JPS5826975A - Method and device for supplying refrigerant to evaporator of 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 The present invention provides a refrigeration system in which the refrigerant liquid evaporates from above inside the evaporator coil and descends under its own weight. - A method and apparatus for supplying refrigerant to an evaporator of a refrigeration system without loss.

In general, in a refrigeration system, it is ideal that refrigerant be supplied to the evaporator evenly to each coil, and that the pressure loss of the refrigerant within the evaporator be as small as possible.

However, the conventional methods of supplying refrigerant to the evaporator include a bottom-feed system that supplies refrigerant through a lower header, a top-feed system that supplies refrigerant through a two-part header, and a system that supplies refrigerant through a double header. There is.

However, in the bottom feed type, the refrigerant liquid rises inside the coil while evaporating, so the pressure of the refrigerant liquid column is applied to a part of the header, and the refrigerant is distributed to each coil evenly to some extent depending on the liquid column pressure. However, there is a drawback that a pressure loss corresponding to the amount of the liquid column occurs. In addition, in the top-feed type, the refrigerant liquid evaporates inside the coil and descends under its own weight, so there is no pressure loss of the refrigerant at all.In fact, in some cases, there may be a negative pressure loss where the pressure is lower in the coil part than in the head part. Tashi. However, in order to equalize the supply of refrigerant to each coil, it is extremely difficult to install the upper header so that each header is in a completely horizontal position, and it is difficult to install the header in a completely horizontal position. Since the flow rate increases, it becomes impossible to uniformly supply refrigerant to each header and each coil.

For this reason, conventionally, as shown in FIG. 6, a fine hole 16 is provided at the base end of the coil in the upper header to apply a slight pressure inside the header to achieve even distribution. However, in this case, although there is no pressure loss within the coil, there is a drawback that the pressure loss in the evaporator including the header becomes large. Furthermore, when supplying by a distributor, the refrigerant liquid is evenly distributed to a large number of thin tubes 18 due to the pressure drop inside the distributor 17, and the thin tubes 18 are connected to the base end of each coil, resulting in a large pressure loss. It has major drawbacks such as the fact that the uniformity of distribution depends on the manufacturing precision of -, and is currently used only in dry evaporators.

As detailed above, conventional refrigerant supply focuses on supplying refrigerant evenly, and a certain amount of pressure loss is accepted, and the method and device for supplying refrigerant to an evaporator for low-temperature cooling are It could not be said to be sufficient. That is, the evaporation pressure of the refrigerant is the saturation pressure at that temperature, and the lower the temperature, the lower the pressure.Therefore, even a small pressure loss will have an extremely large effect on cooling efficiency when the temperature is low. For example, if we want to use Freon 22 as a refrigerant to cool the temperature to -55°C, the refrigerant evaporation temperature is usually sufficient at -62°C, but if we use 0.182 yen (Freon 22) in the evaporator,
If there is a pressure loss of 88σ in the liquid column, the suction gas volume of the compressor will be 1.6 times, and if you add the efficiency of the compressor to this, it will not be possible to cool it unless you use a compressor that is approximately twice the size. It turns out you can't do it.

However, in the present invention, the above-mentioned top feed type device is used, and the base end of each cooling coil is inserted through the lower surface of the pipe of the upper header installed horizontally, and an opening is formed at the base end of the cooling coil. A vertical refrigerant inlet gap is formed at the refrigerant liquid outlet, and the thickness of the cooling coil inserted into the header, the height of the coil base, and the width and height of the gap are made equal to each other, so that the refrigerant liquid inlet The refrigerant liquid that has entered the header accumulates up to the refrigerant liquid outlet at the base end of each cooling coil, and is then supplied to the base end of each coil in the form of overflow, making it possible to distribute it evenly. Furthermore, even if there is some leveling error in the header, the refrigerant is supplied into the coil through the vertical refrigerant inlet gap, so there is no major unevenness. Furthermore, in the present invention, no pressure is applied to the refrigerant liquid, so there is no pressure loss of the refrigerant in the evaporator.

Reference will now be made in detail to the accompanying drawings, which illustrate one example of carrying out the invention. 1 is the upper header of the evaporator 2 of the refrigeration system, and 8 is the refrigerant liquid inlet attached to the central part of the pipe side of the header 1. The refrigerant liquid is supplied by a liquid pump 9.

4 is a cooling coil whose proximal end rises from the lower surface of the pipe of the header 1 and is inserted through a number of holes 5, as shown in FIG.
Pipes of the same diameter are used, and the insertion height of the rising portion 5 of each cooling coil/I/4 into the header 1 is made equal for each cooling coil 4 as shown in FIG. Reference numeral 6 denotes a refrigerant liquid outlet opened at the upper surface of the proximal end of the cooling coil 4 (the tip of the rising part 5), and 7, 7 is a refrigerant liquid outlet opened at the upper surface of the proximal end of the cooling coil 4 (the tip of the rising part 5). In the vertical refrigerant inflow gap,
The thickness of each refrigerant liquid outlet 6 and the width and height of the gap 7.7 are made equal for each cooling coil/I/4. Reference numeral 10 denotes a lower header of the evaporator 2, which is equipped to guide the mixture of refrigerant gas and refrigerant liquid that has descended under its own weight while evaporating inside each coil/V 4 through the refrigerant gas outlet 11 to the low-pressure liquid receiver 8. It is something to do. A refrigerant compressor 12 compresses the refrigerant gas from the low-pressure receiver 8 and supplies high-pressure refrigerant gas to the condenser 18. Reference numeral 14 denotes a liquid receiver for storing the high-pressure refrigerant liquid liquefied by the condenser. Reference numeral 15 denotes an expansion valve interposed between the liquid receiver 14 and the low-pressure liquid receiver i, which converts high-pressure refrigerant liquid into low-pressure refrigerant liquid.

[Brief explanation of the drawing]

The attached drawings show an example of the implementation of the present invention. Figure 1 is a cycle diagram of the apparatus of the present invention using the top feed type, and Figure 2 shows the main points of the joint between the upper header of the evaporator and the cooling coil. Figure 3 is a cross-sectional view of the main part taken along the line A-A in Figure 2, Figure 4 is a perspective view of the main part of a bottom-feed type evaporator, and Figure 6 is a top-feed type upper header and cooling. FIG. 7 is a cross-sectional view of a main part showing a joint part of the coil, and a perspective view of a main part showing an outline of supply by a distributor. 1... Upper header, 2... Evaporator, 8... Refrigerant liquid inlet, 4... Cooling coil, 5... Rising part,
6... Refrigerant liquid outlet, 7... Inflow gap, 8... Low pressure liquid receiver, 9... Liquid pump, 10... Lower header,
11... Refrigerant gas outlet, 12... Refrigerant compressor, 13
...Condenser, 14...Liquid receiver, 15...Expansion valve,
16... Pore, 17... Distributor-11
8...tubule. Applicant: Nichishin Gyogyo Co., Ltd. wJ l Figure 2 Figure 3 m- Figure 5 Figure 6 b Figure 7

Claims (1)

[Scope of Claims] 1. An evaporator for a refrigeration system characterized by equalizing refrigerant distribution conditions from a header to a cooling coil as the refrigerant liquid evaporates from above and descends under its own weight. refrigerant supply method. 2. A header pipe with a refrigerant liquid inlet located slightly above the header pipe is installed horizontally, the base end of the cooling coil is inserted through the bottom surface of the header pipe, and a refrigerant liquid outlet is opened on the top surface of the base end. An inflow gap is bored from the open end, and the thickness and height of the opening of the cooling coils starting from the same header pipe are made equal to each other, and the thickness and height of the gap is made equal to each cooling coil. A refrigerant supply device to an evaporator of a refrigeration system.