JPS5885041A - Air conditioning system - Google Patents

Abstract

PURPOSE:To permit the most suitable operation at all times by a method wherein the operating number of a plurality of indoor units connected to one set of outdoor unit is detected to control the capacity control mechanism of a compressor based on a predetermined control factor in accordance with the number of the operating units. CONSTITUTION:In the air conditioning system, in which four sets of indoor units A D are connected to one set of outdoor unit, the outdoor unit is consisting of the compressor 1 having the capacity control mechanism, a circuit switching valve 20S, an outdoor coil 2, an expansion mechanism 3 for heating, a liquid receiver 5 and accumulators 6,7 accommodated therein. Said capacity control mechanism is controlled by a method wherein an opening and closing valve 72 is interposed in a bypassing path 71, connecting the intermediate part of a compression stroke in the cylinder chamber 1a of the compressor 1 and the suction side thereof, and the same valve 72 is controlled by a solenoid valve 20RS in an operating circuit. The solenoid valve 20RS controlls the system in accordance with the operating number of the indoor units A D when it is below a predetermined operating number while the valve 20RS controlls the system in accordance with the pressure of a refrigerant medium when the operating number is larger than the predetermined operating number.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air conditioner, and more particularly to an air conditioner in which several indoor units each having an indoor coil are connected to one outdoor unit having an electric heater.

Generally, in this type of air conditioner, a capacity control mechanism is provided on the compression side, and the capacity side m1c is adjusted in response to a decrease in load.
A mechanism is operated to perform a local unloading system that limits the compression capacity to a small capacity.

On the other hand, as a method for operating the capacity control mechanism according to the load, a method is known in which a pressure detector for detecting low pressure is used and the mechanism is operated according to a decrease in the low pressure to perform the unload control. By the way, when using this method, in order to avoid repeating the start and stop of compression, the loading operation and unloading operation is switched from the unloading operation to the loading operation when the pressure is 5.51, and the loading operation is switched to the loading operation when the low pressure is 6.51. The device is configured to switch from to unloading operation.

For this reason, the number of operating indoor units decreases, and the low pressure that requires unloading, for example, 3.6~
Even if the time reaches 3.7~, road operation will continue2.

In this case, compared to road operation where the low pressure is 5.51 or higher, the refrigerant circulation amount decreases by 40^50%, the temperature of the compressor motor coil increases, and the motor coil burns out. It occurs.

To solve this problem, it is possible to raise the set value of the pressure detector, but in this case, the operating range of the unloading operation will be expanded, in other words, the operating time of the unloading operation will be longer, and the indoor cooling The problem arises that the effect becomes worse,
It does not solve the problem mentioned above.

On the other hand, the capacity control 1a is performed according to the number of operating indoor units.
Methods of operating the II structure are also known.

For example, if four indoor units are connected, 6.
If 4 units are in load operation and 1.2 units are in unload operation, when 3 units are in operation and the load is low, the low pressure will drop and frost will form on the coil that serves as the evaporator. The input to the compressor increases due to the low pressure drop, resulting in power loss.
If you control 1 to 3 indoor units to perform unloading operation, the operating range of unloading operation will expand, and for example, when starting 3 indoor units at the same time, you will be able to quickly cool down or cool down quickly. It is not possible.

The present invention focuses on the problems of the capacity control method using low pressure and the capacity control method using the number of indoor units in operation, and has been made to solve each of the above problems. The capacity control method can be controlled to match the number of operating indoor units connected to the tabletop and the load conditions, and the system can be controlled at all times without burning out the compression motor coil or causing frost on the evaporator coil. The purpose of the present invention is to provide an air conditioner that can be operated under optimal conditions.The present invention utilizes the advantages of the compression capacity control method based on refrigerant pressure and the capacity control method based on the number of units in operation, and performs each of the above-mentioned controls. This system was developed to solve the W4WA problem of the system, and is equipped with a pressure detector that measures the number of indoor units in operation, and when the capacity control mechanism is set to a predetermined number or less, the pressure sensor detects the number of indoor units in operation. When the number of indoor units in operation exceeds a predetermined number, control is performed using a pressure signal from the pressure detector.

Next, what is shown in FIG. 1 explaining an embodiment of the air conditioner of the present invention is one outdoor unit (0) and four indoor units (A), (B), (0) I (D). , contact piping (
x ) # (li) K, a multi-room heat pump type air conditioner, which is connected to the outdoor unit) (
0) K is a rotary type pressure a11ml (1) with capacity control 1lWI & structure described later, four-way switching valve (208)
, an outdoor coil (2) that becomes a cold III condenser and an evaporator during heating, an expansion structure for heating (3), and a check valve (4).
), the delivery device (5), and the accumulators (6) and (7) are connected by internal pipes and refrigerant pipes (8), and among the pipes (8), there is a high-pressure pipe through which high-pressure liquid gastric medium flows. Liquid pipe (81
)K connects four layer-side branch pipes (82)... and connects each layer-side solenoid valve (20tI) to each of these branch pipes (82)-.
)* (20BL)e (20oL)a (20IIL
), and four gas side branch pipes (84') are connected to the low pressure gas pipe (86) through which the low pressure gas refrigerant flows, and each of these branch pipes (84) - k is connected to the gas side. Solenoid valve (20AG), (20BG)# (200G)* (
201G) is installed.

And, the liquid side branch pipe (82) - and the gas side branch pipe (84)
”)-- have check valves (9) and (10), respectively.
are connected in parallel, and the layer side branch pipe (82)
... are connected to pressure equalizing pipes (85) with check valves (11) and capillary tubes (12), and these pressure equalizing pipes (85) are connected to the heating expansion bridge ( 3) is connected to the outlet side during heating.

In addition, each indoor unit (mu)... includes a fan (shim), an indoor coil (16) that becomes an evaporator during cooling and a condenser during heating, an expansion mechanism for cooling (14), and a check valve ( 15) are installed internally, and are connected to each other by refrigerant piping (16).

Therefore, in the above configuration, by driving the pressure machine (1) and switching the four-way switching valve (20B), a cooling cycle indicated by the dotted line arrow and a heating cycle indicated by the solid line arrow are formed. In the cooling cycle, the indoor coil (16) serves as an evaporator for cooling, and in the heating cycle, it serves as a condenser.

Next, the compression (1) and its capacity side mechanism will be explained.

Compression (1) shown in FIG.
A body forming a blade (1) with a spring (1C)
1i) is slidably supported, and a suction port (1.) and a discharge port (1f) opening into the cylinder chamber (1a) are placed near the inside of the cylinder chamber (1a) by sandwiching this blade (1b). In addition, the capacity side # mechanism is an intermediate part of the compression process from the opening position of the first suction port (1・) to the opening position of the discharge port (1f) in the cylinder chamber (1&). (1g)
and a valve chamber (1g) communicating with the port (1g).
70), and a suction port (1.) is provided from the valve chamber (20).
A bypass passage (71) communicating with Ic is provided, and the valve chamber (
70) includes an on-off valve (72) that opens and closes the intermediate pressure port (1g) and the bypass passage (71), and the on-off valve (70).
2) is installed inside the spring (73) that always biases the valve in the opening direction, and the on-off valve (7'2) is opened and closed by the pressure side of the rear chamber (74) of the on-off valve (72). Shrinkage (
The capacity of 1) is controlled to be a small capacity and a full capacity.

1, one end of the first control pipe (75) is connected to the high-pressure liquid pipe (81) of the refrigerant pipe (8) connected to the compression ratio (1), and low pressure gas pipe (
83), specifically the second control pipe (76) in the suction pipe (86)
The first control tube (75) and the expansion mechanism (77) consisting of a cow tip tube are connected to the second control tube (75) and the second control tube (75).
Control pipes (76) are each provided with two three-way solenoid valves (20R8), and the other ends of the first and second control pipes (75) and (76) are connected to the on-off valve (72) by a connecting pipe (78). Back E
The high pressure of the high pressure liquid pipe (81) is connected to the rear chamber (74) to configure the operation circuit of the capacity control mechanism and close the solenoid valve (20ig). The on-off valve (72) is closed by communicating the refrigerant, and
By opening the electromagnetic valve (2011B), the back chamber (74) is communicated with the suction side and the opening/closing valve (72) is opened.
is opened, and the suction side is communicated with the high pressure liquid pipe (81)K via the expansion mechanism (77).

That is, the solenoid valve (20R8) uses an energized closed type solenoid valve, and the solenoid valve (201g) cannot be closed.
Therefore, the high-pressure refrigerant in the high-pressure liquid pipe (81) flows through the first control pipe (
75) and the on-off valve (72) via the connecting pipe (78).
flows into the rear facing chamber (74), opens against the force of the spring (73), and I! The valve (72) is pressed to close the intermediate pressure boat (1g). Therefore, the compressor (1
) is the full capacity operation that performs the compression action throughout the compression process,
In other words, it is a load operation, and when it is opened by energization, the back chamber (74) of the on-off valve (72) is communicated with the suction side, so the on-off valve (72) is opened by the spring (
76) and the intermediate pressure of the intermediate pressure port (1g) and retreat, and the intermediate pressure port (1g) is communicated with the suction port (1.) via the bypass passage (71), The compressor (1) has an intermediate pressure port (1) in the compression process.
g) Small-capacity operation with subsequent partial compression action, i.e.
It becomes unload operation.

Then, at the same time that the throat compressor (1) is switched to unload operation, the suction boat (1) of the compressor (1) is switched to the unload operation.
・), the high pressure liquid IF (81) communicates with it via the expansion mechanism (77) and the opened solenoid valve (20R11).
High-pressure liquid refrigerant is depressurized by the expansion mechanism (77) and compressed to 1
The exhaust gas is injected into the suction port of m(1) (1@), and the discharge gas is not overheated, and the cylinder block (not shown) and motor of compression-(1) are cooled and maintained at an appropriate temperature. be. Therefore, because the solenoid valve (20R8) is opened and the middle part of the compression process is communicated with the suction side of the compressor (1), the temperature of the discharged gas and the turbidity of the motor coil may rise excessively. It is possible to reliably prevent this from occurring, and the unloading operation can be tampered with without any hindrance.

According to the above configuration (K), one of the solenoid valves (2
011B) By simply controlling the opening/closing, the operation of the above-mentioned Hm structure on the side chain can be operated without using any complicated pipes or equipment, and liquid injection can be performed on the compression*(1) without malfunction during unloading operation. The compression hoe (1) can also be cooled, and refrigeration operation can always be carried out efficiently and reliably.

In Fig. 1, (90) opens when the high pressure increases;
A high pressure regulating valve (91) for regulating high pressure is connected in series with the capillary tube (90).
2) is a filter, (96) is a dryer, (94IL),
(94b), (95) are service shutoff valves, (96),
(97) is the reverse valve, (ν0) is the outdoor fan, and (n
pst) 4 as a safety device, (H
Pli is the high pressure switch for opening and opening the capacity during heating (%)
``F!l) is a low pressure switch for limiting capacity during cooling.

The i-chain side of the compressor (1) in the air conditioner Ict constructed as described above is operated as shown in the electric circuit of FIG. 2.

Namely, a number detector (100) that detects the number of operating indoor units (A), outputs an output below a predetermined number, and stops output exceeding a predetermined number, and a pressure detector (200) that detects the refrigerant pressure. ) to control the capacity, in other words, in the embodiment described above, the solenoid valve (20BB) is
When the number of operating indoor units (A) is less than or equal to a predetermined number, the unit opens or opens in response to a number signal from the number detector (100), and the number of operating indoor units (A) is equal to or less than a predetermined number. When the pressure exceeds the pressure, the pressure signal from the pressure detector (200) is used to open or open the valve.

The indoor units (A) to (D) shown in FIG.
), 6 indoor units (MU), (B), (0)
has a capacity of 1 horsepower, and the indoor unit (D) has a capacity of 6 horsepower, and this indoor unit (basket) is made by combining, for example, an indoor unit with a capacity of 1 horsepower and an indoor unit with a capacity of 2 horsepower in parallel. be.

In addition, the number detector (10 ports) is for each indoor unit)
(A) to (D) operation switch (R1!IA') I (
Connect indoor thermostats (2!1&), (23B), (230), (
Relay (23AI) #(
It consists of a changeover switch for 2311 (2311 # (230X) # (231
301 changeover switches are connected in parallel, and the fixed contact of the changeover switch in the relay C2'5DX)K is connected in series to the first changeover contact of each of these switches,
The first selector switch that is connected to the relay (23!IX)
the relay (X) is connected in series with the switching contact, - the normally open contact of this relay (l) is connected in parallel with the low pressure switch (LP11) constituting the pressure detector (200), and The solenoid valve (20R8) in the operation circuit Km is connected in series to this parallel circuit, and the solenoid valve (20R8) in the operation circuit Km is connected in series.
018).

In addition, in Fig. 2, (23A・ri is atte with relay, front E!
z) m (231) It is connected in series with the second switching contact of the changeover switch at $1, and one of the normally open contacts of this relay (23AY) is connected to the fan motor (MFO) of the outdoor fan (98). ) are connected in series.

In addition, (301 is an electromagnetic relay, the above-mentioned high pressure switch (HP 81) and compression 111. (1) superheat protector (
49c) to form a safety circuit, and when the electromagnetic relay (! During operation, the relay 23 is energized, and the relay 430H is a cooling/heating switching relay.
A relay (43oa*) *(
By neglecting to connect the normally open contact of 4goam) in series with the parallel circuit connected in parallel, this cooling/heating switching relay (43oz
) is installed on the input side of the control circuit 1 of the electric power 1゜Isofune (2Ql!l), and the cooling side switching contact of the changeover switch is connected to the normally open contact of the relay (X) and the A parallel circuit with the low pressure switch (LP8) is connected, and the high pressure switch (MP8 mushroom) is connected to the heating side switching contact.

Also (52 sim), (52νII), (52νC), (5
2νD) is the fan side contact (νA1) of each operation switch (18m) to (18D) of the indoor units l) to (D).
1l) of the indoor fan (νA) connected to the fan motor (
MFmu), (MFII)1(Mνo)* (MFD”)
*This is a relay that opens and opens (MνD).

Further, (52@) is a relay that performs the driving side of the motor (MO) in the compression l1k (1)K, and the relay (
520) is connected in series with the motor (MC). Also, (R-) is a relay, (Ro is a compression-(1)
This is the starting relay.

In the above configuration, when the electric circuit is connected to a power source, the electromagnetic relay (30x) is excited,
The normally closed contact closes, and when operating the operating switch (118^) of any one of the indoor units (A) to (1)) to perform cooling in this state, the cooling side contact and the fan When the side contacts close, the relay (2!
1 &
The switching contact switches to the second switching contact, and the relay (2
6 and closes its normally open contact.
1), the motor relay (52e) of the compressor (1) is energized via the closed circuit of its normally open contact to drive the motor (MO) of the compressor (1), and the outdoor The motor (MFO) of the fan (98) is driven, and the excitation of the relay (43011m) causes the cooling/heating switching relay (43011m) to close its normally open contact.
0HX) is energized, its changeover switch is switched to the cooling side contact, and the four-way selector valve (20B) is set to the cooling position. Furthermore, by energizing the relay (52 shims), the indoor unit) (1 )K drives the motor (M shim) of the indoor fan (ym).

With the above operation, the indoor unit (A) can be operated for cooling. However, when only one indoor unit (A) is operated, the electromagnetic relay (30x) is energized and the self-holding circuit due to this excitation is activated. Due to the formation of , the relay (X) becomes energized, the normally open contact of the relay (l closes, the control circuit 1 of the solenoid valve (20R1i) is closed, and the solenoid valve (2018) opens. As described above, the capacity side ms structure operates, and the compression (1) performs unloading operation.

In addition, when operating the operation switch (RIB) of another indoor unit (B) from the above state to operate this unit (B) together with the indoor unit (A), the relay (2311X) is energized. , the changeover switch switches from the first changeover contact to the second changeover contact, but the relay (l remains energized) and the pressure, compression - (1)
continues unloading operation.

Then, operate the operation switch (R8O) of yet another indoor unit (0) to turn the indoor unit (A), (B)
When operating three LC units, the above L'-(230X
) is energized, and the first changeover contact of the changeover switch becomes the second
Since the switching contact is switched, the relay (1) is demagnetized, its normally open contact opens, and the control circuit of the solenoid valve (201S) is opened, and the solenoid valve (2018) closes and the Compression m1(1) will perform load operation.

In this case, the solenoid valve (201B) is connected to the relay (I
) is connected in parallel with the normally open contact of the low-pressure pressure switch (L
PB), and when the load is small and the low pressure decreases, the low pressure switch (LPB) switches to the low temperature side contact, so the solenoid valve (20R1) is energized, and the solenoid valve (201! I) is opened, and the compression unit 11(1) is controlled to unload operation.The indoor unit (D) shown in FIG. (0) is larger than 2, so when operating this indoor unit (D), regardless of whether indoor units (M) to (0) are operating,
The relay (X) is demagnetized and the low pressure switch (
The system will be changed to one controlled by LPB) K.

In addition, when performing lI air conditioning, operation can be performed in the same way as when cooling, but during heating in Therefore, regardless of the operation of the relay (1), the opening and closing of the solenoid valve (20R1) is controlled by the operation of the high pressure switch (Hxs am).

In Fig. 2, (20AL) to (201DL) and (205G) to (20DG) are the source side branch pipes (8).
2) and a solenoid valve installed in the gas side branch pipe (84), each of these solenoid valves (20μL) to (20Da)
are connected in series with the changeover switches of the relays (23A to (2tDI)).

Further, (23DM) is a timer motor type defrost detector, (231 is a relay, (26) is a thermostat, and (23DMX) is an electromagnetic relay.

Further, (M) is a motor, (1) is a timer, and (C) is a clutch, and these parts form a timer motor, which cannot be started for, for example, 3 minutes after the compression 11 (1) stops operating. Also, (OH) is the crankcase heater, (
aS) is a starting capacitor, (R) is a resistance, (νυ1), (νυ) are fuses, (ss included)
e(”B), (580), (ssnt), (ssn goose)
is each motor (M F * ) P of the indoor fan (-)
- (My nm) series 1fiii node, (TMR-),
(Ding MR proverb) is a timer, (ri is a trance).

Further, in the embodiment shown in FIG. 2, when the indoor unit (D) is operating, the relay (X) is always demagnetized and the The solenoid valve (20R1) is switched from the number control to the pressure side -, but if the capacity of the indoor unit (D) is made equal to the capacity of the other indoor units (A) to (0), the indoor The changeover switch of the relay (23IIX) connected to the operation switch (R8D) of the unit (D) is the operation switch (R8M) to (i) of the indoor units (&) to (0).
tso)g Relay to be connected (23muX) ~ C2501)
It is connected in parallel with the selector switch.

Therefore, in this case, indoor units (A) to (1
)), if the number of operating relays (X
) for the capacity side, and in the case of 3 or 4 units,
The capacity side is controlled from the low pressure switch (LP8) K.

Furthermore, in the embodiment shown in FIG. 2, the solenoid valve (201
8) Connect the high pressure switch ()IP s嘗)''1?
As shown in Fig. 6, the relay (X
), and during heating, as well as during cooling, the solenoid valve (20
1B) Opening/closing control - may be made as if it were a compression control.
A type in which the compressor is returned to the suction side of the compressor via a bypass pipe with a capacity control structure and a closed valve, and a type in which the compression work is not performed on some cylinders of the membrane number Km. It goes without saying that the compressor may be a rotary type or a low-pressure dome type compressor that sucks in only a small amount of air.

As described above, the present invention provides one outdoor unit (0) Elf
In a multi-room air conditioner in which several indoor units (1 to (D)) are connected, a number detector (100) and a refrigerant pressure pressure detector (200) are provided to measure the pressure a1 (1). When the number of operating indoor units (M) to (D) is below a predetermined number, the capacity control 1ml structure is activated by the number detector (10).
When the number of indoor units (M) to (D) in operation exceeds a predetermined number, the load operation is controlled by the pressure signal from the pressure detector (200). - Since it was decided to perform unloading operation, there are problems with the conventional control method based only on refrigerant pressure using a pressure detector and the control method based only on the number of operating indoor units. It can solve all problems such as burnout, decrease in cooling (or heating) effect due to expansion of the operating range of unload operation, frost formation due to low pressure drop, and increase in compressor input, and ensure proper compression @ (1) at all times. It is possible to perform unloading and loading operations.

[Brief explanation of the drawing]

Fig. 1181 is a refrigerant piping system diagram showing an embodiment of the air conditioner of the present invention, Fig. w12 is an electric circuit diagram, and Fig. 3 is an electric circuit diagram of only the main parts showing another embodiment. (1) - Compressor (8) ... Refrigerant piping (16) - Indoor coil (1a) - Cylinder chamber (71) - Bypass passage (72) - On-off valve (74) - Back #1Jii! (75) - First control pipe (76) - Second control pipe (77) - Expansion mechanism (81) - High pressure liquid pipe (0) - Outdoor unit (MU), (B), (0 ), (D) - indoor unit (
201gg) - Electric 1 valve (X) - Relay (I, Pa)...Low pressure switch

Claims (1)

[Claims] (1) Pressure &! One outdoor unit with a(1) (0
), several indoor units (k) to (1)) each having an indoor coil (13) are connected to K, and the compression 11
In an air conditioner in which a capacity control mechanism is installed in k(1), the number of operating indoor units (MU) to (D) is detected, and output is performed when the number is below a predetermined number, and when the number exceeds the predetermined number. A number detector (100) for stopping the output and a pressure detector (200) for detecting the refrigerant pressure are provided, and the capacity control structure is set so that the number of operating indoor units (M) to (D) is a predetermined number. In the following cases, when the number of indoor units (M) to (D) in operation exceeds a predetermined number by controlling the number signal from the number detector (100), the number signal from the pressure detector (200) An air conditioner characterized by being controlled by a pressure signal. (2) The capacity control ma mechanism of the compressor (1) is
The middle part of the compression process in the cylinder chamber (1a) K and the pressure ! A bypass passage (7
1) and an on-off valve (7) that opens and closes the bypass passage (71).
2), the capacity control 1111 includes an operation circuit for operating the capacity control mechanism, and this operation circuit includes a solenoid valve (20BB ) The air conditioner according to claim 1, comprising: c'9 The operation circuit of the capacity-limited #air structure is connected to the high pressure side of the refrigerant pipe (8) connected to the compression am (1). It is equipped with a first control pipe (75) and a second control pipe (76) connected to the low pressure side, and the back chamber (74) of the on-off valve (72) that opens and closes the bypass passage (71) is connected to one solenoid valve. (205B,) selectively communicates 1ζ with one of the high pressure side and the low pressure side via each of the island control pipes (75) and (76), and
) to the low pressure side to open the on-off valve (72),
The low pressure side is connected to the refrigerant circuit (
8) The air conditioner according to claim 2, wherein the high pressure liquid pipe (81)K communicates with each other.