JPH08114346A - Air-conditioning machine - Google Patents

Abstract

PURPOSE: To permit preheating operation without consuming an electric power more than necessitated by a method wherein the preheating amount of a preheater is increased when an outdoor temperature is low but the preheating amount of the preheater is reduced when the outdoor temperature is high. CONSTITUTION: An outdoor temperature sensor 4 detects an outdoor temperature and a preheating amount operating unit 3a operates the preheating amount of a preheater 2 so that the preheating amount becomes big when an outdoor temperature, detected by the outdoor temperature sensor 4, is low but the same operating unit 3a operates so that the preheating amount becomes small when the outdoor temperature is high. A preheater control unit 3b controls the preheating amount of the preheater 2 so as to obtain the preheating amount operated by the preheating amount operating unit 3a. Accordingly, the preheater 2 can preheat a compressor 1 with the optimum preheating amount by the preheater control unit 3b. According to this method, preheating operation, which will never consume an electric power more than necessitated, can be effected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner which performs a preheating operation for preheating a compressor while the operation is stopped.

[0002]

2. Description of the Related Art Conventionally, some air conditioners include a preheat heater for preheating a compressor. As shown in the flowchart of FIG. 5, this air conditioner performs a preheating operation process while the operation is stopped.

First, in step S21, the outdoor temperature T _OA is detected by the outdoor temperature sensor. Next, in step S22, preheat determination, that is, it is determined whether the outdoor temperature T _OA is lower than the predetermined temperature T. Then, when it is determined in step S22 that the outdoor temperature T _OA is lower than the predetermined temperature T, the process proceeds to step S23, and the preheat heater is turned on. On the other hand, when it is determined in step 2 that the outdoor temperature T _OA is _equal to or higher than the predetermined temperature T, the process proceeds to step S24, and the preheat heater is turned off.

As described above, in the air conditioner, when the outdoor temperature T _OA is lower than the predetermined temperature T, it is judged that the compressor is at a low temperature, the preheat heater is turned on, and the temperature of the compressor is turned on. Raise. Therefore, it is possible to prevent the temperature of the compressor from lowering and the temperature of the compressor to be low during the stoppage of the operation, so that the refrigerant is accumulated in the compressor and the lubricating oil is diluted.

[0005]

In the air conditioner, even if the temperature of the compressor is sufficiently high after the preheat heater is turned on when the outdoor temperature T _OA is lower than the predetermined temperature T,
Since the temperature of the compressor cannot be detected, there is a drawback in that the preheater continues to be in the ON state and power is consumed.

Further, the preheating amount of the preheating heater must be set under the condition where the outdoor temperature is the severest, and there is a problem that power is consumed more than necessary when the outdoor temperature is not so low.

Therefore, an object of the present invention is to provide an air conditioner capable of preheating operation without consuming more power than necessary.

[0008]

In order to achieve the above object, the air conditioner of claim 1 is an air conditioner equipped with preheating means for preheating a compressor, and an outdoor temperature detecting means for detecting an outdoor temperature. The preheating amount of the preheating means is calculated so as to increase when the outdoor temperature detected by the outdoor temperature detecting means is low, and the preheat amount calculating means that decreases when the outdoor temperature is high, And a preheat amount control unit for adjusting the preheat amount of the preheat unit to the preheat amount calculated by the preheat amount calculating unit.

The air conditioner according to claim 2 is an air conditioner having preheating means for preheating the compressor, wherein the outdoor temperature detecting means for detecting the outdoor temperature and the ON time t _ON and OFF of the preheating means. The time t _OFF is calculated so that the ratio t _ON / t _OFF between the on time t _ON and the off time t _OFF becomes large when the outdoor temperature detected by the outdoor temperature detecting means is low, while the above An on / off time calculating means for calculating so that the ratio t _ON / t _{OFF of the} on time t _ON and the off time t _OFF becomes small when the outdoor temperature is high, and the on time t calculated by the on / off time calculating means.
_{On /} off control means for _turning on / off the preheating means based on _ON and the off time t _OFF is provided.

[0010]

According to the air conditioner of the first aspect, the outdoor temperature detecting means detects the outdoor temperature, and the preheating calculating means detects the preheating amount of the preheating means by the outdoor temperature detecting means. It is calculated such that it becomes large when the outdoor temperature is low, and it becomes small when the outdoor temperature is high. The preheating control means adjusts the preheating amount of the preheating means so that the preheating amount calculated by the preheating amount calculating means becomes equal to the preheating amount. Therefore, the preheating means compresses the preheating amount with an appropriate preheating amount by the preheating amount controlling means. The machine can be preheated.
Therefore, when the outdoor temperature is low, the preheating amount of the preheating means is increased, while when the outdoor temperature is high, the preheating amount of the preheating means is decreased, so that the compressor can be brought to an appropriate temperature at the time of starting.

Therefore, the power consumed by the preheating means can be saved. Further, since the compressor is preheated to an appropriate temperature at the start of operation, the refrigerant is not accumulated in the compressor even when the temperature is low outside the room, and the lubricating oil can be prevented from being diluted. Therefore, in the case of the inverter type compressor, even if the rotation frequency at startup is quickly increased,
Since the compressor does not become insufficiently lubricated, the start-up at the start of operation is improved.

According to the air conditioner of the second aspect, the outdoor temperature detecting means detects the outdoor temperature, and the on / off time calculating means is based on the outdoor temperature detected by the outdoor temperature detecting means. , ON time of preheating means t _ON
And off time t _OFF are calculated. Then, based on the on time t _ON and the off time t _OFF calculated by the on / off time calculating means, the preheating operation control means turns the preheating means on and off to preheat the compressor. That is, when the outdoor temperature is low, the ratio t _ON / t _OFF of the on time t _ON and the off time t _OFF is increased to increase the amount of preheating of the preheating means, and when the outdoor temperature is high, the on time t ON.
By reducing the ratio t _ON / t _OFF of the _ON and OFF time t _OFF, it is to reduce the preheating amount of the preheating means. Therefore, the preheating of the compressor can be appropriately performed by adjusting the preheating amount of the preheating means to be large or small according to the outdoor temperature being low or high.

Therefore, the power consumed by the preheating means can be saved. Further, since the compressor is preheated to an appropriate temperature at the start of operation, the refrigerant is not accumulated in the compressor even when the temperature is low outside the room, and the lubricating oil can be prevented from being diluted. Therefore, in the case of the inverter type compressor, even if the rotation frequency at startup is quickly increased,
Since the compressor does not become insufficiently lubricated, the start-up at the start of operation is improved.

[0014]

EXAMPLES The air conditioner of the present invention will be described in detail below with reference to examples.

(First Embodiment) FIG. 1 is a block diagram of the essential parts of an air conditioner according to a first embodiment of the present invention, in which 1 is a compressor, 2 is a preheater for preheating the compressor 1, Reference numeral 3 denotes a preheat amount calculation unit 3a as a preheat amount calculation unit for calculating the preheat amount of the preheat heater 2 and a preheat amount control unit for controlling the preheat heater 2 based on the preheat amount calculated by the preheat amount calculation unit 3a. The control unit 4 including the preheater heater control unit 3b is an outdoor temperature sensor as an outdoor temperature detecting unit. The control unit 3 has a microcomputer (hereinafter referred to as a microcomputer) and an input / output circuit, and the preheat amount calculation unit 3a and the preheat heater control unit 3b are configured by software of the microcomputer.

In the above structure, the control unit 3 performs the preheating operation shown in the flowchart of FIG. 3 while the operation is stopped. Less than,
The process of the preheating operation will be described with reference to the flowchart of FIG. The preheating operation process during the stop of operation is performed every predetermined time.

First, in step S1, the outdoor temperature sensor 4 detects the outdoor temperature T _OA . Next, in step S2, preheat determination, that is, it is determined whether the outdoor temperature T _OA detected in step S1 is lower than a predetermined temperature T. And step S
If the outdoor temperature T _OA is less than the predetermined temperature T in step 2, step S
On the other hand, when the outdoor temperature T _OA is equal to or higher than the predetermined temperature T while proceeding to 3,
In step S5, the preheat heater controller 3b turns off the preheat heater 2.

Next, in step S3, the preheat amount calculation unit 3a sets the preheat amount of the preheat heater 2, that is, the heater power, based on the outdoor temperature T _OA . That is, when the outdoor temperature T _OA is low, the preheat amount is calculated to be large, while when the outdoor temperature T _OA is high, the preheat amount is calculated to be small. Next, the process proceeds to step S4, the preheat heater 2 is turned on, and this process ends. Then, after a lapse of a predetermined time, this process is repeated from step S1.

In this way, the compressor 1 is preheated by the preheater 2 while the operation is stopped so that the refrigerant is not accumulated in the compressor 1 and the lubricating oil in the compressor 1 is prevented from being diluted. Then, according to the high outdoor temperature T _OA ,
By increasing or decreasing the amount of preheating of the preheating heater 2, preheating operation for optimally controlling the power consumption of the preheating heater 2 can be performed.

Therefore, the power consumed by the preheater 2 can be saved. In addition, since the compressor 1 can be preheated to an appropriate temperature during the operation stop and the refrigerant is prevented from being accumulated in the compressor 1 to dilute the lubricating oil, the compressor 1 becomes insufficiently lubricated at the start of the operation. There is no. Therefore, when the present invention is applied to the inverter type air conditioner, the lubricating oil does not run short at the time of startup, so that the operating frequency can be quickly raised.

(Second Embodiment) FIG. 2 is a block diagram showing the essential parts of an air conditioner according to a second embodiment of the present invention, which has the same structure as that of the first embodiment except for the control unit. The same components are given the same reference numerals and the description thereof will be omitted. In FIG.
The controller 5 calculates the on-time t _ON and the off-time t _{OFF of} the preheater heater 2 based on the outdoor temperature T _OA detected by the outdoor temperature sensor 7, and an on-off time calculator 5a as an on-off time calculator and a preheater. A preheating heater control section 5b as an on / off control means for turning on / off the heater 2 is provided. The control unit 5 has a microcomputer and an input / output circuit, and the on / off time calculation unit 5a and the preheat heater control unit 5b are configured by software of the microcomputer. The preheat amount of the preheat heater 2 is set to be substantially constant.

In the above structure, the control unit 5 performs the preheating operation shown in the flowchart of FIG. 4 while the operation is stopped. Less than,
The process of the preheating operation will be described with reference to the flowchart of FIG. Note that this preheating operation process is repeatedly performed while the operation is stopped.

First, in step S11, the outdoor temperature sensor 4
Detects the outdoor temperature T _OA . Next, step S12
Preheat determination, that is, it is determined whether the outdoor temperature T _OA is lower than the predetermined temperature T. The outdoor temperature T _OA is _equal to the predetermined temperature T
If it is determined to be less than, while proceeding to step S13,
When it is determined that the outdoor temperature T _OA is _equal to or higher than the predetermined temperature T, this process ends.

Next, in step S13, the outdoor temperature T _{OA is set.}
Based on the above, the ON time t _ON and the OFF time t of the preheating heater 2 are
Set to _OFF . That is, the on / off time calculation unit 5a
Is the on time t _ON and the off time t when the outdoor temperature T _OA is low.
On-time t _ON so that the ratio t _ON / t _OFF the _OFF increases
And the off time t _OFF , the ratio of the on time t _ON to the off time t _OFF is t _ON / t _OFF when the outdoor temperature T _OA is high.
The on time t _ON and the off time t _OFF are calculated so that becomes smaller.

Then, in step S14, the preheat heater controller 5b turns on the preheat heater 2 and proceeds to step S15, where the elapsed time t ₁ after turning on the preheat heater 2 is step S1.
It is determined whether or not it is longer than the ON time t _ON obtained in 13. Then, the elapsed time t ₁ at step S15 determines that the larger the on-time t _ON, the flow returns to step S14.
On the other hand, if it is determined in step S15 that the elapsed time t ₁ is equal to or greater than the _ON time t _ON , the process proceeds to step S16.

Next, in step S16, the preheat heater control unit 5b turns off the preheat heater 2 and proceeds to step S17. The elapsed time t ₂ after turning off the preheat heater ₂ is step S2.
It is determined whether or not it is longer than the off time t _OFF obtained in 13. Then, when it is determined in step S17 that the elapsed time t ₂ is longer than the off time t _OFF , the process returns to step S16. On the other hand, in step S17, the elapsed time t ₂ is the off time t
_If it is determined that the value is _OFF or more, this process ends. Then, after a lapse of a predetermined time, this process is repeated from step S11.

In this way, the compressor 1 is preheated by the preheater 2 while the operation is stopped so that the refrigerant is not accumulated in the compressor 1 and the lubricating oil in the compressor 1 is prevented from being diluted. You can When the outdoor temperature T _OA is lower than the predetermined temperature T, the preheating heater 2 is repeatedly turned on and off, and the ratio t of the on time t _ON to the off time t _OFF is changed according to the outdoor temperature T _OA.
By adjusting _ON / t _OFF , the preheating operation for optimally controlling the power consumption of the preheating heater 2 can be performed.

Therefore, the power consumed by the preheater 2 can be saved. Further, the compressor 1 is preheated to an appropriate temperature when the operation is stopped, and the refrigerant is prevented from being accumulated in the compressor to dilute the lubricating oil. Therefore, the compressor 1 does not become insufficiently lubricated at the start of the operation. Therefore, when the present invention is applied to the inverter type air conditioner, the lubricating oil does not run short at the time of startup, so that the operating frequency can be quickly raised.

In the first and second embodiments, the air conditioner does not have a temperature sensor for detecting the temperature of the compressor, but the air conditioner has a temperature sensor for detecting the temperature of the compressor. Of course, this invention may be applied.

In the second embodiment, the ratio t _ON / t _{OFF of the} on-time t _ON and the off-time t _OFF depends on the outdoor temperature T _OA.
Although the ON / OFF of the preheating heater 2 is repeated, it is also possible to calculate only the _ON time t _ON and turn _{ON the} preheating heater 2 for _ON time t _ON at intervals of a predetermined time t.
In this case, the off time _tOFF is (t- _tON ).

[0031]

As is apparent from the above, in the air conditioner of the first aspect of the invention, the outdoor temperature detecting means detects the outdoor temperature, and the preheat amount calculating means preheats the compressor. Is calculated so that it increases when the outdoor temperature detected by the outdoor temperature detecting means is low, and decreases when the outdoor temperature is high, and the preheat amount control means calculates by the preheat amount calculating means. The preheating amount of the preheating means is adjusted to the preheat amount thus obtained.

Therefore, according to the air conditioner of the invention of claim 1, the power consumed by the preheating means can be saved. Further, since the compressor is preheated to an appropriate temperature at the start of operation, the refrigerant is not accumulated in the compressor even when the outdoor temperature is low, and the lubricating oil can be prevented from being diluted. Therefore, when an inverter type compressor is used, the compressor will not run out of lubrication even if the rotation frequency is quickly started and started when the outdoor temperature is low, so improve the startup at the start of operation. You can

Further, in the air conditioner of the second aspect of the invention, the outdoor temperature detecting means detects the outdoor temperature, and the on / off time calculating means the on time t _{ON of} the preheating means for preheating the compressor.
And the off time t _{OFF so} that the ratio t _ON / t _OFF between the on time t _ON and the off time t _OFF of the preheating means becomes large when the outdoor temperature detected by the outdoor temperature detecting means is low. When the outdoor temperature is high, the ratio t _ON / t _{OFF of the} on-time and the off-time is calculated to be small, and based on the on-time t _ON and the off-time t _OFF calculated by the on-off time calculating means. The on / off control means turns on / off the preheating means.

Therefore, according to the air conditioner of the second aspect of the present invention, when the outdoor temperature is low, the ratio t _ON / t _OFF of the on time t _ON and the off time t _OFF is increased to preheat the preheating means. While increasing the amount, when the outdoor temperature is high, the ratio t _ON / t _OFF of the on time t _ON and the off time t _OFF is decreased,
Reduce the amount of preheating of the preheating means. Therefore, the power consumed by the preheating means can be saved. Further, since the compressor is preheated to an appropriate temperature at the start of operation, the refrigerant is not accumulated in the compressor even when the outdoor temperature is low, and the lubricating oil can be prevented from being diluted. Therefore, when an inverter type compressor is used, the compressor will not run out of lubrication even if the rotation frequency is quickly started and started when the outdoor temperature is low, so improve the startup at the start of operation. You can

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of an air conditioner according to a first embodiment of the present invention.

FIG. 2 is a main part configuration diagram of an air conditioner of a second embodiment of the present invention.

FIG. 3 is a flowchart showing a preheating operation process of a control unit of the air conditioner of the first embodiment.

FIG. 4 is a flowchart showing a preheating operation process of a control unit of the air conditioner of the second embodiment.

FIG. 5 is a flowchart showing a preheating operation process of a conventional air conditioner.

[Explanation of symbols]

1 ... Compressor, 2 ... Preheat heater, 3, 5 ... Control part, 3a ... Preheat amount calculation part, 3b, 5b ... Preheat heater control part, 4 ... Preheat heater, 5a ... On / off time calculation part.

Claims (2)

[Claims] 1. A preheating means for preheating the compressor (1) In the air conditioner having a (2), the outdoor temperature detecting means for detecting the outdoor temperature (T _OA) (4), said preheating means (2) The amount of preheat of the
Preheat amount calculating means (3a) for calculating so as to increase when the outdoor temperature (T _OA ) detected by (4) is low, and to decrease when the outdoor temperature (T _OA ) is high
And the preheating amount of the preheating means (2) is calculated as the preheating amount calculation means (3a).
Preheat amount control means for adjusting the preheat amount calculated by
An air conditioner comprising (3b). 2. A preheating means for preheating the compressor (1) In the air conditioner having a (2), the outdoor temperature detecting means for detecting the outdoor temperature (T _OA) (4), said preheating means (2) of the on-time t _oN and oFF time t _oFF, the ratio between the oN time t _oN and the off time t _oFF when the detected the outdoor temperature (T _OA) is lower by the outdoor temperature detecting means (4) t _ON / t _OFF is calculated to be large, while when the outdoor temperature (T _OA ) is high, the on time t _ON
The off-on-off time calculating means the ratio t _ON / t _OFF the time t _OFF is calculated to be smaller and (5a), the on-off time calculating means (5a) the on-time t _ON and the off calculated by the An air conditioner comprising: an on / off control means (5b) for _turning on and _{off the} preheating means (2) based on time t _OFF .