Method for monitoring the fouling of a heat exchanger of a heat pump
Patent Information
- Application Number
- DE112022008028
- Authority / Receiving Office
- DE · DE
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2022-11-23
- Publication Date
- 2025-11-06
AI Technical Summary
Conventional heat pumps often operate with dirty heat exchangers for extended periods due to lack of regular visual inspections, leading to decreased efficiency and increased energy consumption, resulting in higher electricity costs.
An automatic method for monitoring heat exchanger contamination in heat pumps, involving data acquisition of energy consumption, fluid temperatures, and pressures, with efficiency determination and contamination assessment to trigger timely cleaning actions.
This method allows for effective and reliable detection of heat exchanger contamination without user effort, preventing energy consumption increases and associated costs by enabling quick cleaning interventions.
Abstract
Description
[0001] Method for monitoring contamination of a heat exchanger of a heat pump
[0002] The present invention relates to a method for monitoring contamination of a heat exchanger of a heat pump and also to a heat pump capable of carrying out such a method.
[0003] For effective heat exchange between the working medium of a heat pump and the useful medium of a thermal object (cooling object or heating object) in a heat pump heat exchanger, the heat exchanger should be as free as possible from dirt (e.g. foreign substances, dust, etc.). As the heat exchanger becomes increasingly contaminated, the effective heat exchange decreases and with it the efficiency of the heat pump, which is why the heat pump has to absorb more electrical energy to achieve the same cooling or heating result. Regularly cleaning the heat exchanger can make the heat pump operate more energy-efficiently. In practice, however, the user only rarely visually inspects the heat exchanger and then cleans it if necessary. This is why conventional heat pumps can operate for very long periods with a dirty heat exchanger, which has a negative impact on energy consumption and the corresponding electricity costs.
[0004] It is therefore the object of the invention to create an effective and reliable measure for the effective heat exchange between a working medium of a heat pump and a useful medium of a thermal object (cooling object or heating object) in a heat exchanger of the heat pump that is as free from dirt as possible.
[0005] This object is achieved by the subject matter of the invention defined in independent claim 1. Some advantageous embodiments and further developments as well as implementations and applications of the invention are the subject matter of the dependent claims.
[0006] According to the invention, an automatic method for monitoring contamination of a heat exchanger of a heat pump is proposed. The heat pump has a working fluid circuit with a conveying device for conveying a working fluid through the working fluid circuit, a drive device for driving the conveying device, and at least one heat exchanger in which the working fluid is in heat exchange with a working fluid of a working fluid circuit for a thermal object (cooling object or heating object).The automatic monitoring method includes the steps of acquiring a plurality of parameter data, which include an energy consumption of the conveying device of the working fluid circuit, a working fluid temperature and / or a working fluid pressure in the working fluid circuit upstream and / or downstream of the at least one heat exchanger, and a working fluid temperature and / or a working fluid pressure in the working fluid circuit upstream and / or downstream of the respective heat exchanger; determining the efficiency of the at least one heat exchanger based on the acquired parameter data; and assessing the degree of contamination of the at least one heat exchanger based on the determined efficiency and the acquired parameter data.
[0007] This automatic heat pump monitoring process allows contamination of at least one heat exchanger of the heat pump to be detected effectively and reliably (promptly and correctly) without any additional effort on the part of the user (e.g. without visual inspections). The user and / or a device can then react quickly to contamination of the at least one heat exchanger detected by this automatic process with appropriate cleaning in order to quickly restore effective heat exchange between the working medium of the heat pump and the useful medium of the respective thermal object (cooling object or heating object). This also prevents or at least temporarily offsets an increase in the heat pump's energy consumption and the corresponding electricity costs. Depending on the application, the heat pump can be used, for example, as a refrigeration system or as a heating system.
[0008] Preferably, the method further comprises processing the acquired parameter data to generate additional indication data (e.g., correlation values and / or amplitudes) of the energy consumption of the conveying device. Determining the efficiency based on the acquired parameter data and the generated additional indication data and assessing the degree of contamination based on the determined efficiency and the acquired parameter data and / or the generated additional indication data then lead even more reliably to correct determinations and assessments. Preferably, this automatic method further comprises outputting (e.g., optically, acoustically, and / or digitally) an indication to a user indicating contamination of the at least one heat exchanger if the assessed degree of contamination exceeds a predetermined limit.Alternatively or additionally, this automatic method may further include initiating an automatic cleaning activity if the assessed level of soiling exceeds a predetermined limit.
[0009] In one embodiment of the invention, the determination of efficiency and the assessment of the degree of contamination are carried out by a computer-assisted method which is set by a user and / or by artificial intelligence.
[0010] Since the working fluid circuit is a closed system and the pressure of the working fluid is related to the temperature of the working fluid, the temperature and / or pressure of the working fluid can be recorded as parameter data. Since the working fluid circuit is generally a closed system and the pressure of the working fluid is related to the temperature of the working fluid, the temperature and / or pressure of the working fluid can also be recorded as parameter data. Since the energy consumption of the working fluid conveying device is influenced by the refrigerant pressure and the refrigerant temperature, the parameter data of the energy consumption of the conveying device of the working fluid circuit can preferably be determined by retrieving the required electrical energy to drive the conveying device (e.g.by a corresponding control of the drive device of the conveying device) and / or detecting a temperature or pressure of the working fluid upstream of the conveying device. Furthermore, the parameter data of the energy consumption of the conveying device of the working fluid circuit are preferably recorded as time-dependent parameter data.
[0011] According to a further aspect of the invention, a heat pump includes a working fluid circuit which includes a conveying device for conveying a working fluid through the working fluid circuit, a drive device for driving the conveying device, and at least one heat exchanger in which the working fluid is in heat exchange with a useful fluid of a useful fluid circuit for a thermal object (cooling object or heating object);a plurality of sensors for detecting parameter data, which include: a first sensor for detecting an energy consumption of the conveying device of the working medium circuit, at least one second sensor for detecting a working medium temperature and / or a working medium pressure in the working medium circuit upstream and / or downstream of the at least one heat exchanger and at least one third sensor for detecting a working medium temperature and / or a working medium pressure in the working medium circuit upstream and / or downstream of the respective heat exchanger;and an evaluation unit connected to the plurality of sensors and configured to carry out the automatic method according to the invention for monitoring contamination of the at least one heat exchanger. The first sensor system for detecting the energy consumption of the conveying device of the working fluid circuit can, for example, comprise a control unit for operating the drive device of the conveying device, from which the electrical energy required to drive the conveying device can be retrieved, and / or a circuit sensor for detecting a temperature or pressure of the working fluid upstream of the conveying device.
[0012] This heat pump according to the invention achieves the same advantages as the automatic monitoring method according to the invention. Regarding the advantages and explanations, reference is therefore also made to the advantages and explanations explained above with regard to the method.
[0013] The heat pump preferably further comprises an output element connected to the evaluation unit and configured to output an indication of contamination of the at least one heat exchanger (e.g., visually, acoustically, and / or digitally). Alternatively or additionally, the heat pump may further comprise an automatically activated automatic cleaning device.
[0014] In one embodiment of the invention, the evaluation unit contains a computer-assisted method configured to determine the efficiency and corresponding degree of contamination of the at least one heat exchanger based on the acquired parameter data and the generated additional reference data. This computer-assisted method can be set by a user and / or by artificial intelligence. The evaluation unit for performing contamination monitoring of the at least one heat exchanger and a control unit for controlling the drive device for the conveying device can preferably be integrated into a common controller.
[0015] The invention also relates to an electronic device (for example, a household appliance, a commercial appliance, or a vehicle device) comprising a heat pump according to the invention as described above and at least one thermal object (cooling object or heating object) whose working fluid circuit is in heat exchange with the working fluid circuit in the at least one heat exchanger of the heat pump. The electronic device can be, for example, a laundry treatment appliance, a refrigerator and / or freezer, an oven, a dishwasher, an air conditioner, or the like.
[0016] The invention is defined by the appended claims. The above and other features and advantages of the invention will become more apparent from the following exemplary description of preferred, non-limiting embodiments with reference to the accompanying drawings. These show, partly schematically:
[0017] Fig. 1 shows the basic structure of an embodiment of a heat pump according to the invention; and
[0018] Fig. 2 is a flowchart of an embodiment of a method for monitoring contamination of a heat exchanger of the heat pump according to the invention.
[0019] Referring to Fig. 1, an embodiment of a heat pump according to the invention is explained by way of example in the form of a refrigeration system for a refrigerated object. Alternatively, this heat pump can also be used as a heating system for a heated object. The thermal object can, for example, be a unit of a household appliance, such as a laundry appliance, a refrigerator and / or freezer, an oven, a dishwasher, an air conditioner, etc.
[0020] The heat pump 10 has a working fluid circuit 12 for a working fluid (e.g.
[0021] Refrigerant R134a), which has a working fluid conveying device 14 in the form of a compressor or compressor along the working fluid line 13, a high-pressure side heat exchanger 16 in the form of a condenser or condenser, an expansion element 17 in the form of an expansion valve or throttle, and a low-pressure side heat exchanger 18 in the form of an evaporator. The gaseous working fluid is first compressed in the compressor 14 and then liquefied in the condenser 16, releasing heat, for example, to the environment. The liquefied working fluid is then expanded through the expansion valve 17. In the subsequent evaporator 18, the working fluid evaporates at a low temperature, absorbing heat, and is then compressed again in the compressor 14.
[0022] At the evaporator 18, the working fluid circuit 12 exchanges heat with a working fluid circuit 32 of a cooling object 30, for example, in the form of a cold storage room. As indicated in Fig. 1, the working fluid circuit 32 contains, in the region of the evaporator 18, at least one working fluid conveyor 34a, 34b upstream or downstream of the evaporator 18 for conveying the working fluid (e.g., cold air flow) through the evaporator, and preferably also at least one temperature sensor 36a, 36b upstream or downstream of the evaporator.
[0023] As shown in Fig. 1, the heat pump 10 further includes a control unit 20a for regulating the operation of the components 14, 16, 17, 18 of the working fluid circuit 12 and preferably also of the at least one useful fluid conveyor 34a, 34b of the useful fluid circuit 32. The control unit 20a is connected, for example, to a plurality of circuit sensors 23, 24, 27, 28 for detecting the temperature and / or pressure of the working fluid at various points in the working fluid circuit 12 and also to the at least one temperature sensor 36a, 36b of the useful fluid circuit 32 for detecting the temperature of the useful fluid (in each case wirelessly or wired). Based on the obtained parameters, the control unit 20a controls, in particular, a drive device 22 for operating the compressor 14 in order to regulate the cooling capacity of the working fluid circuit 12 in order to meet the cooling demand of the cooling object 30.
[0024] As shown in Fig. 1, the heat pump 10 also contains an evaluation unit 20b for monitoring contamination of the evaporator 18. This evaluation unit 20b is connected to several sensors for detecting parameter data: (a) a first sensor for detecting energy consumption (current and / or voltage) of the compressor 14 of the working medium circuit 12, which is formed by the control unit 20a for retrieving the required electrical energy to drive the compressor 14 and / or the circuit sensor 23 at the compressor 14 for detecting the temperature or pressure of the working medium upstream of the compressor 14, (b) a second sensor for detecting the working medium temperature and / or the working medium pressure in the working medium circuit 12 upstream of the evaporator 18, which is formed by the circuit sensor 24 at the expansion element 17 for detecting the temperature or pressure of the working medium upstream of the evaporator 18 is formed,and (c) a third sensor system for detecting the useful medium temperature and / or the useful medium pressure in the useful medium circuit 32, which is formed by the temperature sensor 36a upstream of the evaporator 18 and / or the temperature sensor 36b downstream of the evaporator 18 in the useful medium circuit 32.
[0025] The evaluation unit 20b is preferably also connected to an output element 26, with which an indication of an assessed level of contamination of the evaporator 18 can be output. Depending on the structure of the output element 26, the indication can be output to the user of the heat pump 10, for example, visually and / or acoustically. Optionally, the indication can also be output digitally, i.e., for example, wirelessly or via a network to a user device (e.g., mobile phone). Optionally, the evaluation unit 20b can alternatively or additionally be connected to a device (not shown) for automatic cleaning, the activity of which can be controlled / executed automatically.
[0026] In addition, the evaluation unit 20b preferably contains a computer-assisted method 25 for determining the efficiency of the evaporator 18 and for assessing the corresponding degree of contamination of the evaporator 18, wherein this computer-assisted method 25 can be set by a user and / or even by artificial intelligence.
[0027] As shown in Fig. 1, the control unit 20a for the drive device 22 of the conveyor device 14 and the evaluation unit 20b for evaluating the acquired parameter data are preferably integrated in a common controller 20. Alternatively, the control unit 20a and the evaluation unit 20b can also be contained in separate controllers, wherein the separate controllers are then preferably connected to one another. As explained above, in the exemplary embodiment of Fig. 1, a cooling object 30 for cooling the working medium by the working medium is coupled to the evaporator 18 of the working medium circuit 12. As indicated in Fig. 1, alternatively or additionally, a heating object 31 for heating the working medium by the working medium can be coupled to the condenser 16 of the working medium circuit 12.
[0028] Referring to Fig. 2, the inventive automatic method 100 for monitoring the contamination of the evaporator 18 of the heat pump 10 explained above and illustrated in Fig. 1 will now be explained.
[0029] In a first step S110, several parameter data items of the heat pump 10 are recorded. As already explained above, the first sensor detects the energy consumption of the compressor 14 of the working fluid circuit 12, the second sensor detects the working fluid temperature and / or the working fluid pressure in the working fluid circuit 12 upstream of the evaporator 18, and the third sensor detects the working fluid temperature and / or the working fluid pressure in the working fluid circuit 32. The recorded parameter data are then received by the evaluation unit 20b. Optionally or preferably, at least the parameter data of the energy consumption of the compressor 14 are recorded as time profiles of the parameter data, which allows the subsequent steps to be carried out more efficiently.
[0030] In an optional second step S112, which supports better evaluation and is therefore preferably present, additional reference data on the energy consumption of the compressor 14 is generated from the acquired parameter data. Since the signal curves of the energy consumption data change depending on the state of the working fluid on the compressor 14, this processing of the acquired parameter data includes, for example, calculating a linear relationship between the energy signals from two consecutive data coils. For example, the correlation, correlation coefficient, and covariance of the individual energy consumption data are calculated. Furthermore, the energy consumption signal can be Fourier transformed to determine the maximum amplitude.
[0031] In a third step S114, the computer-assisted method 25 of the evaluation unit 20b then determines the efficiency of the evaporator 18 based on the acquired parameter data and the generated additional reference data. Due to the additional reference data, this determination is even more reliable than based solely on the acquired parameter data. A change in the energy consumption of the compressor 14 is not necessarily considered a change in the heat exchange efficiency of the evaporator 18 if, for example, the working fluid temperature upstream of the evaporator has changed. The heat exchange efficiency of the evaporator 18 is thus determined based on the energy consumption data, in particular taking into account the generated additional references, in combination with the other parameter data relating to the temperatures or pressures of the working fluid and / or the working fluid upstream of the evaporator 18.
[0032] In a fourth step S116, the degree of contamination of the evaporator is then determined by the computer-assisted method 25 of the evaluation unit 20b based on the determined heat exchange efficiency in combination with the acquired parameter data and the generated additional reference data. In the method, the data relating to the heat exchange efficiency are labeled according to the degree of contamination, so that the appropriately trained computer-assisted method (by the user or manufacturer, or even by artificial intelligence) can also determine the degree of contamination based on the determined efficiency. If the degree of contamination exceeds a predetermined limit, this is then assessed as contamination of the evaporator 18.
[0033] If no contamination of the evaporator is assessed, the monitoring method 100 is continued from the first step S110.
[0034] However, if contamination of the evaporator 18 has been assessed in step S116, a corresponding indication indicating the contamination of the evaporator 18 is output via the output element 26 (e.g. optically, acoustically and / or digitally) in a fifth step S118.
[0035] This notification, which is issued by the heat pump's automatic monitoring process, allows the user to initiate / carry out cleaning of the heat pump 10, in particular of the dirty evaporator 18, very shortly after the evaporator 18 has become dirty, without any additional effort (e.g., without regular visual inspections). Optionally, alternatively or additionally, an activity to initiate automatic cleaning can also be controlled / executed. By cleaning shortly after the contamination has occurred, effective heat exchange between the working medium of the heat pump 10 and the useful medium of the cooling object 30 is very quickly and reliably ensured, whereby an increase in the energy consumption of the heat pump 10 and the corresponding electricity costs can be avoided or at least temporarily offset.
[0036] The invention is defined by the appended claims. The exemplary embodiments explained above serve only to facilitate a better understanding of the invention, but are not intended to limit the scope of protection defined by the claims. As will be apparent to those skilled in the art, other embodiments are also possible within the scope of the invention, in particular by omitting individual features from or adding additional features to the exemplary embodiments described above.
[0037] REFERENCE NUMBER LIST
[0038] 10 Heat pump (as cooling or heating system)
[0039] 12 Working fluid cycle
[0040] 13 Work equipment line
[0041] 14 Conveying device, especially compressor
[0042] 16 high-pressure side heat exchangers, especially condensers
[0043] 17 Expansion device, especially expansion valve / throttle
[0044] 18 low-pressure side heat exchanger, especially evaporator
[0045] 20 Control
[0046] 20a Control unit for operation of the conveyor device
[0047] 20b Evaluation unit for monitoring procedures
[0048] 22 drive device for 14
[0049] 23 Circuit sensor for temperature / pressure of the working fluid upstream of 14
[0050] 24 Circuit sensor for temperature / pressure of the working fluid upstream of 18
[0051] 25 computer-assisted procedure in 20b
[0052] 26 Output element
[0053] 27 additional circulatory sensor
[0054] 28 additional circulatory sensors
[0055] 30 thermal object (cooling object at 18)
[0056] 31 thermal object (heating object at 16)
[0057] 32 Resource cycle
[0058] 34a Upstream material conveyor 16 / 18
[0059] 34b Utility conveyor downstream 16 / 18
[0060] 36a Temperature sensor upstream 16 / 18
[0061] 36b Temperature sensor downstream 16 / 18
Claims
AMENDED CLAIMS received by the International Bureau on 4 August 2023 (04.08.2023) 1. An automatic method (100) for monitoring contamination of a heat exchanger (16, 18) of a heat pump (10), wherein the heat pump (10) has a working fluid circuit (12) with a conveying device (14) for conveying a working fluid through the working fluid circuit (12), a drive device (22) for driving the conveying device (14), and at least one heat exchanger (16, 18) in which the working fluid is in heat exchange with a useful fluid of a useful fluid circuit (32) for a thermal object (30, 31), the method comprising detecting (S110) a plurality of parameter data;wherein the plurality of parameter data to be recorded contain an energy consumption of the conveying device (14) of the working medium circuit (12), and contain a working medium temperature and / or a working medium pressure in the working medium circuit (12) upstream and / or downstream of the at least one heat exchanger (16, 18), and contain a useful medium temperature and / or a useful medium pressure in the useful medium circuit (32) upstream and / or downstream of the respective heat exchanger (16, 18); and wherein the method (100) further comprises:; Processing (S112) the acquired parameter data to generate additional reference data of the energy consumption of the conveying device (14); determining (S114) the efficiency of the at least one heat exchanger (16, 18) based on the plurality of acquired parameter data and the generated additional reference data; and Assessing (S116) the degree of contamination of the at least one heat exchanger (16, 18) based on the determined efficiency and the plurality of acquired parameter data and the created additional indication data.
2. The method (100) according to claim 1, further comprising outputting (S118) an indication to a user indicating contamination of the at least one heat exchanger (16, 18) if the assessed degree of contamination exceeds a predetermined limit value. AMENDED SHEET (ARTICLE 19) Method (100) according to claim 1 or 2, wherein the determination of the efficiency (S114) and the assessment of the degree of contamination (S116) are carried out by a computer-assisted method (25), wherein the computer-assisted method (25) is set by a user and / or even by artificial intelligence. Method (100) according to one of claims 1 to 3, wherein the parameter data of the energy consumption of the conveying device (14) of the working medium circuit (12) are acquired by retrieving the electrical energy required to drive the conveying device (14) and / or by detecting a temperature or a pressure of the working medium upstream of the conveying device (14). Method (100) according to one of claims 1 to 4, wherein the parameter data of the energy consumption of the conveying device (14) of the working medium circuit (12) are acquired as temporal profiles of the parameter data.A heat pump (10), comprising: a working fluid circuit (12), which has: a conveying device (14) for conveying a working fluid through the working fluid circuit (12), a drive device (22) for driving the conveying device (14), and at least one heat exchanger (16, 18) in which the working fluid is in heat exchange with a useful fluid of a useful fluid circuit (32) for a thermal object (30, 31); a plurality of sensors (20a, 23, 24, 36a, 36b) for detecting parameter data, which include: a first sensor (20a, 23) for detecting an energy consumption of the conveying device (14) of the working fluid circuit (12), at least one second sensor (24) for detecting a working fluid temperature and / or a working fluid pressure in the working fluid circuit (12) upstream and / or downstream of the at least one heat exchanger (16, 18), and. AMENDED SHEET (ARTICLE 19) at least one third sensor system (36a, 36b) for detecting a useful medium temperature and / or a useful medium pressure in the useful medium circuit (32) upstream and / or downstream of the respective heat exchanger (16, 18); and an evaluation unit (20b) connected to the plurality of sensor systems (20a, 23, 24, 36a, 36b) and configured to carry out the automatic method (100) for monitoring contamination of the at least one heat exchanger (16, 18) according to one of claims 1 to 5. The heat pump (10) according to claim 6, further comprising an output element (26) connected to the evaluation unit (20b) and configured to output an indication of contamination of the at least one heat exchanger (16, 18).Heat pump (10) according to claim 6 or 7, wherein the evaluation unit (20b) contains a computer-assisted method (25) which is configured to determine the efficiency and the corresponding degree of contamination of the at least one heat exchanger (16, 18) based on the plurality of acquired parameter data and the created additional indication data, wherein the computer-assisted method (25) is adjustable by a user and / or even by artificial intelligence.Heat pump (10) according to one of claims 6 to 8, wherein the first sensor system (20a, 23) for detecting the energy consumption of the conveying device (14) of the working medium circuit (12) comprises a control unit (20a) for operating the drive device (22) of the conveying device (14), from which the electrical energy required to drive the conveying device can be retrieved, and / or a circuit sensor (23) for detecting a temperature or a pressure of the working medium upstream of the conveying device (14). Heat pump (10) according to one of claims 6 to 9, wherein the evaluation unit (20b) for monitoring the contamination of the at least one heat exchanger (16, 18) and a control unit (20a) for controlling the drive device (22) for the conveying device (14) are integrated in a common controller (20). AMENDED SHEET (ARTICLE 19) Electronic device, comprising: a heat pump (10) according to one of claims 6 to 10; and at least one thermal object (30, 31), the working medium circuit (32) of which is in heat exchange with the working medium circuit (12) in the at least one heat exchanger (16, 18) of the heat pump (10). AMENDED SHEET (ARTICLE 19)