JP2893844B2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention connects an outdoor unit and a plurality of indoor units with two refrigerant pipes, and sets the operation mode of each indoor unit to a mixture of cooling and heating. The present invention relates to autonomous decentralized cooperative control of simultaneous cooling and heating multi-air conditioners.

[Prior Art] FIG. 5 is a configuration diagram showing a conventional multi-room air conditioner described in, for example, Japanese Patent Laid-Open No. 1-302074, in which (1) is an outdoor unit and (2) is an outdoor unit. Is a variable capacity compressor,
(3) is a four-way valve, (4) is an outdoor heat exchanger, (5) is an outdoor expansion valve, (6a), (6b), (6c) are indoor units, (8)
a), (8b) and (8c) are indoor heat exchangers, (9) is an outdoor fan, (10a), (10b) and (10c) are indoor fans, (11) is a header, and (12a). , (12b) and (12c) are indoor first two-way valves, (13a), (13b) and (13c) are indoor second two-way valves, and (14a), (14b) and (14c) are chambers. An inside first expansion valve, (15a), (15b), and (15c) are indoor-side second expansion valves, (16) is a two-way valve, and (50) is a control device for controlling the air conditioner. Next, the operation will be described. The high-temperature and high-pressure gas refrigerant compressed by the compressor (2) passes through the four-way valve (3), partially condenses and liquefies in the outdoor heat exchanger (4), and becomes a medium-pressure two-phase refrigerant as the outdoor expansion valve (5). ) To be sent indoors. When the indoor unit (6a) is in the heating mode and the indoor units (6b) and (6c) are in the cooling mode, the medium-pressure two-phase refrigerant sent indoors passes through the indoor-side first two-way valve (12a). Condensed and liquefied in the indoor heat exchanger (8a), and the indoor second expansion valve (15
After a), it is collected as a liquid in the header (11). This medium-pressure liquid refrigerant is supplied to the indoor first expansion valves (14) of the indoor units (6b) and (6c).
a) and (14c) to enter the indoor heat exchangers (8b) and (8c), respectively.
Return to the outdoor unit (1) via the two-way valves (13b) and (13c). Then, the refrigerant returns to the compressor (2) again via the four-way valve (3), and a refrigerant cycle is formed. Various devices forming the refrigerant cycle are controlled as follows by a control device (50) provided on the outdoor unit (1) side. The capacity of the compressor (2) on the outdoor unit (1) side is from the indoor units (6a) to (6).
c) Room thermo provided in each room on the side (not shown)
Is controlled based on the ON-OFF signal transmitted by the outdoor heat exchanger (4), and the factor that determines the capacity of the outdoor heat exchanger (4) is only the air blower of the outdoor blower (9). It is controlled by a temperature deviation value between an outside air temperature detected by an outside air thermometer (not shown) provided in (1) and a preset temperature. The four-way valve (3) that switches the function of the outdoor heat exchanger (4) to the heat radiation or heat absorption function is provided by the total ratio of the cooling / heating signals transmitted by each room thermo on the indoor units (6a) to (6c). And the indoor first and second two-way valves (12a) to (12a) for switching between the cooling and warming operation modes of the indoor heat exchangers (8a) to (8c).
c), (13a) to (13c) and the inlet / outlet expansion valve (14a) to
(14c) and (15a) to (15c) are individually controlled by cooling / warming signals transmitted by each room thermo. Japanese Patent Application Laid-Open No. 2-8663 discloses an almost identical prior art in which an outdoor unit and an indoor unit are connected by two pipes.

[Problems to be Solved by the Invention] Since the conventional multi-room air conditioner is configured as described above, in order to control various devices, control signal wiring moves back and forth between the indoor-outdoor engine and the control. The wiring work of the circuit becomes complicated, the wiring work takes time, the wiring is incorrect, and the capacity of the outdoor heat exchanger is controlled by the outside air temperature only by the factor of the rotation speed of the outdoor blower, Since the control of various devices is not related to each other, but is controlled individually by the signals of the control devices, it is not possible to follow changes in environmental conditions such as weather and climate on the outdoor unit side, or the refrigeration cycle It takes time to balance the entire load, and the temperature of each room is not stable at the set cooling / heating temperature.In addition, specifications change of each indoor unit that breaks the load balance of the entire refrigeration cycle. Increase / decrease construction
There was a problem that it was necessary to change the program of the control circuit and perform complicated wiring repair work.

The present invention has been made in order to solve the above-described problems, and the load on the outdoor unit changes due to changes in environmental conditions such as weather and climate, and the opening and closing of the indoor door on the indoor unit side. The load on the indoor unit changes due to the change of the indoor set temperature and the operation switching of the cooling / heating operation mode, and the total cooling / heating capacity of the entire refrigeration cycle due to the specification change / increase / decrease work of each indoor unit. Even if the ratio changes, the load of the entire refrigeration cycle is autonomously balanced by batch simultaneous operation control of only the outdoor unit side equipment in response to this changed load, the control circuit is simple, and the specifications of each indoor unit It is an object of the present invention to provide a highly reliable autonomous decentralized multi-room air conditioner that can easily be changed or increased / decreased in construction and can stably and accurately balance the load of the entire refrigeration cycle.

[Means for Solving the Problems] A multi-room air conditioner according to the present invention includes an outdoor unit having a variable capacity compressor, a four-way valve, an outdoor heat exchanger, and an outdoor blower, and two pipes connected to the outdoor unit. A shunt controller that changes the flow of the refrigerant from the outdoor unit and an indoor unit that has a plurality of indoor heat exchangers connected in parallel via the shunt controller and piping, respectively, In a possible air conditioner, or refrigerant state detecting means arranged near the outdoor heat exchanger and the indoor heat exchanger to detect the state of the refrigerant flowing through the compressor or the outdoor heat exchanger and the indoor heat exchanger, The required capacity of the compressor and the outdoor heat exchanger is calculated by comparing the detection result detected by the refrigerant state detecting means with a preset target value, and the capacity of the compressor is controlled based on the calculated result. And adjusting the outdoor heat exchanger heat exchange capacity adjusting means,
A controller for controlling the capacity of the outdoor heat exchanger.

The refrigerant state detecting means detects the pressure of the refrigerant discharged and drawn by the compressor or the condensation temperature and the evaporation temperature of the refrigerant in the refrigeration cycle.

The control device switches the four-way valve according to the calculated required capacity of the outdoor heat exchanger, and switches the function of the outdoor heat exchanger to the heat radiation or heat absorption function.

[Operation] The air conditioner according to the present invention is provided in an outdoor unit, and the amount of refrigerant and the amount of air flowing to the outdoor heat exchanger are changed so that the heat exchange capacity of the outdoor heat exchanger can be adjusted. In the vicinity of the heat exchanger and the indoor heat exchanger, the state of the refrigerant flowing through the compressor or the outdoor heat exchanger and the indoor heat exchanger is detected, and the detection result is compared with a preset target value to determine the state of the compressor and the outdoor heat exchanger. The required capacity of the heat exchanger is calculated, the capacity of the compressor is controlled based on the calculation result, and the amount of refrigerant and the amount of air flowing in the outdoor heat exchanger provided in the outdoor unit are changed to change the capacity of the outdoor heat exchanger. Control heat exchange capacity.

Further, the air conditioner according to the present invention connects the opening and closing of the on-off valves provided at the inlet and outlet pipes of the outdoor heat exchanger, and connects the inlet and outlet pipes of the outdoor heat exchanger, and on the way. The heat exchange capacity of the outdoor heat exchanger can be continuously adjusted by opening and closing the bypass valve of the bypass pipe having the bypass valve and changing the rotation speed of the outdoor blower.

Further, the air conditioner according to the present invention detects the pressure of the refrigerant discharged and drawn by the compressor or the condensation temperature and the evaporation temperature of the refrigerant in the refrigeration cycle.

Further, the air conditioner of the present invention switches the four-way valve according to the calculated required capacity of the outdoor heat exchanger, and switches the function of the outdoor heat exchanger to the heat radiation or heat absorption function.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, (1) is an outdoor unit, (2) is a variable displacement compressor in the outdoor unit (1), (3) is a four-way valve, (4a),
(4b) is an outdoor heat exchanger connected in parallel, (6a) to (6)
c) is an indoor unit, (7) is an accumulator, (8a) to (8)
c) is an indoor heat exchanger, (12a) to (12c) are electronic expansion valves connected to one ends of the indoor heat exchangers (8a) to (8c),
(17), (18) are connecting pipes connecting the outdoor unit (1) and the flow dividing controller (19), (20) is a high pressure pipe section in the flow dividing controller (19), (21) is a low pressure pipe section, (22) is a medium pressure pipe section, (23) is an electronic expansion valve, (24a) to (24c), (25)
a) to (25c) are solenoid on-off valves. Each of the indoor units (6a) to (6c) is connected to each of the indoor units (6a) to (6c) by two pipes, and each of the indoor units (6a) to (6c) is connected to each of the indoor units (6a) to (6c) by two pipes. Yes, each indoor unit (6a) ~
One end of (6c) is connected to the medium pressure pipe (22) of the shunt controller (19) via the electronic expansion valves (12a) to (12c), respectively, and the other end is an electromagnetic on-off valve of the shunt controller (19), respectively. (24a) to (24c) and (25a) to (25c) are connected to the high-pressure pipe (20) and the low-pressure pipe (21).

(26a), (26b), (27a) and (27b) are on-off valves connected to both sides of each outdoor heat exchanger (4a) and (4b),
(28) is a bypass provided in parallel with the outdoor heat exchangers (4a) and (4b), and (29) is a bypass opening / closing valve provided in the bypass (28).

Further, (30) is a high pressure detector provided on the refrigerant discharge side of the variable capacity compressor (2) and detects the pressure Pd thereof, and (31) is a refrigerant inlet side of the accumulator (7). A low pressure detector corresponding to a second detector for detecting the pressure Ps of the four-way valve (3) based on the detection output of the high pressure detector (30) and the low pressure detector (31) , Outdoor blower (9), on-off valve (26a), (26b), (27a),
(27b) A control device for controlling the bypass on-off valve (29). (33) is a four-way valve.

In the air conditioner having such a configuration, the indoor unit (6a)
The operation when the operation mode is the heating operation mode and the indoor units (6b) and (6c) are in the cooling operation mode will be described.

The high-temperature and high-pressure gas refrigerant compressed by the compressor (2) in the outdoor unit (1) passes through the four-way valve (3) and passes through the outdoor heat exchanger (4).
Partially condensed in (a) and (4b) and turns into a two-phase refrigerant and enters the indoor branch flow controller (19) via the high-pressure communication pipe (17). Here, the high-pressure gas refrigerant separated by the gas-liquid separator (40) flows into the indoor unit (6a) from the solenoid on-off valve (25a) through the high-pressure gas pipe (20), and the indoor heat exchanger (8a) Served for heating. Thereafter, the refrigerant flows into the medium pressure pipe (22) via the electronic expansion valve (12a). This refrigerant merges with the refrigerant flowing from the liquid layer portion of the gas-liquid separator (40) to the medium pressure pipe portion (22) via the electronic expansion valve (23), and the indoor units (6b), (6)
into c). The electronic expansion valves (12b), (12
The pressure becomes low in (c) and is cooled by the indoor heat exchangers (8b) and (8c) and gasified, and then the solenoid on-off valves (24b) and (24c)
And joins the low-pressure pipe section (21) via the flow controller (19)
And enter the outdoor connection pipe (18). Then, the refrigerant passes through the four-way valve (3) of the outdoor unit (1) and the accumulator (7) and circulates again to the compression unit (2) to form a simultaneous cooling / heating refrigerant circuit.

In the above refrigerant circuit, the heat exchanger (8a) of the indoor unit (6a) acts as a condenser, and the heat exchangers (8b) and (8c) of the indoor units (6b) and (6c) act as evaporators. doing.

In the operation as described above, the load on the outdoor unit side changes depending on environmental conditions such as weather and climate, the opening and closing of the indoor doors on each indoor unit side (6a) to (6c), and the setting of the indoor set temperature. The load on the indoor unit side changes due to setting changes and switching between the cooling and heating modes, and furthermore, the total cooling and cooling of the entire refrigeration cycle
Even if the heating capacity ratio changes, the capacity of the compressor (2) on the outdoor unit side (1) is controlled to follow the changed load and balance the load of the entire refrigeration cycle. The degree of opening of the bypass valve (29), which determines the capacity of the outdoor heat exchanger (26), and the on-off valves (26a), (27a), (26)
It is necessary to selectively control the opening degrees of b) and (27b) and the air volume of the outdoor blower (9). Further, depending on the change ratio of the total cooling / heating capacity required by the outdoor unit and each indoor unit, a four-way valve (3) that switches the function of the outdoor heat exchanger from the heat radiation function to the heat absorption function and from the heat absorption function to the heat radiation function. Also needs to be controlled. In this embodiment, a signal indicating the high pressure Pd detected by the high pressure detector (30) and a signal indicating the low pressure Ps detected by the low pressure detector (31) are transmitted to the control device (32).
In general, the higher the compression function, the higher the pressure
Pd rises and low pressure Ps falls. When the evaporator capacity is increased, both the high pressure Pd and the low pressure Ps increase, and conversely, when the condenser capacity is increased, both the high pressure Pd and the low pressure Ps decrease. If the high pressure Pd and the low pressure are in a steady state maintaining a constant value, it means that the heat exchange capacity between the indoor side and the outdoor side is balanced, so that these high pressure Pd and the low pressure Ps are changed to a predetermined target high pressure
Outdoor unit (1) so that Pd ^* and target low pressure Ps ^*
By controlling the heat exchange capacity of the outdoor unit, closed autonomous control can be performed in the outdoor unit (1).変 更 Qcomp,
When the change amount of the heat exchange capacity Ak ₀ of the outdoor heat exchanger is set to △ Ak ₀ , the relationship between Pd and Ps described above is expressed by the following equation (1).

Here, a, b, c, and d are constants determined in advance, and △ Pd and △ Ps are deviations from target values, that is, △ Pd = Pd
^* -Pd, △ Ps = Ps ^* -Ps. By transforming equation (1), Becomes

The capacity control of the compressor (2) is performed based on the thus obtained ら れ Qcomp. Also, based on the determined △ Ak ₀ , the four-way valve (3) is controlled by judging whether to use the outdoor heat exchangers (4a) and (4b) as condensers and use them as heat radiation sources or as evaporators and use them as heat absorption sources. I do. For example, in the above operation state, when the heat exchange capacity obtained by the previous heat exchange capacity and the required heat exchange capacity is positive, the outdoor heat exchangers (4a) and (4b) are directly condensed. When it becomes negative, the cycle is made with the outdoor heat exchangers (4a) and (4b) as evaporators. The variable control of the heat exchange capacity (AKe when positive, AKc when negative) in the cycle is performed by controlling the rotation speed of the outdoor blower (9) and the on-off valves (26a), (2
6b), (27a), (27b), and the opening and closing control of the bypass valve (29). That is, the selection of the outdoor heat exchanger to be operated according to the required heat exchange capacity and the determination of the necessity of bypassing the refrigerant by the bypass passage (28) are performed, and the rotation speed of the outdoor blower (9) at that time is varied. Thus, the heat exchange capacity is continuously controlled. FIG. 2 shows a control block diagram in such control.

For example, when used as an outdoor heat exchanger (4a) or (4b) condenser, the outdoor heat exchanger (4a) depends on the required heat exchange capacity.
a), (4b) Both use, only the outdoor heat exchanger (4b), or use the outdoor heat exchanger while partially bypassing the refrigerant by the bypass path (28), each opening and closing The valves (26a), (26b), (27a), (27b) and the bypass valve (29) are opened and closed, and the rotational speed of the outdoor blower (9) is controlled. Fig. 3 shows the relationship between the rotational speed of the outdoor blower and the heat exchange capacity of the condenser in each case. When both the outdoor heat exchangers (4a) and (4b) were used, only the outdoor heat exchanger (4b) was used. When AKc is used, AKc also decreases in the order of bypassing by the bypass path (28),
In each case, AKc continuously changes with respect to the rotation speed of the outdoor blower (9).

In this way, the capacity of the compressor is controlled, and the capacity of the outdoor heat exchanger is linearly controlled from 0 to 100% by controlling various devices that determine the capacity of the outdoor heat exchanger. , The autonomous capacity control can be performed in the outdoor unit (1).

FIG. 4 shows the refrigerant condensation temperature CT and evaporation temperature ET in the entire air conditioner instead of the high pressure Pd and the low pressure Ps.
FIG. 3 is a configuration diagram in the case of detecting an external unit and controlling the outdoor unit (1). (34) is a refrigerant temperature sensor provided in each of the indoor units (6a) to (6c), and (35) controls the electronic expansion valves (12a) to (12c) based on the detected temperature of the refrigerant temperature sensor (34). A microcomputer for performing autonomous control of each of the indoor units (6a) to (6c), and (36) is a temperature sensor provided in the outdoor heat exchanger (4b). In this case, the refrigerant temperature sensor (34), in the temperature detected by the temperature sensor (36), condensing the largest one temperature CT, the smallest and the evaporation temperature ET, respectively target condensing temperature CT ^*, the target evaporation temperature ET ^* Deviation from △ CT, △ E
It sought T, the following equation △ qcomp, the △ AK ₀ calculated the high-pressure Pd, as in the case of low pressure Ps, Similarly, the heat exchange capacity may be controlled. In this case, for example, there is a method of selecting the maximum and minimum temperatures on the indoor side by the microcomputer (35) or the like, transmitting this to the outdoor side, and comparing it with the detected temperature on the outdoor side. In addition, one signal transmission path is required. However, a temperature sensor is more cost-effective than a pressure detector. Further, the control may be performed by combining a pressure sensor and a temperature sensor.

[Effects of the Invention] A multi-room air conditioner of the present invention includes an outdoor unit having a variable capacity compressor, a four-way valve, an outdoor heat exchanger, and an outdoor blower,
An indoor unit having a branch controller connected to the outdoor unit via two pipes and changing a flow of the refrigerant from the outdoor unit, and a plurality of indoor heat exchangers connected in parallel with the branch controller and the pipes, respectively. An air conditioner capable of simultaneously operating cooling and heating, comprising: an opening / closing valve provided on the outdoor unit and provided on each of an inlet side pipe and an outlet side pipe of the outdoor heat exchanger; and the outdoor heat exchanger. By connecting the inlet and outlet pipes, and by opening and closing the bypass valve of the bypass pipe having a bypass valve in the middle, and by changing the number of revolutions of the outdoor blower, the amount of refrigerant and the amount of air flowing to the outdoor heat exchanger are changed. An outdoor heat exchanger heat exchange capacity adjusting means capable of continuously adjusting the heat exchange capacity of the outdoor heat exchanger,
Refrigerant state detecting means arranged near the compressor or the outdoor heat exchanger and the indoor heat exchanger for detecting the state of refrigerant flowing through the compressor or the outdoor heat exchanger and the indoor heat exchanger; and the refrigerant state detecting means Comparing the detected result of the detected and a preset target value to calculate the required capacity of the compressor and the outdoor heat exchanger, and controlling the capacity of the compressor based on the calculated result, The outdoor heat exchanger heat exchange capacity adjusting means is adjusted, and a control device for controlling the capacity of the outdoor heat exchanger is provided. Even if the load on the indoor unit changes or the total cooling / heating capacity of the entire refrigeration cycle changes due to changes in the specifications or increase / decrease construction of each indoor unit, etc., the load on the entire refrigeration cycle is balanced and the control circuit can be easily implemented. Having that effect.

Further, since the refrigerant state detecting means is configured to detect the pressure of the refrigerant discharged and sucked by the compressor or the condensation temperature and the evaporation temperature of the refrigerant in the refrigeration cycle, a highly reliable air conditioner can be obtained by simple measurement. Has an effect. In addition, the control device is configured to switch the four-way valve according to the calculated required capacity of the outdoor heat exchanger and switch the function of the outdoor heat exchanger to the heat radiation or heat absorption function. The arithmetic control makes it possible to autonomously stabilize the load balance of the entire refrigeration cycle with high speed and accuracy, and to obtain a reliable Noda air conditioner.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a multi-room air conditioner according to one embodiment of the present invention, FIG. 2 is a control block diagram, FIG. 3 is an explanatory diagram for explaining the operation control thereof, and FIG. 4 is another invention. FIG. 5 is a block diagram showing a multi-room air conditioner according to the embodiment of the present invention. In the figure, (1) is an outdoor unit, (6a) to (6c) are indoor units, (8a) to (8c) are indoor heat exchangers, and (12a) to (12c).
Is an electronic expansion valve, (17) and (18) are communication pipes, (19) is a diversion controller, (20) is a high-pressure pipe, (21) is a low-pressure pipe, (22) is a medium-pressure pipe, and (24a). ~ (24c), (25a) ~
(25c) is a solenoid on-off valve, (26a), (26b), (27a),
(27b) is an on-off valve, (28) is a bypass, (29) is a bypass valve, (30) is a high pressure detector, (31) is a low pressure detector,
(32) is a control device, (34) is a refrigerant temperature sensor, (36)
Is a temperature sensor. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (3)

(57) [Claims] 1. An outdoor unit having a variable capacity compressor, a four-way valve, an outdoor heat exchanger, and an outdoor blower, and a diversion connected to the outdoor unit by two pipes to change a flow of a refrigerant from the outdoor unit. An air conditioner comprising: a controller; and an indoor unit having a plurality of indoor heat exchangers connected in parallel to each other through a pipe with the branch flow controller. Opening and closing of on-off valves provided on each of the inlet and outlet pipes of the heat exchanger, and connecting the inlet and outlet pipes of the outdoor heat exchanger,
Opening and closing a bypass valve of a bypass pipe having a bypass valve in the middle, and a change in the number of revolutions of the outdoor blower, changing the amount of refrigerant and the amount of air flowing to the outdoor heat exchanger by changing the heat exchange capacity of the outdoor heat exchanger. An outdoor heat exchanger heat exchange capacity adjusting means which can be continuously adjusted, and which is arranged near the compressor or the outdoor heat exchanger and the indoor heat exchanger and flows through the compressor or the outdoor heat exchanger and the indoor heat exchanger. Refrigerant state detection means for detecting the state of the refrigerant, and calculates the required capacity of the compressor and the outdoor heat exchanger by comparing a detection result detected by the refrigerant state detection means and a preset target value, A controller that controls the capacity of the compressor based on the calculation result, adjusts the outdoor heat exchanger heat exchange capacity adjusting means, and controls the capacity of the outdoor heat exchanger. Toss Multi-room type air conditioner. 2. A multi-chamber air conditioner according to claim 1, wherein said refrigerant state detecting means detects a pressure of refrigerant discharged and sucked by said compressor or a condensation temperature and an evaporation temperature of refrigerant in a refrigeration cycle. Machine. 3. The control device according to claim 1, wherein the control device switches the four-way valve according to the calculated required capacity of the outdoor heat exchanger, and switches the function of the outdoor heat exchanger to the heat radiation or heat absorption function. Multi-room air conditioner.