JPS6011786B2 - 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, the amount of refrigerant in this type of conventional multi-room air conditioning/heating system is set to the amount necessary for the capacity when multiple rooms are used. However, if a room is left unused, refrigerant will gradually accumulate 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. It happens. Therefore, in order to solve this problem, the refrigerant that accumulates in the pipes of the indoor unit that is inactive is sent to the pipes of the indoor unit that is in operation. This is not desirable as it flows into the pipes on the side of the indoor unit inside, and also has the following various drawbacks.

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

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 the gas pipe 18 and is branched into multiple paths from the branch pipe 11. The refrigerant passes through gas pipes 4 and 5 to the indoor units 2 and 3 through gas pipes 4 and 5.Then, the heat is condensed in the indoor heat exchangers 13 and 14, heating the room. The liquid is supplied to the indoor expansion valve 15, 1 used during cooling.
6, passes through check valves 17 and 18 arranged in parallel thereto, and returns to the outdoor unit 1 via liquid pipes 6 and T. 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 solenoid valve) 19, 20, and the milk skin tube 21
It then passes through the night watchman 22 and the liquid receiver 23, and expands under reduced pressure at the heating expansion valve 24, and then flows into the outdoor heat exchanger 25.
It evaporates endothermically. The cold soot is then sucked back into the compressor 8 from the accumulator 26 via the four-way valve 9. Reference numerals 27 and 28 indicate a high-pressure control valve and a conduit during heating overload operation, and 29 indicates a check valve provided so that the heating medium bypasses the heating expansion valve 24 during cooling.

Subsequently, in order to perform one-room heating operation, when the gas grate valve 3 and the liquid solenoid valve 20 are closed, the pipe on the indoor unit 3 side is closed, and only the indoor unit 2 is operated.

However, in this case, cold soot accumulates in the piping of the indoor unit 3 that is inactive, and the lining medium enters the piping due to leakage from the gas solenoid valve 13 and the liquid solenoid valve umbrella 0. There will be a shortage of ducts circulating through the pipes of the indoor unit 2, which will hinder operation. Therefore, the indoor unit 31 that is not in use can be connected to the suction side of the outdoor unit 1 via the series pipe line 32 and can be maintained at a low pressure, so that the above-mentioned residual and The invading cold butterflies are sent to the pipes on the indoor unit 2 side, avoiding any problems with single-room heating operation.However, "more cold butterflies than necessary circulate in the pipes on the indoor unit 2 side, which is not desirable. .And ~same as above~ check valve 33, capillary tube 34
A series pipe line 36 consisting of , indoor expansion valve 16, ]6, the operation of these expansion valves was unstable due to variations in the settings at the time of manufacture and changes over time.

As a result, when heating and cooling multiple rooms, imbalances tend to occur in the indoor unit power between the rooms, which is a major problem in multi-room heating and cooling systems. Sariko outdoor unit 1 is a compressor crab.
In addition to normal equipment such as the four-way valve 26 and the accumulator 26, there are gas solenoid valves 12, 3 liquid solenoid valves 99 28, which vary depending on the number of indoor units 293,
Since the serial conduits 32, 35, etc. are required, it is inconvenient that the outdoor units cannot be used in common.

Furthermore, when providing multiple anaerobic flow paths in the internal and external heat exchangers 13, 149, 25, ``even if a distributor is provided, it is easy to cause an imbalance in the distribution of cooling fluids, making it impossible to fully utilize the entire heat exchanger.'' It also had some problems.

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

In other words, &0 is an outdoor unit, and Toshitomi, 42 is an indoor unit.These two are connected by a pair of cold soot pipes.Then, the dust discharged from the compressor 43 during room heating operation is connected to the pipe. It passes through the 44t square solenoid valve 45 and the piping 46 in that order to reach the branch pipe 47.Then, since the solenoid valve &8 is closed and the indoor unit 42 is inactive, it passes through the related solenoid valve 49 and reaches the indoor heat exchanger. 58 and heat dissipation and condensation,
The room is heated. On the other hand, the condensed high-pressure cold soot liquid passes through the check valve 51, enters the outdoor unit through the solenoid valve 52 and branch pipe 53, is depressurized by the capillary tube 54, and is removed from the outside air by the outdoor heat exchanger 55. It absorbs heat and evaporates.Then, the refrigerated gas flowing out from the outdoor heat exchanger 55 passes through the pipe 56, the four-way solenoid valve & the pipe 5?, and is sucked into the compressor 43. When solenoid valves 8 and 5 are closed, cold soot may remain or gradually invade the pipe on the indoor unit 42 side, which is inactive. However, the indoor heat exchanger 6Q of the indoor unit Kame 2, which is inactive, is connected to the suction side of the compressor Tsuru 3 by the associated solenoid valve 9. Therefore, the solenoid valve 4 on the indoor unit 42 side
The cold pipe line from 8 to the solenoid valve 58 runs to the suction side of the compressor 43 and has a low pressure, so "cold soot flows into the compressor 43,
There will be no accumulation of cold soot in the cold soot pipe on the indoor unit 42 side that is inactive. Therefore, the indoor unit 41 which is in operation will not be affected by the lack of cooling chamber. However, since the amount of soot increases compared to when operating two-room heating, stable heating operation becomes impossible. In other words, when the indoor load (the number of operating indoor units) changes, it becomes impossible to operate at the optimal refrigerating charge amount corresponding to each indoor load. The above-mentioned solenoid valve 59
This is a solenoid valve that operates in the same way as the one on the indoor unit 41 side. The present invention is intended to solve the above-mentioned drawbacks of the conventional example, 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 cold soot pipe branch 65 that connects the two. The outdoor unit 62 consists of 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 installed in parallel, and these are connected as shown in the figure. do. In the outdoor heat exchanger 67, capillary tubes 72 are arranged in parallel corresponding to a plurality of cold soot channels (not shown) provided to reduce pressure loss due to piping and effectively utilize the heat exchanger. The heat exchanger works effectively by distributing the cold soot 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 that becomes low pressure during heating operation and high pressure during cooling operation, and a discharge port 7 that communicates with the discharge side of the compressor 66.
4, and an inlet 7 leading to the suction side of the outdoor heat exchanger 67
5 is provided. The indoor units 63 and 64 are of the normal capillary tube type, and are connected to indoor heat exchangers 76 and 77.
Indoor refrigerant gas pipes 78 and 79 led out from one end of this, and a capillary tube 80 led out from the other end,
81, and indoor liquid pipes 82, 83 connected to the end of this
It is composed of

Next, the cold soot piping branch 65 will be explained as follows.
85 is a branched cold soot gas pipe connected to the refrigerant gas pipe 84 at one end, which branches according to the number of indoor units 63 and 64, and is connected to the indoor medium gas pipe T8,
Connect directly to 79.

86 is a liquid pipe whose one end is connected to the inlet 75, and crab 7 is a branch liquid pipe whose one end is connected to the liquid pipe 86.
4, and are connected to indoor liquid pipes 82 and 83, respectively.

Reference numerals 88 and 89 indicate on-off valves such as reversible flow-type on-off solenoid valves provided in each branch liquid pipe 87 to control the refrigerant flow;
0 and 91 are the indoor units 63 and 6 from the on-off valves 88 and 89.
The first bypass line is one end connected to the branch liquid pipe 87 from the fourth side and connected to the low pressure pipe 92 whose pond end is connected to the low pressure connection port 73.
, 96, and capillary tubes 97, 98 are connected in series in this order.

These first bypass pipes 90 and 91 are partially installed in order to appropriately store the amount of cold soot in the pipes of the indoor units that are inactive (stopped) when the load is reduced in heating and cooling operation (reducing the number of operating indoor units). Bypass the refrigeration cycle so that the operation of the refrigeration cycle is not hindered when the load is reduced. 99 is low pressure pipe 92
The third bypass line is connected at one end to the refrigerant gas pipe 84 and at the other end to the refrigerant gas pipe 84 during cooling load reduction operation.
4, a check valve 100 and a capillary tube 101 are connected in series in this order.

The third bypass conduit 99 is set so that the capillary tubes 80 and 81 of the indoor units 63 and 64 can exhibit their proper capacity when operating in a single cooling room (load reduction) and when operating in two cooling rooms. This prevents the pipe line from becoming too constricted as a whole and the discharge temperature of the compressor 66 from increasing. For example, close the on-off valve 89 (at this time, the bypass solenoid valve 94
When the operation of the indoor unit 64 is stopped, a part of the refrigerated liquid flowing into the indoor unit 63 through the on-off valve 88 is transferred to the first bypass solenoid valve 93, which is opened in conjunction with the on-off valve 88. The third bypass pipe 9 flows into the bypass pipe 91 and flows into the medium gas pipe 84 which becomes low pressure during cooling.
9 and prevents the temperature of the compressor 66 from rising. 10
2 is a bypass pipe which is connected to the liquid pipe 86 at one end and to the refrigerant gas pipe 84 at the other end, and is opened and closed when the heating load decreases;
Bypass solenoid valve 103, capillary tube 104, and check valve 105 are connected in series toward liquid pipe 86 in this order.

Since the bypass solenoid valve 103 is open when the heating load is decreasing, such as when the indoor unit 64 is stopped operating, the second bypass pipe line 102 transfers a part of the refrigerant gas to the liquid pipe 86. Divert the flow to lower the high pressure. A check valve 106 is provided in the low pressure pipe 92 from the low pressure connection port 73, and prevents the refrigerant from flowing back into the refrigerant gas pipe 84 through the third bypass pipe line 99 during cooling operation.

In the above embodiment, two-room heating operation will be explained. The medium gas discharged from the compressor 66 passes through the four-way valve 68 → cold soot gas pipe 84 → branch refrigerant gas pipe 85 to each indoor unit 6.
3 and 64, and is radiated and condensed by indoor heat exchangers 76 and 77, heating the two rooms.

Further, the refrigerant passes through the capillary tubes 80 and 81 → the on-off valves 88 and 89 → the branch liquid pipe 87 → the liquid pipe 86 → the heating capillary tube 70 → the capillary IJ tube 72, and enters the outdoor heat exchanger 67 where it absorbs heat and evaporates. Then, the refrigerant passes through the four-way valve 68 and the accumulator 69 and is sucked into the compressor 66 again. Next, the single room heating operation will be explained. First, the on-off valve 89 is closed and the operation of the indoor unit 64 is stopped.

Therefore, the indoor unit 63 with the on-off valve 88 open
Since only one person is in charge of the operation, the circulation path for the cooling chamber is the same as in the two-room heating operation described above. However, since the second bypass conduits 102 and 91 operate at this time, 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. As a result, the high pressure of the refrigerant gas increases excessively during operation, causing trouble in operation. However, a part of the cold soot gas flowing through the cold soot gas pipe 84 passes through the open bypass solenoid valve 103 - capillary tube 104 - check valve 105 and is directly diverted to the liquid pipe 86 . The above-mentioned excessively high pressure is reduced. In addition, the cold soot gas flowing through the soot gas pipe 84 passes through a branch refrigerant gas pipe 85 to
A portion also flows into the pipeline and is stored there.

Then, due to this storage, the above-mentioned excessively high pressure is lowered, and the problem of single-room heating operation is resolved. However, if the amount of stored cold soot increases unnecessarily, there will be a shortage of refrigerant gas in the soot circulation path on the indoor unit 63 side during operation, which may cause problems in operation.

That is, since the branch refrigerant gas pipe 85 connected to the indoor unit 64 is open without a valve or the like in the middle,
Due to the rise and fall of the indoor temperature (load fluctuations) of the indoor unit 64 while it is inactive, an excessive amount of unnecessary soot accumulates inside the indoor unit 64. However, the bypass solenoid valve 94 opens when it detects that the temperature has become lower than that, so that the refrigerant stored in the pipe line of the indoor unit 64 is transferred to the first bypass consisting of the bypass solenoid valve 94, check valve 96, and capillary tube 98. The soot flows through the pipe 91 to the low pressure pipe 92, passes through the four-way valve 68 and the accumulator 69, and is sucked into the compressor 66. Then, when the pressure in the cold soot circulation path rises to a predetermined pressure, the bypass solenoid valve 94 is closed again. By performing this kind of operation, an appropriate amount of cold soot is stored in the pipe of the indoor unit 64 that is not in use.Therefore, if there is a shortage of lining medium in the lining circulation path of the indoor unit 63 that is in operation, is resolved, and single-room heating operation can be performed stably. Note that the bypass solenoid valve 93 of the first bypass pipe line 90 is closed at this time, so cold soot is not bypassed. In the case of the indoor unit 63, the above-mentioned opening and closing operations of the bypass pipe and the on-off valve are reversed.Furthermore, due to the ruts in the first bypass pipe 90 or 91 and the bypass pipe 102, the liquid cooling Due to the relative decrease, at the same time as the high pressure drops, the low pressure on the suction side of the compressor 66 is also affected and decreases, causing frost to form on the outdoor heat exchanger 67 that acts as an evaporator, and causing the compressor to The suction side of the compressor becomes overheated, and the temperature on the discharge side also rises.However, since a part of the soot gas flows to the liquid pipe 86 side through the second bypass pipe line 102, the low pressure of the compressor increases, This prevents the above-mentioned frost formation and also lowers the discharge temperature.In general, in the case of the capillary tube method, it is extremely difficult to control the refrigeration cycle using only the hot gas bypass method. At the same time, the refrigeration cycle lacks stability during overload operation.

In other words, this proposal makes it possible to configure a stable heating operation cycle for one room (or a small number of rooms) even in a capillary tube type heat pump multi-room heating and cooling system by appropriately combining the bypass pipes and controlling their respective operations. ing. In this way, the present invention has a bypass pipe that stores refrigerant in the pipe of an indoor unit that is not in operation, and bypasses this stored cold soot to bring the cold soot circulation path of an indoor unit that is in operation to a normal predetermined pressure. Since it is a control system, it reduces 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 decreases, and also prevents a shortage of refrigerant in the refrigerator circulation path during operation. can also be resolved.

Therefore, even when the heating load is reduced by reducing the number of indoor units from a predetermined number, stable operation can be performed. In addition, one end of the above-mentioned bypass pipe is connected to the branch liquid pipe from the indoor unit through the on-off valve provided on the branch liquid pipe connected to each indoor unit, and the pond end is connected to the low pressure pipe leading to the suction side of the compressor. Since the cooling gas pipe can be directly connected to the indoor unit via the branched cold soot gas pipe, the pressure loss in the soot circulation path is reduced and the efficiency of the heating and cooling capacity can be increased.

Furthermore, a bypass pipe is connected between the soot gas pipe and the liquid pipe,
Since the cold soot gas is bypassed to the liquid pipe when the heating load is reduced by reducing the number of indoor unit operations, the above-mentioned excessively high pressure in the liner soot circulation path is reduced, and the high pressure is reduced due to the relative reduction in liquid cooled soot. It is also possible to increase the pressure on the low-pressure side, which falls under the influence of the decrease in .

Therefore, it is also possible to prevent fog from forming in the outdoor heat exchanger that acts as an evaporator due to a drop in low pressure. Furthermore, since the bypass pipe connected to the branch liquid pipe is connected at one end to a low-pressure pipe from the outdoor unit side, and the other end is connected to a refrigerant gas pipe, a liquid bypass pipe is provided during cooling load reduction operation. The refrigerant can be flowed to the soot gas pipe through the bypass pipe, and it is possible to prevent an increase in the discharge temperature of the compressor due to excessive throttling of the refrigerant circulation path when the cooling load is reduced.

[Brief explanation of the drawing]

FIG. 1 is a pipe diagram showing one embodiment of the heat pump type multi-room air conditioning system of the present invention, and FIGS. 2 and 3 are pipe schematic diagrams showing conventional examples, respectively. 6-2...Outdoor unit, 63,6 turtle...
・・Indoor unit, 84 ・・Inside gas pipe, 86 ・・・
Liquid pipe, 87... Branch liquid pipe, 88, 89... Open/close valve, 90, 91... Bypass pipe line, 99... Liquid bypass pipe line, Volume 02... Bypass pipe line . Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1 Consisting of an outdoor unit, a plurality of indoor units, and refrigerant gas pipes and liquid pipes that connect the two to form a refrigerant circulation path, and branch the refrigerant gas pipes and liquid pipes according to the number of indoor units. This branch liquid pipe is connected only to an on-off valve that controls the refrigerant flow according to the operation or stop of each indoor unit, and one end of this on-off valve is connected to the branch liquid pipe from the indoor unit side, and the other end is connected to the a first bypass pipe connected to a low-pressure pipe leading to the suction side of the compressor; and a second bypass pipe connected between the refrigerant gas pipe and the liquid pipe and through which the refrigerant flows to the liquid pipe when the heating load decreases. , a third bypass pipe line having one end connected to the low pressure pipe from the outdoor unit side of the bypass pipe line 1 and the other end connected to the refrigerant gas pipe, and for flowing the refrigerant to the refrigerant gas pipe when the cooling load is reduced. A heat pump type multi-room air conditioning system.