Defrosting structure and refrigerator

Abstract

The utility model provides a defrosting structure and a refrigerator, and the defrosting structure comprises a heat exchange pipeline which is used for circulating fluid; the heat exchange fins are connected with the heat exchange pipeline; the electrifying device is connected with the heat exchange fins to electrify the heat exchange fins, so that the heat exchange fins generate heat; and the control module is used for adjusting the power of the energizing device for energizing the current according to the temperature of the frost on the defrosting structure. The defrosting structure solves the technical problem that the defrosting efficiency of a heat exchanger is low in the prior art.

Description

Technical Field

[0001] The utility model relates to the technical field of defrosting, in particular to a defrosting structure and a refrigerator. Background Art

[0002] The existing methods for defrosting an evaporator are as follows:

[0003] 1. On the basis of arranging a defrosting heater at the bottom of the evaporator, an additional graphene heating film is set at the top of the evaporator to improve the defrosting efficiency of the top of the evaporator, shorten the defrosting time of the refrigerator, and ensure the refrigeration effect of the refrigerator. However, although this method solves the problem of slow defrosting speed (too long defrosting time) at the top of the evaporator, there is no effective control measure for suppressing the overflow of hot air into the freezer compartment.

[0004] 2. A spraying device is set to spray condensed water and defrosting water onto the air outlet and the air return opening before defrosting to prevent the hot air from overflowing into the freezer compartment during defrosting and causing a rapid temperature rise. However, although this method solves the problem of hot air overflow, it is difficult to transport, spray, form and eliminate the ice film of condensed water and defrosting water at a low temperature, and an additional heating device is required to assist, resulting in additional heat release, and there is a possibility that the circulating water pollutes other items.

[0005] 3. A permanent magnet fan blade is installed on the shaft of the axial flow fan to act as a magnetic field source, and a freely openable and closable coil is arranged around the heat exchanger. When the external heat exchanger needs to be defrosted, the coil is closed, and the magnetic field of the fan blade cuts the coil to generate current to melt the ice and frost. However, the motional electromotive force has high requirements for the magnetic field density. When the air gap width between the fan blade and the closed coil is not small enough, the magnetic induction intensity in the coil will be greatly weakened, and it is difficult to improve the defrosting power.

[0006] Therefore, the existing technology still has the problem of low defrosting efficiency of the heat exchanger. Summary of the Utility Model

[0007] The purpose of the utility model is to overcome the above technical deficiencies and provide a defrosting structure and a refrigerator to solve the technical problem of low defrosting efficiency of the heat exchanger in the related technology.

[0008] To achieve the above technical purpose, the utility model adopts the following technical solutions: A defrosting structure is provided, including: a heat exchange pipeline for circulating a fluid therein; heat exchange fins connected to the heat exchange pipeline; an energizing device connected to the heat exchange fins to energize the heat exchange fins so that the heat exchange fins generate heat; and a control module that adjusts the power of the current passed through the energizing device according to the temperature of the ice and frost on the defrosting structure.

[0009] Further, connection holes are provided on the heat exchange fins, and the heat exchange fins are inserted into the connection holes.

[0010] Furthermore, there are multiple heat exchange pipelines, which are arranged at intervals; there are multiple connection holes, and the multiple connection holes are arranged in one-to-one correspondence with the multiple heat exchange pipelines.

[0011] Furthermore, there are multiple heat exchange fins, which are arranged at intervals.

[0012] Furthermore, there are multiple heat exchange fins, which are arranged at intervals; the defrosting structure includes a connecting piece, one end of the connecting piece is connected to one of two adjacent heat exchange fins, and the other end of the connecting piece is connected to the other of the two adjacent heat exchange fins; wherein, the multiple heat exchange fins are arranged along a preset direction, and the energizing device is respectively connected to two heat exchange fins located at both ends of the multiple heat exchange fins.

[0013] Furthermore, multiple connecting pieces are arranged between two adjacent heat exchange fins; the multiple connecting pieces between two adjacent heat exchange fins are arranged at intervals to form a heat dissipation groove between two adjacent connecting pieces; the heat dissipation groove communicates with the gap between two adjacent heat exchange fins.

[0014] Furthermore, there are multiple heat exchange fins, which are arranged at intervals; there are multiple energizing devices, and the multiple energizing devices are connected to the multiple heat exchange fins in one-to-one correspondence.

[0015] Furthermore, the defrosting structure further includes an insulating component, the insulating component is sleeved on the heat exchange pipeline, an insulating groove is arranged on the insulating component, and the insulating component is embedded on the heat exchange fin through the insulating groove.

[0016] Furthermore, the defrosting structure further includes: a temperature sensor, the temperature sensor is connected to the heat exchange fin; the temperature sensor is signal-connected to the control module, and the control module adjusts the power of the current passed through the energizing device according to the temperature value detected by the temperature sensor.

[0017] A refrigerator includes a defrosting structure, and the defrosting structure is the above-mentioned defrosting structure.

[0018] Beneficial effects:

[0019] 1. The defrosting structure of the present utility model uses a low-voltage DC device to directly heat the aluminum evaporator, and can melt the ice and frost attached to the evaporator fins from the inside out;

[0020] 2. The control method of the present utility model adopts a method of dividing the temperature zone to regulate the input power of defrosting the evaporator, and adapts the defrosting input power at each temperature point by collecting the temperature of the sensor outside the evaporator. Description of the drawings

[0021] Figure 1 It is a schematic structural diagram of the defrosting structure adopted in the embodiment of the present utility model;

[0022] Figure 2 is the front view of the defrosting structure adopted in the embodiment of the present utility model;

[0023] Figure 3 is the schematic structural diagram of the heat exchange pipeline of the defrosting structure adopted in the embodiment of the present utility model;

[0024] Figure 4 is the schematic structural diagram of the insulating component of the defrosting structure adopted in the embodiment of the present utility model;

[0025] Figure 5 is the top view of the insulating component of the defrosting structure provided by the embodiment of the present utility model;

[0026] Figure 6 is the curve graph of the change relationship between the ice and frost heat and temperature provided by the embodiment of the present utility model;

[0027] Figure 7 is the curve graph of the change relationship between the temperature of the ice and frost and the power of the defrosting structure provided by the embodiment of the present utility model.

[0028] Among them, the above-mentioned drawings include the following reference numerals:

[0029] 1. Heat exchange pipeline; 2. Heat exchange fins; 21. Connection holes; 22. Connection pieces; 3. Insulating component; 31. Insulating grooves. Detailed implementation manners

[0030] In order to enable those skilled in the art of the present technology to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0031] See Figures 1 to 7 , according to the embodiment of the present utility model, a defrosting structure is provided, including: a heat exchange pipeline 1 for circulating a fluid therein; heat exchange fins 2 connected to the heat exchange pipeline 1; an energizing device connected to the heat exchange fins 2 to energize the heat exchange fins 2 so that the heat exchange fins 2 generate heat; a control module that adjusts the power of the current passed through the energizing device according to the temperature of the ice and frost on the defrosting structure. With the above settings, a low-voltage DC device is directly used to heat the aluminum evaporator, which can melt the ice and frost attached to the evaporator fins from the inside out, solving the technical problem of low defrosting efficiency of the heat exchanger in the related technology.

[0032] It should be noted that in this embodiment, the frost exists in solid state, as well as in liquid or even gaseous state after the frost melts, and the temperature of the frost includes the temperatures in different states of the frost.

[0033] In the defrosting structure of this embodiment, refer to Figure 1 、 Figure 2 , a connecting hole 21 is provided on the heat exchange fin 2, and the heat exchange fin 2 is inserted into the connecting hole 21. In this way, the heat exchange pipeline 1 can be arranged in the middle position of the heat exchange fin 2, effectively improving the defrosting efficiency.

[0034] In the defrosting structure of this embodiment, there are multiple heat exchange pipelines 1, and the multiple heat exchange pipelines 1 are arranged at intervals; there are multiple connecting holes 21, and the multiple connecting holes 21 are arranged in one-to-one correspondence with the multiple heat exchange pipelines 1.

[0035] In the defrosting structure of this embodiment, there are multiple heat exchange fins 2, and the multiple heat exchange fins 2 are arranged at intervals.

[0036] In this way, the heat exchange area can be increased, effectively improving the defrosting efficiency.

[0037] Refer to Figure 1 、 Figure 2 , in the defrosting structure of this embodiment, there are multiple heat exchange fins 2, and the multiple heat exchange fins 2 are arranged at intervals; the defrosting structure includes a connecting piece 22, one end of the connecting piece 22 is connected to one of the two adjacent heat exchange fins 2, and the other end of the connecting piece 22 is connected to the other of the two adjacent heat exchange fins 2; wherein, the multiple heat exchange fins 2 are arranged along a preset direction, and the energizing device is respectively connected to the two heat exchange fins 2 located at both ends of the multiple heat exchange fins 2.

[0038] Refer to Figure 1 , in the defrosting structure of this embodiment, multiple connecting pieces 22 are arranged between two adjacent heat exchange fins 2; the multiple connecting pieces 22 between two adjacent heat exchange fins 2 are arranged at intervals to form a heat dissipation groove 23 between two adjacent connecting pieces 22; the heat dissipation groove 23 communicates with the gap between two adjacent heat exchange fins 2. In this way, the air flow in the gap between two adjacent heat exchange fins 2 can flow out from the heat dissipation groove 23, thus ensuring the heat dissipation efficiency.

[0039] Specifically, in order to ensure electrical connection between each heat exchange fin 2, a connecting piece 22 is arranged between the multiple heat exchange fins 2, so that the multiple heat exchange fins 2 are connected in series.

[0040] In the defrosting structure of this embodiment, refer to Figure 1 、 Figure 2There are multiple heat exchange fins 2, and the multiple heat exchange fins 2 are arranged at intervals; there are multiple power-on devices, and the multiple power-on devices are connected to the multiple heat exchange fins 2 in a one-to-one correspondence.

[0041] With the above arrangement, the series connection of the heat sink fins 2 is changed to a parallel connection, and each heat sink fin 2 is independently controlled; the electrical wiring becomes very complicated, but the effect of independent control is better, and the failure of a local fin will not affect the overall effect too much.

[0042] See also Figure 4 , Figure 5 In the defrost structure of the present embodiment, the defrost structure further includes an insulating component 3, which is sleeved on the heat exchange pipeline 1, and an insulating groove 31 is provided on the insulating component 3. The insulating component 3 is embedded in the heat exchange fin 2 through the insulating groove 31.

[0043] Since the DC power supply is directly connected to the heat exchange fin 2, it is necessary to do a good job of insulation between the heat exchange fin 2 and other parts of the refrigerator. Usually, the heat exchange fin 2 is placed behind the back plate of the freezer compartment, and the traditional evaporator heat exchange pipeline 1 is directly connected to the heat exchange fin 2. The above arrangement ensures that the heat exchange pipeline 1 and the heat exchange fin 2 are firmly connected while also ensuring insulation. The insulating component 3 is made of insulating material.

[0044] In the defrost structure of this embodiment, the defrost structure also includes: a temperature sensor, the temperature sensor is connected to the heat exchange fin 2; the temperature sensor is connected to the control module signal, and the control module adjusts the power of the current passed into the power supply device according to the temperature value detected by the temperature sensor.

[0045] Specifically, since most of the frost will condense on the heat exchange fins 2, by arranging a temperature sensor on the heat exchange fins 2, the temperature of the frost can be detected, thereby making the temperature detection easier.

[0046] The refrigerator of this embodiment includes a defrost structure, and the defrost structure is the above-mentioned defrost structure.

[0047] The defrosting structure of the utility model is described as follows:

[0048] The traditional evaporator consists of a refrigerant pipe and fins. The refrigerant pipe passes through the cut and punched fins to form a complete evaporator. In order to ensure the heat transfer effect, the fins and the pipes maintain good contact.

[0049] In the defrosting structure of this embodiment, the aluminum fins are not cut during production. The complete long aluminum coil is punched and bent into the evaporator to ensure that the heat exchange fins 2 are electrically connected. When the evaporator needs to be defrosted, low-voltage direct current is passed to both ends of the heat exchange fins 2. The heat exchange fins 2 are structured as shown in FIG. Figure 1 shown.

[0050] Since a DC power supply is directly connected to the heat exchange fin 2, it is necessary to insulate the heat exchange fin 2 from other components of the refrigerator. Generally, the heat exchange fin 2 is placed behind the back panel of the freezer, and the traditional evaporator heat exchange pipeline 1 is directly connected to the heat exchange fin 2. Therefore, the heat exchange fin 2 of this embodiment needs to maintain high-efficiency heat transfer, high insulation, and stable properties with the heat exchange pipeline 1. The current solution is to put a thermal silicone pad (i.e., the insulating component 3) in the punched holes of the evaporator. The heat conduction and insulation effects are acceptable. Thermal silicone pads have been widely used in voltage regulators and radiators, CPUs and radiators, and will not directly explode like glass and ceramics in a transient environment.

[0051] When the refrigerator meets the defrosting condition and enters the defrosting process, a low-voltage direct current needs to be applied to the heat exchange fin 2. The parameters of the applied direct current are power P, voltage U, and current I respectively. To ensure safety, the DC voltage U generally does not exceed 24V. The input power P = basic power Pb + compensation power Pc.

[0052] See Figure 6 , set the maximum defrosting time Tmax = 40 min, where the ice temperature rising time T0 = 15 min, the ice phase change time T1 = 20 min, and the dripping time T2 = 5 min. It is known that the specific heat capacity of aluminum is 0.88 KJ / (Kg·℃), the specific heat capacity of ice is 2.1 KJ / (Kg·℃), the specific heat capacity of water is 4.2 KJ / (Kg·℃), the specific heat capacity of air is 1.40 KJ / (Kg·℃), the specific latent heat of ice melting into water is 355 KJ / Kg, and the air density is 1.41 kg / m3. The mass of the evaporator of a common refrigerator is generally between 1 and 3 Kg, and the refrigerator volume is positively correlated with the evaporator mass. Taking a 456L refrigerator of a certain brand as an example, the freezer volume is about 170L. During the defrosting period of a conventional steel pipe heater, the temperature in the freezer will rise by about 10 - 15℃. The heat Q0 approximately required for 170L of air to rise by 15℃ is Q0 = 0.17 * 1.41 * 15 * 1.40 = 5.0 KJ. For a 2Kg evaporator to rise from -26℃ to 0℃, the heat Q1 required to be absorbed is Q1 = 0.88 * 2 * 26 = 45.76 KJ. The mass of the ice on the evaporator is generally between 0.2 and 0.6 Kg. Taking the middle value of 0.4 Kg, the heat Q2 required for 0.4Kg of ice to rise from -26℃ to 0℃ is Q2 = 2.1 * 0.4 * 26 = 21.84 KJ. The reference input power Pb1 = (Q0 * T0 / Tmax + Q1 + Q2) / T0 = (5.0 * 15 / 40 + 45.76 + 21.84) * 1000 / 15 / 60 ≈ 77W.

[0053] The heat Q3 required for 0.4 Kg of ice at 0 °C to melt into water is Q3 = 355 * 0.4 = 142 KJ. Ignoring the case of the ice temperature rising back, the reference input power Pb2 = (Q0 * T1 / Tmax + Q2) / T1 = (5 * 20 / 40 + 142) * 1000 / 20 / 60 ≈ 120 W.

[0054] After the ice melts into water, the temperature begins to rise again. In this stage, the temperature of the evaporator heat exchange fin 2 is maintained at around 12 °C.

[0055] The heat Q4 required for 0.4 Kg of water at 0 °C to rise to 5 °C is Q4 = 4.2 * 0.4 * 5 = 8.4 KJ. The heat Q5 absorbed by the temperature rise of the evaporator heat exchange fin 2 is Q5 = 0.88 * 2 * 12 = 21.12 KJ. The reference input power Pb3 = (Q0 * T2 / Tmax + Q4 + Q5) / T2 = (5.0 * 5 / 40 + 8.4 + 21.12) * 1000 / 5 / 60 ≈ 100.5 W.

[0056] Based on the above theoretical calculations, the basic input power of the heat exchange fin 2 is as Figure 7 shown.

[0057] The basic input power is a data analysis based on a certain common scenario. In actual life, it is affected by the frost accumulation amount on the evaporator (frost accumulation is related to the water content of the food stored in the compartment, the number of times the door is opened, door seal cold leakage, etc.), the number of foods stored, the defrosting interval period, etc. Positive compensation needs to be carried out on the input power to prevent incomplete defrosting.

[0058] Through the above analysis, defrosting is naturally divided into three stages: ice temperature rise, ice melting into water, and defrosting water temperature rise. These three stages are identified by reading the temperature of the sensors arranged on the edge of the evaporator. When the temperature T is lower than 0 °C - Toff, it is regarded as the ice temperature rise stage; when the temperature T is between 0 °C ± Toff, it is regarded as the ice phase change to water stage; when the temperature T is higher than 0 °C + Toff, it is regarded as the defrosting water temperature rise stage (to prevent the 0 °C water from refreezing and blocking the drain hole during the dripping process).

[0059] The input power compensation strategy adopts the classic position type PI control model. As for why the differential link is not introduced and the incremental PID control algorithm is used, the main reason is that the controlled object (the temperature near the evaporator) has a large thermal inertia and little signal fluctuation.

[0060] Its theoretical formula is as follows:

[0061]

[0062] Pc: Compensated input power;

[0063] Kp: Proportional coefficient;

[0064] Te: The difference between the target temperature and the current frost temperature. For example, the target temperature during the frost temperature rising stage is T0.

[0065] Ti: Integration time constant;

[0066] Since the classical position-type PI control model is applicable to continuous control signals, in digital controllers such as single-chip microcomputers, the continuous signal is segmented into several fine time points (one sampling period between two adjacent points) for approximate fitting, that is, data discretization processing. T is used as the sampling period, k is used as the sampling sequence number, and the rectangular method is used to approximately replace the integral by data accumulation. In this way, the integral becomes the accumulation sum of a finite number of data, and the differential becomes the first-order backward difference. The PI control model after data discretization is:

[0067]

[0068] Pc: Compensated input power;

[0069] Kp: Proportional coefficient;

[0070] Te: The difference between the target temperature and the current frost temperature. For example, the target temperature during the frost temperature rising stage is T0.

[0071] Ti: Integration time constant;

[0072] T: Sampling period;

[0073] Generally, we use Kp as the proportional coefficient and Ki as the integral coefficient

[0074] In this way, the compensation control rule for the input power is as follows:

[0075] When the temperature T is lower than 0°C - Toff (Toff is the temperature offset value for latent heat input power determination):

[0076] a. When the heating time of the heater is less than 10 min, P = P1;

[0077] b. When the heating time of the heater at this power is higher than 10 min, add the integral link,

[0078] Pc1 = Kp1[t(k) + Ki1 * ∑[0,k]t(k)];

[0079] When the temperature T is within 0°C ± Toff (Toff is the temperature offset value for latent heat input power determination):

[0080] a. When the heating time of the heater is less than 20 min, P = P2;

[0081] b. When the heating time of the heater at this power is higher than 20 min, add an integral link,

[0082] Pc2 = Kp2[t(k) + Ki2*∑[0,k]t(k)];

[0083] When the temperature T is higher than 0 °C + Toff (Toff is the temperature offset value for judging the latent heat input power):

[0084] a. When the heating time of the heater is less than 15 min, P = P3;

[0085] b. When the heating time of the heater at this power is higher than 15 min, add an integral link,

[0086] Pc3 = Kp3[t(k) + Ki 3*∑[0,k]t(k)];

[0087] It should be noted that if the original sampling data is not digitally filtered, abnormal sampling data may cause the integral to suddenly saturate. For signals with slow-changing input signals, a smoothing filter algorithm is usually used to avoid signal noise interfering with the operation of the controller. In addition, an integral anti-saturation algorithm can also be introduced to only accumulate negative integrals when the maximum input amount is reached, etc.

[0088] It should be noted that the terms "first", "second", etc. in the description of the specification, claims and drawings of this application are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the application described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0089] Optionally, the specific examples in this embodiment can refer to the examples described in the above embodiments, and this embodiment will not be elaborated here.

[0090] The serial numbers of the above embodiments of this application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0091] In the above embodiments of this application, the descriptions of each embodiment have their own emphases. For parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0092] The above are only the preferred embodiments of the present application. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present application, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. A defrosting structure, characterized in that, Comprising: A heat exchange pipeline (1) for flowing a fluid therein; Heat exchange fins (2) connected to the heat exchange pipeline (1); An energizing device connected to the heat exchange fins (2) to energize the heat exchange fins (2), so that the heat exchange fins (2) generate heat; A control module that adjusts the power of the current passed through the energizing device according to the temperature of the frost on the defrosting structure.

2. The defrosting structure according to claim 1, characterized in that, A connection hole (21) is provided on the heat exchange fin (2), and the heat exchange fin (2) is inserted into the connection hole (21).

3. The defrosting structure according to claim 2, characterized in that There are multiple heat exchange pipelines (1), and the multiple heat exchange pipelines (1) are arranged at intervals; there are multiple connection holes (21), and the multiple connection holes (21) are arranged in one-to-one correspondence with the multiple heat exchange pipelines (1).

4. The defrosting structure according to claim 1, wherein There are multiple heat exchange fins (2), and the multiple heat exchange fins (2) are arranged at intervals.

5. The defrosting structure according to claim 1, wherein, There are multiple heat exchange fins (2), and the multiple heat exchange fins (2) are arranged at intervals; the defrosting structure includes a connecting piece (22), one end of the connecting piece (22) is connected to one of the adjacent two heat exchange fins (2), and the other end of the connecting piece (22) is connected to the other of the adjacent two heat exchange fins (2); wherein, the multiple heat exchange fins (2) are arranged along a preset direction, and the energizing device is respectively connected to the two heat exchange fins (2) located at both ends of the multiple heat exchange fins (2).

6. The defrosting structure according to claim 5, wherein, A plurality of the connecting pieces (22) are arranged between two adjacent heat exchange fins (2); the plurality of the connecting pieces (22) between two adjacent heat exchange fins (2) are arranged at intervals to form a heat dissipation groove (23) between two adjacent connecting pieces (22); the heat dissipation groove (23) communicates with the gap between two adjacent heat exchange fins (2).

7. The defrosting structure according to claim 1, characterized in that There are multiple heat exchange fins (2), and the multiple heat exchange fins (2) are arranged at intervals; there are multiple energizing devices, and the multiple energizing devices are connected to the multiple heat exchange fins (2) in one-to-one correspondence.

8. The defrosting structure according to claim 1, characterized in that, The defrosting structure further includes an insulating component (3) sleeved on the heat exchange pipeline (1), an insulating groove (31) is provided on the insulating component (3), and the insulating component (3) is embedded on the heat exchange fin (2) through the insulating groove (31).

9. The defrosting structure according to claim 1, wherein The defrosting structure further includes: A temperature sensor connected to the heat exchange fin (2); the temperature sensor is in signal connection with the control module, and the control module adjusts the power of the current passed through the energizing device according to the temperature value detected by the temperature sensor.

10. A refrigerator, comprising a defrosting structure, characterized in that, The defrosting structure is the defrosting structure according to any one of claims 1 to 9.

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