JPS5919255Y2 - air conditioner - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an air conditioner with a new structure that allows easy operation of cooling and dehumidification using a simple refrigeration circuit.

A conventional air conditioner that can perform cooling and dehumidification operations separately uses a condenser A as shown in the circuit shown in FIG.

A cooling capillary tube C with a bypass circuit is provided between the evaporator and reheater 8, and an evaporator and reheater B,
It has a configuration in which a capillary tube E for dehumidification with a bypass circuit is installed between the evaporator. During cooling operation, solenoid valve F is closed and solenoid valve G is opened, while during dehumidification operation, solenoid valve F is closed. It was designed to open and close solenoid valve G.

Such a circuit configuration has the disadvantage that it has many components and the circuit becomes complicated, leading to a rise in device cost.

In addition to the above structure, a refrigerant circuit using one three-way solenoid valve I in the indoor unit as shown in FIG. When switching between high and low pressures, the indoor heat exchanger B', which functions as an evaporator and reheater, generates a refrigerant shock sound, which is undesirable as it gives a user a feeling of discomfort.

In view of the current situation in which conventional air conditioners of this type have various deficiencies, the present invention was developed in an attempt to eliminate these deficiencies.

The specific contents of the present invention will be explained in detail below with reference to the accompanying drawings.

In FIG. 1, the left half divided by a dashed line is an outdoor unit, and the right half is an indoor unit.

A compressor 1 is installed in the outdoor unit. Outdoor coil 2. Outdoor fan 12. Liquid receiver 7 and solenoid valve 11. A refrigerant amount adjusting device 9 having a capillary tube 10 and an accumulator 8 as constituent elements is provided respectively, and the indoor unit has a first indoor coil 3. Capillary tube for both cooling and dehumidification 4. A second indoor coil 5 and an indoor fan 6 are each provided to act as an evaporator.

An outdoor coil 2. is provided between the discharge side and the suction side of the compressor 1. Receiver7. 1st indoor coil 3. Capillary tube 4. 2nd indoor coil5. These are connected in series in the order of the accumulator 8, and the liquid receiver 7 and the first
A bypass pipe in which the solenoid valve 11 of the refrigerant amount adjustment device 9 and the capillary tube 10 are interposed between the high-pressure pipe between the indoor coil 3 and the low-pressure pipe between the second indoor coil 5 and the accumulator 8. 15 to form a refrigerant circuit.

Therefore, when the solenoid valve 11 of the refrigerant amount adjustment device 9 is closed, the total amount of refrigerant flowing out from the outdoor coil 2 is reduced to the first level.
It flows into the indoor coil 3.

On the other hand, when the solenoid valve 11 is opened, the refrigerant flowing out from the outdoor coil 2 is transferred to the first indoor coil 3 and the bypass pipe 1.
The refrigerant that flows into the bypass pipe 15 is depressurized in the capillary tube 10, and then flows into the accumulator 8, where it is separated into gas and liquid.The gas refrigerant is sucked into the compressor 1, and becomes liquid refrigerant. is stored in the accumulator 8.

Therefore, as soon as the electromagnetic valve 11 is opened, a predetermined amount of liquid refrigerant is stored in the accurator 8.

Note that the refrigerant amount adjusting device 9 is provided to bridge between the high and low pressure pipes of the refrigerant circuit, but the device 9 stores a predetermined amount of refrigerant in order to adjust the amount of circulating refrigerant in the refrigerant circuit. The location and structure of the refrigerant are not limited to those of the above embodiments, as long as the refrigerant has the function of releasing the refrigerant into the refrigerant circuit.

Also, the specific structure of the indoor unit is shown in Figure 2.
FIG. 2 is a sectional view of the indoor unit, with the left side of the box-shaped casing 17 shown in FIG. A second indoor coil 5 is disposed inward in a backwardly inclined manner with the upper side inclined backward, and further below the second indoor coil 5 is an air outlet 1.
A cross flow fan 6 is disposed as an indoor fan in a casing 17 up to 9.

The first indoor coil 3 is placed in the upper part of the casing 17 in front of the second indoor coil 5 and close to the upper corner of the front surface of the second indoor coil 5, that is, the second indoor coil 5
It is arranged at a position on the upstream side with respect to the second heat exchange tube section 5b described later.

These first and second indoor coils 3 and 5 are arranged in the air flow path upstream of the indoor fan 6 within the casing 17, and the refrigerant flow path is as shown in FIG.
The refrigerant flowing out of the outdoor coil 2 flows through the first indoor coil 3, passes through the capillary tube 4, and is transferred to the first heat exchange tube group 5a, the second heat exchange tube group 5b, and the remaining heat exchangers of the second indoor coil 5. A specific distribution form is adopted in which the water is passed through the tube group 5c and the outlet heat exchange pipe 5d in sequence, and then flows to the accumulator 8 of the outdoor unit.

The second indoor coil 5 is composed of a cross-fin coil heat exchanger equipped with heat exchange tubes P arranged in a staggered manner in two rows and multiple stages, and has a larger heat exchange area than the first indoor coil 3. Make it quite large.

For example, if the heat exchange area of the second indoor coil 5 is 1,
The first indoor coil 3 is about 0.125 degrees, and
The outdoor coil 2 is set to approximately 1.3.

Although the first indoor coil 3 may be a cross-fin coil like the second indoor coil 5, it is possible to use a heat exchanger with oblique fins around the heat exchange tube as shown in FIG. The first indoor coil 3 can be made smaller, and therefore the casing 1
The space in front of the second indoor coil 5 within the casing 17 can be reduced, and the depth of the casing 17 can be reduced.

Therefore, in the second indoor coil 5, the first heat exchange tube group 5a is an assembly of heat exchange tubes P that are located on the lower stage side of the approximately center of the heat exchange tubes P in the stage direction, and each heat exchange tube group 5a is Pipe P
are connected as shown in the second figure, and the outlet side heat exchange pipe 5d is connected to the first
A heat exchange tube P existing directly above the heat exchange tube group 5a, and a second
The heat exchange group 5b is an assembly of a plurality of heat exchange tubes P existing in the front row above the outlet side heat exchange tube 5d and the uppermost heat exchange tube P among the heat exchange tubes P in the rear row, and , 5
C is an assembly of heat exchange tubes P other than the heat exchange tube groups 5a, 5b and the outlet side heat exchange tube 5d.

The operation mode of the air conditioner having the above configuration will be explained next.

During cooling operation, the solenoid valve 11 is closed and the refrigerant amount adjustment device 9 is inactivated.

In the refrigeration cycle system, a predetermined amount of refrigerant circulates, and almost all of the high-pressure gas refrigerant is condensed and liquefied in the outdoor coil 2, and then in the first
After being supercooled by a part of the indoor circulating air in the indoor coil 3, the pressure is reduced in the capillary tube 4, and the air is evaporated in the second indoor coil 5, and then passes through the accumulator 8 to the compressor 1. The refrigerant immediately before is completely liquefied and is in a supercooled state, and this state is called a liquid seal.

In this cooling operation, a part of the indoor circulating air is heated by the first indoor coil 3 which acts as a supercooler, but since the temperature of the refrigerant flowing through the first indoor coil 3 has decreased considerably, The temperature difference with the suction air temperature is small;
Moreover, since the heat exchange area of the first indoor coil 3 is also quite small, the amount of heating is small.

Moreover, this heating of the indoor circulating air is substantially offset by the increase in the cooling capacity of the second indoor coil 5, so that the cooling capacity hardly decreases.

That is, the temperature of the indoor circulating air on the population side of the second indoor coil 5 rises from temperature t1 to t2 due to heating in the first indoor coil 3, and the temperature of the refrigerant evaporation in the second indoor coil 5 and the circulating air temperature increase. As the temperature difference increases, the subcooling of the refrigerant at the outlet of the first indoor coil 3 increases, and the proportion of liquid in the refrigerant flowing into the second indoor coil 5 increases, so that the cooling of the second indoor coil 5 increases. Capacity increases.

This increase is approximately equal to the increase in cooling capacity that is required as the indoor circulating air temperature on the population side of the second indoor coil 5 rises, and it is as if the cooling capacity of the first indoor coil 3 is indirectly increased through the circulating air. A state is created in which heat is exchanged between the refrigerant and the refrigerant in the second indoor coil 5, and the amount of heating in the first indoor coil 3 for the indoor circulating air is equal to that in the second indoor coil 5.
This is offset by the increase in the cooling capacity of the indoor coil 5, so that the cooling capacity hardly decreases.

During this cooling operation, warm indoor air that flows in from the suction port 18 is heated by the first indoor coil 3, and a part of this inflow indoor air is heated via the top wall surface of the casing 17, but the second indoor coil Among the heat exchange pipes 5, if the heat exchange pipe located behind the first indoor coil 3 is in the overheated area, the air passing through this part will hardly be cooled and will not be dehumidified until the indoor fan 6, and here the second
When the rotor comes into contact with the fan rotor cooled by the low-temperature air that has passed through the lower half of the indoor coil 5, the contained moisture condenses on the blades of the rotor, and this dew is blown off to the air outlet. There is a risk that it will scatter from 19 into the room.

However, in the air conditioner according to the present invention, the second heat exchange tube group 5b located immediately behind the first indoor coil 3 and close to the casing 17 in the second indoor coil 5 is a portion through which low-pressure refrigerant liquid flows. Therefore, the above-mentioned warm air is cooled and dehumidified when passing through the second heat exchange tube group 5b, so that the moisture content of the air reaching the indoor fan 6 is The temperature is decreasing,
Therefore, even if it comes into contact with the cooled fan rotor, there is no condensation at all, and thus water droplets flying out from the air outlet 19 are reliably prevented.

On the other hand, during dehumidification operation, the solenoid valve 11 is opened and the refrigerant amount adjustment device 9 is operated.

In this case, the outdoor fan 12 is switched to low speed to reduce the air volume.

Part of the liquid refrigerant in the high pressure line is capillary tube 10
The amount of refrigerant stored in the accumulator 8 gradually increases.

Thus, the state of the refrigerant immediately before the capillary tube 4 becomes a flash state, the flow resistance value of the refrigerant in the capillary tube 4 increases significantly, and the amount of refrigerant flowing through the first and second indoor coils 3 and 5 decreases.

As a result, there is a so-called gas starvation operation, where the low pressure decreases and the high pressure tends to decrease as well.

However, since the outdoor fan 12 has a low air volume, the high pressure does not drop and remains constant, and the reduced capacity of the outdoor coil 2 is secured as the heating capacity of the first indoor coil 3.

Note that the liquid-gas mixing ratio immediately before the capillary tube 4 can be determined at the design stage so that the capacities of the first indoor coil 3 and the second indoor coil 5 are approximately matched.

In this way, the refrigerant flow rate of the second indoor coil 5 becomes small, and the effective evaporation area of the coil 5 gradually decreases from the downstream side, and the outlet side heat exchange tubes 5d, each heat exchange tube 5C, and the second heat exchange tube group 5b The area becomes an overheating region, and the indoor air is heated by the first indoor coil 3 to become high-temperature air and reach the indoor fan 6.

On the other hand, only the first heat exchange tube group 5a of the second indoor coil 5 acts as an evaporator, and therefore the cooling capacity of the first indoor coil 3 is reduced to approximately half or less. It can be said that the state is almost in balance with the heating capacity.

After the air that has been cooled and dehumidified while passing through the first heat exchange tube group 5a and the air that has been heated and has a relatively high temperature while passing through the first indoor coil 3 are mixed by the indoor fan 6. , dry air with little sensible heat change is sent into the room, effectively dehumidifying it.

In this case, the cooling capacity of the first heat exchange tube group 5a is considerably smaller than that during cooling;
Since the indoor air passing through the indoor coil 3 is heated to a high temperature, problems such as dew condensation due to air merging at the indoor fan 6 do not occur as in the case of cooling.

Note that reducing the air blowing capacity of the outdoor fan 12 in the above dehumidifying operation is extremely suitable for preventing loss of dehumidifying function due to a decrease in circulation volume due to a high pressure drop. Cooling and dehumidification operations are fully possible without adjusting the air volume.

On the other hand, the refrigerant amount adjusting device 9 may be one illustrated in FIGS. 3 to 6, in addition to the device shown in FIG. 1.

The device shown in FIGS. 3 and 4 is a part 2 of an outdoor coil 2.
A is used as a liquid reservoir during dehumidification, and the fifth
What is shown in the figure is a solenoid valve 16 in the bypass circuit for dehumidification time and cooling time, a liquid receiver 13 for storing liquid during dehumidification,
A capillary tube 14 is provided which is used as a passage for releasing the liquid reservoir during cooling.

In contrast to each of the above devices in which the refrigerant amount adjusting device 9 is provided on the outdoor unit side, the device shown in FIG. It was used as a reservoir.

It is necessary that each of the above-mentioned parts is a sufficient device to achieve the intended purpose of the present invention.

As is clear from the above detailed description, according to the present invention, the first indoor coil 3 and the second indoor coil 5 are connected in series through the capillary tube 4 without changing the refrigerant amount adjustment device. Switching between cooling operation and dehumidification operation can be performed simply by switching between activation and deactivation of step 9, which eliminates the need to use two capillary tubes or install a control valve such as a three-way solenoid valve in the circuit. Compared to harmonic machines, the circuit configuration is extremely simplified and the effect of reducing equipment costs is significant.

Moreover, even though it is a simple circuit, cooling and dehumidifying operation can be performed, eliminating the need for a dehumidifying pressure reducer, three-way switching valve, or other control valves.
This has the advantage of completely eliminating shock noise when switching modes.

In particular, in the present invention, each heat exchange tube P in the second indoor coil 5
Because the flow path of the refrigerant flowing through the indoor fan has a specific form, during cooling operation, undehumidified high-temperature air and dehumidified low-temperature air mix in the indoor fan, causing condensation on the fan blades and causing water droplets to form. This has the effect of eliminating the inconvenient problem of air blowing out and scattering indoors.

[Brief explanation of the drawing]

Figure 1 is a device circuit diagram of an example of the air conditioner of the present invention, Figure 2 is a schematic structural diagram of an indoor unit according to an example of the present invention, and Figures 3 to 6 are each side of the present invention. FIG. 7 and FIG. 8 are device circuit diagrams of each side of a conventional air conditioner. 1...Compressor, 2...Outdoor coil, 3
...First indoor coil, 4...Capillary tube, 5...Second indoor coil, 5a.
...First heat exchange tube group, 5b... Second heat exchange tube group, 5C... Remaining heat exchange tube group, 5d...
... Outlet side heat exchange tube, 6 ... Indoor fan,
7... Liquid receiver, 8... Accumulator, 9... Refrigerant amount adjustment device, 10... Capillary tube, 11... Electromagnetic Valve, 12・
...Outdoor fan 1. P...Heat exchange tube.

Claims (1)

[Scope of utility model registration request] Between the discharge side and the suction side of the compressor 1, an outdoor coil 2. Air-type first indoor coil 3. A cross-fin coil heat exchanger equipped with a capillary tube 4 and two rows and multiple stages of heat exchange tubes, in which a second indoor coil 5 having a larger heat exchange area than the first indoor coil 3 is arranged in series in the order of description. They are connected to form a refrigerant circuit, and the refrigerant immediately after the capillary tube 4 flows through the second indoor coil 5 from approximately the center in the stage direction of the heat exchange tube P of the indoor coil 5. A plurality of heat exchange tubes P existing in the front row above the outlet side heat exchange tubes 5d directly above the first heat exchange tube group 5a in the heat exchange tube P in the front row are passed through the first heat exchange tube group 5a located on the lower stage side. and the uppermost heat exchange tube P in the rear row of heat exchange tubes P, and further passes through the remaining heat exchange tubes P to the outlet side heat exchange tube 5d. The second indoor coil 5 is configured as described above, while the first indoor coil 3 is configured as the second indoor coil 5.
The heat exchange tube group 5b is disposed on the upstream side of the circulating air flow path, and a refrigerant amount adjustment device 9 that can adjust the amount of stored refrigerant is provided at an appropriate location in the refrigerant circuit to adjust the amount of refrigerant. By deactivating the device 9, the amount of cooling of the second indoor coil 5 is made relatively large compared to the amount of heating of the first indoor coil 3 to enable cooling operation, while the refrigerant adjustment device 9 is activated. This air conditioner is characterized in that the heating amount of the first indoor coil 3 and the cooling amount of the second indoor coil 5 are almost balanced, thereby enabling dehumidifying operation.