JP2013204981A - Cooling unit and refrigeration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling unit capable of effectively carrying out supercooling of a refrigerant flowing in an inlet pipe connected to an inlet of an evaporator through an expansion valve, and remarkably reducing worker's burden when installed.SOLUTION: In a cooling coil 10 arranging an evaporator 16 in one side of a surface of a drain pan 11, and arranging a blower 18 generating an air flow passing the evaporator 16 in another side of the surface of the drain pan 11, an inlet pipe 12 connected to an inlet of the evaporator 16 is arranged to meander so as to contact with the back side of the drain pan 11.

Description

  The present invention relates to a cooling unit and a refrigeration apparatus installed in a space to be cooled such as a prefabricated refrigerator.

  Generally, in a space to be cooled such as a prefabricated refrigerator (refrigeration apparatus), a cooling unit is installed, for example, in a ceiling manner. This cooling unit accommodates an evaporator and a blower, and the evaporator is connected to a refrigerator. This refrigerator has a compressor, a condenser, and an expansion valve, and these devices are connected to an evaporator to constitute a refrigeration cycle. In this type of apparatus, in order to improve heat exchange efficiency and COP, for example, the inlet pipe of the expansion valve and the outlet pipe of the evaporator are arranged so as to contact each other, and the inlet pipe and the outlet pipe It has been proposed to perform heat exchange between the two and supercool the refrigerant toward the evaporator (see, for example, Patent Document 1).

JP-A-9-60989

However, in the conventional refrigeration apparatus, the operation of bringing the inlet pipe and the outlet pipe into contact with each other is performed at the site when the refrigeration apparatus is installed.
For the operator, the inlet pipe and the outlet pipe must be provided in contact with each other, for example, by taking a tight posture, and the refrigeration apparatus is caused by the troublesome work of installing the inlet pipe and the outlet pipe. The burden of installation work has increased.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-described problems of the prior art and to obtain a cooling unit and a refrigeration apparatus that can sufficiently subcool the refrigerant flowing through the inlet pipe and reduce the burden on the operator. .

In order to achieve the above object, the present invention provides a cooling unit in which an evaporator is disposed on one side of a surface of a drain pan, and a blower that generates an airflow passing through the evaporator is disposed on the other side of the surface. The inlet pipe connected to the evaporator is arranged to meander so as to contact the back surface of the drain pan.
In the present invention, since the refrigerant flowing in the inlet pipe is cooled by the cold heat of the drain water stored in the drain pan and flows into the evaporator, it is supercooled, thereby improving the heat exchange efficiency and improving the COP.
In this case, the connection port of the inlet pipe and the outlet port of the evaporator may be provided exposed to the outside of the drain pan.
Moreover, the said cooling unit may be installed toward the to-be-cooled space, such as a prefabricated refrigerator, the back surface of the said drain pan.
The cooling unit may be suspended from a ceiling such as a prefabricated refrigerator.

  According to the present invention, since the refrigerant flowing in the inlet pipe is cooled by the cold heat of the drain water stored in the drain pan and flows into the evaporator, it is supercooled, thereby improving the heat exchange efficiency and improving the COP. In addition, since the inlet pipe can be attached to the back surface of the drain pan in advance during the manufacture of the cooling unit, it is possible to omit the work of installing the inlet pipe by taking a cramped posture at the site when installing the cooling unit.

It is a layout view of a refrigeration apparatus according to an embodiment of the present invention. It is a refrigerant circuit figure of a freezing apparatus. It is sectional drawing of a cooling coil (cooling unit). It is a bottom view of a cooling coil (cooling unit).

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, R indicates a refrigeration apparatus (for example, a prefabricated refrigerator-freezer).
The refrigeration apparatus R includes a cooling coil (cooling unit) 10 and a refrigerator 30. The cooling coil 10 is suspended from the ceiling 1 b of the space 1 a to be cooled of the prefabricated freezer 1 via the metal fitting 2, and the refrigerator 30 is provided outside the prefabricated freezer 1.

FIG. 2 is a refrigerant circuit diagram of the refrigeration apparatus R.
The refrigeration cycle formed by the refrigerant circuit C includes a cooling coil 10 and a refrigerator 30 and uses carbon dioxide having a high-pressure side refrigerant pressure (high-pressure) that is equal to or higher than the critical pressure (supercritical) as a refrigerant. This carbon dioxide refrigerant is a natural refrigerant that is friendly to the global environment and takes into consideration flammability and toxicity.
The refrigerator 30 includes two two-stage compressors 31 and 31 arranged in parallel. The two-stage compressors 31, 31 are internal intermediate pressure type multi-stage compression rotary compressors, cylindrical sealed containers 32, 32 made of steel plates, and a drive unit disposed and housed in the internal space of the sealed containers 32, 32. (Not shown), and a first rotary compression element (first stage compressor) 33, 33 and a second rotary compression element (second stage compressor) 34, 34 that are rotationally driven by a driving machine. . The first rotary compression elements 33, 33 are used on the lower pressure side than the second rotary compression elements 34, 34.

Low pressure pipes 35, 35 are connected to the refrigerant suction portions of the first rotary compression elements 33, 33. The low-pressure refrigerant sucked into the first rotary compression elements 33, 33 is compressed by the first rotary compression elements 33, 33 to be increased to an intermediate pressure, and serves as a refrigerant discharge port for the first rotary compression elements 33, 33. It is discharged from the side discharge ports 37 and 37.
A first intermediate pressure pipe 38 is connected to the lower stage discharge ports 37 of the two-stage compressors 31, 31, and the first intermediate pressure pipe 38 joins downstream and is connected to the inlet of the intercooler 39. Has been. A second intermediate pressure pipe 40 is connected to the outlet of the intercooler 39 and branched downstream, and each of the branched second intermediate pressure pipes 40 serves as a refrigerant suction portion for the second rotary compression elements 34 and 34. It is connected to the stage side suction ports 41, 41.
The intercooler 39 air-cools the intermediate-pressure refrigerant gas flowing in from the low-stage discharge ports 37, 37, and the cooled refrigerant gas passes through the second intermediate-pressure pipe 40 to the high-stage suction port. 41 is sucked into the second rotary compression elements 34, 34. The second rotary compression elements 34, 34 compress the intermediate pressure refrigerant (gas) and discharge it from the high-stage discharge ports 43, 43 in a high temperature and high pressure state.

The first high-pressure pipes 44 and 44 are connected to the high-stage discharge ports 43 and 43 of the second rotary compression elements 34 and 34, and merge at the downstream side. The joined first high-pressure pipe 44 is an oil separator 46. Is connected to the inlet of the gas cooler 47.
Furthermore, the outlet of the gas cooler 47 and the intermediate heat exchanger 60 are connected via a second high-pressure pipe 48. That is, the refrigerant discharged from the high-stage discharge ports 43, 43 is oil-removed by the oil separator 46, flows into the gas cooler 47, and is air-cooled. The oil separator 46 is provided with an oil pipe 52 extending from the oil cooler 51 to the two-stage compressors 31, 31, and the oil removed by the oil separator 46 is air-cooled by the oil cooler 51, The two-stage compressors 31 and 31 are returned.

  The gas cooler 47 cools the high-pressure refrigerant discharged from the two-stage compressors 31, 31, and a refrigerator side blower 49 that cools the gas cooler 47 in the vicinity of the gas cooler 47 is disposed. In the present embodiment, the gas cooler 47, the intercooler 39, and the oil cooler 51 are arranged in parallel, and these are arranged in the same air passage 53 and cooled by cooling air driven by the same refrigerator-side blower 49. Is done.

The intermediate heat exchanger 60 has a first flow path 60A and a second flow path 60B, and one end (inlet) of the first flow path 60A and an outlet of the gas cooler 47 are connected via a second high-pressure pipe 48. ing. One end of the third high-pressure pipe 55 is connected to the outlet of the first flow path 60A.
The refrigerant flowing into the gas cooler 47 is forcibly cooled by air, discharged from the gas cooler 47, and flows into the first flow path 60 </ b> A of the intermediate heat exchanger 60.
One end of the second flow path 60B and a predetermined portion of the third high-pressure pipe 55 are connected by a first split pipe 68. A strainer 71 and an intermediate expansion valve 72 are incorporated in the first split pipe 68. Further, the second split pipe 69 connects the other end of the second flow path 60 </ b> B and a predetermined portion of the second intermediate pressure pipe 40 connected to the outlet of the gas cooler 47.
In the intermediate heat exchanger 60, heat exchange is performed between the refrigerant that has flowed from the gas cooler 47 into the first flow path 60A and the refrigerant that has passed through the first flow path 60A and has been appropriately depressurized by the intermediate expansion valve 72. The refrigerant in the first flow path 60 </ b> A is cooled by the refrigerant in the second flow path 60 </ b> B and sent to the third high-pressure pipe 55.

In addition, the refrigerant that has passed through the second flow path 60B is warmed by taking the heat of the refrigerant in the first flow path 60A, and then returned to the second intermediate pressure pipe 40 through which the intermediate-pressure refrigerant flows to be sucked into the higher stage. The air is sucked into the second rotary compression elements 34 and 34 from the ports 41 and 41.
The first split pipe 68, the second flow path 60B, and the second split pipe 69 provided with the intermediate expansion valve 72 constitute a split circuit C2 for cooling the refrigerant supplied to the cooling coil 10.
One end of the inlet pipe 12 of the cooling coil 10 is connected to the other end of the third high-pressure pipe 55 via the refrigerant feed pipe 17a, so that the refrigerant sent from the refrigerator 30 flows into one end of the inlet pipe 12. It has become. The inlet tube 12 is made of, for example, copper.
An expansion valve 14 is connected to the other end of the inlet pipe 12, and the expansion valve 14 is connected to the evaporator 16 of the cooling coil 10. One end of the refrigerant return pipe 17b is connected to the evaporator 16, and the other end of the refrigerant return pipe 17b is connected to the low pressure pipes 35, 35. The low pressure pipes 35, 35 are in the first rotation as described above. It is connected to the refrigerant suction part of the compression elements 33, 33.
As described above, the refrigerant circuit C includes the refrigerant main circuit C1 having the cooling coil 10 and the refrigerator 30 as paths, and the split circuit C2 for cooling the refrigerant sent to the cooling coil 10.

FIG. 3 is a sectional view of the cooling coil 10, and FIG. 4 is a bottom view of the cooling coil 10.
As shown in FIGS. 1 and 3, the cooling coil 10 includes a drain pan 11 made of, for example, stainless steel. The evaporator 16 is disposed on the surface of the drain pan 11, that is, on the upper end of one end and the other end of the drain pan 11. And the air blower 18 is arrange | positioned.
The drain pan 11 includes a bottom portion 11 a having a rectangular outer shape and a side wall portion 11 b that protrudes from the entire outer peripheral edge of the bottom portion 11 a to the surface side, and the entire opening side is covered with a case 20.
On the back surface of the drain pan 11 (bottom portion 11a), a drain pipe 13 for draining the accumulated drain water is projected. The back surface of the bottom part 11a is exposed to the cooled space 1a.
The blower 18 is supported by the case 20 and the drain pan 11 via the support frame 18c. The blower 18 includes a blade portion 18a and a motor 18b that generates a driving force for rotationally driving the blade portion 18a.

In the present embodiment, as shown in FIG. 4, a part of the inlet pipe 12 to the evaporator 16 is attached in close contact with the back surface of the bottom part 11 a of the drain pan 11 with its main part meandering.
The inlet pipe 12 meanders so as to extend in a reciprocating manner in substantially the entire length of the back surface of the drain pan 11, and the inlet pipe 12 has a plurality of linear portions 12b located between the reversing portions 12a arranged in parallel to each other. ing.

The inlet pipe 12 is fixed by a fixing bracket 25 so as to be pressed against the back surface of the drain pan 11.
As shown in FIGS. 3 and 4, the fixing bracket 25 is a pair of flat plate-shaped fixing portions 26 and a pair of semicircular sections that are continuous on both sides of the fixing portion 26 and have openings arranged in the same direction. And a tube holding portion 27.
The fixing bracket 25 has the fixing portion 26 fixed to the back surface of the bottom portion 11a positioned between the adjacent linear portions 12b, and the linear portions 12b positioned on both sides of the fixing portion 26 on the inner peripheral side of the pair of tube holding portions 27. The inlet pipe 12 is supported by fitting.
At this time, the tube holding portion 27 is configured to exert an elastic force that presses the linear portion 12b against the back surface of the bottom portion 11a.

In addition, the inlet port 15a and the outlet port 15b of the evaporator 16 extend through the bottom 11a of the drain pan 11 and extend from the back surface of the bottom 11a, respectively, and are positioned on one end side in the short direction of the bottom 11a. ing. The inlet port 15a is located near one end in the longitudinal direction of the bottom portion 11a, and the outlet port 15b is located near the other end in the longitudinal direction of the bottom portion 11a.
Then, the refrigerant outlet of the expansion valve 14 is connected to the inlet port 15a, and the other end side of the inlet pipe 12 extends from one end side in the short direction of the bottom portion 11a and from one end in the longitudinal direction of the bottom portion 11a, It is connected to the refrigerant inlet of the expansion valve 14.
In addition, one end (connection port) of the inlet pipe 12 extends from the other end side in the short direction of the bottom portion 11 a and from the vicinity of the other end in the longitudinal direction of the bottom portion 11 a and extends from the refrigerant feed port 30 a of the refrigerator 30. It is connected to the refrigerant feed pipe 17a. One end of the refrigerant return pipe 17b is connected to the outlet port 15b, and the other end is connected to the low-pressure pipe 35 of the refrigerator 30.
Thus, the inlet pipe 12 is provided meandering so as to be as long as possible over the entire back surface of the bottom portion 11a.
Further, a heating wire 28 as a heating means is provided meandering on the surface side of the drain pan 11 like the inlet pipe 12. By energizing the heating wire 28, for example, drain water staying in the drain pan 11 is evaporated.

In the cooling coil 10 of this embodiment, an evaporator 16 is disposed on one side of the surface of the drain pan 11, and a blower 18 that generates an airflow passing through the evaporator 16 is disposed on the other side of the surface of the drain pan 11. An inlet pipe 12 connected to 16 inlets is attached to the back surface of the drain pan 11.
Since the operation of fixing the inlet pipe 12 to the back surface of the drain pan 11 can be performed in advance at the time of manufacturing the cooling coil 10, not at the installation site of the refrigeration apparatus R, a tight posture at the site when the cooling coil 10 is installed. Thus, the work of installing the inlet pipe 12 can be omitted. The refrigerant flowing through the inlet pipe 12 is air-cooled in the cooled prefabricated freezer 1. At this time, an air flow is also generated around the inlet pipe 12 by driving the blower 18, so that the inlet pipe 12 is effectively cooled.
Furthermore, since the inlet pipe 12 is in contact with the drain pan 11, heat exchange is performed with the drain pan 11, and the inlet pipe 12 can be cooled more effectively.
That is, according to the cooling coil 10 of the present embodiment, it is possible to effectively supercool the refrigerant while reducing the work burden when the worker is installed.

Further, since the inlet pipe 12 is fixed to the back surface of the drain pan 11, the airflow passing through the evaporator 16 is not disturbed by the inlet pipe 12, and the inlet pipe 12 is cooled by the cooling coil 10. It does not lead to a decrease in.
Further, since the inlet pipe 12 is fixed to the back surface of the drain pan 11, the vibration of the inlet pipe 12 is suppressed. Thereby, the durability of the inlet pipe 12 can be ensured.
Here, as the refrigerant, a carbon dioxide refrigerant that has a high pressure but a low critical point and is difficult to take a temperature difference from the outside air is used. In this case, the heat of the inlet pipe 12 and the air around the inlet pipe 12 is heated. It is difficult to cool the refrigerant by replacement. In order to sufficiently subcool the carbon dioxide refrigerant, it is necessary to take the length of the inlet pipe 12. However, in the cooling coil 10, the inlet pipe 12 is meanderingly arranged. The cooling effect of the refrigerant flowing through the inlet pipe 12 can be enhanced.

Moreover, when the drain pan 11 is frosted, it is necessary to energize the heating wire 28 to warm the drain pan 11 to perform defrosting.
In the cooling coil 10, the inlet pipe 12 through which a refrigerant having a higher temperature than that in the prefabricated freezer 1 is brought into contact with the drain pan 11. Therefore, heat exchange is also performed between the drain pan 11 and the inlet pipe 12, and the inlet pipe 12 is cooled. On the other hand, the drain pan 11 is warmed.
Thereby, it is hard to form frost on the drain pan 11, and even if frost is formed, the power supplied to the heating wire 28 necessary for defrosting can be reduced.
Moreover, since the inlet pipe 12 is brought into contact with the back surface of the drain pan 11 and the inlet pipe 12 is not attached to the drain water, deterioration of the inlet pipe 12 due to electrolytic corrosion can be suppressed.

  Moreover, it extends from the fixing | fixed part 26 fixed to the drain pan 11, and presses the inlet pipe 12 to the drain pan 11 with an elastic force, in other words, the pipe which exhibits and holds the biasing force which presses the inlet pipe 12 against the drain pan 11. Since the fixing fitting 25 having the holding portion 27 is provided, the inlet pipe 12 can be cooled while reliably holding the inlet pipe 12 pressed against the drain pan 11 and reliably suppressing vibration of the inlet pipe 12. .

Carbon dioxide is used as the refrigerant. Carbon dioxide is easy to manage refrigerant without toxicity or flammability. In addition, although the case where the carbon dioxide was used was mentioned as an example as a refrigerant | coolant, the effect of this application can be acquired even if it uses another refrigerant | coolant.
Moreover, although the cooling unit was demonstrated as what is the cooling coil 10 provided in the prefabricated freezer 1, For example, it has the structure similar to the cooling coil 10, and can be utilized also for what is accommodated in a large sized showcase etc.

10 Cooling coil (cooling unit)
11 Drain pan 12 Inlet pipe 15b Outlet port 16 Evaporator R Refrigeration equipment

Claims (4)

In the cooling unit in which an evaporator is arranged on one side of the surface of the drain pan, and a blower that generates an airflow passing through the evaporator is arranged on the other side of the surface,
A cooling unit, wherein an inlet pipe connected to the evaporator is arranged to meander so as to contact the back surface of the drain pan.   The cooling unit according to claim 1, wherein a connection port of the inlet pipe and an outlet port of the evaporator are provided so as to be exposed to the outside of the drain pan.   The cooling unit according to claim 1 or 2, wherein the cooling unit is installed with a back surface of the drain pan facing a space to be cooled such as a prefabricated refrigerator.   The refrigeration apparatus according to claim 3, wherein the cooling unit is installed in a ceiling manner on a top surface of a prefabricated refrigerator or the like.

Images