WO2019223423A1

WO2019223423A1 - Detection circuit, method and device for detecting water temperature of water chilling unit in air conditioner

Info

Publication number: WO2019223423A1
Application number: PCT/CN2019/080106
Authority: WO
Inventors: 刘玉辉; 程绍江; 时斌
Original assignee: 青岛海尔空调电子有限公司
Priority date: 2018-05-22
Filing date: 2019-03-28
Publication date: 2019-11-28
Also published as: CN108593133A

Abstract

Disclosed are a detection circuit, a method and a device for detecting the water temperature of a water chilling unit in an air conditioner, which are applied to the technical field of air conditioners. The detection circuit comprises: a temperature acquisition unit (1), a differential amplification unit (2) and a data processing unit (3), wherein the temperature acquisition unit (1) is used to convert a resistance value of a platinum thermistor for measuring the water temperature of a water chilling unit in an air conditioner into a first voltage value and a second voltage value; the differential amplification unit (2) is used to amplify a voltage difference value of the first voltage value and the second voltage value and then output the amplified voltage difference value, so as to acquire an output voltage; and the data processing unit (3) is used to convert the output voltage into a digital signal, and acquire a corresponding detection temperature according to the digital signal and display same. The detection circuit, the method and the device solve the problems of low detection accuracy and unstable temperature detection by using a negative temperature coefficient thermistor for chilled water temperature detection.

Description

Detection circuit, method and device for detecting water temperature of chiller in air conditioner

This application is based on a Chinese patent application with an application number of 201810496140.0 and an application date of May 22, 2018, and claims the priority of the Chinese patent application. The entire contents of the Chinese patent application are incorporated herein by reference.

Technical field

The present application relates to the technical field of air conditioning, for example, to a detection circuit, method, and device for detecting a water temperature of a chiller in an air conditioner.

Background technique

At present, the operating range of the chiller water temperature is generally in the range of -25 ° C to 65 ° C. Thermal resistance is the most commonly used temperature detector in the low and medium temperature regions. The traditional cold-water unit uses a negative temperature coefficient thermistor (NTC) to detect the water temperature. The circuit is basically composed of a VCC power module, a voltage-dividing resistor module, and an NTC temperature sensor module. The water temperature changes and the corresponding relationship between the resistance and the temperature can be obtained by a preset table lookup method. The accuracy of the temperature detection is generally around ± 1 ° C. Especially, the accuracy is lower than zero, and the temperature detection is unstable, which causes problems such as slow temperature adjustment and unstable control of the unit.

Summary of the Invention

The embodiments of the present disclosure provide a detection circuit, a method, and a device for detecting the water temperature of a chiller in an air conditioner. The purpose is to solve the cold water temperature detection using a negative temperature coefficient thermistor (NTC), which has low detection accuracy and temperature detection. Unstable technical issues. In order to have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not a general overview, nor is it intended to identify key / important constituent elements or to describe the scope of protection of these embodiments. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

According to the embodiments of the present disclosure, a detection circuit, a method, and a device for detecting a water temperature of a chiller in an air conditioner are provided. A platinum thermal resistance is applied to the detection circuit to detect a water temperature of the chiller in an air conditioner. The measurement accuracy is relatively high, which can improve the temperature regulation speed and control accuracy of the unit.

According to a first aspect of the embodiments of the present disclosure, there is provided a detection circuit for detecting a water temperature of a chiller in an air conditioner, the detection circuit including:

The temperature acquisition unit is connected to a platinum thermal resistance measuring the water temperature of the chiller in the air conditioner, and is configured to convert the resistance value of the platinum thermal resistance into a first voltage value and a second voltage value;

A differential amplification unit connected to the temperature acquisition unit and configured to amplify and output a voltage difference between the first voltage value and the second voltage value to obtain an output voltage;

A data processing unit is connected to the differential amplifying unit, and is configured to convert the output voltage into a digital signal, and obtain a corresponding detected temperature for display according to the digital signal.

According to a second aspect of the embodiments of the present disclosure, a method for detecting a water temperature of an air-conditioning chiller unit is provided. The method includes:

A voltage difference value determined by measuring a platinum thermal resistance of a water chiller in an air conditioner is obtained, where the voltage difference is between a first voltage value and a second voltage value converted from the resistance value of the platinum thermal resistance The difference is determined after magnification;

The voltage difference is digitally processed to obtain a corresponding detected temperature and displayed.

According to a third aspect of the embodiments of the present disclosure, a device for detecting a water temperature of an air-conditioning chiller unit is provided, and the device includes:

A first obtaining unit is configured to obtain a voltage difference value determined by measuring a platinum thermal resistance of a water chiller in an air conditioner, wherein the voltage difference is a first voltage value converted from a resistance value of the platinum thermal resistance and The difference between the second voltage values is determined after being amplified;

A digital processing unit is configured to digitally process the voltage difference to obtain a corresponding detected temperature and display the detected temperature.

The technical solutions provided by the embodiments of the present disclosure may include the following beneficial effects:

The platinum thermal resistance is applied to the detection circuit to detect the water temperature of the chiller in the air conditioner. The measurement accuracy of the platinum thermal resistance is relatively high, which can improve the temperature adjustment speed and control accuracy of the unit.

It should be understood that the above general description and the following detailed description are merely exemplary and explanatory, and should not limit the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings herein are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure, and together with the description serve to explain the principles of the present disclosure.

Fig. 1 is a schematic structural diagram of a detection circuit according to an exemplary embodiment;

Fig. 2 is another schematic structural diagram of a detection circuit according to an exemplary embodiment;

Fig. 3 is a circuit diagram of a detection circuit according to an exemplary embodiment;

Fig. 4 is a simplified circuit diagram of a differential amplifier unit according to an exemplary embodiment;

Fig. 5 is a simplified circuit diagram of a V _{IN +} terminal of a differential amplifier unit according to an exemplary embodiment;

Fig. 6 is a simplified circuit diagram of a V _IN- terminal of a differential amplifier unit according to an exemplary embodiment;

Fig. 7 is a schematic flowchart of a method for detecting a water temperature of a chiller in an air conditioner according to an exemplary embodiment;

Fig. 8 is a schematic structural diagram of a device for detecting a water temperature of a chiller in an air conditioner according to an exemplary embodiment.

Reference sign description:

1- temperature acquisition unit; 11- voltage regulator sub-unit; 2- differential amplifier unit; 3- data processing unit; 31-A / D converter; 32- single-chip computer; 33- display screen; 4- first acquisition unit; 5-digital processing unit; 6-second acquisition unit; 7-third acquisition unit.

Detailed ways

The following description and drawings sufficiently illustrate specific embodiments of the present disclosure to enable those skilled in the art to practice them. The embodiments represent only possible changes, and unless explicitly required, individual components and functions are optional, and the order of operations may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The scope of the embodiments of this application includes the entire scope of the claims, and all available equivalents of the claims. Herein, the embodiments may be individually or collectively represented by the term "invention", this is for convenience only, and if more than one invention is actually disclosed, it is not intended to automatically limit the scope of the application to any A single invention or inventive idea. In this article, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not require or imply any actual relationship between these entities or operations or order.

It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of the present disclosure are only used to explain the relationship between components in a specific posture (as shown in the drawings). The relative positional relationship, movement situation, etc., if the specific posture changes, the directional indication also changes accordingly. In addition, descriptions such as “first”, “second”, and the like in this application are for descriptive purposes only and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as “first” and “second” may include at least one of these features explicitly or implicitly.

In the description of this application, it should be noted that the terms "installation" and "connection" should be understood in a broad sense unless otherwise specified and limited, for example, they may be fixed connections, detachable connections, or integrated It can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood in specific situations.

The embodiments in this document are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same and similar parts between the embodiments, refer to each other.

Figs. 1 to 3 are schematic structural diagrams of a detection circuit according to an exemplary embodiment.

In this alternative embodiment, as shown in FIG. 1, the detection circuit includes a temperature acquisition unit 1, a differential amplifier unit 2, and a data processing unit 3, wherein the temperature acquisition unit 1 and a water temperature measurement unit of a chiller in an air conditioner A platinum thermal resistance connection for converting the resistance value of the platinum thermal resistance into a first voltage value and a second voltage value, and the differential amplification unit 2 is connected to the temperature acquisition unit 1 for connecting the The voltage difference between the first voltage value and the second voltage value is amplified and output to obtain an output voltage. The data processing unit 3 is connected to the differential amplification unit 2 and is configured to convert the output voltage into A digital signal, and the corresponding detected temperature is obtained for display according to the digital signal.

Optionally, as shown in FIG. 3, the temperature acquisition unit 1 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a second capacitor. C2, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5, wherein the input terminal of the first resistor R1 is connected to the output terminal of the platinum thermal resistor, and the output terminal of the first resistor R1 is connected to the first capacitor R1. An external voltage VCC1 is connected, an input terminal of the second resistor R2 is connected to a first external voltage VCC1, and an output terminal of the second resistor R2 is respectively connected to an input terminal of the third resistor R3 and the third capacitor C3. The input terminal of is connected to the input terminal of the sixth resistor R6, the third resistor R3 and the fourth resistor R4 are connected in series, the input terminal of the fourth resistor R4 and the output terminal of the third resistor R3 Connected, the fourth resistor R4 is grounded, the input terminal of the fifth resistor R5 is connected to the output terminal of the platinum thermal resistor, the output terminal of the fifth resistor R5 is connected to the V _{IN of} the differential amplifier unit 2 _- terminal is connected, an output terminal of the sixth resistor R6 to the differential amplifying unit 2 V _{iN +} terminal connected to the The input terminal of the second capacitor C2 is connected to the output terminal of the platinum thermal resistor, the output terminal of the second capacitor C2 is connected to the output terminal of the second resistor R2, and the output terminal of the third capacitor C3 is grounded, An input terminal of the fourth capacitor C4 is connected to the first external voltage VCC1, an output terminal of the fourth capacitor C4 is grounded, an input terminal of the fifth capacitor C5 is connected to the first external voltage VCC1, and the fifth capacitor C5 The output is grounded.

Optionally, the platinum thermal resistance is a platinum thermal resistance in a PT0 temperature sensor.

Optionally, the size of the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 is 0.1uf, and the withstand voltage is 50V. Mainly plays a filtering role.

Optionally, the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 mainly function as a voltage divider, and the fifth resistor R5 and the sixth resistor R6 mainly plays a role of current limiting. The accuracy of the first resistor R1, the second resistor R2, and the third resistor R3 is within a range of ± 1%. The higher the accuracy, the smaller the circuit error.

Optionally, as shown in FIG. 3, the temperature acquisition unit 1 further includes a plug-in connector CN1, and the platinum thermal resistor is connected to the detection circuit through the plug-in connector. Optionally, the model of the plug-in connector CN1 is B2B-XH-A. The use of the plug-in connector CN1 can improve the flexibility of the detection circuit design, and at the same time, facilitate the replacement and maintenance of the platinum thermal resistor.

Optionally, the temperature acquisition unit 1 further includes a voltage stabilizing unit 11 including a voltage stabilizing tube and a capacitor connected in parallel. As shown in FIG. 3, the voltage stabilizing unit 11 includes a parallel The connected Zener tube TVS1 and the first capacitor C1, wherein the input terminal of the Zener tube TVS1 is connected to the output terminal of the platinum thermal resistor, the output terminal of the Zener tube TVS1 is grounded, and the first An input terminal of a capacitor C1 is connected to an output terminal of the platinum thermal resistor, and an output terminal of the first capacitor C1 is grounded. Optionally, the size of the first capacitor C1 is 0.1 uf, and the withstand voltage of the first capacitor C1 is 50V. Optionally, the model of the voltage regulator TVS1 is HTVSB5.0CA-100. The voltage stabilizing subunit 11 plays a voltage stabilizing role, and its main function is to protect the differential amplifier unit 2.

Optionally, as shown in FIG. 3, a common ground voltage VSS terminal of the differential amplifier unit 2 is grounded, a reference voltage Ref terminal of the differential amplifier unit 2 is grounded, and an internal voltage of the differential amplifier unit 2 is connected. The VCC terminal is connected to the second external voltage VCC2.

Optionally, the differential amplifier unit 2 uses an INA156 chip.

Optionally, the data processing unit 3 is specifically configured to convert the output voltage into the digital signal through an A / D converter 31. Optionally, as shown in FIG. 3, the data processing unit 3 includes an A / D converter 31, a seventh resistor R7, an eighth resistor R8, a sixth capacitor C6, a seventh capacitor C7, and an eighth capacitor C8, where The input terminal of the seventh resistor R7 is connected to the output voltage VOUT terminal of the differential amplifier unit 2. The output terminal of the seventh resistor R7 is respectively connected to the input terminal of the eighth resistor R8 and the sixth resistor. The input terminal of the capacitor C6 is connected, and the output terminal of the eighth resistor R8 is connected to the signal input terminal IN of the A / D converter 31 and the input terminal of the eighth capacitor C8, and the sixth capacitor C6 The output terminal of the seventh capacitor C7 is connected to the third external voltage VCC3, the output terminal of the seventh capacitor C7 is connected to the ground, the output terminal of the eighth capacitor C8 is connected to the ground, and the A / D conversion The reference voltage REF terminal of the converter 31 is connected to the third external voltage VCC3, and the signal input terminal -IN terminal of the A / D converter 31 and the GND terminal of the power supply access terminal are grounded.

Optionally, the size of the sixth capacitor C6, the seventh capacitor C7, and the eighth capacitor C8 is 0.1uf, and the withstand voltage is 50V, which mainly plays a filtering role.

Optionally, the seventh resistor R7 and the eighth resistor R8 mainly function as a voltage divider.

Optionally, the A / D converter 31 uses an ADS8325 chip.

Optionally, the data processing unit 3 is specifically configured to convert the output voltage into the digital signal through an A / D algorithm. Optionally, the data processing unit 3 may use program software that can execute an A / D algorithm to convert the output voltage into the digital signal.

It should be noted that the ground in "ground" is not a ground in the true sense, but a ground that is assumed for applications. For a power source, it is the negative pole of a power source. It is different from the earth, sometimes it needs to be connected to the earth, sometimes it is not needed, depending on the specific situation.

Optionally, the data processing unit 3 uses the single-chip microcomputer 32 to obtain the corresponding detected temperature according to the digital signal. Specifically, after conversion, the serial data output from the DOUT end of the A / D converter 31 is transferred to the single-chip microcomputer 32MCU, and the single-chip microcomputer 32MCU looks up the table to obtain the detected temperature.

Optionally, the data processing unit 3 uses the display screen 33 to display the detected temperature. Specifically, the single-chip microcomputer 32MCU is connected to the display screen 33 by means of RS-485 communication, and transmits the detected temperature to the display screen 33. The display screen 33 may be a touch display screen.

In this optional embodiment, a platinum thermal resistance is applied to the detection circuit to detect the water temperature of the chiller in the air conditioner. The measurement accuracy of the platinum thermal resistance is relatively high, which can ensure that the temperature adjustment speed of the unit is fast and the control is accurate. Wider operating range.

In some optional embodiments, the data processing unit 3 is further configured to:

Obtaining a compensation temperature, wherein the compensation temperature is determined according to a temperature resistance value comparison table of the platinum thermal resistance;

According to the detection temperature and the compensation temperature, a corresponding output temperature is obtained and displayed.

Optionally, the data processing unit 3 determines a compensation temperature by using the single-chip microcomputer 32MCU, obtains a corresponding output temperature according to the detection temperature and the compensation temperature, and uses the display screen 33 to display the output temperature.

Optionally, the output temperature can be calculated according to the following formula:

T = T0 + ΔT

Among them, T is the output temperature, T0 is the detection temperature, and ΔT is the compensation temperature. The compensation temperature ΔT is determined according to the temperature resistance value comparison table of the platinum thermal resistance.

Optionally, the compensation temperature can be calculated according to the following formula:

ΔT0 = T _Rt -T _detection

Among them, T _Rt is the temperature determined according to the temperature resistance value comparison table of the platinum thermal resistance when the external resistance Rt is used, and T is the temperature _detected by the detection circuit when the external resistance Rt is used.

For example, the process of obtaining the compensation temperature ΔT is as follows: the external resistance is 1000 ohms. According to the circuit,

V _{IN +} = 0.861V;

V _IN- = 5 * Rt / (10000 + Rt) = 5 * 1000 / (10000 + 1000) = 0.455V;

V _OUT = 10 (V _{IN +} -V _IN- ) = 10 * 0.406V = 4.06V;

Among them, V _{IN +} is the first voltage value, V _IN− is the second voltage value, and Rt is the resistance value of the platinum thermal resistance.

Convert VOUT to an analog value. For a 12-bit AD, if the modulus corresponding to 5V is 4096, then the analog value corresponding to 4.06V = 4.06 * 4096 / 5V = 3325.952, and then passed to the MCU. Due to the inherent error of the circuit and external platinum heat Resistance error, the displayed temperature may be 0.3 ° C. According to the temperature resistance value comparison table of platinum thermal resistance, the table shows that when the external resistance is 1000Ω, it corresponds to 0 ° C. It is necessary to compensate the displayed temperature of 0.3 ° C. It can be seen that the compensation temperature ΔT0 = T _Rt -T _detection = 0 ° -0.3 ° = -0.3 ° C. Other corresponding compensation temperatures ΔT0 are obtained in a similar manner. The temperature and resistance of the platinum thermal resistor are basically linear, so the error is basically the same.

In this optional embodiment, the detection temperature of the detection circuit is corrected to overcome errors caused by the resistance accuracy of the hardware circuit, the lead length of the PT1000 temperature sensor including the platinum thermal resistance, and improve the temperature detection accuracy.

Fig. 4 to Fig. 6 are simplified circuit diagrams of a differential amplifier unit according to an exemplary embodiment.

In this alternative embodiment, V _{IN +} is a constant, V _{IN +} ranges from [0.85, 0.88], V _IN- is a variable, and the voltage is adjusted according to the temperature value of the platinum thermal resistor.

According to Figure 4, Vout = N * (V _{IN +} -V _IN- ), where Vout is the output voltage, N is the amplification factor of the differential amplifier unit 2, V _{IN +} is the first voltage value, and V _IN- is the second voltage value;

According to FIG. 5, V _{IN +} = 5 * R02 / (R01 + R02) = C, where R01 and R02 are resistance values of the resistor, and C is a constant;

According to Fig. 6, V _IN- = 5 * R03 / (R03 + R04) = 5 * Rt / (10000 + Rt), R03 and R04 are resistance values of the resistor, and Rt is resistance value of the platinum thermal resistance;

Then, the differential amplifier unit 2 calculates the output voltage Vout according to the following formula:

Vout = N * [V _{IN +} -5 * Rt / (10000 + Rt)]

Among them, Vout is the output voltage, N is the amplification factor of the differential amplifier unit 2, the range of N is [8,12], V _{IN +} is the first voltage value, and Rt is the resistance value of the platinum thermal resistor.

Fig. 7 is a schematic flowchart of a method for detecting a water temperature of a chiller in an air conditioner according to an exemplary embodiment.

In this optional embodiment, a method for detecting a water temperature of a chiller in an air conditioner is provided. The method includes:

S701: Obtain a voltage difference value determined by measuring a platinum thermal resistance of a water chiller in an air conditioner, wherein the voltage difference is a value between a first voltage value and a second voltage value converted from the resistance value of the platinum thermal resistance. The difference between them is determined after magnification.

S702: Digitally process the voltage difference to obtain a corresponding detected temperature, and display the detected temperature.

S703: Obtain a compensation temperature, where the compensation temperature is determined according to a temperature resistance value comparison table of the platinum thermal resistance.

S704: Obtain and display a corresponding output temperature according to the detection temperature and the compensation temperature.

T = T0 + ΔT

Among them, T is the output temperature, T0 is the detection temperature, and ΔT is the compensation temperature.

The compensation temperature ΔT is determined according to the temperature resistance value comparison table of the platinum thermal resistance.

ΔT0 = T _Rt -T _detection

In this optional embodiment, a device for detecting a water temperature of a chiller in an air conditioner is provided. The device includes:

A first obtaining unit 4 is configured to obtain a voltage difference value determined by measuring a platinum thermal resistance of a water temperature of a chiller in an air conditioner, wherein the voltage difference is a first voltage value converted from a resistance value of the platinum thermal resistance A difference between the second voltage value and the second voltage value is determined after amplification;

A digital processing unit 5 configured to digitally process the voltage difference to obtain a corresponding detected temperature and display it;

The second obtaining unit 6 is configured to obtain a compensation temperature, where the compensation temperature is determined according to a temperature resistance value comparison table of the platinum thermal resistance;

The third obtaining unit 7 is configured to obtain and display a corresponding output temperature according to the detection temperature and the compensation temperature.

Optionally, the third obtaining unit 7 is configured to calculate the output temperature according to the following formula:

T = T0 + ΔT

In some exemplary embodiments, a non-transitory computer-readable storage medium including instructions, such as a memory including instructions, may be executed by a processor to implement the method described above. The non-transitory computer-readable storage medium may be a read-only memory (Read Only Memory, ROM), a random access memory (Random Access Memory, RAM), a magnetic tape, and an optical storage device.

Those skilled in the art may realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present disclosure. Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and are not repeated here.

In the embodiments disclosed herein, it should be understood that the disclosed methods and products (including but not limited to devices, equipment, etc.) may be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner. For example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, which may be electrical, mechanical or other forms. The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objective of the solution of this embodiment. In addition, each functional unit in each embodiment of the present disclosure may be integrated into one processing unit, or each unit may exist separately physically, or two or more units may be integrated into one unit.

It should be understood that the flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram may represent a module, a program segment, or a part of code, which contains one or more components for implementing a specified logical function Executable instructions. It should also be noted that in some alternative implementations, the functions labeled in the blocks may also occur in a different order than those labeled in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented in a dedicated hardware-based system that performs the specified function or action. , Or it can be implemented with a combination of dedicated hardware and computer instructions. The present disclosure is not limited to the processes and structures that have been described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the disclosure is limited only by the following claims.

Claims

A detection circuit for detecting the water temperature of a chiller in an air conditioner is characterized in that it includes:

The temperature acquisition unit is connected to a platinum thermal resistance measuring the water temperature of the chiller in the air conditioner, and is configured to convert the resistance value of the platinum thermal resistance into a first voltage value and a second voltage value;

A differential amplification unit connected to the temperature acquisition unit and configured to amplify and output a voltage difference between the first voltage value and the second voltage value to obtain an output voltage;

A data processing unit is connected to the differential amplifying unit, and is configured to convert the output voltage into a digital signal, and obtain a corresponding detected temperature for display according to the digital signal.
The detection circuit according to claim 1, wherein the data processing unit is further configured to:

Obtaining a compensation temperature, wherein the compensation temperature is determined according to a temperature resistance value comparison table of the platinum thermal resistance;

According to the detection temperature and the compensation temperature, a corresponding output temperature is obtained and displayed.
The detection circuit according to claim 1, wherein the temperature acquisition unit further comprises:

The voltage regulator subunit includes a voltage regulator tube and a capacitor connected in parallel, wherein an input terminal of the voltage regulator tube is connected to an output terminal of the platinum thermal resistor, an output terminal of the voltage regulator tube is grounded, and An input terminal is connected to an output terminal of the platinum thermal resistor, and an output terminal of the capacitor is grounded.
The detection circuit according to claim 1, wherein the differential amplifier unit calculates the output voltage according to the following formula:

Vout = N * [V IN + -5 * Rt / (10000 + Rt)]

Among them, Vout is the output voltage, N is the amplification factor of the differential amplifier unit, V IN + is the first voltage value, and Rt is the resistance value of the platinum thermal resistor.
The detection circuit according to claim 1, wherein:

The data processing unit is specifically configured to convert the output voltage into the digital signal through an A / D converter; or convert the output voltage into the digital signal through an A / D algorithm.
A method for detecting the water temperature of a chiller in an air conditioner, comprising:

A voltage difference value determined by measuring a platinum thermal resistance of a water chiller in an air conditioner is obtained, where the voltage difference is between a first voltage value and a second voltage value converted from the resistance value of the platinum thermal resistance The difference is determined after magnification;

The voltage difference is digitally processed to obtain a corresponding detected temperature and displayed.
The detection method according to claim 6, further comprising:

Obtaining a compensation temperature, wherein the compensation temperature is determined according to a temperature resistance value comparison table of the platinum thermal resistance;

According to the detection temperature and the compensation temperature, a corresponding output temperature is acquired and displayed.
A device for detecting the water temperature of a chiller in an air conditioner is characterized in that it includes:

A first obtaining unit is configured to obtain a voltage difference value determined by measuring a platinum thermal resistance of a water chiller in an air conditioner, wherein the voltage difference is a first voltage value converted from a resistance value of the platinum thermal resistance and The difference between the second voltage values is determined after being amplified;

A digital processing unit is configured to digitally process the voltage difference to obtain a corresponding detected temperature and display the detected temperature.
The apparatus according to claim 8, further comprising:

A second obtaining unit for obtaining a compensation temperature, wherein the compensation temperature is determined according to a temperature resistance value comparison table of the platinum thermal resistance;

The third obtaining unit is configured to obtain and display a corresponding output temperature according to the detection temperature and the compensation temperature.