JP2716559B2 - Cooling / heating mixed type multi-room air conditioner - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mixed cooling / heating multi-room air conditioner capable of simultaneously operating a cooling operation and a heating operation.

[Conventional technology]

FIG. 3 shows a configuration diagram of a conventional multi-room air-conditioning apparatus disclosed in, for example, Japanese Patent Application Laid-Open No. 1-167561. In the figure, (1) is an outdoor unit, and (2) is a compressor. ,
(3) is an outdoor heat exchanger, and (4) is an accumulator. (5a), (5b), and (5c) are three indoor units.
a) (6b) and (6c) are indoor heat exchangers, (7) is a refrigerant discharge pipe, and (8) is a refrigerant suction pipe. (9a) (9b): switching valve, (10): outdoor unit (1) and indoor unit (5a)
(11) is a high-pressure gas refrigerant pipe, (12) is a low-pressure gas refrigerant pipe, and (13) is a liquid refrigerant pipe. (14a) (14b) (14c) and (15a)
(15b)) 15c) is a switching valve of each indoor unit (5a) to (5c), (16a) (16b) (16c) is a refrigerant pressure reducer, (17) is a bypass pipe, (20) is a refrigerant pressure reducer, (22) indicates a fan of the outdoor heat exchanger (3).

Next, the operation will be described. Here, the case where the indoor units (5a) and (5b) are in the heating mode and the indoor unit (5c) is in the cooling mode will be described. First, the high-temperature and high-pressure gas refrigerant discharged from the compressor (2) is guided to the indoor units (5a) and (5b) through the high-pressure gas refrigerant pipe (11) and passes through the switching valves (14a) and (14b). Heat exchanger (6a) (6
In b), it is condensed and liquefied, and becomes high-temperature liquid refrigerant and flows into the liquid refrigerant pipe (13) from the refrigerant decompressors (16a) and (16b). , And is diverted to the indoor unit (5c) and the outdoor unit (1), gasified and vaporized by the heat exchangers (6c) and (3), respectively, and then passed through the switching valves (15c) and (9b). Flow into (12). Thus, a refrigerant circuit is formed in which the low-pressure gas refrigerant is sucked from the low-pressure gas refrigerant pipe (12) through the accumulator (4) again into the compressor (2).

The operation of various devices constituting the refrigerant circuit is controlled as follows by a control device (not shown) provided on the outdoor unit (1) side.

The number of rotations of the compressor (2) that determines the capacity (refrigerant circulation amount) of the compressor (2) is determined by each room thermo (not shown) provided in each room on the indoor units (5a) to (5c) side. Is controlled based on the cold / warm ON-OFF signal transmitted by

In addition, it is one factor that determines the capacity of the outdoor heat exchanger,
The rotation speed of a fan (22) serving as an outdoor blower is controlled based on a temperature difference between an outside air temperature detected by an outside air thermometer (not shown) provided in the outdoor unit (1) and a preset temperature. .

Further, by the ON-OFF control, the heat transfer area of the outdoor heat exchanger (3), which is one factor for determining the capacity of the outdoor heat exchanger, is reduced to 0.
Switching valve (9a) (9b) that switches the function of the outdoor heat exchanger (3) to the heat release or heat absorption function
Is ON-OFF controlled based on the cooling / heating ratio of the cooling / heating signal transmitted by the room thermo.

In addition, switching valves (14a) to (14c) provided in the high-pressure gas refrigerant pipe (11) for switching between the cooling and warming operation modes of the indoor heat exchangers (6a) to (6c), and the low-pressure gas refrigerant pipe (12 The switching valves (15a) to (15c) provided in (1) and (2) are individually controlled by a control device that has received the cooling / heating signals transmitted from each room thermo.

[Problems to be solved by the invention]

Since the conventional cooling / heating mixed type multi-room air conditioner is configured as described above, control wiring for controlling various devices goes back and forth between the indoor and outdoor units, and wiring of the control circuit becomes complicated. It takes time for wiring work or incorrect wiring.

In addition, the number of rotations of the compressor that determines the capacity of the compressor is controlled based on the ON / OFF signal of the cooling / warming of each room thermostat, and the outdoor blower, which is one factor that determines the capacity of the outdoor heat exchanger, is controlled. The number of rotations is controlled based on the outside air temperature, or the heat radiation or heat absorption function of the outdoor heat exchanger is switched and controlled based on the signal transmitted by each room thermometer. Because it cannot control environmental changes such as weather and climate,
In addition, it takes time for various components of the refrigeration cycle to balance, and each room temperature is not easily stabilized at the target temperature.

Furthermore, when changing the cooling / warming specifications of each indoor unit or increasing or decreasing the load that disrupts the load balance of the entire refrigeration cycle, the control circuit program must be changed and complicated wiring repair work must be performed. Was.

The present invention has been made in order to solve the above-described problems, and the control wiring of various devices does not move between the indoor unit and the outdoor unit, the wiring circuit is simple, and the wiring work is completed in a short time. In addition to the above, the load on the outdoor unit changes due to changes in environmental conditions such as weather and climate, and the indoor unit opens and closes by opening and closing the indoor door, changing the indoor set temperature, and switching between the cooling and heating operation modes. Even if the load on the refrigeration cycle changes due to a change in the load on the refrigeration cycle or a change in the specifications of each indoor unit or a change in the number of indoor units, the increase or decrease in the number of indoor units・ It is possible to obtain a highly reliable cooling / heating mixed-type multi-room air conditioner in which specifications can be changed easily, the refrigeration cycle is quickly balanced, and each room temperature is quickly and accurately stabilized. The interest.

[Means for solving the problem]

The mixed cooling / heating multi-room air conditioner according to the present invention has an outdoor unit having a variable capacity compressor, an outdoor heat exchanger, and an outdoor blower, an indoor unit having a plurality of indoor heat exchangers, A high-pressure liquid refrigerant pipe connected to one end of the outdoor heat exchanger and the other end to one end of each of the plurality of indoor heat exchangers via an electronic expansion valve, and one end connected to the discharge side of the compressor and a radiation switching valve A high-pressure gas refrigerant pipe connected to the other end of the outdoor heat exchanger via a first solenoid on-off valve via a first solenoid on-off valve, A low-pressure gas connected to the other end of the outdoor heat exchanger via a suction side of the heat exchanger and a heat absorption switching valve, and the other end connected to the other end of the plurality of indoor heat exchangers via a second electromagnetic on / off valve, respectively. In a cooling / heating mixed type multi-room air conditioner equipped with a refrigerant pipe, A first detector that detects a characteristic value corresponding to the discharge refrigerant pressure Pd of the compressor, a second detector that detects a characteristic value corresponding to the suction refrigerant pressure Ps of the compressor, and the first detector. Detection result P of the detector and the second detector
d, comparing the first target value Pd ^theta, and a second target value Ps ^theta previously set as ^{Ps, ΔPd = Pd θ -Pd,} ΔPs = Ps θ -P
s and calculate the required capacity of the compressor and the outdoor heat exchanger according to the calculation results ΔPd and ΔPs. (Where a, b, c, and d are positive constants), and based on the calculation result, control the capacity Δθcomp of the compressor and determine the capacity ΔAKc of the outdoor heat exchanger. An outdoor unit control device for controlling the rotation speed Kc and the heat transfer area A of the outdoor blower is provided.

[Action]

In the present invention, the characteristic values corresponding to the discharge refrigerant pressure and the suction refrigerant pressure of the compressor, the first target value, and the second
, The required capacity of the compressor and the outdoor heat exchanger is calculated based on the comparison result, the capacity of the compressor is controlled based on the calculation result, and the capacity of the outdoor heat exchanger is determined. The number of rotations of the outdoor blower is controlled, and the load of the entire refrigeration cycle is balanced by arithmetic control of only the outdoor unit-side device.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a refrigerant circuit diagram of a mixed cooling / heating multi-room air conditioner according to the present invention, where (101) shows an outdoor unit and (102) shows an indoor unit composed of a plurality of heat exchangers. The outdoor unit (101) includes a compressor (103), a high / low pressure heat exchange accumulator (104), an outdoor heat exchanger (105), a fan (106) serving as an outdoor blower, a compressor capacity control means (107),
And an outdoor unit control device (108),
A high-pressure gas pipe refrigerant distribution (10
9), high-low pressure heat exchange accumulator from intake port (104)
The low-pressure gas refrigerant pipe (111) and the high-pressure liquid refrigerant pipe (110) at the bottom of the high / low pressure heat exchange accumulator (104) are connected to the indoor unit (102) via the. In addition, a discharge pressure detector (a first pressure detector) which is provided in the middle of the high pressure gas refrigerant pipe (109) of the outdoor unit (101) and detects a characteristic value corresponding to the discharge refrigerant pressure of the compressor (103). 119), compressor (103) and accumulator (10
4) installed in the middle of the low-pressure gas refrigerant pipe (111),
A suction pressure detector (120) as a second detector for detecting a characteristic value corresponding to a suction refrigerant pressure of the compressor (103) is provided. The outdoor heat exchanger (10) connected to the high-pressure gas refrigerant pipe (109) for guiding the refrigerant gas discharged from the compressor (103)
5) A radiation switching valve that is provided on the inlet side pipe during the heat radiation operation, stops the flow of refrigerant during the heat absorption operation of the outdoor heat exchanger, and adjusts the flow rate of the refrigerant to the outdoor heat exchanger according to the opening during the heat radiation operation. An electromagnetic switching valve (116z), and an outlet side piping and a compressor (10
The pipe is connected to the low-pressure gas refrigerant pipe (111), which is the suction pipe for introducing the refrigerant gas of 3), and stops the flow of the refrigerant during the heat radiation operation of the outdoor heat exchanger (105), and stops the outdoor flow during the heat absorption operation. An electromagnetic switching valve (117z), which is a heat absorbing switching valve that adjusts the flow rate of the refrigerant to the heat exchanger (105) according to the opening, is provided, and the outdoor heat exchanger (105) connected to the high-pressure liquid refrigerant pipe (110) is provided. ), The outlet pipe during the heat dissipation operation (the inlet pipe during the heat absorption operation) has an electronic expansion valve (11
8z).

In addition, each indoor heat exchanger (1
12) to (115) are each connected to a high-pressure gas refrigerant pipe (10
The first solenoid on-off valves (116a) (116b) (116) so that the flow path of the low pressure gas refrigerant pipe (111) and the low pressure gas refrigerant pipe (111) can be selected.
c) (116d) and the second solenoid on-off valve (117a) (117b)
(117c) and (117d) are connected to each other, and the other is connected to a high-pressure liquid refrigerant pipe (110) via electronic expansion valves (118a) to (118d).

Next, the operation will be described with reference to FIG. In the indoor unit (102), the heating mode is only the heat exchanger (112),
When the cooling mode is operated simultaneously with the three heat exchangers (113) and (115), the flow of the refrigerant is indicated by solid arrows. On the refrigeration cycle, the ratio of one evaporator to one condenser becomes the ratio, and the high pressure Pd and the low pressure Ps deviate from the target value. The high pressure Pd becomes higher than the target high pressure Pd ^θ , and the low pressure Ps becomes It becomes higher than the target low pressure Ps ^θ .

By the way, assuming that the change in the high-pressure pressure is ΔPd and the change in the low-pressure pressure is ΔPs with respect to the compressor capacity change Δθcomp, ΔPd = a · Δθcomp, ΔPs = −bΔθcomp, a> o, b
> O, and the change ΔAK of the product AK of the heat transfer area A and the heat transfer rate K of the outdoor heat exchanger is compared with the change ΔPd of the high pressure pressure −−c · Δ
AKc, the change in low-pressure pressure ΔPs = −d · ΔAKc (c indicates the case where the condenser is used as a condenser), and is expressed by the following equation according to the superposition operation.

ΔPd = a · Δθcomp−cΔAKc ΔPs = −bΔθcomp−dΔAKc By taking the inverse matrix, Becomes

According to the above equation (1), the deviation between the target high pressure Pd ^θ and the value Pd of the discharge pressure detector (119) is ΔPd, and the target low pressure Ps
Let ΔPs be the difference between ^θ and the value Ps of the suction pressure detector (120), and if the calculation is performed by the controller (108), the capacity change amount Δθcomp of the compressor (103) and the heat exchange of the outdoor heat exchanger (105) The capacity change amount ΔAKc is obtained, and based on these calculation results, the compressor (103) that determines the capacity of the compressor is controlled, and the maximum factor that determines the capacity of the outdoor heat exchanger (105) is determined. The rotation speed of the outdoor blower (106) and the opening degree of the electromagnetic switching valve (116z) for determining the heat radiation capacity of the outdoor heat exchanger;
Alternatively, one of the degrees of opening of the electromagnetic switching valve (117z) that determines the heat absorption capacity of the outdoor heat exchanger (105) is controlled. In the above embodiment, the calculation is performed based on the deviation between the target high pressure and the pressure detected by the discharge pressure detector (119), and the deviation between the target low pressure and the pressure detected by the suction pressure detector (120). A deviation value between a target condensing temperature corresponding to the target high pressure saturation temperature and a detected temperature of the first detector that detects the condensing temperature of the high pressure gas refrigerant pipe (109);
Compressor (103) and outdoor heat exchange based on a deviation value between a target evaporation temperature corresponding to the saturation temperature of the target low pressure and a detection temperature of a second detector that detects an evaporation temperature of low pressure gas refrigerant pipe (111). The same effect can be obtained by calculating the required capacity of the container (105).

Further, in the above embodiment, in order to determine the capacity of the outdoor heat exchanger (105), the rotation speed of the outdoor blower (106), the opening degree of the electromagnetic switching valve (116z), or the electromagnetic switching valve (117z)
The opening degree of each of the solenoid-operated switching valves (116z) and (117z) is fixed, and only the rotation speed of the outdoor blower (106) is controlled. Good.

〔The invention's effect〕

As described above, according to the present invention, the detection results of the first detector and the second detector are compared with the first target value and the second target value set in advance, and compression is performed based on the comparison results. Calculating the required capacity of the heat exchanger and the outdoor heat exchanger, controlling the capacity of the compressor based on the calculation result, and controlling the rotation speed of the outdoor blower that determines the capacity of the outdoor heat exchanger. Therefore, it is possible to quickly respond to a large change in the load on the indoor unit side. In addition, since the load of the entire refrigeration cycle is balanced by the arithmetic control of only the outdoor unit-side devices, the control wiring of various devices does not move between the indoor and outdoor units, and the wiring circuit is simple and the wiring is simple. Work can be completed in a short period of time, and the load on the outdoor unit changes due to changes in environmental conditions such as weather and climate.In addition, opening and closing of indoor doors, changing indoor set temperatures, and cooling / heating operation modes Even if the load on the indoor unit changes due to switching, or if the cooling / heating ratio of the entire refrigeration cycle changes due to changes in the specifications or increase / decrease construction of each indoor unit, it is necessary to follow these changes. It is easy to increase / decrease and change the specifications of indoor units, and the refrigeration cycle is quickly balanced, and each indoor temperature is speedy and stable with high reliability. Warm Mixed multi-room air conditioner is obtained.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of a mixed cooling / heating multi-room air-conditioning apparatus according to one embodiment of the present invention, FIG. 2 is a flow chart of the refrigerant in FIG. 1, and FIG. 3 is a refrigerant in a conventional multi-room cooling / heating apparatus. It is a circuit diagram. (101) is an outdoor unit, (102) is an indoor unit, (10
3) is a compressor, (104) is a high and low pressure heat exchange accumulator, (105) is an outdoor heat exchanger, (107) is compressor capacity control means, (108) is an outdoor unit controller, and (109) is high pressure gas. Refrigerant pipe, (110) is a high-pressure liquid refrigerant pipe, (111) is a low-pressure gas refrigerant pipe, (112) to (115) are indoor heat exchangers,
6a) to (116d), (117a) to (117d) are solenoid on-off valves,
(118a) to (118d) are electronic expansion valves, (116z) and (117z) are electromagnetic switching valves, (118z) is an electronic expansion valve, (119) is a discharge pressure detector, and (120) is a suction pressure detector. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Claims] 1. An outdoor unit having a variable capacity compressor, an outdoor heat exchanger, and an outdoor blower, an indoor unit having a plurality of indoor heat exchangers, one end being connected to one end of the outdoor heat exchanger, One end of the outdoor heat exchanger is connected to one end of each of the plurality of indoor heat exchangers via an electronic expansion valve, and one end of the outdoor heat exchanger is connected to the discharge side of the compressor and a radiation switching valve. At the other end, a high-pressure gas refrigerant pipe, the other end of which is connected to the other end of the plurality of indoor heat exchangers via the first electromagnetic on-off valve, and one end of which is connected to the suction side of the compressor and an endothermic switching valve. And a low-pressure gas refrigerant pipe having the other end connected to the other end of the outdoor heat exchanger and the other end connected to the other end of the plurality of indoor heat exchangers via a second electromagnetic on-off valve. Corresponds to the refrigerant pressure Pd discharged from the compressor in a multi-room air conditioning system A first detector for detecting a characteristic value corresponding to the suction refrigerant pressure Ps of the compressor, a second detector for detecting a characteristic value corresponding to the suction refrigerant pressure Ps of the compressor, and detection of the first detector and the second detector. The results Pd, Ps and a preset first target value P
d ^θ and the second target value Ps ^θ, and ΔPd = Pd ^θ
−Pd, ΔPs = Ps ^θ −Ps, and these calculation results ΔPd,
The required capacity of the compressor and the outdoor heat exchanger is calculated by ΔPs (Where a, b, c, and d are positive constants), and based on the calculation result, control the capacity Δθcomp of the compressor and determine the capacity ΔAKc of the outdoor heat exchanger. An air-conditioning / cooling type multi-room air conditioner, comprising: an outdoor unit control device for controlling the rotation speed Kc and the heat transfer area A of the outdoor blower.