JPS6011785B2 - Heat pump type multi-room air conditioning system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat pump type air-conditioning device used for air-conditioning and heating multiple rooms, and is capable of exhibiting stable heating and cooling performance regardless of the number of rooms used.

Generally, in this type of conventional multi-room air conditioning/heating system, the amount of refrigerant is set to the amount necessary for the capacity when multiple rooms are used. However, if there is a room that is not used, cold soot gradually accumulates in the pipes of the indoor unit that is not in operation, and there may be a shortage of cold soot in the pipes of the indoor unit that is in operation, making it impossible to operate. happens. Therefore, in order to solve this problem, the cold butterflies that accumulate in the pipes of the indoor units that are inactive are sent to the pipes of the indoor units that are in operation. However, as a result, more refrigerant than necessary flows into the conduit on the indoor unit side during operation, which is undesirable and also leaves behind various drawbacks as described below.

That is, in FIG. 2, 1 is an outdoor unit, 2 and 3 are indoor units, and both are connected to a pair of gas pipes 4 and 5, respectively.
They are connected by liquid pipes 6 and 7.

Then, during the heating operation of the two rooms, the compressor 8 of the outdoor unit 1
The soot gas discharged from the four-way valve 9 passes through a gas pipe 10 and is branched into a plurality of paths through a branch pipe 11. The gas then passes through gas-side reversible flow solenoid valves (or solenoid valves with a built-in check valve) (hereinafter referred to as gas solenoid valves) 12 and 13, and is led to the indoor units 2 and 3 from gas pipes 4 and 5. Then, the left heat is condensed in the indoor heat exchangers 13 and 14 to heat the room. The cooling liquid is an indoor expansion valve 15, 1 used during cooling.
6, passes through check valves 17 and 18 arranged in parallel thereto, and returns to the room guard unit 1 via liquid pipes 6 and 7. In other words, for cold soot liquid, use a reversible flow solenoid valve (or a solenoid valve with a built-in check valve) on the liquid side.
(hereinafter referred to as liquid electromagnetic valve) 19 and 20, join at branch pipe 2, pass through liquid pipe 22, liquid receiver 23, and expand under reduced pressure at heating expansion valve 24, and then enter outdoor heat exchanger 25. It evaporates endothermically. The soot is then sucked back into the compressor 8 from the accumulator 26 via the four-way valve 9. 2
Reference numerals 7 and 28 indicate a high-pressure control valve and a conduit during heating overload operation, and reference numeral 29 indicates a check valve provided to allow butterflies to bypass the heating expansion valve 24 during cooling.

Subsequently, when the gas solenoid valve 13 and the liquid solenoid valve 20 are closed to perform one-room heating operation, the pipes of the three indoor units are closed, and only the indoor unit 2 is operated.

However, in this case, cold soot remains in the piping of the indoor unit 3 that is inactive, and leakage from the gas solenoid valve 13 and the liquid solenoid valve 20 causes soot to enter the piping. For this reason, there is a shortage of refrigerant circulating through the pipes of the indoor unit 2, which causes problems in operation. However, a series circuit 32 consisting of a check valve 30 and a capillary tube 31 is connected to the liquid pipe 7 and the heating expansion valve 24 on the side that becomes low pressure during heating. Therefore, the indoor unit 3 that is inactive is connected to the series pipe line 3.
2 can be connected to the suction side of the outdoor unit 1 and can be maintained at a low pressure, so the above-mentioned residual accumulation and intruding cold soot can be sent to the pipe on the indoor unit 2 side, avoiding trouble in single-room heating operation. . However, more cold soot than necessary circulates in the pipes on the indoor unit 2 side, which is not desirable. and,
As before, a direct pipe line 35 consisting of a check valve 33 and a capillary tube 34 is connected to the indoor unit 2.
When the indoor unit 2 is stopped, it operates in the same manner as described above. In addition, since the heating expansion valve 24 and the indoor expansion valves 15 and 16 are used to control the flow rate of the refrigerant, their operation may become unstable due to variations in the settings of these expansion valves during manufacture, aging, or clogging. There wasn't.

As a result, when multiple rooms are air-conditioned, an imbalance tends to occur in the indoor unit capacities of each room, which is a major problem in multi-room air-conditioning systems. In addition, the outdoor unit] is a compressor 8,
In addition to normal equipment such as the four-way valve 9, outdoor heat exchanger 25, and accumulator 26, there are gas solenoid valves 12, 13, liquid solenoid valves 19, 20, series circuits 32, 35, etc. that vary depending on the number of indoor units 2, 3. This was inconvenient because the outdoor unit could not be used commonly.

Furthermore, ``Even if a distributor is provided when providing multiple cold soot flow paths in the internal and external heat exchangers 13, 14, and 25, it is easy to cause an imbalance in the distribution of the refrigerant, making it impossible to fully utilize the entire heat exchanger.'' It also had some problems.

FIG. 3 shows another conventional embodiment, and this structure also has various problems.

That is, 401 is an outdoor unit, 41 and 42 are indoor units, and both are connected by a pair of cooling pipes. The cold soot discharged from the compressor 43 during the room heating operation passes through the pipe 44, the four-way valve 45, and the pipe 46 in this order, and reaches the branch pipe 47. Since the solenoid valve 48 is closed and the indoor unit 42 is inactive, the heat is radiated and condensed through the open solenoid valve 49 and into the indoor heat exchanger 501, heating the room. On the other hand, the condensed high-pressure refrigerating liquid is removed by the check valve 51.
The air then enters the outdoor unit 40' through a solenoid valve 52 and a branch pipe 53, is depressurized by a capillary tube 54, and is evaporated by absorbing heat from the outside air through an outdoor heat exchanger 55. The cold soot gas flowing out from this outdoor heat exchanger 55 passes through a pipe 56, a four-way solenoid valve 45, and a pipe 57 to the compressor 4.
3 is inhaled. In this way, during single-room heating operation, the solenoid valves 48 and 58 are closed and cold soot remains or gradually enters the pipe line on the side of the indoor unit 42, which is inactive.
The amount of cold soot circulating on the indoor unit 41 side during operation becomes insufficient, causing problems in operation.

However, the indoor heat exchanger 60 of the indoor unit 42 that is inactive is connected to the suction side of the compressor 43 due to the solenoid valve 59 that is open. Therefore, the refrigerant pipe line from the solenoid valve 48 to the solenoid valve 58 on the indoor unit 42 side passes through the suction side of the compressor 43 and becomes low pressure, so the refrigerant flows into the compressor 43 and the indoor unit 42 is in rest. Cold soot will no longer accumulate in the cold soot pipe on the side. Therefore, the indoor unit 41 during operation will not be affected by the lack of cold wires. However, since the amount of cold soot is greater than during two-room heating operation, stable heating operation cannot be achieved. That is, when the indoor load (the number of indoor units in operation) changes, it becomes impossible to operate with a uniform cold soot filling amount corresponding to each indoor load, and it is impossible to operate in a well-balanced state. Note that 61 is a solenoid valve that functions in the same way as the solenoid valve 59 described above, and is located on the indoor unit 41 side. The present invention is intended to solve the drawbacks of the conventional examples mentioned above, and one embodiment thereof will be described below with reference to FIG.

The multi-room air conditioning system of the present invention includes an outdoor unit 62, a plurality of indoor units 63, 64, and a refrigerant pipe branch 65 that connects the two. The outdoor unit 62 is constructed by connecting a compressor 66, an outdoor heat exchanger 67, a four-way valve 68, an accumulator 69, a heating capillary tube 70, and a check valve 71 arranged in parallel thereto as shown in the figure. In the outdoor heat exchanger 67, capillary tubes 72 are arranged in parallel corresponding to a plurality of cold soot flow paths (not shown) provided in order to reduce pressure loss due to piping and effectively utilize the heat exchanger. The heat exchanger works effectively by distributing the refrigerant evenly. Furthermore, the outdoor unit 62 has a low pressure connection port 73 connected between the outdoor heat exchanger 67 and the four-way valve 68, which becomes low pressure during heating operation and high pressure during Z cooling operation.
, a discharge port 74 communicating with the discharge side of the compressor 66, and an inlet port 75 communicating with the suction side of the outdoor heat exchanger 67. The indoor units 63 and 64 are of the normal capillary tube type, and include indoor heat exchangers 76 and 77, indoor cold soot gas pipes 78 and 79 led out from one end of these, and capillary tubes 80 and 81 led out from the same end of the pond. , and indoor liquid pipes 82 and 83 connected to the tip thereof.

Next, the refrigerant pipe branch 65 will be explained.
is a refrigerant gas pipe connected to the discharge port 74, and 85 is a branch cold soot gas pipe whose one end is connected to the liner gas pipe 84, which branches according to the number of indoor units 63, 64, and is connected to the indoor cold soot gas pipe 78,
Connected to 79. 86' is a liquid pipe whose one end is connected to the inlet 75, and 87 is a branch liquid pipe whose one end is connected to the liquid pipe 86, which branches according to the number of indoor units 63, 64, and connects to the indoor liquid pipes 82, 83, respectively. Connecting.

Reference numerals 88 and 89 are provided in the branch refrigerant gas pipes 85 and 85, respectively, and on-off valves are reversible flow type on-off solenoid valves for controlling the flow of cold soot, and 90 and 91 are provided in the branch liquid pipes 87 and 87, respectively.
An on-off valve consisting of a reversible flow-type on-off solenoid valve that controls the cooling flow. 92 is a bypass solenoid valve that opens when air conditioning/heating a single room.
When operating a single cooling room, capillary tube 93 and check valve 9
4, it is connected between a liquid pipe 86 that becomes high-pressure during cooling and a refrigerant gas pipe 84 through which a low-pressure gas cooling butterfly passes.

In order to prevent the capillary tubes 80 and 81, which are properly set during two-room cooling operation, from becoming too constricted as a whole system during single-room operation due to their characteristics, the discharge temperature of the compressor 66 increases. , constitutes a third bypass pipe 95 that bypasses the bridge pressure cold soot liquid to the cold soot gas pipe 84. In addition, the bypass solenoid valve 92 is connected between the liquid pipe 86 and the low pressure pipe 98 connected to the low pressure connection port 73 via the capillary IJ tube 96 and the check valve 97 during single room heating operation. A third bypass conduit 99 is configured at the time. The liquid-cooled soot is then bypassed to the low-pressure pipe 98. 1001 is also a bypass solenoid valve when operating a single heating room, and is connected between the liquid pipe 86 and the refrigerating gas pipe 84 via the capillary tube 101 and the check valve 102, and bypasses the refrigerant gas to the liquid pipe 86. A second bypass conduit 103 is configured during single room heating operation.

104 is a pressure control valve that opens and closes continuously as the high pressure of the refrigerant gas increases during single-room heating operation; one end is connected to the refrigerant gas pipe 84, and the other branched end is a check valve 105;
It is connected to branch refrigerant gas pipes 85, 85 via 106.

Then, the pressure control valve 104 bypasses the on-off valve 88 or 89 in either one of the indoor units 63 or 64 that is out of operation to store soot gas, and adjusts the pressure to reduce the high pressure during single room heating operation. A conduit 107 is configured. Reference numeral 108 is a first bypass pipe which functions as a pressure adjustment pipe 107 and controls the outflow amount of the medium stored in the indoor unit 63 or 64 when the operation is suspended.
The low pressure pipe 98 is
to bypass the cold soot liquid to the low pressure pipe 98.

In the above-mentioned embodiment, to explain the two-room heating operation, the cold soot gas discharged from the compressor 66 is transferred to the four-way valve 68 → the cold soot gas pipe 84 → the on-off valves 88, 89 → the branch soot gas pipe 85,
The heat is guided to each indoor unit 63764 via the indoor heat exchangers 76 and 77, where it is radiated and condensed to heat the two rooms.

Furthermore, the medium liquid flows out from the indoor units 63 and 64 and flows through the branch liquid pipes 87 and 87 → the on-off valves 90 and 91 → the liquid pipe 86 → the heating cavity tube 70 → the capillary tube 72, and is transferred to the outdoor heat exchanger. 67 and evaporates endothermically. The refrigerant then passes through the four-way valve 68 and the accumulator 69 and returns to the compressor 66 again. Next, I will explain about single room heating operation.
First, the on-off valves 89 and 91 on the gas side and the liquid side are closed, and the operation of the indoor unit 64 is stopped.

Therefore, only the indoor unit 63 whose on-off valves 88 and 90 are open operates, and the refrigerant circulation path at this time is the same as one path during the two-room heating operation described above. However, during this heating operation, each bypass pipe 9
9, 103, 108 and the pressure adjustment pipe 107 operate, so their effects will be described in detail.

In this device, the capacity of the heat exchanger and the degree of restriction of the capillary tube are set appropriately for two-room heating operation.

On the other hand, during single-room heating operation, the capacities of the indoor heat exchangers 76 and 77, which function as condensers, are relatively reduced. Then, during operation, the high pressure of the refrigerant gas increases excessively, causing problems in operation. However, the cold soot gas pipe 8
A portion of the refrigerant gas flowing through the bypass solenoid valve 10 is opened.
0, the capillary tube 101 and the check valve 102 are controlled to divert the liquid to the liquid pipe 86 and join the liquid cooled soot flowing through the liquid pipe 86, so that the above-mentioned excessively high pressure is
is lowered by the bypass line 103.

Further, a part of the cold soot gas flowing through the medium gas pipe 84 passes through the pressure adjustment pipe 107 and is stored in the pipe of the indoor unit 64 that is inactive. That is, the pressure control valve 1 opened at high pressure
04, the refrigerant gas that has flowed into the branch cold soot gas pipe 85 via the check valve 106 is isolated from the cold soot circulation path by the on-off valves 89 and 91, so that the refrigerant gas is not cooled indoors. Missing gas pipe 79, indoor heat exchanger 77, capillary tube
The liquid is stored in the tube 81, the indoor liquid pipe 83, and the branch liquid pipe 87, causing a pressure drop. At this time, the soot gas pressure passing through the on-off valve 88 is higher than that in the pressure adjustment pipe 107, so it does not flow into the refrigerant circulation path of the indoor unit 63 in operation via the check valve 105. In this way, the soot gas is stored in the pipe line of the indoor unit 64 which is not in operation, and the high pressure can be reduced.

However, if the amount of stored cold soot becomes unnecessarily large, there is a risk that the operation will be hindered due to a shortage of cold soot gas in the cold soot circulation path on the indoor unit 63 side during operation. However, "the check valve 109 leading to the indoor unit 64 which is out of operation, the first bypass pipe 108 from the capillary tube 111 to the low pressure pipe 98, the capillary tube in which the above-mentioned stored medium has been sufficiently squeezed" 111 and returns to the suction side of the compressor 66.
Therefore, the pressure control valve 104, the capillary tube 1
11, the indoor unit 6 which is out of operation has an appropriate amount of cold soot.
By storing the liquid in the pipe line 4, it is possible to eliminate operational problems in the refrigeration cycle caused by excessive liquid accumulation or small liquid accumulation. Furthermore, when the high pressure is reduced by the relative reduction of liquid-cooled soot, the low pressure on the suction side of the compressor 66 is also affected and reduced ~ the outdoor heat that acts as an evaporator. Frost may form on the exchanger 67 or the suction side of the compressor 66 may overheat.
The temperature on the discharge side also increases.

However, the liquid cooled soot flows down the third bypass pipe 99 and the liquid pipe 8
6, the refrigerant gas bypasses to the low pressure pipe 98, and also passes through the second bypass pipe line 103 to the liquid pipe 86.

Therefore, the low-pressure pressure is increased, and the outdoor heat exchanger 67 is prevented from being stale, and the discharge temperature is also lowered.In addition, in the case of the capillary tube method, only the hot gas bypass method is used to cool down the refrigeration. When implementing cycle control, it is clear that the coefficient of performance (ratio of equipment input and capacity) will drop significantly and at the same time the stability of the refrigeration cycle will be lacking during overload operation. By controlling the operation in combination with the above, it becomes possible to configure a stable heating operation cycle for one room (or a small number of rooms) in a capillary tube type heat pump multi-room heating and cooling system.Furthermore, in the above embodiment, four It has been explained that the above bypass pipes are used together, but it is clear that the above pipes may be selected depending on the capacity ratio of the indoor units and the number of connected units.

Furthermore, it is clear that the pressure control valve 104 is not necessarily set to operate all the time during single-room heating operation, but may have a configuration in which it operates only when an overload occurs during single-room heating operation, for example, to achieve the same effect. In this way, the present invention provides a branch refrigerant gas pipe that connects a plurality of indoor units to an outdoor unit to form a refrigerant circulation path;
In addition to providing an on-off valve in the liquid pipe and the M skin liquid pipe, a pressure adjustment pipe is connected in parallel to this on-off valve on the gas side, and a branch liquid pipe is connected to the on-off valve on the liquid side on the indoor unit side from this on-off valve. The first bypass line is connected at one end and connected to the low-pressure pipe during heating operation at the other end, so cold soot is stored in the line of the indoor unit when the unit is out of operation, while a portion of it is bypassed. The cold soot circulation path of the indoor unit can be maintained normally during operation.

Therefore, it is possible to reduce the excessively high pressure in the cold soot circulation path that occurs due to a relative decrease in the capacity of the indoor heat exchanger when the heating load is reduced, and also to eliminate refrigerant shortages during operation. It is possible to perform stable operation even when the heating load is reduced.Also, there is a second pipe between the refrigerant gas pipe and the liquid pipe that opens when the heating load is reduced.
By connecting the second bypass pipe and bypassing the refrigerant gas to the liquid pipe, the second bypass pipe and pressure adjustment pipe ensure that excessively high pressure is reduced, reducing the heating load. It is possible to further stabilize the operation at the time.

Furthermore, there is a third bypass line that opens when the cooling/heating load decreases, with one end connected to the liquid pipe and the other end connected to the refrigerating gas pipe and the low-pressure pipe. Bypassing cold soot to each
When the heating load decreases, it is also possible to lower the excessively high pressure and increase the pressure on the low pressure side, which is affected by the relative decrease in liquid refrigerant.

Therefore, frost formation on the outdoor heat exchanger can be prevented, and operation can be stabilized when the heating load is reduced.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of pipes showing an embodiment of the heat pump type multi-room air conditioning system of the present invention, Fig. 2 is a schematic diagram of pipes showing a conventional example, respectively. ...Indoor unit, 84M...Refrigerant gas pipe, 85...Branch soot gas pipe, 86...Liquid pipe, 87...Branch liquid pipe, 88
,89;98ri91...Opening/closing valve,9fu 99,Kan03,
Tortoise 08...To the bypass pipe line Q7...Pressure adjustment pipe line. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1 Consists of an outdoor unit, a plurality of indoor units, and refrigerant gas pipes and liquid pipes that connect the above two to form a refrigerant circulation path, and branch off from the refrigerant gas pipes and liquid pipes according to the number of indoor units. and an on-off valve provided on the branched refrigerant gas pipe and the branched liquid pipe, and a pressure regulating pipe line provided in parallel with the on-off valve so as to bypass the on-off valve on the gas side.
A first bypass pipe line is connected to one end of the branch liquid pipe from the indoor unit from the liquid side on-off valve, and the other end is connected to the low pressure pipe leading to the suction side of the compressor during heating operation, and one end is connected to the refrigerant gas pipe. a second bypass pipe line, the other end of which is connected to the liquid pipe, and the second bypass pipe line through which the refrigerant flows when the heating load decreases;
A heat pump type multi-room air-conditioning/heating system equipped with a third bypass pipe whose other ends are connected to the refrigerant gas pipe and the low-pressure pipe, respectively, and which allows the refrigerant to flow to the refrigerant gas pipe when the cooling load decreases and to the low-pressure pipe when the heating load decreases. .