JP2009210229A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner capable of preventing a temperature rise of electrical equipment by suppressing a temperature of a compressor by the control of an expansion valve on the basis of an operation current and the temperature of the compressor. <P>SOLUTION: The air conditioner has a compressor temperature detecting means, an operation current detecting means, and an expansion valve opening changing means. By changing a predetermined expansion valve opening by an expansion valve opening changing means and carrying out electrical equipment temperature rise protection operation according to the operation current detected by the operation current detecting means and the compressor temperature detected by the compressor temperature detecting means, the temperature of the compressor can be lowered, and by reducing thermal radiation from the compressor, the temperature rise of the electrical equipment can be prevented, and the protection of the electrical equipment can be carried out. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an air conditioner that controls an expansion valve according to an operating current and a compressor temperature.

  Conventionally, this type of air conditioner has a control that suppresses an increase in the temperature of the electrical component by limiting the upper limit of the operating current detected by the operating current detecting means corresponding to the outdoor air temperature detected by the outdoor air temperature detecting means. (For example, see Patent Document 1).

  FIG. 5 shows a block diagram of a conventional air conditioner described in Patent Document 1. As shown in FIG. As shown in FIG. 5, the main body control unit 13, the outside air temperature sensor 18, and the compressor 9 are configured. The main body control unit 13 further includes an operating current detection unit 12, a central control unit 15, and a compressor. It comprises a control unit 19 and a table storage unit 16.

The operating current detected by the operating current detecting means 12 and the outdoor temperature detected by the outside air temperature sensor 18 are transmitted to the central control unit 15, and the central control unit 15 stores these information and the table storage unit 16 in advance. As a result of comparing the detected reference temperature with the predetermined reference temperature related to the outdoor temperature and the detected reference current related to the operating current, the outdoor temperature is equal to or higher than the reference temperature and the operating current is equal to or higher than the reference current. The central control unit 15 transmits a signal for lowering the compressor frequency to the compressor control unit 19, and the compressor 9 operates at the frequency of the compressor control unit 19. Thereby, when outdoor temperature is more than reference temperature, control which controls the temperature rise of an electrical component by restricting operation current to below reference current has been performed.
JP 2002-106924 A

  However, in the conventional configuration, the structure of the outdoor unit is as shown in FIG. 6, and the outdoor unit 2 is a fan room in which an outdoor heat exchanger 6 (not shown) and an outdoor fan 11 are housed. 20 and a machine room 21 are partitioned by a partition plate 22. The machine room 21 has an outdoor refrigerant circuit component such as a compressor 9, a four-way valve 4 (not shown), an expansion valve 7 (not shown), etc. constituting the refrigerant circuit, and an electrical component above the outdoor refrigerant circuit component. 3 is provided. Therefore, even if the operating current is limited as in the conventional control described above, when the temperature of the compressor 9 is high, such as during overload operation, the electrical component 3 is affected by the radiant heat of the compressor 9, and the electrical component 3 There is a problem that there is a risk of destruction due to exceeding the allowable temperature.

  Recently, the opportunity to install the outdoor unit 2 in a narrow place such as a veranda has been increased, and it has become difficult to secure the installation space for the outdoor unit 2, so the demand for a compact outdoor unit has increased. . Therefore, in order to make the compact outdoor unit more compact in the height direction, the distance between the compressor 9 and the electrical component 3 (see arrow A) is reduced, and the problem that it becomes more easily affected by the heat radiation of the compressor 9 is a problem. Had.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide an air conditioner that can prevent an increase in the temperature of electrical components by suppressing the temperature of the compressor.

In order to solve the conventional problem, an air conditioner of the present invention is an air conditioner having compressor temperature detecting means, operating current detecting means, and expansion valve opening changing means, wherein the operating current is According to the operating current detected by the detecting means and the compressor temperature detected by the compressor temperature detecting means, the expansion valve opening changing means is changed to a predetermined expansion valve opening and the electrical component temperature rise protection operation is performed. Is.

  As a result, the temperature of the compressor can be lowered, and by reducing the heat radiation from the compressor, it is possible to prevent an increase in the temperature of the electrical component, thereby protecting the electrical component.

  The air conditioner of the present invention can provide a highly reliable air conditioner with less defects because it can prevent the temperature rise of electrical components by reducing heat radiation from the compressor. .

  The first invention is an air conditioner having compressor temperature detecting means, operating current detecting means, and expansion valve opening changing means, wherein the operating current detected by the operating current detecting means and the compressor temperature According to the compressor temperature detected by the detecting means, the temperature of the compressor can be lowered by changing to a predetermined expansion valve opening by the expansion valve opening changing means and performing an electrical component temperature rise protection operation. By reducing the heat radiation from the compressor, it is possible to prevent an increase in the temperature of the electrical component, thereby protecting the electrical component.

  In the second invention, in particular, the compressor temperature detected by the compressor temperature detecting means is predetermined when the time measured by the time measuring means exceeds the predetermined time. By changing the expansion valve opening degree by the expansion valve opening changing means until the temperature becomes lower than the temperature, it is possible to protect the electrical component with high reliability by performing more appropriate control according to the load.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

(Embodiment 1)
FIG. 1 shows a refrigeration cycle diagram of an air conditioner according to a first embodiment of the present invention.

  In FIG. 1, the air conditioner generally includes an indoor unit 1 disposed in a space to be air-conditioned, an outdoor unit 2 disposed outdoors, and a heat medium circulation path. The indoor unit 1 includes an indoor heat exchanger 4 and an indoor fan 5 capable of adjusting the air volume. The outdoor unit 2 includes an outdoor heat exchanger 6, an expansion valve 7 that changes the pressure of the heat medium, cooling operation and heating operation. The four-way valve 8 that switches the flow of the heat medium, the compressor 9 that compresses the heat medium, the compressor sensor 10 that is a compressor temperature detecting means, and the outdoor fan 11 that can adjust the air volume.

  Furthermore, the outdoor unit 2 includes a main body control unit 13 that controls the air conditioner based on the compressor temperature detected by the compressor sensor 10 and the information on the operating current detected by the operating current detection means 12.

  FIG. 2 is a block diagram showing a control circuit of the air conditioner according to the first embodiment of the present invention.

In FIG. 2, the main body control unit 13 measures the operating current (A) detected by the operating current detecting means 12, the compressor temperature (CompT) detected by the compressor sensor 10, and the timer 14 which is a timing means. Information is transmitted to the central control unit 15, and the central control unit 15 performs expansion valve opening degree changing means 17 based on the information and information on the expansion valve opening degree (Evpls) stored in advance in the table storage unit 16. It is comprised so that the opening degree of the expansion valve 7 may be changed.

  FIG. 3 is a control flowchart of the air conditioner according to the first embodiment of the present invention.

  With reference to the flowchart of FIG. 3, a procedure for controlling the expansion valve opening degree (Evpls) by the central control unit 15 based on the input information and the information stored in the table storage unit 16 at the start of operation will be described. .

  When the air conditioner is operated, an operation start signal is transmitted to the central control unit 15 (step S1). When the central control unit 15 detects the input of the operation start signal, the central control unit 15 starts the air conditioning operation by driving the compressor 9, the outdoor fan 11, the four-way valve 8 and the like via the operation control unit (not shown). The operation start signal is transmitted to the central control unit 15, and the central control unit 15 that has received this information detects the operation current (A) by the operation current detection means 12 (step S2).

  In step S3, the central control unit 15 compares the operating current (A) detected in step S2 with information of a predetermined reference current (A1) stored in advance in the table storage unit 16, and the reference current (A1 ) If so, the process proceeds to step S4, and if less than the reference current (A1), the process returns to step S2.

  In step S4, the central control unit 15 detects the compressor temperature (CompT) by the compressor sensor 10, and in step S5, the set value for protecting the temperature rise of the electrical components stored in the table storage unit 16 in advance ( Compared with the information of CompT1), if it exceeds the set value (CompT1), it is determined that there is a need for protection of the electrical component temperature rise, and the routine proceeds to step 6 where the expansion valve opening changing means 17 stores the table storage 16 in advance. A signal for opening the opening of the expansion valve by the stored predetermined value is transmitted, and the electrical component protection control loop is terminated in step S7.

  As described above, in the control flow from Step 1 to Step 7, the electrical component temperature rise protection operation is performed. For example, when the predetermined reference current (A1) is 13.0 A or more as a prescribed value in the microcomputer memory and the set value (CompT1) for protection of electrical component temperature rise is 100 ° C. or more, the expansion valve opening is 30 pulses. By opening, the temperature of the compressor can be lowered, and by reducing the heat radiation from the compressor, the temperature rise of the electrical component 3 can be prevented and the electrical component 3 can be protected. it can.

(Embodiment 2)
FIG. 4 is a control flowchart of the air conditioner according to the second embodiment of the present invention.

  The control of Embodiment 2 will be described using the flowchart of FIG. Note that steps S11 to S14 in FIG. 4 perform the same operations as steps S1 to S4 of the first embodiment, and thus description thereof is omitted.

  In step S14, the central control unit 15 detects the compressor temperature (CompT) by the compressor temperature sensor. In step S15, the central control unit 15 detects a set value (preliminarily stored in the table storage unit 16 for protection of electrical component temperature rise). Compared with the information of CompT1), if the set value (CompT1) is equal to or greater than this, it is determined that there is a need for protection of the electrical component temperature rise, and the process proceeds to step 16.

In step S 16, the expansion valve opening changing means 17 transmits a signal for opening the expansion valve opening by a predetermined value stored in advance in the table storage unit 16. In step 17, the central control unit 15 measures the time with the timer 14. The detected time (t1) is compared with a predetermined reference time (ts, for example, 5 minutes) related to the time (ts) stored in advance as the time (t1).
When 1) exceeds the reference time (ts, for example, 5 minutes), the process proceeds to step S18, the compressor temperature sensor 10 detects the compressor temperature (CompT) again, and the electrical component temperature rise protection is performed in step S19. If it is equal to or less than the set value (CompT1), the electrical component protection control loop ends in step S20. If it is not less than the set value (CompT1) for protecting the electrical component temperature rise in step S19, the processing of step S16 to step S19 is repeated.

  By repeatedly detecting the temperature of the compressor 9 as described above, it is possible to protect the electrical component with high reliability by performing more appropriate control according to the load.

  As described above, the air conditioner according to the present invention can prevent an increase in the temperature of electrical components by reducing heat radiation from the compressor, so that the air conditioner has high reliability and less defects for the user. Therefore, in addition to an air conditioner, it can be applied to uses such as a dehumidifier, a refrigeration apparatus, and a heat-pong water heater.

Refrigeration cycle diagram of the air conditioner in Embodiment 1 of the present invention The block diagram which shows the control circuit of the air conditioner in Embodiment 1 of this invention Control flow chart of air conditioner in Embodiment 1 of the present invention Control flow chart of air conditioner in Embodiment 2 of the present invention Block diagram of a conventional air conditioner Partially broken front view of a conventional air conditioner outdoor unit

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Indoor unit 2 Outdoor unit 3 Electrical component 4 Indoor heat exchanger 5 Indoor fan 6 Outdoor heat exchanger 7 Expansion valve 8 Four-way valve 9 Compressor 10 Compressor temperature sensor 11 Outdoor fan 12 Operating current detection means 13 Main body control part 14 Timer DESCRIPTION OF SYMBOLS 15 Central control part 16 Table memory | storage part 17 Expansion valve opening change means 18 External temperature sensor 19 Compressor control part 20 Blower room 21 Machine room 22 Partition plate

Claims (2)

An air conditioner having compressor temperature detecting means, operating current detecting means, and expansion valve opening changing means, wherein the operating current detected by the operating current detecting means and detected by the compressor temperature detecting means An air conditioner that performs an electric component temperature rise protection operation by changing the expansion valve opening degree changing means to a predetermined expansion valve opening degree according to the compressor temperature. The expansion valve opening degree changing means by the expansion valve opening degree changing means until the compressor temperature detected by the compressor temperature detecting means falls below a predetermined temperature every time the time measured by the time measuring means elapses over a predetermined time. The air conditioner according to claim 1, wherein the air conditioner is changed.