Range hood and self-cleaning control method thereof

Abstract

The application discloses an extractor hood and a self-cleaning control method thereof, the extractor hood comprising a fan system and a cleaning device for cleaning the fan system, the cleaning device comprising a waterway device, the waterway device comprising a heating module for heating a cleaning medium and a nozzle for spraying the cleaning medium flowing out of the heating module to the fan system for cleaning; the waterway device further comprises a heat exchanger, the heat exchanger being arranged upstream of the heating module on a cleaning medium flow path; the cleaning device further comprises a heat pump device, the heat pump device comprising an evaporator, a condenser and a compressor forming a loop, and the condenser being used for providing a heat source for the heat exchanger. Compared with the prior art, the application has the advantages that the heat pump technology is adopted, the heat pump technology has a relatively high energy efficiency, the heat in the air is utilized, and the energy-saving effect is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to an oil fume purification device, in particular to an extractor hood and a self-cleaning control method of the extractor hood. BACKGROUND

[0002] The extractor hood has become one of the indispensable kitchen household appliances in modern families. The extractor hood works by using the principle of fluid dynamics, and uses a filter screen to filter part of the oil particles through a fan system installed inside the extractor hood to suck and exhaust the oil fume. The fan system is usually a centrifugal fan, which includes a volute, an impeller installed in the volute, and a motor driving the impeller to rotate. When the impeller rotates, a negative pressure suction is generated at the center of the fan, which sucks the oil fume below the extractor hood into the fan, and then accelerates the oil fume to be collected and guided by the volute and discharged outdoors.

[0003] After long-term use of the extractor hood, a large amount of oil dirt will accumulate inside the fan system, causing the impeller to increase in weight, resulting in a decrease in air volume, an increase in noise, and a decrease in the effect of sucking oil fume. Even if the oil dirt accumulates for a long time and deteriorates, it will produce an odor and affect the kitchen environment. The current main cleaning technologies are door-to-door cleaning service, steam cleaning, hot water cleaning, and heating melting technology. The cleaning object is mainly the impeller, and the volute is less cleaned.

[0004] The above-mentioned cleaning methods have the following disadvantages:

[0005] 1) Door-to-door cleaning service: additional costs are required for cleaning, and the extractor hood needs to be disassembled. After disassembly and reassembly, sometimes the assembly is not in place, resulting in machine failure, noise, and poor smoke suction effect. In addition, the cleaning usually uses strong alkali solution, which will cause damage to the operator and the machine;

[0006] 2) Steam cleaning: steam cleaning often needs an additional heating module to heat the water until steam is generated. In order to generate steam, a high-power heater with an intermittent water supply program must be used to ensure the generation of steam. In the case of low water temperature, a long time is needed to heat the water to generate steam. The conventional technology is a timing mode of supplying water for a seconds and stopping for b seconds, which does not change with the water temperature, resulting in the heating module being unable to adapt to the water temperature in winter and summer, and the steam not being generated or the steam purity being insufficient, so that the cleaning effect is poor. In order to ensure the rapid generation and purity of steam, a large power is often used, which consumes a large amount of electricity and causes a large load on the power supply board, which is prone to overload. Moreover, pure steam cleaning has a large cleaning intensity, but the cleaning distance is limited and cannot act on the volute.

[0007] 3) Hot water cleaning: hot water cleaning uses continuous water jets to clean the impeller. In order to quickly heat the water passing through the cavity, a large power heating module is also needed, which causes problems of high power consumption and heavy load on the power supply board. In addition, the water jet cleaning intensity is poor.

[0008] 4) heating and melting: using high-power heating wires, and not directly acting on the impeller, melting the impeller oil stains through heat radiation, the effect is worse, and there is no medium directly acting on the cleaning surface, only through heating conduction and radiation to melt oil, and the energy consumption is increased.

[0009] Therefore, the cleaning technology of the range hood still needs to be further improved. SUMMARY

[0010] The first technical problem to be solved by the present application is to provide a range hood which can reduce the requirement for the power of the heating module and achieve energy saving.

[0011] The second technical problem to be solved by the present application is to provide a self-cleaning control method applied to the range hood.

[0012] The technical solution adopted by the present application to solve the first technical problem is a range hood comprising a fan system and a cleaning device for cleaning the fan system, the cleaning device comprising a waterway device, the waterway device comprising a heating module for heating a cleaning medium and a nozzle for spraying the cleaning medium flowing out of the heating module to the fan system for cleaning, characterized in that:

[0013] The waterway device further comprises a heat exchanger, which is arranged upstream of the heating module in the flow path of the cleaning medium.

[0014] The cleaning device further comprises a heat pump device, the heat pump device comprising an evaporator, a condenser and a compressor forming a loop, and the condenser is used to provide a heat source for the heat exchanger.

[0015] The heat pump technology is adopted, and the heat pump technology has high energy efficiency, which is equivalent to 3-4 times of electric energy heating using one part of electricity, and utilizes the heat in the air to achieve the effect of energy saving. The heat pump technology itself is energy-saving, and after heating the water, the heating module generates steam, which reduces the requirement for the power of the heating module. The power of the heater is low, and the overall energy-saving effect is achieved, and the load of the power board is greatly reduced.

[0016] In order to provide the cleaning medium, the waterway device further comprises a water storage box for storing the cleaning medium and a water pump, the water storage box and the water pump are connected through a water inlet pipe, the outlet of the water pump is connected to the heat exchanger through a first water pipe, the heat exchanger and the water storage box are further connected through a water return pipe, and the heat exchanger is selectively communicated with the heating module and the water storage box.

[0017] In order to realize the switching of the water path at the heat exchanger in the water path device, the water path device further comprises a first valve, the liquid outlet of the heat exchanger is connected with the liquid inlet of the first valve through a second connecting water pipe, the liquid outlet of the first valve is connected to the liquid inlet of the heating module through a third connecting water pipe and is connected to the water storage box through a backwater pipe, so that the heat exchanger is selectively communicated with the heating module and the water storage box.

[0018] In order to improve the heat exchange efficiency, the heat exchanger is a copper pipe arranged in a cycle and equidistance manner and is clamped in the middle of the condenser.

[0019] Further, the fan system comprises a volute and an impeller, and the condenser is arranged at the bottom of the volute, so that the grease in the volute can be heat-dissolved.

[0020] In order to utilize the condensed water generated by the evaporator for cleaning the volute, the water path device further comprises a condensed water box for collecting the condensed water formed by the evaporator, and the liquid outlet of the condensed water box is connected with the water storage box.

[0021] In order to avoid the constant communication between the condensed water box and the water storage box from affecting the cleaning of the impeller, the water path device further comprises a second valve arranged between the condensed water box and the water storage box, so that the condensed water box and the water storage box are communicated or disconnected.

[0022] Further, the heat pump device further comprises a fan for sucking the air outside the range hood and blowing it to the evaporator, since the fan of the heat pump device can act on the evaporator with the hot air in the kitchen, the evaporator absorbs heat, so that the heat pump device can reduce the temperature in the kitchen.

[0023] Further, the heat pump device further comprises an expansion valve, the liquid outlet of the condenser is connected with the liquid inlet of the expansion valve, the liquid outlet of the expansion valve is communicated with the liquid inlet of the evaporator, and the expansion valve is used for controlling the refrigerant flow in the cycle system to realize the purpose of throttling and create conditions for evaporation.

[0024] The technical scheme adopted by the present application to solve the second technical problem is as follows: a self-cleaning control method of the range hood, comprising the following steps:

[0025] 1) starting, starting the self-cleaning function of the range hood;

[0026] 2) operating the heat pump device;

[0027] 3) operating the water pump, at this time, the heat exchanger and the water storage box are communicated, the cleaning medium is sent from the water storage box to the heat exchanger through the water pump, exchanges the heat in the condenser, and then is sent back to the water storage box through the backwater pipe;

[0028] 4) detecting the temperature of the backflow cleaning medium in the water storage box as T, judging whether T≥B1℃ is established, wherein B1 is a preset first temperature threshold, if yes, entering step 4.1), if no, entering step 4.2):

[0029] 4.1) reading the continuous running time t of the range hood and the cumulative running time t0, then judging whether t≥t0 is established, wherein t0 is a preset continuous running time threshold that needs cleaning, if yes, entering step 5), if no, judging whether t0≥t00 is established, wherein t00 is a preset cumulative running time threshold that needs cleaning, if yes, entering step 5), if no, entering step 6); wherein the continuous running time refers to the time accumulation value of the range hood after the last cleaning, and the cumulative running time refers to the running time accumulation value of the range hood after the last cleaning;

[0030] 4.2) judging whether the heating efficiency needs to be required, if no, returning to step 3), if yes, entering step 4.1);

[0031] 5) entering the steam cleaning mode, at this time, the heat pump device is closed, the cleaning medium is heated into steam through the heating module, and after the steam cleaning runs for a preset time, step 7) is entered;

[0032] 6) entering the hot cleaning medium cleaning mode, at this time, the heat pump device is closed, the cleaning medium is heated to meet the required temperature B1℃ of liquid cleaning through the heating module, and after running for a preset time, step 7) is entered;

[0033] 7) the water pump is continuously operated, and cleaning is performed through the heating module and the nozzle;

[0034] 8) judging whether the cleaning medium in the water pump is used up, if yes, stopping running, if no, returning to step 7).

[0035] The self-cleaning control method of the application has the advantages of the heat pump device itself, and comprehensively judges the pollution time to match the cleaning intensity, so that the energy is not wasted as much as possible on the basis of ensuring the cleaning degree, and the waste of electric energy and the accelerated damage to the module life caused by using the same strong cleaning mode are avoided.

[0036] Further, in step 2), the heat pump device is operated, and after a certain time delay, step 3) is entered, so that the condenser is preheated, the condenser is first brought to the rated temperature, the low-efficiency heat exchange in the early stage is avoided, and the efficiency is improved.

[0037] Further, the fan system includes an impeller, in step 5), the cleaning object of the steam cleaning is the impeller, and the following steps are included:

[0038] 5.1) The heat pump device is turned off, the temperature T of the cleaning medium in the current water storage box is detected and recorded;

[0039] 5.2) The fan system is operated at a first rotating speed;

[0040] 5.3) The heat exchanger and the heating module are connected, and the heat exchanger and the water storage box are disconnected;

[0041] 5.4) After a time delay of a seconds, the water pump stops operating;

[0042] 5.5) The heating module operates until it is heated to a preset second threshold B2℃, B2>B1, so that the cleaning medium is heated into steam;

[0043] 5.6) The nozzle sprays steam to clean the fan system;

[0044] 5.7) The water pump is cyclically operated;

[0045] 5.8) The steam mode operates for a preset time, and then enters step 7).

[0046] Steam generation adopts dynamic intermittent parameter adjustment, and steam generation parameters are adjusted autonomously according to water temperature; or constant parameters are adopted when the heating by the heat pump reaches a constant temperature; the problems of no steam generation or insufficient purity are avoided, and the cleaning effect is ensured.

[0047] Further, in order to generate continuous steam and keep the steam purity at a certain level, in step 5.7), the water pump is cyclically operated for b seconds and stopped for c seconds, and the cycle is repeated, b is a parameter related to the water pump flow, and the cleaning medium fills the heating module and does not pass through the nozzle within the time b, and the following relationship is satisfied:

[0048]

[0049] Q is the actual flow of the water pump installed in the entire waterway device, P is the power of the heating module, η is the heating module, and T is the temperature of the cleaning medium in the water storage box.

[0050] Further, the fan system includes an impeller, in step 6), the cleaning object is the impeller, and the following cleaning steps are included:

[0051] 6.1) The heat pump device is turned off, the temperature T of the cleaning medium in the current water storage box is detected and recorded, and whether t≥B1℃ is determined, if yes, step 6.2) is entered, if no, the heating module is started until T≥B1℃ is established, and step 6.2) is entered;

[0052] 6.2) The fan system is operated at a first rotating speed;

[0053] 6.3) make the heat exchanger and the heating module communicate, and make the heat exchanger and the water storage box disconnect;

[0054] 6.4) the nozzle sprays the cleaning medium to clean the fan system.

[0055] Further, the fan system comprises a volute and an impeller arranged in the volute, and the cleaning objects of steps 5) and 6) are the impeller; the water channel device further comprises a condensate box for collecting the condensate water formed by the evaporator, and the liquid outlet of the condensate box is connected with the water storage box;

[0056] After step 8), the following steps are further included:

[0057] 9) the heating module stops running, and the water pump stops running;

[0058] 10) the heat exchanger and the heating module disconnect and communicate with the water storage box;

[0059] 11) it is judged whether the cleaning medium in the condensate box is full, if yes, the volute is cleaned, and if no, the impeller is spun dry.

[0060] For cleaning the volute, the condensate water accumulated by the evaporator is used, which avoids that the condensate water occupies the volume of the oil cup, resulting in that the cleaning cycle of the oil cup is shortened, and the condensate water can be used to clean the volute regularly, so that the same water can complete the cleaning of the impeller and the volute, and the user does not need to add water again.

[0061] Further, the specific steps of cleaning the volute are as follows, in step 11), if yes, step 12) is entered, so that the condensate box and the water storage box communicate;

[0062] 13) it is judged whether the cleaning medium of the condensate box is released, if yes, step 14) is entered, and if no, step 12) is returned;

[0063] 14) the cleaning of the volute is started:

[0064] 14.1) the condensate box and the water storage box are disconnected, and the heat pump device runs;

[0065] 14.2) the water pump is started to run, and then it is judged whether the temperature T≥B1℃ of the cleaning medium returned by the water storage box is true, if yes, step 14.3) is entered, if no, it is judged whether the heating efficiency meets the requirement, if yes, step 14.3) is entered, if no, the step is repeated;

[0066] 14.3) the heat pump device is closed, the heating module runs, and the fan system runs at a second rotating speed, the second rotating speed is greater than the first rotating speed;

[0067] 14.4) During cleaning, connect the heat exchanger and heating module while disconnecting them from the water storage box;

[0068] 14.5) The nozzle sprays the cleaning medium to clean the volute;

[0069] 14.6) The water pump continues to operate, and the cleaning medium heated by the heat pump device is reheated by the heating module;

[0070] 14.7) Determine if the cleaning medium in the water pump has been used up. If yes, end the cleaning of the volute. If no, return to step 14.6.

[0071] Furthermore, after the volute is cleaned or if the volute cleaning is skipped, the impeller is spun dry and all parameters are set to zero. Specifically, this includes the following steps: after determining in step 14.7) that the cleaning medium in the water pump is used up, proceed to step 15), where the heating module stops running, the water pump stops running, and the volute cleaning ends.

[0072] 16) The heat exchanger is disconnected from the heating module but reconnected to the water storage box for reset;

[0073] 17) The fan system uses a third rotational speed for impeller drying, which is greater than the second rotational speed;

[0074] 18) Turn off self-cleaning mode, set the cumulative runtime t0 and continuous runtime t to zero, and end.

[0075] Compared with existing technologies, the advantages of this invention are as follows: It employs heat pump technology, which has high energy efficiency; using one unit of electricity is equivalent to heating 3-4 times the amount of electricity, utilizing the heat in the air to achieve energy savings. The heat pump technology itself is energy-efficient; water is heated first, and then a heating module heats it to generate steam, reducing the power requirements of the heating module. The heater power is low, resulting in overall energy savings and a significant reduction in the load on the power board. Furthermore, it comprehensively judges the duration of contamination and matches the cleaning intensity accordingly, ensuring thorough cleaning while minimizing energy waste and avoiding energy waste and accelerated module lifespan damage caused by using the same strong cleaning mode. Steam generation uses dynamic intermittent parameter adjustment, autonomously adjusting steam generation parameters based on water temperature; or, by heating to a constant temperature via the heat pump, using constant parameters. This avoids problems such as insufficient steam generation or low steam purity, ensuring effective cleaning. Attached Figure Description

[0076] Figure 1 This is a schematic diagram of a range hood according to an embodiment of the present invention;

[0077] Figure 2 This is a schematic diagram of the pipe connection of a range hood according to an embodiment of the present invention;

[0078] Figure 3 This is a top view of a range hood according to an embodiment of the present invention;

[0079] Figure 4 This is a schematic diagram of the concealed air intake assembly, fan frame front cover, and part of the cleaning device of a range hood according to an embodiment of the present invention.

[0080] Figure 5 This is a schematic diagram of the concealed air intake assembly, fan frame front cover, and part of the cleaning device of a range hood according to an embodiment of the present invention (and...). Figure 4 (Different perspectives);

[0081] Figure 6 This is a schematic diagram of the fan system and part of the cleaning device of a range hood according to an embodiment of the present invention;

[0082] Figure 7 This is a flowchart (partial steps) of a self-cleaning control method for a range hood according to an embodiment of the present invention;

[0083] Figure 8 This is a flowchart of a self-cleaning control method for a range hood according to an embodiment of the present invention (partial steps, see below). Figure 7 )

[0084] Figure 9 This is a flowchart of a self-cleaning control method for a range hood according to an embodiment of the present invention (partial steps, see below). Figure 8 ). Detailed Implementation

[0085] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions.

[0086] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Since the embodiments disclosed in this invention can be arranged in different directions, these terms indicating direction are only for illustration and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0087] SeeFigures 1-6 A range hood includes a smoke collection hood 1, a fan frame 2 mounted on the smoke collection hood 1, a fan system 3 disposed within the fan frame 2, and a cleaning device for cleaning the fan system 3. The form in which the range hood draws air through the smoke collection hood 1 is not limited, and can adopt existing technologies such as side-suction or low-suction types. The fan system 3 is a centrifugal fan, including a volute 31 and an impeller 32 disposed within the volute 31.

[0088] The cleaning device includes a water system and a heat pump system. The water system can utilize existing technology and includes a water storage box 41, a heating module 42, a nozzle 43, a condensate box 44, a water pump 45, a heat exchanger 46, a first valve 471, and a second valve 472. The heat pump system includes an evaporator 51, a condenser 52, a compressor 53, a fan 54, two three-way valves 55, and an expansion valve 56. The specific structure and piping connection methods of the above devices will be detailed below.

[0089] A water storage box 41 can be installed inside the fume hood 1. It stores cleaning media and serves as the source of the cleaning media, such as water or cleaning agents. The following description uses water as an example. The water storage box 41 is equipped with an adapter 411 and an NTC 412. The water storage box 41 and the adapter 411 are connected via a suction nozzle (not shown, integrated with the water storage box 41) and a seal. An inlet pipe 48 and a return pipe 49 are connected to the adapter 411, both of which are in fluid communication with the inside of the water storage box 41. The NTC 412 can be located at the adapter 411 to detect the temperature of the water inside the water storage box 41. A water pump 45 can be located on the top outer side of the fan frame 2 to provide pressure. The water storage box 41 and the water pump 45 are connected via the inlet pipe 48, allowing the water pump 45 to pump water out of the water storage box 41. The water inlet pipe 48 originates from the water storage box 41, passes through the right-side space inside the smoke hood 1 (or the left-side space, but in this embodiment, the right-side space is used as an example), exits the smoke hood 1, and runs along the right-side pipe position on the outer right side of the fan frame 2 (the fan frame 2 is usually covered by a fan cover, so the water inlet pipe 48 will not be exposed at this location) until it reaches the top of the fan frame 2 and connects to the water pump 45. The outlet of the water pump 45 enters the fan frame 2 through the first water pipe 451, passes through the first through-hole 21 at the top of the fan frame 2, and then connects to the heat exchanger 46. The heat exchanger 46 can be a series of copper tubes arranged at equal intervals, sandwiched between condensers 52, and located at the bottom of the volute 31 of the fan system 3. This allows the condenser 52 to increase the heat exchange area of ​​the heat exchanger 46, thereby improving the heat exchange efficiency. The outlet of heat exchanger 46 is connected to the inlet of first valve 471 via second connecting water pipe 461. First valve 471 can be a two-position three-way solenoid valve. One outlet of its valve is connected to the inlet of heating module 42 via third connecting water pipe 4721, while the other outlet flows back to water storage box 41. It can also flow back through return water pipe 49, through second through-hole 22, to the right side of fan frame 2, and down along the right-hand path of inlet pipe 48 to connect to adapter 411, thus achieving the return to water storage box 41. The outlet of heating module 42 is connected to nozzle 43. The form of nozzle 43 is not limited; any structure capable of spraying cleaning media in the prior art can be used. In this embodiment, a moving nozzle 43 is preferred, such as the cleaning media supply component disclosed in Chinese Patent Application No. 202111284408.2.

[0090] The evaporator 51 and condensate box 44 are located inside the fume hood 1. The condensate box 44 is used to collect the condensate formed by the evaporator 51. A level sensor 441 can be installed on it to detect whether the water level is normal and whether there is any overflow. The outlet of the condensate box 44 is connected to the second valve 472 through a hose, so that the condensate is collected into the water storage box 41 through the second valve 472. In this embodiment, the evaporator 51 and condensate box 44 have two sets arranged symmetrically on the left and right. Therefore, the second valve 472 is a two-inlet and one-outlet on / off valve. The activation is determined by the level sensor 441 on each condensate box 44.

[0091] In the heat pump unit, two evaporators 51 are connected in parallel. The liquid inlets of the evaporators 51 are combined into one channel through a three-way valve 55 on one side (left side in this embodiment), and the liquid outlets are combined into one channel through a three-way valve 55 on the other side (right side in this embodiment). The three-way valves 55 are located on the bottom outer side of the fan frame 2. Therefore, the first pipe 571 connecting the evaporators 51 and the three-way valves 55 needs to extend out of the fume hood 1. The fan 54 is located on the left and right walls of the fume hood 1 and can draw in air from outside the fume hood 1 (the kitchen environment outside the range hood) and blow it towards the evaporators 51, thereby facilitating the evaporators 51 to absorb heat from the kitchen environment.

[0092] Compressor 53, used to compress refrigerant to form a high-temperature, high-pressure medium, is located on the top outer side of the fan frame 2. The outlet of the three-way valve 55 on the right side is connected to the inlet of compressor 53 via a second pipe 572, running upwards along the outer right side of the fan frame 2, passing the top of the fan frame 2. The outlet of compressor 53 is connected to a third pipe 573. This third pipe 573 is connected to the inlet of condenser 52 via a third through-hole 23 on the top of the fan frame 2, thereby allowing heat from compressor 53 to be transferred to condenser 52. The heat from condenser 52 is used to heat water, while the residual heat acts on the surface of the volute 31 of the fan system 3, achieving a certain degree of oil melting. Expansion valve 56 can be installed at the top inside the fan frame 2. The liquid outlet of condenser 52 is connected to the liquid inlet of one end of expansion valve 56 through a fourth pipe 574. The liquid outlet of the other end of expansion valve 56 is connected to a fifth pipe 575. This fifth pipe 575 extends from the fourth through-hole 24 on the left side of fan frame 2 to the outside of fan frame 2, and then runs down along the left-hand pipe position on the left side of fan frame 2 to connect with the interface of the left-hand tee 55, thereby connecting with the liquid inlet of evaporator 51, thus forming a circulation system. In this circulation system, expansion valve 56 is used to control the refrigerant flow rate, achieving the purpose of throttling and creating conditions for evaporation.

[0093] All water pipes used in the aforementioned water circuit are flexible hoses, while all pipes used in the heat pump unit (except for the pipe connecting the condensate box 41 and the water storage box 41) are copper pipes. By employing a heat pump unit, which operates only in one direction for heating, it utilizes air energy to fully utilize the hot air in the kitchen after meals. Since the heat pump unit achieves 3 to 4 times the heating effect with one unit of electricity, the overall power consumption is reduced, the load on the power board of the range hood's control module is lowered, and the energy-saving effect is good. Because the fan 54 of the heat pump unit applies the hot kitchen air to the evaporator 51, the evaporator 51 absorbs heat, thus lowering the kitchen temperature; the condenser 52 absorbs heat and produces condensate on its surface, absorbing and condensing moisture in the air, thereby reducing the humidity in the kitchen.

[0094] See Figures 7-9 The diagram illustrates the flow of the self-cleaning control method for the aforementioned range hood (due to the large number of steps, it cannot be clearly shown in one figure, so it is divided into three figures, with ports with the same number in each figure indicating connected steps), including the following steps:

[0095] 1) Start by activating the self-cleaning function;

[0096] 2) The heat pump device is running. After a certain delay, it is determined whether the delay is sufficient, such as 1 to 2 minutes. If not, this step is repeated. If the delay is sufficient, proceed to step 3). The main purpose of the delay in this step is to preheat the condenser 52 and allow it to reach the rated temperature first, so as to avoid inefficient heat exchange in the early stage and improve efficiency and energy saving.

[0097] 3) Then the water pump 45 runs, and water flows from the water storage box 41 through the water pump 45, through the heat exchanger 46 to exchange heat in the condenser 52, and then through the first valve 471. At this time, the first valve 471 does not operate, the right water path is connected, and the water is sent back to the water storage box 41 through the return water pipe 49.

[0098] 4) The NTC412 detects that the temperature of the water flowing back into the water storage box 41 is T, and determines whether T≥B1℃ is true, where B1 is a preset first temperature threshold, usually the temperature at which the water feels hot, preferably B1 is 50℃; if yes, proceed to step 4.1), if no, proceed to step 4.2):

[0099] 4.1) Read the continuous running time t and cumulative running time t0 of the range hood. These two durations can be obtained through the timer of the original control module of the range hood, which can be used to determine the degree of pollution of the range hood; then determine whether t≥t0 is true, where t0 is a preset threshold for the continuous running time that needs cleaning, preferably t0 is 480h. If yes, proceed to step 5); if no, then determine whether t0≥t00 is true, where t00 is a preset threshold for the cumulative running time that needs cleaning, preferably t00 is 30h. If yes, proceed to step 5); if no, proceed to step 6); In this step, the heat pump device prepares for heating. After completion, the continuous running time t and cumulative running time t0 are read to determine the degree of pollution. The continuous running time refers to the cumulative time since the last cleaning of the range hood, and the cumulative running time refers to the cumulative running time since the last cleaning. First, t is judged. If it is greater than a certain value, such as 20 days, the strong cleaning mode is directly matched. Otherwise, it is judged whether t0 is greater than a certain threshold, such as 30 hours. The threshold can be given according to the user's general usage habits. If it is greater than 30 hours, the strong cleaning mode is matched again. Otherwise, the weak cleaning mode is matched. In this way, the degree of pollution is identified and the cleaning intensity is automatically matched to avoid inadequate cleaning or energy waste caused by using the same mode for all cleaning.

[0100] 4.2) Judgment If the condition is met, return to step 3); otherwise, proceed to step 4.1. Where d is the heating efficiency threshold, such as 20%. This refers to the ratio of the final heating rate to the initial heating rate, used to determine... The purpose is to monitor heating efficiency changes in real time. When the ambient temperature is low, the heating efficiency gradually decreases due to the rapid rate of heat loss. When the efficiency drops below a certain threshold, such as 20%, heating water becomes difficult, and continuing to heat will waste energy. Therefore, this conditional limitation achieves energy saving and adapts to the ambient temperature. The temperature is monitored in real time, but frequent monitoring is not necessary; monitoring once every 30-60 seconds is sufficient. The numerator represents the temperature difference between two adjacent values ​​at the end of the period, and the denominator represents the temperature difference between two adjacent values ​​at the beginning of the period. T i T refers to the temperature detected for the i-th time. i-1 T0 refers to the temperature detected in the previous (i-1th) instance. T0 is the initial temperature detected after the heat pump has been running stably, which is close to the water temperature added to the water storage box 41. T1 is the temperature detected for the first time thereafter.

[0101] 5) Enter steam cleaning mode, also known as intensive cleaning mode, which uses a combination of steam and hot water:

[0102] 5.1) The heat pump device is turned off. The NTC412 detects and records the current temperature T. At this time, the heat pump device cannot supply heat to generate steam. A low-power heating module 42 is required. The heat pump device is turned off because the water temperature is not lower than B1. If the heat pump device is turned on again, it will not be able to heat the water. Turning it off is also to save energy and reduce the load on the power board, and to avoid increasing the load when the heating module 42 is running at the same time. The temperature T here is the water temperature of the water storage box 41.

[0103] 5.2) The blower system 3 operates at the first speed (low speed) in order to further control the stability of the steam and adapt to different temperatures. Usually, the speed of the motor driving the impeller 32 of the blower system 3 is 30 to 60 r / min at this time.

[0104] 5.3) The first valve 471 is activated, which connects the first valve 471 and the heating module 42, while disconnecting the first valve 471 and the water storage box 41. Thus, the cleaning pipeline is connected, and the water does not pass through the return water pipe 49, but passes through the heating module 42 to the nozzle 43 to achieve cleaning. At this time, the water pump 45 is running.

[0105] 5.4) After a delay of a seconds, the water pump 45 stops running, where a is the preset running time of the water pump 45 during cleaning. This allows the heating module 42 to be filled with water, preventing dry burning later. After it is filled, the water pump 45 stops running.

[0106] 5.5) The heating module 42 operates until it heats to the preset second threshold B2℃, at which point the water can be converted into steam, B2 > B1. Since the water entering the heating module 42 has already been heated, the temperature rise required for further heating to produce steam is small, requiring only a small power. This is at least half the power of using the heating module alone. If only 1200W of heating is needed, only about 700W is required after adding the heat pump, thereby reducing the load on the power board. The temperature detected here is the temperature W detected by the temperature sensor built into the heating module 42. This temperature represents the value when the heating module 42 produces the target steam and stabilizes. The temperature varies depending on the heating module 42, and B2 is generally above 100℃ and below 135℃.

[0107] 5.6) The nozzle 43 sprays steam to clean the fan system 3. In this embodiment, the stepper motor that drives the nozzle 43 starts to run in a reciprocating cycle, which, together with the rotation of the impeller 32, achieves a thorough cleaning.

[0108] 5.7) The water pump 45 operates in a reciprocating cycle, running for b seconds and stopping for c seconds, repeating this process. Since the heating module 42 does not directly heat the water to steam during cleaning, the water pump 45 operates intermittently. Parameter b is related to the flow rate of the water pump 45. The heating module 42 is refilled within time b without water overflowing through the nozzle 43. Once time b is determined, the running time c determines the purity and steam impact intensity of the steam. To generate continuous steam and maintain a certain level of steam purity, preferably, the relationship between the stopping time c and the running time b satisfies the following relationship:

[0109]

[0110] In the above, Q is the actual flow rate of the water pump 45 installed in the entire water circuit device, in g / s; P is the power of the heating module, in W; η is the efficiency of the heating module 42; T is the water temperature of the water storage box 41; b is known; before steam generation, c can be determined after detecting the temperature T; the program assigns the c value for this cleaning; therefore, it can adapt to different water temperatures, ensure steam stability, and guarantee the impact strength; this is the preferred choice. If it can be ensured that the water temperature after system heating is constant, a fixed c value can be used, which can also be calculated by the formula.

[0111] 5.8) Run the steam mode for the preset time, and then proceed to step 7); for example, when the steam mode has run for 2 cycles, that is, the nozzle 43 has reciprocated for 2 cycles, the steam mode ends and the subsequent hot water cleaning begins.

[0112] 6) Enter the hot water washing mode, also known as the gentle wash mode:

[0113] 6.1) The heat pump device is turned off. The NTC412 detects and records the current temperature T and determines whether T≥B1℃ is true. If yes, proceed to step 6.2). If no, the heating module 42 is started until T≥B1℃ is true, then proceed to step 6.2). The heating module 42 is mainly used to generate steam. During hot water cleaning, the heating requirement is not large.

[0114] 6.2) The fan system 3 operates at the first speed;

[0115] 6.3) The first valve 471 is activated, which connects the first valve 471 and the heating module 42, while disconnecting the first valve 471 from the water storage box 41, thereby connecting the cleaning pipeline.

[0116] 6.4) After a delay of a seconds, nozzle 43 sprays hot water to clean the fan system 3. In this embodiment, the stepper motor that drives nozzle 43 starts reciprocating cycle operation, and proceeds to step 7).

[0117] 7) The water pump 45 runs continuously; the hot water in the water storage box 41 is further heated by the heating module 42 to produce hotter water, which cleans and flushes the impeller 32.

[0118] 8) Determine whether the current I of water pump 45 is true or false, where C is the preset operating current threshold of water pump 45; if yes, it means that the water is used up and proceed to step 9); if no, return to step 7).

[0119] 9) Heating module 42 stops running, water pump 45 stops running, and the stepper motor driving nozzle 43 returns to zero;

[0120] 10) The first valve 471 is de-energized and reset, the second valve 42 is disconnected from the heating module 42, and connected to the normal state circulating water circuit, that is, reconnected to the water storage box 41;

[0121] 11) The liquid level sensors 441 of the two condensate boxes 44 detect the current liquid levels Q1 and Q2 respectively; determine whether either Q1 or Q2 is 1. If yes, proceed to step 12); if no, proceed to step 17). After the cleaning process is completed, it is necessary to determine whether the condensate is full and to clean the volute 31 regularly. If either Q1 or Q2 is 1, it means that the condensate box 44 is full. If both Q1 and Q2 are 0, it means that the water box is not full and the water volume is insufficient. The volute 31 cleaning procedure is not required, and the process can be skipped directly to the impeller 32 spin-drying stage.

[0122] 12) The second valve 472 is activated, which connects the condensate box 44 and the water storage box 41, and the water from the two condensate boxes 44 converges into the water storage box 41.

[0123] 13) Determine if either Q1 or Q2 is 0. If yes, proceed to step 14); otherwise, return to step 12.

[0124] 14) When either Q1 or Q2 is detected to be 0, it indicates that the water in the condensate box 44 has been completely released, and the cleaning of the fan system 3 begins, mainly focusing on the cleaning of the volute 31:

[0125] 14.1) When the second valve 472 is de-energized and closed, the connection between the condensate box 44 and the water storage box 41 is broken, and the heat pump unit starts operating;

[0126] 14.2) Start water pump 45 to make it run, and then determine whether the return water temperature T≥B1℃ is true (through continuous circulation and heat exchange, the water temperature rises until it becomes hot water). If yes, proceed to step 14.3); if no, then determine... If the condition is met, proceed to step 14.3; otherwise, repeat this step.

[0127] 14.3) The heat pump device is turned off, the heating module 42 is running, and the fan system 3 is running at the second speed (high speed). The purpose of the condensate is to clean the volute 31. The cleaning of the volute 31 is achieved by the high-speed rotation of the impeller 32 of the fan system 3 driving the hot water jet to act on the annular wall of the volute 31. The high-speed rotation here is about 300 to 500 r / min, which is higher than the speed of the cleaning impeller 32, but lower than the speed of the impeller 32 throwing water.

[0128] 14.4) During cleaning, the first valve 471 is activated, which connects the first valve 471 and the heating module 42, while disconnecting the first valve 471 from the water storage box 41, thereby connecting the cleaning pipeline.

[0129] 14.5) The nozzle 43 sprays hot water to clean the fan system 3. In this embodiment, the stepper motor that drives the nozzle 43 starts reciprocating cycle to ensure that the volute 31 and impeller 32 on the entire axial direction can be cleaned.

[0130] 14.6) Water pump 45 continues to operate. The water heated by the heat pump unit is reheated by heating module 42 and acts on impeller 32. Since the jet directly acts on the concave surface (pressure surface) of the impeller 32 blades, the water is thrown onto the annular wall surface of volute 31 by centrifugal force when impeller 32 rotates at high speed, cleaning volute 31. Since the oil accumulation is in the lower part of volute 31, the overflow heat from the heat pump unit while heating the hot water will heat the lower half of volute 31, softening it to a certain extent. Then, under the impact and scouring action of hot water, volute 31 is cleaned. Because it is a combination of softening + hot water impact, scouring + high-speed water throwing by the impeller, daily cleaning of the heat pump... The condenser 52 of the device also softens the oil stains on the volute 31 when it dissipates heat. Under the action of hot water, there will still be a certain cleaning effect. However, the impeller 32 rotates at a low speed, so the cleaning effect is not good. At this time, the main object to be cleaned is the impeller 32. A small amount of oil accumulation on the volute 31 has little impact on performance, and the daily cleaning of the impeller can also take care of the volute 31. Therefore, the volute 31 does not need to be cleaned frequently. The condensate needs to be cleaned many times to fill up. It is just right to clean the volute 31 regularly. This not only handles the condensate and prevents it from flowing back to the oil cup 6 (similar to the setting of the water storage box 41), avoiding the user from cleaning the oil cup 6 frequently, but also uses the condensate to clean the volute 31 regularly, avoiding the odor from affecting the kitchen environment.

[0131] 14.7) During operation, it is also necessary to identify whether the water pump 45 is without water, that is, to determine whether the current I ≤ C of the water pump 45 is true. If yes, proceed to step 15) and end the cleaning of the volute 31. If no, return to step 14.6).

[0132] 15) Heating module 42 stops running, water pump 45 stops running, and stepper motor returns to zero;

[0133] 16) The first valve 471 is de-energized and reset, the second valve 42 is disconnected from the heating module 42, and connected to the normal state circulating water circuit, that is, reconnected to the water storage box 41;

[0134] 17) The fan system 3 runs at the third speed (high speed) for a preset time to spin dry, such as 3 minutes, and then proceeds to step 18); the third speed is greater than the second speed;

[0135] 18) Turn off self-cleaning mode, set the cumulative runtime t0 and continuous runtime t to zero, and end.

[0136] In the control method described above in this invention, the purpose of producing steam or hot water at a specific temperature is achieved. Under the same configuration, if the heat pump device and the heating module 42 are turned on simultaneously to directly spray water, the water temperature cannot even reach 50°C because the overall power is insufficient. When heating separately, the heat pump device first preheats the water temperature through the circulation system to raise it above 50°C. The heat pump device is energy-efficient and more energy-efficient than the heating module 42 under the same conditions. Subsequently, the heating module 42 is selected based on the cleaning intensity to determine whether to heat and generate steam. In this way, the power of the heating module 42 is selected very low, which can also ensure the generation of steam. At the same time, compared with directly generating steam, the original water temperature is also raised from room temperature to 50°C. The heating module 42 not only selects a low power but is also energy-efficient because part of the temperature rise of the heating module 42 is transferred to the energy-saving heat pump.

Claims

1. A range hood, comprising a fan system (3) and a cleaning device for cleaning the fan system (3), the cleaning device comprising a water circuit device, the water circuit device comprising a heating module (42) for heating a cleaning medium and a nozzle (43) for spraying the cleaning medium flowing out of the heating module (42) onto the fan system (3) for cleaning; characterized in that: The water circuit device also includes a heat exchanger (46), which is located upstream of the heating module (42) in the flow path of the cleaning medium. The cleaning device also includes a heat pump device, which includes an evaporator (51), a condenser (52) and a compressor (53) forming a loop, wherein the condenser (52) is used to provide a heat source to the heat exchanger (46); The water circuit device also includes a water storage box (41) for storing cleaning medium and a water pump (45). The water storage box (41) and the water pump (45) are connected by an inlet pipe (48). The outlet of the water pump (45) is connected to a heat exchanger (46) through a first water pipe (451). A return water pipe (49) is also connected between the heat exchanger (46) and the water storage box (41). The heat exchanger (46) is selectively connected to the heating module (42) and the water storage box (41) respectively. The water circuit device also includes a first valve (471). The outlet of the heat exchanger (46) is connected to the inlet of the first valve (471) through a second connecting water pipe (461). One outlet of the first valve (471) is connected to the inlet of the heating module (42) through a third connecting water pipe (4721), and the other outlet is connected to the water storage box (41) through a return water pipe (49). This allows the heat exchanger (46) to be selectively connected to the heating module (42) and the water storage box (41) respectively.

2. The range hood according to claim 1, characterized in that: The heat exchanger (46) consists of copper tubes arranged in a circulating pattern and sandwiched between the condenser (52).

3. The range hood according to claim 2, characterized in that: The fan system (3) includes a volute (31) and an impeller (32), and the condenser (52) is located at the bottom of the volute (31).

4. The range hood according to claim 1, characterized in that: The water circuit device also includes a condensate box (44) for collecting condensate formed by the evaporator (51), and the outlet of the condensate box (44) is connected to the water storage box (41).

5. The range hood according to claim 4, characterized in that: The water circuit device also includes a second valve (472) disposed between the condensate box (44) and the water storage box (41), which allows the condensate box (44) and the water storage box (41) to be connected or disconnected.

6. The range hood according to claim 1, characterized in that: The heat pump device also includes a fan (54) for drawing in air from outside the range hood and blowing it toward the evaporator (51).

7. The range hood according to claim 1, characterized in that: The heat pump device also includes an expansion valve (56), the liquid outlet of the condenser (52) is connected to the liquid inlet of the expansion valve (56), and the liquid outlet of the expansion valve (56) is connected to the liquid inlet of the evaporator (51).

8. A self-cleaning control method for a range hood as described in claim 1, comprising the following steps: 1) Start by activating the self-cleaning function of the range hood; 2) The heat pump unit is operating; 3) When the water pump (45) is running, the heat exchanger (46) and the water storage box (41) are connected. The cleaning medium is pumped from the water storage box (41) through the water pump (45), passes through the heat exchanger (46) to exchange heat in the condenser (52), and then sends the cleaning medium back to the water storage box (41) through the return water pipe (49). 4) Detect the temperature T of the cleaning medium flowing back into the water storage box (41), and determine whether T≥B1℃ is true, where B1 is a preset first temperature threshold. If yes, proceed to step 4.1); otherwise, proceed to step 4.

2. 4.1) Read the continuous running time t and cumulative running time t0 of the range hood, and then determine whether t≥t0 is true, where t0 is the preset threshold of continuous running time that needs to be cleaned. If yes, proceed to step 5); if no, then determine whether t0≥t00 is true, where t00 is the preset threshold of cumulative running time that needs to be cleaned. If yes, proceed to step 5); if no, proceed to step 6. The continuous running time refers to the cumulative value of the running time of the range hood since the last cleaning, and the cumulative running time refers to the cumulative value of the running time of the range hood since the last cleaning. 4.2) Determine if heating efficiency is required. If not, return to step 3). If yes, proceed to step 4.1). 5) Enter steam cleaning mode. At this time, the heat pump device is turned off. The cleaning medium is heated into steam through the heating module (42). After the steam cleaning operation has been running for a preset time, proceed to step 7). 6) Enter the hot cleaning medium cleaning mode. At this time, the heat pump device is turned off. The cleaning medium is heated to the temperature B1℃ required for liquid cleaning by the heating module (42). After running for a preset time, proceed to step 7). 7) The water pump (45) operates continuously, and cleaning is performed through the heating module (42) and the nozzle (43); 8) Determine whether the cleaning medium in the water pump (45) has been used up. If it has been used up, stop running. If it has not been used up, return to step 7.

9. The self-cleaning control method for a range hood according to claim 8, characterized in that: In step 2), the heat pump device operates, and after a certain delay, it proceeds to step 3).

10. The self-cleaning control method for a range hood according to claim 8, characterized in that: The fan system (3) includes an impeller (32). In step 5), the steam cleaning target is the impeller (32), and includes the following steps: 5.1) The heat pump device is turned off, and the temperature T of the cleaning medium in the water storage box (41) is detected and recorded; 5.2) The fan system (3) operates at a first speed; 5.3) This connects the heat exchanger (46) and the heating module (42), while disconnecting the heat exchanger (46) and the water storage box (41); 5.4) After a delay of a seconds, the water pump (45) stops running; 5.5) The heating module (42) operates until it is heated to the preset second threshold B2℃, B2>B1, so that the cleaning medium is heated into steam; 5.6) The nozzle (43) sprays steam to clean the fan system (3); 5.7) The water pump (45) operates in a reciprocating cycle; 5.8) Run the steam mode for the preset time, then proceed to step 7).

11. The self-cleaning control method for a range hood according to claim 10, characterized in that: In step 5.7), the water pump (45) operates in a cycle of b seconds, stops for c seconds, and repeats this cycle. b is a parameter related to the flow rate of the water pump (45). During time b, the cleaning medium fills the heating module (42) without passing through the nozzle (43), and satisfies the following relationship: Q is the actual flow rate of the water pump (45) installed in the entire water circuit device, P is the power of the heating module, η is the heating module (42), and T is the temperature of the cleaning medium in the water storage box (41).

12. The self-cleaning control method for a range hood according to claim 8, characterized in that: The fan system (3) includes an impeller (32). In step 6), the object to be cleaned is the impeller (32), and the cleaning process includes the following steps: 6.1) The heat pump device is turned off, the temperature T of the cleaning medium in the water storage box (41) is detected and recorded, and it is determined whether T≥B1℃ is true. If yes, proceed to step 6.2). If no, the heating module (42) is started until T≥B1℃ is true, and then proceed to step 6.2). 6.2) The fan system (3) operates at a first speed; 6.3) This connects the heat exchanger (46) and the heating module (42), while disconnecting the heat exchanger (46) and the water storage box (41); 6.4) The nozzle (43) sprays cleaning medium to clean the fan system (3).

13. The self-cleaning control method for a range hood according to claim 8, characterized in that: The fan system (3) includes a volute (31) and an impeller (32) disposed inside the volute (31). The cleaning object in steps 5) and 6) is the impeller (32). The water circuit device also includes a condensate box (44) for collecting condensate formed by the evaporator (51). The outlet of the condensate box (44) is connected to the water storage box (41). Step 8) is followed by the following steps: 9) The heating module (42) stops operating, and the water pump (45) stops operating; 10) The heat exchanger (46) is disconnected from the heating module (42) but connected to the water storage box (41); 11) Determine whether the cleaning medium in the condensate box (44) is full. If yes, clean the volute (31). If no, spin dry the impeller (32).

14. The self-cleaning control method for a range hood according to claim 13, characterized in that: In step 11), if so, proceed to step 12) to make the condensate box (44) and the water storage box (41) connected; 13) Determine whether the cleaning medium in the condensate box (44) has been completely released. If yes, proceed to step 14); otherwise, return to step 12. 14) Begin cleaning the volute (31): 14.1) This disconnects the condensate box (44) and the water storage box (41), allowing the heat pump to operate; 14.2) Start the water pump (45) and then determine whether the temperature of the cleaning medium returning to the water storage box (41) is T≥B1℃. If yes, proceed to step 14.3). If no, determine whether the heating efficiency meets the requirements. If yes, proceed to step 14.3). If no, repeat this step. 14.3) The heat pump device is turned off, the heating module (42) is running, and the fan system (3) is running at a second speed, which is greater than the first speed; 14.4) During cleaning, the heat exchanger (46) and the heating module (42) are connected but disconnected from the water storage box (41); 14.5) The nozzle (43) sprays cleaning medium to clean the volute (31); 14.6) The water pump (45) continues to operate, and the cleaning medium heated by the heat pump device is reheated by the heating module (42); 14.7) Determine whether the cleaning medium in the water pump (45) has been used up. If yes, end the cleaning of the volute (31). If no, return to step 14.

6.

15. The self-cleaning control method for a range hood according to claim 14, characterized in that: After determining in step 14.7) that the cleaning medium in the water pump (45) has been used up, proceed to step 15), the heating module (42) stops running, the water pump (45) stops running, and the cleaning of the volute (31) ends; 16) The heat exchanger (46) is disconnected from the heating module (42) and reconnected to the water storage box (41) to reset; 17) The fan system (3) uses a third rotational speed to spin-dry the impeller (32), which is greater than the second rotational speed; 18) Turn off self-cleaning mode, set the cumulative runtime t0 and continuous runtime t to zero, and end.

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