JPS61240079A - Evaporator for refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an evaporator for a refrigerator used in a refrigerator or the like.

2. Description of the Related Art A conventional evaporator for a refrigerator used in a refrigerator or the like will be explained with reference to FIGS. 4 and 5. 1 is a fin, and 2 is a cylindrical collar provided on the fin 1. Two collars 2 are arranged linearly on the fin 1. 3 is a refrigerant pipe. The evaporator 4 includes a bent pipe section 5 that bends the fins 2 into a meandering shape of the refrigerant pipe 3.
The fins 2 and the refrigerant pipe 3 are inserted while avoiding the fins 2 and the refrigerant pipe 3 are expanded, and then the refrigerant pipe 3 is bent into a meandering shape. Moreover, it is installed inside a refrigerator or the like so that the airflow inflow side A is at the bottom. A defrosting heater 6 is provided near the bottom of the evaporator 4, and periodically generates heat to defrost the frost adhering to the evaporator 4 using radiant heat.

Problems to be Solved by the Invention However, with such a structure, the evaporator 4 is closed during defrosting.
Since the radiant heat does not reach the top of the evaporator, the temperature at the top of the evaporator is
The temperature at the bottom of the evaporator rises more slowly than the temperature at the bottom of the evaporator, and in order to melt the frost at the top of the evaporator, it is necessary to heat the bottom of the evaporator more than necessary. This was a factor that hindered the development of thinner models.

Therefore, the present invention aims to equalize the temperature of the evaporator during defrosting, shorten the defrosting time, and make the evaporator thinner.

Means for Solving the Problems In order to solve the above problems, the evaporator of the present invention avoids a curved pipe section in which a small piece of fin having one collar into which a refrigerant pipe is inserted is bent into a meandering shape. An evaporator is formed by inserting a refrigerant pipe into a meandering shape, a defrosting heater is provided at the bottom of the evaporator, and an on-off valve that is closed during defrosting is provided in the refrigerant circuit at the inlet and outlet of the evaporator. The evaporator for a refrigerator is constructed using the following methods.

Effect: According to the above-described configuration, the on-off valves at the inlet and outlet of the evaporator are closed during defrosting, so that the evaporator has a single heat pipe, and with the same configuration, the lower part of the evaporator can be defrosted. Since the refrigerant in the evaporator heated by the heater efficiently evaporates up and condenses down in the evaporator, defrosting can be performed in a short time and the temperature rise in the evaporator can be made uniform.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1, 2, and 3. 1o is a fin, and 11 is an elliptical collar provided on the fin 1o. Only one collar 11 is provided approximately at the center of the fin 1o, where the airflow passing through the fin 1o has the highest speed. Reference numeral 12 denotes a refrigerant pipe which has an elliptical cross-sectional shape slightly smaller than the inner diameter of the collar 11 and approximately the same shape so that the fins 1o can be inserted therein. The diameter of the refrigerant pipe 12 is larger than that of a conventional refrigerant pipe. Reference numeral 13 denotes a groove that promotes heat transfer of the refrigerant inside the refrigerant pipe 12 and is provided all around the inner surface of the refrigerant pipe 12 . In the evaporator 14, the fins 1o are inserted avoiding a part of the curved pipe part 16 that bends the fins 1o into a meandering shape and a part of the refrigerant inlet vibe 1e, and the refrigerant pipes 12 are expanded to separate the fins 10 and the refrigerant pipes 12.
After securely fixing the refrigerant pipe 12, the refrigerant pipe 12 is bent into a serpentine shape, which is inclined so that the liquid refrigerant can easily fall, and the airflow inflow side A is at the bottom. It is installed inside the refrigerator. A defrosting heater 17 is a PTC heater having a self-temperature control function. The defrosting heater 17 is fixed by a heater mounting plate 18 so as to be in reliable contact with the inlet vibe 1e at the bottom of the evaporator 14. The upper part of the heater mounting plate 18 has a sealed structure to prevent defrosting water and the like from falling directly onto the heater 17. 19 and 19' are on-off valves that are closed only when the compressor (not shown) is stopped and when defrosting.

In the above configuration, during defrosting, the on-off valves 19 and 19' are first closed. The liquid refrigerant inside the evaporator 14 is
It accumulates in 16 parts of the 0-input vibe.

Next, the liquid refrigerant is heated and evaporated by the defrosting heater 18. An on-off valve 1 is provided at the inlet and outlet of the evaporator 14, respectively.
Since 9.19' is provided and the circuit is closed, the evaporator 14 becomes one heat pipe and the evaporated steam is transferred to the evaporator 14.
By melting the frost attached to the surface of the evaporator 14, it is cooled and condensed into liquid, which flows through the groove 11 on the inner surface of the refrigerant pipe 12 and reaches the inlet vibrator 16 at the bottom of the evaporator 14.
come back to. The liquid refrigerant returns to the defrosting heater 13 again.
It is heated and evaporates. By repeating the above operations, the heat of the defrosting heater 17 installed at the inlet vibrator 1θ at the bottom of the evaporator 14 can be transferred to the top of the evaporator 14 effectively and at high speed. The capacity of the defrosting heater is smaller than that of the defrosting heater, and the defrosting time can be shortened.

Moreover, the defrosting heater 17 has a self-temperature control function.
Since the TC heater is used, it is possible to prevent the temperature of the evaporator 14 from becoming high, thereby reducing the temperature rise inside the refrigerator during defrosting. In addition, by increasing the diameter of the refrigerant pipe and making it an elliptical pipe with grooves, it is possible to not only promote the heat pipe action during defrosting, but also reduce the ventilation resistance of the evaporator 14 during cooling operation, and reduce the air flow inside the refrigerant pipe 12. Since the heat transfer effect is increased, the cooling capacity of the evaporator 12 is not deteriorated.
2 can be made thinner.

Effects of the Invention The present invention provides a method for forming an evaporator by inserting a small piece of fin having a collar into which a refrigerant pipe is inserted, avoiding a bent pipe portion that bends into a meandering shape, and forming an evaporator by forming a meandering shape of the refrigerant pipe. The evaporator is arranged so that the airflow inflow side is at the bottom, a defrosting heater is installed at the bottom of the evaporator, and the refrigerant circuits at the inlet and outlet of the evaporator have on-off valves that are closed during defrosting. During frost, the evaporator does not have the same configuration as a single heat pipe, and the refrigerant in the evaporator heated by the defrosting heater at the bottom of the evaporator efficiently evaporates up and condenses down in the evaporator. Since defrosting can be performed in a short time and the temperature rise of the evaporator can be made uniform, the number of watts of the defrosting heater can be reduced, power can be saved, and a temperature rise in the refrigerator compartment can be prevented during defrosting.

[Brief explanation of drawings]

Fig. 1 is a front view showing the structure of an evaporator according to an embodiment of the present invention, Fig. 2 is a front view of the small piece fin shown in Fig. 1, and Fig. 3 is a front view of the defrosting heater mounting part of Fig. 1. Main part sectional view, Figure 4a,
6b is a front view and a side view of a conventional evaporator, and FIG. 6 is a front view of a single fin in FIG. 4. 1o... Small piece fin, 11... Collar, 12... Refrigerant pipe, 14... Evaporator,
17...Defrosting heater, 19,19'...
・Opening/closing valve. 10---Noj1 MeF Fin 2nd rl! J ↑ No. 3-Groove 17--Defrosting heater 18-1-Heater Mimata Slope 4 Figure i5vl

Claims (3)

[Claims] (1) An evaporator consisting of a meandering refrigerant pipe and a small piece of fin with a collar that is inserted avoiding the meandering part of the refrigerant pipe, and the evaporator is arranged so that the air flow inflow side is at the bottom. An evaporator for a refrigerator comprising: a defrosting heater placed at the bottom of the evaporator; and an on-off valve that closes during defrosting installed in the refrigerant circuit at the inlet and outlet of the evaporator. (2) The evaporator for a refrigerator according to claim 1, wherein the defrosting heater is a self-temperature control type heater. (3) The evaporator for a refrigerator according to claim 1, wherein the refrigerant tube is an elliptical tube with an inner groove.