JP6406485B1 - Air conditioning system - Google Patents

Abstract

Provided is an air conditioning system using a coiled thin tube and a coiled thick tube that can be efficiently operated during both cooling and heating. A cooling heat conversion unit having a cooling coil thick tube and a cooling coil thin tube, a heating coil thin tube, and a heating heat conversion unit having a heating coil thick tube, and a heating heat conversion unit The heating coil tubule of the present invention is characterized in that the flow path is formed thicker than the heating coil tubule of the cooling heat conversion section.

Description

  The present invention relates to an air conditioning system using a coiled thin tube and a coiled thick tube.

  Conventionally, an air conditioning system including a compressor, a use side heat exchanger, and a heat source side heat exchanger, and further using a coiled thin tube and a coiled thick tube is known (for example, see Patent Document 1).

JP 2010-281558 A

The cooling and heating system described in Patent Document 1 is operated using a common coiled thin tube and a thick coiled tube during cooling and heating.
However, it has been found that when the size of the flow path of the coiled thin tube and the coiled thick tube is set to an optimum size during cooling, an efficient operation cannot be performed during heating.
Accordingly, an object of the present invention is to provide an air conditioning system using a coiled thin tube and a thick coiled tube that can solve the above-described problems of the prior art and can be operated efficiently both during cooling and during heating. is there.

The present invention includes a compressor, a use side heat exchanger, and a heat source side heat exchanger, and accelerates the remaining gas refrigerant discharged from the compressor and partially liquefied by the heat source side heat exchanger during cooling. A cooling coil large pipe that is depressurized and liquefied by a phenomenon, a cooling heat conversion unit that has a cooling coil thin tube that depressurizes and cools the refrigerant that has passed through the cooling coil thick pipe by a refrigerant acceleration phenomenon, and at the time of heating, The refrigerant discharged from the compressor and liquefied by the use side heat exchanger is decompressed and partially vaporized by the acceleration phenomenon of the refrigerant, and the heating coil tubule and the refrigerant passing through the heating coil tubule are converted into the refrigerant acceleration phenomenon. A heating heat conversion unit having a heating coil thick tube that is depressurized and vaporized by the heating coil, the heating coil thin tube of the heating heat conversion unit is more than the cooling coil thin tube of the cooling heat conversion unit Thicken the flow path None No, characterized in that.

  In the present invention, the heating coil tubule of the heating heat conversion section is composed of an inlet side tubule and an outlet side tubule whose flow path becomes thicker in order from the refrigerant inlet side to the outlet side during heating, The cooling coil tubule of the cooling heat conversion unit is composed of an inlet side tubule and an outlet side tubule whose flow path becomes narrower in order from the refrigerant inlet side to the outlet side during cooling, and the heating heat converter unit The inlet side thin tube may be formed to have a larger flow path than the outlet side thin tube of the cooling heat conversion section.

  According to these inventions, since the inlet side thin tube of the heating heat conversion section is formed with a larger flow path than the outlet side thin tube of the cooling heat conversion section, it is possible to operate efficiently both during cooling and during heating. Can be performed.

In the present invention, the flow rates of the cooling heat conversion unit and the heating heat conversion unit may be set to be twice or more the flow rate of the heat source side heat exchanger.
In the present invention, the heat source side heat exchanger may be configured to liquefy 5 to 50% by weight of the high temperature / high pressure refrigerant gas discharged from the compressor during cooling.

  The air conditioning system of the present invention can perform an efficient operation both during cooling and during heating.

FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention. FIG. 2 is a circuit configuration diagram showing another embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a circuit diagram of an air conditioning cycle according to the present embodiment. Here, the terms “heat exchanger” and “heat converter” are used separately.
This air conditioning system is applied to a so-called separate type air conditioner in which an outdoor unit and an indoor unit are connected by a refrigerant pipe.
The air conditioning system includes a compressor 1, a cooling / heating switching valve (four-way valve) 2, a mini heat exchanger (heat source side heat exchanger) 3, a cooling heat conversion unit 4 in which coils are connected in series, and a coil in series. The heat conversion part 5 for heating connected to, and the use side heat exchanger 6 are provided. In the outdoor unit, a compressor 1, a four-way valve 2, a mini heat exchanger 3, a cooling heat conversion unit 4, and a heating heat conversion unit 5 are accommodated. Moreover, the use side heat exchanger 6 is accommodated in the indoor unit. The “mini” of the mini heat exchanger 3 means “small”, and is used to clarify the feature of the present invention that can make the mini heat exchanger 3 smaller than the conventional one.

In the cooling heat conversion unit 4, the refrigerant flows during the cooling operation.
The cooling heat conversion section 4 includes a cooling coil large pipe 41 that decompresses and liquefies the remaining gas refrigerant discharged from the compressor 1 and partially liquefied by the mini heat exchanger 3 due to the acceleration phenomenon of the refrigerant. Further, the cooling heat conversion unit 4 includes a cooling coil thin tube 42 that depressurizes and cools the refrigerant that has passed through the cooling coil thick tube 41 due to the acceleration phenomenon of the refrigerant. 43 is an on-off valve.

In the heating heat conversion section 5, the refrigerant flows during the heating operation.
The heating heat conversion section 5 includes a heating coil tubule 51 that depressurizes and partially vaporizes the refrigerant discharged from the compressor 1 and liquefied by the use side heat exchanger 6 by the acceleration phenomenon of the refrigerant. Further, the heating heat conversion section 5 includes a heating coil thick tube 52 that depressurizes and vaporizes the refrigerant that has passed through the heating coil capillary 51 due to the acceleration phenomenon of the refrigerant. 53 is an on-off valve.

The cooling coil thick tube 41 and the heating coil thick tube 52 are formed by winding a thin tube in a coil shape, and the flow passage areas are equal and the lengths are set to be equal.
The inner diameter and the number of turns are determined from various specifications such as the refrigeration capacity of the air conditioning system, but the inner diameter is allowed to be 2 to 150 mm, preferably 2 to 50 mm, substantially most preferably 3 to 8 mm. is there. For example, a refrigerator of about 2000 cal / h using Freon refrigerant R134a, an inner diameter of a thin tube of 5 mm, a number of turns of 23, a diameter of a coil of 30 mm, and a length of the thin tube of 2.3 m.
In this embodiment, the cooling coil thick tube 41 and the heating coil thick tube 52 are provided separately, but these thick tubes may be shared to form one coil thick tube. In this case, the refrigerant flows through one coil thick tube both during cooling and during heating. In the case of a single coil large tube, the configuration of the refrigerant circuit can be simplified.

The cooling coil thin tube 42 and the heating coil thin tube 51 are formed by winding a thin tube in a coil shape, like the coil thick tubes 41 and 52.
The inner diameter and the number of windings are determined from various specifications such as the refrigeration capacity of the air conditioning system. For example, when the inner diameters of the coil thick tubes 41 and 52 are set to 3 to 8 mm, the inner diameters of the coil thin tubes 42 and 51 are desirably 1 to 3 mm.

In the present embodiment, the inside diameter of the heating coil capillary 51 is set larger than the inside diameter of the cooling coil capillary 42.
The inner diameter and the number of windings are determined from various specifications such as the cooling capacity of the air conditioning system. For example, when the inner diameter of the cooling coil capillary 42 is set to 1.9 mm or less, the inner diameter of the heating coil capillary 51 Is 2.0 mm or more.

In the present embodiment, there is one cooling coil thin tube 42 and one heating coil thin tube 51. However, the coil thin tubes 42 and 51 may be formed by connecting two coiled tubes in parallel. good. Moreover, the form which connected 3 or more in parallel may be sufficient.
The coil capillaries 42 and 51 may have a configuration in which two coils wound in different winding directions are connected in series, or may be connected in parallel. The cross-sectional area of the portion through which the refrigerant passes through the coiled tubes 42 and 51 (the sum of the plurality of cross-sectional areas connected in parallel is smaller than the cross-sectional area of the coiled thick tubes 41 and 52). Is preferred. When the cross-sectional area is reduced, as will be described later, the refrigerant spins and accelerates in the coil capillaries 42 and 51, the pressure is reduced, and the cooling effect is enhanced.

Next, the operation of this embodiment will be described.
<When cooling>
At the time of cooling, the four-way valve 2 is switched to the dashed cooling position, the on-off valve 53 is closed, and the on-off valve 43 is opened. When the compressor 1 is driven, the refrigerant flows in the order of the four-way valve 2, the mini heat exchanger 3, and the cooling heat conversion unit 4 in which the two coils are connected in series, as indicated by the dashed arrows, and uses side heat exchange. After passing through the unit 6, the process returns to the compressor 1.

During cooling, when a high-temperature (40 ° C. or higher) and high-pressure (0.6 MPa or higher) gaseous refrigerant is discharged from the compressor 1, a part of the refrigerant (5 to 50 wt%) is discharged from the mini heat exchanger 3 Only configured to liquefy.
In conventional condensers for air conditioning systems, almost all of the high-temperature / high-pressure gas discharged from the compressor 1 is liquefied, but the mini heat exchanger 3 of this embodiment is one of the high-temperature / high-pressure gases. Only the part needs to be liquefied.
Therefore, downsizing is possible. Compared to an air-conditioning system having the same cooling capacity and having the same type of heat exchanger (condenser), the mini heat exchanger 3 of the present embodiment can be made about 1/10 of a conventional condenser.

  The refrigerant partially liquefied by the mini heat exchanger 3 enters the cooling coil thick tube 41. When viewed from the cross-sectional area of the refrigerant flow path, the cooling coil thick tube 41 is smaller than the cross-sectional area of the mini heat exchanger 3 with respect to the mini heat exchanger 3.

When the partially liquefied refrigerant enters the cooling coil thick tube 41, the refrigerant is accelerated by the suction action of the compressor 1 (referred to as an acceleration phenomenon of the refrigerant), and the amount of liquefaction is reduced with reduced pressure and enthalpy reduction. It becomes almost liquefied.
On the outlet side of the cooling coil thick tube 41, the liquid refrigerant has an intermediate pressure (0.4 to 0.6 MPa). The main cause of the temperature decrease in the cooling coil thick tube 41 is that the enthalpy of the refrigerant, which is thermal energy, is converted into velocity energy in the cooling coil thick tube 41, and the enthalpy of the refrigerant decreases, resulting in a phenomenon of a decrease in static temperature. It was the birth.
The flow rate in the cooling coil thick tube 41 is preferably set to be at least twice the flow rate in the mini heat exchanger 3 in the design of the present cooling and heating system.

The refrigerant that has become medium-pressure liquid refrigerant in the cooling coil large tube 41 enters the cooling coil thin tube 42.
When the almost liquefied refrigerant enters the cooling coil capillary 42, the refrigerant is accelerated by the suction action of the compressor 1 or the like (referred to as an acceleration phenomenon of the refrigerant), and the liquefied refrigerant is cooled with reduced pressure and enthalpy reduction. The On the outlet side of the cooling coil capillary 42, the pressure is reduced and cooled to become a low-temperature liquid, and the pressure is lowered to a low-pressure (0.4 MPa or less) liquid.
The main cause of the temperature decrease in the cooling coil thin tube 42 is that, similarly to the temperature decrease in the cooling coil thick tube 41, the enthalpy of the refrigerant, which is thermal energy, is converted into velocity energy, and the enthalpy is reduced. This led to the phenomenon of temperature drop. The flow rate in the cooling coil thin tube 42 is preferably at least twice the flow rate in the mini heat exchanger 3 and higher than the flow rate in the cooling coil large tube 41 in the design of the present cooling and heating system.

  The refrigerant that has become a low-temperature liquid by the cooling coil capillary 42 is sent to the use-side heat exchanger 6. In the use-side heat exchanger 6, the refrigerant evaporates due to the endothermic heat of isobaric and isothermal expansion, thereby completing the cooling cycle.

<When heating>
At the time of heating, the four-way valve 2 is switched to the solid heating position, the on-off valve 53 is opened, and the on-off valve 43 is closed. When the compressor 1 is driven, the refrigerant flows in the order of the four-way valve 2, the use side heat exchanger 6, and the heating heat conversion unit 5 in which two coils are connected in series, as indicated by solid arrows, and mini heat exchange is performed. After passing through the unit 3, it returns to the compressor 1.

During heating, when a high-temperature (40 ° C. or higher) and high-pressure (0.6 MPa or higher) gaseous refrigerant is discharged from the compressor 1, the refrigerant is liquefied in the use-side heat exchanger 6.
The refrigerant liquefied by the use side heat exchanger 6 enters the heating coil tubule 51. When viewed from the cross-sectional area of the refrigerant flow path, the heating coil capillary 51 is smaller than the cross-sectional area of the usage-side heat exchanger 6 with respect to the usage-side heat exchanger 6.

When the heating coil tubule 51 is entered, the refrigerant is accelerated by the suction action of the compressor 1 or the like (referred to as an acceleration phenomenon of the refrigerant), and is partially vaporized with reduced pressure and enthalpy reduction.
At this time, since the inner diameter of the heating coil capillary 51 is set to be larger than the inner diameter of the cooling coil capillary 42, the heating coil capillary 51 is partially vaporized without much lowering the temperature.
On the outlet side of the heating coil capillary 51, the refrigerant is partially vaporized at a medium pressure (0.4 to 0.6 MPa). The main cause of the temperature drop in the heating coil tubule 51 is that the enthalpy of the refrigerant, which is thermal energy, is converted into speed energy in the heating coil tubule 51, and the enthalpy of the refrigerant is reduced, causing the phenomenon of a decrease in static temperature It has come.
The flow rate in the heating coil capillary 51 is desirably set to be twice or more the flow rate in the use-side heat exchanger 6 in the design of the cooling / heating system.

The refrigerant partially vaporized in the heating coil thin tube 51 enters the heating coil thick tube 52.
When entering the heating coil thick tube 52, the refrigerant is accelerated by the suction action of the compressor 1 (referred to as an acceleration phenomenon of the refrigerant), and the refrigerant is vaporized with reduced pressure and enthalpy reduction. On the outlet side of the heating coil thick tube 52, the pressure is reduced and cooled, and the pressure is lowered to become a low-pressure (0.4 MPa or less) gas refrigerant.
The main cause of the temperature drop in the heating coil thick tube 52 is that, similarly to the temperature drop in the heating coil thin tube 51, the enthalpy of the refrigerant, which is thermal energy, is converted into velocity energy, the enthalpy is reduced, and the static temperature This has led to the phenomenon of decline.

  The gas refrigerant whose temperature has been lowered by the heating coil thick tube 52 is sent to the mini heat exchanger 3. In this mini heat exchanger 3, the refrigerant evaporates due to the endothermic heat of isobaric and isothermal expansion, thereby completing the heating cycle.

In a conventional cooling / heating system (for example, see Patent Document 1), the inner diameter of the heating coil thin tube 51 and the inner diameter of the cooling coil thin tube 42 are set to be equal, so that efficient operation can be performed during cooling. However, there is a problem that the temperature of the refrigerant is too low when the pressure is reduced in the heating coil capillary 51 during heating. This is because the design of the air conditioning system is designed in consideration of the efficiency during cooling.
In the present embodiment, as described above, since the inner diameter of the heating coil capillary 51 is set larger than the inner diameter of the cooling coil capillary 42, the temperature of the refrigerant is reduced when the heating coil capillary 51 is depressurized. There is not much lowering.
Therefore, since the temperature of the gas refrigerant returned to the compressor 1 becomes relatively high, the efficiency of the heating cycle can be improved.
Efficiency during cooling is ensured, efficiency is ensured even during heating, and efficient operation can be performed both during cooling and heating.

FIG. 2 shows another embodiment. In FIG. 2, parts having the same configuration as in FIG.
In this embodiment, the heating coil thin tube 51 of the heating heat conversion section 5 has an inlet thin tube 51A, and a flow passage that gradually increases in thickness from the refrigerant inlet side to the outlet side during heating. Is also composed of an outlet side thin tube 51B having a large inner diameter.
Further, the cooling coil thin tube 42 of the cooling heat conversion unit 4 has an inner diameter smaller than that of the inlet thin tube 42A so that the flow path becomes narrower in order from the refrigerant inlet side to the outlet side during cooling. It is comprised by the small exit side thin tube 42B.
The inlet side thin tube 51A of the heating heat conversion unit 5 has a larger flow path and a larger inner diameter than the outlet side thin tube 42B of the cooling heat conversion unit 4.

The present inventors configured the heating coil tubule 51 by an entrance side tubule 51A and an exit side tubule 51B having an inner diameter larger than that, and the cooling coil tubule 42 by an entrance side tubule 42A. When the inner diameter of the inlet side thin tube 51A of the heating coil thin tube 51 is set to be larger than the inner diameter of the outlet side thin tube 42B of the cooling coil thin tube 42, when it is configured by the outlet thin tube 42B having a small inner diameter, It was confirmed that the efficiency could be improved.
According to this embodiment, since the inner diameter of the inlet side thin tube 51A of the heating coil thin tube 51 is set larger than the inner diameter of the outlet side thin tube 42B of the cooling coil thin tube 42, the inlet side thin tube 51A is depressurized. In this case, the temperature of the refrigerant is not lowered too much. Therefore, similarly to the embodiment of FIG. 1, the temperature of the gas refrigerant returned to the compressor 1 becomes relatively high, and the efficiency of the heating cycle can be improved.

  As mentioned above, although the air conditioning system of this invention was demonstrated based on one Embodiment, this invention is not limited to this. For example, the present invention can be applied not only to an outdoor unit and an air conditioner separated into an indoor unit, but also to an integrated air conditioner.

1 Compressor 3 Mini heat exchanger (heat source side heat exchanger)
DESCRIPTION OF SYMBOLS 4 Heat conversion part for cooling 5 Heat conversion part for heating 6 Use side heat exchanger 41 Coil large tube for cooling 42 Coil thin tube for cooling 42A Inlet side thin tube of the heat conversion part for cooling 42B Outlet side thin tube of the heat conversion part for cooling 51 Heating coil thin tube 51A Heating heat conversion unit inlet side thin tube 51B Heating heat conversion unit outlet thin tube 52 Heating coil thick tube

Claims (4)

It is equipped with a compressor, use side heat exchanger, heat source side heat exchanger,
During cooling, the remaining gas refrigerant discharged from the compressor and partially liquefied by the heat source side heat exchanger is decompressed and liquefied by the acceleration phenomenon of the refrigerant, and the cooling coil large pipe A cooling heat conversion section having a cooling coil capillary that depressurizes and cools the refrigerant that has passed through the acceleration phenomenon of the refrigerant;
During heating, the refrigerant discharged from the compressor and liquefied by the use side heat exchanger is decompressed and partially vaporized by the acceleration phenomenon of the refrigerant, and the heating coil tubule, and the refrigerant that has passed through the heating coil tubule, A heating heat conversion section having a heating coil thick tube that is decompressed and vaporized by the acceleration phenomenon of the refrigerant,
The heating coil tubule of the heating heat conversion section has a channel formed thicker than the cooling coil tubule of the cooling heat conversion section.
An air conditioning system characterized by that. The heating coil tubule of the heating heat conversion section is composed of an inlet side tubule and an outlet side tubule whose flow path becomes thicker in order from the inlet side to the outlet side of the refrigerant during heating,
The cooling coil tubule of the cooling heat conversion section is composed of an inlet-side tubule and an outlet-side tubule whose flow path becomes narrower in order from the refrigerant inlet side to the outlet side during cooling,
The inlet side thin tube of the heating heat conversion part is formed thicker than the outlet side thin tube of the cooling heat conversion part,
The air conditioning system according to claim 1. The flow rates of the cooling heat conversion unit and the heating heat conversion unit are set to be twice or more the flow rate in the heat source side heat exchanger,
The air-conditioning system according to claim 1 or 2 characterized by things. The heat source side heat exchanger is configured to liquefy 5 to 50% by weight of the high-temperature / high-pressure refrigerant gas discharged from the compressor during cooling.
The air conditioning system according to any one of claims 1 to 3, wherein

Images