EP4012314A1 - Dispositif, ainsi que procédé de détection d'un dépôt sur une surface d'échangeur de chaleur - Google Patents

Dispositif, ainsi que procédé de détection d'un dépôt sur une surface d'échangeur de chaleur Download PDF

Info

Publication number
EP4012314A1
EP4012314A1 EP21213541.2A EP21213541A EP4012314A1 EP 4012314 A1 EP4012314 A1 EP 4012314A1 EP 21213541 A EP21213541 A EP 21213541A EP 4012314 A1 EP4012314 A1 EP 4012314A1
Authority
EP
European Patent Office
Prior art keywords
parameter
deposit
fan
heat exchanger
maximum
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP21213541.2A
Other languages
German (de)
English (en)
Inventor
Sebastian LAUKNER
Gunnar Schmitt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Glen Dimplex Deutschland GmbH
Original Assignee
Glen Dimplex Deutschland GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Glen Dimplex Deutschland GmbH filed Critical Glen Dimplex Deutschland GmbH
Publication of EP4012314A1 publication Critical patent/EP4012314A1/fr
Pending legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F17/00—Removing ice or water from heat-exchange apparatus
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
    • F24F11/32—Responding to malfunctions or emergencies
    • F24F11/38—Failure diagnosis
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
    • F24F11/41—Defrosting; Preventing freezing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B30/00—Heat pumps
    • F25B30/02—Heat pumps of the compression type
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
    • F25B47/02—Defrosting cycles
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
    • F25B47/02—Defrosting cycles
    • F25B47/022—Defrosting cycles hot gas defrosting
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D1/00—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators
    • F28D1/02—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid
    • F28D1/0233—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with air flow channels
    • F28D1/024—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with air flow channels with an air driving element
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F19/00—Preventing the formation of deposits or corrosion, e.g. by using filters or scrapers
    • F28F19/006—Preventing deposits of ice
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2140/00—Control inputs relating to system states
    • F24F2140/20—Heat-exchange fluid temperature
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/029—Control issues
    • F25B2313/0294—Control issues related to the outdoor fan, e.g. controlling speed
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/04—Refrigeration circuit bypassing means
    • F25B2400/0403—Refrigeration circuit bypassing means for the condenser
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/04—Refrigeration circuit bypassing means
    • F25B2400/0411—Refrigeration circuit bypassing means for the expansion valve or capillary tube
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D21/00—Defrosting; Preventing frosting; Removing condensed or defrost water
    • F25D21/02—Detecting the presence of frost or condensate
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
    • F28D2021/0019—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for
    • F28D2021/0068—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for refrigerant cycles
    • F28D2021/0071—Evaporators

Definitions

  • the invention relates to a device and a method for detecting a deposit on a heat exchanger surface over which air flows.
  • Air-flow heat exchangers in which ambient air (atmospheric air) is passed over heat exchanger surfaces, are used, for example, in ventilation systems for ventilating buildings and in particular in heat pumps, in which heat is obtained from the ambient air.
  • a heat exchanger is used as an air-refrigerant heat exchanger, which is connected as an evaporator in a refrigerant circuit.
  • Heat pumps that use air as a heat source and are designed to prepare heating water or hot water are referred to as air-to-water heat pumps.
  • the atmospheric air used consists of the gaseous substances oxygen, nitrogen, noble gases and water vapour. If water vapor is cooled to temperatures below 0 °C during cooling on the outer surface of the heat exchanger surface (heat transfer surface) of the evaporator, frost/ice deposits form.
  • the ice or frost that forms can occur in various crystal structures and must be removed from the surface of the evaporator by a time-dependent defrosting process, which usually consists of finned tube coils and is blown with atmospheric air by a fan. From time to time (depending on the thickness of the ice), this defrosting process interrupts the heat pump's normal operating status for a while.
  • Air-air (cross-flow) heat exchangers are typically used here.
  • defrosting methods namely, for example, defrosting by means of electric heating, defrosting with water, defrosting with warm brine or defrosting with reverse circulation.
  • Defrosting by means of hot gas is specifically provided, which is routed from a condenser in the refrigerant circuit directly to the evaporator.
  • an electrically driven axial fan is used for an air-loaded evaporator.
  • a defrosting process uses a sensor to detect icing of the evaporator and, if icing occurs, the defrosting process is initiated by reversing the refrigerant circuit. It is described that the evaporator is advantageously equipped with a fan. Using a differential pressure sensor, which measures the air pressure on the suction side in front of the evaporator and in the flow direction of the air behind the evaporator, icing is detected and defrosting is initiated when icing is determined by a predetermined pressure difference. Other sensors such as temperature sensors or ice detectors can also be used for this.
  • DE 101 31 379 B4 describes a method for controlling the defrosting of an air/air heat exchanger of a ventilation system.
  • This method makes use of the fact that two fans are arranged in such a ventilation system, with one fan supplying exhaust air to the heat exchanger and the other fan supplying supply air to the room to be ventilated.
  • heat exchanger heat is exchanged between the fresh air and the exhaust air.
  • the two volume flows of the two fans are compared with each other.
  • the physical relationship is also exploited, that there is a relationship between the performance specification (control voltage and/or operating voltage) and the fan speed as well as the conveyed air volume flow for different fan types. In the event of a speed deviation between the two fans above a threshold value, the fan for the supply air is switched off for the start of defrosting.
  • defrosting requires heat energy on the one hand and the formation of deposits, such as icing, on the other hand, leads to a deterioration in heat transfer, there is a need for defrosting strategies that are as targeted as possible, especially for heat pumps where high energy efficiency is desired.
  • the object of the invention is to enable a needs-based defrosting strategy.
  • the object is achieved according to the invention by a device and a method for detecting a critical deposit on a heat exchanger surface exposed to air.
  • the device has a heat exchanger, for example an air-liquid heat exchanger, air-refrigerant heat exchanger or an air-air heat exchanger, which has the heat exchanger surface.
  • a fan is provided, which is designed in particular as an axial fan. This generally has impeller blades or fan blades which rotate during operation and which generate and promote the air flow.
  • the heat exchanger is preferably a finned heat exchanger. In this case, tubes (tube coils) are typically fitted with fins.
  • a heat transfer medium, specifically a refrigerant is guided in the pipes.
  • air heat exchangers of a different design can also be provided, in which the heat transfer medium is guided in channels.
  • a control unit is also provided for the decision as to whether a critical deposit has formed on the heat exchanger surface during operation, for example icing or contamination. This monitors and evaluates one or more parameters of the technical variables of the fan as a criterion for reaching an unstable state of the fan. If a previously defined, critical value (e.g. stored in the control unit) is reached or if a characteristic course of the value of the parameter is determined, a critical deposit is assumed. In particular, a signal is then emitted which at least indicates the critical deposit or initiates a countermeasure, such as a defrosting process.
  • a countermeasure such as a defrosting process.
  • This parameter is preferably a parameter for an electrical power consumption, in particular, of the fan, that is to say of an electric drive motor of the fan.
  • This is, for example, a motor current for the electric drive motor as a measure of the electric power consumed.
  • the electrical power consumption can also be recorded and evaluated directly.
  • a vibration parameter is monitored and evaluated as a characteristic variable for a vibration.
  • the monitoring of the parameter with regard to reaching an unstable state of the fan is based on the consideration that the flow conditions on the fan change with increasing deposit formation.
  • deposit formation regularly leads to an increasing pressure loss, ie an increasing pressure difference between an inlet side and an outflow side of the heat exchanger. This is due to the fact that the formation of deposits reduces the flow cross section of the heat exchanger available on the inlet side.
  • the pressure difference increases and the fan has to work harder as the deposits build up.
  • the power consumption of the fan increases accordingly.
  • Increasing deposit formation is therefore accompanied by increasing power consumption and increasing pressure (delivery pressure).
  • an increasing conveying pressure in particular in combination with low volume flows, means that an unstable operating range, which is also referred to as the breakaway range, can be reached in the case of the fan, especially in the case of an axial fan.
  • the air flow breaks off at least partially at the impeller blades of the fan.
  • the fan can no longer maintain the original increase in pressure (compression), pulsations occur, which result in increased vibrations and noise emissions.
  • the fan operates in the stall range, which is referred to herein as the unstable condition of the fan.
  • unstable condition of the fan becomes a condition of the fan understood, at which the stall point is reached, i.e. a stall of the flow from the impeller blades of the fan has taken place.
  • the fan can be brought back into a stable operating state by reducing the necessary pressure.
  • the fan works again without stalling at the impeller blades with higher efficiency, lower vibrations and lower noise emissions.
  • the invention now makes use of the fact that some of the operating parameters of the fan show a special course which is characteristic with regard to the unstable operating state, so that the parameter is used to draw conclusions about an impending or an unstable operating state of the fan that has already occurred.
  • the value and, as will be explained in more detail below, in particular the course of the value of the monitored parameter is therefore an indication that an unstable operating point has been reached. If a limit value is exceeded as a critical value and/or if a characteristic (time) course of the value is identified, this indicates advanced, impermissible deposit formation. Such a limit value or specified critical value defines a specified operating point of the fan in relation to a break point. A characteristic course is also an indication of a stall that has occurred.
  • the monitoring and evaluation of a parameter for the power consumption of the fan is based on the knowledge that the course of the power consumption of the fan shows a characteristic course.
  • This course is characterized by a continuous increase in power consumption due to the increasing formation of deposits up to a maximum (within the stable range), from which point the power consumption then drops to a local minimum or terrace point before it increases again.
  • the range from reaching such a maximum to reaching the terrace point is defined as the transition range.
  • the demolition point becomes present defined by the terrace point. The unstable area is reached when the terrace point is exceeded.
  • vibration parameters are understood to mean all parameters which are characteristic of a vibration caused by the operation of the fan. In particular, these are vibrations of the fan itself, but also vibrations caused by the air flow generated by the fan.
  • the impending or already completed instability of the fan is used as a criterion for detecting impermissible deposit formation.
  • two parameters that are independent of one another are monitored. This means that each of the parameters provides independent information about the current operating status, in particular in relation to the unstable status.
  • the two parameters are preferably the previously mentioned parameters of power consumption (power parameters) and vibration (vibration parameters).
  • the recorded values of these parameters are in particular also related to one another, for example provided with different weighting factors. Overall, a resulting total value is determined from these two parameter values. If this total value determined in this way exceeds a critical value, the critical covering is inferred.
  • a detection unit is generally arranged to detect the values of the parameter.
  • this is an additional sensor.
  • the parameter is, for example, Obtain process data, for example from a controller, in particular an engine controller.
  • a signal input at the control unit with a corresponding processing logic would be the detection unit, which is connected to a corresponding signal output of the engine control.
  • the time profile of the parameter ie in particular the profile of the power consumption or also the profile of the vibration parameter, is preferably evaluated.
  • at least two values of the respective parameter are recorded at different points in time and compared with one another or set in relation to one another.
  • Comparable operating states of the fan are compared with each other. Comparable operating states are understood to mean, in particular, clearly defined power levels of the fan, in which the fan is therefore preferably operated at the identical speed. If the fan is operated with a variable speed, operating states with the same speed are also compared with one another. Due to the variability, sliding parameters and correspondingly adapted critical values should then preferably be used.
  • This qualitative consideration has the particular advantage that external influences, such as climatic influences, component-dependent influences and / or load-dependent influences are automatically taken into account. For example, it does not depend on the specific type of fan or the fan-heat exchanger unit.
  • the absolute characteristic data such as the absolute values for the power consumption (which, for example, may only vary within a predetermined range) are not required for the evaluation and are preferably not used.
  • the method described here is therefore component-independent and is therefore used, for example, for different fans or units, in particular without special adjustments having to be made.
  • the power consumption in particular shows a very characteristic curve with a maximum (in the stable area) and a subsequent local minimum.
  • a maximum in the stable area
  • a subsequent local minimum In order to identify and evaluate these characteristic values, it is generally necessary to evaluate the course, that is to say several individual values. Conventional evaluation algorithms are used for this.
  • the respective parameter is therefore not only monitored with regard to exceeding a limit value. Rather, the course is evaluated with regard to one or more of the criteria: maximum, turning point, minimum, gradient, curvature behavior, etc.
  • the course of the value of the parameter is evaluated after a maximum has been reached.
  • the parameter is monitored and evaluated for a negative slope after a maximum. I.e. if a negative slope is recorded after a maximum, this is evaluated as an indication of the presence of a critical amount.
  • a particular advantage of the evaluation of the course can be seen in the fact that, for example, based on an evaluation of the gradients on the degree of Deposit formation can be ruled out in order to initiate suitable countermeasures early and in good time.
  • continuous or periodically recurring monitoring of the fan parameters is preferably carried out, in particular as part of what is known as condition monitoring, in order to identify possible impermissible deposit formation at an early stage and to be able to take suitable countermeasures in good time.
  • condition monitoring is particularly useful when contamination is deposited, which is removed, for example, as part of inspections.
  • these values are used to draw conclusions about the degree of deposit formation at the current point in time.
  • a measure to remove the deposit is preferably initiated. Different methods are available for this, as they are basically known.
  • Another advantage of the method described here is that not only is icing of the heat exchanger identified, but alternatively and in particular in addition to identifying icing, contamination of the heat exchanger surfaces is also identified.
  • the control unit is therefore designed in such a way that it also identifies such contamination.
  • the value of the parameter is preferably checked before and after a defrosting measure and, in particular, compared with a reference value.
  • the reference value was recorded, for example, when the heat exchanger was commissioned or reflects the typical value of a heat exchanger without deposits. Becomes If such an evaluation is carried out after a defrosting measure, an increase in the parameter, for example an increase in power consumption compared to the original reference, can be used as an indication of dirt deposits.
  • the control unit is preferably set up to check the success of a defrosting measure. For this purpose, after a defrosting process, the current value of the parameter is compared with a reference value for the unloaded state. If there is an impermissible deviation, an improper defrosting process is identified. At least one error signal is given or the defrosting process is restarted.
  • the control unit is preferably designed to distinguish whether there is contamination (deposits of dirt on the heat exchanger surfaces) or whether the defrosting process was improper (icing is still present). For this purpose, for example, the defrosting process is initiated several times and the values are then compared. If there is still an impermissible deviation from the reference value, contamination or a general malfunction is recognized and a message is sent, e.g. with the request to carry out cleaning / maintenance.
  • reference data are stored in the control unit in particular, which indicate a correlation between the parameter and a deposit formation.
  • a reference curve is specifically stored, which shows the course of the parameter depending on the degree of deposit formation.
  • a respective reference value or the profile of the parameter is preferably stored as a criterion for reaching the unstable state. Based on the respective value, it can therefore be read whether and to what extent such an unstable state and thus impermissible deposit formation has been reached or is imminent.
  • the value of the parameter measured during operation is preferably compared with this reference data.
  • a power consumption of the fan is preferably recorded and the power consumption or a variable derived therefrom is evaluated as the parameter to be monitored. On the basis of the current consumption, conclusions can be drawn, in particular, about the power consumption.
  • a sensor is preferably arranged to detect a vibration as a parameter. This is either a vibration sensor, which directly measures mechanical vibrations, or alternatively a sound sensor, which measures acoustic vibrations.
  • a critical covering is identified when a vibration limit value is exceeded.
  • the limit value therefore forms the critical value in this respect.
  • the evaluation of the course over time allows greater accuracy and, in particular, the possibility of predicting when the critical value will be reached. It will therefore, in particular, the vibration characteristics are evaluated over the operating time of the fan.
  • the detected value of the parameter is used to infer the degree of the deposit, ie how many deposits have formed in the meantime. This is done in particular by comparison with the previously mentioned reference data.
  • only the at least one parameter is evaluated to identify the deposit.
  • the method described here for identifying a deposit that is particularly critical is preferably used in a heat pump, in particular in a heat exchanger designed as an evaporator subjected to air.
  • a heat pump 2 according to in 1 The flow diagram of a cyclic process shown comprises a heat exchanger designed as an evaporator 4, a compressor 6, a condenser 8 and a throttle element 10. These four main components of the heat pump 2 are connected to one another via pipes to form a (refrigerant) circuit.
  • the evaporator 4 is designed as an air/refrigerant evaporator and in particular as a lamellar heat exchanger. It generally has heat exchange surfaces 12, which are formed in particular by lamellae.
  • the evaporator 4 is assigned a fan 13 which, for example, together with the evaporator 4 forms a unit with a common housing. Ambient air is drawn in via the fan 13 , which is also referred to as a fan, and then flows through the evaporator 4 . Here, heat is transferred from the ambient air to the refrigerant.
  • the fan 13 has so-called impeller blades, which rotate during operation and generate the air flow.
  • a hot gas line 16 branches off between the compressor 6 and the condenser 8 and opens into the pipeline on the inlet side to the evaporator 4 .
  • a shut-off valve 18 is connected, which is closed in the normal operating state. Before and after the condenser 8 more valves are installed in the pipelines, which are open in the normal operating state.
  • the heat pump 2 includes a control unit 20. This controls the operation of the heat pump 2.
  • the control unit is also provided in particular for controlling a defrosting process for the evaporator 4 .
  • the control unit 20 decides when a defrosting process is required and initiates this if necessary.
  • a so-called hot gas defrosting system is provided for defrosting.
  • the shut-off valve 18 is opened and the evaporator 4 is subjected to the hot gas.
  • another known defrosting method is used, such as reverse cycle, direct electric defrosting.
  • Icing generally a deposit formation on the heat exchanger surfaces 12, leads to an increase in the flow resistance within the evaporator 4. Due to this increased flow resistance, the pressure loss and thus the required head (pressure) of the fan 13 increases, so that the Fan 13 has to do more work and the power consumption of an electric drive motor of the fan 13 increases.
  • the power consumption P is plotted against the volume flow q of the air flow conveyed by the fan 13 .
  • the characteristic curve A shows the situation of an evaporator 13 with coating-free heat exchanger surfaces 12, which are therefore neither dirty nor frosted. This is the case, for example, when the fan 13 is in an initial state or when it is new, or also following a defrosting process.
  • characteristic curve B shows a situation in which a deposit has formed. It is easy to see that with this characteristic curve, the pumped volume flow is reduced and the power consumption is increased at the same time.
  • the pressure loss ⁇ P increases from curve A to curve B, as indicated by the arrow.
  • the characteristic curve A shifts noticeably in the direction of the characteristic curve B.
  • the characteristic curves A, B show two states at different times with a different degree of deposit formation (degree of icing) and in this respect depict a development over time in which a deposit formation takes place.
  • the diagram contains characteristic curves of the power consumption P for different power levels of the fan 13.
  • the different power levels are typically defined by different speeds (degrees of control or control voltage for fans with variable speed), as specified by way of example for some of these characteristic curves.
  • Constant speed fans typically have only one power consumption characteristic.
  • FIGS. 3 and 4 The course of the power consumption P over time is shown qualitatively in FIGS. 3 and 4 as an example.
  • these characteristic curves start from a starting point S, which in particular has an initial or new state clean heat exchanger surfaces 12 defined, a continuous increase in power consumption P due to the formation of deposits during operation.
  • the power consumption P reaches a maximum M and then falls to a local minimum T, which is also referred to as the terrace point.
  • the power consumption P then increases again.
  • the profile within the falling area is also characterized by a turning point W, at which the curvature of the profile changes.
  • the area from the maximum M to the minimum T is defined as the transition area.
  • the area from the minimum T with a (disproportionately) increasing course is defined as an unstable zone (detachment area)
  • the figure 4 is the one in the figure 3 shown qualitative curve of the power consumption P for two different icing scenarios (coating formation scenarios).
  • the two scenarios differ in their rate of deposit formation, ie the deposit forms faster in one scenario than in the other scenario. This results in the unstable range being reached earlier, ie the characteristic values such as the maximum M being reached earlier. Even before the maximum M is reached, the higher deposit formation rate can be seen from a higher slope of the curve.
  • This power consumption P is now used as a parameter for monitoring and identifying a critical deposit.
  • the value of this parameter ie a code number for the current power consumption, for example a motor current of the fan 13, is continuously or periodically recorded by the control unit 20 and evaluated. The course of the value of the parameter is therefore generally recorded and evaluated.
  • the control device 20 emits a signal and, in particular, initiates a defrosting process.
  • a course of the value is preferably considered and this is evaluated with regard to special characteristic values. To step If this occurs, this is identified as a critical deposit and a signal is emitted.
  • the maximum positive slope in the area between the starting point S and the maximum M is compared with the highest negative slope between the maximum M and the turning point W or with the slope between the maximum M and the local minimum T.
  • all of these criteria form (characteristic) values of the monitored parameter, which are used to decide whether a critical pavement thickness is present. At least one of these aforementioned values is preferably monitored. However, several of these (characteristic) values are preferably monitored. If several characteristic values are taken into account, the individual characteristic values are weighted, for example, with a weighting factor and combined to form a common performance characteristic value, which is used to decide whether a measure is to be initiated.
  • a vibration parameter is alternatively and preferably additionally evaluated. With increasing deposit formation, this also changes overall Oscillation behavior of the evaporator system, specifically the evaporator unit formed by fan 13 and evaporator 4. In particular, there is also a characteristic change in the vibration behavior over the operating period with increasing deposit formation. In this respect, the course of a vibration parameter, specifically for the components that are exposed to the air flow, is used as an indicator for the degree of deposit formation.
  • the actual mechanical vibrations of a component specifically the fan assembly, and/or sound vibrations that occur as a result of the vibrations are recorded and evaluated.
  • a sensor 22 is arranged, which transmits its sensor signals to the control unit 20 .
  • the control unit 20 preferably receives the instantaneous values for the power consumption directly from an engine controller, which is not shown in detail here.
  • reference data are stored for the different parameters, specifically for the parameter characterizing the power consumption and/or the vibration parameter, which preferably define an initial state and thus a coating-free, unloaded state.
  • Deposited are, for example, the values of power consumption for different operating states, in particular power levels of the evaporator (eg different control voltages, ie speed of the fan) or also reference vibration values for such different operating states.
  • the instantaneous values are preferably compared with the reference data. This comparison is used in particular to draw conclusions about the current state, for example the degree of the current deposit formation.
  • a set of several reference data subsets is preferably stored, with each subset containing reference data for defined pavement states.
  • each subset containing reference data for defined pavement states.
  • the characteristic curves of the parameters to be monitored are stored as reference data, preferably for different operating states (power levels) of the fan and in particular also as a function of different deposit formation rates (cf. 4 ).
  • a comparison with the reference data preferably takes place after a respective defrosting process has been carried out. This is preferably used to check the effectiveness of the defrosting process that has been carried out. If the values are still above the reference data in an impermissible manner, this is evaluated to the effect that there is still a deposit, for example due to dirt deposits or because the defrosting process was unsuccessful.
  • the defrosting process is preferably carried out again. If the instantaneous values continue to be impermissibly high, contamination or another malfunction is identified.
  • Findings of this kind for example contamination or another fault, lead to notification and reporting to the system operator, for example.
  • control device 20 is therefore also designed for monitoring and evaluating with regard to contamination of the heat exchanger surfaces 12 .
  • the characteristic values then currently recorded are preferably compared with the reference data in a non-deposited state. If the difference is above a critical value, the control unit 20 identifies that there is critical contamination and emits a corresponding signal, for example a request for maintenance and cleaning of the evaporator 4.
  • the method described here ensures that deposits forming, specifically icing, on the heat exchanger surfaces 12 can be detected and removed in a timely and reliable manner, but at the same time only as required. This achieves effective heat transfer and increases the overall system efficiency. At the same time, unwanted noise emissions are avoided. This applies in particular to noise emissions due to increasing pollution. Unnecessary defrosting processes are reliably avoided.
  • a defrosting process is only carried out depending on a (previously defined) degree of deposit formation. i.e. the determination of a defrost point in time is independent e.g. of temperature influences as well as independent of a momentary heat transfer capacity of the evaporator.
  • the defrosting strategy described here is therefore very targeted and leads to improved efficiency of the heat pump. Viewed over the operating period, the defrosting processes are certainly initiated at different heat transfer rates and/or different temperature conditions. Overall, strategies for initiating a defrosting process that are dependent on temperature and runtime are dispensed with in the present case.
  • a defined operating point of the fan in relation to the unstable area is used as the (single) criterion for initiating a defrosting process, i.e. if a defined value is exceeded for the monitored parameter.
  • This defined operating point is preferably selected in such a way that it is before the unstable operating state is reached.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Air Conditioning Control Device (AREA)
EP21213541.2A 2020-12-10 2021-12-09 Dispositif, ainsi que procédé de détection d'un dépôt sur une surface d'échangeur de chaleur Pending EP4012314A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE102020215658.1A DE102020215658A1 (de) 2020-12-10 2020-12-10 Vorrichtung sowie Verfahren zur Erkennung eines Belags auf einer Wärmetauscherfläche

Publications (1)

Publication Number Publication Date
EP4012314A1 true EP4012314A1 (fr) 2022-06-15

Family

ID=78916955

Family Applications (1)

Application Number Title Priority Date Filing Date
EP21213541.2A Pending EP4012314A1 (fr) 2020-12-10 2021-12-09 Dispositif, ainsi que procédé de détection d'un dépôt sur une surface d'échangeur de chaleur

Country Status (2)

Country Link
EP (1) EP4012314A1 (fr)
DE (1) DE102020215658A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4407246A1 (fr) * 2023-01-24 2024-07-31 Vaillant GmbH Procédé d'opération d'une pompe à chaleur, pompe à chaleur et programme informatique

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102022206632A1 (de) 2022-06-30 2024-01-04 Robert Bosch Gesellschaft mit beschränkter Haftung Verfahren zum Betrieb einer Kraftwärmemaschine und eine Kraftwärmemaschine

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3036688A1 (de) 1980-09-29 1982-05-13 Siemens AG, 1000 Berlin und 8000 München Verfahren und vorrichtung zum abtauen von luft-wasser-waermepumpen
DE3110850A1 (de) 1981-03-20 1982-09-30 Küppersbusch AG, 4650 Gelsenkirchen Steuereinrichtung fuer die automatische abtauung eines verdampfers
US4400949A (en) * 1981-03-03 1983-08-30 Mitsubishi Denki Kabushiki Kaisha Frost detector for refrigerating apparatus
DE3441912C2 (de) 1984-11-16 1994-05-05 Fichtel & Sachs Ag Abtausteuerung für eine Wärmepumpe
DE10131379B4 (de) 2001-06-28 2004-08-12 Stiebel Eltron Gmbh & Co. Kg Verfahren zur Steuerung des Abtauens eines Luft/Luft-Wärmetauschers
DE102005034826A1 (de) 2005-07-26 2007-02-22 Glen Dimplex Deutschland Gmbh Wärmepumpe sowie Verfahren zum Betrieb einer Wärmepumpe
DE102006013587B4 (de) 2006-03-22 2016-06-23 Stiebel Eltron Gmbh & Co. Kg Wärmepumpe
JP2016125766A (ja) * 2015-01-05 2016-07-11 三星電子株式会社Ｓａｍｓｕｎｇ Ｅｌｅｃｔｒｏｎｉｃｓ Ｃｏ．，Ｌｔｄ． 冷却装置
US20170176072A1 (en) * 2015-12-21 2017-06-22 Lennox Industries Inc. Intelligent defrost control method
DE102018202971A1 (de) * 2018-02-28 2019-08-29 BSH Hausgeräte GmbH Kältegerät mit Abtauheizung
CN110779264A (zh) * 2019-11-19 2020-02-11 浙江工业大学 基于风机振动和信息融合的除霜控制系统及控制方法

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3036688A1 (de) 1980-09-29 1982-05-13 Siemens AG, 1000 Berlin und 8000 München Verfahren und vorrichtung zum abtauen von luft-wasser-waermepumpen
US4400949A (en) * 1981-03-03 1983-08-30 Mitsubishi Denki Kabushiki Kaisha Frost detector for refrigerating apparatus
DE3110850A1 (de) 1981-03-20 1982-09-30 Küppersbusch AG, 4650 Gelsenkirchen Steuereinrichtung fuer die automatische abtauung eines verdampfers
DE3441912C2 (de) 1984-11-16 1994-05-05 Fichtel & Sachs Ag Abtausteuerung für eine Wärmepumpe
DE10131379B4 (de) 2001-06-28 2004-08-12 Stiebel Eltron Gmbh & Co. Kg Verfahren zur Steuerung des Abtauens eines Luft/Luft-Wärmetauschers
DE102005034826A1 (de) 2005-07-26 2007-02-22 Glen Dimplex Deutschland Gmbh Wärmepumpe sowie Verfahren zum Betrieb einer Wärmepumpe
DE102006013587B4 (de) 2006-03-22 2016-06-23 Stiebel Eltron Gmbh & Co. Kg Wärmepumpe
JP2016125766A (ja) * 2015-01-05 2016-07-11 三星電子株式会社Ｓａｍｓｕｎｇ Ｅｌｅｃｔｒｏｎｉｃｓ Ｃｏ．，Ｌｔｄ． 冷却装置
US20170176072A1 (en) * 2015-12-21 2017-06-22 Lennox Industries Inc. Intelligent defrost control method
DE102018202971A1 (de) * 2018-02-28 2019-08-29 BSH Hausgeräte GmbH Kältegerät mit Abtauheizung
CN110779264A (zh) * 2019-11-19 2020-02-11 浙江工业大学 基于风机振动和信息融合的除霜控制系统及控制方法

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4407246A1 (fr) * 2023-01-24 2024-07-31 Vaillant GmbH Procédé d'opération d'une pompe à chaleur, pompe à chaleur et programme informatique

Also Published As

Publication number Publication date
DE102020215658A1 (de) 2022-06-15

Similar Documents

Publication Publication Date Title
EP4012314A1 (fr) Dispositif, ainsi que procédé de détection d'un dépôt sur une surface d'échangeur de chaleur
DE102011051285B4 (de) Verfahren und Einrichtung zur Vereisungsvermeidungsregelung für Verdampfer einer Wärmepumpe von Klimaanlagen in Fahrzeugen
EP1769147B1 (fr) Procede d'utilisation d'un groupe de turbines a gaz
DE102018205169A1 (de) Verfahren zum Steuern einer Klimatisierungsvorrichtung eines Kraftfahrzeugs und Klimatisierungsvorrichtung für ein Kraftfahrzeug mit einer Wärmepumpeneinheit
EP2508814A1 (fr) Unité d'aération
WO2005115776A1 (fr) Dispositif et procede de surveillance du niveau de refrigerant dans le circuit d'un systeme de climatisation
EP2018985A2 (fr) Climatisation pour véhicule automobile et procédé de contrôle correspondant
DE102007001452A1 (de) Verfahren und Vorrichtung zur Ermittlung einer Kältemittelunterfüllung eines Kältemittelkreislaufs einer Klimaanlage für ein Fahrzeug
EP3019363A1 (fr) Système de commande d'une installation de chauffage-climatisation dans un véhicule automobile
DE19745028A1 (de) Verfahren und Vorrichtung zur verdampfervereisungsgeschützten Klimaanlagensteuerung
DE102012208819B4 (de) Verfahren für die steuerung und regelung von kälteanlagen und wärmepumpen mit luftbeaufschlagtem verdampfer
EP4212786A1 (fr) Procédé de dégivrage d'une grille d'entrée d'air d'un évaporateur d'une pompe à chaleur à air, dispositif pour la mise en oeuvre du procédé et produit programme informatique
EP3882466A1 (fr) Procédé de fonctionnement d'un dispositif de transport de fluide
DE102017204122A1 (de) Verfahren zum Betreiben eines Kältemittelkreislaufs für eine Fahrzeugklimaanlage
DE60107782T2 (de) Verfahren und Vorrichtung zur Überwachung des Füllungszustandes einer Kraftfahrzeugklimaanlage
DE102019125070A1 (de) Verfahren zur Steuerung eines Kältekreislaufs, Kältekreislauf, Wärmemanagementsystem und Fahrzeug
EP2366968B1 (fr) Procédé et dispositif de décongélation d'un évaporateur d'un dispositif de pompe à chaleur
DE102020134027B4 (de) Kälteanlage mit Wärmepumpenfunktion und Steuereinheit zur Vereisungsbestimmung, Betriebsverfahren für und Kraftfahrzeug mit einer solchen Kälteanlage
WO2006021351A1 (fr) Dispositif de controle du niveau de refrigerant dans un systeme refrigerant ou de climatisation
DE102021113802A1 (de) Verfahren und System zum Abtauen eines Kühlaggregats
DE60034016T2 (de) Verfahren zum Regeln eines Klimaanlagekreislaufes mit variablem Verdrängungskompressor
WO2024110022A1 (fr) Procédé de surveillance de l'encrassement d'un échangeur de chaleur d'une pompe à chaleur
DE102007051127A1 (de) Klimaanlage und Verfahren zum Betrieb einer Klimaanlage
DE102023100871A1 (de) Verfahren zum Überwachen von Arbeitsmittelverlust aus einer Wärmepumpe
DE102020110475A1 (de) Verfahren zum Erkennen einer vorliegenden oder drohenden Blockade mindestens eines Strömungswegs

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20221212

RBV Designated contracting states (corrected)

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20240126