CN111698874B

CN111698874B - Air conditioner heat dissipation method and device and air conditioner

Info

Publication number: CN111698874B
Application number: CN202010382191.8A
Authority: CN
Inventors: 秦臻; 张伟; 郝宇婷
Original assignee: Qingdao University of Technology
Current assignee: Qingdao University of Technology
Priority date: 2020-05-08
Filing date: 2020-05-08
Publication date: 2022-06-24
Anticipated expiration: 2040-05-08
Also published as: CN111698874A

Abstract

The invention discloses an air conditioner heat dissipation method, a heat dissipation device and an air conditioner, wherein the method comprises the following steps: acquiring the sampling temperature of the radiator; comparing the sampling temperature with a set temperature threshold; when the sampling temperature is not greater than the set temperature threshold value, controlling the wind direction of the radiator in the wind field to be kept in a first wind direction for operation; when the sampling temperature is larger than the set temperature threshold value, controlling the wind direction of the wind field in which the radiator is located to change to a second wind direction for operation; the second wind direction is opposite to the first wind direction. The invention can reduce the thermal stress of the air conditioner radiator caused by uneven temperature and improve the use safety performance of the heating device.

Description

Air conditioner heat dissipation method and device and air conditioner

Technical Field

The invention belongs to the technical field of air conditioning, particularly relates to an air conditioner, and more particularly relates to a heat dissipation method and a heat dissipation device of the air conditioner and the air conditioner.

Background

The inverter of the air conditioner is usually provided with heating devices such as a silicon bridge and an IPM module, and the heating devices generate more and more heat along with the increase of the current of the air conditioner in the use process of the air conditioner. The device life-span reduction can be caused in the generating heat of device that generates heat, in order to guarantee the life of device, can give the converter heat dissipation through the radiator usually to reduce the temperature of the device that generates heat on the converter.

The air conditioner is provided with the fan, the fan rotates to form an air field, and the heat dissipation of the radiator can be accelerated by utilizing the air field. Taking top air outlet as an example, referring to fig. 1 and 2, when the air conditioner is in operation, the fan 11 rotates in one direction to form an air field with an air supply direction from bottom to top, and in fig. 2, the air supply direction is from the a end to the B end. The rotation direction of the fan 11 is fixed, and the air supply direction of the wind field is also fixed. Generally, the temperatures of different positions of the heat sink 12 will have a certain temperature difference under the influence of the air blowing direction, and particularly, when the long side of the heat generating device 13 is along the air blowing direction, the temperature difference between the two ends of the heat generating device 13 is large, so as to form a thermal stress on the heat generating device 13. Taking the heat generating device 13 as an IPM as an example, as shown in fig. 3, 6 IGBTs are arranged inside the IPM, and the arrangement position is shown in fig. 3. The 6 IGBTs are turned on and off according to a control rule, and in principle, the heat generation amounts of the 6 IGBTs are the same. However, in a wind field in which the air blowing direction is fixed, heat is concentrated toward the far end (B end) of the air blowing by the heat radiation action of the radiator 12 along the air blowing direction. Therefore, in actual use, the temperature of the IGBT1 at the upper end (near the far wind end B) of the IPM is higher than the temperature of the IGBT3 at the lower end (near the near wind end a), causing an imbalance in IPM temperature, resulting in large thermal stress on the upper and lower sides of the IPM. Due to the accumulation of the thermal stress, the service life of the heat generating device 13 is reduced by a light person, and the device is broken and damaged in a serious case, so that potential safety hazards are caused.

Disclosure of Invention

The invention aims to provide an air conditioner heat dissipation method, a heat dissipation device and an air conditioner, which are used for reducing thermal stress generated by a heat radiator due to uneven temperature and improving the use safety performance of a heating device.

In order to realize the purpose of the invention, the invention is realized by adopting the following technical scheme:

the invention provides a heat dissipation method of an air conditioner, which comprises the following steps:

acquiring the sampling temperature of the radiator;

comparing the sampling temperature with a set temperature threshold;

when the sampling temperature is not greater than the set temperature threshold value, controlling the wind direction of the radiator in the wind field to be kept in a first wind direction for operation; when the sampling temperature is larger than the set temperature threshold value, controlling the wind direction of the wind field in which the radiator is located to change to a second wind direction for operation; the second wind direction is opposite to the first wind direction.

The invention also provides a heat dissipating double-fuselage of the air conditioner, including the heat sink for the heat-generating device dispels the heat, also include:

the sampling temperature acquisition unit is used for acquiring the sampling temperature of the radiator;

the sampling temperature comparing unit is used for comparing the sampling temperature acquired by the sampling temperature acquiring unit with a set temperature threshold;

the control unit is at least used for controlling the wind direction of the wind field in which the radiator is positioned to be kept in a first wind direction to operate when the sampling temperature is not larger than the set temperature threshold value; the sampling temperature is higher than the set temperature threshold value, and the wind direction of the wind field in which the radiator is located is controlled to change to a second wind direction for operation; the second wind direction is opposite to the first wind direction.

The invention also provides an air conditioner which comprises a heating device and the air conditioner heat dissipation device.

Compared with the prior art, the invention has the advantages and positive effects that: according to the air conditioner heat dissipation method and the heat dissipation device, the sampling temperature of the radiator is obtained, when the sampling temperature is not greater than the set temperature threshold value, the temperature difference of different positions of the radiator is judged to be small, and the wind direction of the radiator in the wind field is controlled to be kept in the first wind direction to operate; when the sampling temperature is greater than a set temperature threshold value, judging that the temperature difference at different positions of the radiator is large, and under the condition, controlling the wind direction of the radiator in the wind field to be changed into a second wind direction to operate, wherein the second wind direction is opposite to the first wind direction; from this, when the difference in temperature of radiator is great, the wind direction of control wind field is reverse, and the heat dissipation direction is reverse change too to reduce the difference in temperature at radiator both ends gradually, and then reduce the thermal stress that easily produces because of the radiator temperature is uneven, carry out effectual protection to the device that generates heat, solve because of thermal stress accumulation reduces the life problem and other potential safety hazard problems of the device that generates heat, improved the safety in utilization performance of the device that generates heat.

Other features and advantages of the present invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic diagram of a heat sink of an air conditioner in the prior art;

FIG. 2 is a schematic diagram of the heat dissipation principle of FIG. 1;

FIG. 3 is a schematic view of the internal structure of the heat generating device of FIG. 2;

fig. 4 is a partial structural schematic view of an embodiment of an air conditioner according to the present invention;

FIG. 5 is an exploded view of a portion of FIG. 4;

FIG. 6 is a schematic view of the air conditioner of FIG. 4 in a first operating condition;

FIG. 7 is a schematic view of the air conditioner of FIG. 4 in a second operating state;

fig. 8 is a flowchart of an embodiment of a heat dissipation method of an air conditioner according to the present invention;

FIG. 9 is a schematic diagram of one embodiment of the acquisition of the sampled temperature of the heat sink of FIG. 8;

fig. 10 is a schematic structural view of an embodiment of a heat dissipation device of an air conditioner according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and embodiments.

It should be noted that in the description of the present invention, the terms of direction or positional relationship indicated by the terms "upper", "lower", "front", "rear", etc. are based on the directions or positional relationships shown in the drawings, which are only for convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Fig. 4 to 7 show an embodiment of an air conditioner according to the present invention, wherein fig. 1 is a schematic view of a partial structure of the embodiment, fig. 5 is an exploded schematic view of a partial structure of fig. 4, and fig. 6 and 7 are schematic views of the air conditioner in a first operating state and a second operating state, respectively.

As shown in fig. 4 to 7, the air conditioner of the embodiment is a top-outlet air conditioner, and includes a fan 21, an electrical box 22 and a heat sink 23, where the fan 21 is located on the upper portion of the electrical box 22 and is used to form a heat dissipation wind field, and is matched with the heat sink 23 to dissipate heat of the electrical box 22. The electric box 22 is provided with a heating device 221, and the heating device 221 is fixed with the radiator 23 to improve the heat dissipation effect. Furthermore, the rotation direction of the fan 21 is variable in order to achieve a reduction in thermal stress generated during heat dissipation. Specifically, when the fan 21 rotates in a first rotation direction (usually, a forward rotation direction), an air field with a first wind direction from bottom to top is formed, and at this time, the air conditioner is in a first working state shown in fig. 6 and in a normal heat dissipation working state; when the fan 21 rotates in a second rotation direction (the second rotation direction is opposite to the first rotation direction, and when the first rotation direction is a forward rotation direction, the second rotation direction is a reverse rotation direction), a wind field with a second wind direction from top to bottom is formed, and at this time, the air conditioner is in a second working state shown in fig. 7, which is a heat dissipation working state for reducing thermal stress.

For the air conditioner having the above-described structure, heat dissipation is performed using the air conditioner heat dissipation method flow shown in fig. 8.

Specifically, as shown in fig. 4 to 7, the heat dissipation method of the air conditioner according to the embodiment performs heat dissipation by using a heat dissipation process configured by the following process steps.

Step 81: the sampled temperature of the heat sink is obtained and compared to a set temperature threshold.

The sampling temperature of the radiator is the temperature on the radiator, and the size of the sampling temperature can reflect whether thermal stress is easy to generate.

In some preferred embodiments, the following method is used to acquire and determine the sampled temperature of the heat sink:

as shown in fig. 9, a schematic diagram of a structure of an embodiment of obtaining a sampled temperature of a radiator, temperature detection units a and B are respectively disposed on both ends of the radiator 23 in an air blowing direction. As shown in conjunction with fig. 6, in this embodiment, the temperature detection unit a and the temperature detection unit B are located at the lower end and the upper end of the radiator 23, respectively. More specifically, the lower end where the temperature detection unit a is located is the near-wind end in the first wind direction (from bottom to top), and the upper end where the temperature detection unit B is located is the far-wind end in the first wind direction. The real-time temperature TA of the lower near-wind end of the first wind can be obtained by using the temperature detection unit A; by using the temperature detection unit B, the real-time temperature TB of the far wind end under the first wind can be obtained. Then, the sampled temperature Tfin of the radiator is determined using the following equation: tfin = a TA + b TB.

In the above formula for determining Tfin, a and b are set coefficients, and satisfy: a + b = 1. a. The value of b is related to the position of the heating device 221 for dissipating heat through the heat sink 23, and the specific value is determined according to the comprehensive evaluation of experimental measurement.

Through the sampling temperature who gathers two different positions of radiator, determine the sampling temperature Tfin of radiator after setting for coefficient processing, the position of gathering the temperature and the size of setting for the coefficient are rationally selected according to the position of the device that generates heat, make sampling temperature reasonable, reflect the difference in temperature of the device that generates heat suitably, so that rationally, decide whether need carry out the processing that reduces thermal stress in time, can enough carry out timely effectual protection to the device that generates heat, and can not cause frequent protection yet, avoid reducing the refrigeration/heating effect of air conditioner self because of frequently carrying out the protection of the device that generates heat.

The air conditioner also prestores a set temperature threshold value, and after the sampling temperature of the radiator is obtained, the set temperature threshold value is compared with the sampling temperature of the radiator. The set temperature threshold is a threshold temperature value for determining whether a thermal stress reduction protection measure is to be implemented, and the value of the threshold temperature value can be determined by experiment and experience.

Step 82: and judging whether the sampling temperature of the radiator acquired in real time is greater than a set temperature threshold value. If yes, go to step 84; otherwise, step 83 is performed.

Step 83: if the sampling temperature of the radiator obtained in real time is judged to be not more than the set temperature threshold value, the temperature difference of different positions of the radiator 23 is considered to be small, correspondingly, the temperature difference on the heating device is also small, and the problems of damage and the like of the heating device caused by the overlarge temperature difference are not easy to occur, the wind direction of the radiator in the wind field is controlled to be kept in the first wind direction to operate, specifically, the fan 21 is controlled to work in the first rotating direction, the air conditioner is in the first working state of the figure 6, and the normal heat dissipation operation of the heating device is carried out.

Step 84: if the sampling temperature of the radiator obtained in real time is judged to be larger than the set temperature threshold value, the temperature difference of different positions of the radiator 23 is considered to be larger at the moment, correspondingly, the temperature difference on the heating device is also larger, and the wind direction in the wind field where the radiator is located is controlled to be changed into the second wind direction to operate. Specifically, the fan 21 is controlled to rotate in the reverse direction, and the second rotation direction is operated downward. At this time, the air conditioner is in the second operation state shown in fig. 7.

When the sampling temperature of the radiator is greater than the set temperature threshold value, the wind direction of the wind field is controlled to be reversed, the heat dissipation direction is also changed in a reversed way, the temperature at the upper end of the radiator 23 is higher than that at the lower end when the first wind is downward, the temperature at the lower end of the radiator 23 is gradually increased when the second wind after the wind direction is changed is downward, and correspondingly, the temperature at the upper end of the radiator is gradually decreased, so that the temperature difference at the two ends of the radiator 23 is gradually decreased, the temperature difference at the two ends of the heating device 221 is correspondingly decreased, the thermal stress generated due to large temperature difference is further reduced, the heating device 221 is effectively protected, the problem that the service life of the heating device is shortened due to the accumulation of the thermal stress and other potential safety problems are solved, and the use safety performance of the heating device is improved.

Although the temperature difference between both ends of the radiator 23 can be reduced after changing the wind field by controlling the fan 21 to rotate in the reverse direction, the amount of the air-conditioning heat radiation in a short time is insufficient because the fan 21 operates in the first rotation direction during normal heat radiation. Since the heat transfer efficiency of the air conditioner refrigerant is deteriorated due to insufficient amount of heat radiation air, it is necessary to consider the overall operation performance of the air conditioner while maintaining the heat-retaining device. Therefore, in some preferred embodiments, the air conditioner heat dissipation method further includes the following processes:

and starting timing from the control of changing the wind direction of the radiator in the wind field into a second wind direction, and changing the wind direction of the radiator in the wind field into the first wind direction when the timing time reaches the set operation time. That is, the operation time after changing the wind direction in the wind field is restricted, the problem that the heat conversion efficiency of the air conditioner is deteriorated due to long-time operation is avoided, and the protection of a heating device and the balance of heat exchange efficiency are achieved.

For the set operation time, a fixed time may be preset. However, in consideration of the dynamic change of the air conditioner system, the set operation time is preferably variable in real time in order to improve the air conditioner operation performance. Specifically, the set operation time is determined in real time according to the sampling temperature of the radiator acquired in real time and the exhaust pressure of the air conditioner acquired in real time. The obtaining of the exhaust pressure of the air conditioner is performed in the process of controlling the wind direction in the wind field where the radiator is located to be changed into the second wind direction for operation, and may be specifically obtained by collecting the exhaust pressure through a pressure sensor arranged in an exhaust pipeline.

In other preferred embodiments, a PID algorithm is used to determine the set operating time in real time based on the sampled temperature and exhaust pressure. The specific determination method comprises the following steps:

the set running time t is determined in real time according to the following formula:

t＝Kp×{⊿Tfin(n)－⊿Tfin(n-1)}＋Ki×⊿Tfin(n)×DT

＋Kd×{⊿Tfin(n)－2×⊿Tfin(n-1)＋⊿Tfin(n-2)}/DT

-Ks×{⊿Pd(n)－⊿Pd(n-1) }

in which (delta Tfin (n) = Tfin (n) -Tdo, (n-1) = Tfin (n-1) -Tdo),

⊿Tfin(n-2)=Tfin(n-2)－Tdo，⊿Pd(n)=Pd(n)－Pdo,

⊿Pd(n-1)=Pd(n-1)－Pdo,

wherein n is sampling time, Tfin is sampling temperature, Tdo is known protection temperature of the heating device, Pd is the exhaust pressure, Pdo is known protection pressure, Kp, Ki, Kd, Ks are known PID control coefficients, and DT is control period.

In one embodiment, the PID control parameter values and control periods are as follows:

Kp=4，Ki=1/60，Kd=120，Ks=40，DT=60S。

in the above embodiments, the top-outlet air conditioner is taken as an example for description, the corresponding first wind direction is from bottom to top, and the second wind direction is from top to bottom. If the air conditioner is used for air outlet in other directions, correspondingly, the first air direction and the second air direction are adaptively changed according to the air outlet direction. For example, the air conditioner is a front air outlet, the first air direction is a direction from back to front, the second air direction is a direction from front to back, and the change of the air direction is still adjusted by the difference of the rotation directions of the fans.

Fig. 10 is a schematic structural diagram of an embodiment of a heat dissipation apparatus for an air conditioner according to the present invention, which includes a sampling temperature acquisition unit 101, a sampling temperature comparison unit 102, and a control unit 103, in addition to a heat sink for dissipating heat from a heat generating device. The functions and the connection relationship among the units are described as follows:

the sampling temperature acquiring unit 101 is used for acquiring the sampling temperature of the radiator. And a more preferable sampling temperature acquisition mode is described in the above method embodiment.

The sampling temperature comparing unit 102 is configured to compare the sampling temperature acquired by the sampling temperature acquiring unit 101 with a set temperature threshold.

The control unit 103 is at least used for controlling the wind direction of the radiator in the wind field to be kept in the first wind direction to operate when the sampling temperature comparison unit 101 compares that the sampling temperature is not greater than the set temperature threshold; and the sampling temperature comparison unit 101 is further configured to control the wind direction in the wind field in which the radiator is located to change to a second wind direction for operation when the sampling temperature is compared to be greater than the set temperature threshold value, where the second wind direction is opposite to the first wind direction. The wind direction of the heat radiator in the wind field is changed by controlling the rotation direction of the fan.

In other embodiments, the heat dissipation control device further includes an exhaust pressure obtaining unit and a set operation time determining unit. The exhaust pressure obtaining unit is at least used for obtaining the exhaust pressure of the air conditioner in the process that the control unit 103 controls the wind direction in the wind field where the radiator is located to change to the second wind direction for operation. And a set operation time determination unit for determining the set operation time in real time based on the sampling temperature acquired by the sampling temperature acquisition unit 101 and the exhaust pressure acquired by the exhaust pressure acquisition unit. In these embodiments, the control unit 103 is further configured to start timing from controlling the wind direction in the wind field in which the heat sink is located to change to the second wind direction, and control the wind direction in the wind field in which the heat sink is located to change to the first wind direction when the timing reaches the set operation time determined by the set operation time determination unit. A more preferable method for determining the set operation time is described in the above method embodiment.

The air conditioner heat dissipation device of each embodiment operates a corresponding software program, and heat dissipation of the air conditioner is realized according to the process of the method embodiment, and the technical effects are described with reference to the method embodiment.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof; such modifications and substitutions do not depart from the spirit and scope of the corresponding claims.

Claims

1. A heat dissipation method of an air conditioner is characterized by comprising the following steps:

acquiring the sampling temperature of a radiator for radiating heat of a heating device of an air conditioner; comparing the sampling temperature with a set temperature threshold;

when the sampling temperature is not greater than the set temperature threshold value, controlling the wind direction of the radiator in the wind field to be kept in a first wind direction for operation; when the sampling temperature is larger than the set temperature threshold value, controlling the wind direction of the wind field in which the radiator is located to change to a second wind direction for operation; the second wind direction is opposite to the first wind direction;

the sampling temperature is Tfin, and Tfin is determined by the following method:

Tfin=a*TA+b*TB；

wherein, a, b are set coefficients, satisfy: a + b =1 and is determined according to the positions of the heat generating device and the heat sink; TA and TB are the real-time temperature of the lower near wind end and the far wind end of the first wind respectively.

2. The method for dissipating heat from an air conditioner according to claim 1, further comprising:

and starting timing from controlling the wind direction in the wind field in which the radiator is positioned to be changed into a second wind direction, and controlling the wind direction in the wind field in which the radiator is positioned to be changed into the first wind direction when the timing time reaches the set operation time.

3. The heat dissipation method of claim 2, wherein the set operation time is determined by:

acquiring the exhaust pressure of the air conditioner in the process of controlling the wind direction in the wind field where the radiator is located to be changed into a second wind direction for operation;

and determining the set operation time in real time according to the sampling temperature and the exhaust pressure.

4. The air conditioner heat dissipation method according to claim 3, wherein the determining the set operation time in real time according to the sampling temperature and the exhaust pressure specifically comprises:

t＝Kp×{⊿Tfin(n)－⊿Tfin(n-1)}＋Ki×⊿Tfin(n)×DT ＋Kd×{⊿Tfin(n)－2×⊿Tfin(n-1)＋⊿Tfin(n-2)}/DT

-Ks×{⊿Pd(n)－⊿Pd(n-1) }

in which (delta Tfin (n) = Tfin (n) -Tdo, (n-1) = Tfin (n-1) -Tdo),

⊿Tfin(n-2)=Tfin(n-2)－Tdo，⊿Pd(n)=Pd(n)－Pdo,

⊿Pd(n-1)=Pd(n-1)－Pdo,

wherein n is sampling time, Tfin is the sampling temperature, Tdo is the known protection temperature of the heating device, Pd is the exhaust pressure, Pdo is the known protection pressure, Kp, Ki, Kd, Ks are the known PID control coefficients, and DT is the control period.

5. The utility model provides an air conditioner heat abstractor, includes for the radiating radiator of device that generates heat, its characterized in that, the device still includes:

the sampling temperature acquisition unit is used for acquiring the sampling temperature of the radiator; the sampling temperature comparing unit is used for comparing the sampling temperature acquired by the sampling temperature acquiring unit with a set temperature threshold;

the control unit is at least used for controlling the wind direction of the heat radiator in the wind field to be kept in a first wind direction to operate when the sampling temperature is not larger than the set temperature threshold; the sampling temperature is higher than the set temperature threshold value, and the wind direction of the wind field in which the radiator is located is controlled to change to a second wind direction for operation; the second wind direction is opposite to the first wind direction;

the sampling temperature is Tfin, and the sampling temperature acquisition unit determines Tfin by adopting the following method:

Tfin=a*TA+b*TB；

6. The heat sink device according to claim 5, wherein the control unit is further configured to start timing from controlling the wind direction in the wind field where the heat sink is located to change to a second wind direction, and control the wind direction in the wind field where the heat sink is located to change to the first wind direction when the timing time reaches a set operation time.

7. The air conditioner heat sink device according to claim 6, further comprising:

the exhaust pressure acquisition unit is at least used for acquiring the exhaust pressure of the air conditioner in the process that the control unit controls the wind direction in the wind field where the radiator is located to change into the second wind direction for operation;

and the set operation time determining unit is used for determining the set operation time in real time according to the sampling temperature and the exhaust pressure.

8. An air conditioner including a heat generating device, characterized by further comprising the air conditioner heat dissipating apparatus of any one of the above claims 5 to 7.