CN1313787C - Evaporator for a refrigeration device - Google Patents

Abstract

The evaporator for a refrigeration device is provided with a hydrophobic coating on the surface thereof, in order to inhibit the icing of the evaporator during operation and to reduce the generation of noises arising from relative displacements between the evaporator (4) and the ice (3) attached thereto.

Description

Evaporators for refrigeration equipment

technical field

The invention relates to an evaporator for refrigeration equipment.

Background technique

The surface temperature of such evaporators can reach below 0°C when refrigerant is supplied. Air moisture from the interior of the refrigeration unit can thus condense and freeze on the evaporator surfaces. Among them, a thin layer of evenly distributed frost layer is first formed on the surface of the evaporator. If the frost layer is not melted during this period, it will continue to thicken with the operation of the refrigeration equipment, and finally gather into firm and hard ice. layer. Because the temperature of the evaporator varies with time, depending on whether it is being supplied with refrigerant, the ice sheet will periodically expand and re-contract over time. Tension builds up between the ice and the evaporator below it, eventually causing the ice to slide off in pulses. The resulting click noise is disturbing.

Contents of the invention

The object of the present invention is to design an evaporator for a refrigeration appliance in which the rattling noise is reduced.

This object is solved in that a hydrophobic coating is provided on the surface of the evaporator on which ice may be formed.

According to the invention, there is provided an evaporator for a refrigerating device, having a pipe for refrigerant and a surface which is thermally conductively connected to the pipe and serves as a heat exchange surface, wherein at least one The surface of the hot side is provided with a hydrophobic oil layer.

Such a coating serves to delay the formation of the first layer of ice crystallization on an ice-free evaporator and thus prolongs the time required until ice masses accumulate on the evaporator after the melting process, which is sufficient to cause a clicking noise. Another function of the hydrophobic coating is to prevent the formation of a uniform frost layer on the surface of the evaporator. Instead, an unavoidable small amount of ice forms on the evaporator surface. The ice beads that form there grow roughly evenly over the surface on which they collect and reach a considerable thickness before they begin to collect. That is, on an evaporator according to the present invention a large number of ice masses can accumulate on an evaporator according to the invention, compared to an evaporator without a hydrophobic coating, before the formation of a relevant layer of ice that would cause a clicking noise.

Another advantage of the isolated growth of the ice layer is that a certain area on the surface of the evaporator can remain ice-free for a relatively long time, and thus effective heat exchange can be carried out between the refrigeration equipment and the environment. Other areas have accumulated considerable amounts of ice. The time interval between two thawing processes can thus be prolonged compared to that in evaporators without a hydrophobic coating, which increases comfort and reduces energy consumption for users of refrigeration equipment equipped with evaporators according to the invention. Consumption and the resulting production costs.

The hydrophobic coating can preferably be silicone resin as the component that produces the hydrophobic effect.

The coating can be applied as a layer of cured lacquer or oil. Among them, the oil layer is particularly advantageous, because the oil itself is not solid, so it promotes the mobility of the ice beads formed on the surface of the evaporator, and also makes the evaporator have a certain layer thickness when it is completely frozen, which is in the traditional evaporator. The rattling noise is sufficient to generate the rattling noise, but it is reduced in the evaporator according to the invention, because it is not necessary to generate a strong thermal tension causing a loud rattling noise to cause the relative movement between the ice shell and the evaporator, and generally a small tension It is sufficient to allow the ice sheet to slide off the evaporator, or possibly even achieve a continuous slide of the ice sheet over the evaporator.

The evaporator according to the present invention is preferably designed as a plate evaporator, which is suitable for use in air-cooled refrigeration equipment or refrigeration equipment.

Description of drawings

The accompanying drawing shows a schematic diagram of a plate evaporator 4 according to the invention when it is partially frozen.

Detailed ways

The plate evaporator 4 includes a pipe 1 for the refrigerant to flow through. A sheet 2 is wound helically around the outer surface of the pipe 1 . The surface of the sheet 2 constitutes one heat exchange surface, while the outer surface of the pipe 1 on which the sheet 2 is mounted forms another heat exchange surface. These heat exchange surfaces of the plate evaporator are provided with a hydrophobic coating made of silicone oil.

Due to the hydrophobic nature of the coating, a lot of energy is required to wet the surface of the plate evaporator 4, and this energy must be released when the liquid freezes on the surface. This is a great obstacle to reforming ice beads on the surface. Therefore, when the moisture in the air flow is supersaturated, a considerable part of the moisture in the air flow passing through the plate evaporator will not condense on the plate evaporator 4 by itself, and it is only because the moisture does not encounter energy. Good for icy surfaces. Therefore, when the plate evaporator is installed in air-cooled refrigeration equipment or frost-free refrigeration equipment, the air in the inner chamber of the refrigeration equipment can only produce a small amount of drying, which is ideal for storing sensitive foods such as some fresh vegetables. Totally worth pursuing.

In order for the air moisture to condense on the plate evaporator, there must be a surface area on which the condensation is energetically favorable. Most condensation origins appear as areas of dust particles, surface interruptions or the like, which are unavoidably present on the surface of plate evaporators, but only form in a small part. At these condensation points—as shown in FIG. 1—a large number of small ice beads 3 form during operation of the plate evaporator. Moisture in the air surrounding the sheet evaporator 4 continues to condense preferentially on the surface of these ice beads 3, so that the ice beads 3 increase in thickness and diameter over time, while the evaporator 4 surface remains for a long time in some areas between the ice beads There is no ice, and effective heat exchange can be performed between the refrigerant circulating in the plate evaporator 4 and the surrounding air.

Claims (3)

1. the evaporimeter that is used for refrigeration plant, have that a pipeline (1) that is used for cold-producing medium can be connected with pipeline (1) with heat conduction with one and as the surface of a heat-transfer surface, it is characterized in that the surface as a described heat-transfer surface is provided with the hydrophobic oil reservoir of one deck at least.

2. evaporimeter according to claim 1 is characterized in that, the outer surface of described pipeline (1) is used as another heat-transfer surface, and is provided with the hydrophobic oil reservoir of one deck.

3. evaporimeter according to claim 1 and 2 is characterized in that, it is a plate evaporator (4).

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