JP2007255727A - Refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost refrigerator, defrosting freezed drain water and a manufacturing method thereof. <P>SOLUTION: In this refrigerator, a refrigerant is circulated through an internal piping 24c of an evaporator 24a to cool the interior of a cold reserving box 4, and hot gas is circulated through the internal piping to defrost the evaporator. In the refrigerator, further the lower surface of the evaporator is provided with a drain pan 24j for catching the drain water generated in defrosting, a drain hose 24g discharging the drain water caught by the drain pan to the outside of the cold reserving box and a frozen drain water defrosting pipe 28bx disposed in the drain to circulate the hot gas. In the refrigerator, the defrosting pipe 28bx is integrated with the evaporator 24a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a refrigeration apparatus including an evaporator mounted on a refrigeration vehicle or the like, and more particularly, to an inexpensive refrigeration apparatus that discharges drain water generated at the time of defrosting the evaporator to the outside of the cold storage.

  In general, a refrigeration apparatus is configured by sequentially connecting, for example, a compressor, a condenser, a decompression unit, and an evaporator (evaporator) by refrigerant piping, and an evaporator is disposed in a cool box, and the inside of the cool box through the evaporator. The inside of the cool box is cooled by supplying air from the fan. In such a refrigeration apparatus, the refrigerant gas discharged from the compressor is liquefied by the condenser, then sent from the decompression means (expansion valve) to the evaporator, gasified by the evaporator, and then sent to the compressor. It is supposed to be returned.

  In the refrigeration apparatus, the evaporator is defrosted because frost adheres to the evaporator due to intrusion of outside air into the cool box or moisture generated from the object to be frozen, and the cooling power is reduced. There is a need.

  Therefore, a defrost operation is performed in which high-temperature and high-pressure hot gas discharged from the compressor is periodically guided to the evaporator via a bypass path by a timer or the like, and frost adhering to the evaporator is thawed (defrosting by a hot gas method). Conventionally, a defrosting apparatus which is made to perform has been used.

  By the way, when the evaporator is defrosted by the defrost device, the drain water generated at the time of defrosting is received by the drain pan provided on the lower surface of the evaporator, and then discharged to the outside of the cold storage by the drain hose. It has become.

  However, since the drain pan and the drain hose are cooled to a temperature similar to the temperature in the cool box, the drain water is frozen on the drain pan and in the drain hose, and the drain water cannot be discharged outside the cool box.

  Therefore, a coil heater is installed on the drain pan (Patent Document 1), or a part of the bypass path through which hot gas passes is formed in a U-shape (freezing drain water thawing pipe) (Patent Document 2). ) Has been proposed. This makes it possible to thaw and drain the drain water frozen by the heat of the coil heater or hot gas.

JP-A-4-263379 JP 2003-207257 A

  However, the above proposal has a problem in terms of cost because a coil heater is required separately, or a configuration in which a part of the bypass path is fixed to the drain pan using a bracket or the like is complicated. Below, the structure fixed using a bracket etc. is demonstrated in detail.

  FIG. 7 shows a conventional evaporator unit 924 (evaporator), in which a part of the bypass path is fixed to the drain pan using a bracket or the like. 924a is an evaporator, 924b is an evaporator fan, 924c is an evaporator internal pipe, 924d is a fin, 924e is a plate for fixing the internal pipe 924c, 924j is a drain pan, 924k is a bracket for fixing the thawing pipe 928b to the drain pan 924j It is. The drain pan 924j is separate from the evaporator case main body 924x and is riveted to the case main body 924x.

  As shown in FIG. 7, the refrigeration apparatus according to the prior art has a complicated structure and is expensive due to the necessity of the fixing bracket 924k and the necessity of fixing the thawing tube 928b to the drain pan 924j. It was a cost.

  This invention is made | formed in view of this point, The place made into the objective is to provide the low-cost refrigeration apparatus which can defrost the frozen drain water, and its manufacturing method.

The present invention provides a refrigeration apparatus and a method for manufacturing the same according to the claims as means for solving the problems.
According to the invention described in claim 1, the refrigeration apparatus is characterized in that the thawing tube is integrated with the evaporator. This eliminates the need for a conventional coil heater or a separate thawing tube, and provides an inexpensive refrigeration apparatus.

  According to the invention described in claim 2, the refrigeration apparatus is characterized in that the internal pipe and the thawing pipe are fixed to the same fin. Since the fin is also connected to the thawing pipe, the thawing pipe is securely fixed to the evaporator and can withstand engine vibration.

  According to the third aspect of the present invention, in the method for manufacturing a refrigeration apparatus, an internal pipe and a thawing pipe are inserted and positioned in a hole of one plate, and the internal pipe and the thawing pipe are mechanically expanded. It is characterized by expanding and fixing at the same time. This method makes it possible to manufacture an efficient refrigeration apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of a refrigeration vehicle to which a refrigeration apparatus according to an embodiment of the present invention is applied. FIG. 2 is a refrigerant circuit diagram showing a refrigerant circulation system of the refrigeration apparatus.

  In FIG. 1, reference numeral 1 denotes a refrigeration vehicle. The refrigeration vehicle 1 includes a refrigeration device 2 and is configured to cool the inside of a cold storage 4 mounted on the vehicle 3.

  As shown in FIG. 2, the refrigeration apparatus 2 decompresses the refrigerant 21 compressed by the compressor 21, the condenser unit 22 that condenses the refrigerant compressed by the compressor 21, and the refrigerant condensed by the condenser unit 22. The decompression unit 23 and an evaporator unit 24 (evaporator) for evaporating the refrigerant decompressed by the decompression unit 23 are sequentially connected by a refrigerant pipe 25, and the evaporator unit 24 is installed in the cool box 4 of the refrigerator 1. It arrange | positions and it is comprised so that the inside of the cool box 4 may be cooled.

  The compressor 21 is driven by an oil discharge capacity from an oil pump 12 that is driven together with an auxiliary device (not shown) via a belt 11 with respect to an output shaft of an engine (not shown). As shown in FIG. 1, the compressor 21 is accommodated in a power unit box 20 attached to the lower surface of the cool box 4.

  The capacitor unit 22 is attached to the lower surface of the cool box 4 in front of the power unit box 20. The capacitor unit 22 includes a capacitor 22a and a capacitor fan 22b. The refrigerant compressed by the compressor 21 is condensed by releasing heat to the air sent by the condenser fan 22b in the condenser 22a.

  The decompression unit 23 includes two sets of heat exchange units 26 and 27 and decompression means 23a for decompressing the refrigerant. The two heat exchange units 26 and 27 are connected in series to the capacitor unit 22 via the refrigerant pipe 25. The heat exchange unit 26 located on the upstream side includes a gas-liquid separator 26a that gas-liquid separates the refrigerant condensed by the capacitor unit 22 into a gaseous refrigerant and a liquid refrigerant, and a gas separated by the gas-liquid separator 26a. And a heat exchanger 26c for exchanging heat between the gaseous refrigerant decompressed by the decompressing means 26b and the liquid refrigerant separated by the gas-liquid separator 26a. The heat exchange unit 27 located on the downstream side also separates the liquid refrigerant heat-exchanged by the heat exchanger 26c of the heat exchange unit 26 on the upstream side into a gaseous refrigerant and a liquid refrigerant again. And a pressure reducing means 27b for depressurizing the gaseous refrigerant separated by the gas-liquid separator 27a, and a heat exchange between the gaseous refrigerant decompressed by the pressure reducing means 27b and the liquid refrigerant separated by the gas-liquid separator 27a. And a heat exchanger 27c to be operated.

  The evaporator unit 24 is attached to the upper part of the front wall in the cool box 4. The evaporator unit 24 includes an evaporator 24a and an evaporator fan 24b. The other end of the refrigerant pipe 25 having one end connected to the heat exchanger 27c of the downstream heat exchange unit 27 of the decompression unit 23 is connected to the inlet side of the internal pipe 24c of the evaporator 24a, while the evaporator 24a The other end of the refrigerant pipe 25 having one end connected to the suction port side of the compressor 21 is connected to the outlet side of the internal pipe 24c.

  And the liquid refrigerant heat-exchanged by the heat exchanger 27c of the downstream heat exchange unit 27 of the decompression unit 23 is heat-exchanged with the air in the cool box 4 sucked from the duct by the evaporator fan 24b in the evaporator 24a. Thus, the heat of the air is absorbed and evaporated to return to the compressor 21 as a complete gaseous refrigerant. In this way, the heat of the air in the cool box 4 absorbed by the evaporator 24a is radiated to the air outside the cool box 4 by the heat exchangers 26c and 27c and the condenser 22a, and heat exchange with the evaporator 24a is performed. The air in the cool box 4 in which heat is absorbed is blown out into the cool box 4 so that the temperature in the cool box 4 can be lowered.

  Further, the refrigeration apparatus 2 includes a defrost apparatus 28 that performs a defrost operation by directly supplying a high-temperature refrigerant compressed by the compressor 21 into the internal pipe 24c of the evaporator 24a. The defrost device 28 includes a bypass pipe 28b as a pipe directly connecting the refrigerant pipe 25 between the compressor 21 and the condenser 22 and the inlet side of the internal pipe 24c of the evaporator 24a, and in the middle of the bypass pipe 28b. And an electromagnetic valve 28a for opening and closing the bypass pipe 28b. When the electromagnetic valve 28a is opened, the evaporator 24a is heated by directly supplying the high-temperature refrigerant compressed by the compressor 21 into the internal pipe 24c of the evaporator 24a via the bypass pipe 28b. Defrosting (defrosting operation) of frost adhering to the internal pipe 24c and the fin 24d is performed. In the defrosting operation (defrosting operation), the control device 5 that controls the refrigeration device 2 controls the start timing and end timing thereof.

(First embodiment)
FIG. 3 is a sectional view of the evaporator unit according to the first embodiment of the present invention. Fig.4 (a) is a side view of the evaporator which concerns on 1st Embodiment, (b) is a figure which shows the XX cross section in Fig.4 (a).

  As shown in FIG. 3, the evaporator unit 24 is provided with an evaporator 24a, a fan 24b, and an evaporator case 24x surrounding them. On the lower surface of the evaporator unit 24, a tray-shaped drain pan 24j that receives drain water generated during defrosting by the defrost device, and an upper end of the drain pan 24j connected to the lower end of the drain pan 24j, the drain water received by the drain pan 24j 4 is provided with a drain hose 24g that discharges outside. The drain pan 24j is separate from the evaporator case main body 24x and is riveted to the case main body 924x.

  In FIG. 4, 24 c is an evaporator internal pipe (hereinafter simply referred to as “internal pipe”), and the refrigerant passes through the inside during cooling, and the hot gas passes through the inside during defrosting. In FIG. 4 (b), 30 lines in 5 rows and 6 columns from the upper side are internal pipes 24c. Although omitted in FIG. 4, the adjacent internal pipes 24 c are connected to each other via a brazed U-shaped pipe (not shown). 24d is a fin, and 24e is a plate for fixing the internal pipe 24c and a frozen drain water thawing pipe 28bx described later. A total of three plates 24e are provided on both sides and in the middle.

  And the arrangement | positioning part in the drain pan of the bypass pipe 28b has the function to defrost the drain water frozen by the hot gas passing through the inside. For this reason, in this specification, the arrangement | positioning part in the drain pan of the bypass pipe 28b shall be called the frozen drain water thawing pipe 28bx. In FIG. 4B, the lower five are defrosting tubes 28bx. The frozen drain water thawing pipe 28bx is formed in a plurality of U shapes in plan view along the bottom surface of the drain pan 24j. (In FIG. 4, the U-shaped tube portion is omitted for simplification.) The frozen drain water thawing tube 28bx does not allow the refrigerant to pass through it during cooling.

  In the first embodiment, the fin 24d is not connected to the thawing tube 28bx. Since the thawing tube 28bx is disposed in the drain pan, when the fin is connected to the thawing tube 28bx, the fin is also disposed in the drain pan. In this case, there is a possibility that the fins are deformed when the drain water stored in the drain pan freezes. In order to prevent this, the fin 24d is not connected to the thawing tube 28bx.

(Second Embodiment)
However, for example, it is possible to prevent the deformation of the fin by setting the fin thickness to a certain value or more. Therefore, by expanding the area of the fin 24d, the thawing pipe 28bx is also similar to the internal pipe 24c. It is also possible to fix to (see FIG. 5). That is, the internal pipe and the thawing pipe are fixed to the same fin. In this case, since the fin is also connected to the thawing pipe, the thawing pipe is firmly fixed to the evaporator and can withstand engine vibration.

(Production method)
Next, the manufacturing method according to the present invention will be described with reference to FIG. H is a so-called expander. The outer diameter D2 of the expander H is slightly larger than the pipe inner diameter D1 on the counterpart side. Here, the manufacturing process of the evaporator 24a will be described with reference to FIG.

  First, the internal pipe 24c and the thawing pipe 28bx are inserted into the pipe fixing holes arranged in the three plates 24e and the numerous fins 24d, and positioned and temporarily fixed. Next, as shown in FIG. 6, a set of expansion tubes H is simultaneously inserted into the internal piping 24c and the thawing tube 28bx. The inner diameter D1 of the internal pipe 24c and the thawing pipe 28bx is slightly enlarged by the pipe expander H, and the pipe is friction-welded and fixed to the other three plates 24e and a large number of fins 24d. This is called the mechanical pipe expansion method.

  Finally, molten “wax” is poured between the internal pipe 24c and the thawing pipe 28bx, and the three plate 24e and the pipe fixing holes of the numerous fins 24d. By cooling and solidifying the wax, the internal pipe 24c and the thawing pipe 28bx are securely fixed to the three plates 24e and the numerous fins 24d.

  Conventionally, at the time of manufacturing the evaporator, only the internal piping is fixed to the plate and fin by the above method. In the present invention, the thawing tube is also fixed in the same manner. That is, since the number of pipes to be fixed is merely increased, the manufacturing cost is almost the same, and the cost does not increase. This means that the cost is reduced by the manufacturing cost for fixing the conventional thawing tube.

  In addition, this invention is not limited to the said embodiment, Other various modifications are included. For example, in the above-described embodiment, the case where the cold storage box of the freezer is applied to a refrigeration apparatus for freezing is described. However, the present invention can be applied to a refrigeration apparatus such as a refrigeration container or a stationary type freezer.

It is a perspective view which shows schematic structure of the freezing vehicle provided with the freezing apparatus which concerns on this invention. It is a refrigerant circuit figure which shows the refrigerant | coolant circulation system of a freezing apparatus. It is sectional drawing of the evaporator unit which concerns on 1st Embodiment of this invention. (A) is a side view of the evaporator which concerns on 1st Embodiment of this invention, (b) is a figure which shows the XX cross section in Fig.4 (a). It is sectional drawing of the evaporator unit which concerns on 2nd Embodiment of this invention. It is explanatory drawing of the manufacturing method which concerns on this invention. It is sectional drawing of the conventional evaporator unit.

Explanation of symbols

24a Evaporator 28bx Freezing drain water thaw tube

Claims (3)

A refrigerating apparatus that cools the inside of the cool box (4) by circulating a refrigerant in the internal pipe (24c) of the evaporator (24a) and defrosts the evaporator by circulating hot gas in the internal pipe. There,
Furthermore, a drain pan (24j) for receiving drain water generated at the time of defrosting, a drain hose (24g) for discharging the drain water received by the drain pan to the outside of the cold storage chamber, A frozen drain water thawing pipe (28bx) through which the hot gas is circulated,
The refrigeration apparatus (2), wherein the thawing pipe (28bx) is integrated with the evaporator (24a).   The refrigeration apparatus (2) according to claim 1, wherein the internal pipe (24c) and the thawing pipe (28bx) are fixed to the same fin (24d).   The refrigeration apparatus according to claim 1 or 2, wherein the internal pipe (24c) and the thawing pipe (28bx) are inserted and positioned in a pipe fixing hole of one plate (24e), and the internal pipe and the A production method characterized in that the thawing pipe is expanded and fixed simultaneously by a mechanical pipe expansion method.

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