Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
  • F04B49/20—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 by changing the driving speed
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B17/00—Pumps characterised by combination with, or adaptation to, specific driving engines or motors
  • F04B17/03—Pumps characterised by combination with, or adaptation to, specific driving engines or motors driven by electric motors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
  • F04B49/06—Control using electricity
  • F04B49/065—Control using electricity and making use of computers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C14/00—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
  • F04C14/08—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the rotational speed
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
  • F04D15/0066—Control, e.g. regulation, of pumps, pumping installations or systems by changing the speed, e.g. of the driving engine
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B2203/00—Motor parameters
  • F04B2203/02—Motor parameters of rotating electric motors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B2205/00—Fluid parameters
  • F04B2205/09—Flow through the pump
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B2207/00—External parameters
  • F04B2207/04—Settings
  • F04B2207/041—Settings of flow
  • F04B2207/0411—Settings of flow maximum
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B2207/00—External parameters
  • F04B2207/04—Settings
  • F04B2207/041—Settings of flow
  • F04B2207/0412—Settings of flow minimum
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
  • F24D19/00—Details
  • F24D19/10—Arrangement or mounting of control or safety devices
  • F24D19/1006—Arrangement or mounting of control or safety devices for water heating systems
  • F24D19/1009—Arrangement or mounting of control or safety devices for water heating systems for central heating
  • F24D19/1012—Arrangement or mounting of control or safety devices for water heating systems for central heating by regulating the speed of a pump

Definitions

• the present invention relates to a method for performance-optimized operation of an electric motor-driven pump in a hydraulic system at very low flow rates, wherein the nominal head of the pump in
• the invention further relates to an electric motor operated pump with a control and regulating electronics, which is adapted to carry out the inventive method. Finally, the invention relates to a
• inventive method when it is executed in a control electronics of the pump.
• Target delivery of the pump is kept constant over the volume flow. Furthermore, so-called ⁇ - ⁇ characteristic curves are known in which the regulation of the pump takes place in accordance with a linear dependence of the nominal delivery height on the volume flow. ⁇ - ⁇ characteristics adjust the hydraulic power of the pump depending on the volumetric flow demand of the hydraulic system.
• a disadvantage of such a characteristic control is that the nominal delivery head of the pump with closed valves in the system, i. is not adjusted to the actual hydraulic demand of the system at a flow rate equal to zero.
• the control characteristic is rather defined for volume flows greater than zero and can only be used there. If, in addition, the control characteristic in the H / Q diagram is considered, the geometric characteristic of the control characteristic for the H axis of the
• CONFIRMATION COPY Diagram an intersection point with this axis before, which has a flow rate equal to zero, a comparatively high target delivery height for the pump.
• the pump therefore delivers against the closed valves in the system, which unnecessarily consumes power.
• volumetric flows wherein the target delivery height is controlled as a function of the volume flow along a preset characteristic
• a reference value which is a maximum of one tenth of the maximum volume flow on the characteristic, preferably one twentieth of this maximum value, wherein the lowering takes place as long as the volume flow is below the volume flow reference value and a minimum head height has not yet reached is.
• the basic idea of the method according to the invention is to reduce the nominal delivery head of the pump at very low flow rates, i. to depart from the regulation on the originally specified control characteristic at these low flow rates and instead the
• Controlled delivery of the pump selectively controlled to reduce, with a subordinate characteristic control can continue to be active.
• the lowering of the nominal delivery head of the pump can be achieved by reducing one of the pumps directly
• Feed height setpoint done. This can be done for example by reducing the pump speed, respectively the electric drive power.
• the pump motor is directly preset by the pump control to a specific nominal delivery height.
• the lowering of the nominal delivery height of the pump can be achieved by reducing the characteristic curve
• Characteristic setpoint conveying height.
• the characteristic setpoint head specifies the position of the characteristic curve in the characteristic field of the pump. For example, the
• Maximum speed descriptive curve can be specified. This means that, according to the invention, the lowering of the setpoint delivery height of the pump can also be achieved by shifting the position of the predetermined characteristic curve below the volume flow reference value.
• the pump motor is in this case indirectly a certain nominal lift height of the
• Prescribed pump control wherein a delivery height setpoint for the pump comes directly from the subordinate characteristic control.
• the core aspect of the invention is to make a reduction in the pump power when the volume flow is equal to zero, since in this case actually no pump capacity of the pump is needed.
• the pump is completely switched off, the system is no longer observable and can no longer respond to a change in the volume flow requirement. Furthermore, it is due to
• volume flow reference value which is a maximum of one tenth of the maximum volume flow, which is on the
• Preset control characteristic is reached.
• a smaller volume flow reference value can also be used, for example a reference value which is one twentieth of the maximum volume flow defined by the characteristic curve.
• the reference value is between 10 l / h and 250 l / h. Because the typical Design mass flow of a radiator is between 30 to 501 / h, is ensured with a lower limit of the reference value of about 10l / h sufficient operation of a single heating circuit in small systems. In larger systems, a larger limit value for the reference value makes sense, since a simultaneous operation of several consumers leads to a higher minimum operation of approx. 250 l / h, ie a higher minimum volume flow, which ensures the minimum supply of the simultaneously operating consumers.
• the nominal delivery height of the pump is lowered. This takes place as long as the volume flow is below the reference value and a minimum head is not yet reached.
• the setpoint of a subordinate characteristic control can be lowered or the speed of the pump can be reduced directly. In the latter case, the pump is operated purely controlled.
• the minimum head height is determined by the pressure difference required on the valves in the hydraulic system for any flow to flow in the system at all. It should be noted that in the hydraulic system gravity brakes, in particular backflow preventer can be used, which require a certain opening pressure, so that the medium flows. Only when this opening pressure is exceeded, a gravity brake allows a corresponding volume flow. It is therefore advantageous to the hydraulic system
• the minimum head height value must be based on how high the head of the pump must be at least to reach the opening pressure of the valves in the hydraulic system.
• the minimum head height is between 60cm and 200cm, depending on the design of the plant, in particular the backflow preventer used.
• Resistor inherently no flow, so that in such an operation the pump can not be determined whether and when a control valve of the system opens. If the system is formed by a heating system, for example, would open by opening a valve, such as a thermostatic valve no
• volume flow reference value increases.
• the setpoint delivery height can then be increased again and the regulations along the characteristic curve can be changed, if the volume flow increases or increases above the volume flow reference value. Outside the Absenkrios the target delivery height of the pump is thus raised again, in particular continuously until the original
• the characteristic curve along which the pump is controlled may be a pure ⁇ -c characteristic curve, a pure ⁇ - ⁇ characteristic curve or such a ⁇ -c or Ap-v characteristic curve that is changed over time, for example as a function of the temperature. That is, the
• Characteristic curve can describe a linear, quadratic or constant relationship between the volume flow and the delivery head and / or can be variable in time.
• the lowering of the nominal conveying height can take place in continuous operation with a constant lowering speed.
• the raising of the target conveying height after lowering can take place in continuous operation with a constant lifting speed.
• Lifting speed for the delivery height setpoint to be selected differently. It is particularly advantageous to set the lowering speed smaller than the lifting speed. With an increased volume flow demand this can then be served as quickly as possible.
• the nominal delivery height is increasingly lowered. This is preferably not done by switching, but continuously, so that in the hydraulic system no non-linear effects, in particular a tearing off of the flow can occur.
• the lowering takes place at a constant lowering speed. This means that the longer the operating point of the system is in the lowering range of the characteristic field, the further the nominal delivery height is lowered.
• the operating point in the H / Q diagram moves downwards on the respective current grid parabola until after a certain time the minimum delivery height has been reached.
• the pump is controlled in a clocked manner after reaching the minimum height of the delivery height.
• it alternates between a first delivery altitude value and a second delivery altitude value which is below the first delivery altitude value.
• a delivery height value is set below the first delivery height value.
• the switching between the two delivery height values preferably takes place in a uniform cycle.
• the pump is operated for the first time on the first delivery height value as a setpoint. For the duration of a second
• the second delivery level value is set for the pump.
• the second delivery height value may preferably correspond to the delivery height zero. This means that the pump is switched off for the duration of the second period. In this case, on the basis of the first delivery level value, a temporary switch-off (to zero cycles) or a cyclical switch-on of the pump takes place, whereby a discontinuous but energetically optimized operation is achieved.
• the second delivery altitude value may be any elevation value between the minimum altitude and the zero value.
• a second delivery level value at a level above zero delivery point has the advantage of ensuring sufficient pressure in the entire pipeline network have to drive the volume flow. The system thus remains completely observable even below the minimum head. For when a clocking between the first and the second delivery height value above the delivery value zero can be prevented that the mass flow in parts of the system due to the very low pressures and possible non-linear effects, such as thermal rotation or closing the valve flaps in gravity brakes, breaks off.
• the second delivery altitude value As an alternative to a fixed second delivery altitude value, the second
• Delivery level value also be variable. According to the invention, therefore, the delivery height of the pump after reaching the minimum height of the delivery height can preferably be further reduced in the mean that the pump between the
• Delivery level value is clocked, the second delivery level value is gradually reduced.
• Volume flow information can be obtained. Switching the pump back to the minimum level of the pump, or switching the pump to this value, ensures that the system becomes observable again and an increased volumetric flow requirement can be ascertained. It is therefore advantageous, at least during the period in which the pump with the first
• Delivery level value is operated, to check whether the flow rate over the
• Volume flow reference value increases or has increased. If it is determined during the check of the volumetric flow that it rises above the volumetric flow reference value or has risen, the nominal delivery height is raised again and the regulation along the characteristic curve is transferred.
• a steady, i. stepless transition to the control characteristic in order to adapt the performance to the actual requirements of the plant.
• Pump level value switched in a uniform cycle the pump is operated or switched off for a period between 0 and 120 seconds with the second delivery level value.
• Figure 1 H / Q diagram with ⁇ - ⁇ characteristic and marked Absenk Scheme at
• Figure 3 Representation of the transition from a continuous to a
• FIG. 1 shows a H / Q diagram 1 for a hydraulic system, here a
• Heating system with an electric motor driven pump.
• Reference numeral 2 indicates the lying on a characteristic operating points at maximum
• the pump is controlled in normal operation on a ⁇ - ⁇ characteristic K, according to which the target head H in linear dependence on
• Volume flow demand Q of the system is set. At maximum speed of the pump, a maximum volume flow Q_max is reached on the characteristic curve K.
• the then applied setpoint conveying height H is marked H_soll and corresponds to the characteristic setpoint conveying height.
• Reference value Q_ref which is about 5% of the maximum volume flow Q_ref, for example, 150 l / h, so the target head H of the pump is compared to the characteristic K lowered.
• the operating point has then in the in Figure 1
• hatched lowering area 3 is moved into it.
• the lowering takes place as long as the volume flow Q is below the volume flow reference value Q_ref and a minimum head H_min has not yet been reached.
• the minimum head height value H_min is dimensioned so that in his concern just the opening pressure of existing in the heating system valves and Gravity brakes is overcome, ie with open thermostatic valves, a volume flow is possible.
• the minimum head H_min is typically about 70cm for pumps for a one- to two-family house and about 1 m for pumps for larger buildings.
• the operating point of the heating system moves by lowering the nominal delivery height H along a not shown piping parabola in the direction of smaller volume flows Q to the minimum delivery height value H_min is reached.
• the fact that in continuous operation no further than the minimum delivery head H_min is lowered has the advantage that the heating system remains observable, because always at least a minimum volume flow Q is possible with valves not completely closed.
• the lowering speed can be, for example, 10 rpm per minute.
• a pulsed activation of the heating-medium circulation pump is transferred according to the invention, i. to a discontinuous operation, wherein alternately between the minimum height of the conveyor height H_min and an underlying, second delivery level value is switched.
• any desired height H can be set between the minimum head H_min and the lower second head.
• the pump can also be switched off for the second period. In this case, the heating system remains observable both when switching between the minimum head height H_min and the underlying head height value as well as the temporary shutdown of the pump, if at least during the Period by the pump is operated with the minimum amount H_min, it is checked whether the flow rate Q is above the flow rate reference value Q_ref increases or increased.
• the setpoint conveying height H is continuously raised, wherein the regulation along the characteristic curve K is changed over.
• the lifting speed is greater than the lowering speed chosen to quickly adjust the pump power to the requested volume flow Q.
• FIG. 3 shows the time transition from a continuous to a
• Head of minimum height H_min reached at time t1 is in a
• Delivery altitude value and a second delivery altitude value are clocked, i. switched periodically.
• the switching times are chosen identical.
• the first delivery height value corresponds to the previously reached minimum delivery altitude value H_min.
• the second delivery level value is below this minimum delivery altitude value and is gradually reduced until a second minimum delivery altitude value H_min2 is reached.
• the second delivery altitude value is reduced at each new cycle, as long as the second minimum delivery altitude value has not been reached.
• a certain second delivery altitude value can also be maintained over several cycles.
• the embodiment according to FIG. 3 has the advantage that the hydraulic system always remains observable, regardless of whether non-return valves are present in the system.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Computer Hardware Design (AREA)
• Control Of Positive-Displacement Pumps (AREA)
• Control Of Non-Positive-Displacement Pumps (AREA)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

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• 2011
  • 2011-01-10 DE DE102011008165A patent/DE102011008165A1/de not_active Withdrawn
• 2012
  • 2012-01-02 RU RU2013137441/06A patent/RU2553630C2/ru active
  • 2012-01-02 WO PCT/EP2012/000001 patent/WO2012095274A2/de not_active Ceased
  • 2012-01-02 EP EP12706187.7A patent/EP2663774B1/de active Active
  • 2012-01-02 CN CN201280004962.3A patent/CN103299076B/zh active Active

Non-Patent Citations (1)

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