JP2001304664A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner, in which the outlet temperature of an indoor unit will not vary significantly and high pressure cut does not act during control operation. SOLUTION: An air conditioner, comprising a plurality of indoor units 3 connected with an outdoor unit 1 mounting a variable capacity compressor, is provided with an operation control means 16 for estimating the load of an operating indoor unit 3 upon thermo-off based on the temperature difference between inlet and outlet temperature at the moment of thermo-off and the velocity of outlet air, calculating the sum of an estimated load and the load of other operating indoor unit 3, altering the capacity of the variable capacity compressor 11, based on the calculated sum load and operating the outdoor unit for a prescribed, time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner having a plurality of outdoor units, and to an operation control of each outdoor unit.

[0002]

2. Description of the Related Art In general, there is known an air conditioner in which a plurality of outdoor units are connected in parallel to an inter-unit pipe extending from an indoor unit. In this type, it is common to control the compressor rotation speed of the outdoor unit based on the capacity of the indoor unit and the coil temperature of the indoor heat exchanger.

[0003]

However, if the rotational speed of the compressor of the outdoor unit is controlled based on the coil temperature of the indoor heat exchanger as in the prior art, the follow-up of the temperature becomes poor, In particular, there is a problem that the blowout temperature greatly changes and gives an unpleasant feeling.

In the above control, there is a problem that the followability to the air-conditioning load is poor, the pressure in the refrigerant circuit becomes abnormal, and an emergency stop due to a so-called high-pressure cut occurs.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to prevent the blowout temperature of the indoor unit from largely changing during operation control, and to prevent the high-pressure cut from working. An object of the present invention is to provide an air conditioner.

[0006]

According to the first aspect of the present invention,
In an air conditioner in which a plurality of indoor units are connected to an outdoor unit equipped with a variable capacity compressor, when an operating indoor unit is thermo-off, the suction temperature and the blow-out temperature of the indoor unit at the time of thermo-off Temperature difference,
And the load at the time of thermo-off of the indoor unit is estimated based on the wind speed of the blown air, and the total value of the estimated load and the load of the other indoor units during operation is calculated, based on the calculated total load. And an operation control means for operating the outdoor unit for a predetermined time by changing the capacity of the variable capacity compressor.

According to a second aspect of the present invention, in an air conditioner in which a plurality of indoor units are connected to an outdoor unit having a variable capacity compressor, when the stopped indoor unit is thermo-on, the indoor unit is stopped. Estimate the load of the indoor unit at the time of thermo-on by multiplying the load factor of the entire system at the time of thermo-on by the capacity of the indoor unit. An operation control means for calculating a value, changing the capacity of the variable capacity compressor based on the calculated total load, and operating the outdoor unit for a predetermined time is provided.

According to a third aspect of the present invention, in an air conditioner in which a plurality of indoor units are connected to an outdoor unit equipped with a variable capacity compressor, the operating indoor unit is thermo-off and the stopped indoor room. When the unit is thermo-on, the load at the thermo-off time of the indoor unit is estimated based on the temperature difference between the suction temperature and the blow-out temperature of the operating indoor unit at the thermo-off time, and the wind speed of the blown air. , By multiplying the load factor of the entire system at the time of the thermo-on of the stopped indoor unit by the capacity of the indoor unit to estimate the load of the indoor unit at the time of thermo-on, subtotal values of these estimated loads and other operations Calculate the total value with the load of the indoor unit in, based on the calculated total load, change the capacity of the capacity variable compressor,
An operation control means for operating the outdoor unit for a predetermined time is provided.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1a and 1b denote outdoor units, and 3a and 3b denote indoor units. The outdoor unit 1a includes an accumulator 10a, a compressor 11a driven by a gas engine, and an oil separator 12a.
a, a four-way valve 13a, an outdoor heat exchanger 14a, and an outdoor electric expansion valve 15a. In addition, 1
7a denotes a fan of the outdoor heat exchanger 14a. The outdoor unit 1b is the same as the outdoor unit 1a, including the following configuration, and a description thereof will be omitted.

The indoor unit 3a includes an indoor heat exchanger 34a and an indoor electric expansion valve 35a (hereinafter referred to as an "indoor mechanical valve 35a"). Note that the indoor unit 3b is the same as the indoor unit 3a, including the following configuration, and a description thereof will be omitted. From this indoor unit 3a, 3b, an inter-unit pipe composed of a gas pipe 5 and a liquid pipe 7 extends, and outdoor units 1a, 1b are connected in parallel to this inter-unit pipe.

The oil separator 12a includes a compressor 11a
To separate the lubricating oil in the refrigerant discharged from the
The lubricating oil separated here is always returned to the compressor 11a through the oil return pipe 21a and the forced oil return pipe 22a. A capillary tube 24a is always provided in the oil return pipe 21a, and a flow path resistance is applied to oil returned to the compressor 11a by the capillary tube 24a. This constant oil return pipe 21a is connected in the middle of the oil separator 12a, and as long as the oil level of the oil in the oil separator 12a is higher than the position where the oil return pipe 21a is connected, the oil is constantly supplied to the compressor 11a through the constant oil return pipe 21a. It is returned to the suction pipe. On-off valves 23a and 25a are provided in the forced oil return pipe 22a.

The forced oil return pipe 22a is connected to the bottom of the oil separator 12a, and is provided with on-off valves 23a and 25a.
By opening a, the oil in the oil separator 12a is forcibly returned to the suction pipe of the compressor 11a.

The forced oil return pipes 22a and 22b of the outdoor units 1a and 1b are connected by a balance pipe 51. The balance pipe 51 is connected between the oil separator 12a and the check valve 18a through a third auxiliary pipe 53a, and the third auxiliary pipe 53a is provided with a third on-off valve 55a.

The third on-off valve 55a opens, and the four-way valve 13a
Is switched to the illustrated position, the balance pipe 51 communicates with the outdoor heat exchanger 14a.

In the air conditioner having the above configuration, in the present embodiment, the compressors 11a and 11b are driven by gas engines 100a and 100b, respectively. This compressor 11
The shafts 101a and 101b are led out from the main bodies of the motors a and 11b. Pulleys (not shown) are connected to the shafts 101a and 101b, and the output shafts of the gas engines 100a and 100b are connected via pulley V belts 102a and 102b. Have been.

In the above configuration, during the cooling operation, the refrigerant from the compressors 11a and 11b receives the oil separators 12a and 12b and the four-way valve 13 as indicated by solid arrows in FIG.
a, 13b, the outdoor heat exchangers 14a, 14b, and the outdoor electric expansion valves 15a, 15b, flow out to the liquid pipe 7, enter the indoor units 3a, 3b, and enter the indoor electric expansion valve 3.
5a, 35b, the indoor heat exchangers 34a, 34b flow in that order, flow out to the gas pipe 5, and further pass through the four-way valves 13a, 13b, the accumulators 10a, 10b, and the compressors 11a, 1b.
1b.

During the heating operation, the compressors 11a, 1
As shown by a dotted arrow in FIG. 1, the refrigerant from 1b flows through the oil separators 12a and 12b and the four-way valves 13a and 13b into the gas pipe 5, and flows into the indoor units 3a and 3a.
3b, flows in the order of the indoor heat exchangers 34a and 34b, the indoor electric expansion valves 35a and 35b, and flows out to the liquid pipe 7, and further, the outdoor electric expansion valves 15a and 15b and the outdoor heat exchanger 1
It is returned to the compressors 11a and 11b via 4a and 14b, four-way valves 13a and 13b, and accumulators 10a and 10b.

In this embodiment, one of the operating indoor units is stopped (hereinafter, referred to as thermo-off), or any of the stopped indoor units is started operating (hereinafter, thermo-off). -When it is turned on, it is characterized by the control of varying the compressor rotation speed of the outdoor unit.

When the indoor unit under operation is thermo-off, first, the suction temperature Tin and the blow-out temperature Tou of the indoor unit at the time of thermo-off according to the following equation (1).
Based on the temperature difference of t and the wind speed K of the blown air, the estimated load A of the indoor unit at the time of thermo-off is calculated.

[0021]

(Equation 1)

Then, a total value of the estimated load A and the loads of the other operating indoor units is calculated, and the capacity (speed) of the variable capacity compressor 11 is calculated based on the calculated total load. Is changed for a predetermined time (for example, 2 minutes).

When the stopped indoor unit is thermo-on, the load factor Usys of the whole system at the time of the thermo-on of the indoor unit is multiplied by the capacity QI of the indoor unit according to the following equation (2). The estimated load B at the time of turning on is calculated.

[0024]

(Equation 2)

Then, a total value of the estimated load B and the loads of the other operating indoor units is calculated, and based on the calculated total load, the capacity (the number of revolutions) of the variable capacity compressor 11 is determined. Is changed, for example, for 2 minutes.

Since the indoor unit thermo-on and thermo-off are repeated, if the estimated load of the indoor unit at the time of thermo-off is Aj and the estimated load of the indoor unit at the time of thermo-on is Bj, the outdoor unit The instruction rotation speed N of the unit is calculated and determined according to the following Equation 3.

[0027]

(Equation 3)

The above control is controlled by a centralized control device 16 which controls the outdoor units 1a and 1b in a comprehensive manner. During execution of this control, the increase or decrease control of the number of operating outdoor units is not performed.

It should be noted that the designated rotation speed N and the actual rotation speed are
For example, when the rotation speed is less than 100 rpm, or when the designated rotation speed N is equal to or higher than the actual rotation speed, the compressor 1
No control to change one ability is performed.

When the indoor unit stops operating (thermo-off) or starts operating (thermo-on), if the capacity of the indoor unit is suddenly removed from the control target, the other indoor unit will stop operating. This affects the indoor unit during operation, and the outlet temperature of the indoor unit greatly changes, which may cause discomfort to the user.

In the present embodiment, the control according to the above equation (3) is executed, for example, for 2 minutes, so that the blow-out temperature in the operating indoor unit suddenly drops significantly.
Since it does not increase, the blowout temperature of the indoor unit during operation does not significantly change, and discomfort can be reduced.

Further, since the followability to the load is improved, the high pressure in the refrigerant circuit does not rise abnormally, and the high pressure cut is prevented.

In the above control, after two minutes have elapsed, the control is shifted to the normal control, and the compressor rotation speed of the outdoor unit,
Alternatively, the number of operating units is controlled.

Although the present invention has been described based on one embodiment, the present invention is not limited to this.

[0035]

According to the present invention, since the blow-out temperature of the indoor unit during operation does not greatly decrease or increase, the blow-out temperature of the indoor unit during operation does not greatly change. Pleasure can be reduced.

Further, since the followability to the load is improved, the high pressure in the refrigerant circuit does not rise abnormally, and the high pressure cut is prevented.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an example of an air conditioner according to the present invention.

[Explanation of symbols]

 1, 1a, 1b Outdoor unit 3a, 3b Indoor unit 16 Centralized control device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Kazuo Kumehara 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Akira Shindo 2-5-2 Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. (72) Yoshihiro Nakamura 2-5-5 Keihanhondori 2-chome, Moriguchi City, Osaka Prefecture (72) Ryota Hirata 2 Keihanhondori, Moriguchi City, Osaka Prefecture 5-5-5 Sanyo Electric Co., Ltd. (72) Inventor Junji Matsue 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka 2-5 Sanyo Electric Co., Ltd. (72) Inventor Yoshito Tajima Moriguchi-shi, Osaka 2-5-5 Keihanhondori Sanyo Electric Co., Ltd. F-term (reference) 3L060 AA05 CC02 CC09 DD02 EE02 3L092 GA09 JA01 KA13 LA07

Claims (3)

[Claims] In an air conditioner in which a plurality of indoor units are connected to an outdoor unit equipped with a variable capacity compressor, when an operating indoor unit is thermo-offed, the temperature of the indoor unit at the time of thermo-off is reduced. Estimate the load of the indoor unit at the time of thermo-off based on the temperature difference between the suction temperature and the blow-out temperature, and the wind speed of the blown air, and calculate the total value of this estimated load and the load of other indoor units during operation An air conditioner comprising: an operation control unit that changes the capacity of the variable capacity compressor based on the calculated total load and operates the outdoor unit for a predetermined time. 2. An air conditioner in which a plurality of indoor units are connected to an outdoor unit equipped with a variable-capacity compressor, wherein when a stopped indoor unit is thermo-on, when the indoor unit is thermo-on, The load factor of the indoor unit at the time of thermo-on is estimated by multiplying the load factor of the indoor unit by the load factor of the entire system, and the total value of the estimated load and the load of the other indoor unit during operation is calculated. An air conditioner, comprising: operation control means for changing the capacity of the variable capacity compressor based on the calculated total load and operating the outdoor unit for a predetermined time. 3. In an air conditioner in which a plurality of indoor units are connected to an outdoor unit equipped with a variable capacity compressor, an operating indoor unit is thermo-off, and a stopped indoor unit is thermo-on. In the case, the temperature difference between the suction temperature and the outlet temperature at the time of thermo-off of the indoor unit during operation,
And the load at the time of thermo-off of the indoor unit is estimated based on the wind speed of the blown air, and the load factor of the entire system at the time of thermo-on of the indoor unit being stopped is multiplied by the capacity of the indoor unit to obtain the indoor unit. Estimate the load at the time of thermo-on of the unit, calculate the total value of the subtotal value of these estimated loads and the load of the other indoor units during operation, and based on the calculated total load, An air conditioner, comprising: operation control means for operating the outdoor unit for a predetermined time by changing the capacity of the air conditioner.