CN204063689U - A kind of unit auto-cascade refrigeration free convection air-cooled condenser - Google Patents

Abstract

The utility model provides a natural convection air-cooled condenser for single-unit self-cascading refrigeration, which includes an S-shaped rotary liquid pipe, and is characterized in that: the liquid pipe includes an inclined pipe with a slope greater than 4° along the flow direction, The preferred slope of the inclined pipe is 6°-8°. The liquid pipe in the middle part of the air-cooled condenser is branched downwards from one pipe to form two branch pipes. It facilitates the timely discharge of the liquid film of the working medium and the frozen oil film, reduces the thickness of the boundary layer, thereby increasing the heat transfer coefficient; on the other hand, optimizes the heat exchange conditions between steam and liquid, and greatly improves the condensation effect. The structure is simple, the processing is convenient, the production cost is low, and it is convenient to popularize and apply.

Description

A natural convection air-cooled condenser for self-cascading refrigeration

technical field

The utility model belongs to the technical field of thermal equipment and relates to the improvement of heat exchanger technology, in particular to a natural convection air-cooled condenser for single-unit self-cascading refrigeration.

Background technique

Air-cooled condensers are widely used in household refrigeration appliances, household air-conditioning appliances, industrial and commercial refrigeration and air-conditioning equipment. The air-cooled condenser uses air as the heat exchange medium for heat exchange, and the heat is taken away by the air, so it is also called an air cooler. Generally speaking, the heat dissipation effect of the air cooler mainly depends on the heat exchange area and air volume of its component radiator. For the same heat exchange area, the larger the air volume, the better the heat dissipation effect. The same air volume, the larger the heat exchange area, and the better the heat dissipation The better the effect. In the existing natural convection air-cooled condenser, the steam enters from the upper part, and the liquid flows out from the lower part, and the serpentine liquid pipes are parallel to each other. The annular flow shown in Figure 3 is the flow pattern of the existing natural convection air-cooled condenser in the middle position. From this point of view, the existing natural convection air-cooled condenser has large flow resistance and poor condensation effect at the outlet. problem, it is necessary to further strengthen the heat transfer.

Due to the single-unit self-cascade refrigeration, the heat transfer coefficient of the non-azeotropic mixture is lower than that of a single working medium. How to improve the structure of the air-cooled condenser to facilitate the timely discharge of the liquid working fluid film and the frozen oil film, reduce the thickness of the boundary layer, thereby greatly improving the heat transfer coefficient; on the other hand, make the exchange of steam and liquid Thermal conditions are optimized to greatly improve the condensation effect, which is an urgent problem to be solved in this technical field.

Contents of the invention

In order to solve the above-mentioned problems in the prior art, the utility model provides a natural convection air-cooled condenser for single-unit self-cascading refrigeration, which facilitates the timely discharge of the liquid film of the liquid working medium and the liquid film of the frozen oil, and reduces the loss of the boundary layer. Thickness, so as to improve the heat transfer coefficient; on the other hand, optimize the heat transfer conditions between steam and liquid, and greatly improve the condensation effect.

The purpose of this utility model is achieved through the following technical solutions: a natural convection air-cooled condenser for single-unit self-cascading refrigeration, including an S-shaped rotary liquid pipe, characterized in that the liquid pipe contains Inclined tubes with a slope greater than 4°.

Preferably, the slope of the inclined pipe is 6°-8°.

A further improvement to the above technical solution: the liquid pipe in the middle part of the air-cooled condenser is branched downwards from one pipe to become two branch pipes.

A further improvement to the above technical solution: the two branch pipes are parallel to each other, and the two branch pipes also include inclined branch pipes with a slope greater than 4° along the flow direction.

Preferably, the slope of the inclined branch pipe is 6°-8°.

Compared with the prior art, the utility model has many advantages and positive effects:

1. The liquid pipe in the natural convection air-cooled condenser for stand-alone self-cascading refrigeration of the present invention includes an inclined pipe with a slope greater than 4° along the flow direction. When the compressor stops, the oil film and liquid film on the inner wall of the pipe can automatically Flow to the outlet of the condenser; when the compressor is turned on, the oil and liquid film can flow to the outlet of the condenser faster with the flowing working medium, which is convenient for the liquid film of the working medium and the frozen oil to be discharged in time, reducing the adhesion surface The thickness of the layer can reduce the thermal resistance and greatly improve the heat transfer coefficient;

2. In the utility model, the liquid pipe in the middle part of the air-cooled condenser is bifurcated downwards from one pipe to form two branch pipes, and the flow pattern in the middle position of the natural convection air-cooled condenser becomes a stratified flow, and the mixed steam and the wall surface Direct contact eliminates the resistance of the fluid boundary layer to heat transfer, which is more conducive to condensation heat transfer, optimizes the heat transfer conditions between steam and liquid, and greatly improves the condensation effect;

3. The utility model has the advantages of simple structure, convenient processing, low production cost, and is convenient for popularization and application.

Description of drawings

Fig. 1 is the structural diagram of the natural convection air-cooled condenser for self-cascading refrigeration of the utility model;

Fig. 2 is the schematic diagram of the flow pattern in the middle position of the natural convection air-cooled condenser for self-cascading refrigeration of the utility model;

Fig. 3 is a schematic diagram of the flow pattern in the middle position of the existing natural convection air-cooled condenser.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described.

Referring to Fig. 1 and Fig. 2, an embodiment of a natural convection air-cooled condenser for stand-alone self-cascading refrigeration of the present invention includes an S-shaped rotary liquid pipe 1, and the upper left end of the liquid pipe 1 is a steam inlet 1-1 , the liquid pipe 1 includes an inclined pipe with a slope greater than 4° along the flow direction, and the preferred slope of the inclined pipe is 6-8°. When the slope of the inclined tube is ≥ 4%, the oil film and liquid film on the inner wall of the tube can automatically flow to the outlet of the condenser when the compressor stops; Condenser outlet, thereby reducing thermal resistance and greatly improving heat transfer coefficient.

The liquid 1 in the middle part of the air-cooled condenser is bifurcated downwards from a pipe to form two branch pipes. The two branch pipes are respectively called the first branch pipe 2 and the second branch pipe 3. The first branch pipe 2 and the second branch pipe 3 are parallel to each other. , and both the first branch pipe 2 and the second branch pipe 3 also include inclined branch pipes with a slope greater than 4° along the flow direction, and the preferred slope of the inclined branch pipes is 6°-8°. The lower left ends of the first branch pipe 2 and the second branch pipe 3 are respectively a liquid discharge port 2-1 and a liquid discharge port 3-1.

As shown in Figure 2, the natural convection air-cooled condenser of the utility model has a stratified flow pattern in the middle position, so that the mixed steam directly contacts the wall of the liquid pipe, and the hindrance of the fluid boundary layer to heat exchange is eradicated , which is more conducive to condensation heat transfer.

Of course, the above description is not intended to limit the present utility model, and the present utility model is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the art within the essential scope of the present utility model shall also belong to the protection scope of the present utility model.

Claims (6)

1. A natural convection air-cooled condenser for single-unit self-cascading refrigeration, comprising an S-shaped rotary liquid pipe, characterized in that, the liquid pipe includes an inclined pipe with a slope greater than 4° along the flow direction. 2. The natural convection air-cooled condenser for single-unit self-cascading refrigeration according to claim 1, wherein the slope of the inclined tube is 6°-8°. 3. The natural convection air-cooled condenser for single-unit self-cascading refrigeration according to claim 1 or 2, wherein the liquid pipe in the middle part of the air-cooled condenser is bifurcated downwards from one pipe to form two root branch. 4. The natural convection air-cooled condenser for single-unit self-cascading refrigeration according to claim 1 or 2, wherein the two branch pipes are parallel to each other, and the two branch pipes also include a gradient greater than 4 along the flow direction. ° inclined branch pipe. 5. According to the natural convection air-cooled condenser for single-unit self-cascading refrigeration according to claim 3, it is characterized in that, the two branch pipes are parallel to each other, and the two branch pipes also include a gradient greater than 4° along the flow direction. Slope branch. 6. The natural convection air-cooled condenser for single-unit self-cascading refrigeration according to claim 5, wherein the slope of the inclined branch pipe is 6°-8°.