Patent Application
20250035349
The present invention relates to refrigeration evaporators and systems in which potentially undesirable interactions between liquid phase and vapour phase refrigerants are alleviated or mitigated.
Any references to methods, apparatus or documents of the prior art are not to be taken as constituting any evidence or admission that they formed, or form part of the common general knowledge.
The cost of mains power has historically been relatively inexpensive. However, it is anticipated that as we move to reduce our reliance on fossils fuels and increase the use of renewable energy, the cost of electricity may continue to increase. The increasing costs of electricity has motivated consumers to reduce their energy costs by installing solar and other ‘off grid’ systems, many of which have a prohibitive initial setup cost, for example, in the provision of solar arrays and expensive battery banks. In residential and commercial settings, refrigeration often results in a significant load requirement. Currently there many different refrigeration system designs in the market aimed at reducing power consumption to meet the energy compliance requirements of some countries.
Portable or mobile refrigeration systems have generally been designed based on scaling down of existing domestic and industrial designs. The existing portable systems generally rely on batteries to provide stored energy for consumption. It is anticipated that in the case of portable or solar based systems, reducing electricity consumption may provide significant benefits.
Start up zone—Each time the compressor in existing systems is powered ON it takes time for the system to stabilise and provide liquid refrigerant into the evaporator. During this time the compressor is consuming power and not providing efficient cooling. The higher the cycle rate, that is, the higher the rate of cycling from ON to OFF per hour/day to maintain storage compartment temperature, the more time the compressor consumes power inefficiently.
Existing systems use a high cycle rate to maintain compartment temperatures, especially in high ambient conditions. This is required due to an inability to hold compartment temperatures stable for any length of time.
An example of the duty cycle of an existing refrigeration system is provided in
Lead acid batteries—When DC compressors startup they use a higher current until the system stabilises. The higher current load will reduce the available energy from a lead acid battery. Lead acid batteries have internal losses that increase with load current.
Thermal heat transfer—Thermal heat transfer relies on thermal transfer from the cooling (evaporator) plate to the air inside the refrigerator storage compartment. Transferring heat energy from air to the evaporator is inherently inefficient and requires a large surface with a low temperature on the plate to create the necessary temperature difference (TD) between the evaporator plate and the air to maintain the storage compartment temperature. Often the TD between the evaporator and storage compartment temperature is 10-15 C. The compressor can only be operated for a short time at that TD otherwise the product nearest the evaporator will start to have a lower storage temperature than is desired. This can result in the product freezing when it is only suitable for fridge temperature storage.
Due to this thermal heat transfer it is difficult to maintain a consistent temperature in all areas of the storage compartment. To overcome this, some systems use a fan which has the benefit of reducing TD between the evaporator and the storage compartment. This may also help to provide a uniform temperature throughout the storage compartment.
Cabinet hold time-Storage compartment temperatures in conventional systems can only hold for a short duration without the system operating. The holding time is generally dependent on the size of the storage compartment, density, thickness and thermal conductivity of the insulation and the TD between the inside compartment temperature and the outside atmospheric temperature.
Portable refrigeration systems are often used in applications where size and weight are important factors. This puts constraints on the thickness and density of the insulation. The market is also very cost sensitive and therefore keeping the price low is also an important factor in product design versus cabinet efficiency.
Due to these factors the running time per day can be as high as 25-100%.
Noise and heat—In many instances portable and mobile refrigeration systems are installed in close proximity to a sleeping area. The compressor will generally generate a significant amount of heat and noise during the ON cycle, with fans cycling during the night. This is detrimental to overnight operation so far as user convenience is concerned.
In conventional evaporator systems, it is considered that reduced efficiencies are often experienced due to the flow of liquid and vapour through the evaporator. Generally, the liquid flows to the lowest point and collects in an accumulator. An example of such a conventional system and its start-up operation is illustrated in
Many systems feed the liquid into the bottom of the evaporator and then use the expanding vapour and suction from the compressor to move slugs of liquid through the combined path to the top of the evaporator. This results in more liquid collecting in the bottom section of the evaporator, hence reducing the effective thermal transfer area and creating colder temperatures in the bottom section of the compartment.
One path—Existing evaporators have one combined liquid and vapour path through the evaporator.
Vapour and liquid thermal transfer—Compared to liquid, heat transfer through vapour is significantly less efficient. As the amount of vapour increases in the evaporator the less heat load that can be absorbed.
Liquid slugs—As the liquid is injected into the evaporator plate a portion of the liquid boils off to vapour. This vapour then expands and displaces the liquid in contact with the metal surface of the evaporator plate. The suction pressure from the compressor draws the vapour towards the compressor and this in turn draws slugs of liquid with it as it moves through the evaporator. The last section of the evaporator plate may be designed to be an accumulator to trap the liquid and prevent it reaching and damaging the compressor.
Accumulator liquid concentration and ice build-up—The liquid accumulates primarily in the accumulator or one section of the evaporator plate resulting in inconsistent ice build-up, mostly around this section. Ice is an insulator and therefore reduces the thermal heat load to the liquid. The end result is a lower suction pressure/temperature required to enable thermal heat transfer through the ice layer. The thicker the ice layer the greater the TD between the liquid and the storage compartment and the lower the system efficiency.
Large evaporators—Large evaporator plates are generally required due to the inefficient thermal transfer from the storage compartment air to the plate. Often the evaporator plate constitutes a complete inner liner to the cabinet and is bonded to the insulation. This reduces production cost but also reduces the system performance (efficiency). This is evident when the inside storage compartment temperature is reduced and/or outside ambient temperature increased. The TD of the evaporator plate to storage compartment air temperature is typically about 10-15° C. This results in the evaporator temperature being −10 to −15° C. The lower the evaporator temperature the lower the COP (coefficient of performance) achieved. Generally the COP of refrigerators is about 1.
Liquid traps—To increase liquid transfer, existing designs trap liquid along the path through the evaporator plate. Often a small bypass section is added to trap the liquid. This has minimal effect due to the liquid flowing to the lowest points, and liquid that is boiling off creating sections of trapped vapour that push the liquid along the tubing out of the liquid trap. In practice, the top section of the trap is often filled with vapour. The rapid expansion of the liquid as it boils off to vapour easily displaces the liquid around it, pushing it out of the liquid traps.
Liquid volume in the system—One solution is to increase the liquid volume in the evaporator by increasing the refrigerant charge. This generally results in improved evaporator performance, but will also cause liquid flood back to the compressor at different ambient temperature conditions. Managing this can require additional accumulators or mechanical and/or electronic controls which increase the manufacturing cost of the system. Additional accumulators and/or increased refrigerant charge may also increase thermal inefficiencies of the system and limit the compressor's ability to draw off the vapour at a sufficient rate to lower and maintain the required evaporator temperature/pressure for constant storage compartment conditions at different ambient temperatures.
Consistent storage compartment temperatures and gradients-Maintaining consistent temperatures throughout the storage compartment/s in a refrigeration system is always a challenge. Portable refrigerators, due to their design, generally have poor performance in maintaining constant temperatures in all areas of the storage compartment. Typically, the static evaporator surface area is large so as to provide thermal heat transfer to a large part of the storage compartment and hence are installed in close proximity to the products being stored. The evaporators operate at a large TD due to their inefficient thermal design, often resulting in product being too cold or frozen when located close to the evaporator plate and not cold enough in the middle and upper areas of the storage compartment. Many models incorporate a basket to hold the product away from direct contact with the evaporator plate. The basket also assists with air flow around the product and provides an easy solution for the consumer to remove the contents for restocking or cleaning. The existing designs usually have a high duty cycle to assist with maintaining stable storage compartment temperatures.
Dual cabinet refrigerators-Some products provide a dual compartment cabinet which allows the customer to store products at fridge (fresh food) temperatures in one section and freezer temperatures in a different section. The use of one evaporator to achieve this often results in poor performance of the system, particularly with regard to the fridge cabinet temperature and extra power usage. Typically, the most common and simplest method of temperature control involves using the evaporator plate temperature to control the duty cycle. In a dual cabinet system, the evaporator is located in the freezer compartment.
In an aspect, the invention provides a refrigeration evaporator for use in refrigeration systems, the evaporator comprising:
In an embodiment, each respective vapour channel is located along an in-use upper portion of the corresponding liquid chamber.
In an embodiment, the overflow inlets for each liquid chamber is fluidly connected with respective overflow channels disposed along peripheral regions of corresponding liquid chambers and wherein the vapour channels are disposed radially outwardly relative to the overflow channels.
In an embodiment, each liquid chamber comprises a bottom wall, a top wall and side walls such that inner surfaces of the bottom wall, top wall and side walls define a substantially enclosed internal volume for accumulating the liquid refrigerant such and wherein outer surfaces of one or more of the top wall, side wall and bottom wall define at least a portion of the overflow channels.
In an embodiment, the overflow outlet for each liquid chamber is located to direct the overflow of the liquid refrigerant along the outer surface of the top wall of said each liquid chamber defining a portion of the overflow channel to spread the overflowing liquid along the outer surface of the top wall and facilitate vapour draw off from the overflow channel into the peripherally disposed vapour channels.
In an embodiment, each liquid chamber is surrounded by an outer peripheral walls such that an inner surface of the outer peripheral walls define a portion of the overflow channel and an outer surface of the peripheral walls defines a portion of the vapour channels.
In an embodiment, in an in-use configuration, each of the liquid chambers are positioned at different relative heights to allow flow of liquid refrigerant between the plurality of fluidly connected liquid chambers under gravity.
In an embodiment, the refrigeration evaporator further comprises a vapour outlet being fluidly coupled with the vapour circuit to allow coupling of a compressor with the vapour circuit for allowing the compressor, when fluidly connected to the vapour outlet, to receive and compress vapour under high pressure during use.
In an embodiment, the vapour circuit and the overflow inlets and outlets are disposed between the first and second layers of roll bonded metal.
In another aspect, the invention provides a refrigeration system comprising:
In another aspect, the invention provides a refrigeration evaporator for use in refrigeration systems, the evaporator comprising:
In an embodiment, each respective vapour channel is located along an in-use upper portion of the corresponding liquid chamber.
In an embodiment, the overflow inlets for each liquid chamber is fluidly connected with respective overflow channels disposed along peripheral regions of corresponding liquid chambers and wherein the vapour channels are disposed radially outwardly relative to the overflow channels.
In an embodiment, each liquid chamber comprises a bottom wall, a top wall and side walls such that inner surfaces of the bottom wall, top wall and side walls define a substantially enclosed internal volume for accumulating the liquid refrigerant such and wherein outer surfaces of one or more of the top wall, side wall and bottom wall define at least a portion of the overflow channels.
In an embodiment, the overflow outlet for each liquid chamber is located to direct the overflow of the liquid refrigerant along the a stepped portion of each liquid chamber, the stepped portion defining a portion of the overflow channel to spread the overflowing liquid along the outer surface of the stepped portion and facilitate vapour draw off from the overflow channel into the peripherally disposed vapour channels.
In an embodiment, each liquid chamber is surround by outer peripheral walls such that an inner surface of the outer peripheral walls define a portion of the overflow channel and an outer surface of the peripheral walls defines a portion of the vapour channels.
In an embodiment, in an in-use configuration, each of the liquid chambers are positioned at different relative heights to allow flow of liquid refrigerant between the plurality of fluidly connected liquid chambers under gravity.
In an embodiment, the refrigeration evaporator further comprises a vapour outlet being fluidly coupled with the vapour circuit to allow coupling of a compressor with the vapour circuit for allowing the compressor, when fluidly connected to the vapour outlet, to receive and compress vapour under high pressure during use.
In an embodiment, the refrigeration evaporator further comprises a plurality of fins associated with plurality of conduits forming the vapour circuit.
In another aspect, the invention provides a refrigeration system comprising:
In yet another aspect, there is provided a refrigeration evaporator for use in refrigeration systems, the evaporator comprising:
In an embodiment, vapour flow paths are located along in-use upper portions of an internal volume of the liquid chambers.
In an embodiment, the overflow inlets for each liquid chamber is fluidly connected with respective overflow channels disposed along peripheral regions of corresponding liquid chambers and wherein the vapour flow paths are disposed within the overflow channels.
In an embodiment, each liquid chamber comprises a bottom wall, a top wall and side walls such that inner surfaces of the bottom wall, top wall and side walls define a substantially enclosed internal volume for accumulating the liquid refrigerant and wherein the overflow outlet for one or more liquid chambers comprises a stepped portion along a side wall that is sufficiently spaced away from the top wall to allow to facilitate flow of vapour along the vapour flow paths in an upper portion of the liquid chamber, the upper portion being at or adjacent the top wall of the liquid chamber for reducing interaction between the vapour and the liquid refrigerant during use.
In an embodiment, the stepped portion defines a portion of the overflow channel to spread the overflowing liquid along the outer surface of the stepped portion and facilitate vapour draw off from the overflow channel into the peripherally disposed vapour channels.
In an embodiment, each liquid chamber is surrounded by outer peripheral walls such that an inner surface of the outer peripheral walls defines a portion of the overflow channels.
In an embodiment, in an in-use configuration, each of the liquid chambers are positioned at different relative heights to allow flow of liquid refrigerant between the plurality of fluidly connected liquid chambers under gravity.
In an embodiment, the refrigeration evaporator further comprises a vapour outlet being fluidly coupled with the vapour circuit to allow coupling of a compressor with the vapour circuit for allowing the compressor, when fluidly connected to the vapour outlet, to receive and compress vapour under high pressure during use.
In an embodiment, influent flow rate of the liquid refrigerant through the fluidly connected chambers is controlled by a controller.
In another aspect, the invention provides a refrigeration evaporator for use in refrigeration systems, the evaporator comprising:
Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows:
Hereinafter, this specification will describe the present invention according to the preferred embodiments. It is to be understood that limiting the description to the preferred embodiments of the invention is merely to facilitate discussion of the present invention and it is envisioned without departing from the scope of the appended claims.
Referring to
With reference to
In stage B as more liquid 202 flows into the evaporator plate 200, the liquid 202 starts to accumulate as there is more than can be boiled off through thermal conduction from the air. This liquid 202 then progressively makes it further through the evaporator plate 200.
In stage C the liquid 202 starts to fill the accumulator 206, and suction pressure continues to drop maintaining the thermal load from the air. However, as the suction pressure drops so does the COP. As the cabinet temperature gets close to the evaporating temperatures the suction pressure continues to drop as the thermal load “rolls off”. As the load continues to drop off the liquid 202 builds up in the accumulator 206 and eventually overflows to a liquid overflow. This liquid overflow 208 triggers a thermostat sensor to shut off the compressor to prevent flood back.
As the liquid 202 pools in the accumulator 206 at the bottom of the evaporator plate 200 it reduces the effective thermal transfer area of the evaporator plate 200. The liquid 202 continues to build up in the accumulator 206 until it forms a liquid seal over the suction line 208 through which vapour exits the evaporator plate 200. The vapour in the top of the evaporator plate 200 pushes on the accumulated liquid while the suction from the compressor pulls on the liquid that has sealed the suction line 208. This can cause flood back of liquid into the compressor. There is no way for the vapour to be drawn out of the evaporator plate 200 once the accumulator 206 is flooded with liquid Adding more gas to the system will increase performance as it maintains a higher evaporator temperature. However, this also increases the build-up of liquid 202 in the accumulator 206. Due to the potential for flood back to damage the compressor the thermostat shuts off the system before the cabinet has reached the required temperature.
Referring to
Unlike previous designs in which liquid passes through a meandering channel including a number of spaced liquid traps to ultimately end up in an accumulator, as illustrated in
The first liquid chamber 310a receives liquid 312 entering the evaporator 300 via the liquid inlet 306 which is disposed above a first liquid chamber inlet 314a. The liquid inlet 306 includes a capillary 307 that extends into the first liquid chamber 310a. When the first liquid chamber 310a is full, liquid 312 flows out of the first liquid chamber inlet 314a into a first liquid overflow 316a. The overflowing liquid travels along the first liquid overflow 316a into a first overflow channel 318a disposed around the peripheral walls of the first liquid chamber 310a.
The overflowing liquid then enters the second liquid chamber 310b via a second liquid chamber inlet 314b. When the second liquid chamber 310b is full, liquid 312 flows out of the second liquid chamber inlet 314b into a second liquid overflow 316b. The overflowing liquid travels along the second liquid overflow 316b into a second overflow channel 318b disposed around the peripheral walls of the second liquid chamber 310b.
The overflowing liquid then enters the third liquid chamber 310c via a third liquid chamber inlet 314c. Therefore, each of the liquid chambers 314a, 314b and 314c are interconnected by respective overflow inlets and outlets to allow flow of liquid refrigerant between the plurality of fluidly connected liquid chambers under gravity such that during influent flow of the refrigerant liquid through the inlet, the liquid chambers 314a, 314b and 314c accumulate the refrigerant liquid sequentially to impede the flow of the refrigerant liquid.
In conventional evaporators, as for example illustrated in
More specifically, the vapour circuit 320 includes a first vapour draw off channel 322a in communication with the first liquid overflow 316a of the first liquid chamber 310a. Vapour formed in the first liquid overflow 316a and the first overflow channel 318a disposed around the peripheral walls of the first liquid chamber 310a flows into the first vapour draw off channel 322a and into a peripheral vapour channel 324 in fluid communication with the vapour outlet 308.
A second vapour draw off channel 322b is in communication with the second liquid overflow 316b of the second liquid chamber 310b. Vapour formed in the second liquid overflow 316b and the second overflow channel 318b disposed around the peripheral walls of the second liquid chamber 310b flows into the second vapour draw off channel 322b and into the peripheral vapour channel 324.
A third vapour draw off channel 322c is in communication with the third liquid chamber 310c. Vapour in the third liquid chamber 310c flows into the third vapour draw off channel 322c and into the peripheral vapour channel 324. Therefore, the vapour circuit 320 comprises respective draw off vapour channels 322 to receive flow of refrigerant vapour from corresponding liquid chambers whereby the draw off vapour channels 322 are in fluid communication with peripheral vapour channels 324 disposed along peripheral regions of the evaporator 300 for reducing or preventing slugs of liquid refrigerant flowing into the vapour circuit 320. Each respective draw off vapour channel 322 is located along an in-use upper portion of the corresponding liquid chamber 310.
The overflow inlets 316a for each liquid chamber 310 is fluidly connected with respective overflow channels disposed along peripheral regions of corresponding liquid chambers 310. Each vapour draw off channel 322B is fluidly connected with vapour channels that are disposed radially outwardly relative to the peripheral overflow channels.
According to this design, the flow of the liquid within the evaporator 300 is not significantly impacted by the flow of vapour within the evaporator 300. Moreover, the distribution of the liquid within the evaporator is much more even as compared with conventional evaporator plates, given the inclusion of more than one accumulation area within the evaporator 300. In that regard, although three liquid chambers 310a, 310b and 310c are illustrated, it is considered that two liquid chambers may be appropriate in certain circumstances. Likewise, four, five, six or more liquid chambers may also be appropriate. To that end, the invention is not restricted to only three liquid chambers as illustrated.
The second liquid chamber 310b and third liquid chamber 310c include connecting portions 326 disposed within the second liquid chamber 310b and third liquid chamber 310c and extending between and connecting the first layer and the second layer of the evaporator 300. The connecting portions 326 advantageously provide improved strength to the second liquid chamber 310b and third liquid chamber 310c. While not illustrated the first liquid chamber 310a may also include such connecting portions 326.
As illustrated in
When the evaporator 300 is tipped to such an angle, liquid within the first liquid chamber 310a overflows more significantly into the first liquid overflow 318a, but does not transfer into the first vapour draw off channel 322a. Likewise, liquid within the second liquid chamber 310b overflows more significantly into the second liquid overflow 318b, but does not transfer into the second vapour draw off channel 322b. Liquid within the third liquid chamber 310c is disposed more to the side to which the evaporator 300 is leaning, but not to the extent that it overflows into the third vapour draw off channel 322c.
As can be clearly seen particularly in
As shown clearly in
In addition to the liquid flow within the evaporator 300, vapour within the three liquid chambers 310a, 310b and 310c can escape into the first vapour draw off channel 322a, second vapour draw off channel 322b and third vapour draw off channel 322c respectively. Vapour within the evaporator 300 does not get blocked from exiting the vapour outlet 308 by liquid within the evaporator 300. Also, liquid within the evaporator 300 is still relatively well dispersed across the evaporator 300.
It would be understood that the refrigeration evaporator 300 may be used in combination with a compressor that is fluidly coupled to the vapour circuit 320 of the evaporator 300 for receiving and compressing vapour under high pressure; and a condenser in fluid communication with the compressor for receiving the compressed vapour from the compressor and condensing the compressed vapour to form liquid refrigerant and fluidly coupling the condenser to pass the liquid refrigerant to the liquid inlet 306.
Referring to
As illustrated, the liquid inlets 502 are disposed on an upper left corner of the liquid chambers 510a, 510b, 510c and 510d and the vapour outlets 504 are disposed on an upper left corner of the liquid chambers 510a, 510b, 510c and 510d. As liquid enters the liquid chambers 510a, 510b, 510c and 510d it flows into a lower portion of the liquid chamber 510a, 510b, 510c and 510d where it boils off. The vapour produced exits at the vapour outlets 504 at the upper opposing side of the liquid chambers 510a, 510b, 510c and 510d.
As the liquid is in the lower portion of the liquid chambers 510a, 510b, 510c and 510d, interaction with vapour is minimised. Moreover, the vapour within the thermal transfer device 500 does not force the liquid through the thermal transfer device 500, and the liquid does not impinge on the vapour outlets 504.
The location of the liquid chambers 510a, 510b, 510c and 510d on the thermal transfer device 500 has the added advantage of more evenly distributing the liquid across the thermal transfer device 500, as opposed to being collected in an accumulator of the device. It is noted that the illustrated vapour exits may be prone to flood back due to the rapidly expanding vapour throwing the liquid up and into the vapour outlet. The compressor suction may then disadvantageously draw the liquid out the vapour path and cause flood back. The design and area around the vapour outlet may be provided with a different design to that shown to address such issues.
Referring to
The stepped portions 607 are in communication with the overflow conduits 604 such that when the liquid conduits 602 are full, liquid overflows the stepped portions 607 into the overflow conduits 604 and into a subsequent liquid conduit 602.
A plurality of vapour conduits 608 are in communication with the plurality of fluidly connected liquid conduits 602 and adapted to receive vapour exiting the liquid conduits 602. A number of the vapour conduits 608 that form draw off vapour channels are disposed on an upper side and spaced along the length of each of the liquid conduits 602, thereby facilitating draw off of vapour along the length of each liquid conduit 602. These vapour draw off channels direct the vapour to peripheral vapour channels denoted by 612 that are located along peripheral regions of the evaporator 600. The liquid conduits 602 are of a diameter that will facilitate separation of the vapour to an upper region of the liquid conduits 602 where it can be drawn off into the vapour conduits 608. The vapour conduits 608 are in communication with a respective vapour circuit conduit 610 constituting part of a vapour circuit 612. The vapour circuit 612 is in communication with a vapour outlet 614 for removing vapour from the vapour circuit 612.
The thermal transfer device 600 further comprises a plurality of fins 616 associated with the plurality of liquid conduits 602. The fins 616 advantageously increase the surface area available for thermal transfer.
It would be understood that the refrigeration evaporator 600 may be used in combination with a compressor that is fluidly coupled to the vapour circuit 612 of the evaporator 600 for receiving and compressing vapour under high pressure; and a condenser in fluid communication with the compressor for receiving the compressed vapour from the compressor and condensing the compressed vapour to form liquid refrigerant and fluidly coupling the condenser to pass the liquid refrigerant to the liquid inlet 606.
Turning to
The thermal transfer device 700 includes a plurality of interconnected liquid collectors 704 and a plurality of liquid inlets 706 for introducing liquid to the liquid collectors 704 and a plurality of vapour outlets 708 for removing vapour from the thermal transfer device 700. Once again, each of the liquid collectors 704 are interconnected by overflow channels or portions 710 to allow flow of liquid refrigerant between the plurality of fluidly connected liquid chambers under gravity such during influent flow of the refrigerant liquid the liquid chambers accumulate the refrigerant liquid sequentially to impede the flow of the refrigerant liquid.
Each of the liquid collectors 704 are fluidly connected to one another by the overflow portion 710. The overflow portions 710 are disposed on consecutive liquid collectors 704. As will be appreciated from the illustration, the overflow portions 710 are also of a diameter that will facilitate flow of vapour without significant interaction with liquid within the thermal transfer device 700. As a result, the vapour circuit comprising vapour flow paths is disposed within the overflow portions 710. The overflow inlets for each liquid collector 704 is fluidly connected with the respective overflow channels 710 disposed along peripheral regions of corresponding liquid collectors 704.
Each liquid collector 704 comprises a bottom wall, a top wall and side walls such that inner surfaces of the bottom wall, top wall and side walls define a substantially enclosed internal volume for accumulating the liquid refrigerant. The overflow outlet 710 for each collector 704 comprises a stepped portion along a side wall that is sufficiently spaced away from the top wall to facilitate flow of vapour along the vapour flow paths in an upper portion of the liquid chamber, the upper portion being at or adjacent the top wall of the liquid chamber for reducing significant interaction between the vapour and the liquid refrigerant during use.
Importantly, each overflow channel 710 comprises a sufficiently large cross-section to facilitate flow of vapour along the vapour flow paths therein to allow the liquid to collect and flow without the vapour pushing slugs of the liquid through the cross-section without blocking the flow of the vapour.
Referring to
Vapour in the compressor 802 is compressed and is discharged from the compressor 802 as hot high pressure vapour and pushed to a condenser 810. The hot high pressure vapour is then cooled and condenses to liquid. The liquid is then fed through a metering device or capillary 808. As the liquid passes through the metering device or capillary 808 the pressure drops and it enters the evaporator 300. The low pressure liquid then boils off to vapour as it absorbs the thermal energy from the cabinet. The vapour is then drawn back to the compressor 802.
In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. The term “comprises” and its variations, such as “comprising” and “comprised of” is used throughout in an inclusive sense and not to the exclusion of any additional features.
It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect.
The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted by those skilled in the art.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2019902148 | Jun 2019 | AU | national |
This application is a Continuation of U.S. application Ser. No. 17/555,179, filed on Dec. 17, 2021 which is a Continuation-in-Part of PCT Application No. PCT/AU2020/050590 filed on Jun. 11, 2020, which claims priority benefits of Australian Application No. 2019902148 filed Jun. 20, 2019. The technical disclosures of the applications are hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17555179 | Dec 2021 | US |
| Child | 18916223 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/AU2020/050590 | Jun 2020 | WO |
| Child | 17555179 | US |
