JP3108202B2 - Operation control method for air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control method for an air conditioner having a plurality of indoor units.

[0002]

2. Description of the Related Art As an air conditioner of this type, for example, an outdoor unit having a compressor and an outdoor heat exchanger and a plurality of units having an indoor heat exchanger disclosed in Japanese Patent Publication No. 3-50466 are disclosed. 2. Description of the Related Art A cooling / heating device having a configuration in which an indoor unit and an indoor unit are connected by a piping between units is well known.

[0003] In the above-mentioned conventional apparatus, the flow control of the refrigerant to each of a plurality of indoor units is controlled by a temperature sensor installed in the indoor heat exchanger so that the indoor heat exchanger temperature of each indoor unit becomes equal, for example, during heating. To explain by way of example, the electric valve of the indoor unit having a high heat exchanger temperature is controlled by reducing the opening, and the electric valve of the indoor unit having a low temperature is controlled by opening the opening.

[0004]

However, in the above-mentioned conventional apparatus, the piping length and the installation height of the indoor units are extremely different from each other, or the refrigerant pipe is clogged with foreign matter or crushed, so that the refrigerant may be damaged. If there is an indoor unit that is extremely difficult to flow, it tries to flow the refrigerant into the indoor unit where the refrigerant does not easily flow, so the other indoor units reduce the amount of refrigerant, so the air discharge temperature decreases, and the feeling of warm air disappears There is a problem called

[0005] Further, in an apparatus in which an indoor unit designed to have a low air blowing temperature and an indoor unit designed to be high are mixed, there is another problem that the blowing temperature of an indoor unit designed to have a high blowing temperature becomes low. , These solutions had been an issue.

[0006]

According to the present invention, as a specific means for solving the above-mentioned problems of the prior art, a compressor for refrigerant, a four-way valve, an outdoor heat exchanger, an outdoor expansion valve, an indoor electric valve,
In an air conditioner in which a cooling / heating circuit is formed by sequentially connecting an indoor heat exchanger, an accumulator, and the like, the temperature of the hot air blown out by the heat exchange or the temperature of the cold air blown by the heat exchange in the indoor heat exchanger. An operation control method in an air conditioner, which controls an opening degree of an indoor electric valve based on a difference from a set outlet temperature,

A plurality of indoor units each having an indoor heat exchanger are provided, and a difference between a blown air temperature heated by the heat exchange in each indoor heat exchanger and each set blown air temperature is obtained, and the temperature difference is calculated. When the minimum value of the indoor electric valve corresponding to the indoor heat exchanger having a positive temperature difference is increased, the opening degree of the indoor electric valve corresponding to the indoor heat exchanger having a negative temperature difference is increased. An operation control method in the air conditioner described above, which reduces the opening,

A plurality of indoor units each having an indoor heat exchanger are provided, and a difference between a blow-out temperature of the cool air cooled by the heat exchange in each indoor heat exchanger and each set blow-out temperature is obtained. When the maximum value of the indoor heat exchanger corresponding to the indoor heat exchanger having a negative temperature difference is increased, the opening degree of the indoor motor-operated valve corresponding to the indoor heat exchanger having a positive temperature difference is increased. An object of the present invention is to solve the above-described problem of the related art by providing an operation control method for an air conditioner that reduces an opening degree.

[0009]

[Function] Heating operation when a plurality of indoor heat exchangers are provided;
The difference between the blow-out temperature of warm air heated by heat exchange in each indoor heat exchanger and each set blow-out temperature is obtained, and when the minimum value of this temperature difference is negative, there is an indoor unit having insufficient heating capacity. Therefore, the opening degree of the indoor motor-operated valve of the indoor heat exchanger in which the heating capacity is insufficient due to the negative temperature difference is increased so that the refrigerant flow rate is increased, and the heat exchange amount is increased. The indoor motor-operated valve of the indoor heat exchanger in which sufficient heating is performed is reduced in the opening degree and the refrigerant flow rate is reduced, so that the amount of heat exchange is reduced.

[0010] Cooling operation when a plurality of indoor heat exchangers are provided; the difference between the blow-out temperature of cold air cooled by heat exchange in each indoor heat exchanger and each set blow-out temperature is determined, and the maximum value of this temperature difference Is positive, there is an indoor unit with insufficient cooling capacity, so the temperature difference is positive and the opening degree of the indoor motor-operated valve of the indoor heat exchanger with insufficient cooling capacity increases the refrigerant flow rate. The indoor motor-operated valve of the indoor heat exchanger, which opens to increase the amount of heat exchange and the temperature difference becomes negative and sufficient cooling is performed, reduces the degree of opening and reduces the flow rate of the refrigerant. Decrease.

[0011]

FIG. 1 shows an outdoor unit U0 and an indoor unit U.
1 shows an example of an air conditioner system in which U2 is connected in parallel. In the figure, reference numeral 1 denotes a compressor driven by a gasoline engine, a gas engine, an electric motor, or the like;
A four-way valve for heating switching, 3 is an indoor heat exchanger, 4 is an indoor electric valve (hereinafter, referred to as an electric valve), which acts as an expander during cooling and acts as a refrigerant distribution control valve of each indoor unit during heating. Is a receiver tank, 6 is an outdoor expansion valve, 7 is an outdoor heat exchanger, 8 is an accumulator, each of which is a conventionally well-known device, which is sequentially connected via a refrigerant pipe L and is shown by a solid line. A cooling circuit A and a heating circuit B indicated by a broken line are formed.

The indoor units U1 and U2 exchange the air existing in the room with a refrigerant such as Freon flowing through the indoor heat exchanger 3 and blow it into the room, in addition to the indoor heat exchanger 3 and the motor-operated valve 4, respectively. It has an indoor fan 12, a temperature sensor 9 for measuring the temperature of air when exchanging heat with the indoor heat exchanger 3 and blowing out the room, and a temperature sensor 10 for measuring the temperature of air taken in from the room. Are connected so as to transmit measurement data to the controller 11 of the outdoor unit U0 and operate based on a control signal output from the controller.

The indoor units U1 and U2 include:
Each of the remote controllers 13 is electrically connected, and the remote controllers are provided with a switch for starting / stopping the system, a switch for setting a room temperature, a switch for setting a wind speed, and the like (none of them are shown).

The refrigerant compressed and discharged by the compressor 1 can be circulated in the two directions of the solid line and the broken line by switching the four-way valve 2 as described above.

When the heating circuit B shown by the dashed line is formed, the refrigerant which has been compressed by the compressor 1 and has become high temperature and high pressure flows into the indoor units U1 and U2 via the four-way valve 2, and In the indoor heat exchanger 3, the indoor fan 1
2 exchanges heat with the room air to be blown and heats it, and the refrigerant itself cools down and condenses. The indoor unit U
The distribution control of the refrigerant to each of 1 and U2 is performed by adjusting the opening of the electric valve 4 using a step motor or the like so as to correspond to each load.

The liquefied refrigerant is adiabatically expanded by the outdoor expansion valve 6 to become a low-temperature and low-pressure gaseous substance and passes through the outdoor heat exchanger 7 to be blown by an outdoor fan (not shown). The air is warmed by the outside air having a high temperature and flows back to the compressor 1 via the four-way valve 2 and the accumulator 8.

On the other hand, when the four-way valve 2 is switched to form the cooling circuit A shown by the solid line, the refrigerant which has been compressed by the compressor 1 and has become high temperature and high pressure when passing through the outdoor heat exchanger 7 The motor-operated valve 4 that is cooled and condensed by the relatively low-temperature outside air blown by the outdoor fan (not shown) and passes through the receiver tank 5 to each of the indoor units U1 and U2, in this case, functions as an expansion valve. Adiabatic expansion due to the passage of the air, the gas becomes a low-temperature and low-pressure gas body, flows into the corresponding indoor heat exchanger 3, and the indoor fan 12 exchanges heat with the indoor air blown from the room to cool the indoor air. -Reflux to the compressor 1 via the accumulator 8.

The heating operation will be described as an example. The indoor units U1, U2, the remote controller 13 and the controller 11
The information on the type of indoor unit such as blow-out temperature, indoor temperature, cassette type embedded in the ceiling, ceiling type suspended from the ceiling, floor type installed on the floor, etc., set room temperature, set wind speed, and presence or absence of operation For example, the opening degree of the motor-operated valve 4 which is input and obtained by the calculation based on FIG.
-Send to each of U2.

When calculating the target outlet temperature Trgt-i (i is the number of the indoor unit) of each of the indoor units U1 and U2, its characteristics are taken into account depending on the type of the indoor unit Ui and the set wind speed.

For example, in the case of a cassette type to be embedded in the ceiling, it is necessary to increase the blowing speed of the hot air in order to prevent hot air from accumulating on the ceiling. The blowing temperature is required. On the other hand, when the wind speed is set to "weak wind", the blow-out temperature is set to a slightly lower temperature in order to prevent accumulation of hot air on the ceiling.

On the other hand, in the floor installation type in which warm air is blown from the floor, a high outlet temperature is not required because the distance between the outlet and the person is short, so a lower temperature is set.

In consideration of various conditions as described above, even if the difference between the set room temperature and the room temperature is the same as shown in FIG. 3, for example, different targets are set depending on the type of the indoor unit Ui and the air blowing conditions. Set the outlet temperature Trgt-i.

A specific example of operation control is described as follows.
Referring to the flowchart of FIG. 2 in which it is assumed that there are multiple units, in step S1, i = 1, that is, the first indoor unit U1 is selected, and in step S2, the set room temperature Tset-1 and the room temperature Troom-1 relating to this indoor unit U1. , The blowout temperature Tout-1, the set wind speed FM-1, and the indoor type TP-1.

In step S3, based on FIG.
The target outlet temperature Trgt-1 is calculated and calculated. In the next step 4, the temperature difference δout- between the outlet temperature Tout-1 and the target outlet temperature Trgt-1 is calculated.
1 (= Tout−1−Trgt−1) is calculated.

In step S5, a determination is made on i. In this case, since i = 1, the process proceeds to the side of i <n.
In step S5, the new i is set to i (= 1) + 1 = 2, and the process returns to step S2. Then, Step S2 to Step S
The control of 5 is repeated until i = n. That is, the temperature difference δout-i is calculated for all the indoor units U1, U2,... Un.

The indoor unit U having a positive temperature difference δout-i
i has excess heat, and the negative indoor unit Ui needs to distribute heat from other indoor units Ui because the heating capacity is low.

In step S7, steps S2 to S2
The minimum temperature difference δout-min is searched from the temperature difference δout-i obtained by the repetitive control of step S5.

In step S8, the minimum temperature difference δout-mi
The value of n is determined. If this value is negative and there is an indoor unit that needs to distribute heat from another indoor unit, the process proceeds to step S9. If the value of n is other than negative, the process proceeds to step S15.

In step S9, i = 1, that is, the first indoor unit U1 is selected, and the value of the temperature difference δout-1 in this indoor unit U1 is determined in step S10.
If this value is positive and there is excess heat, the operation proceeds to step S11, in which the opening of the electric valve 4 is slightly closed to reduce the amount of circulating refrigerant and increase the amount of circulating refrigerant in other indoor units. If the answer is negative, the process proceeds to step S12, in which the opening of the electric valve 4 is slightly opened to increase the amount of circulating refrigerant to increase the heating capacity. When the temperature difference δout-1 takes any other value, the opening of the motor-operated valve 4 is not changed.

In the following step S13, the aforementioned step S
5, and the control of steps S10 to S13 is repeated until i = n, and the indoor unit U1, U2,... The operation of slightly closing the motor-operated valve 4 for each unit Ui and slightly opening the motor-operated valve 4 for each indoor unit Ui having the negative temperature difference δout-i is performed.

In step S15, the process proceeds when the value of the minimum temperature difference δout-min is other than negative and there is no indoor unit that needs to distribute heat from another indoor unit.
i = 1, that is, the first indoor unit U1 is selected, the opening degree of the electric valve 4 corresponding to this indoor unit U1 is slightly closed in step S16, the refrigerant flow rate is somewhat reduced, and the heating capacity is slightly reduced. To step S17.

In step S17, the same i determination as in step S5 is performed, and all indoor units U1, U2,... Un are subjected to step S1 until i = n.
6. The control of steps S17 and S18 is repeated, and the opening of each motor-operated valve 4 is gradually closed.

The opening / closing operation of the motor-operated valve 4 is repeatedly executed at predetermined time intervals, for example, every 10 seconds, and the indoor units U1, U2,... Un are controlled. .

FIG. 4 shows an example of control during the cooling operation.
The basic control is the same as in the case of the heating operation shown in FIG.

During the cooling operation, the indoor unit Ui having a positive temperature difference δout-i between the blow-out temperature Tout-i and the target blow-out temperature Trgt-i has a cooling capacity insufficient and cools the heat from the other indoor unit Ui. Allocation is required and negative indoor unit U
i is an indoor unit capable of distributing cold heat to other indoor units Ui because cooling is sufficiently performed.

Therefore, in step P7, step P
The temperature difference δ for all the indoor units U1, U2,.
Out-i is searched for the maximum temperature difference δout-max.

In step P8, the maximum temperature difference δout-ma
The value of x is determined, and if this value is positive and there is an indoor unit that requires distribution of cold from other indoor units, the process proceeds to step P9 / step P10, where a value other than positive is taken and sufficient cooling is performed. If so, the process proceeds to Step P15.

In step P10, the value of the temperature difference δout-i is determined. If this value is negative and there is excess cooling, the process proceeds to step P11, in which the opening of the motor-operated valve 4 is slightly closed to change the cooling capacity. Is slightly lowered, and the flow rate of the refrigerant to other indoor units is increased. When the value is positive and the cooling capacity is insufficient, the process proceeds to step P12, in which the opening of the electric valve 4 is slightly opened to increase the refrigerant circulation amount and increase the cooling capacity. When the temperature difference δout-i takes any other value, the opening of the motor-operated valve 4 is not changed.

In step P16, when the value of the maximum temperature difference δout-max is other than positive and there is no indoor unit requiring distribution of cold from other indoor units, all the indoor units U1, U2, ..For Un
The degree of opening of each motor-operated valve 4 is gradually closed to slightly reduce the flow rate of the refrigerant and slightly reduce the cooling capacity.

The opening / closing operation of the motor-operated valve 4 during the cooling operation is repeatedly executed at predetermined time intervals, for example, every 10 seconds.
Since the indoor units U1, U2,... Un are controlled,
Room temperature control is accurate.

Since the present invention is not limited to the above embodiment, various modifications can be made without departing from the spirit of the present invention.

[0042]

As described above, according to the present invention, a refrigerant compressor is connected to a four-way valve, an outdoor heat exchanger, an outdoor expansion valve, an indoor electric valve, an indoor heat exchanger, an accumulator, and the like in this order. In an air conditioner in which a heating circuit is formed, an indoor electric valve is provided based on a difference between a blowout temperature of warm air or a cool air blown by heating and heat exchanged by an indoor heat exchanger and a set blowout temperature. An operation control method in an air conditioner, characterized by controlling an opening degree of an air conditioner,

A plurality of indoor heat exchangers are provided, and the difference between the blow-out temperature of warm air heated and heat-exchanged in each indoor heat exchanger and each set blow-out temperature is obtained, and the minimum value of this temperature difference is negative. When, the opening degree of the indoor electric valve corresponding to the indoor heat exchanger having a negative temperature difference is increased, and the opening degree of the indoor electric valve corresponding to the indoor heat exchanger having a positive temperature difference is reduced. Item 12. An operation control method in the air conditioner according to item 1,

A plurality of indoor heat exchangers are provided, and the difference between the blow-out temperature of the cool air cooled by the heat exchange in each indoor heat exchanger and each set blow-out temperature is obtained, and the maximum value of this temperature difference is positive. When, the opening degree of the indoor electric valve corresponding to the indoor heat exchanger having a positive temperature difference is increased, and the opening degree of the indoor electric valve corresponding to the indoor heat exchanger having a negative temperature difference is reduced. Item 1 is an operation control method for an air conditioner according to Item 1,

Even if one of a plurality of indoor units becomes clogged with a refrigerant system, the air conditioning capacity of another indoor unit is not impaired. Even when the pressure loss of the refrigerant is large, for example, because the air conditioner is extremely higher than the others, the air conditioning capacity of the other indoor units is not impaired.

[Brief description of the drawings]

FIG. 1 is an apparatus configuration diagram of an embodiment.

FIG. 2 is an explanatory diagram showing a control method during a heating operation.

FIG. 3 is an explanatory diagram showing a procedure for setting a target outlet temperature Trgt.

FIG. 4 is an explanatory diagram showing a control method during a cooling operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Indoor heat exchanger 4 Electric valve 5 Receiver tank 6 Outdoor expansion valve 7 Outdoor heat exchanger 8 Accumulator 9, 10 Temperature sensor 11 Controller 12 Indoor fan U0 Outdoor unit U1, U2 Indoor unit A Cooling circuit B Heating circuit L Refrigerant pipe

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F24F 11/02 102 F25B 13/00 F25B 13/00 104

Claims (3)

(57) [Claims] An air conditioner in which a cooling / heating circuit is formed by sequentially connecting a refrigerant compressor with a four-way valve, an outdoor heat exchanger, an outdoor expansion valve, an indoor electric valve, an indoor heat exchanger, an accumulator, and the like. Wherein the opening degree of the indoor motor-operated valve is controlled based on the difference between the set temperature and the temperature of the hot air blown or heated by the heat exchange by the indoor heat exchanger. Operation control method in an air conditioner. 2. A plurality of indoor units each having an indoor heat exchanger, and a difference between a blow-out temperature of warm air heated by exchanging heat in each indoor heat exchanger and each set blow-out temperature is obtained. When the minimum value of the temperature difference is negative, the opening degree of the indoor electric valve corresponding to the indoor heat exchanger having a negative temperature difference is increased, and the indoor electric valve corresponding to the indoor heat exchanger having a positive temperature difference is increased. The operation control method for an air conditioner according to claim 1, wherein the opening degree of the valve is reduced. 3. A plurality of indoor units each having an indoor heat exchanger, and a difference between a blow-out temperature of cold air cooled by heat exchange in each indoor heat exchanger and each set blow-out temperature is obtained. When the maximum value of the temperature difference is positive, the opening of the indoor electric valve corresponding to the indoor heat exchanger having the positive temperature difference is increased, and the indoor electric valve corresponding to the indoor heat exchanger having the negative temperature difference is increased. The operation control method for an air conditioner according to claim 1, wherein the opening degree of the valve is reduced.