DESC:FIELD
The present disclosure generally relates to chiller applications.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
A conventional chiller application comprises an evaporator, a compressor, an oil separator assembly, a condenser and an expansion valve. When it comes to a large-capacity chiller application, they include two or more than two compressors. Each compressor is connected to the oil separator assembly which contains a demister per compressor discharge for separating oil droplets from the mixture of lubricating oil and refrigerant gas passing there through before going to the condenser. The oil separator assembly needs to be sized based on the demister diameter, which depends upon the maximum allowable velocity for separation in the demister. Since only one demister per compressor is used in the oil separator, all the discharge flow rate of the operative compressor passes through the demister. This leads to a larger diameter of the demister & thereby oil separator assembly. The chiller usually runs at part load conditions, with only one compressor operating, and therefore its full capacity is mostly not utilized. Therefore, only the demister of the operative compressor is used to separate the oil from the oil-and-gas mixture during part load conditions. This may lead to a similar pressure drop as that during full load conditions, but at a lower oil separation efficiency as other demisters are not utilized.
To recover the unseparated oil from the evaporator of flooded chillers an oil recovery line(s) is provided which however leads to waste of discharge gas energy, thereby reducing the efficiency of the chiller. At times if the oil recovery line is kept inoperative, the oil droplets start accumulating in the evaporator, thereby quickly deteriorating the capacity of the evaporator and therefore the coefficient of performance. An oil separator of a larger diameter increases the shell size and weight of the conventional chiller application therefore saddle supports are required to sustain the weight of the chiller application, specifically the oil separator assembly. Further, discharge pipe bends are also necessary to connect the compressor discharge port with the oil separator inlet. Additionally, connecting the oil separator outlet to the condenser inlet requires discharge pipe bends and a longer discharge pipe. Adding these elements further increases the weight of the chiller application. Further, these elements act as obstructions causing pressure drop in the gas flow. These flow obstructions, tend to lower the efficiency of the chiller as the compressor has to overcome this additional pressure drop. Further, accommodating the oil separator assembly of larger diameter in a chiller of constrained dimensions is difficult & costly.
There is therefore felt the need for an improved oil separator assembly which alleviates the aforementioned drawbacks.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
An object of the present disclosure is to provide an oil separator assembly for a chiller application.
Another object of the present disclosure is to provide an oil separator assembly for a chiller application which facilitates a relatively efficient oil separation at part load operation & relatively lower pressure drop.
Yet another object of the present disclosure is to provide an oil separator assembly for a chiller application which prevents rapid deterioration of the chiller application.
Still another object of the present disclosure is to provide an oil separator assembly which improves the efficiency of a chiller application.
Another object of the present disclosure is to provide an oil separator assembly for a chiller application which has a relatively better cooling efficiency at a lower cost.
Another object of the present disclosure is to provide an oil separator assembly for a chiller application, which can directly be mounted over the condenser shell using the refrigerant outlet pipes thereby eliminating the need for dedicated saddle supports.
Yet another object of the present disclosure is to provide an oil separator assembly which lowers the overall weight of the chiller application.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages an oil separator assembly for a chiller application, which is configured to be employed in a compressor set having a plurality of compressor units.
The oil separator assembly comprises a cylindrical housing having a first end and a second end. At least one inlet pipe is configured to extend into the housing from an operative top portion of the housing to introduce a lubricating oil-and-gas mixture into the housing. At least one oil outlet pipe is configured to extend from within the housing to an operative top portion of the housing. At least two refrigerant outlet pipes are configured to extend from within the housing to an operative bottom portion of the housing. A plurality of baffles is configured to be arranged within the housing at a spaced apart distance from each other to define a plurality of compartments therebetween. The assembly further comprises at least one demister provided on each side of the compartments. The demister is configured to receive the lubricating oil-and-gas mixture and facilitate the separation of oil droplets from the mixture. Each of the demisters is configured to be in its operative configuration irrespective of the operative status of individual compressors, thereby reducing the oil carry-over rate at part load of the chiller application. Further, the separated oil is returned to the compressor through the oil outlet pipe and the demisted refrigerant gas is discharged out through the refrigerant outlet pipes into the condenser assembly.
In an embodiment, each demister is configured to separate droplets of oil from the lubricating oil-and-gas mixture passing through the oil separator assembly.
In an embodiment, the baffles are configured to direct the flow of the lubricating oil-and-gas mixture through each compartment in a sequential and parallel manner, thereby reducing the oil load on each demister for enhanced oil separation efficiency.
In an embodiment, each baffle is positioned at an angle relative to the flow direction of the lubricating oil-and-gas mixture to create a tortuous flow path through the compartments, thereby enhancing the separation efficiency by increasing the residence time of the oil-and-gas mixture within the housing.
In an embodiment, each demister has a relatively lesser surface area and diameter, wherein the diameter of each demister is approximately 25% smaller than a conventional demister.
In an embodiment, the weight of the oil separator assembly is relatively reduced by 10% to 40%.
In an embodiment, the refrigerant charge requirement is relatively reduced by 25% to 45%.
In an embodiment, the oil separation efficiency of the oil separator assembly is relatively increased by 5% during part load conditions due to the operative configuration of all demisters at reduced flow rates.
In another embodiment, which is configured to be directly mounted over a condenser shell of the chiller application, using the refrigerant outlet pipes, thereby eliminating the need for dedicated saddle supports.
In yet another embodiment, the oil outlet pipes are configured to fluidly communicate with an oil reservoir provided at the bottom of the oil separator assembly in fluid connection with the compressor oil inlet ports.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
An oil separator assembly, of the present disclosure, for a chiller application will now be described with the help of the accompanying drawing in which:
Figure 1 illustrates an isometric view of a conventional chiller application;
Figure 2 illustrates a front view of the conventional chiller application of Figure 1;
Figure 3 illustrates a schematic view of the conventional chiller application of Figure 1;
Figure 4A illustrates an isometric view of oil separator of the conventional chiller application of Figure 1;
Figure 4B illustrates a schematic view of oil separator of Figure 3A;
Figure 5 illustrates an isometric view of conventional chiller application having two compressors;
Figure 6 illustrates a schematic view of the conventional chiller application of Figure 5;
Figure 7A illustrates an isometric view of the oil separator of the conventional chiller application of Figure 5;
Figure 7B illustrates a schematic view of the oil separator of Figure 8A;
Figure 8 through Figure 11 illustrate schematic views of the oil separator assembly provided with a plurality of demisters of the present disclosure;
Figure 12 illustrates a schematic view of the chiller application of Figure 9; and
Figure 13 illustrates a schematic view of the chiller application of Figure 10.
LIST OF REFERENCE NUMERALS
10 – conventional chiller application
15 – evaporator
20 – compressor
25 – condenser
30 – expansion valve
32 – demister
35 – oil separator assembly
45 – saddle support
50 – inlet pipe bend
55 – discharge bend
60 – pipe
120 – oil separator assembly of the present disclosure
122 – cylindrical housing
122A – first end of the housing
122B – second end of the housing
123A, 123B,…..123n – compartments
124 – baffles
125A, 125B,…..125n – demisters
126A, 126B,……126n – inlet pipe
128A, 128B – oil outlet pipe
130A, 130B,….130n – refrigerant outlet pipe
200 – chiller application with oil separator assembly of the present disclosure
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are open-ended transitional phrases and therefore specify the presence of stated features, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, elements, components, and/or groups thereof.
A conventional chiller application (10), as shown in Figure 1 through Figure 8B, comprises an evaporator (15), a compressor (20), an oil separator assembly (35), a condenser (25) and an expansion valve (30). When it comes to a large-capacity chiller application (10), such chillers comprise two or more than two compressors. Each compressor (20) is connected to the oil separator assembly (35). The oil separator assembly (35) contains a demister per compressor discharge for separating oil droplets from the mixture of lubricating oil and refrigerant gas passing there through before going to the condenser (25). The oil separator assembly (35) needs to be sized based on the demister (32) diameter which in turn depends upon the maximum allowable velocity for separation in the demister (32). Since only one demister (32) per compressor (20) is used in the oil separator, all the discharge flow rate of the operative compressor passes through the demister (32). This leads to a larger diameter of the demister and thereby oil separator assembly (35). The chiller usually runs at part load conditions, with only one compressor operating, and therefore its full capacity is mostly not utilized. Therefore, only the demister (32) of the operative compressor is used to separate the oil from the oil-and-gas mixture during part load conditions. This may lead to similar pressure drop as that during full load conditions but at lower oil separation efficiency as another demister is not utilized.
To recover the unseparated oil from the evaporator (15) of flooded chillers an oil recovery line(s) (not shown) is provided which however leads to waste of discharge gas energy, thereby reducing the efficiency of the chiller. At times if the oil recovery line is kept inoperative, the oil droplets start accumulating in the evaporator (15), thereby quickly deteriorating the capacity of the evaporator and therefore the coefficient of performance. An oil separator of a larger diameter increases the shell size and weight of the conventional chiller application therefore, saddle supports are required to sustain the weight of the chiller application, specifically the oil separator assembly. Further, discharge pipe bends are also necessary to connect the compressor discharge port with the oil separator inlet. Additionally, connecting the oil separator outlet to the condenser inlet requires discharge pipe bends and a longer discharge pipe. Adding these elements further increase the weight of the chiller application. Further, these elements act as obstructions causing pressure drop in the gas flow. These flow obstructions, tend to lower the efficiency of the chiller as the compressor has to overcome this additional pressure drop. Further, accommodating the oil separator assembly of larger diameter in a chiller of constrained dimensions is difficult & costly.
There is therefore felt the need for an improved oil separator assembly (120).
A preferred embodiment of an oil separator assembly (120) of the present disclosure (hereinafter referred to as ‘the assembly’), for a chiller application (200) will now be described in detail with reference to Figure 8 through Figure 13. The preferred embodiment does not limit the scope and ambit of the present disclosure.
The oil separator assembly (120) is configured to be used in the chiller application. The chiller application (200) is employed in a compressor set (20) having a plurality of compressor units.
In an embodiment, the chiller application may include at least one compressor (20) provided there within. In another embodiment, the chiller application may include two compressors (20) provided there within. In another embodiment, the chiller application (200) may include three compressors (20) provided there within.
The assembly comprises a cylindrical housing (122) with a first end (122A) and a second end (122B) as shown in Figure 8.
Further, the assembly (120) includes at least one inlet pipe (126A, 126B,... 126n) configured to extend into the housing (122) from its operative top portion. The inlet pipe (126A, 126B,... 126n) is configured to introduce the oil-and-gas mixture into the housing (122).
In an embodiment, the assembly includes plurality inlet pipe (126A, 126B,... 126n) as shown in Figure 9 to Figure 11.
At least one oil outlet pipe (128A, 128B) is configured to extend from within the housing (122) to the operative top portion. The oil outlet pipe (128A, 128B) is configured to return the oil to the compressor. At least two refrigerant outlet pipes (130A, 130B,... 130n) are configured to extend from within the housing (122) to its operative bottom portion. The refrigerant outlet pipes (130A, 130B,... 130n) are configured to discharge the demisted gas into the condenser. In an embodiment, the assembly (120) is configured to be directly mounted over a condenser shell of the chiller application, using the refrigerant outlet pipes (130A, 130B,….130n). The refrigerant outlet pipes (130A, 130B,... 130n) support the weight of the oil separator assembly (120), thereby eliminating the need for dedicated saddle supports (45) on the oil separator assembly and also on the condenser (25) assembly.
A plurality of baffles (124) is configured to be arranged within the housing (122) at a spaced apart distance from each other to form a plurality of compartments (123A, 123B,... 123n). The baffles (124) are configured to direct the flow of the oil-and-gas mixture and optimize the separation efficiency. Each demister (125A, 125B,…..125n) provided in each side of the compartments (123A, 123B,…..123n), is configured to capture and separate oil droplets from the oil and gas mixture flowing through the compartment (123A, 123B,... 123n). The demisters (125A, 125B,... 125n) are configured in their operative configuration even if one of the compressors (20) is in an inoperative configuration, thereby reducing the oil carry-over rate at part load of the chiller application (200). As a result, at part load oil carry-over rate is relatively lower on one side as all the demisters (125A, 125B,... 125n) are used at the same time. The demisted gas is passed through the refrigerant outlet pipes (130A, 130B,….130n) into the condenser (25), while the separated oil is returned to the compressor (20) through the oil outlet pipes (128).
In an embodiment, each demister (125A, 125B,…..125n) is configured to separate droplets of oil from the oil-and-gas mixture passing through the oil separator assembly (120).
In an embodiment, the baffles (124) are configured to direct the flow of the lubricating oil-and-gas mixture through each compartment (123A, 123B,…..123n) in a sequential and parallel manner, thereby reducing the oil load on each demister (125A, 125B,…..125n) for enhanced oil separation efficiency.
In an embodiment, each baffle (124) is positioned at an angle relative to the flow direction of the lubricating oil-and-gas mixture to create a tortuous flow path through the compartments (123A, 123B,…..123n), thereby enhancing the separation efficiency by increasing the residence time of the oil-and-gas mixture within the housing (122).
In an embodiment, the oil outlet pipes (128A, 128B) are configured to fluidly communicate with an oil reservoir at the bottom of the oil separator assembly (120) to the compressor oil inlet port(s).
In an embodiment, the number of the demister (125A, 125B,…..125n) in the oil separator assembly (120) ranges between 2 to 4. Multiple demisters (125A, 125B,…..125n), all in their operative configuration, help in the efficient separation of oil droplets from the oil-and-gas mixture.
In an embodiment, the oil separator assembly (120) helps in achieving an increase in the efficiency of oil separation by 5% at part load.
In an embodiment, since the flow rate of the lubricating oil-and-gas mixture being passed through the demisters (125A, 125B,…..125n) decreases due to splitting of the flow compared to the oil separator assembly (35) in conventional chiller (10), the required surface area of the demister (125A, 125B,…..125n) decreases. As a result, the size of the demister (125A, 125B,…..125n) decreases. In another embodiment, demister has a relatively lesser surface area and diameter. The diameter of each demister (125A, 125B,…..125n) is approximately 25% smaller than a conventional demister.
Further, the size reduction of the demisters (125A, 125B,…..125n) results in reduced size of the oil separator assembly. The weight of the improved oil separator assembly (120) is approximately 10 to 40 % lower than the conventional oil separator assembly (35) and the corresponding cost reduction by 10 to 30%. The overall weight reduction observed for the chiller application (200) is around 2 %. Additionally, around 25 to 45% of the refrigerant charge is saved in improved oil separator assembly (120) compared to that of the conventional oil separator assembly (35).
Moreover, due to the relatively lesser weight of the oil separator assembly (120), the need for saddle supports (45) as required by conventional separators is also eliminated. Likewise, the inlet pipe bends (50), the discharge bend (55) and the long pipe (60) that were used in conventional compressor assemblies (35) are now eliminated by the use of the oil separator assembly (120) of the present disclosure. As a result, the discharge line pressure drop is significantly lowered as compared to conventional assemblies, while the oil carry-over rate is reduced & the performance has been comparatively improved.
In an embodiment, around a 2% increase in the efficiency of the system has been observed through multiple experiments conducted.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCEMENTS
The present disclosure described hereinabove has several technical advantages including, but not limited to an oil separator assembly for a chiller application, that;
• prevents rapid deterioration of the chiller application;
• improves the efficiency of a chiller application;
• improves the efficiency of oil separation by 5% at part load conditions;
• improves the cooling efficiency of the chiller application by 2%;
• lowers the working cost of the chiller application by 10-20%;
• lowers the overall weight of the chiller application by 2%; and
• minimizes in the chiller application.
The foregoing disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Any discussion of devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
,CLAIMS:WE CLAIM:
1. An oil separator assembly (120) for a chiller application (200), wherein the chiller application (200) is employed in a compressor set (20) having a plurality of compressor units, said oil separator assembly (120) comprising:
• a cylindrical housing (122) having a first end (122A) and a second end (122B);
• at least one inlet pipe (126A, 126B,……126n) configured to extend into said housing (122) from an operative top portion of said housing (122) to introduce a lubricating oil-and-gas mixture into said housing (122);
• at least one oil outlet pipe (128A, 128B) configured to extend from within said housing (122) to an operative top portion of said housing (122);
• at least two refrigerant outlet pipes (130A, 130B,….130n) configured to extend from within said housing (122) to an operative bottom portion of said housing (122);
• a plurality of baffles (124) configured to be arranged within said housing (122) at a spaced apart distance from each other to define a plurality of compartments (123A, 123B,…..123n) therebetween;
• at least one demister (125A, 125B,…..125n) provided in each side of said compartments (123A, 123B,…..123n), said demister (125A, 125B,…..125n) configured to receive the lubricating oil and gas mixture and facilitate separation of oil droplets from the mixture,
wherein, each of said demisters (125A, 125B,…..125n) is configured to be in its operative configuration irrespective of the operative status of individual compressors (20), thereby reducing the oil carry-over rate at a part load of the chiller application (200); and
wherein the separated oil is returned to the compressor through said oil outlet pipe (128A, 128B) and the demisted refrigerant gas is discharged out through said refrigerant outlet pipes (130A, 130B,….130n) into the condenser assembly (25).
2. The oil separator assembly (120) as claimed in claim 1, wherein each demister (125A, 125B,…..125n) is configured to separate droplets of oil from the lubricating oil-and-gas mixture passing through the oil separator assembly (120).
3. The oil separator assembly (120) as claimed in claim 1, wherein said baffles (124) are configured to direct the flow of the lubricating oil-and-gas mixture through each compartment (123A, 123B,…..123n) in a sequential and parallel manner, thereby reducing the oil load on each demister (125A, 125B,…..125n) for enhanced oil separation efficiency.
4. The oil separator assembly (120) as claimed in claim 3, wherein each baffle (124) is positioned at an angle relative to the flow direction of the lubricating oil-and-gas mixture to create a tortuous flow path through the compartments (123A, 123B,…..123n), thereby enhancing the separation efficiency by increasing the residence time of the oil-and-gas mixture within said housing (122).
5. The oil separator assembly (120) as claimed in claim 1, wherein each demister has a relatively lesser surface area and diameter, wherein the diameter of each demister (125A, 125B,…..125n) is approximately 25% smaller than a conventional demister.
6. The oil separator assembly (120) as claimed in claim 1, wherein the weight of said oil separator assembly (120) is relatively reduced by 10% to 40%.
7. The oil separator assembly (120) as claimed in claim 1, wherein the refrigerant charge requirement is relatively reduced by 25% to 45%.
8. The oil separator assembly (120) as claimed in claim 1, wherein the oil separation efficiency of said oil separator assembly (120) is relatively increased by 5% during part load conditions due to the operative configuration of all demisters (125) at reduced flow rates.
9. The oil separator assembly (120) as claimed in claim 1, which is configured to be directly mounted over a condenser shell of the chiller application, using said refrigerant outlet pipes (130A, 130B,….130n), thereby eliminating the need for dedicated saddle supports (45).
10. The oil separator assembly (120) as claimed in claim 1, wherein said oil outlet pipes (128A, 128B) are configured to fluidly communicate with an oil reservoir provided at the bottom of the oil separator assembly (120) in fluid connection with the compressor oil inlet ports.
Dated this 22nd Day of November, 2024

_______________________________
MOHAN RAJKUMAR DEWAN, IN/PA – 25
of R.K. DEWAN & CO.
Authorized Agent of Applicant

TO,
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, AT MUMBAI