Refrigeration equipment

Abstract

The present invention provides a refrigeration device capable of achieving energy saving regardless of temperature. The refrigeration device comprises a compressor (21), a condenser (22), a decompression device (32), and an evaporator (31). The condenser (22) is composed of a small condenser (23) and a spiral tube (51). A decompressor (50) is provided between the small condenser (23) and the spiral tube (51). The decompressor (50) is used to maintain the flow rate of the refrigerant at the inlet of the spiral tube (51) at a predetermined flow rate or higher. The decompressor vaporizes the refrigerant.

Description

Technical Field

[0001] The present invention relates to a refrigeration device using a spiral tube as a part of a condenser. Background Art

[0002] Generally, there is known a refrigeration device in which a condenser is composed of a combination of a fin-tube type small condenser and a spiral tube (for example, see Patent Document 1).

[0003] In this existing refrigeration device, a small condenser is used to partially liquefy the gas refrigerant, and the partially liquefied gas refrigerant is caused to flow into a spiral tube. Inside the tube, the refrigerant is accelerated to liquefy and cool with reduced pressure and enthalpy.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 5485602 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] However, in existing systems designed to partially liquefy the gas refrigerant using a small condenser during the warm summer months, for example, during the cool winter months, liquefaction of the gas refrigerant in the small condenser is accelerated, leading to a significant liquefaction rate. When the refrigerant, already liquefied at this rate, flows into the spiral tube, the flow velocity at the inlet of the spiral tube is slow, preventing sufficient acceleration of the refrigerant within the tube. Consequently, liquefaction and cooling, accompanied by reduced pressure and enthalpy within the tube, are insufficient, hindering energy efficiency in the refrigeration system.

[0009] The present invention has been made in order to solve the above-mentioned conventional problems, and an object of the present invention is to provide a refrigeration device that can achieve energy saving regardless of whether the temperature is high or low.

[0010] Solutions for solving problems

[0011] The present invention is characterized in that it comprises a compressor, a condenser, a pressure reducing device and an evaporator, wherein the condenser is composed of a small condenser and a spiral tube, and a pressure reducer is provided between the small condenser and the spiral tube, and the pressure reducer is used to maintain the flow rate of the refrigerant at the inlet of the spiral tube at a predetermined flow rate or above, and the pressure reducer vaporizes the refrigerant.

[0012] In the present invention, since a pressure reducer for vaporizing the refrigerant is provided between the small condenser and the spiral tube, even when the temperature is low and the liquefaction of the gas refrigerant in the small condenser is promoted and the gas refrigerant is liquefied in a considerable proportion, the flow velocity at the inlet of the spiral tube is maintained at above the predetermined flow velocity, and thus sufficient acceleration of the refrigerant can be obtained in the tube. The refrigerant can be fully liquefied and cooled in the tube along with the reduction of pressure and enthalpy, thereby achieving energy saving of the refrigeration device.

[0013] The present invention is characterized in that the predetermined flow rate is a rate at which the refrigerant flowing in the spiral tube is liquefied and cooled in the tube along with a reduction in pressure and enthalpy.

[0014] In the present invention, the refrigerant is fully liquefied and cooled in the tubes along with the reduction in pressure and enthalpy, and energy saving of the refrigeration apparatus can be achieved.

[0015] The present invention is characterized in that the pressure reducer is configured to partially vaporize the refrigerant liquefied by the small condenser when the air temperature is low.

[0016] In the present invention, since the refrigerant liquefied by the small condenser is partially vaporized when the temperature is low, the refrigerant is fully liquefied and cooled in the tubes with reduced pressure and enthalpy, thereby achieving energy saving of the refrigeration system.

[0017] The present invention is characterized in that the small condenser is configured to partially liquefy the gas refrigerant flowing into the small condenser when the air temperature is high.

[0018] In the present invention, since the gas refrigerant flowing into the small condenser is partially liquefied when the temperature is high, the refrigerant is fully liquefied and cooled in the tube with reduced pressure and enthalpy, thereby achieving energy saving of the refrigeration device.

[0019] The present invention is characterized in that the inner diameter of the pressure reducer is at least twice the inner diameter of the pipe.

[0020] In the present invention, since the inner diameter of the pressure reducer is more than twice the inner diameter of the piping, even when the temperature is low and the liquefaction of the gas refrigerant in the small condenser is promoted and the gas refrigerant is liquefied at a considerable proportion, the flow velocity at the inlet of the spiral tube is maintained at more than the predetermined flow velocity, and thus sufficient acceleration of the refrigerant can be obtained in the tube. The refrigerant can be fully liquefied and cooled in the tube along with the reduction of pressure and enthalpy, thereby achieving energy saving of the refrigeration device.

[0021] Effects of the Invention

[0022] In the present invention, sufficient acceleration of the refrigerant can be achieved in the spiral tube, and the refrigerant can be sufficiently liquefied and cooled in the tube along with reduced pressure and enthalpy, thereby achieving energy saving in the refrigeration system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a circuit configuration diagram showing one embodiment of the refrigeration system of the present invention.

[0024] Figure 2 It is the Ph diagram of the refrigeration device. DETAILED DESCRIPTION

[0025] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

[0026] exist Figure 1 In the figure, reference numeral 1 denotes an air conditioning device (refrigeration device).

[0027] This air-conditioning apparatus 1 is configured by connecting an outdoor unit 10 and an indoor unit 30 with a pipe 40 for R-134a refrigerant.

[0028] The indoor unit 30 includes a fin-and-tube evaporator 31 and an evaporator fan 31A.

[0029] The outdoor unit 10 includes a compressor 21, a fin-tube type small condenser 23, a condenser fan 23A, a cylindrical pressure reducer 50, a first tube 51 wound in a spiral shape, a second tube 52 wound in a spiral shape having a smaller winding diameter than the first tube 51, and a pressure reducing device 32. The small condenser 23, the pressure reducer 50, the first tube 51 wound in a spiral shape, and the second tube 52 wound in a spiral shape constitute the condenser 22.

[0030] Furthermore, the small condenser 23 is smaller than a condenser in the case where the first tube 51 and the second tube 52 are not used, and therefore is referred to as the small condenser 23 in the present embodiment.

[0031] Of course, the small condenser 23 may be the same size as a condenser without the first tube 51 and the second tube 52. For example, if the existing outdoor unit is a conventional outdoor unit equipped with a compressor, a fin-tube condenser, a condenser fan, and a pressure reducing device, the cylindrical pressure reducing device 50, the helically wound first tube 51, and the helically wound second tube 52 having a smaller winding diameter than the first tube 51 may be assembled between the condenser and the pressure reducing device by post-installation.

[0032] The first tube 51 and the second tube 52 are connected in series. Before the refrigerant discharged from the compressor 21 and liquefied by the small condenser 23 reaches the decompression device 32, the refrigerant is accelerated to liquefy and cool with decompression and enthalpy reduction.

[0033] The second tube 52 utilizes the acceleration phenomenon of the refrigerant to supercool the refrigerant that has passed through the first tube 51. The first tube 51 and the second tube 52 have the function of applying rapid rotation to the refrigerant to increase the flow rate of the refrigerant, thereby cooling or supercooling the refrigerant.

[0034] The first tube 51 is formed by spirally winding a thick tube. Its inner diameter and number of turns are determined by various specifications such as the discharge capacity and refrigeration capacity of the compressor 21. The allowable inner diameter is 2 to 150 mm, and the inner diameter is preferably 2 to 50 mm. The second tube 52 is formed by spirally winding a thin tube. Its inner diameter and number of turns are determined by various specifications such as the discharge capacity and refrigeration capacity of the compressor 21. The inner diameter of the second tube 52 is set to be smaller than that of the first tube 51. For example, if the throttle diameter of the pressure reducing device 32 is set to approximately 1 mm, the inner diameter of the second tube 52 is preferably 8 to 12 mm.

[0035] In this embodiment, one first tube 51 and one second tube 52 are provided in series. However, two or more sets of first tubes 51 and second tubes 52 may be connected in series and the sets may be connected in parallel to be assembled in the refrigerant circuit.

[0036] The first tubes 51 and second tubes 52 may be connected in series, spirally wound in different winding directions, or connected in parallel. The cross-sectional area of ​​the portion of the second tube 52 through which the refrigerant passes (the sum of the cross-sectional areas of the multiple tubes when multiple tubes are connected in parallel) is smaller than the cross-sectional area of ​​the first tube 51.

[0037] Furthermore, the first tube 51 and the second tube 52 , or the pipe 40 , are made of a metal with high thermal conductivity, such as copper.

[0038] Figure 2 This is a Ph diagram of the air-conditioning apparatus 1 according to this embodiment.

[0039] In this embodiment, when the compressor 21 is driven, Figure 1 As shown by the arrows, the refrigerant flows through the small condenser 23, the pressure reducer 50, the first pipe 51 and the second pipe 52 in sequence, passes through the pressure reducing device 32 and the evaporator 31, and then returns to the compressor 21.

[0040] The high-temperature (40°C or higher) and high-pressure (0.6 MPa or higher) gaseous refrigerant is discharged from the compressor 21. Figure 2From point m to point i), the refrigerant reaches the small condenser 23, where it is liquefied ( Figure 2 The refrigerant liquefied by the small condenser 23 flows through the pressure reducer 50 and enters the first tube 51. In terms of the cross-sectional area of ​​the refrigerant flow path, the cross-sectional area of ​​the refrigerant flow path in the first tube 51 is smaller than that of the small condenser 23, based on the small condenser 23.

[0041] When the refrigerant enters the first pipe 51, the refrigerant is accelerated by the suction action of the compressor 21 (called the refrigerant acceleration phenomenon), and the amount of liquefaction increases with the reduction of pressure and enthalpy, and the refrigerant is almost liquefied ( Figure 2 point j to point k).

[0042] The refrigerant becomes a medium-pressure liquid refrigerant on the discharge side of the first tube 51. The main reason for the temperature drop in the first tube 51 is that the enthalpy of the refrigerant as thermal energy is converted into kinetic energy in the first tube 51, and the enthalpy of the refrigerant decreases, causing the static temperature to drop.

[0043] The refrigerant that has become a medium-pressure liquid refrigerant in the first pipe 51 enters the second pipe 52. When the refrigerant that has almost liquefied enters the second pipe 52, the refrigerant is accelerated by the suction action of the compressor 21 (called the refrigerant acceleration phenomenon), and the liquefied refrigerant is supercooled ( Figure 2 At the discharge side of the second tube 52, the refrigerant is decompressed and cooled, becoming a low-temperature liquid. The pressure also decreases, becoming a low-pressure liquid.

[0044] The main reason for the temperature drop in the second tube 52 is the same as the temperature drop in the first tube 51 , that is, the enthalpy of the refrigerant as thermal energy is converted into kinetic energy, the enthalpy decreases, and the static temperature drops.

[0045] The refrigerant that has been supercooled and turned into a low-temperature liquid by passing through the second pipe 52 reaches the decompression device 32, where it is decompressed and sent to the evaporator 31. In the evaporator 31, the refrigerant evaporates ( Figure 2 Point l to point m), thus the refrigeration cycle ends.

[0046] In addition, the inventors of the present invention obtained the following through simulation.

[0047] This simulation was performed in a state where the pressure reducer 50 was not connected between the compact condenser 23 and the first pipe 51 .

[0048] For example, during the summer months when temperatures are high, the gas refrigerant is partially liquefied using the small condenser 23 at a gas:liquid ratio of 20%:80% (a first ratio). When the refrigerant flows into the first tube 51 at this first ratio, the refrigerant flow velocity at the inlet of the first tube 51 is 10 to 20 m / s (above a predetermined velocity).

[0049] At this flow rate, a sufficient acceleration phenomenon can be obtained in the first tube 51 , and the refrigerant in the first tube 51 is sufficiently liquefied and cooled with reduced pressure and enthalpy.

[0050] Refrigeration equipment can achieve energy savings of "15-20%".

[0051] However, when it is set to partially liquefy the refrigerant at the first ratio in the summer when the temperature is high, for example, in the winter when the temperature is low, the lower external temperature promotes the liquefaction of the gas refrigerant in the small condenser 23, and the liquefaction is carried out at a relatively large ratio, for example, "gas: liquid = 5~10%: 95~90%" (second ratio).

[0052] The second ratio has a higher liquid ratio than the first ratio.

[0053] When the refrigerant flows into the first tube 51 in the state of being liquefied to the second ratio in which the liquid ratio is higher, the flow velocity of the refrigerant at the inlet of the first tube 51 becomes slow to "3 to 5 m / s", and sufficient acceleration cannot be obtained in the first tube 51.

[0054] The energy saving at this time is about "5%".

[0055] By the way, when the refrigerant is made to flow into the first tube 51 in a state of complete liquefaction "gas: liquid = 0%: 100%" using the small condenser 23, the flow rate of the refrigerant at the inlet of the first tube 51 becomes slower, namely "2m / s", and sufficient acceleration cannot be obtained in the first tube 51.

[0056] The energy saving at this time is "5%" or less.

[0057] When the gas refrigerant is partially liquefied at "gas: liquid = 25%:75%" (the third ratio) using the small condenser 23 and the refrigerant in the third ratio state flows into the first tube 51, the flow rate of the refrigerant at the inlet of the first tube 51 is "25m / s" (above the predetermined flow rate).

[0058] Even at this flow rate, a sufficient acceleration phenomenon can be obtained in the first tube 51 , and the refrigerant can be sufficiently liquefied and cooled in the first tube 51 along with a reduction in pressure and enthalpy.

[0059] Refrigeration equipment can achieve energy saving.

[0060] The predetermined flow rate is a flow rate at which the refrigerant flowing through the first tube 51 is effectively liquefied and cooled with reduced pressure and enthalpy in the first tube 51 .

[0061] In this embodiment, if Figure 1 As shown, a pressure reducer 50 is connected between the small condenser 23 and the first tube 51. The pressure reducer 50 is used to maintain the flow rate of the refrigerant at the inlet of the first tube 51 above a predetermined flow rate, for example, "10 to 25 m / s". The pressure reducer 50 vaporizes the refrigerant.

[0062] The inner diameter of the pressure reducer 50 is at least twice, and preferably at least 2.5 times, the inner diameter of the pipe 40A on the inlet side of the pressure reducer 50 .

[0063] According to the structure of the refrigerant circuit, when the liquefaction of the gas refrigerant in the small condenser 23 is promoted, for example in winter when the temperature is low, the refrigerant temporarily flows into the pressure reducer 50 in a state liquefied to "gas: liquid = 5~10%: 95~90%" (second ratio).

[0064] The inner diameter of the pressure reducer 50 is at least twice the inner diameter of the pipe 40 . Therefore, the refrigerant flowing into the pressure reducer 50 is partially vaporized inside the pressure reducer 50 .

[0065] In the pressure reducer 50, in order to maintain the flow rate of the refrigerant at the inlet of the first tube 51 at a predetermined flow rate or above, for example, "10 to 25 m / s", the refrigerant at the outlet of the pressure reducer 50 is vaporized to a state of "gas: liquid = 20%:80%" (first ratio).

[0066] The numerical values ​​of the above-mentioned (first ratio), (second ratio), and (predetermined flow rate) can be appropriately changed according to the structure of the refrigeration system, and are not determined to be unique numerical values.

[0067] Furthermore, if the inner diameter of the pressure reducer 50 is too large, the ratio of gas to liquid in the refrigerant exceeds the first ratio, and the refrigerant tends to vaporize. If the refrigerant vaporizes too much, the liquefaction and cooling associated with the pressure reduction and enthalpy reduction in the first and second tubes 51 and 52 become insufficient, making it impossible to achieve sufficient energy savings.

[0068] In the present embodiment, since a pressure reducer 50 for vaporizing the refrigerant is provided between the small condenser 23 and the first tube 51, even when the temperature is low and the liquefaction of the gas refrigerant in the small condenser 23 is promoted and the gas refrigerant is liquefied at a considerable proportion, the flow velocity at the inlet of the first tube 51 is maintained at above the predetermined flow velocity. Therefore, sufficient acceleration of the refrigerant can be obtained in the first tube 51, and the coolant in the first tube 51 is sufficiently liquefied and cooled along with the pressure reduction and enthalpy reduction, thereby achieving energy saving of the refrigeration device.

[0069] The present invention has been described above based on one embodiment, but the present invention is not limited to application to air conditioners. For example, the refrigeration device of the present invention can also be applied to a refrigeration circuit of a point-type cooler.

[0070] Description of Reference Signs

[0071] 1. Air conditioning device (refrigeration device); 21. Compressor; 22. Condenser; 23. Small condenser; 31. Evaporator; 32. Pressure reducing device; 40. Piping; 50. Pressure reducer; 51. First tube wound in a spiral shape (spiral tube); 52. Second tube wound in a spiral shape.

Claims

1. A refrigeration device, characterized in that: The refrigeration device includes a compressor, a condenser, a pressure reducing device, and an evaporator. The condenser is composed of a small condenser and a spiral tube. A pressure reducer is provided between the small condenser and the spiral tube, the pressure reducer being used to maintain the flow rate of the refrigerant at the inlet of the spiral tube at a predetermined flow rate or higher. The predetermined flow rate is the rate at which the refrigerant flowing in the spiral tube is liquefied and cooled in the tube along with the reduction of pressure and enthalpy. The small condenser is configured to partially liquefy the gas refrigerant flowing into the small condenser at a certain ratio, and the pressure reducer is configured to vaporize the refrigerant when the ratio of liquefaction in the small condenser exceeds the certain ratio and liquefaction is promoted, thereby accelerating the refrigerant to maintain the flow rate of the refrigerant at the inlet of the spiral tube at the predetermined flow rate.

2. The refrigeration device according to claim 1, characterized in that The predetermined flow rate is 10-25 m / s.

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