Refrigerant pressure detection circuit and method and refrigerator

Abstract

The embodiment of the invention provides a refrigerant pressure detection circuit and method and a refrigerator, the refrigerant pressure detection circuit comprises a pressure detection module, the pressure detection module comprises a detection capacitor, and the detection capacitor is used for generating a corresponding capacitance value according to refrigerant pressure in an air outlet pipe of a compressor in the refrigerator; the conversion module is connected with the detection capacitor, and the conversion module is used for controlling the detection capacitor to charge and discharge repeatedly under the corresponding capacitance value and outputting a square wave signal according to the charge and discharge state; and the control module is connected with the conversion module, and the control module is used for obtaining the refrigerant pressure in the corresponding compressor air outlet pipe according to the square wave signal. The detection capacitor is used for detecting the pressure of the refrigerant in the air outlet pipe of the compressor, and the locked-rotor condition of the compressor can be speculated according to the pressure of the refrigerant, so that the operation condition of the compressor is monitored, the operation stability of the compressor can be improved, and the risk of capillary tube breakage is reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of detection circuits, and in particular, relates to a refrigerant pressure detection circuit, method and refrigerator. Background Art

[0002] In the refrigerator's refrigeration system, the capillary tube is used to adjust the system pressure and flow. When the capillary tube is blocked by foreign matter, the refrigerant cannot pass through, which will cause the compressor to stall and over-current, and in severe cases, the capillary tube will burst. However, in the related art, it is impossible to troubleshoot the stall of the compressor. Summary of the invention

[0003] The present application provides a refrigerant pressure detection circuit, method and refrigerator, which can detect the refrigerant pressure to check the compressor jam.

[0004] In a first aspect, an embodiment of the present application provides a refrigerant pressure detection circuit, which is applied to a refrigerator. The refrigerant pressure detection circuit includes:

[0005] A pressure detection module, the pressure detection module comprising a detection capacitor, the detection capacitor being used to generate a corresponding capacitance value according to the refrigerant pressure in the compressor outlet pipe of the refrigerator;

[0006] A conversion module, connected to the detection capacitor, the conversion module is used to control the detection capacitor to repeatedly charge and discharge at a corresponding capacitance value, and output a square wave signal according to the charge and discharge state;

[0007] A control module is connected to the conversion module, and is used to obtain the corresponding refrigerant pressure in the compressor outlet pipe according to the square wave signal.

[0008] Optionally, the conversion module includes:

[0009] A timer, wherein the trigger port and the threshold port of the timer are respectively connected to the two ends of the detection capacitor, the output port of the timer is connected to the control module, the ground port of the timer is grounded, and the reset port of the timer is connected to the power supply.

[0010] Optionally, the conversion module further includes:

[0011] a first resistor, one end of the first resistor being connected to a discharge port of the timer, and the other end of the first resistor being connected to a power supply;

[0012] a second resistor, one end of the second resistor being connected to the trigger port of the timer, and the other end of the second resistor being connected to the discharge port of the timer;

[0013] A first capacitor, one end of the first capacitor is connected to a power port of the timer and the other end of the first resistor, and the other end of the first capacitor is grounded;

[0014] A second capacitor, one end of the second capacitor is connected to the control port of the timer, and the other end of the second capacitor is grounded.

[0015] Optionally, the control module is specifically used to obtain the frequency value of the square wave signal, and obtain the refrigerant pressure in the compressor outlet pipe according to a mapping relationship between a preset frequency value and a refrigerant pressure value.

[0016] Optionally, the control module includes:

[0017] A frequency calculator, connected to the conversion module, and used for obtaining a frequency value of the square wave signal according to the square wave signal;

[0018] A controller is connected to the frequency calculator, and is used to obtain the refrigerant pressure in the compressor outlet pipe according to the frequency value and the mapping relationship.

[0019] Optionally, the distance between the two plates of the detection capacitor is inversely correlated with the refrigerant pressure in the compressor outlet pipe.

[0020] In a second aspect, an embodiment of the present application further provides a refrigerator, comprising:

[0021] A refrigerant pressure detection circuit as described in any one of the above items;

[0022] The compressor outlet pipe, the detection capacitor is arranged in the compressor outlet pipe.

[0023] Optionally, the refrigerator further includes a mounting member, wherein the mounting member is connected to the compressor outlet pipe, the mounting member has a mounting groove, the mounting groove is communicated with the compressor outlet pipe, and the detection capacitor is disposed in the mounting groove.

[0024] Optionally, a side of the detection capacitor facing the compressor outlet pipe is flush or approximately flush with an inner wall of the compressor outlet pipe.

[0025] In a third aspect, an embodiment of the present application further provides a refrigerant pressure detection method, which is applied to a refrigerator, wherein the refrigerator is provided with a detection capacitor, and the detection capacitor is used to generate a corresponding capacitance value according to the refrigerant pressure in the compressor outlet pipe of the refrigerator; the refrigerant pressure detection method comprises:

[0026] Controlling the detection capacitor to repeatedly charge and discharge at the corresponding capacitance value, and obtaining a corresponding square wave signal according to the charging and discharging state;

[0027] The corresponding refrigerant pressure in the compressor outlet pipe is obtained according to the square wave signal.

[0028] In the refrigerant pressure detection circuit, method and refrigerator of the embodiments of the present application, the refrigerant pressure in the compressor outlet pipe is detected by using a detection capacitor, and the compressor stall condition can be inferred based on the refrigerant pressure, thereby realizing the monitoring of the compressor operation condition, which can improve the stability of the compressor operation and reduce the risk of capillary rupture. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0030] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings. In the following description, the same reference numerals represent the same parts.

[0031] Figure 1 A structural block diagram of a refrigerant pressure detection circuit provided in an embodiment of the present application.

[0032] Figure 2 A circuit diagram of a refrigerant pressure detection circuit provided in an embodiment of the present application.

[0033] Figure 3 This is another circuit diagram of the refrigerant pressure detection circuit provided in an embodiment of the present application.

[0034] Figure 4 A schematic diagram of the structure of the detection capacitor and the compressor outlet pipe in the refrigerator provided in the embodiment of the present application.

[0035] Figure 5 A schematic flow chart of a refrigerant pressure detection method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0037] When the refrigerator capillary is blocked by foreign matter, the refrigerant cannot pass through, which will cause the compressor to stall and overcurrent. If the stall parameters are set improperly, the capillary may burst. Since there is no communication between the frequency converter board and the main control board, and the compressor is driven by the frequency converter board, the cause of the compressor stall cannot be identified.

[0038] In order to monitor the stall condition of the compressor and reduce the risk of capillary burst, the embodiments of the present application provide a refrigerant pressure detection circuit, method and refrigerator, which will be described below in conjunction with the accompanying drawings.

[0039] See also Figure 1 As shown, Figure 1 The present invention provides a refrigerant pressure detection circuit 100 for use in a refrigerator. The refrigerant pressure detection circuit 100 includes a pressure detection module 110 , a conversion module 120 and a control module 130 .

[0040] The pressure detection module 110 is used to detect the refrigerant pressure in the compressor outlet pipe in the refrigerator. The compressor outlet pipe corresponds to the front end of the capillary tube. The refrigerant pressure in this part can reflect the stalling of the compressor and the blockage of the capillary tube. Exemplarily, the pressure detection module 110 includes a detection capacitor CJ, which is used to generate a corresponding capacitance value according to the refrigerant pressure in the compressor outlet pipe in the refrigerator.

[0041] It should be noted that the size of the capacitor is related to the dielectric constant, the area of ​​the capacitor plates, and the distance between the capacitor plates. The change in refrigerant pressure is used to drive one of the capacitor plates to move, changing the distance between the capacitor plates to affect the size of the capacitance value. Using this principle, the refrigerant pressure in the compressor outlet pipe can be detected by detecting the capacitor CJ.

[0042] Among them, since the capacitor has the function of isolating direct current, less static current will be generated, thereby reducing the static power consumption of the refrigerant pressure detection circuit.

[0043] The conversion module 120 is connected to the detection capacitor CJ. The conversion module 120 is used to control the detection capacitor CJ to repeatedly charge and discharge at a corresponding capacitance value, and output a square wave signal according to the charging and discharging state.

[0044] The control module 130 is connected to the conversion module 120 , and is used to obtain the refrigerant pressure in the corresponding compressor outlet pipe according to the square wave signal.

[0045] In the refrigerant pressure detection circuit 100 of the embodiment of the present application, the refrigerant pressure in the compressor outlet pipe is detected by using the detection capacitor CJ. The stall condition of the compressor can be inferred based on the refrigerant pressure, thereby monitoring the operating condition of the compressor, improving the stability of the compressor operation, and reducing the risk of capillary rupture.

[0046] For example, see Figure 2 , Figure 2 A circuit diagram of a refrigerant pressure detection circuit provided in an embodiment of the present application. The conversion module 120 includes a timer T1, a first resistor R1, a second resistor R2, a first capacitor C1 and a second capacitor C2.

[0047] The trigger port TRIG and threshold port THRES of the timer T1 are respectively connected to the two ends of the detection capacitor CJ, the output port OUT of the timer T1 is connected to the control module 130, the ground port GND of the timer T1 is connected to the ground GND, and the reset port RESET of the timer T1 is connected to a power supply such as a +5V power supply.

[0048] One end of the first resistor R1 is connected to the discharge port DISCH of the timer T1, and the other end of the first resistor R1 is connected to the power supply.

[0049] One end of the second resistor R2 is connected to the trigger port TRIG of the timer T1 , and the other end of the second resistor R2 is connected to the discharge port DISCH of the timer T1 .

[0050] One end of the first capacitor C1 is connected to the power port VCC of the timer T1 and the other end of the first resistor R1 , and the other end of the first capacitor C1 is grounded GND.

[0051] One end of the second capacitor C2 is connected to the control port CONT of the timer T1 , and the other end of the second capacitor C2 is grounded GND.

[0052] For example, the conversion module 120 may select an integrated chip such as an LM555IN timer, which can simplify the circuit structure, and use finished chips to reduce the manufacturing cost of the refrigerant pressure detection circuit 100.

[0053] Exemplarily, the control module 130 is specifically configured to obtain a frequency value of the square wave signal, and obtain the refrigerant pressure in the compressor outlet pipe according to a mapping relationship between a preset frequency value and a refrigerant pressure value.

[0054] It should be noted that the mapping relationship between the preset frequency value and the refrigerant pressure value can be established by detecting the refrigerant pressure value in the compressor outlet pipe and the capacitance value of the detection capacitor CJ through a testing instrument, establishing a corresponding relationship between the capacitance value of the detection capacitor CJ and the refrigerant pressure value, and then obtaining the corresponding relationship between the frequency value from the capacitance value of the detection capacitor CJ and the square wave signal measured by the conversion module 120, thereby obtaining the mapping relationship between the preset frequency value and the refrigerant pressure value. Therefore, the refrigerant pressure in the compressor outlet pipe can be obtained through the mapping relationship by using the frequency of the square wave signal detected by the refrigerant pressure detection circuit 100.

[0055] For example, see Figure 3 , Figure 3 Another circuit diagram of the refrigerant pressure detection circuit provided in an embodiment of the present application. The control module 130 includes a frequency calculator 131 and a controller 132. The frequency calculator 131 is connected to the conversion module 120, and the frequency calculator 131 is used to obtain the frequency value of the square wave signal. The controller 132 is connected to the frequency calculator 131, and the controller 132 is used to obtain the refrigerant pressure in the compressor outlet pipe according to the frequency value and the mapping relationship.

[0056] In some embodiments, the frequency calculator 131 may be integrated into the controller 132 , such as integrating the frequency calculator 131 and the controller 132 into a single chip microcomputer, so as to save device configuration and thereby improve integration and space utilization.

[0057] Exemplarily, the acquisition process of the detection capacitor CJ and the conversion module 120 is as follows: the power supply +5V charges the detection capacitor CJ through the first resistor R1 and the second resistor R2. When the voltage of the detection capacitor CJ is less than 1 / 3*5V, the oscillator, that is, the output port OUT of the timer T1, outputs 5V, and the discharge tube is cut off. When the voltage of the detection capacitor CJ is charged to be greater than or equal to 2 / 3*5V, the oscillator, that is, the output port OUT of the timer T1, outputs 0V. At this time, the discharge tube is turned on, so that the discharge port DISCH of the timer T1 is grounded, and the power supply +5V charges the detection capacitor CJ through the first resistor R1 and the second resistor R2. This cycle repeats, so that a continuously changing oscillation pulse waveform, that is, a square wave signal, is obtained at the output port OUT of the timer T1.

[0058] Among them, the pulse width TL≈0.7R2*C, which is determined by the discharge time of the detection capacitor CJ; the pulse width TH=0.7(R1+R2)*C, which is determined by the charging time of the detection capacitor CJ, and the pulse period T≈TH+TL. Since the resistances of the first resistor R1 and the second resistor R2 are fixed, the TL and TH widths are obtained by the interrupt collection of the microcontroller, so C=TH / (0.7(R1+R2)).

[0059] Since the determining formula of the capacitor is C = εS / 4πkd, where ε is a constant, S is the area of ​​the capacitor plates, d is the distance between the capacitor plates, and k is the electrostatic force constant, it can be seen that the distance between the two plates of the detection capacitor CJ is inversely proportional to the capacitance value.

[0060] According to the formulas of the above two capacitors, it can be known that the distance between the two plates of the detection capacitor CJ is inversely correlated with the pulse width, while the pulse width is inversely correlated with its frequency. Therefore, it can be concluded that the distance between the two plates of the detection capacitor CJ is positively correlated with the pulse frequency.

[0061] It should be noted that the distance between the two plates of the detection capacitor CJ is inversely correlated with the refrigerant pressure in the compressor outlet pipe, that is, the smaller the distance between the two plates of the detection capacitor CJ, the greater the refrigerant pressure in the compressor outlet pipe. The frequency value of the square wave signal obtained by the conversion module 120 is positively correlated with the distance between the two plates of the detection capacitor CJ, and thus the frequency value of the square wave signal is inversely correlated with the refrigerant pressure in the compressor outlet pipe, that is, the smaller the frequency value of the square wave signal output by the conversion module 120, the greater the refrigerant pressure in the compressor outlet pipe.

[0062] Furthermore, based on the frequency value of the square wave signal detected by the conversion module 120 and the mapping relationship between the preset frequency value and the refrigerant pressure value of the compressor outlet pipe, the refrigerant pressure of the compressor outlet pipe can be obtained, thereby realizing the detection of the refrigerant pressure of the compressor outlet pipe by detecting the change in the capacitance value of the capacitor CJ.

[0063] For example, the refrigerant pressure in the compressor outlet pipe is measured in a range of 0.5 KPa to 2 MPa, and the measurement accuracy may be 0.1 KPa. The pressure range of the refrigerant in the refrigerator compressor, such as refrigerant R600a, is 0.8 MPa to 1.4 MPa during operation.

[0064] It should be noted that, based on the comparison between the pressure P1 of the refrigerant when the compressor is working and the pressure P2 of the refrigerant R600a obtained by the control module 130 such as a single chip, a data calculation model can be suggested to process and compensate for parameters such as temperature drift, pipe inner diameter, and pipe thickness to reduce acquisition errors. A large number of extreme experiments have tested the maximum pressure resistance range of the capillary tube from P3 to P4, and set a threshold value P5, P5 < P3. Once P2 is greater than P5 when the compressor is working, the compressor is immediately shut down, an alarm code is displayed, and a beep is sounded, thereby protecting the compressor and the capillary tube.

[0065] For example, the refrigerant pressure detection circuit 100 of the embodiment of the present application can set the detection cycle according to different working modes. For example, in the energy-saving working mode, the refrigerant pressure is only turned on when the compressor is working, and the detection is performed every 1s. For example, in the normal working mode, the refrigerant pressure is detected every 20ms when the compressor is working. The above method can effectively detect the refrigerant pressure and reduce the risk of capillary rupture when the refrigerator is working.

[0066] For example, see Figure 4 , Figure 4 The schematic diagram of the structure of the detection capacitor and the compressor outlet pipe in the refrigerator provided in the embodiment of the present application. The embodiment of the present application also provides a refrigerator 300, the refrigerator 300 includes a refrigerant pressure detection circuit 100 and a compressor outlet pipe 210, and the detection capacitor CJ is arranged in the compressor outlet pipe 210. Of course, the refrigerator 300 is not limited to the above components, and also includes more components such as a compressor, a capillary tube, a display panel, a door body, a refrigerated compartment, etc., which are not limited here.

[0067] It should be noted that the detection capacitor CJ should be able to be driven by the refrigerant pressure, because the refrigerant pressure is needed to drive at least one plate of the detection capacitor CJ to move, so that the refrigerant pressure can be detected by the change in the distance between the two plates of the detection capacitor CJ; at the same time, the setting of the detection capacitor CJ should not affect the flow rate of the refrigerant. Therefore, the embodiment of the present application sets the detection capacitor CJ in the compressor outlet pipe 210.

[0068] Exemplarily, the refrigerator 300 further includes a mounting member 220, the mounting member 220 is connected to the compressor outlet pipe 210, the mounting member 220 has a mounting groove 221, the mounting groove 221 is communicated with the compressor outlet pipe 210, and the detection capacitor CJ is disposed in the mounting groove 221. For example, the side of the detection capacitor CJ facing the compressor outlet pipe 210 is flush or approximately flush with the inner wall of the compressor outlet pipe 210, so as to reduce the influence of the detection capacitor CJ on the refrigerant flow.

[0069] In the refrigerator 300 provided in the embodiment of the present application, by setting the detection capacitor CJ in the compressor outlet pipe 210, and the detection capacitor CJ is flush or approximately flush with the inner wall of the compressor outlet pipe 210, the refrigerant pressure can be detected without affecting the refrigerant flow rate, the detection method is simple, and the space utilization rate is high.

[0070] In order to better implement the refrigerant pressure detection circuit of the embodiment of the present application, the embodiment of the present application also provides a refrigerant pressure detection method, please refer to Figure 5 , Figure 5The flow chart of the refrigerant pressure detection method provided in the embodiment of the present application is as follows. The refrigerant pressure detection method is applied to a refrigerator, and the refrigerator is provided with a detection capacitor, which is used to generate a corresponding capacitance value according to the refrigerant pressure in the outlet pipe of the compressor in the refrigerator. The detection capacitor can refer to Figures 1 to 4 Please refer to the above description, which will not be repeated here. The refrigerant pressure detection method includes:

[0071] 410. Control the detection capacitor to repeatedly charge and discharge at a corresponding capacitance value, and obtain a corresponding square wave signal according to the charge and discharge state.

[0072] The size of the capacitor is related to the dielectric constant, the area of ​​the capacitor plates, and the distance between the capacitor plates. The change in refrigerant pressure is used to drive one of the capacitor plates to move, changing the distance between the capacitor plates to affect the size of the capacitance value. This principle can be used to detect the refrigerant pressure in the compressor outlet pipe by detecting the capacitor.

[0073] By using the above principle, the detection capacitor can be controlled to charge and discharge repeatedly at a corresponding capacitance value, and a corresponding square wave signal can be obtained according to the charging and discharging state.

[0074] 420. Obtain the refrigerant pressure in the corresponding compressor outlet pipe according to the square wave signal.

[0075] For example, the refrigerant pressure in the compressor outlet pipe may be obtained according to the frequency value of the square wave signal and the mapping relationship between the preset frequency value and the refrigerant pressure value.

[0076] The mapping relationship between the preset frequency value and the refrigerant pressure value can be obtained by testing the refrigerant pressure value in the compressor outlet pipe and the capacitance value of the detection capacitor through a testing instrument, establishing a corresponding relationship between the capacitance value of the detection capacitor and the refrigerant pressure value, and then obtaining the corresponding relationship between the frequency value from the capacitance value of the detection capacitor and the measured square wave signal, thereby obtaining the mapping relationship between the preset frequency value and the refrigerant pressure value, and thus the refrigerant pressure in the compressor outlet pipe can be obtained through the mapping relationship by detecting the frequency of the square wave signal.

[0077] In the refrigerant pressure detection method provided in the embodiment of the present application, the refrigerant pressure in the compressor outlet pipe is detected by using a detection capacitor, and the compressor stall condition can be inferred based on the refrigerant pressure, thereby realizing the monitoring of the compressor operation condition, which can improve the stability of the compressor operation and reduce the risk of capillary rupture.

[0078] A person of ordinary skill in the art will appreciate that all or part of the steps in the various methods of the above embodiments may be completed by instructions, or by controlling related hardware through instructions. The instructions may be stored in a computer-readable storage medium and loaded and executed by a processor.

[0079] To this end, an embodiment of the present application provides a computer-readable storage medium, in which multiple computer programs are stored. The computer programs can be loaded by a processor to execute the steps in the refrigerant pressure detection method provided in the embodiment of the present application.

[0080] The storage medium may include: a read-only memory (ROM), a random access memory (RAM), a magnetic disk, an optical disk, or other media that can store program codes.

[0081] Since the computer program stored in the storage medium can execute the steps in the refrigerant pressure detection method provided in the embodiments of the present application, the beneficial effects that can be achieved by any refrigerant pressure detection method provided in the embodiments of the present application can be achieved. Please refer to the previous embodiments for details and will not be repeated here.

[0082] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0083] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features.

[0084] The above is a detailed introduction to the refrigerant pressure detection circuit, method and refrigerator provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for technical personnel in this field, according to the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A refrigerant pressure detection circuit, applied to a refrigerator, characterized in that: The refrigerant pressure detection circuit comprises: A pressure detection module, the pressure detection module comprising a detection capacitor, the detection capacitor being used to generate a corresponding capacitance value according to the refrigerant pressure in the compressor outlet pipe of the refrigerator; A conversion module, connected to the detection capacitor, the conversion module is used to control the detection capacitor to repeatedly charge and discharge at a corresponding capacitance value, and output a square wave signal according to the charge and discharge state; A control module is connected to the conversion module, and is used to obtain the corresponding refrigerant pressure in the compressor outlet pipe according to the square wave signal.

2. The refrigerant pressure detection circuit according to claim 1, characterized in that: The conversion module comprises: A timer, wherein the trigger port and the threshold port of the timer are respectively connected to the two ends of the detection capacitor, the output port of the timer is connected to the control module, the ground port of the timer is grounded, and the reset port of the timer is connected to the power supply.

3. The refrigerant pressure detection circuit according to claim 2, characterized in that: The conversion module also includes: a first resistor, one end of the first resistor being connected to a discharge port of the timer, and the other end of the first resistor being connected to a power supply; a second resistor, one end of the second resistor being connected to the trigger port of the timer, and the other end of the second resistor being connected to the discharge port of the timer; A first capacitor, one end of the first capacitor is connected to a power port of the timer and the other end of the first resistor, and the other end of the first capacitor is grounded; A second capacitor, one end of the second capacitor is connected to the control port of the timer, and the other end of the second capacitor is grounded.

4. The refrigerant pressure detection circuit according to claim 1, characterized in that: The control module is specifically used to obtain the frequency value of the square wave signal, and obtain the refrigerant pressure in the compressor outlet pipe according to a mapping relationship between a preset frequency value and a refrigerant pressure value.

5. The refrigerant pressure detection circuit according to claim 4, characterized in that: The control module comprises: A frequency calculator, connected to the conversion module, and used for obtaining a frequency value of the square wave signal according to the square wave signal; A controller is connected to the frequency calculator, and is used to obtain the refrigerant pressure in the compressor outlet pipe according to the frequency value and the mapping relationship.

6. The refrigerant pressure detection circuit according to any one of claims 1 to 5, characterized in that: The distance between the two plates of the detection capacitor is inversely correlated with the refrigerant pressure in the compressor outlet pipe.

7. A refrigerator, characterized in that: include: The refrigerant pressure detection circuit according to any one of claims 1 to 6; The compressor outlet pipe, the detection capacitor is arranged in the compressor outlet pipe.

8. The refrigerator according to claim 7, characterized in that: The refrigerator also includes a mounting member, which is connected to the compressor outlet pipe. The mounting member has a mounting groove, which is communicated with the compressor outlet pipe. The detection capacitor is arranged in the mounting groove.

9. The refrigerator according to claim 8, characterized in that: The side of the detection capacitor facing the compressor outlet pipe is flush or approximately flush with the inner wall of the compressor outlet pipe.

10. A refrigerant pressure detection method, characterized in that: The refrigerant pressure detection method is applied to a refrigerator, wherein the refrigerator is provided with a detection capacitor, and the detection capacitor is used to generate a corresponding capacitance value according to the refrigerant pressure in the air outlet pipe of the compressor in the refrigerator; The refrigerant pressure detection method comprises: Controlling the detection capacitor to repeatedly charge and discharge at the corresponding capacitance value, and obtaining a corresponding square wave signal according to the charging and discharging state; The corresponding refrigerant pressure in the compressor outlet pipe is obtained according to the square wave signal.

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