing the slurp pump information obtained in step c) with at least one predetermined and associated slurp pump standard value,

   e) varying at least one of the operating parameters consisting of the volumetric flow rate (V1) and the volumetric flow rate-time interval (T1) such that a time-averaged volumetric flow rate circulated by the circulation pump system is reduced if the at least one slurp pump standard value in method step d) has been exceeded, and

   waiting for a wait time and/or repeating method steps b) to e) until the slurp-pumping of the recirculation pump is no longer detected by means of the measurable running properties during the operation of the recirculation pump system.
2. Method according to claim 1, characterised in that a pump motor with an adjustable rotational speed is used as an electric motor for the recirculation pump if the direct pump parameters are selected.
3. Method according to claim 2, characterised in that the pump motor with an adjustable rotational speed is designed as a brushless permanent-magnet motor controlled by means of a frequency converter.
4. Method according to any of claims 1 to 3, characterised in that direct pump parameters such as the time curve and/or the amount of an electric motor current that drives the recirculation pump, the time curve and/or the amount of a recirculation pump rotational speed, and the time curve and/or the amount of an electric power that is received by the recirculation pump are controlled in order to vary the operating parameters mentioned in method step e).
5. Method according to any of claims 1 to 4, characterised in that, in method step e), the time-averaged volumetric flow rate is reduced from a starting level to a reduced level, the time-averaged volumetric flow rate subsequently being increased from a reduced level by means of a plurality of progression steps having associated progression levels towards the starting level.
6. Method according to claim 5, characterised in that the operation of the recirculation pump system is examined for slurp-pumping after every progression step during an analysis period, a subsequent progression step of the time-averaged volumetric flow rate being carried out only if no slurp-pumping has been detected.
7. Method according to claim 6, characterised in that, if the slurp-pumping is detected after a further progression step, the time-averaged volumetric flow rate is reduced again to the progression level before the further progression step.
8. Method according to claim 7, characterised in that, if the slurp-pumping reoccurs, the time-averaged volumetric flow rate is reduced by one or more progression steps that have already been carried out.
9. Method according to any of claims 4 to 8, characterised in that the at least one volumetric flow rate (V1) and/or the volumetric flow rate-time interval (T1) thereof are used as controlled variables for the time-averaged volumetric flow rate.
10. Method according to any of the preceding claims, characterised in that the associated slurp pump standard value predetermined in method step d) is zero.
11. Method according to any of claims 1 to 9, characterised in that the associated slurp pump standard value predetermined in method step d) is greater than zero and is compared with the amount of an electronic counter which increases when slurp-pumping of the recirculation pump is detected.
12. Method according to claim 11, characterised in that the electronic counter continues to be increased during a detected slurp-pumping process or in that the electronic counter is increased by one counting step during a detected slurp-pumping process.
13. Washing machine comprising a suds container and a recirculation pump system for circulating suds in the suds container at different volumetric flow rates, and a control means for the recirculation pump system, wherein the control means is designed such that it carries out a method for controlling the recirculation pump system according to any of the preceding claims when the washing machine is used as intended.

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