JP3481274B2 - Separate type air conditioner - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separation type air conditioner.

[0002]

2. Description of the Related Art FIG. 5 shows, for example, Japanese Patent Publication No. 53-13249.
FIG. 7 is a refrigerant circuit diagram of a conventional separation type air conditioner disclosed in Japanese Patent Publication No. During cooling, compressor 1, discharge pipe 5, four-way valve 16,
The outdoor heat exchanger 2, the check valve 14, the strainer 15, the pressure reducing device 4, the check valve 11, the indoor heat exchanger 3, the four-way valve 16, the suction pipe 6, and the compressor 1 are connected in this order, and when heating, compression is performed. Machine 1,
Discharge pipe 5, four-way valve 16, indoor heat exchanger 3, check valve 1
2, the strainer 15, the pressure reducing device 4, the check valve 13, the outdoor heat exchanger 2, the four-way valve 16, the suction pipe 6, the compressor 1 are connected in this order, and after the strainer 15 and after the pressure reducing device 4,
It has a bypass circuit in which the solenoid valve 8, the accumulator 9, the capillary tube 7, and the solenoid valve 10 are connected in this order.

Next, the operation will be described. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 enters the four-way switching valve 16 through the discharge pipe 5. During the cooling operation, the four-way switching valve 16 enters the outdoor heat exchanger 2 (acting as a condenser) to be cooled and condensed and liquefied, and then passes through the check valve 14 and the strainer 15 to reach the decompression device 4. After being decompressed by the decompression device 4 to become a wet refrigerant, it is heated and evaporated in the indoor heat exchanger 3 (acting as an evaporator) through the check valve 11 to become a superheated gas refrigerant, which passes through the four-way switching valve 16 and the suction pipe 6. After that, it returns to the compressor 1. Next, during the heating operation, the four-way switching valve 16 is switched and the high-temperature high-pressure gas refrigerant discharged from the compressor 1 passes through the discharge pipe 5 through the four-way switching valve 16 as shown by a dotted arrow, and then the cycle opposite to that during cooling is completed. The heat enters the heat exchanger 3 (acting as a condenser), is cooled, condensed, and reaches the check valve 12, the strainer 15, and the pressure reducing device 4. After being decompressed by the decompression device 4 to become wet refrigerant, it passes through the check valve 13 and is heated and evaporated by the outdoor heat exchanger 2 (acting as an evaporator) to become superheated gas refrigerant and passes through the four-way switching valve 15 and suction pipe 6
After that, the compressor 1 is returned to. In addition to such a standard refrigeration cycle, a bypass consisting of a solenoid valve 8, an accumulator 9, a capillary tube 7 and a solenoid valve 10 is added.
The check valves 11, 12, 13, and 14 are provided between a pipe line that serves as a high-pressure liquefied refrigerant during cooling and heating operations and a pipe line that serves as a low-pressure wet refrigerant during both cooling and heating operations. . When the high-pressure side pressure exceeds a certain pressure during the cooling operation or the heating operation, the high-pressure side solenoid valve 8 is opened and the low-pressure side solenoid valve 10 is closed by the action of the pressure switch or the like.
As a result, the refrigerant liquid is rapidly introduced into the accumulator 9 from the high pressure side, the amount of refrigerant in the refrigeration cycle decreases, and the pressure on the high pressure side decreases. Next, when the pressure on the high-pressure side drops to a predetermined value, the high-pressure side solenoid valve 8 is closed and the low-pressure side solenoid valve 10 is opened conversely, and the refrigerant accumulated in the accumulator 9 returns to the refrigeration cycle again and becomes a normal refrigerant. It becomes the amount. It should be noted that when the refrigerant liquid in the accumulator 9 is returned to the low pressure side, the capillary tube 7 is provided after the accumulator 9 so that the refrigerant liquid is temporarily returned to a capacity higher than that of the evaporator and liquid back does not occur. ing.

[0004]

The refrigerant circuit of the conventional separation type air conditioner as described above has two solenoid valves and four check valves.
There is a problem that it is structurally complicated and expensive because it requires one piece, one capillary tube, and one accumulator. Further, since the discharge temperature protection control is not performed, there is a problem that the compressor is damaged due to the excessive rise of the discharge temperature when the refrigerant accumulates in the accumulator and the refrigerant circulation amount tends to be insufficient. Furthermore, when starting up the compressor, the operation is not particularly conscious of the start up, but normally, liquid back is liable to occur at the time of starting up, so a large amount of refrigerating machine oil in the compressor is taken out of the compressor and the shaft is burned. There was a problem that led to.

The present invention has been made in order to solve the above problems, and an object thereof is to obtain a separation type air conditioner capable of taking measures against a high pressure rise at low cost.

Another object of the present invention is to obtain a separation type air conditioner capable of suppressing an excessive rise in discharge temperature.

Further, refrigerating machine oil is not taken out of the compressor when the compressor is started. It is an object of the present invention to obtain a separation type air conditioner that can prevent damage to a compressor.

[0008]

A separate type air conditioner according to a first aspect of the present invention is an air conditioner that uses a refrigeration cycle in which a compressor, a four-way valve, an outdoor heat exchanger, a pressure reducing device, and an indoor heat exchanger are sequentially connected. In the separation type air conditioner for performing the discharge pipe temperature sensor provided on the discharge side of the compressor, the suction pipe temperature sensor provided on the suction side of the compressor, the outdoor heat exchanger and the decompression device. And an intake temperature sensor provided in a circuit that artificially generates an evaporation temperature, and limits the upper limit operating frequency of the compressor until the discharge pipe temperature exceeds a predetermined value. Means and
When it is determined that the separation type air conditioner is in operation,
Determine the target compressor operating frequency and target discharge temperature, and
The discharge temperature detected by the discharge pipe temperature sensor is the target.
If the discharge temperature is lower than
Discharge detected by the discharge pipe temperature sensor with a limited value
If the temperature is higher than the target discharge temperature, the suction pipe
With the output of the temperature sensor and the evaporation temperature sensor,
Detects perheat and becomes the target superheat
And controlling the decompression device .

[0009] according to claim 2 separate type air conditioner, according to claim 1
In the separation-type air conditioner described, a compressor, a four-way valve, an outdoor heat exchanger, a decompressor, and a separation-type air conditioner that performs cooling and heating operation using a refrigeration cycle in which an indoor heat exchanger is sequentially connected, When the high pressure switch provided on the discharge side of the machine is operated, the operating frequency of the compressor is lowered and the decompression device is opened.

The separate type air conditioner of claim 3 is the same as that of claim 1.
In the separation type air conditioner described, a compressor, a four-way valve, an outdoor heat exchanger, a decompression device, and a separation type air conditioner that performs cooling and heating operation using a refrigeration cycle in which an indoor heat exchanger is sequentially connected, When the value of the pipe temperature sensor provided in the heat exchanger exceeds a predetermined value, the operating frequency of the compressor is lowered and the decompression device is opened.

A separate type air conditioner according to a fourth aspect is the first aspect.
In the separation-type air conditioner described, a compressor, a four-way valve, an outdoor heat exchanger, a decompressor, and a separation-type air conditioner that performs cooling and heating operation using a refrigeration cycle in which an indoor heat exchanger is sequentially connected, When the value of the discharge pipe temperature sensor provided on the discharge side of the machine exceeds a predetermined value, the operating frequency of the compressor is lowered and the decompression device is opened.

[0012]

In the separation type air conditioner according to claim 1, the upper limit of the compressor operating frequency is limited until the discharge temperature exceeds a predetermined value, and the operating frequency of the compressor is increased after the discharge temperature exceeds the predetermined value. Prevents refrigeration oil from being taken out of the compressor.

In the separation type air conditioner of claim 2, the discharge temperature is
Limits the upper limit of compressor operating frequency until exceeds the specified value
However, after the discharge temperature exceeds the specified value, the operating frequency of the compressor
Lifting the refrigerating machine oil from the compressor
In addition to the prevention, when the high pressure switch detects the high pressure excessive rise and the protection of the compressor is required, the pressure reducing means can be opened to reduce the operating frequency of the compressor to reduce the high pressure side pressure.

In the separation type air conditioner of claim 3, the discharge temperature is
Limits the upper limit of compressor operating frequency until exceeds the specified value
However, after the discharge temperature exceeds the specified value, the operating frequency of the compressor
Lifting the refrigerating machine oil from the compressor
In addition to preventing, when the indoor pipe temperature sensor detects an excessive rise in high pressure and the protection of the compressor is required, the pressure reducing means can be opened to reduce the operating frequency of the compressor to reduce the pressure on the high pressure side.

According to another aspect of the separation type air conditioner, the discharge temperature is
Limits the upper limit of compressor operating frequency until exceeds the specified value
However, after the discharge temperature exceeds the specified value, the operating frequency of the compressor
Lifting the refrigerating machine oil from the compressor
In addition to the prevention, when the discharge temperature rises and the compressor needs to be protected, the pressure reducing means can be opened to lower the operating frequency of the compressor to lower the high pressure side pressure.

[0016]

【Example】

Example 1. The first embodiment of the present invention will be described below. FIG. 1 shows a refrigeration cycle of the separation type air conditioner of this embodiment. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 enters the four-way switching valve 16 through the discharge pipe 5.
During the cooling operation, as shown by the solid line, the four-way switching valve 16 enters the outdoor heat exchanger 2 (acting as a condenser) to be cooled and condensed and liquefied before reaching the electronic expansion valve 18. After being decompressed by the electronic expansion valve 18 to become moist steam, it is heated and evaporated in the indoor heat exchanger 3 (acting as an evaporator) to become a superheated gas refrigerant, which passes through the four-way switching valve 16 and the suction pipe 6 and the compressor 1
Return to. Next, at the time of heating, the four-way switching valve 16 is switched and the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 passes through the discharge pipe 5 and the four-way switching valve 16 as shown by the dotted line, and the indoor heat exchanger 3 (works as a condenser). Then, it is cooled, condensed, and reaches the electronic expansion valve 18. After being decompressed by the electronic expansion valve 18 to become a wet refrigerant, it is heated and evaporated by the outdoor heat exchanger 2 (acting as an evaporator) to become a superheated gas refrigerant, passing through the four-way switching valve 16 and passing through the suction pipe 6, and then the compressor. Return to 1. High voltage switch 1
7 is turned on when the discharge pressure is equal to or higher than a predetermined value, and is turned off when the discharge pressure is lower than another specified value. The capillary tube 7 artificially generates the evaporation temperature of the evaporator.

The discharge temperature thermistor 19 in FIG. 1 is for detecting the discharge temperature of the discharge gas discharged from the compressor 1, and the suction temperature thermistor 20 is the suction temperature of the refrigerant sucked into the compressor 1. The indoor heat exchanger temperature thermistor 21 is for detecting, and the evaporation temperature thermistor 22 is for detecting the condensation temperature during the heating operation.
Is for detecting the evaporation temperature artificially generated by the capillary tube 7.

Next, the operation of the first embodiment will be described.
FIG. 2 shows a control flow of this embodiment. When the separation type air conditioner is in operation, it is judged at step 101 whether the high pressure switch is ON or OFF, and when it is ON (step 102). Proceed to the electronic expansion valve 18 A
The pulse is opened, and the routine proceeds to step 103, where the compressor operating frequency is reduced by a Hz and the routine proceeds to step 104. Step 10
If the high-voltage switch is OFF in step 1, step 102 and step 103 are skipped and step 104 is proceeded to. When it is determined in step 104 that the indoor heat exchanger temperature detected by the indoor heat exchanger temperature thermistor 21 is equal to or higher than a predetermined value (x), the electronic expansion valve 18 is determined in step 105.
In step 106 for opening the B pulse, the compressor operating frequency is reduced by b Hz, and one control is ended. When it is determined in step 104 that the indoor heat exchanger temperature detected by the indoor heat exchanger temperature thermistor 21 is less than a specified value (x), steps 105 and 106 are not performed and one control is terminated. This control is repeatedly performed at intervals of T seconds.

As described above, in the air conditioner of the first embodiment, when the pressure on the high pressure side, the temperature of the indoor heat exchanger, and the discharge temperature rise and protection is required, the expansion valve is opened and the compressor operating frequency is lowered. This makes it possible to protect the compressor at low cost.

Example 2. Next, a second embodiment will be described. FIG. 3 shows a control flow of the second embodiment. When the separation type air conditioner is in operation and it is judged in step 201 that the discharge temperature detected by the discharge temperature thermistor 19 is equal to or higher than a predetermined value (y), In step 202, the electronic expansion valve 18 is opened by C pulse, and the process proceeds to step 203.
In step 203, the operating frequency of the compressor is lowered by cHz, and one control is ended. When it is determined in step 201 that the discharge temperature detected by the discharge temperature thermistor 19 is less than a specified value (y), steps 202 and 20.
3 is not performed and one control is ended. This control is repeatedly performed at intervals of T seconds.

As described above, according to the second embodiment, in the air conditioner, when the pressure on the high pressure side, the temperature of the indoor heat exchanger, and the discharge temperature rise and protection is required, the expansion valve is opened to operate the compressor. By lowering the frequency, the compressor can be protected at low cost.

Example 3. Next, a third embodiment will be described. FIG. 4 shows a control flow of the third embodiment. In step 301, it is determined whether the separation type air conditioner is in operation or stopped, and if it is stopped, in step 311 the electronic expansion valve is operated. 18 is fully opened to end the control. When it is determined in step 301 that the separation type air conditioner is in operation, the target compressor operating frequency and the target discharge temperature (Td trg) are determined in step 302.
Is determined and the process proceeds to step 303. After detecting the discharge temperature in step 303, it is determined in step 304 whether the discharge temperature (Td) detected in step 303 is higher or lower than the target discharge temperature Tdtrg. Td trg
When> Td, in step 307, the upper limit of the compressor operating frequency is limited to A Hz, and the process proceeds to step 308.
When Td trg <Td, the superheat is detected in step 306, and it is determined in step 306 whether it is the target superheat. If it is not the target superheat, in step 310 the electronic expansion valve is determined by the difference from the target superheat. The control is ended by correcting the opening. When it is determined in step 306 that it is the target superheat, the process proceeds to step 308. If it is the target discharge temperature in step 308, and if it is the target discharge temperature, the control is ended without correcting the opening degree of the electronic expansion valve, and if it is not the target temperature, the process proceeds to step 309 and the difference from the target temperature. The opening degree of the electronic expansion valve 18 is corrected according to the above, and the control ends.

As described above, according to the third embodiment, by limiting the upper limit operating frequency of the compressor until the discharge temperature rises, it is possible to suppress the carry-out of lubricating oil in the compressor and improve the reliability of the compressor. .

[0024]

The separated type air conditioner of claim 1 is a separated type air conditioner that performs cooling / heating operation using a refrigeration cycle in which a compressor, a four-way valve, an outdoor heat exchanger, a pressure reducing device, and an indoor heat exchanger are sequentially connected. In an air conditioner, a discharge pipe temperature sensor provided on the discharge side of the compressor, a suction pipe temperature sensor provided on the suction side of the compressor, between the outdoor heat exchanger and a decompression device, and the compression unit. An evaporative temperature sensor connected to the suction side of the compressor and provided in a circuit that artificially generates an evaporative temperature, and means for limiting the upper limit operating frequency of the compressor until the discharge pipe temperature exceeds a predetermined value. Preparation , separation
If it is determined that the type air conditioner is in operation, the target compressor operation
Determine the rotation frequency and target discharge temperature, and check the discharge pipe temperature.
The discharge temperature detected by the temperature sensor is higher than the target discharge temperature.
If it is too low, limit the upper limit of the compressor operating frequency,
The discharge temperature detected by the discharge pipe temperature sensor is
If the discharge temperature is higher than the mark, the suction pipe temperature sensor
And the superheat from the output of the evaporation temperature sensor
The decompression device is detected so that it becomes the target superheat.
Since the configuration is controlled, the upper limit of the compressor operating frequency is limited until the discharge temperature exceeds a predetermined value, and the compressor operating frequency is increased after the discharge temperature exceeds the predetermined value to freeze the compressor. It is possible to suppress the taking-out of machine oil and improve the reliability of the compressor.

[0025] according to claim 2 separate type air conditioner, according to claim 1
In the separation-type air conditioner described, a compressor, a four-way valve, an outdoor heat exchanger, a decompressor, and a separation-type air conditioner that performs cooling and heating operation using a refrigeration cycle in which an indoor heat exchanger is sequentially connected, When the high pressure switch provided on the discharge side of the machine is operated, the operating frequency of the compressor is lowered and the decompression device is opened, so that the discharge temperature exceeds a predetermined value. Operating frequency
Limit the upper limit of the number and compress after the discharge temperature exceeds the specified value
Refrigerator from compressor by increasing the operating frequency of the machine
You can suppress the oil carry-out and increase the reliability of the compressor.
In addition, when the high pressure switch detects an excessive high pressure and the compressor needs to be protected, the pressure reducing means can be opened to lower the operating frequency of the compressor to reduce the pressure on the high pressure side. it can.

The separate type air conditioner of claim 3 is the same as that of claim 1.
In the separation type air conditioner described, a compressor, a four-way valve, an outdoor heat exchanger, a decompression device, and a separation type air conditioner that performs cooling and heating operation using a refrigeration cycle in which an indoor heat exchanger is sequentially connected, When the value of the pipe temperature sensor provided in the heat exchanger exceeds a predetermined value, the operating frequency of the compressor is lowered and the decompression device is provided with a means for opening the discharge temperature. Pressure to exceed
The upper limit of the compressor operating frequency is limited, and the discharge temperature exceeds the specified value.
After that, increase the operating frequency of the compressor
Prevents refrigerating machine oil from being taken out of the machine and increases the reliability of the compressor.
It is possible to open the decompression means when the indoor pipe temperature sensor detects an excessive rise in high pressure and it is necessary to protect the compressor.
The operating frequency of the compressor can be reduced to reduce the pressure on the high pressure side, and the compressor can be protected at low cost.

A separate type air conditioner according to a fourth aspect is the first aspect.
In the separation-type air conditioner described, a compressor, a four-way valve, an outdoor heat exchanger, a decompressor, and a separation-type air conditioner that performs cooling and heating operation using a refrigeration cycle in which an indoor heat exchanger is sequentially connected, When the value of the discharge pipe temperature sensor provided on the discharge side of the machine exceeds a predetermined value, the operating frequency of the compressor is lowered and the decompression device is provided with a means for opening the discharge temperature. Exceeds a specified value
The upper limit of the compressor operating frequency is limited to the specified discharge temperature
By increasing the operating frequency of the compressor after exceeding the value
Compressor reliability is suppressed by preventing refrigeration oil from being taken out of the compressor.
When the discharge temperature rises and it is necessary to protect the compressor , it is possible to open the pressure reducing means and reduce the operating frequency of the compressor to reduce the pressure on the high-pressure side. it can.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram of a separation type air conditioner according to Examples 1 to 3 of the present invention.

FIG. 2 is a control flowchart according to the first embodiment.

FIG. 3 is a control flowchart according to the second embodiment.

FIG. 4 is a control flowchart according to the third embodiment.

FIG. 5 is a refrigeration cycle diagram of a conventional separation type air conditioner.

[Explanation of symbols]

1 compressor 2 Indoor heat exchanger 3 Outdoor heat exchanger 4 decompression device 5 discharge piping 6 suction pipe 7 Capillary tube 8 High pressure side solenoid valve 9 Accumulator 10 Low pressure solenoid valve 11, 12, 13, 14 Check valve 15 strainers 16 four-way switching valve 17 High voltage switch 18 Electronic expansion valve

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuo Yamashita 3-18-1, Oga, Shizuoka-shi Mitsubishi Electric Engineering Co., Ltd. Nagoya Office Shizuoka Branch (72) Inventor Kunihiro Inui 3--18, Oka, Shizuoka No. 1 Mitsubishi Electric Engineering Co., Ltd. Nagoya Office Shizuoka Branch (72) Inventor Hirokuni Suzuki 3-18-1 Oga, Shizuoka City Mitsubishi Electric Engineering Co., Ltd. Nagoya Office Shizuoka Branch (72) Inventor Okazaki Hajime 3-18-1, Oga, Shizuoka-shi Mitsubishi Electric Engineering Co., Ltd. Nagoya office Shizuoka branch (72) Inventor Mune Hiraoka 3--18-1, Oka, Shizuoka Mitsubishi Electric Engineering Co., Ltd. Nagoya business Shizuoka Branch (56) Reference JP-A-64-41770 (JP, A) JP-A-63-29035 5 (JP, A) JP-A-3-102141 (JP, A) JP-A-3-51667 (JP, A) JP-A-2-263054 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 1/00 371 F25B 1/00 101 F25B 1/00 304 F25B 1/00 341 F24F 11/02 102

Claims (4)

(57) [Claims] 1. A separation type air conditioner that performs cooling and heating operation using a refrigeration cycle in which a compressor, a four-way valve, an outdoor heat exchanger, a decompression device, and an indoor heat exchanger are sequentially connected, in the discharge side of the compressor. Discharge pipe temperature sensor provided in
A suction pipe temperature sensor provided on the suction side of the compressor, a connection between the outdoor heat exchanger and the decompression device, and the suction side of the compressor were provided and provided in a circuit that artificially generates an evaporation temperature. Equipped with evaporation temperature sensor , separate air conditioning
If it is determined that the compressor is in operation, the target compressor operating frequency and
And the target discharge temperature, and the discharge pipe temperature sensor
If the discharge temperature detected in is lower than the target discharge temperature,
If the upper limit of the compressor operating frequency is limited,
The discharge temperature detected by the pipe temperature sensor is the target discharge
If the temperature is higher than the temperature, the suction pipe temperature sensor and the steam
Superheat is detected by the output of the temperature sensor,
Control the decompressor to achieve the target superheat
A separate type air conditioner characterized by: 2. A separation type air conditioner that performs cooling and heating operation using a refrigeration cycle in which a compressor, a four-way valve, an outdoor heat exchanger, a decompression device, and an indoor heat exchanger are sequentially connected, the discharge side of the compressor. when the high pressure switch provided is activated to, the lower the operation frequency of the compressor, to claim 1, further comprising a means for opening the pressure reducing device
Separated air conditioner described . 3. A separation type air conditioner that performs cooling and heating operation using a refrigeration cycle in which a compressor, a four-way valve, an outdoor heat exchanger, a decompression device, and an indoor heat exchanger are sequentially connected to each other. The separation type air according to claim 1 , further comprising: a means for lowering the operating frequency of the compressor and opening the decompression device when the value of the provided pipe temperature sensor exceeds a predetermined value. Harmony machine. 4. A separation-type air conditioner that performs cooling and heating operation using a refrigeration cycle in which a compressor, a four-way valve, an outdoor heat exchanger, a pressure reducing device, and an indoor heat exchanger are sequentially connected, the discharge side of the compressor. 2. The separation unit according to claim 1 , further comprising means for lowering the operating frequency of the compressor and opening the decompression device when the value of the discharge pipe temperature sensor provided in the unit exceeds a predetermined value. Type air conditioner.