JP2002195676A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner, in which unwanted temperature drop of supply air is prevented, to enhance amenity and reliability of the apparatus. SOLUTION: When a heating cycle is established and an air supply mode is established in any of indoor equipment B1, B2 and B3, a refrigerant is passed through a capillary tubes (15, 25 and 35) of indoor equipment, in which the air-supply mode is established. Second indoor heat exchangers (16, 26 and 36) and first indoor heat exchangers (13, 23, and 33) are made to function respectively as condensers and evaporators. Then, the valve travel for one of flow regulating valves (11, 21 and 31) corresponding to indoor equipment, in which air-supply mode is established, is controlled to regulate temperature of supply air of the indoor equipment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a multi-type air conditioner having an outdoor unit and a plurality of indoor units.

[0002]

2. Description of the Related Art In an outdoor unit having a compressor and an outdoor heat exchanger, and a multi-type air conditioner having a plurality of indoor units each having an indoor heat exchanger, an air conditioning load of a room where each indoor unit is installed is known. Is detected, and the operating frequency of the compressor is controlled according to the sum of these air conditioning loads. As a result, an optimal cooling capacity or heating capacity corresponding to the total air conditioning load can be obtained.

[0003] An example of such a multi-type air conditioner is disclosed in Japanese Patent No. 2999818. In this example, the indoor heat exchanger of each indoor unit is divided into two, and a parallel circuit of an on-off valve and a decompressor is provided between the interconnections of the two indoor heat exchangers. In an indoor unit in which a so-called ventilation mode such as a single operation of a purifier is set, one indoor heat exchanger functions as a condenser and the other indoor heat exchanger functions as an evaporator by closing the on-off valve, and is equal to the indoor temperature. I try to blow out air at the level temperature.

[0004]

When the two indoor heat exchangers function as a condenser and an evaporator as described above, the temperature of the indoor heat exchanger functioning as an evaporator depends on the temperature of the outdoor heat exchanger. Receive. For example, when the outside air temperature is low and the temperature of the outdoor heat exchanger is low, the temperature of the indoor heat exchanger that functions as an evaporator also becomes low, and the temperature of the air blown into the room drops, causing discomfort to people in the room. Sometimes.

[0005] The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a highly reliable air conditioner capable of avoiding unnecessary lowering of the blown air temperature and improving comfort.

[0006]

An air conditioner according to a first aspect of the present invention is connected to an outdoor unit having a compressor, a four-way valve, and an outdoor heat exchanger via a decompression unit and a bypass unit. A plurality of indoor units having the first indoor heat exchanger and the second indoor heat exchanger, the compressor, the four-way valve, the outdoor heat exchanger, each first indoor heat exchanger, each parallel circuit, and each second indoor unit. A heat pump refrigeration cycle configured by pipe connection of a heat exchanger and capable of selectively setting a cooling cycle and a heating cycle with a four-way valve, and a plurality of heat pump refrigeration cycles that regulate the amount of refrigerant flowing to each indoor unit in the heat pump refrigeration cycle. When the airflow mode is set in any of the indoor units when the heating cycle is set, and when the heating cycle is set, the refrigerant is passed through the pressure reducing means of the indoor unit in which the airflow mode is set, and the second air conditioner of the indoor unit is set. First control means for causing the indoor heat exchanger to function as a condenser and the first indoor heat exchanger to function as an evaporator; and opening of a flow control valve corresponding to the indoor unit in which the blow mode is set among the respective flow control valves. Second control means for controlling the temperature and adjusting the temperature of the blown air of the indoor unit.

An air conditioner according to a second aspect of the present invention is the air conditioner according to the first aspect, further comprising an indoor temperature sensor for detecting a temperature of a room in which each indoor unit is installed.
Then, the second control means adjusts the opening degree of the flow control valve so that the detected temperature of the indoor temperature sensor in the indoor unit in which the blow mode is set falls within a predetermined range based on the detected temperature at the start of the blow mode. Control.

An air conditioner according to a third aspect of the present invention is the air conditioner according to the first aspect, further comprising an indoor temperature sensor for detecting a temperature of a room in which each indoor unit is installed, and each first indoor heat exchanger. A first heat exchanger temperature sensor for detecting the temperature of
A second heat exchanger temperature sensor for detecting the temperature of each second indoor heat exchanger. Then, the second control means detects the detected temperature Ta of the indoor temperature sensor and the detected temperature Tc of the first heat exchanger temperature sensor in the indoor unit in which the blow mode is set.
1. An operation [(Tc2−Ta) / (Ta−Tc1)] based on the detected temperature Tc2 of the second heat exchanger temperature sensor is executed, and the opening of the flow control valve is controlled so that the operation result becomes a constant value. I do.

The air conditioner according to a fourth aspect of the present invention is the air conditioner according to the first aspect of the present invention, further comprising the step of: supplying refrigerant to the bypass unit in the stopped indoor unit when both indoor units are in operation and stopped. There is provided a third control means for passing.

According to a fifth aspect of the present invention, in the air conditioner according to the first aspect, when a dehumidification mode is set in any of the indoor units, a cooling cycle is set and the dehumidification mode is set. Control means is provided for allowing the first indoor heat exchanger of the indoor unit to function as an evaporator and for the second indoor heat exchanger to function as a condenser by passing the refrigerant through the set indoor unit decompression means.

[0011]

[1] Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a plurality of indoor units B1, B2, and B3 are connected to the outdoor unit A by pipes, and a multi-type refrigeration cycle is configured. The outdoor unit A has a compressor 1 and an outdoor heat exchanger 3. The indoor unit B1 has a first indoor heat exchanger 13 and a second indoor heat exchanger 16, and these indoor heat exchangers 13, 16
Decompression means, such as the capillary tube 1
5 is provided in parallel with the on-off valve 14 serving as a bypass means. The indoor unit B2 includes a plurality of indoor heat exchangers 23,
26, and a parallel circuit of a pressure reducing means such as a capillary tube 25 and an on-off valve 24 as a bypass means is provided between the interconnections of the indoor heat exchangers 23 and 26. The indoor unit B3 has a plurality of indoor heat exchangers 33 and 36, and a parallel circuit of a pressure reducing means such as a capillary tube 35 and an on-off valve 34 as a bypass means between the indoor heat exchangers 33 and 36. Is provided. As the on-off valves 14, 24, 34, solenoid valves or temperature-driven valves using a shape memory alloy, which allow refrigerant to flow in both directions, are employed.

The outdoor heat exchanger 3 is connected to a discharge port of the compressor 1 via a four-way valve 2, and a packed valve 12 is connected to the outdoor heat exchanger 3 via a flow control valve, for example, an electronic expansion valve 11. Have been. The indoor heat exchanger 13 of the indoor unit B1 is connected to the packed valve 12, and the indoor unit B
The packed valve 18 is connected to one indoor heat exchanger 16. The suction port of the compressor 1 is connected to the packed valve 18 via the four-way valve 2.

A packed valve 22 is connected to the outdoor heat exchanger 3 via a flow control valve, for example, an electronic expansion valve 21. An indoor heat exchanger 23 of the indoor unit B2 is connected to the packed valve 22, and a packed valve 28 is connected to the indoor heat exchanger 26 of the indoor unit B2. And
The suction port of the compressor 1 is connected to the packed valve 28 via the four-way valve 2.

Further, a packed valve 32 is connected to the outdoor heat exchanger 3 via a flow control valve, for example, an electronic expansion valve 31. An indoor heat exchanger 33 of the indoor unit B3 is connected to the packed valve 32, and a packed valve 38 is connected to the indoor heat exchanger 36 of the indoor unit B3. The suction port of the compressor 1 is connected to the packed valve 38 via the four-way valve 2.

By such a pipe connection, a heat pump type refrigeration cycle capable of selectively setting a cooling cycle (dehumidification cycle) and a heating cycle by the four-way valve 2 is constituted.

The electronic expansion valves 11, 21, 31 are pulse motor valves (PMV) whose opening continuously changes in accordance with the number of supplied drive pulses, and are indoor units B1, B2,
It has a function of adjusting the amount of refrigerant flowing to B3 by changing the opening degree.

An outdoor fan 4 for introducing outside air is provided near the outdoor heat exchanger 3. An indoor fan 17 for circulating the indoor unit is provided near the indoor heat exchangers 13 and 16, and an indoor temperature sensor 40 for detecting the temperature of the room where the indoor unit B1 is installed in the suction air passage of the indoor fan 17 is provided. Is provided. An indoor fan 27 for circulating the indoor unit is provided near the indoor heat exchangers 23 and 26, and an indoor temperature sensor 50 for detecting the temperature of the room where the indoor unit B2 is installed in the suction air passage of the indoor fan 27 is provided. Is provided. An indoor fan 3 for circulating indoor units is provided near the indoor heat exchangers 33 and 36.
7 is provided, and an indoor temperature sensor 60 for detecting the temperature of the room where the indoor unit B3 is installed is provided in a suction air passage of the indoor fan 37.

The indoor heat exchanger 13 has a heat exchanger temperature sensor 4
1 is attached, and the heat exchanger temperature sensor 42 is attached to the indoor heat exchanger 16. A heat exchanger temperature sensor 51 is attached to the indoor heat exchanger 23, and a heat exchanger temperature sensor 52 is attached to the indoor heat exchanger 26. A heat exchanger temperature sensor 61 is attached to the indoor heat exchanger 33, and a heat exchanger temperature sensor 62 is attached to the indoor heat exchanger 36.

A temperature sensor 31 is mounted on the dehumidifying heat exchanger 13 sucked by the indoor fan 17, and a temperature sensor 32 is mounted on the indoor heat exchanger 14. A temperature sensor 33 is attached to a pipe between the packed valve 15 and the four-way valve 2.

A temperature sensor 41 is mounted on the dehumidifying heat exchanger 23, and a temperature sensor 42 is mounted on the indoor heat exchanger 24. A temperature sensor 43 is attached to a pipe between the packed valve 25 and the four-way valve 2.

FIG. 2 shows the control circuit.

The outdoor control unit 70 of the outdoor unit A is connected to the commercial AC power supply 71. The outdoor control unit 70 includes the electric expansion valves 11, 21, 31, the four-way valve 2, the outdoor fan motor 4
M and an inverter circuit 72 are connected. The inverter circuit 72 rectifies the voltage of the power supply 71, converts the rectified voltage into a voltage (and level) having a frequency (and level) according to a command from the outdoor control unit 70, and outputs the voltage. This output is the driving power of the compressor motor 1M.

Each of the indoor units B1, B2 and B3 has an indoor control unit 80. These indoor control units 80 include indoor temperature sensors 40, 50, 60 and indoor fan motors 17M, 2
7M, 37M and the light receiving section 81 are connected respectively. The light receiving unit 81 receives infrared light emitted from a remote control type operation device (hereinafter, simply referred to as a remote control) 82.

The indoor control unit 80 and the outdoor control unit 70 are connected by a power supply line ACL and a data transmission serial signal line SL, respectively.

Each indoor control unit 80 has the following means (1) to (3) as main functions.

(1) Means for notifying the outdoor unit A of operating conditions (including the set indoor temperature Ts) by operating the remote controller 62 by a serial signal synchronized with the power supply voltage.

(2) The indoor temperature sensor 40 (and 50,
Means for detecting the difference between the detected temperature Ta of 60) and the set indoor temperature Ts set by the remote controller 82 as an air conditioning load, and informing the outdoor unit A of a required capacity corresponding to the air conditioning load.

(3) Temperature sensors 41 and 42 (and 5)
1, 52, 61, 62) means to notify the outdoor unit A of the detected temperatures T1, T2.

The outdoor controller 70 has the following means (11) to (16) as main functions.

(11) When the indoor units B1, B2, B3 issue a cooling mode operation request, the on-off valves 14, 24,
34, the refrigerant discharged from the compressor 1 is supplied to the four-way valve 2, the outdoor heat exchanger 3, the electronic expansion valves 11, 21, 31, the first indoor heat exchangers 13, 23, 33, and the on-off valves 14, 24. ,
34, a cooling cycle for returning to the compressor 1 through the second indoor heat exchangers 16, 26, 36 and the four-way valve 2, and an electronic expansion valve according to the required capacity from the indoor units B1, B2, B3. Means for controlling the opening degrees of 11, 21, 31 respectively.

(12) Means for setting the cooling cycle and closing the on-off valves 14, 24, 34 when an operation request in the dehumidification mode is issued from the indoor units B1, B2, B3.

(13) When the indoor units B1, B2, and B3 issue a heating mode operation request, the indoor units B1, B2
Opening the on-off valves 14, 24 and 34 of the compressors 2 and B3, the compressor 1
Refrigerant discharged from the four-way valve 2, the second indoor heat exchanger 1
6, 26, 36, on-off valves 14, 24, 34, first indoor heat exchangers 13, 23, 33, electronic expansion valves 11, 21, 3
1, the outdoor heat exchanger 3, and the compressor 1 through the four-way valve 2.
And the indoor unit B1,
The electronic expansion valves 11, 2 according to the required capacity from B2, B3
Means for controlling the opening degree of each of the first and the third.

(14) When a heating cycle is set and a blow mode (blowing operation or air purifier single operation) is set in any of the indoor units B1, B2 and B3,
Open / close valves (11, 21, 21) of the indoor units in which the blow mode is set
31) is closed and the second indoor heat exchanger (16, 26, 36)
And a first indoor heat exchanger (13, 23, 33), a refrigerant flow path passing through a capillary tube (15, 25, 35) is formed, and a second indoor heat exchange of the indoor unit in which the blow mode is set The function of the condenser (16, 26, 36) as a condenser
First control means for causing the indoor heat exchangers (13, 23, 33) to function as evaporators.

(15) Among the electronic expansion valves 11, 21 and 31, the opening degree of the electronic expansion valve corresponding to the indoor unit in which the air blowing mode is set is controlled to adjust the blow-out air temperature of the indoor unit. Control means. Specifically, the detected temperature Ta of the indoor temperature sensors (40, 50, 60) in the indoor units (B1, B2, B3) in which the blow mode is set is within a predetermined range based on the detected temperature at the start of the blow mode. The opening degree of the electronic expansion valves (11, 21, 31) is controlled so as to fall within the range.

(16) Third control means for opening the on-off valves (11, 21, 31) of the stopped indoor units when the indoor units B1, B2, B3 are both running and stopped.

Next, the operation of the above configuration will be described with reference to the flowchart of FIG.

A heating cycle is formed, and the indoor units B1, B
In the case where the heating operation is performed in B2 and B3, for example, when the air blowing mode (the air blowing operation or the air purifier alone operation) is set in the indoor unit B2, the on-off valve 21 of the indoor unit B2 is closed. When the on-off valve 21 is closed, the second indoor heat exchanger 2
6 passes through the capillary tube 25 and flows into the first indoor heat exchanger 23, the second indoor heat exchanger 26 functions as a condenser, and the first indoor heat exchanger 23 functions as an evaporator. . Therefore, the air sucked by the indoor fan 27 is adjusted to a temperature close to the indoor temperature and is blown into the room.

FIG. 3 shows the enthalpy pressure line at this time. The refrigerant in the first indoor heat exchanger 23 evaporates at an intermediate pressure between the refrigerant pressure in the second indoor heat exchanger 26 and the refrigerant pressure in the outdoor heat exchanger 3. This evaporation temperature Tc1 changes according to the opening degree of the electronic expansion valve 21, as shown in FIG. Note that the evaporation temperature Te of the refrigerant in the outdoor heat exchanger 3 changes according to the outside air temperature.

The temperature of the air blown from the indoor unit B2 in the blowing mode depends on the heating capacity of the second indoor heat exchanger 26 [= K
1 · (Tc2−Ta)] and the cooling capacity of the first indoor heat exchanger 23 [= K2 · (Ta−Tc1)]. K1 is the heat exchange rate of the heating side heat exchanger, and K2 is the heat exchange rate of the cooling side heat exchanger.

The resident of the room where the indoor unit B2 in the blowing mode is installed desires the room temperature when the blowing mode is set. Therefore, the detected temperature Ta of the indoor temperature sensor 50 when the air blowing mode is set is stored as Ta1, and the detected temperature Ta of the indoor temperature sensor 50 falls within a predetermined range based on the stored value Ta1, in other words, the indoor temperature. The opening of the electronic expansion valve 21 is controlled so that the detected temperature Ta of the sensor 50 does not deviate from a predetermined range based on the stored value Ta1.

Therefore, even when the outside air temperature is low and the temperature of the outdoor heat exchanger 3 is low, it is possible to avoid an unnecessary decrease in the temperature of the blown air, so that the occupants do not feel uncomfortable. Stated another way, it is possible to maintain the indoor temperature environment at an optimum state desired by the resident, thereby improving comfort. As a result, the reliability as an air conditioner is greatly improved.

When the indoor units B1, B2, and B3 are performing the heating operation, for example, when the operation of the indoor unit B1 is stopped, the on-off valve 11 of the indoor unit B1 is opened, and the indoor unit B1 is opened. The electronic expansion valve 11 corresponding to the machine B1 is maintained at a predetermined opening. Thereby, the refrigerant also flows through the indoor heat exchangers 13 and 16 in the stopped indoor unit B1, and the accumulation of the refrigerant in the indoor heat exchangers 13 and 16 can be eliminated.

During the heating operation of the indoor units B1, B2, and B3, when the operation of the indoor unit B1 as an evaporator is stopped, for example, the on-off valve 11 of the indoor unit B1 is opened and the indoor unit B1 is opened. Is maintained at a predetermined opening degree. Thereby, the refrigerant also flows through the indoor heat exchangers 13 and 16 in the stopped indoor unit B1, and the accumulation of the refrigerant in the indoor heat exchangers 13 and 16 can be eliminated.

When the operation request of the dehumidification mode is issued from, for example, the indoor unit B1 among the indoor units B1, B2, and B3, the cooling cycle is formed, and the opening / closing valve 11 of the indoor unit B1 is closed. A refrigerant flow path passing through the capillary tube 15 is formed between the first indoor heat exchanger 13 and the second indoor heat exchanger 16, and the first indoor heat exchanger 13 functions as an evaporator, and the second indoor heat exchange The vessel 16 functions as a condenser. The air taken in from the room is cooled and dehumidified in the first indoor heat exchanger 13, warmed to a state close to the room temperature in the second indoor heat exchanger 16, and blown into the room.

[2] A second embodiment will be described.

In the first embodiment, as a specific example of the functional means (14) of the outdoor control unit 70, the indoor temperature sensors (40, 50, 60) in the indoor units (B1, B2, B3) in which the air blow mode is set. ), The opening degree of the electronic expansion valves (11, 21, 31) is controlled so that the detected temperature Ta falls within a predetermined range based on the detected temperature at the start of the blow mode.
In the embodiment, as a specific example of the functional unit (14) of the outdoor control unit 70, the indoor unit (B1,
B2, B3) indoor temperature sensors (40, 50, 6)
0), the first heat exchanger temperature sensor (13,
(Tc2−Ta) / (Ta−Tc1)] based on the detected temperature Tc1 of the second heat exchanger temperature sensor (16, 26, 36) and the detected temperature Tc1 of the second heat exchanger temperature sensor (23, 33). The electronic expansion valves (11,
1, 31) is controlled.

This is because the first indoor heat exchangers 13, 23, 3
3 and the second heat exchanger temperature sensors 16, 2
The heat exchange rates of the first and second indoor heat exchangers 6 and 36 are controlled by controlling the degree of opening of the electronic expansion valves 11, 21 and 31 so that the above calculation result becomes a constant value. Vessel 1
By adjusting the temperatures Tc1 of 3, 23, and 33, a comfortable indoor temperature environment can be created.

The other structure, operation and effect are the same as those of the first embodiment.

In each of the above embodiments, the capillary tube 15 and the on-off valve 14 are used as the pressure reducing means and the bypass means. However, the electronic expansion valve is used as the pressure reducing means, and the electronic expansion valve is fully opened. It may be configured to be used as bypass means. In addition, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention.

[0050]

As described above, according to the present invention, it is possible to provide a highly reliable air conditioner that can avoid unnecessary lowering of the blown air temperature and improve comfort.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a refrigeration cycle of each embodiment.

FIG. 2 is a block diagram of a control circuit of each embodiment.

FIG. 3 is a diagram showing an enthalpy pressure line in each embodiment.

FIG. 4 is a diagram showing a relationship between an evaporation temperature and an opening degree of an electronic expansion valve in the embodiment.

[Explanation of symbols]

A: outdoor unit, B1, B2, B3: indoor unit, 1: compressor,
2 ... four-way valve, 3 ... outdoor heat exchanger, 11, 21, 31 ... electronic expansion valve (flow control valve), 13, 23, 33 ... first indoor heat exchanger, 14, 24, 34 ... open / close valve (bypass) Means, 15, 25, 35 ... capillary tube (decompression means), 16, 26, 36 ... second indoor heat exchanger, 70 ... outdoor control unit, 80 ... indoor control unit

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) F25B 29/00 321 F25B 29/00 321

Claims (5)

[Claims] 1. An outdoor unit having a compressor, a four-way valve, and an outdoor heat exchanger, and a first indoor heat exchanger and a second indoor heat exchanger interconnected via a pressure reducing means and a bypass means thereof. A plurality of indoor units, configured by a pipe connection of the compressor, the four-way valve, the outdoor heat exchanger, the first indoor heat exchangers, the parallel circuits, and the second indoor heat exchangers, A heat pump refrigeration cycle in which a cooling cycle and a heating cycle can be selectively set by a four-way valve; a plurality of flow control valves for adjusting an amount of refrigerant flowing to each indoor unit in the heat pump refrigeration cycle; and the heating cycle. Is set, when the blow mode is set in any of the indoor units, the refrigerant is passed through the pressure reducing means of the indoor unit in which the blow mode is set, and the second indoor heat exchange of the indoor unit is performed. Control means for making the unit function as a condenser and functioning the first indoor heat exchanger as an evaporator; and the opening degree of the flow control valve corresponding to the indoor unit in which the blow mode is set among the flow control valves And a second control means for controlling the temperature of the air blown out of the indoor unit. 2. The air conditioner according to claim 1, further comprising: an indoor temperature sensor configured to detect a temperature of a room where each of the indoor units is installed, wherein the second control unit is configured to set the blowing mode. An air conditioner, wherein an opening degree of a flow control valve is controlled so that a detection temperature of the indoor temperature sensor in the indoor unit falls within a predetermined range based on a detection temperature at the time of starting a ventilation mode. 3. The air conditioner according to claim 1, wherein an indoor temperature sensor for detecting a temperature of a room where each of the indoor units is installed, and a first temperature for detecting a temperature of each of the first indoor heat exchangers. A heat exchanger temperature sensor, and a second heat exchanger temperature sensor for detecting the temperature of each of the second indoor heat exchangers, wherein the second control means is provided for the indoor unit in which the blowing mode is set. Calculation based on the detected temperature Ta of the indoor temperature sensor, the detected temperature Tc1 of the first heat exchanger temperature sensor, and the detected temperature Tc2 of the second heat exchanger temperature sensor [(Tc
2-Ta) / (Ta-Tc1)], and controls the opening of the flow control valve so that the calculation result becomes a constant value. 4. The air conditioner according to claim 1, further comprising: third control means for passing a refrigerant through a bypass means in the stopped indoor unit when both the indoor unit and the indoor unit are in operation and stopped. An air conditioner characterized by that: 5. The air conditioner according to claim 1, wherein when the dehumidification mode is set in any of the indoor units, the cooling cycle is set, and the pressure in the indoor unit set in the dehumidification mode is reduced. Means of the indoor unit
An air conditioner comprising: control means for causing the indoor heat exchanger to function as an evaporator and the second indoor heat exchanger to function as a condenser.