DESC:TECHNICAL FIELD
[001] The present invention relates to a method and a system of refrigerant leakage detection in a chiller.
BACKGROUND
[002] Generally, a chiller is used to chill water in an evaporator. Chillers are majorly classified into two types, namely air-cooled chillers, and water-cooled chillers. Water-cooled chillers are further classified into flooded type or direct expansion type chillers. Chiller water is passed through air handling units which condition the air for use in a building, mall etc. An evaporator in the chiller controls the temperature of the water by heat exchange with a refrigerant. The refrigerant circulates throughout the chiller by means of a refrigerant loop.
[003] Refrigerant leakage in the chiller, often hidden from view, is a critical issue with significant environmental, economic, and health implications. Apart from the environmental impact, refrigerant leakage also contributes to energy efficiency implications and financial consequences. Minimizing refrigerant emissions is a crucial component of broader efforts to combat climate change and protect the environment. Refrigerants, leaking out of equipment into the atmosphere, add to a building’s whole-life carbon emissions. The risk of such leakage varies depending on the type of refrigerant system installed, the quality of its installation, maintenance regime, refrigerant recovery, and disposal at the end of the equipment's life. The atmospheric damage that refrigerant leaks cause depends on the type of refrigerant used and its properties like global warming potential (GWP). An early detection of refrigerant leaks in cooling systems is a crucial task for maintaining environmental sustainability, reducing energy consumption. R-134a is predominantly used in chillers that are part of commercial segment and chillers containing higher volume of refrigerant. R-134a is a Hydrofluorocarbon (HFC) refrigerant that has a GWP of 1430. This means that one kilogram of R-134a contributes 1430 times as much to the greenhouse effect as one kilogram of CO2 within 100 years after release.
[004] Conventionally, it is known to employ refrigerant leakage sensors that enable detection of the refrigerant leakage. However, deploying such sensors in plant rooms where multiple chillers are installed, these sensors do not give indication of which chiller is facing leakage. With dirt and dust accumulation on the sensors, the results are inconsistent and incorrect alerts are provided. Refrigerant leak sensors used are also non retrofittable in existing chillers. Furthermore, installation of the conventional sensors is costly, requires complex wirings, and results are based on positional determination of the sensors and therefore fails to accurately detect the leakage.
[005] Therefore, there is a need to provide a method and a system of refrigerant leakage detection to solve one or more of the aforementioned problems.
SUMMARY
[006] Accordingly, an aspect of the present invention discloses a method of refrigerant leakage detection which enables early detection of refrigerant leakage without the use of expensive refrigerant leakage sensors, useable with any chiller system. The method comprises the steps of storing, by a controller, a plurality of predetermined values; determining, by the controller, a state of a compressor; determining, by the controller, a percentage and a quantity of refrigerant flowing in a refrigerant loop by determining a first and second series of simultaneous and parallel calculations based on a plurality of real-time calculated values obtained from a plurality of sensors and the plurality of predetermined values; and stopping the chiller if the calculated percentage of refrigerant flowing in the refrigerant loop is lower than a first condition determined based on the first series of calculations or greater than a second condition determined based on the second series of calculations defining low quantity of refrigerant flowing in the refrigerant loop.
[007] According to another aspect, the present invention discloses a system of refrigerant leakage detection which enables early detection of refrigerant leakage without the use of expensive refrigerant leakage sensors, useable with any chiller system.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
[008] The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which:
[009] Figure 1 illustrates a schematic diagram of a chiller system according to the present invention;
[010] Figure 2 illustrates a logic diagram associated with a method of refrigerant leakage detection, according to an exemplary aspect of the present invention;
[011] Figure 3 illustrates a flow chart showing a method of refrigerant leakage detection in a chiller, according to an exemplary embodiment of the present invention; and
[012] Figure 4 illustrates a controller of the system of a chiller, according to the exemplary embodiment of the present invention.
[013] Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to the other elements to help improve understanding of various exemplary embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference signs are used to depict the same or similar elements, features, and structures.
DETAILED DESCRIPTION
[014] While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail, a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspects of the invention to the embodiment illustrated.
[015] Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention. Embodiments of the present disclosure will now be described with reference to the accompanying drawings. Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to a person skilled in the art. Numerous details are set forth relating to specific components 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.
[016] In general, the present invention discloses a method and a system having a controller for refrigerant leakage detection in a chiller without leakage detection sensors. The controller is configured to calculate a percentage and quantity of refrigerant flowing in a refrigerant loop by determining first and second series of simultaneous and parallel calculations based on the plurality of real-time calculated values and the plurality of predetermined values and stops the chiller if the calculated percentage of refrigerant flowing in the refrigerant loop is lower than a first condition determined based on the first series of calculations or greater than a second condition determined based on the second series of calculations defining low quantity of refrigerant flowing in the refrigerant loop.
[017] 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. The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results. 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,” “made of” and “having,” are open ended transitional phrases.
[018] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention, for example of chiller, refrigerant referred in the description are provided for illustration purpose and understanding only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. The skilled person will be able to devise various types of chiller, refrigerants, sensors, type of controllers, although not explicitly described herein, embody the principles of the present invention. All the terms and expressions in the description are only for the purpose of understanding and nowhere limit the invention. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein may be made without departing from the scope of the invention. Terms like first, second, internal, external, inside, outside, plurality and the like are used to differentiate between objects having the same terminology and are in no way intended to represent a chronological order, unless where explicitly stated otherwise. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass equivalents thereof. Thus, while refrigerants, chiller, sensor, material, quantity, numbers, input values, temperatures, pressures, predetermined values, time intervals, have been disclosed, such components nowhere limit the invention and are provided for understanding of the invention. It will be appreciated that the embodiments may be manufactured with other design parameters and configurations as well and are not limited to those described herein above may be as per operational requirements by making necessary changes and is not limited to those described herein and nowhere limits the scope of the invention and are provided only for reference and for understating purpose of the invention. The structure and design of the system may vary accordingly as well.
[019] Figures 1-4 discloses a system (100), a method (200) and a flow chart (300) of refrigerant leakage detection without the use of a refrigerant leakage sensor. The system has a compressor (110), a condenser (120), an expansion valve (130), an evaporator / cooler (140) and an oil separator (150). A controller (400) is provided with a plurality of ports (404, 406, 408, 410, 412, 414). A plurality of sensors in communication with the controller (400) are positioned in the chiller at the plurality of ports (404, 406, 408, 410, 412, 414), configured for sensing a plurality of values. The plurality of sensors may be configured to sense a suction pressure, a discharge pressure, a leaving water temperature, a discharge temperature, a liquid temperature, and a current. The controller (400) is configured to calculate a discharge superheat, an evaporator approach, a full load current, a corrected suction pressure, a corrected liquid temperature, a corrected saturated liquid pressure, a corrected discharge superheat, and a percent of refrigerant based on the readings of the plurality of sensors.
[020] Referring Figure 1 illustrates the system (100) for refrigerant leakage detection in a chiller. According to an embodiment of the present invention, the chiller system shows a refrigerant circuit of a standard flooded water-cooled chiller comprising an arrangement of a compressor (110), a condenser (120), an electronic expansion valve (130), an evaporator (140) and an oil separator (150). The system (100) may include an electric motor for the compressor (110). The evaporator / cooler (140) may be a shell and tube type evaporator with flooded type of system. The evaporator (140) may be heat exchanging medium and is utilized for the cooling load which may be the flow of water to and from. The refrigerant is on the shell side of the evaporator and water in on the tube side of the evaporator (140). A suction line connects the evaporator (140) flooded type to the compressor (110) passing vaporized refrigerant from the evaporator (140) to the compressor (110), where the vapour is then compressed and discharged to condenser (120) via a discharge line with non-return valve. In system (100), low pressure refrigerant gas is compressed in the compressor into high pressure refrigerant vapour. The high-pressure refrigerant vapour then enters an oil separator (150) where oil gets separated and is returned to the compressors through Solenoid Valve SV2. It then enters the condenser (120) where it is converted into high pressure refrigerant liquid by heat exchange with Water. From Condenser (120) it is expanded by an expansion valve (130) to low pressure refrigerant liquid. It then again enters the evaporator (140) where heat exchange with water causes it to become low pressure refrigerant vapour. According to the embodiment, the condenser in the present invention may be a shell and tube type heat exchanger type, the condenser is a heat transfer vessel which condenses the compressed refrigerant vapour usually in shell side received from the compressor. The heat of condensation is rejected to condensing water which enters the condenser through a line and circulates through the tube contained in the shell and exists the condenser.
[021] Referring Figure 4, according to the embodiment, a controller (400) of the system (100) of refrigerant leakage detection in the chiller (not shown) without a refrigerant leakage sensor. The controller (400) with predefined instructions is interfaced to various inputs like (404, 406, 408, 410, 412, 414) and provides continuous performance monitoring on a display. A plurality of sensors (not shown) are in communication with the controller (400) and are positioned in the chiller. The plurality of sensors may be configured to sense a plurality of values. The controller (400) has a plurality of ports (404, 406, 408, 410, 412, 414). The ports (404, 406, 408, 410, 412, 414) receive a plurality of inputs from the sensors. The controller (400) of the disclosed embodiment has six input ports (404, 406, 408, 410, 412, 414) for receiving the plurality of inputs. It should be noted that the controller (400) can have any number of ports (404, 406, 408, 410, 412, 414) with functions other than receiving inputs from without limiting the scope of what is disclosed. The plurality of sensors may be configured to sense suction pressure, discharge pressure, a leaving water temperature, a discharge temperature, a liquid temperature, and a current. A first port (404) of the controller (400) receives a leaving water temperature value sensed by the sensors. The leaving water temperature value is a water temperature measured at an outlet of an evaporator (140) of the chiller system (100). A second port (406) of the controller (400) receives a suction pressure value sensed by the sensors. The suction pressure value is the pressure of a refrigerant measured at an input of a compressor (110) of the chiller system (100). A third port (408) of the controller (400) receives a discharge pressure value sensed by the sensors. The discharge pressure value is the pressure of the refrigerant measured at an output of the compressor (110) of the chiller system (100). Further, a fourth port (410) of the controller (400) receives a discharge temperature value sensed by the sensors. The discharge temperature value is a temperature of the refrigerant measured at the outlet of the compressor (110) of the chiller system (100). A fifth port (412) of the controller (400) receives a liquid temperature value sensed by the sensors. The liquid temperature value is the temperature of the refrigerant measured at an outlet of an expansion valve (130) of the chiller system (100). A sixth port (414) of the controller (400) receives a current value sensed by the sensors. The current value is an input current to the compressor (11) measured with the help of a current transformer.
[022] According to the exemplary embodiment, the controller (400) of the present disclosure is configured to store a plurality of predetermined values that includes but not limited to a first predetermined value, a predetermined electronic expansion valve value, a predetermined suction pressure value, a second predetermined value, and a predetermined discharge super heat value in a memory. It should be noted that the controller can store any other values without limiting the scope of what is disclosed. According to the exemplary embodiment the controller (400) stores the following values the first predetermined value which may be 85 percent, the predetermined electronic expansion valve value which may be 85 percent, the predetermined suction pressure value which may be 30 PSIG (pounds per square in gauge), the second predetermined value which may be 70 percent and the predetermined discharge superheat value which may be 30 degrees Fahrenheit. The electronic expansion valve value may be defined as the state of the electronic expansion valve in opening state or closed state to control the flow of refrigerant into the evaporator, ensuring the correct amount of refrigerant is delivered to maintain optimal cooling performance and efficiency.
[023] According to the exemplary embodiment, the controller (400) of the present disclosure is also configured to calculate a discharge superheat, an evaporator approach, a full load current, a corrected suction pressure, a corrected liquid temperature, a corrected sat liquid pressure, and a corrected discharge superheat based on inputs from the sensors. The above-mentioned values are then used for calculation of a percentage of refrigerant flowing through the refrigerant loop.
[024] According to the exemplary embodiment, the discharge super heat (DSH) is calculated according to the following equation:
DSH= DT- Saturated DT
where,
DT= discharge temperature; Saturated DT= saturated discharge temperature from the refrigerant temperature chart; Saturated Discharge Temperature is calculated by the refrigerant temperature chart for the Refrigerant (R134a). The difference between the discharge temperature and the saturated discharge temperature is the discharge super heat.
[025] According to the exemplary embodiment, the evaporator approach (Evap App) is calculated according to the following equation:
Evap App= water out – Saturated ST
where,
water out = leaving water temperature value; Saturated ST = saturated suction temperature; Evaporator approach is the difference between the leaving water temperature value and saturated suction temperature value.
[026] According to the exemplary embodiment, the full load current (FLA) is calculated by the running current. The full load current is the percentage at which the chiller is running.
[027] The corrected suction pressure (Corr SP) is calculated by the following equation:
Corr SP =
SP - (MIN (Water Out, 50)-Design Wat Out) *A1-(FLA%-100)/100 * A2
where,
SP = suction pressure; Water Out = leaving water temperature; Design Water Out = 44 degrees Fahrenheit; A1 = Water Outlet Correction Factor (1.05); FLA% = full load current; A2 = Load Correction Factor (8)
[028] According to the exemplary embodiment, the corrected liquid temperature (Corr LT) is calculated by the following equation:
Corr LT = LT - (Water Out-Design Water Out)
Where,
LT = liquid temperature value; Water Out = leaving water temperature; Design Water Out = 44 degrees Fahrenheit; The corrected saturated liquid temperature (Corr LP) is saturated pressure at the corrected liquid temperature.
[029] The corrected discharge superheat (Corr DSH) is calculated by the following equation:
Corr DSH = DSH+(100-FLA%)/100*A3
Where,
DSH = discharge superheat; FLA% = full load current; A3 = Discharge superheat Correction Factor (5)
[030] Refrigerant percentage (Gas %) is calculated by the following equation:
Gas% = A4*Corr SP+A5*Corr Sat LP+A6*Corr DSH +A7
Where,
A4 = Corr Suction Pressure multiplier (1.875); Corr SP = corrected suction pressure
A5 = Corr Liquid Temperature multiplier (0.375); Corr Sat LP = corrected saturated liquid pressure; A6 = Corr Discharge Superheat multiplier (-1.2); Corr DSH = Corrected discharge superheat; A7 = Constant (40.6)
[031] According to the exemplary embodiment, the controller (400) is configured to sensing a plurality of values from the sensors and determining a plurality of real-time calculated values; calculate a percentage of refrigerant flowing in a refrigerant loop based on a determined state of the compressor (110); determine a first and second series of simultaneous and parallel calculations based on the plurality of real-time calculated values and the plurality of predetermined values to alert or indicate a real-time state of the chiller; and stopping the chiller if the calculated percentage of refrigerant flowing in the refrigerant loop is lower than a first condition determined based on the first series of calculations or greater than a second condition determined based on the second series of calculations defining low quantity of refrigerant flowing in the refrigerant loop. The first series of calculations may be defined by the percentage of refrigerant flowing in the refrigerant loop and the second series of calculations may be defined by the quantity of the refrigerant flowing in the refrigerant loop, determining how less/more the refrigerant is flowing in the refrigerant loop.
[032] According to an exemplary aspect, the present invention, referring to Figure 2 discloses a method (200) of refrigerant leakage detection without a refrigerant leakage detection sensor in a chiller. According to the present invention, the chiller may be a flooded type of chiller. The chiller may be an air-cooled chiller, or a water-cooled chiller but not limited thereto. The refrigerant in the chiller may be R-134a but not limited thereto. The method (200) of refrigerant leakage detection without a refrigerant leakage sensor includes the steps of (205) storing, by the controller in a memory, a plurality of predetermined values that includes but not limited to a first predetermined value, a predetermined electronic expansion valve value, a predetermined suction pressure value, a second predetermined value, and a predetermined discharge super heat value. The method (200) further comprises the step of (210) detecting /determining, by a controller, a state of the compressor i.e., whether a compressor of the chiller is in a startup mode. The controller ignores a refrigerant leak condition when the compressor is identified to be in the startup mode. Now, the method (200) includes further steps of (215) determining, by the controller, a percentage of refrigerant flowing in a refrigerant loop. The controller calculates the percentage and the quantity of refrigerant flowing in a refrigerant loop by determining a first and second series of simultaneous and parallel calculations based on a plurality of real-time calculated values obtained from a plurality of sensors and the plurality of predetermined values. This calculation step is performed by the first series of calculations (220a) wherein comparing, a calculated value of the percentage of refrigerant with the first predetermined value occurs and the controller further performs comparing, the calculated value of the percentage of refrigerant with the second predetermined value. Simultaneously, the controller is configured to perform a second series of calculations (220b) wherein simultaneously comparing, by the controller, a real-time electronic expansion calculated valve with the electronic expansion valve predetermined value occurs. Now, the method (200) within the first series of calculations (220a) includes the following steps of (225) alerting or indicating a real-time state of the chiller based on the first and second series determined values. The controller alerts with a chiller display, when the percentage of refrigerant drops below the first predetermined value else, indicating the real-time state of the chiller includes indication of a normal running state. Next the method (200) within the first series of calculations (220a) includes the steps of (230) comparing, by the controller, the percentage of refrigerant with a second predetermined value. The controller determines if a first condition is stratified i.e., the first condition may be defined as the condition of the chiller having the calculated percentage of refrigerant below the first predetermined value and further if the compared value of the percentage of refrigerant is lower than the second predetermined value. If the first condition is satisfied, the controller at step (260) stops the chiller and declares a refrigerant leakage. Now, the controller is configured to simultaneously calculate the second series of calculations (220b) having the steps of (240) determining if the electronic expansion valve is at a stage greater than the electronic expansion valve predetermined. If the determined value is true, the controller performs the step of (245) wherein the controller compares a real-time suction pressure calculated value with the predetermined suction pressure value to determine if the real-time suction pressure calculated value is greater than the predetermined suction pressure value. The second series of calculations (220b) determine the low quantity of refrigerant flowing in the loop. If the determined value is true, the controller performs the step of (250), wherein the controller compares a real-time discharge superheat calculated value with the predetermined discharge superheat value to determine if the real-time discharge superheat calculated value is greater than the predetermined discharge superheat value. If the controller determines that the all the three values at steps (240), (245) and (250) are true then the controller determines that the second condition is satisfied i.e., the second condition may be defined as a stage of chiller having electronic expansion valve greater than the electronic expansion valve predetermined, the suction pressure value is greater than the predetermined suction pressure value, and the discharge superheat value is greater than the predetermined discharge superheat value. When the controller determines that the second condition is satisfied, the controller performs stopping of the chiller and declaring an error of “Refrigerant leakage”, on the chiller display. i.e., the controller is configured to stop (260) the chiller when the percentage of refrigerant satisfies the first series of calculations (220a) or when the percentage of refrigerant satisfies the second series of calculations (220b).
[033] In another exemplary aspect of the present invention, a system for refrigerant leakage detection in a flooded type of chiller without a refrigerant leakage sensor is provided, the system includes a controller configured to store a first predetermined value, a predetermined electronic expansion valve value, a predetermined suction pressure value, a second predetermined value, and a predetermined discharge super heat value. The system also includes a plurality of sensors in communication with the controller positioned in the chiller, configured for sensing a plurality of values.
[034] According to the exemplary embodiment, the controller is configured to calculate a discharge superheat, an evaporator approach, a full load current, a corrected suction pressure, a corrected liquid temperature, a corrected saturated liquid pressure, a corrected discharge superheat, and a percent of refrigerant based on the readings of the plurality of sensors. According to the exemplary embodiment, the plurality of sensors are configured to sense a suction pressure, a discharge pressure, a leaving water temperature, a discharge temperature, a liquid temperature, and a current in the chiller.
[035] Referring Figure 3, illustrates a flow chart (300) of the steps of the method of refrigerant leakage detection without the use of a refrigerant leakage sensor according to the exemplary embodiment of the present invention. At step (302), the process starts. At step (305), the controller detects whether the compressor of the chiller is in startup mode. When the chiller is in a startup mode the controller ignores the refrigerant leakage condition at step (310). At step (315), the controller calculates a percentage of the refrigerant flowing in a refrigerant loop. Now, to determine the percentage of the refrigerant flowing in the refrigerant loop, the controller performs simultaneous first and second series of calculations parallelly. In the first series of calculations at step (320a), the controller compares the calculated percentage of refrigerant with a predetermined first value. At Step (325a), if the percentage of refrigerant is below the first predetermined value, the controller alerts with the help of a chiller display else, the chiller display remains silent, and the chiller runs normally. Then if the controller proceeding further at step (330a) compares the calculated percentage of refrigerant with a second predetermined value. Now, at Step (340) the controller stops the chiller when the calculated percentage of refrigerant drops below the second predetermined value.
[036] Now, the Controller again referring back to step (315), in the second series of calculations at step (320b) compares an electronic expansion valve value with a predetermined electronic expansion valve value. If the electronic expansion valve value is greater than predetermined value defining by state of opening or closing of the electronic expansion valve, the controller proceeds to step (325b) wherein the controller compares a suction pressure value with a predetermined suction pressure value else, the controller indicates that the chiller runs normally. If the compared suction pressure value is greater than the predetermined suction pressure value, the controller proceeds to step (330b) wherein the controller compares a discharge superheat value with a predetermined discharge superheat value else, the controller indicates that the chiller runs normally. Now, if the compared discharge superheat value is greater than the predetermined discharge superheat value, the controller stops the chiller else, the controller indicates that the chiller runs normally. Therefore, the controller stops the chiller if the steps conditions at (320b), (325b), (330b) are satisfied or the condition at step (330a) is satisfied i.e., the controller stops the chiller when the calculated percentage of refrigerant drops below the second predetermined value or when the discharge superheat value is greater than the predetermined discharge super heat value. The controller declares an error of “Refrigerant leakage” at step (340) and the process ends at step (342).
[037] According to the embodiment, the disclosed method provides a way of refrigerant leakage detection in the chiller without the use of expensive refrigerant leakage sensors. The disclosed method of refrigerant leakage detection without the use of a refrigerant leakage sensor is retrofittable to any chiller. The disclosed method of refrigerant leakage detection ensures the refrigerant leakage may be detected even in plant rooms where multiple chiller systems are installed. The method for refrigerant leakage provides environmental benefits by stopping the chiller by early detection of refrigerant leakage. With the teachings of the present invention, there is no requirement for complex wirings, connections for the sensors and there is no requirement of determining the position of the leakage detection sensors. Therefore, the present invention negates the requirement of additional sensors for refrigerant leakage detection and is economical. With the teachings of the present invention, as the percentage of refrigerant flowing is calculated virtually, with only the available sensors and no refrigerant leakage detection sensors, wirings / connections are less and therefore easy to work in all conditions.
[038] There have been described and illustrated herein several embodiments of an exemplary implementation of the system (100) and method (200) of refrigerant leakage detection in a chiller. It will also be apparent to a skilled person that the embodiments described above are specific examples of a single broader invention, which may have greater scope than any of the singular descriptions taught. There may be many alterations made in the description without departing from the scope of the invention. The present invention is simple in construction and design, integrated, cost effective and easy to manufacture and assemble, and can be integrated with existing chiller retro fittingly. The manufacturing and the operating process of the chiller with desired components, temperatures, values, pressures, type of refrigerant, capacity of components, type of components, and materials nowhere limit the invention and are provided for an understanding of the invention and may be employed depending upon the operational requirements by making necessary changes that are within the scope. Further, the figures are only for reference and understanding the purpose of the invention and do not have a limitation effect in the present application. The present invention has been described in the context method and system for refrigerant leakage detection in a flooded-type chiller without leakage detection sensors, however the method and systems can be adapted to different refrigerant systems. The present invention has been described in the context of a control fuzzy logic for refrigerant leakage detection in a flooded-type chiller without leakage detection sensors. However, the fuzzy logic of the present invention can be used in any type of refrigeration system. To use the control logic in other types of refrigeration systems, some changes may have to be made to the membership functions and the sensor information that is used by the control logic to account for the particular configuration of the system to which the control logic is being applied.
[039] While particular embodiments of the invention have been described, it is not intended that the invention be limited to the configuration disclosed thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise not restrictive to the terminology described herein above. Any discussion of embodiments 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.

,CLAIMS:
1. A method (200) of refrigerant leakage detection in a chiller without a refrigerant leakage detection sensor, the method (200) comprising the steps of:
storing, by a controller, a plurality of predetermined values;
determining, by the controller, a state of a compressor;
determining, by the controller, a percentage and a quantity of refrigerant flowing in a refrigerant loop by determining a first and second series of simultaneous and parallel calculations based on a plurality of real-time calculated values obtained from a plurality of sensors and the plurality of predetermined values; and
stopping the chiller if the calculated percentage of refrigerant flowing in the refrigerant loop is lower than a first condition determined based on the first series of calculations or greater than a second condition determined based on the second series of calculations defining low quantity of refrigerant flowing in the refrigerant loop.

2. The method (200) as claimed in claim 1, wherein the method (200) further comprising the step of alerting or indicating a real-time state of the chiller based on the first and second series determined values.

3. The method (200) as claimed in claim 1 or 2, wherein the plurality of predetermined values stored includes a first predetermined value, a predetermined electronic expansion valve value, a predetermined suction pressure value, a second predetermined value, and a predetermined discharge super heat value.

4. The method (200) as claimed in anyone of the preceding claims 1-3, wherein the step of determining the state of the compressor includes determining if the compressor is in a startup mode and ignoring a refrigerant leak condition when the compressor is in the startup mode.

5. The method (200) as claimed in anyone of the preceding claims 1-4, wherein the first series of calculations includes the steps of:
comparing, by the controller, the calculated value of the percentage of refrigerant with the first predetermined value; and
comparing, by the controller, the calculated value of the percentage of refrigerant with the second predetermined value.

6. The method (200) as claimed in anyone of the preceding claims 1-5, wherein the second series of calculations include the steps of:
comparing, by the controller, a real-time electronic expansion calculated valve with the electronic expansion valve predetermined value;
comparing, by the controller, a real-time suction pressure calculated value with the predetermined suction pressure value; and
comparing, by the controller, a real-time discharge superheat calculated value with the predetermined discharge superheat value.

7. The method (200) as claimed in anyone of the preceding claims 1-6, wherein the step of alerting the real-time state of the chiller includes alerting, with a chiller display, when the calculated percentage of refrigerant drops below the first predetermined value and indicating the real-time state of the chiller includes indication of a normal running state.

8. The method (200) as claimed in anyone of the preceding claims 1-7, wherein the first condition includes determining by the controller if the calculated percentage of refrigerant is lower than the first predetermined value and the second predetermined value.

9. The method (200) as claimed in anyone of the preceding claims 1-8, wherein the second condition includes determining by the controller if the real-time electronic expansion calculated valve is greater than the electronic expansion valve predetermined, the real-time suction pressure calculated value is greater than the predetermined suction pressure value, and the real-time discharge superheat calculated value is greater than the predetermined discharge superheat value defining low quantity of refrigerant flowing in the refrigerant loop.

10. The method (200) as claimed in anyone of the preceding claims 1-9, wherein the first predetermined value is 85%, the predetermined electronic expansion valve value is 85%, the predetermined suction pressure value is 30 PSIG (pounds per square in gauge), the second predetermined value is 70% and the predetermined discharge superheat value is 30 degrees Fahrenheit.

11. A system (100) of refrigerant leakage detection in a chiller without a refrigerant leakage detection sensor, the system (100) comprising:
a compressor (110) to compress a refrigerant to a desired temperature and pressure;
a condenser (120) to obtain a high-pressure refrigerant liquid;
an electronic expansion valve (130) to expand the high-pressure refrigerant liquid to a low-pressure refrigerant liquid;
an evaporator (140) to obtain a low-pressure refrigerant vapour;
an oil separator (150) to separate an oil from the refrigerant exiting from the compressor (110);
a controller (400) configured to store a plurality of predetermined values in a memory;
a plurality of sensors in communication with the controller (400) positioned in the chiller, said controller (400) is configured for:
sensing a plurality of values from the sensors and determining a plurality of real-time calculated values;
calculate a percentage and a quantity of refrigerant flowing in a refrigerant loop based on a determined state of the compressor (110);
determine a first and second series of simultaneous and parallel calculations based on the plurality of real-time calculated values and the plurality of predetermined values to alert or indicate a real-time state of the chiller; and
stopping the chiller if the calculated percentage of refrigerant flowing in the refrigerant loop is lower than a first condition determined based on the first series of calculations or greater than a second condition determined based on the second series of calculations defining low quantity of refrigerant flowing in the refrigerant loop.

12. The system (100) as claimed in claim 11, wherein the plurality of values from the sensors includes a suction pressure, a discharge pressure, a leaving water temperature, a discharge temperature, a liquid temperature, and a current.

13. The system (100) as claimed in claim 11 or 12, wherein, the plurality of real-time calculated values includes a discharge superheat, an evaporator approach, a full load current, a corrected suction pressure, a corrected liquid temperature, a corrected sat liquid pressure, and a corrected discharge superheat based on real-time values determined from the sensors.