CN-122029389-A - Direct expansion (DX) refrigerant evaporator with liquid ejector

Abstract

A system and method for increasing the capacity of a direct expansion refrigeration system having an inlet separator and a liquid ejector by increasing the coil liquid refrigerant flow while ensuring that the evaporator outlet flow is liquid free and maintains a small degree of superheat. The increase in liquid refrigerant flow is achieved by partially recirculating liquid from the coil outlet to the coil inlet through an ejector that pumps the non-vaporized liquid refrigerant from a lower pressure (suction pressure) to a higher pressure. The driving force of the ejector is derived from saturated or subcooled liquid after the expansion valve.

Inventors

• S. Gopalan
• G. Drossier

Assignees

• 艾威普科公司

Dates

Publication Date

20260512

Application Date

20240719

Priority Date

20230719

Claims (12)

1. 1. An apparatus for enhancing performance of a direct expansion refrigeration system, comprising: A hydrodynamic ejector having an ejector first liquid inlet, an ejector second liquid inlet, and an ejector liquid outlet; An evaporator having an evaporator inlet and an evaporator outlet; the evaporator outlet has an evaporator outlet liquid outlet and an evaporator outlet vapor outlet; The ejector second liquid inlet is connected to the outlet liquid outlet; the eductor liquid outlet is connected to the dispenser liquid inlet; The outlet vapor outlet is configured to be connected to a compressor.
2. 2. The apparatus of claim 1, wherein the ejector first liquid inlet is configured to be connected to an expansion device.
3. 3. The apparatus of claim 1, further comprising an inlet separator, The inlet separator has an inlet separator inlet, an inlet separator first outlet, and an inlet separator second outlet; The inlet separator first outlet is a liquid outlet, the inlet separator first outlet being connected to the ejector first liquid inlet, the inlet separator inlet being configured to be connected to an expansion device.
4. 4. The apparatus of claim 2, wherein the inlet separator second outlet is a vapor outlet, a vapor inlet connected to the evaporator inlet.
5. 5. The apparatus of claim 2, wherein the inlet separator second outlet is a steam outlet connected to the outlet header or the outlet header steam outlet.
6. 6. The apparatus of claim 2, wherein the inlet separator second outlet is a liquid and vapor outlet, connected to a liquid and vapor inlet of the evaporator inlet.
7. 7. The apparatus of claim 2, wherein the inlet separator is combined with the ejector in an integrated refrigerant recycling device.
8. 8. The apparatus of claim 2, further comprising a heat exchanger connected to the expansion device to deliver cooled refrigerant to the expansion device.
9. 9. The apparatus of claim 2 wherein the evaporator outlet is an outlet header.
10. 10. The apparatus of claim 2, wherein the evaporator outlet is a phase separator.
11. 11. The apparatus of any preceding claim, wherein the evaporator inlet is a distributor.
12. 12. A direct expansion refrigeration system, comprising: -a refrigerant line connecting in sequence: The expansion device is arranged to be connected to the expansion device, An inlet separator, which is provided with a plurality of inlet grooves, A fluid-dynamic ejector of the fluid-dynamic ejector, An evaporator, and A compressor; -the inlet separator is configured to continuously deliver liquid refrigerant to the ejector and simultaneously deliver refrigerant vapor to the evaporator inlet or evaporator outlet; -the hydrodynamic ejector is configured to continuously receive liquid refrigerant from the inlet separator and simultaneously receive liquid refrigerant from the evaporator outlet and deliver liquid refrigerant to the evaporator inlet.

Description

Direct expansion (DX) refrigerant evaporator with liquid ejector Technical Field The present invention relates to direct expansion evaporators in refrigeration systems. Disclosure of Invention One disadvantage of DX evaporator technology compared to pump overfeed systems is that to avoid liquid carry-over and to achieve superheat at the coil outlet, the liquid refrigerant flow through the coil needs to be reduced, resulting in a reduced refrigeration capacity. The invention is an improvement to the existing DX evaporator coil technology, and increases the heat absorption capacity by increasing the flow of liquid refrigerant in the coil, and simultaneously ensuring that the outlet flow of the evaporator is in a liquid-free state and maintains a small amount of superheat. The increase in liquid refrigerant flow is achieved by the ejector partially recirculating the liquid at the coil outlet to the coil inlet. The ejector pumps the non-vaporized liquid refrigerant from a lower pressure (suction pressure) to a higher pressure. The driving force of the ejector is derived from saturated or subcooled liquid after the expansion valve. Accordingly, in accordance with the present invention, there is provided an apparatus for enhancing the performance of a direct expansion refrigeration system, the apparatus comprising a hydrodynamic ejector 7 having an ejector first liquid inlet 71, an ejector second liquid inlet 72 and an ejector liquid outlet 73, an evaporator 9 having a distributor 91 and an outlet header 92, and the distributor having a distributor liquid inlet 13, the outlet header having an outlet header liquid outlet 17 and an outlet header vapor outlet 19, the ejector second liquid inlet 72 being connected to the outlet header liquid outlet 17, the ejector liquid outlet 73 being connected to the distributor liquid inlet 13, the outlet header vapor outlet 19 being configured to be connected to a compressor. According to the embodiment of fig. 5, the ejector first liquid inlet 71 is configured to be connected to the expansion device 3. According to an alternative embodiment shown in fig. 2 to 4, the device may comprise an inlet separator 5. The inlet separator has an inlet separator inlet 51, an inlet separator first outlet 52 and an inlet separator second outlet 53, wherein the inlet separator first outlet 52 is a liquid outlet, the inlet separator first outlet 52 is connected to an ejector first liquid inlet 71, and the inlet separator inlet 51 is configured to be connected to the expansion device 3. According to the embodiment of fig. 2, the inlet separator second outlet 53 is a steam outlet, which is connected to the second (steam) inlet 15 of the distributor 91. According to the embodiment of fig. 3, the inlet separator second outlet 53 is a steam outlet connected to the outlet header 92 or the outlet header steam outlet 19 of the evaporator. According to the embodiment shown in fig. 4, the inlet separator second outlet 53 is a liquid and vapor outlet connected to the second (liquid and vapor) inlet 15 of the distributor. According to a further embodiment of the invention, the inlet separator and the ejector may be combined in an integrated refrigerant recycling device. Other embodiments may include a heat exchanger coupled to the expansion device for providing cooled refrigerant to the expansion device. According to another embodiment of the present invention, a direct expansion refrigeration system is provided that includes refrigerant lines connecting in sequence an expansion device, an inlet separator, a hydrodynamic ejector, an evaporator, and a compressor. The inlet separator is configured to continuously deliver liquid refrigerant to the ejector while simultaneously delivering refrigerant vapor to the evaporator inlet or evaporator outlet. The hydrodynamic ejector is configured to continuously receive liquid refrigerant from the inlet separator and simultaneously receive liquid refrigerant from the evaporator outlet and deliver liquid refrigerant to the evaporator inlet. According to any of the foregoing embodiments, the evaporator outlet header may be replaced by or followed by a phase separator/accumulator to collect and separate refrigerant vapor and liquid from the evaporator, deliver liquid refrigerant to the second liquid inlet of the ejector, and deliver refrigerant vapor to the compressor. It should be noted that while certain features and elements described above and below are described in the context of other selected features, elements, and/or embodiments, it is to be understood that each combination and subcombination of the features and elements described herein is contemplated to be within the scope of the invention. Drawings Fig. 1 is a schematic diagram of a standard direct expansion refrigeration system. Fig. 2 is a schematic view of a first embodiment of the invention wherein steam leaving the inlet separator is delivered to the evaporator/evaporator distributor. Fig. 3 is a schema