JP4317878B2 - Air conditioner and method for judging refrigerant amount - Google Patents

Description

  The present invention relates to an air conditioner and a method for determining the amount of refrigerant that can determine the suitability of the amount of refrigerant charged in an air conditioner, and in particular, whether an appropriate amount of refrigerant is sealed after the air conditioner is installed. Alternatively, it is possible to determine whether or not there is a refrigerant leak.

  Among the air conditioners that have outdoor units and indoor units, especially in the case of a separate type air conditioner that connects multiple indoor units, the installation conditions for the indoor units and outdoor units are diverse. It is difficult to ship all of them filled in the outdoor unit. For this reason, it is necessary to fill the outdoor unit with a predetermined amount of refrigerant, and additionally enclose the refrigerant necessary for local construction.

  On the other hand, like the thing of patent document 1, the subcooling heat exchanger provided with the subflow part between the refrigerant | coolant amount regulator (liquid receiver) of the outdoor unit and the indoor unit at the time of the test run after field construction The main flow part is arranged, and the suitability of the refrigerant amount in the air conditioner (refrigeration cycle) is determined based on the refrigerant supercooling degree on the outlet side of the main flow part.

JP 2005-114184 A

  In the thing of the said patent document 1, it is necessary to perform air_conditionaing | cooling operation | movement of all the indoor units connected to the air conditioner by implementing refrigerant | coolant amount determination driving | operation at the time of trial operation, and to perform refrigerant | coolant amount determination in the state where the state of the refrigerating cycle was stabilized. There is. For this reason, it is difficult to determine the refrigerant amount when the refrigerant in the refrigerant circuit leaks to the outside after completing the test operation and starting the normal operation. In particular, in an air conditioner provided with a plurality of indoor units that can be started and stopped individually, the operation state differs depending on each indoor unit, which causes a decrease in refrigerant amount determination accuracy.

  An object of the present invention is to obtain an air conditioner and a refrigerant amount determination method for the air conditioner that can detect when refrigerant in the air conditioner leaks outside after starting normal operation.

  Another object of the present invention is to make it possible to detect a refrigerant leak as soon as possible after starting normal operation.

  Still another object of the present invention is to enable early detection of the refrigerant amount determination after the start of normal operation and to enable accurate refrigerant amount determination.

  In order to solve the above problems, the present invention provides an outdoor unit including a compressor, a four-way valve, an outdoor heat exchanger, an outdoor expansion device, and an outdoor blower, and an indoor unit including an indoor expansion device, an indoor heat exchanger, and an indoor blower. In an air conditioner connected by a liquid connection pipe and a gas connection pipe, means for obtaining a coefficient χ based on the output amount to the indoor expansion device or the outdoor expansion device and the output amount to the compressor, An outside air temperature detecting means for detecting a temperature, and a means for determining a refrigerant amount based on the obtained coefficient χ and the detected outside air temperature.

Where the coefficient χ is
The coefficient χ is preferably obtained from the output amount to the indoor or outdoor expansion device / output amount to the compressor. As the output amount to the indoor or outdoor expansion device, the opening degree of the expansion device or the number of pulses (in the case of an electric expansion valve) may be used, and the output amount to the compressor may be the rotational speed of the compressor ( It is preferable to use the number of compressors to be driven (in the case of a rotational speed control compressor) and the number of compressors to be driven (in the case of having a plurality of compressors).

  The means for determining the amount of refrigerant calculates and stores in advance the value of the coefficient χ with respect to the outside air temperature and the upper limit value of the allowable range of the coefficient χ by operating the air conditioner in the state of the appropriate amount of refrigerant. The refrigerant amount may be determined based on the coefficient χ obtained during normal operation and the outside air temperature.

In obtaining the coefficient χ, it is preferable to use the output amount to the indoor expansion device during the cooling operation and the output amount to the outdoor expansion device during the heating operation.
Furthermore, when the refrigerant amount is determined by adding the pipe length from the outdoor unit to the indoor unit or the height difference data between the outdoor unit and the indoor unit, the refrigerant amount can be accurately determined.
When it is determined that the refrigerant amount has decreased, it is preferable to display that there is a refrigerant leak and to automatically stop the operation.

Further, a refrigerant amount determination operation mode for forcibly operating all indoor units to determine the refrigerant amount is provided, and when it is determined that the refrigerant amount has decreased during normal operation, the refrigerant amount determination operation is automatically performed. It is more preferable to carry out the mode so as to accurately determine whether or not the refrigerant amount is appropriate.
The refrigerant amount determination information may be displayed on a service department terminal via the Internet.

Another feature of the present invention includes an outdoor unit including a compressor, a four-way valve, an outdoor heat exchanger, an outdoor expansion device, and an outdoor fan, and an indoor unit including an indoor expansion device, an indoor heat exchanger, and an indoor fan. In the air conditioner connected with the liquid connection pipe and the gas connection pipe, the output amount to the indoor expansion device, and the coefficient χ based on the output amount to the compressor,
Coefficient χ = arithmetic means determined by the output amount to the indoor expansion device / output amount to the compressor, the outside air temperature detecting means for detecting the outside air temperature, the refrigerant by the obtained coefficient χ and the detected outside air temperature And a means for determining the amount.

  Still another feature of the present invention includes an outdoor unit including a compressor, a four-way valve, an outdoor heat exchanger, an outdoor expansion device, and an outdoor fan, and an indoor unit including an indoor expansion device, an indoor heat exchanger, and an indoor fan. In the air conditioner connected by the liquid connection pipe and the gas connection pipe, the ratio of the output amount to the indoor expansion device or the outdoor expansion device and the output amount to the compressor in a state where an appropriate refrigerant is sealed. The relationship between the related value and the outside air temperature was obtained in advance, and related to the ratio between the output amount to the indoor expansion device or the outdoor expansion device and the output amount to the compressor obtained during the operation of the air conditioner. The value is in the refrigerant amount determination method of the air conditioner for determining the refrigerant amount by comparing the value with the value obtained in advance with respect to the outside air temperature at that time.

Here, the value is a value obtained as the following coefficient χ, that is, the coefficient χ = the output amount to the indoor or outdoor expansion device / the output amount to the compressor. The output amount to the outdoor expansion device is preferably used during heating operation.

  According to the present invention, after normal operation is started, when the refrigerant in the air conditioner leaks to the outside, this can be detected early or quickly.

  In addition, the refrigerant amount determination after the start of normal operation can be detected at an early stage, and if it is determined that the refrigerant amount has decreased, the refrigerant amount determination operation mode is further implemented. There is an effect that can be performed well.

  Specific embodiments of the present invention will be described below with reference to the drawings.

  In FIG. 1, an outdoor unit 22 includes a variable capacity compressor 1 and a fixed capacity compressor 2 that are controlled by varying an operating frequency with an inverter. The compressors 1 and 2 are shown in the figure. These are arranged in parallel and connected to the four-way valve 3. The four-way valve 3 is piped to the outdoor heat exchanger 4 side and the gas blocking valve 11 side. The outdoor heat exchanger 4 is connected to a refrigerant amount regulator (liquid receiver) 6, a supercooling heat exchanger 7, and a liquid blocking valve 8 through an outdoor expansion device 5.

  As shown in the figure, a plurality of indoor units 23 are connected in parallel to the outdoor unit 22 via a liquid pipe 30 and a gas pipe 31, and each indoor unit 23 includes an indoor expansion device 9 and an indoor heat exchanger 10. And an indoor blower (not shown).

The discharge side piping of the compressors 1 and 2 of the outdoor unit 22 has a discharge pressure sensor 13 for detecting the pressure of the refrigerant gas discharged from the compressor, and a discharge temperature sensor 15 for detecting the temperature of the refrigerant gas. A temperature sensor 17 for detecting the temperature of the liquid pipe (liquid refrigerant) is provided between the supercooling heat exchanger 7 and the liquid blocking valve 8. Further, the indoor unit 23 includes a suction temperature sensor (indoor temperature thermistor) 32 that detects the temperature of air flowing into the indoor heat exchanger 10 and a blowout temperature sensor (outdoor temperature) that detects the temperature of air blown from the indoor heat exchanger 10. A gas temperature sensor 19 in the gas pipe connected to the indoor heat exchanger 10, and a liquid temperature sensor 18 in the liquid pipe between the indoor expansion device 9 and the liquid blocking valve 8. Yes.
Reference numerals 16, 18, and 19 denote temperature sensors, and reference numeral 21 denotes an arithmetic unit that controls the air conditioner.

Next, the case where the air conditioner having the above configuration is subjected to normal cooling operation will be described.
In the cooling operation, the refrigerant flows in the direction of the solid arrow in FIG. 1, and the gas refrigerant discharged from the compressors 1 and 2 passes through the four-way valve 3 and flows into the outdoor heat exchanger 4 to condense. The condensed liquid refrigerant enters the refrigerant quantity regulator 6, and the liquid refrigerant derived from the refrigerant quantity regulator 6 is supercooled by the supercooling heat exchanger 7 and is connected to the outdoor unit 22 and the indoor unit 23. It flows into the indoor expansion device 9 through the pipe 30. The indoor expansion device 9 is an expansion device that can be set to an arbitrary throttle amount. The refrigerant decompressed by the indoor expansion device 9 is sent to the indoor heat exchanger 10 to evaporate, thereby cooling the indoor air. The evaporated refrigerant returns to the suction side of the compressors 1 and 2 through the gas pipe 31.

  The case where the said air conditioner carries out normal heating operation is demonstrated. In the heating operation, the refrigerant flows in the direction of the dotted arrow in FIG. 1 by switching the four-way valve 3, and the refrigerant discharged from the compressors 1 and 2 passes through the four-way valve 3 and the gas blocking valve 11 to exchange the heat in the room. The room air is heated by heat dissipation and condensation in the vessel 10 to perform heating. The condensed liquid refrigerant flows into the outdoor unit 22 through the liquid pipe 30 and enters the refrigerant amount adjuster 6. The liquid refrigerant is led out from the refrigerant amount adjuster 6 and enters the outdoor expansion device 5. The outdoor expansion device 5 is also an expansion device that can be set to an arbitrary throttle amount, and the refrigerant depressurized by the outdoor expansion device 5 flows into the outdoor heat exchanger 4 and evaporates to become a state with a high degree of cuteness. And return to the compressors 1 and 2.

  In addition, the present embodiment includes a refrigerant amount determination operation mode that is performed separately from the cooling operation and the heating operation. Hereinafter, the refrigerant amount determination operation mode will be described with reference to FIG. In the refrigerant quantity determination operation mode, all the indoor units 23 connected to the air conditioner are operated for cooling (flowing refrigerant as indicated by solid line arrows). Control is performed so that the degree of superheat of the discharge gas becomes equal to or higher than the set value by the indoor expansion valve 9 until the changes in the discharge gas temperature and discharge gas pressure of the compressors 1 and 2 become small during the cooling operation, that is, until the refrigeration cycle is stabilized . Detected by the saturation temperature calculated from the discharge pressure sensor 13 and the temperature sensor 17 at the outlet of the supercooling heat exchanger 7 when the discharge gas superheat degree is equal to or higher than the set value (state where the compressor discharge heating degree is stabilized). If the value of the degree of supercooling obtained from the temperature is within a preset range, it is determined that the amount of refrigerant is appropriate.

  The refrigerant amount determination operation mode described above is for determining the suitability of the amount of refrigerant enclosed by cooling all the indoor units 23 connected to the air conditioner. Normal air-conditioning operation must be temporarily stopped. In the present embodiment, it is configured so that it is possible to determine whether or not the refrigerant amount is appropriate (or to determine whether or not there is a refrigerant leak) even if normal operation is continued. Hereinafter, refrigerant amount determination during normal operation will be described with reference to FIGS.

  First, the refrigerant amount determination during the normal cooling operation will be described. In the cooling operation, the throttle amount of the indoor expansion device is adjusted so that the degree of superheat of the discharge gas falls within a preset range. When the discharge gas superheat degree falls within the set temperature range, and the fluctuations in the discharge pressure and discharge temperature decrease, the output amount to the indoor expansion device 9 (in the case of an expansion valve opening or an electric expansion valve, the number of pulses, etc.) If there are multiple indoor units, this is the total opening of the indoor expansion valves) and a coefficient based on the output to the compressor (frequency, etc. in the case of a rotational speed control compressor) For example, χ is obtained by the following equation (1).

Coefficient χ = Output amount to the indoor expansion device / Output amount to the compressor (1)
In addition, the outdoor temperature thermistor 24 detects the ambient temperature (outside temperature) of the outdoor unit 22. When the coefficient χ becomes equal to or greater than a preset value from the outside air temperature, it is determined that the refrigerant is insufficient. An example for making this determination is shown in FIG. In advance, the air conditioner is operated in a state of an appropriate refrigerant amount, and the value of the coefficient χ with respect to the outside air temperature is obtained as shown by the solid line in FIG. Further, the upper limit of the allowable range of the coefficient χ with respect to the outside air temperature is obtained as indicated by the dotted line in FIG. Next, the coefficient χ based on the above equation (1) and the outside air temperature are obtained during normal operation, and if the obtained coefficient χ is in the refrigerant shortage region of FIG. If there is, it is determined that the amount of refrigerant is appropriate. In addition, when it determines with a refrigerant | coolant shortage, it means that the refrigerant | coolant has leaked from the time of enclosing a refrigerant | coolant in an air conditioner.

  In the above example, if the suction temperature (room temperature) into the indoor unit 23 is also detected by the room temperature thermistor 32 and the relationship between the coefficient χ, the outside air temperature and the room temperature is obtained, the accuracy is further increased. The refrigerant amount can be determined. The output amount to the compressor is a frequency in the case of a rotational speed control compressor, but in the case of providing one or a plurality of fixed capacity compressors, the number of compressors can be operated. That is, a parameter related to the total discharge flow rate from all the compressors may be used.

  Next, refrigerant amount determination during normal heating operation will be described. In the heating operation, the throttle amount of the outdoor expansion device 5 is adjusted so that the discharge gas superheat degree is in a preset range. When the discharge gas superheat degree falls within the set temperature range and the fluctuations in the discharge pressure and the discharge temperature decrease, the coefficient χ based on the output amount to the outdoor expansion device 5 and the output amount to the compressor is expressed by the following equation ( Obtained by 2).

Coefficient χ = Output amount to outdoor expansion device / Output amount to compressor (2)
In addition, the outdoor temperature thermistor 24 detects the ambient temperature (outside temperature) of the outdoor unit 22. Further, as in the case of the cooling operation, the air conditioner is operated in the state of the appropriate refrigerant amount, and the value of the coefficient χ with respect to the outside air temperature is obtained in advance as shown in FIG. 4 (the solid line is the optimum value, the dotted line) Is the upper limit value of the allowable range), and the suitability of the refrigerant amount is determined.
FIG. 2 is a flowchart summarizing a series of operations for determining whether or not the refrigerant amount is appropriate according to this embodiment.

  In the above, only the outside air temperature (and the room temperature) was used as the judgment condition. However, the output to the expansion device changed depending on the construction conditions of the air conditioner (pipe length / height difference between the outdoor unit and the indoor unit). Therefore, if the construction condition of the air conditioner is added as a determination condition, the determination accuracy can be further improved. Further, a memory may be provided in the arithmetic unit 21 (see FIG. 1) that controls the air conditioner, and a change in the coefficient χ may be recorded to add information on a time change in the coefficient χ to the determination.

  In the above-described refrigerant amount determination during normal operation, when it is determined that the refrigerant is insufficient, it is displayed on a remote control switch (not shown) or the like, the refrigerant leak is reported to the user of the air conditioner, and the air conditioner It is better to stop driving. Moreover, you may make it report the refrigerant | coolant leak to a user by generating a warning sound with an alarm device. Furthermore, by connecting the air conditioner to the Internet or the like, information on refrigerant leakage can be displayed on the terminal of the service department, and a service person can be dispatched quickly.

  Further, in the refrigerant amount determination during the normal operation described above, when it is determined that the refrigerant is insufficient, the refrigerant amount determination operation mode described above is automatically and forcibly implemented and connected to the air conditioner. If the refrigerant amount is determined by forcibly cooling all the indoor units, the accuracy of the refrigerant amount determination can be further improved. In addition, instead of automatically performing the refrigerant amount determination operation mode in this case, a service person or the like operates a switch or the like installed in the outdoor unit, or connects a personal computer to the air conditioner, Switching from the personal computer to the refrigerant amount determination operation mode may be performed. Furthermore, the air conditioner may be connected to a network computer or a centralized controller, and the refrigerant amount determination operation mode may be switched from these.

  According to this embodiment, during operation of the air conditioner, the amount of refrigerant in the refrigerant circuit (connection pipe or air conditioner) is detected by detecting the operation state amount (expansion device output amount, compressor output amount, etc.). This can be determined at an early stage when the value decreases. If it is determined that the amount of refrigerant has decreased, a message indicating that the refrigerant is leaking is displayed, and the operation is stopped to quickly notify the refrigerant leakage and to take further measures to prevent further refrigerant leakage. be able to. When it is determined that the refrigerant amount has decreased, it is possible to determine the suitability of the refrigerant amount with higher accuracy by further performing the refrigerant amount determination operation mode.

The refrigeration cycle block diagram which shows the Example of the air conditioner of this invention. The flowchart explaining the procedure of refrigerant | coolant amount determination during normal driving | operation. The diagram which shows the relationship between the external temperature for performing refrigerant | coolant amount determination in normal cooling operation, and the coefficient (chi). The diagram which shows the relationship between the external temperature for performing refrigerant | coolant amount determination in normal heating operation, and the coefficient (chi).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Variable capacity type compressor, 2 ... Fixed capacity type compressor, 3 ... Four-way valve, 4 ... Outdoor heat exchanger, 5 ... Outdoor expansion device, 6 ... Refrigerant amount regulator (liquid receiver), 7 ... Supercooling Heat exchanger, 8 ... Liquid blocking valve, 9 ... Indoor expansion device (electric expansion valve), 10 ... Indoor heat exchanger, 11 ... Gas blocking valve, 12 ... Accumulator, 13 ... Discharge pressure sensor, 14 ... Suction pressure sensor, DESCRIPTION OF SYMBOLS 15 ... Discharge temperature sensor, 16-19 ... Temperature sensor, 20 ... Outdoor fan, 21 ... Arithmetic unit, 22 ... Outdoor unit, 23 ... Indoor unit, 24 ... Outdoor temperature thermistor, 30 ... Liquid piping, 31 ... Gas piping, 32 ... Indoor temperature thermistor.

Claims (11)

Compressor, four-way valve, outdoor heat exchanger, outdoor expansion device, outdoor unit provided with outdoor blower, and indoor unit provided with indoor expansion device, indoor heat exchanger, indoor blower, liquid connection pipe and gas connection pipe In the air conditioner connected with
Means for obtaining a coefficient χ based on the output amount to the indoor expansion device or the outdoor expansion device and the output amount to the compressor;
Outside temperature detecting means for detecting outside temperature;
An air conditioner comprising: means for determining a refrigerant amount based on the obtained coefficient χ and the detected outside air temperature. In claim 1, the coefficient χ is
An air conditioner characterized in that the coefficient χ = the output amount to the indoor or outdoor expansion device / the output amount to the compressor.   The means for determining the amount of refrigerant according to claim 2, wherein the air conditioner is operated in advance in a state of an appropriate amount of refrigerant, and the value of the coefficient χ with respect to the outside air temperature and the upper limit value of the allowable range of the coefficient χ are obtained and stored. The air conditioner is characterized in that the refrigerant amount is determined based on the coefficient χ obtained during normal operation and the outside air temperature.   The air conditioner according to claim 2, wherein an output amount to the indoor expansion device is used during cooling operation, and an output amount to the outdoor expansion device is used during heating operation.   2. The air conditioner according to claim 1, wherein the refrigerant amount is determined by adding a pipe length from an outdoor unit to the indoor unit or height difference data between the outdoor unit and the indoor unit.   2. The air conditioner according to claim 1, wherein when it is determined that the refrigerant amount has decreased, an indication that there is a refrigerant leak is displayed and the operation is automatically stopped.   2. The refrigerant amount determination mode according to claim 1, further comprising: a refrigerant amount determination operation mode for determining the refrigerant amount by forcibly operating all the indoor units, and automatically determining the refrigerant amount when it is determined that the refrigerant amount has decreased during normal operation. An air conditioner characterized by carrying out an operation mode to determine whether the refrigerant amount is appropriate.   2. The air conditioner according to claim 1, wherein the refrigerant amount determination information is displayed on a terminal of a service department via the Internet. Compressor, four-way valve, outdoor heat exchanger, outdoor expansion device, outdoor unit provided with outdoor blower, and indoor unit provided with indoor expansion device, indoor heat exchanger, indoor blower, liquid connection pipe and gas connection pipe In the air conditioner connected with
A coefficient χ based on the output amount to the indoor expansion device and the output amount to the compressor,
Coefficient χ = calculation means for obtaining by the output amount to the indoor expansion device / output amount to the compressor;
Outside temperature detecting means for detecting outside temperature;
An air conditioner comprising: means for determining a refrigerant amount from the obtained coefficient χ and the detected outside air temperature. Compressor, four-way valve, outdoor heat exchanger, outdoor expansion device, outdoor unit provided with outdoor blower, and indoor unit provided with indoor expansion device, indoor heat exchanger, indoor blower, liquid connection pipe and gas connection pipe In the air conditioner connected with
A value related to the ratio between the output amount to the indoor expansion device or the outdoor expansion device and the output amount to the compressor in a state where an appropriate refrigerant is sealed, and the relationship between the outdoor air temperature and
The value related to the ratio of the output amount to the indoor expansion device or the outdoor expansion device and the output amount to the compressor obtained during the operation of the air conditioner was previously obtained with respect to the outdoor temperature at that time. A refrigerant amount determination method for an air conditioner, wherein the refrigerant amount is determined by comparing with a value. In Claim 10, the said value is the value calculated | required as the following coefficient χ, ie, coefficient χ = output amount to the indoor or outdoor expansion device / output amount to the compressor. A refrigerant amount determination method for an air conditioner, characterized in that an output amount to an outdoor expansion device is used during heating operation using an output amount to the device.

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