KR100645905B1 - Defrosting method of heat pump air conditioner - Google Patents

Abstract

A defrosting method of a heat-pump type air conditioner is provided to improve stability and accuracy compared to cases of using only a frost temperature sensor or using only pipe temperature and outdoor temperature by regarding the frost temperature, outdoor temperature, and pipe temperature altogether. A defrosting method of a heat-pump type air conditioner consists of steps for comparing pipe temperature(Todc) sensed by a pipe temperature sensor with a first set value; judging which temperature(Tf) sensed by a frost temperature sensor installed separately from an outdoor heat exchanger approaches to the pipe temperature or outdoor temperature(Tod.air) sensed by an outdoor temperature sensor(S3); comparing a difference between the pipe temperature and the frost temperature with a second set value; and starting a defrosting work if the pipe temperature is under the first set value, if the frost temperature is closer to the pipe temperature the difference between the pipe temperature, and if the frost temperature is under the second set value(S4).

Description

Defrosting method of heat pump air conditioner

1 is a schematic block diagram showing a refrigerant flow when the heat pump type air conditioner according to the prior art is a cooling / heating operation.

2 is a schematic configuration diagram of a heat pump type air conditioner to which a defrosting operation method of a heat pump type air conditioner according to the present invention is applied;

3 is a flow chart of an embodiment of a defrosting operation method of a heat pump type air conditioner according to the present invention.

<Explanation of symbols on main parts of the drawings>

32: pipe temperature sensor 34: outdoor temperature sensor

36: implantation temperature sensor 38: control unit

Todc: Piping Temperature Tod.air: Outdoor Temperature

Tf: Temperature detected by the immersion pipe sensor T1: First setpoint

T2: second set value t: set time

The present invention relates to a defrosting operation method of a heat pump type air conditioner. In particular, it is determined whether to perform a defrosting operation in consideration of the outdoor temperature and the piping temperature as well as the temperature sensed by the frosting temperature sensor installed apart from the outdoor heat exchanger. It relates to a defrosting operation method of a heat pump type air conditioner.

1 is a schematic block diagram showing a refrigerant flow when the heat pump type air conditioner according to the prior art is a cooling / heating operation.

As shown in FIG. 1, a conventional air conditioner includes an indoor heat exchanger (2) that cools or heats ambient air while the refrigerant evaporates or condenses, and blows indoor air (I) to the indoor heat exchanger (2). The indoor fan 3 and the indoor heat exchanger 2 act as a condenser where the refrigerant acts as a condenser, and when the indoor heat exchanger 2 acts as a heater, the outdoor acts as an evaporator where the refrigerant evaporates. The heat exchanger 4, the outdoor fan 5 for blowing outdoor air O to the outdoor heat exchanger 4, and the high temperature and high pressure gas to the indoor heat exchanger 2 or the outdoor heat exchanger 4. A compressor (6) for compressing a low-temperature, low-pressure gaseous refrigerant to supply a refrigerant, and an accumulator (7) such that a liquid refrigerant is stored in the refrigerant sucked into the compressor (6) and only gas refrigerant is sucked into the compressor (6). )Wow; An expansion mechanism (8) installed between the indoor heat exchanger (2) and the outdoor heat exchanger (4) to expand the refrigerant at low temperature and low pressure, and a flow path of the refrigerant according to a cooling / heating operation mode of the air conditioner. It comprises a four-way valve 10 installed in the outlet pipe of the compressor (6) to switch.

The compressor (6), the four-way valve (10), the indoor heat exchanger (2), the expansion mechanism (8), the outdoor heat exchanger (4), the four-way valve (10), the ambulator (7), and the compressor (6) It is connected to the refrigerant pipe.

The four-way valve 10 guides the high temperature and high pressure gas refrigerant (dotted line) compressed by the compressor 6 to the outdoor heat exchanger 4 during the cooling operation and the defrosting operation of the multi-type air conditioner. The refrigerant evaporated in the apparatus 2 is guided to the accumulator 7, and the high temperature and high pressure gas refrigerant (solid line) compressed by the compressor 6 during the heating operation of the multi-type air conditioner is connected to the indoor heat exchanger ( 2) and the refrigerant evaporated in the outdoor heat exchanger (4) to the accumulator (7).

The indoor heat exchanger 2 and the indoor fan 3 are installed in the indoor unit 20.

The outdoor heat exchanger 4, the outdoor fan 5, the compressor 6, the accumulator 7, and the four-way valve 10 are installed in the outdoor unit 30.

The expansion mechanism 8 is installed on at least one side of the indoor unit 20 and the outdoor unit 30.

The outdoor unit 30 is provided with a pipe temperature sensor 32 in the outdoor heat exchanger 4 to measure the pipe temperature of the outdoor unit 30.

The conventional multi-type air conditioner configured as described above turns on the compressor 6 and switches the four-way valve 10 to the heating mode during the heating operation.

When the compressor 6 is turned on, the high temperature and high pressure gas refrigerant compressed by the compressor 6 is guided to the indoor heat exchanger 2 by the four-way valve 10, and the indoor heat exchanger 2 is turned on. Condensed while releasing heat to the surroundings while passing through, and decompressed while passing through the expansion mechanism (8), the surrounding heat is taken away while passing through the outdoor heat exchanger (4), and evaporated with the four-way valve (10). After passing through the radar 7, it is circulated to the compressor 6.

When the frost on the surface of the outdoor heat exchanger 4 is formed during the heating operation as described above, the multi-type air conditioner starts the defrosting operation so that the multi-type air conditioner has the same refrigerant flow as the cooling operation.

Hereinafter, the defrosting operation of the conventional heat pump type air conditioner will be described in more detail.

The multi-type air conditioner switches the four-way valve 10 to the cooling mode when the pipe temperature detected by the pipe temperature sensor 32 is lower than the defrost start temperature.

In the cooling mode of the four-way valve 10, the high-temperature and high-pressure refrigerant compressed by the compressor 6 is introduced into the outdoor heat exchanger 4 to remove frost formed on the outdoor heat exchanger 4. The pressure is reduced while passing through the expansion mechanism (8), the surrounding heat is evaporated by passing through the indoor heat exchanger (2), and after passing through the four-way valve (10) and the accumulator (7), the compressor ( 6), the refrigerant removes the frost formed on the outdoor heat exchanger (4) while repeating the above cycle.

When the frost that has been implanted on the outdoor heat exchanger 4 is sufficiently removed, the temperature of the outdoor heat exchanger 4 is increased, and when the pipe temperature detected by the pipe temperature sensor 32 exceeds the defrost end temperature, the multi-type The air conditioner switches the four-way valve 10 back to the heating mode to end the defrosting operation and resume the heating operation.

Meanwhile, the heat pump type air conditioner sets a difference between the pipe temperature of the outdoor heat exchanger 4 detected by the pipe temperature sensor 32 and the outdoor temperature detected by the outdoor temperature sensor (not shown) in addition to the defrosting operation method as described above. It is also possible to start defrosting operation when the temperature difference is reached.

However, in the defrosting operation method of the heat pump type air conditioner according to the prior art, the method of starting the defrosting operation by comparing the pipe temperature detected by the pipe temperature sensor 32 with the defrosting start temperature, and in the pipe temperature sensor 32 If the difference between the detected temperature of the outdoor heat exchanger 4 and the outdoor temperature detected by the outdoor temperature sensor (not shown) is greater than or equal to the set temperature difference, the method of initiating the defrosting operation may not detect the frosting directly. The time is longer than necessary, there is a problem that the heating operation rate is lowered.

On the other hand, one temperature sensor (not shown) is installed in close proximity to the outdoor heat exchanger (4) so that the one temperature sensor directly detects the implantation of the outdoor heat exchanger (4) to determine whether defrosting operation There is also a defrosting operation method of a heat pump type air conditioner using a temperature sensor.

In the defrosting operation method using the one temperature sensor, the temperature is periodically detected and the difference between the stored reference temperature and the measured value is compared with the designated comparison data to start and end the defrosting operation, but start / end the defrosting operation. In order to use only the temperature sensed by one temperature sensor, there is a problem that the accuracy is low.

The present invention has been made to solve the above problems of the prior art, in consideration of the outdoor temperature and the pipe temperature as well as the temperature detected by the implantation temperature sensor, when using only the implantation temperature sensor or using only the piping temperature and the outdoor temperature It is an object of the present invention to provide a defrosting operation method of a heat pump type air conditioner with higher stability and accuracy.

Defrosting operation method of the heat pump type air conditioner according to the present invention for solving the above problems is the pipe temperature (Todc) and the first set value (T1) detected by the pipe temperature sensor during the heating operation of the heat pump type air conditioner Comparing the first step; A second temperature determining whether the temperature Tf detected by the frost temperature sensor spaced apart from the outdoor heat exchanger is closer to the temperature of the pipe temperature Todc and the outdoor temperature Tod.air detected by the outdoor temperature sensor; Steps; A third step of comparing a difference between the pipe temperature Todc and the temperature Tf detected by the implantation temperature sensor with a second set value T2; In the first step, the pipe temperature Todc is less than the first set point T1, and in the second step, the temperature Tf detected by the implantation temperature sensor is closer to the pipe temperature Todc. And, in the third step, if the difference between the pipe temperature Todc and the temperature Tf detected by the implantation temperature sensor is equal to or less than a second set value T2, a fourth step of starting defrosting operation. It features.

In addition, the first set value (T1) is characterized in that -6 ℃.

The second step may include a difference between the outdoor temperature Tod.air and the temperature Tf detected by the temperature sensor, and the pipe temperature Todc and the temperature Tf detected by the temperature sensor. It is characterized by comparing the magnitude of the difference.

In addition, the second set value (T2) is characterized in that 1 ° C.

The defrosting operation method of the heat pump type air conditioner is characterized in that the defrosting operation is terminated when the pipe temperature Todc exceeds the third set value T3.

In addition, the third set value (T3) is characterized in that 12 ° C.

The defrosting operation method of the heat pump type air conditioner may be configured to determine whether to start the defrosting operation after the compressor is driven for a set time t or more after the heating operation starts.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic configuration diagram of a heat pump type air conditioner to which a defrosting operation method of a heat pump type air conditioner according to the present invention is applied.

The same configuration as the conventional one uses the same reference numerals and detailed description thereof will be omitted.

The heat pump type air conditioner illustrated in FIG. 2 includes a pipe temperature sensor 32 installed in the outdoor heat exchanger 4 and measuring a pipe temperature Todc of the outdoor heat exchanger 4.

The heat pump type air conditioner further includes an outdoor temperature sensor 34 installed in the outdoor unit 30 to sense outdoor temperature (Tod, air).

 The heat pump type air conditioner is surrounded by frost when the outdoor heat exchanger 4 is implanted to sense the temperature of the outdoor heat exchanger 4, and is spaced apart from the outdoor heat exchanger 4 when the outdoor heat exchanger 4 is defrosted. It further comprises an implantation temperature sensor 36 installed in the outdoor unit 30 spaced apart from the outdoor heat exchanger 4 and a predetermined interval (a) to sense the temperature.

The heat pump type air conditioner includes an outdoor temperature (Tod.air) detected by the outdoor temperature sensor (4), a pipe temperature detected by the pipe temperature sensor (32), and a sensed temperature by the implantation temperature sensor (36). It further comprises a control unit 38 for determining the start of defrost of the outdoor heat exchanger (4) by using all the temperature (Tf).

Figure 2 is a flow chart of one embodiment of a defrosting operation method of a heat pump type air conditioner according to the present invention.

The controller 38 determines whether the defrost is started when the compressor 5 is driven for a predetermined time (t: 30 minutes, for example) during heating operation. (S1) (S2) (S3)

The controller 38 compares the pipe temperature Todc detected by the pipe temperature sensor 32 with the first set value T1 when the set time t has elapsed.

Here, it is preferable that the first set value T1 is set to approximately −6 ° C., which is lower than −5 ° C., which is a temperature at which an implantation usually occurs.

In addition, the controller 38 may determine that the temperature Tf detected by the temperature sensor 36 is selected from the pipe temperature Todc and the outdoor temperature Tod.air detected by the outdoor temperature sensor 34. Determine if closer to temperature.

Here, the proximity determination of the temperature Tf detected by the implantation temperature sensor 36 may include a difference between the outdoor temperature Tod.air and the temperature Tf detected by the implantation temperature sensor 36 and the pipe. It is most preferable to compare the magnitude of the difference between the temperature Todc and the temperature Tf sensed by the implantation temperature sensor 36, and the temperature detected by the outdoor temperature Tod.air and the implantation temperature sensor 36. If the difference in temperature Tf is greater than the difference between the pipe temperature Todc and the temperature Tf detected by the implantation temperature sensor 36, the temperature Tf detected by the implantation temperature sensor 36 is the pipe temperature. Since the conception is close to Todc, the conception is in progress, and vice versa, the temperature Tf detected by the conception temperature sensor 36 is close to the outdoor temperature Todc, and thus the conception is not performed.

In addition, the controller 38 compares the difference between the pipe temperature Todc and the temperature Tf detected by the implantation temperature sensor 36 with a second set value T2.

Here, the second set value (T2) is a difference between the pipe temperature (Todc) and the temperature (Tf) detected by the temperature sensor (36) sufficient to determine the outdoor heat exchanger (4) as an implantation, too. The higher the setting, the lower the accuracy of implantation detection.

Then, the controller 38, the pipe temperature Todc is less than the first set value (T1) (hereinafter referred to as 'condition 1'), the temperature Tf detected by the implantation temperature sensor 36 is It is closer to the pipe temperature Todc (hereinafter referred to as 'condition 2'), and the difference between the pipe temperature Todc and the temperature Tf detected by the implantation temperature sensor 36 is the second set value T2. ) If all three conditions below (hereinafter referred to as 'Condition 3') are satisfied, the outdoor heat exchanger 4 is judged to have been defrosted, and defrosting operation is started, and any one of the above three conditions is not satisfied. If not, the heating operation is continued until the above three conditions are satisfied without starting the defrosting operation in order to prevent unnecessary defrosting operation.

The control unit 38 starts defrosting operation when the heat pump type air conditioner satisfies all three conditions.

That is, the controller 38 turns off the compressor 6 (on after a three minute delay), turns off the indoor fan 3 and the outdoor fan 5, and when 30 seconds have elapsed after the compressor 6 is turned off. The four-way valve 10 is switched to the cooling mode (defrost mode). (S4)

The controller 38 forcibly drives the compressor 6 for 5 minutes and stops driving after 6 minutes (S5).

In addition, the controller 38 determines whether the defrosting is finished by comparing the pipe temperature Todc with the third set value T3.

Here, it is most preferable to set the third set value T3 to 12 ° C., which is a temperature at which defrost is terminated.

The controller 38 determines that the defrost is not terminated when the pipe temperature Todc is less than or equal to the third set value T3, forcibly driving the compressor 38 again for 5 minutes and stopping the drive again after 6 minutes. The forced drive / drive stop of the compressor 38 and the comparison between the pipe temperature Todc and the third set value T3 are repeated until the pipe temperature Todc exceeds the third set value T3.

The controller 38 determines that the defrosting operation is finished when the pipe temperature Todc exceeds the third set value T3 and resumes the heating operation.

That is, the controller 38 turns on the outdoor fan 5, turns off the compressor 6 (on after a three minute delay), and turns off the four-way valve 10 when 30 seconds have elapsed after turning off the compressor 6. Switch to heating mode (S7).

Thereafter, the controller 38 operates the indoor fan 3 in the 'strong' mode. (S8)

In addition, this invention is not limited to said embodiment, It is applicable also when the start of a defrosting operation, the completion of a defrosting operation, the specific procedure of resuming heating operation, etc. differs from the above-mentioned embodiment, and this invention is Of course, the various implementations are possible within the technical scope to which they belong.

In the defrosting operation method of the heat pump type air conditioner of the present invention configured as described above, the pipe temperature Todc is less than the first set value T1, and the temperature Tf detected by the implantation temperature sensor is the outdoor temperature Tod. .air) is closer to the pipe temperature Todc, and if the difference between the pipe temperature Todc and the temperature Tf detected by the temperature sensor is less than or equal to the second set value T2, the defrosting operation is started to produce a pipe temperature. Defrosting can be detected directly when using only the pipe, or by using only the pipe temperature and the outdoor temperature together, and it is possible to accurately detect the temperature or the degree of defrosting around the temperature sensor than when using only the temperature sensor. It has the advantage of high stability and accuracy.

In addition, in the defrosting operation method of the heat pump type air conditioner of the present invention, the pipe temperature Todc is greater than or equal to the first set value T1, or the temperature Tf detected by the frost temperature sensor is outside the pipe temperature Todc. If the temperature is closer to Tod.air or if the difference between the pipe temperature Todc and the detected temperature Tf is greater than the second set value T2, the defrosting operation is not started, thus preventing unnecessary defrosting operations. It is possible to increase the heating operation rate.

In the defrosting operation method of the heat pump type air conditioner of the present invention, when the first set value T1 is set to -6 ° C, which is lower than -5 ° C, which is a temperature at which an implantation usually occurs, when the conception is assured, Since the defrosting operation is started, there is an advantage of high accuracy.

In addition, the defrosting operation method of the heat pump type air conditioner of the present invention, the second set value (T2) is set to 1 ℃, it can prevent the erroneous false detection that may occur when the second set value is set too high. There is an advantage to that.

Claims (7)

In the heating operation of the heat pump type air conditioner, A first step of comparing the pipe temperature Todc detected by the pipe temperature sensor with the first set value T1;  A second temperature determining whether the temperature Tf detected by the frost temperature sensor spaced apart from the outdoor heat exchanger is closer to the temperature of the pipe temperature Todc and the outdoor temperature Tod.air detected by the outdoor temperature sensor; Steps; A third step of comparing a difference between the pipe temperature Todc and the temperature Tf detected by the implantation temperature sensor with a second set value T2; In the first step, the pipe temperature Todc is less than the first set value T1, In the second step, the temperature (Tf) detected by the implantation temperature sensor is closer to the pipe temperature (Todc), In the third step, if the difference between the pipe temperature (Todc) and the temperature detected by the temperature sensor (Tf) is less than the second set value (T2), comprising a fourth step of starting a defrosting operation A defrosting operation method of a heat pump type air conditioner. The method of claim 1, The first set value (T1) is a defrosting operation method of the heat pump type air conditioner, characterized in that -6 ℃. The method of claim 1, The second step may include a difference between the outdoor temperature Tod.air and a temperature Tf detected by the implantation temperature sensor and a difference between the pipe temperature Todc and the temperature Tf detected by the implantation temperature sensor. Defrosting operation method of the heat pump type air conditioner, characterized in that the comparison of the magnitude. The method of claim 1, The second set value (T2) is a defrosting operation method of a heat pump type air conditioner, characterized in that 1 ° C. The method of claim 1, The defrosting operation method of the heat pump type air conditioner is a defrosting operation method of the heat pump type air conditioner, characterized in that the defrosting operation is terminated when the pipe temperature Todc exceeds the third set value T3. The method of claim 5, The third set value (T3) is a defrosting operation method of the heat pump type air conditioner, characterized in that 12 ℃. The method according to claim 1 to 6, The defrosting operation method of the heat pump type air conditioner includes determining whether to start the defrosting operation after the compressor has been driven for a set time (t) or more after the start of the heating operation. Driving way.

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