JPH05133644A - Evaporator for refrigerator - Google Patents

Abstract

PURPOSE:To obtain an evaporator for a refrigerator in which a time to an end of defrosting can be shortened and a sensor for sensing the end of defrosting can be reduced. CONSTITUTION:A plate-fin type evaporator 18 is formed of three front and rear rows of refrigerant tubes and a plurality of plate fins. Refrigerant tubes 10 of a front row to communicate with an inlet 13 of refrigerant are disposed in zigzag from below to above. Refrigerant tubes 11 of an intermediate row are disposed in zigzag from above to below. Refrigerant tubes 12 of a rear row are disposed in zigzag from below to above. An outlet 14 of the refrigerant is provided at an upper part. The tubes are connected in this order. A sensor 17 for sensing the end of defrosting is disposed near the outlet, and a defrosting glass tube heater 15 is disposed under the evaporator 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of an evaporator of a refrigerator such as a large refrigerator.

[0002]

2. Description of the Related Art A heat exchanger (evaporator) in a conventional air conditioner of this type has a plurality of plate fins 1 arranged in parallel as shown in JP-A-3-105197 and FIG. A plurality of refrigerant pipes 4 formed in a hairpin shape are arranged in rows and straddle the front rows 2 and the rear rows 3 of the plate fins 1 so as to be in close contact therewith. Also, the plurality of U-shaped tubes 5 are brazed all around for each refrigerant tube so that the tube end 6a of one refrigerant tube 4a and the tube end 6b of the other refrigerant tube 4b communicate with each other among the plurality of refrigerant tubes 4. An inlet pipe end 7 fixed by 5a and serving as an inlet for the refrigerant
A flow path is formed in a so-called meandering shape from the outlet pipe end 8 serving as an outlet of the refrigerant. With the above configuration, the refrigerant flows in through the inlet pipe end 7, passes through the flow path formed by the plurality of refrigerant pipes 4 and the plurality of U-shaped pipes 5, and flows out through the outlet pipe end 8. During this time, the heat of the refrigerant is transferred from the plurality of refrigerant tubes 4 to the multiple parallel plate fins 1 and is exchanged with the air passing between the multiple parallel plate fins 1. there were.

[0003]

By the way, as described above, in the prior art, the refrigerant inlet portion is arranged above the refrigerant pipe in the front row, and the refrigerant outlet portion is arranged below the refrigerant pipe in the front row. A header (not shown) was arranged in the vicinity of. On the other hand, in a domestic refrigerator, it is customary to provide a defrosting glass tube heater (not shown) below the refrigerant tube, and the liquid refrigerant is always present at the refrigerant inlet. Since it takes time for the warm air from the heater to transfer heat to the upper refrigerant inlet despite the large amount of frost formed at the inlet, defrosting at the inlet tends to be the most delayed. In addition, the sensor that detects the end of defrost is usually installed in the part where defrost is likely to be delayed in order to prevent residual frost. In addition to the inlet where frost is likely to occur, it is also installed to keep the residual liquid in the refrigerant. The defrosting is delayed in the header part where the refrigerant liquid stays and the defrosting is delayed. Therefore, the sensor installed in the inlet part cannot predict the defrosting end time of the header part, and the sensors are installed in both the inlet part and the header part. There was a need.
Further, since the defrosting operation continues until both sensors detect the end of defrosting, there is a problem that the defrosting time becomes long. It is an object of the present invention to provide an evaporator for a refrigerator which solves the above-mentioned problems (problems) of the conventional one.

[0004]

SUMMARY OF THE INVENTION The present invention is an evaporator comprising a plurality of plate fins arranged at predetermined intervals and a refrigerant pipe penetrating these plate fins, and an evaporator arranged below the evaporator. In a refrigerator provided with a frost heater, the refrigerant pipes are arranged in three rows in the front and rear direction, have a refrigerant inlet, and have a front row of refrigerant tubes that meander from bottom to top and a middle row that meander from top to bottom. Is connected to the refrigerant pipe in the rear row which meanders from the lower part to the upper part and has a refrigerant outlet in this order, and a sensor for detecting the end of defrosting by the heater is provided in the vicinity of the refrigerant outlet. Refrigerator evaporator.

[0005]

In the present invention, since the inlet of the refrigerant is brought to the lower side, in the case where there is a frost that is biased near the inlet where frost is easily formed, this inlet is near the glass tube heater. Therefore, it is unlikely that it will be the latest part of defrosting completion and that the vicinity of the inlet will not be the latest part of defrosting completion even under conditions where frost forms on the entire upper and lower sides of the refrigerant pipe. Moreover, stable defrosting completion can be detected by providing only one detection sensor only near the refrigerant outlet, which is likely to be the latest part.
The defrosting time can also be shortened.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to an embodiment shown in FIGS. 1 and 2 are a front view and a perspective view, respectively, showing an embodiment of the present invention, and FIG. 3 is a perspective view showing a refrigerant pipe in each row in an exploded manner in order to explain the flow of the refrigerant. In each figure, reference numerals 10, 11 and 12 denote refrigerant tubes in the front row, middle row and rear row, respectively, which penetrate a plurality of plate fins arranged at intervals. Reference numeral 13 is a refrigerant inlet, 14 is an outlet, and 15 is a header. As shown in FIG. 3, each of the refrigerant tubes 10, 11 and 12 has a plurality of rows of the refrigerant tubes 10 in the front row, which communicate with the refrigerant inlet 13 and meander from the lower portion to the upper portion. The refrigerant pipe 12 communicates with the upper end of the pipe 10 and meanders from the upper part to the lower part. Further, the refrigerant pipe 12 in the rear row communicates with the lower end of the refrigerant pipe 11 in the middle row and meanders from the lower part to the upper part, while its upper end It is connected to the outlet 14 and constitutes an evaporator 18. The outlet 14 is connected to the header 15,
A glass tube heater 16 for defrosting is arranged below the evaporator 18, and a sensor 17 for detecting the end of defrosting is arranged near the refrigerant outlet 14 of the evaporator 18.

In the above structure, the refrigerant flows in through the inflow port 13, and as shown in FIG. 3, the refrigerant tubes 10 in the front row are from below to above, the refrigerant tubes 11 in the middle row are from above to below, and the refrigerant in the back row is shown. The pipe 12 is supplied by a pipe meandering from the lower side to the upper side. In this process, the liquid refrigerant absorbs heat and is converted into vapor, and returns to the compressor (not shown) via the outlet 14 and the header 15. The header 15 separates the gas-liquid two-phase refrigerant so that the liquid refrigerant does not directly return to the compressor.

By the way, in the refrigeration cycle, frost is generated in each part of the evaporator 18, but the portion of the refrigerant inlet 13 where the frost is most likely to form due to the function of the evaporator 18 is a glass tube heater.
Since the heat of the heater 16 is quickly transferred to defrost, the defrosting is not delayed most. After all, since the refrigerant outlet 14 or the header 15 is likely to be the latest portion at the end of defrosting, the sensor 1 that detects the end of defrosting only in the vicinity of the outlet 14.
7 should be provided.

[0009]

As described above, according to the present invention, the refrigerant pipes of the evaporator, in which the defrosting heater is normally arranged below the above-mentioned structure, are constituted by three rows, and the inflow port thereof is downward and the outflow port thereof is upward. Since it is configured to be arranged, it has the following excellent effects. Since a large amount of liquid refrigerant is present and the frost-prone inlet part is closer to the defrosting heater, defrosting at this part is promoted more than the conventional one. The part of is the farthest from the heater, so the defrosting end is the most delayed, but
Since the amount of liquid refrigerant flowing in this portion is easily smaller than the amount of liquid refrigerant at the inlet, the amount of frost is also small. Since defrosting at the inlet with a large amount of frost is promoted and the amount of frost at the outlet can be reduced, the time until the end of defrosting is shortened as a whole compared to the conventional one. Moreover, since one sensor for detecting the end of defrosting may be provided near the refrigerant outlet, the number of parts is reduced. Due to the structure in which the refrigerant rises from the bottom to the top, the refrigerant tubes themselves in each row of the evaporator can have a liquid retaining function. Therefore, the capacity of the header arranged on the downstream side of the evaporator can be made smaller than that of the conventional one.

[Brief description of drawings]

FIG. 1 is a front view showing a configuration of an evaporator which is an embodiment of the present invention.

2 is a perspective view of the embodiment of FIG. 1. FIG.

FIG. 3 is a perspective view showing the refrigerant tubes in each row in a divided manner in order to explain the flow of the refrigerant in the embodiment of FIG.

FIG. 4 is a perspective view showing a configuration of a conventional example.

[Explanation of symbols]

 10: Refrigerant pipe in front row 11: Refrigerant pipe in middle row 12: Refrigerant pipe in rear row 13: Inlet port 14: Outlet port 15: Header 16: Heater for defrost 17: Sensor for detecting completion of defrost 18: Evaporation vessel

Claims (1)

[Claims] 1. An evaporator comprising a plurality of plate fins arranged at a predetermined interval and a refrigerant pipe penetrating the plate fins, and a defrosting heater arranged below the evaporator.
In a refrigerator equipped with a heater, the refrigerant pipes are arranged in three rows in the front and rear direction, have a refrigerant inlet, and have a front row refrigerant tube meandering from bottom to top and a middle row refrigerant tube meandering from top to bottom. A refrigerator characterized by connecting a refrigerant pipe in a rear row, which is meandered from the lower part to the upper part and having a refrigerant outlet in this order, and a sensor for detecting the end of defrosting by the heater is provided in the vicinity of the refrigerant outlet. Evaporator.