Frost layer thickness detection unit, defrosting method, refrigerating system and refrigerating equipment

Abstract

The invention relates to the technical field of refrigeration equipment, and provides a frost layer thickness detection unit comprising an evaporator which is arranged in an inclined or horizontal manner; a plurality of piezoelectric sensors are distributed on the detection plate; the evaporator is placed on the detection plate and is pressed and attached to the piezoelectric sensor; one side of the detection plate is also provided with a bottom support part; and the control module is used for receiving a feedback signal of the piezoelectric sensor, judging the thickness of a frost layer on the evaporator and outputting an electric signal delta thickness corresponding to the thickness of the frost layer. Therefore, a plurality of piezoelectric sensors for supporting the evaporator are arranged; the weight change of the evaporator after frosting is converted into a frost layer thickness signal, accurate reference is provided for starting or stopping of defrosting, and the function that defrosting starting and stopping are matched with the actual working condition is achieved. The invention further provides a defrosting method, a refrigerating system and refrigerating equipment.

Description

Technical Field

[0001] The present invention belongs to the technical field of refrigeration equipment, and in particular relates to a frost thickness detection unit, a defrosting method, a refrigeration system and a refrigeration equipment. Background Art

[0002] Common defrosting methods for refrigeration systems include electric heating and hot gas defrosting. Defrosting typically starts after the refrigeration system has been running for a certain period of time, and the defrost duration is usually a pre-set value.

[0003] However, the usage scenarios and working conditions of refrigeration equipment are relatively complex, and the existing defrost control method cannot cope with it flexibly, resulting in problems such as "over-defrosting" or "under-defrosting".

[0004] In summary, the existing technology has obvious inconveniences and defects in actual use, so it is necessary to improve it. Summary of the Invention

[0005] In view of the above-mentioned defects, the present invention mainly provides a frost thickness detection unit to solve the technical problem that the start and exit of defrosting cannot match the actual operating conditions.

[0006] In order to solve the above problems, the present invention provides a frost thickness detection unit, comprising:

[0007] Evaporator, inclined or horizontal;

[0008] A detection plate is provided with a plurality of piezoelectric sensors; the evaporator is placed on the detection plate and pressed against the piezoelectric sensors; a bottom support portion is also provided on one side of the detection plate;

[0009] The control module receives the feedback signal from the piezoelectric sensor, determines the thickness of the frost layer on the evaporator, and outputs an electrical signal δ corresponding to the thickness of the frost layer. 厚 .

[0010] According to the frost thickness detection unit of the present invention, a plurality of water-permeable holes are provided on the detection plate and the bottom support portion.

[0011] According to the frost thickness detection unit of the present invention, the number of the piezoelectric sensors is no less than 10.

[0012] According to the present invention, the frost thickness detection unit further includes a water receiving tray supporting the bottom support portion, and a side support plate supporting the detection plate is fixedly arranged on one side of the water receiving tray; a plurality of side pillars supporting the detection plate are fixedly arranged on the side support plate, and a bottom pillar supporting the bottom support portion is fixedly arranged on the water receiving tray.

[0013] According to the frost thickness detection unit of the present invention, the water receiving tray includes a plurality of inclined plates, and a drainage hole is provided at the bottom of the water receiving tray; a weight sensor is provided on the inclined plate; and the weight sensor is electrically connected to the control module.

[0014] A defrosting control method for a refrigeration system based on the frost layer thickness detection unit includes the following steps:

[0015] Z1, during the operation of the refrigeration system, the frost thickness detection unit detects and feeds back the frost thickness electrical signal δ of the evaporator 厚 ;

[0016] Z2, judge δ 厚 and critical thickness δ 启 The relationship between δ 厚 ≥δ 启 , start the defrost program;

[0017] Z3, during the defrost program, the frost thickness detection unit detects and feeds back the frost thickness electrical signal δ of the evaporator. 厚 ;

[0018] Z4, judge the δ of step Z3 厚 and critical thickness δ 停 The relationship between δ 厚 ≤δ 停 , end the defrost process.

[0019] According to the defrost control method of the present invention, the δ 启 The value range is: 3-5mm; δ 停 The value range is: 0.05mm-0.15mm.

[0020] According to the defrost control method of the present invention, in the Z2 step, when δ 厚 ≥δ 启 ;

[0021] Collect the temperature T of the inlet pipe of evaporator 1 进 , and the temperature of the outlet pipe T 出 ; Judge T 进 -T 出 Relationship with the preset value T0;

[0022] Collect the operating current I of the compressor 运 , judge I 运 Relationship with the preset value I0;

[0023] When T 进 -T 出 ≥T0, while I 运 ≥I0; start the defrost program;

[0024] In the Z4 step, when δ 厚 ≤δ 停 ; Collect data from each weight sensor m 冰 , and judge with m 冰 The relationship between the preset value m0;

[0025] When all weight sensors m 冰 ≤m0, end the defrost process.

[0026] A refrigeration system having the frost thickness detection unit includes a compressor, a condenser, a capillary tube and an evaporator which are cyclically connected in sequence;

[0027] A tee is connected between the compressor and the condenser, and a tee is also connected between the capillary tube and the evaporator;

[0028] A bypass pipe is connected between the two three-way pipes, and a switch valve is provided on the bypass pipe.

[0029] A refrigeration device comprises a box body, wherein at least one storage compartment is provided in the box body; the refrigeration device comprises the frost thickness detection unit, can execute the defrosting method, or comprises the refrigeration system.

[0030] In summary, the frost thickness detection unit of the present invention, by providing multiple piezoelectric sensors supporting the evaporator, converts the weight change of the evaporator after frosting into a frost thickness signal, providing an accurate reference for initiating or exiting defrost, thereby enabling the start and stop of defrost to match actual operating conditions. The present invention also provides a defrost method, a refrigeration system, and a refrigeration device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 2 is a schematic structural diagram of an embodiment of a frost thickness detection unit of the present invention;

[0032] Figure 2 yes Figure 1 Schematic diagram of the structure of the local area;

[0033] Figure 3 2 is a schematic structural diagram of a detection plate of a frost layer thickness detection unit of the present invention;

[0034] Figure 4 It is a structural schematic diagram of the water receiving tray of the frost thickness detection unit of the present invention;

[0035] Figure 5 2 is a schematic structural diagram of an embodiment of a frost thickness detection unit of the present invention;

[0036] Figure 6 This is a schematic structural diagram of the refrigeration system of the present invention in normal working state;

[0037] Figure 7 2. It is a structural schematic diagram of the defrosting working state of the refrigeration system of the present invention;

[0038] Figure 8 It is a schematic structural diagram of the refrigeration equipment of the present invention;

[0039] In the figure: 1-evaporator, 11-heating wire; 2-detection plate, 21-piezoelectric sensor, 22-bottom support, 23-water permeable hole; 3-water receiving tray, 31-bottom support, 32-drain hole, 33-inclined plate, 34-weight sensor; 4-side support plate, 41-side support; 5-compressor, 51-condenser, 52-filter, 53-capillary tube; 6-bypass pipe, 61-on / off valve, 62-tee pipe; 7-box, 71-storage compartment. DETAILED DESCRIPTION

[0040] See also Figure 1 and Figure 2 The present invention provides a frost thickness detection unit, comprising:

[0041] The evaporator 1 is arranged in an inclined or horizontal manner;

[0042] See also Figure 3 , a detection plate 2 is distributed with a plurality of piezoelectric sensors 21; the evaporator 1 is placed on the detection plate 2 and pressed against the piezoelectric sensor 21;

[0043] The control module receives the feedback signal of the piezoelectric sensor 21, determines the thickness of the frost layer on the evaporator 1, and outputs an electrical signal δ corresponding to the thickness of the frost layer. 厚 ;

[0044] When the surface of the evaporator 1 is frosted, its weight increases, and the piezoelectric sensor 21 generates a corresponding electrical signal and feeds the signal back to the control module; the control module has a parser that can convert the signal into an electrical signal corresponding to the thickness of the frost layer δ 厚 And output.

[0045] The thicker the frost layer, the greater the total weight of the corresponding evaporator 1. As the evaporator 1 operates for longer, the frost layer thickness gradually increases. Therefore, changes in the weight of the evaporator 1 generate a varying electrical signal at the piezoelectric sensor 21. The frost layer thickness is then measured experimentally, and the corresponding feedback signal data is input into the analyzer as the basis for determining and outputting the frost layer thickness.

[0046] As an embodiment, the present invention establishes the relationship between the thickness of the frost layer and the thickness electrical signal δ 厚 The way is:

[0047] S1, in a sealed room, connect the evaporator 1 of the frost thickness detection unit to the refrigeration system; and label each piezoelectric sensor 21 to facilitate corresponding identification of the feedback signal;

[0048] Optionally, to reduce errors, the number of piezoelectric sensors 21 is no less than 15 and is evenly distributed in the coverage area of the evaporator 1 .

[0049] S2, the refrigeration system is started, and the refrigerant is charged into the pipe of the evaporator 1; the electrical signal of each piezoelectric sensor 21 at the initial moment is recorded;

[0050] S3, when the refrigeration system is running, the temperature of the closed compartment is detected and the temperature is controlled to be within a smaller fluctuation range, for example, the temperature in the compartment is controlled to be between -15 and -20°C or -25 and -30°C;

[0051] S4, during the operation of the refrigeration system, gas with a certain humidity (e.g., gas with a humidity of 50-80%) is continuously circulated into the compartment; water vapor in the gas condenses on the surface of the evaporator 1 to form a frost layer;

[0052] S5, recording the electrical signals of each piezoelectric sensor 21 at intervals, and detecting the thickness of the frost layer at the position of the evaporator 1 corresponding to each piezoelectric sensor 21, and recording the data;

[0053] Optionally, the present invention detects the thickness of the frost layer by an ice layer thickness detector.

[0054] S6, repeat step S5 multiple times to collect data;

[0055] S7, data is collated and input into the control module to establish feedback electrical signal-frost layer thickness-output electrical signal δ 厚 relationship;

[0056] The present invention verifies and tests the control module to output the electrical signal δ 厚 Can reflect the actual thickness of the frost layer.

[0057] Optionally, the present invention also detects the efficiency of the refrigeration system during the experiment and establishes the corresponding relationship data between the refrigeration efficiency and the frost layer thickness. Then, based on the data, the critical thickness δ of the frost layer for the refrigeration system to start defrosting is determined. 启 And the critical thickness of the frost layer for exiting defrost δ 停 The present invention can accurately determine the start and exit timing of defrosting according to the critical thickness, thereby achieving precise control of the defrosting process.

[0058] The frost thickness detection unit of the present invention is provided with multiple piezoelectric sensors 21 supporting the evaporator 1; the weight change of the evaporator 1 after frosting is converted into a frost thickness signal, providing an accurate reference for starting or exiting defrosting, and realizing the function of matching the start and stop of defrosting with the actual working conditions.

[0059] As an embodiment, a bottom support portion 22 is further provided on one side of the detection plate 2; when the evaporator 1 is placed at an angle, the bottom support portion 22 can support the evaporator 1 and reduce the detection error of the piezoelectric sensor 21;

[0060] Furthermore, the number of the piezoelectric sensors 21 is not less than 10, which can accurately judge the thickness of the frost layer and the distribution of the frost layer on the evaporator 1, providing a basis for controlling the defrosting timing.

[0061] As an embodiment, a plurality of water-permeable holes 23 are provided on the detection plate 2 and the bottom support portion 22; the frost layer can flow away quickly after melting, avoiding accumulation on the evaporator 1 and causing secondary freezing.

[0062] Preferably, the water permeable holes 23 are in the shape of long strips and are arranged parallel to the heat sink of the evaporator 1 or located below the heat sink to facilitate the flow of melt water.

[0063] See also Figure 4 The frost thickness detection unit also includes a water receiving tray 3 supporting the bottom support portion 22, and a side support plate 4 supporting the detection plate 2 is fixed on one side of the water receiving tray 3; when defrosting, melted water or fallen frost can fall directly into the water receiving tray 3.

[0064] Furthermore, a plurality of side pillars 41 supporting the detection plate 2 are fixed on the side support plate 4, and a bottom pillar 31 supporting the bottom support portion 22 is fixed on the water receiving tray 3; a gap is formed between the side pillars 41 and the bottom pillar 31 to facilitate the flow and discharge of melt water or frost.

[0065] As an embodiment, the water receiving tray 3 includes a plurality of inclined plates 33, and a drainage hole 32 is provided at the bottom of the water receiving tray 3; a weight sensor 34 is provided on the inclined plates 33; and the weight sensor 34 is electrically connected to the control module;

[0066] If the fallen frost accumulates in the water receiving tray 3, the weight sensor 34 can detect the weight. After receiving the signal, the control module can extend the defrosting time or increase the defrosting temperature accordingly to promote the melting and discharge of the frost, thereby preventing it from freezing in the water receiving tray 3 after switching to the cooling mode.

[0067] See also Figure 5 The evaporator 1 of the present invention can be a microchannel evaporator or a fin-type evaporator.

[0068] The present invention also provides a defrost control method for a refrigeration system, comprising the following steps:

[0069] Z1, during the operation of the refrigeration system, the frost thickness detection unit detects and feeds back the frost thickness electrical signal δ of the evaporator 1 厚 ;

[0070] Optionally, in step Z1, the frost thickness detection unit feeds back an electrical signal δ 厚 The interval should not exceed 15 minutes;

[0071] Z2, judge δ 厚 and critical thickness δ 启 relationship;

[0072] When δ 厚 ≥δ 启 , start the defrost program;

[0073] As an example, δ 启 The value range is: 3-5mm; those skilled in the art can make adaptive settings based on factors such as the specifications and models of the specific evaporator 1 and the performance design requirements of the refrigeration product.

[0074] Z3, during the defrost program, the frost thickness detection unit detects and feeds back the frost thickness electrical signal δ of the evaporator 1 厚 ;

[0075] Z4, judge the δ of step Z3 厚 and critical thickness δ 停 relationship;

[0076] When δ 厚 ≤δ 停 , end the defrost process;

[0077] As an example, δ 停 The value range is: 0.05mm-0.15mm; those skilled in the art can make adaptive selection based on actual test results.

[0078] As an example, see Figure 5 A heating wire 11 may be provided on the outside of the evaporator 1 of the present invention to defrost by means of electric heating.

[0079] As an embodiment, the defrosting method of the present invention can also be hot air defrosting.

[0080] Combine Figure 6 As an embodiment, in order to accurately determine the start time of the defrost program, the Z2 step, when δ 厚 ≥δ 启 ;

[0081] Collect the temperature T of the inlet pipe of evaporator 1 进, and the temperature of the outlet pipe T 出 ; Judge T 进 -T 出 Relationship with the preset value T0;

[0082] Collect the operating current I of compressor 5 运 , judge I 运 Relationship with the preset value I0;

[0083] When T 进 -T 出 ≥T0, while I 运 ≥I0; start the defrost program;

[0084] When the temperature difference between the inlet and outlet of the evaporator 1 is too large, it indicates that the frost layer has affected the evaporation of the refrigerant. 运 If the value is too large, it means that the refrigeration system cannot achieve the predetermined refrigeration target. The present invention adds two judgment criteria, which can accurately judge the operating condition of the refrigeration system so as to start the defrost program at the right time, thereby improving the control accuracy.

[0085] Optionally, the value range of T0 of the present invention is: 1-2°C;

[0086] Optionally, I0 of the present invention can be set according to actual ambient temperature and refrigeration capacity requirements.

[0087] As an embodiment, in the Z4 step, when δ 厚 ≤δ 停 ; Collect data from each weight sensor 34 m 冰 , and judge with m 冰 The relationship between the preset value m0;

[0088] When all weight sensors 34 m 冰 ≤m0, end the defrost process;

[0089] When the weight values detected by all weight sensors 34 meet the standards, it can be determined that there is no frost remaining in the water receiving tray 3. Optionally, the value range of m0 is 50-100g.

[0090] See also Figure 6 The present invention also provides a refrigeration system having the frost thickness detection unit, comprising a compressor 5, a condenser 51, a capillary tube 53 and an evaporator 1 which are cyclically connected in sequence;

[0091] A three-way pipe 62 is connected between the compressor 5 and the condenser 51 , and a three-way pipe 62 is also connected between the capillary tube 53 and the evaporator 1 ;

[0092] A bypass pipe 6 is connected between the two three-way pipes 62, and a switch valve 61 is provided on the bypass pipe 6;

[0093] When the refrigeration system is operating normally, the switch valve 61 is closed and the refrigerant does not flow through the bypass pipe 6;

[0094] See also Figure 7 During defrosting, the on-off valve 61 is opened, the evaporator 1 is started, and the high-temperature, high-pressure refrigerant directly enters the evaporator 1 through the bypass pipe 6 to melt the frost layer. Because the resistance of the condenser 51 and the capillary tube 53 is much greater than the resistance of the bypass pipe 6, only a small amount of refrigerant flows through the condenser 51.

[0095] Preferably, a filter 52 is connected between the condenser 51 and the capillary tube 53 to remove moisture from the refrigerant.

[0096] The present invention provides a refrigeration device having a box body 7, wherein at least one storage compartment 71 is provided in the box body 7; the refrigeration device has the frost thickness detection unit, can perform the defrosting method, or has the refrigeration system

[0097] Optionally, the refrigeration device of the present invention may be a refrigerator or a freezer.

[0098] In summary, the present invention provides a frost thickness detection unit. By disposing multiple piezoelectric sensors supporting the evaporator, the unit converts the weight change of the frosted evaporator into a frost thickness signal, providing an accurate reference for initiating or discontinuing defrost, thereby enabling the start and stop of defrost to match actual operating conditions. The present invention also provides a defrost method, a refrigeration system, and refrigeration equipment.

[0099] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A frost thickness detection unit, characterized in that: include: Evaporator, inclined or horizontal; A detection board is provided with a plurality of piezoelectric sensors; The evaporator is placed on the detection plate and pressed against the piezoelectric sensor; a bottom support portion is also provided on one side of the detection plate; The control module receives the feedback signal from the piezoelectric sensor, determines the thickness of the frost layer on the evaporator, and outputs an electrical signal δ corresponding to the thickness of the frost layer. 厚 .

2. The frost thickness detection unit according to claim 1, characterized in that: The detection plate and the bottom support are both provided with a plurality of water-permeable holes.

3. The frost thickness detection unit according to claim 1, wherein: The number of the piezoelectric sensors is no less than 10.

4. The frost thickness detection unit according to any one of claims 1 to 3, characterized in that: It also includes a water receiving tray supporting the bottom support part, a side support plate supporting the detection plate is fixed on one side of the water receiving tray; a plurality of side pillars supporting the detection plate are fixed on the side support plate, and a bottom pillar supporting the bottom support part is fixed on the water receiving tray.

5. The frost thickness detection unit according to claim 4, characterized in that: The water receiving tray includes a plurality of inclined plates, and a drainage hole is provided at the bottom of the water receiving tray; a weight sensor is provided on the inclined plates; and the weight sensor is electrically connected to the control module.

6. A defrosting control method for a refrigeration system based on the frost thickness detection unit according to claim 5, characterized in that: The steps include: Z1, during the operation of the refrigeration system, the frost thickness detection unit detects and feeds back the frost thickness electrical signal δ of the evaporator 厚 ; Z2, judge δ 厚 and critical thickness δ 启 The relationship between δ 厚 ≥δ 启 , start the defrost program; Z3, during the defrost program, the frost thickness detection unit detects and feeds back the frost thickness electrical signal δ of the evaporator. 厚 ; Z4, judge the δ of step Z3 厚 and critical thickness δ 停 The relationship between δ 厚 ≤δ 停 , end the defrost process.

7. The defrost control method according to claim 6, characterized in that: The δ 启 The value range is: 3-5mm; δ 停 The value range is: 0.05mm-0.15mm.

8. The defrost control method according to claim 6, wherein: The Z2 step, when δ 厚 ≥δ 启 ; Collect the temperature T of the inlet pipe of evaporator 1 进 , and the temperature of the outlet pipe T 出 ; Judge T 进 -T 出 Relationship with the preset value T0; Collect the operating current I of the compressor 运 , judge I 运 Relationship with the preset value I0; When T 进 -T 出 ≥T0, while I 运 ≥I0; start the defrost program; In the Z4 step, when δ 厚 ≤δ 停 ; Collect data from each weight sensor m 冰 , and judge with m 冰 The relationship between the preset value m0; When all weight sensors m 冰 ≤m0, end the defrost process.

9. A refrigeration system having the frost thickness detection unit according to claim 5, characterized in that: It includes a compressor, a condenser, a capillary tube and an evaporator which are connected in a cycle in sequence; A tee is connected between the compressor and the condenser, and a tee is also connected between the capillary tube and the evaporator; A bypass pipe is connected between the two three-way pipes, and a switch valve is provided on the bypass pipe.

10. A refrigeration device comprising a box body, wherein the box body is provided with at least one storage compartment; The refrigeration device has the frost thickness detection unit according to claim 5, can execute the defrosting method according to any one of claims 6 to 8, or has the refrigeration system according to claim 9.

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