CN218328593U

CN218328593U - Signal conversion circuit and refrigeration equipment

Info

Publication number: CN218328593U
Application number: CN202222595684.7U
Authority: CN
Inventors: 韩同瑞; 李磊磊
Original assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Current assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Priority date: 2022-09-29
Filing date: 2022-09-29
Publication date: 2023-01-17
Anticipated expiration: 2032-09-29

Abstract

The utility model provides a signal conversion circuit and refrigeration plant, signal conversion circuit includes: an input end; the first pin of the primary side of the optical coupler is connected with the input end through a first resistor, and the second pin of the primary side of the optical coupler is grounded; the secondary side first pin is connected with a power supply through a second resistor; the positive electrode of the first capacitor is connected with the second pin at the secondary side of the optical coupler, and the negative electrode of the first capacitor is grounded; one end of the third resistor is connected with a second pin on the secondary side of the optical coupler, and the negative electrode of the third resistor is grounded; and one end of the output end is connected with a second pin on the secondary side of the optical coupler, and the other end of the output end is connected with the analog-to-digital converter. According to the method and the device, under the condition that the chip port resources do not meet the use requirements, the AD acquisition port resources of the chip are utilized, the pulse width modulation signals output by the refrigerant state detection device are converted into AD voltage signals which can be sampled by the analog-digital sensor through the signal conversion circuit, and the problem that the chip port resources are insufficient is solved.

Description

Signal conversion circuit and refrigeration equipment

Technical Field

The application relates to the technical field of refrigeration equipment, in particular to a signal conversion circuit and refrigeration equipment.

Background

R410A refrigerant and R32 refrigerant are refrigerant media mainly used in conventional air conditioning products, but R32 refrigerant has flammable characteristics, and may cause safety problems under certain conditions (lack of safety awareness or irregular operation, etc.), which is a common risk during installation and maintenance of refrigeration equipment. Therefore, the refrigerant leakage detection device is a new requirement of air-conditioning products, and is used for detecting the refrigerant leakage in time and giving an alarm, so that the refrigerant leakage detection device is required to be used for ensuring the use safety of the air-conditioning products and preventing the refrigerant leakage from causing the accidents of suffocation, deflagration and the like of air-conditioning users and animals in air-conditioning rooms, the refrigerant leakage amount is detected, the shutdown instruction is output in time, the alarm information is given out, and the dangerous case is eliminated in advance.

The detection device for R32 refrigerant leakage can output various states, the states are realized by outputting different PWM duty ratio signals, the signals need to be distinguished when being collected, and the main control board judges whether the refrigerant leakage and other fault problems occur according to the collected information and timely responds.

When the signals are collected, the input capturing function of the main control board chip is required to be occupied, and because the number of pins with the function is small, and some essential functions of the unit already occupy the pins, the functional resources are tense, and the realization is difficult.

Disclosure of Invention

The present application is made in view of the above circumstances, and an object of the present application is to provide a signal conversion circuit and a refrigeration device, which can effectively solve the problem of insufficient use of chip port resources.

In order to solve the above technical problem, a first aspect of the present invention provides a signal conversion circuit. The signal conversion circuit includes: an input end; the first pin of the primary side of the optical coupler is connected with the input end through a first resistor, and the second pin of the primary side of the optical coupler is grounded; the secondary side first pin is connected with a power supply through a second resistor; the positive electrode of the first capacitor is connected with the second pin at the secondary side of the optical coupler, and the negative electrode of the first capacitor is grounded; one end of the third resistor is connected with a second pin on the secondary side of the optical coupler, and the negative electrode of the third resistor is grounded; and one end of the output end is connected with a second pin on the secondary side of the optical coupler, and the other end of the output end is connected with the analog-to-digital converter.

In some optional embodiments of the present application, the input is configured to connect to a refrigerant condition detection device; the refrigerant detection device outputs a pulse width modulation signal.

In some optional embodiments of the present application, a duty cycle of the pulse width modulation signal corresponds to an actual state of the refrigerant detection device.

In some alternative embodiments of the present application, the duty cycles correspond to different refrigerant concentration states.

In some optional embodiments of the present application, the duty ratio corresponds to a power state of the refrigerant state detection device.

In some optional embodiments of the present application, the duty ratio corresponds to a hardware state of the refrigerant state detection device.

In some optional embodiments of the present application, the output parameter of the output end is a voltage value, and the voltage value is positively correlated with the duty ratio.

In some optional embodiments of the present application, a semiconductor-type gas sensor for detecting the concentration of the refrigerant is provided in the refrigerant detection device.

In some alternative embodiments of the present application, a refrigeration appliance is also provided. The refrigeration equipment comprises a main control board, wherein the main control board is provided with the signal conversion circuit.

In some optional embodiments of the present application, a processing chip is further disposed on the main control board, and an analog-to-digital converter is disposed on the processing chip.

According to the method and the device, under the condition that the chip port resources do not meet the use requirements, the AD acquisition port resources of the chip are utilized, the pulse width modulation signals (PWM signals) output by the refrigerant state detection device are converted into the AD voltage values which can be sampled by the analog-digital sensor through the signal conversion circuit, and the problem of insufficient chip port resources is solved. Moreover, the signal conversion circuit realizes signal isolation and improves the anti-interference performance and reliability of signal acquisition.

Drawings

FIG. 1 illustrates a block schematic diagram of a refrigeration appliance, according to some embodiments;

FIG. 2 illustrates a schematic block diagram of a communication structure of a refrigeration appliance and a refrigerant condition detection device according to some embodiments;

FIG. 3 illustrates a refrigerant detection device output state parameter versus set duty cycle according to some embodiments;

FIG. 4 illustrates a circuit diagram of a signal conversion circuit according to some embodiments;

FIG. 5 illustrates a state Parameter (PWM) versus measured voltage (A/D) correspondence, in accordance with some embodiments;

fig. 6 illustrates a refrigerant detection device output parameter, duty cycle, and voltage value correspondence, according to some embodiments.

Detailed Description

To make the purpose and embodiments of the present application clearer, the following will clearly and completely describe the exemplary embodiments of the present application with reference to the attached drawings in the exemplary embodiments of the present application, and it is obvious that the described exemplary embodiments are only a part of the embodiments of the present application, and not all of the embodiments.

It should be noted that the brief descriptions of the terms in the present application are only for convenience of understanding of the embodiments described below, and are not intended to limit the embodiments of the present application. These terms should be understood in their ordinary and customary meaning unless otherwise indicated.

The terms "first," "second," "third," and the like in the description and claims of this application and in the above-described drawings are used for distinguishing between similar or analogous objects or entities and not necessarily for describing a particular sequential or chronological order, unless otherwise indicated. It is to be understood that the terms so used are interchangeable under appropriate circumstances.

The terms "comprises" and "comprising," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a product or apparatus that comprises a list of elements is not necessarily limited to all elements expressly listed, but may include other elements not expressly listed or inherent to such product or apparatus.

A refrigeration apparatus according to an embodiment of the present application will be described below with reference to the accompanying drawings. Fig. 1 is a schematic diagram of a refrigerant circuit of the refrigeration apparatus of the present embodiment. The refrigeration apparatus employs a compression refrigeration cycle, and includes four main components, i.e., a compressor 101, a condenser 102 (high-temperature heat source), a throttle element 103, and an evaporator 104 (low-temperature heat source), to form a refrigerant circuit, in which a refrigerant circulates through the compressor 101, the condenser 102, the throttle element 103, and the evaporator 104 in this order.

In the following part of the present embodiment, a refrigeration apparatus will be described taking the air conditioning apparatus 100 as an example. Those skilled in the art will readily appreciate that other refrigeration apparatus not specifically described, such as heat pump systems, refrigerated cabinets, freezer cabinets, commercial array cabinets, commercial ice making equipment, domestic freezer and refrigeration chiller plants, refrigerated transport plants, and the like, that employ a compressor as the energy conditioning device and that are suitable for use in the refrigerant circuit described above are intended to be within the scope of the present invention.

In the present embodiment, the cooling and heating cycle of the air conditioner 100 includes a series of processes involving compression, condensation, expansion, and evaporation to cool or heat the indoor space.

The low-temperature and low-pressure refrigerant enters the compressor 101, and the compressor 101 compresses the refrigerant gas in a high-temperature and high-pressure state and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser 102. The condenser 102 condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process.

The throttling element 103, which is exemplified by an expansion valve, expands the liquid-phase refrigerant in a high-temperature and high-pressure state condensed in the condenser 102 into a low-pressure liquid-phase refrigerant. The evaporator 104 evaporates the refrigerant expanded in the expansion valve, and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor 101. The evaporator 104 may achieve a cooling effect by heat-exchanging with a material to be cooled using latent heat of evaporation of a refrigerant. The air conditioner 100 may adjust the temperature of the indoor space throughout the cycle.

The outdoor unit of the air conditioner 100 refers to a portion of a refrigeration cycle including the compressor 101, an outdoor heat exchanger, and an outdoor fan, the indoor unit of the air conditioner 100 refers to a portion including an indoor heat exchanger and an indoor fan, and a throttling device (such as a capillary tube or an electronic expansion valve) may be provided in the indoor unit or the outdoor unit.

An indoor heat exchanger and an outdoor heat exchanger are used as the condenser 102 or the evaporator 104. When the indoor heat exchanger is used as the condenser 102, the air conditioner 100 performs a heating mode, and when the indoor heat exchanger is used as the evaporator 104, the air conditioner 100 performs a cooling mode.

The mode of switching the indoor heat exchanger and the outdoor heat exchanger to be used as the condenser 102 or the evaporator 104 generally adopts a four-way valve, and specific reference is made to the setting of the conventional air conditioning equipment 100, which is not described herein again.

The cooling operation principle of the air conditioner 100 is as follows: the compressor 101 works to make the interior of the indoor heat exchanger (in the indoor unit, the evaporator 104 at this time) be in an ultra-low pressure state, the liquid refrigerant in the indoor heat exchanger is quickly evaporated to absorb heat, the air blown out by the indoor fan flows through the coil pipe of the indoor heat exchanger to be cooled and becomes cold air to be blown into the room, the evaporated and vaporized refrigerant is compressed by the compressor 101 and then is condensed into liquid in the high-pressure environment in the outdoor heat exchanger (in the outdoor unit, the condenser 102 at this time) to release heat, the heat is dissipated into the atmosphere through the outdoor fan, and the refrigeration effect is achieved by the circulation.

The heating operation principle of the air conditioner 100 is as follows: the gaseous refrigerant is pressurized by the compressor 101 to become a high-temperature and high-pressure gas, and the high-temperature and high-pressure gas enters the indoor heat exchanger (in this case, the condenser 102), is condensed, liquefied, releases heat to become a liquid, and heats indoor air, thereby achieving the purpose of increasing the indoor temperature. The liquid refrigerant is decompressed by the throttle device, enters the outdoor heat exchanger (in this case, the evaporator 104), evaporates, gasifies, absorbs heat, turns into gas, absorbs heat from outdoor air (the outdoor air becomes cooler), turns into a gaseous refrigerant, and enters the compressor 101 again to start the next cycle.

In some alternative embodiments of the present application, the air conditioner 100 may include a plurality of indoor units, which are operated in cooperation with the outdoor unit, such as a "one-to-many" air conditioner set.

In some alternative embodiments of the present application, the air conditioner 100 may include a plurality of outdoor units. The outdoor units may be configured to operate in groups, for example, two outdoor units may be configured as a group, and the indoor units corresponding to the outdoor units may be configured as a set. One compressor 101 or a plurality of compressors 101 may be provided for each outdoor unit, and ac power is supplied to the compressors 101 through an inverter device. When the output frequency of the inverter device changes, the rotation speed of the compressor 101 changes, and different air conditioning capacities are realized.

In some alternative embodiments of the present application, the indoor unit may adopt an independent air supply structure, for example, a wall-mounted air supply structure, a floor-mounted air supply structure, an air duct type air supply structure, or an air supply structure embedded in a ceiling, and the like.

In some optional embodiments of the present application, the indoor unit is correspondingly provided with a line controller, and the line controller is provided with an operation interface for inputting a set temperature and an operation mode, and a display interface for displaying a real-time temperature or an operation state of an air-conditioning room.

In some optional embodiments of the present application, the indoor unit is correspondingly provided with a remote controller, and the remote controller is provided with a key for inputting a set temperature and an operation mode.

In some optional embodiments of the present application, the indoor unit is correspondingly in communication connection with the mobile terminal, and the mobile terminal has an application interface, and can input a set temperature and an operation mode through the application interface and display a real-time temperature or an operation state of the air-conditioning room.

In some optional embodiments of the present application, an outdoor heat exchanger is disposed in each outdoor unit, and the refrigerant in the outdoor heat exchanger can exchange heat with an external medium, which may be water or air.

In some alternative embodiments of the present application, the number of electronic expansion valves and four-way valves as the throttling element 103 can be designed according to the functional requirements.

In some optional embodiments of the present application, the refrigerant condition detection device 200 is an apparatus using a semiconductor-type gas sensor as a detection means, and can detect refrigerants such as R32, R407C, R410A, R, R600, and the like. The gas sensor has a sensor resistance value that varies with respect to the gas concentration, the sensor resistance value decreasing as the refrigerant gas concentration increases. The refrigerant state detection device 200 has an Asynchronous Receiver/Transmitter (UART) to output a detection result. The refrigerant state detection device 200 may be installed in an outdoor unit, an indoor unit, a pipe between the outdoor unit and the indoor unit, or an air-conditioned room.

Referring to fig. 2, the indoor unit is provided with a main control board 105 connected to a refrigerant state detection device 200, and the main control board 105 is provided with a signal conversion circuit 107 and a processing chip 106.

In some alternative embodiments of the present application, the refrigerant state detection device 200 outputs the state parameter, which is a pulse width modulation signal (PWM signal) having different set duty ratios, through the asynchronous serial communication port.

For example, the state parameters with different set duty ratios respectively correspond to the refrigerant concentration in the refrigeration equipment, for example, the state parameter with a certain set duty ratio corresponds to the refrigerant concentration state far lower than a set concentration threshold (for example, 1/4 of the combustion limit concentration), namely, the safe state; the other state parameter of the set duty ratio corresponds to the refrigerant concentration state lower than the set concentration threshold value, namely the state needing further monitoring; the state parameter of the other set duty ratio corresponds to the refrigerant concentration state close to the set concentration threshold value, namely the dangerous state close to the threshold value; there is also a set of state parameters for the set duty cycle corresponding to a state of refrigerant concentration that is beyond the sensing range, i.e., a high risk state.

In some alternative embodiments of the present application, the refrigerant state detection device 200 may also output state parameters with different set duty cycles to characterize the hardware state of the refrigerant state detection device 200. Illustratively, for example, one state parameter of a set duty cycle corresponds to a hardware state at which the sensor life has expired, and another state parameter of a set duty cycle corresponds to an abnormal hardware state of the sensor.

In some alternative embodiments of the present application, the refrigerant state detection device 200 may also output state parameters with different set duty cycles to characterize the power state of the refrigerant state detection device 200. Illustratively, a state parameter such as a certain set duty cycle corresponds to a power state of the sensor with an abnormal power supply.

In some optional embodiments of the present application, the refrigerant state detection device 200 may also optionally output a state parameter with different set duty cycles to represent one of the refrigerant states of different refrigeration equipment, the power states of the refrigerant state detection device 200, and the hardware states of the refrigerant state detection device 200.

Fig. 3 is a corresponding relationship between the output state parameter of the refrigerant detection device and the set duty ratio. The refrigerant detection device outputs PWM signals with corresponding duty ratios according to different actual states, and the PWM duty ratios are PWM outputs corresponding to each output parameter of the refrigerant detection device.

As shown in fig. 4, the signal conversion circuit 107 has an input terminal, an optical coupler IC1, a first capacitor C1, a first resistor R1, a second resistor R2, a third resistor R3, and an output terminal.

The input terminal of the signal conversion circuit 107 is configured to be connected to the refrigerant state detection device 200, and in particular, to an asynchronous serial communication port (UART) of the refrigerant state detection device 200. The optical coupler IC1 realizes signal isolation, shields interference and improves the reliability of signal acquisition. A first pin of the primary side of the optocoupler IC1, i.e., the anode of the light emitting diode, is connected to the input terminal via a first resistor R1, a second pin of the primary side, i.e., the cathode of the light emitting diode, is grounded, and a secondary side, i.e., the collector of the phototransistor is connected to the power supply VCC via a second resistor R2.

The second pin of the secondary side of the optical coupler IC1, namely the emitter of the phototriode, is connected to the anode of the first capacitor C1, and the cathode of the first capacitor C1 is grounded. One end of the third resistor R3 is connected to the second pin on the secondary side of the optocoupler IC1, and the cathode is grounded.

The output end of the signal conversion circuit 107 is connected to the second pin on the secondary side of the optocoupler IC1, i.e. led out from one end of the third resistor R3, and the other end is connected to the analog-to-digital converter of the processing chip 106.

The optical coupler IC1 realizes signal isolation, shields interference and improves the reliability of signal acquisition. Due to the filtering effect of the first capacitor C1 and the third resistor R3, the positive period of the PWM signal charges the first capacitor C1, and the negative period discharges the first capacitor C1 to the outside. In this way, the first capacitor C1 is charged and discharged according to the PWM signal, so that the voltage of the first capacitor C1 is close to the equivalent dc signal of the PWM signal and is kept relatively stable. The output terminal is configured to output a measured voltage, the measured voltage being positively correlated with the set duty cycle.

In this way, the signal conversion circuit 107 converts the pulse width modulation signal (PWM signal) output from the refrigerant state detection device 200 into a voltage value that can be sampled by the analog-to-digital sensor. Because the state parameters have different set duty ratios, the actually measured voltage also has voltage values corresponding to the set duty ratios one to one.

In some optional embodiments of the present application, the type selection of the first resistor R1, the second resistor R2, the third resistor R3, and the first capacitor C1 needs to consider the ranges of the PWM period, the duty ratio, and the sampling voltage value, and control the charging and discharging time of the first capacitor C1, so as to ensure that the circuit operates in a stable state. And selecting corresponding resistance-capacitance parameters according to the set PWM duty ratio to enable the sampling voltage value of the analog-digital converter to be within the range of 0V-5V.

FIG. 5 is a representation of a set of corresponding relationships between the state Parameters (PWM) and the measured voltage (A/D).

When the power supply voltage VCC is 5V, the voltage full scale is 5V. Assuming that the set duty ratio of a certain state parameter is 50%, the theoretical value of the measured voltage is 2.5V (5V × 50%), that is, the measured voltage output by the output terminal of the signal conversion circuit 107 is 2.5V.

The resistor has F precision, and the influence of the precision error on the AD sampling value can be ignored because the charging and discharging current of the electrolytic capacitor is very small. As can be seen from the measured ripple voltage, the sampling accuracy is + -0.1V.

Different duty ratios correspond to different voltage values, and the correspondence is shown in table 6. The processing chip 10 determines the current state of the refrigerant state detection device 200 based on the sampled voltage value, and sends a prompt through an external device (e.g., a buzzer, a display panel, a mobile terminal, a line controller, a remote controller, etc.) to respond in time.

The illustrative discussions above are not intended to be exhaustive or to limit the embodiments to the precise forms disclosed above. Many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles and the practical application, to thereby enable others skilled in the art to best utilize the embodiments and various embodiments with various modifications as are suited to the particular use contemplated.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and these modifications or substitutions do not depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A signal conversion circuit, comprising:

an input end;

the first pin of the primary side of the optical coupler is connected with the input end through a first resistor, and the second pin of the primary side of the optical coupler is grounded; the secondary side first pin is connected with a power supply through a second resistor;

the positive electrode of the first capacitor is connected with the second pin at the secondary side of the optical coupler, and the negative electrode of the first capacitor is grounded;

one end of the third resistor is connected with a second pin on the secondary side of the optical coupler, and the negative electrode of the third resistor is grounded;

and one end of the output end is connected with a second pin on the secondary side of the optical coupler, and the other end of the output end is connected with the analog-to-digital converter.

2. The signal conversion circuit of claim 1, wherein the input is configured to connect to a refrigerant condition detection device; the refrigerant detection device outputs a pulse width modulation signal.

3. The signal conversion circuit of claim 2, wherein a duty cycle of the pulse width modulated signal corresponds to an actual state of the refrigerant detection device.

4. The signal conversion circuit of claim 3, wherein the duty cycles correspond to different refrigerant concentration states.

5. The signal conversion circuit according to claim 3, wherein the duty ratio corresponds to a power state of the refrigerant state detection device.

6. The signal conversion circuit of claim 3, wherein the duty cycle corresponds to a hardware state of the refrigerant state detection device.

7. The signal conversion circuit according to any one of claims 4 to 6, wherein the output parameter of the output terminal is a voltage value, and the voltage value is positively correlated with the duty ratio.

8. The signal conversion circuit according to claim 4, wherein a semiconductor-type gas sensor for detecting a refrigerant concentration is provided in the refrigerant detection device.

9. Refrigeration equipment, characterized by comprising a main control board, wherein the main control board is provided with a signal conversion circuit according to any one of claims 1 to 8.

10. The refrigeration equipment as claimed in claim 9, wherein the main control board is further provided with a processing chip, and the processing chip is provided with an analog-to-digital converter.