DESC:FIELD
The present disclosure generally relates to dehumidifiers. More particularly, the present disclosure relates to a thermoelectric dehumidifier for a transformer cable box.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Transformers are one of the most critical components in a power network, making them among the most expensive assets in electricity transmission and distribution. The cable boxes of transformers typically include bushings, support insulators and cable terminations. These items are subjected to moisture during their lifetime. For example, condensation may occur on the termination surface if the temperature of the termination surface is lower than the ambient air temperature in the cable box. Similarly, during monsoons, moisture may seep into the cable boxes. These moistures can lead to partial discharges in transformer cable boxes and subsequently failure of insulations.
It is essential to maintain minimum standard air clearances in the cable box, for example, between the phases, phase and earth, and the live metal parts. This is particularly important in cable boxes having MV or HV (22kV and 33kV) cable terminations so as to ensure equipment and personnel safety. Increase in humidity level inside the cable box may lead to undesirable events such as surface tracking, flashover and surge impulses, and the standard clearances may be insufficient to provide protection against such events.
Typically, most of the transformer cable boxes only prevent ingress of moisture into them. However, once condensation occurs in the cable box, there exists no means/mechanism of reducing the moisture.
Further, dehumidifiers, particularly compressor dehumidifiers, are generally used only in residential or industrial Heating Ventilation and Air Conditioning (HVAC) systems. Thermoelectric dehumidifiers are one of the candidate areas which have not been explored for use in electrical systems such as transformer cable boxes for removal of moisture.
These portable tailored dehumidifiers can fit into transformer cable box and can transport the excess moisture of transformer cable boxes to outside of the boxes.
Therefore, there is a need for a thermoelectric dehumidifier for a transformer cable box that alleviates the above mentioned problems.
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 a thermoelectric dehumidifier for a transformer cable box.
Another object of the present disclosure is to provide a thermoelectric dehumidifier for a transformer cable box that has an automatic cut in and cut off ability.
Still another object of the present disclosure is to provide a thermoelectric dehumidifier for a transformer cable box that includes a MODBUS interface to connect to a remote server such as a SCADA server.
Yet another object of the present disclosure is to provide a thermoelectric dehumidifier for a transformer cable box that facilitates continuous monitoring of the humidity level inside the cable box.
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 a thermoelectric dehumidifier for a transformer cable box. The thermoelectric dehumidifier comprises a water accumulation box, a cold side hear sink, a hot side heat sink, at least one Peltier module, an electronic controller, and a relay module. The cold side heat sink is accommodated within the water accumulation box. The hot side heat sink is mounted on the water accumulation box. The Peltier module is sandwiched between the cold side heat sink and the hot side heat sink. The Peltier module receives an electrical power and causes a side thereof in contact with the hot side heat sink to get hot and the other side thereof in contact with the cold side heat sink to get cold, upon receiving the electrical power.
The electronic controller is configured to receive a real-time sensed humidity value from a sensor and is further configured to compare the received real-time humidity value with a pre-set threshold value and generate a trigger signal when the sensed humidity value becomes less than or equal to the pre-set threshold value. The relay module is connected to the electronic controller. The relay module is configured to receive the trigger signal from the electronic controller and interrupt the supply of the electrical power to the Peltier module upon receiving the trigger signal.
In an embodiment, the dehumidifier comprises a first opening, configured above the hot side heat sink, for housing a heat dissipating fan to increase the heat dissipation rate of the hot side heat sink.
The dehumidifier comprises a control means for facilitating a user to set the threshold humidity value.
In an embodiment, the dehumidifier comprises a plurality of air inlet holes and a second opening. The air inlet holes are configured on one side of the water accumulation box in the vicinity of the cold side heat sink to facilitate entry of warm humid air therethrough into the water accumulation box. The second opening is configured on the other side of the water accumulation box to allow the air to be pulled out of the water accumulation box.
Advantageously, at least one shock absorber is provided at an operative bottom side of the dehumidifier to dampen the vibrations generated in the dehumidifier.
Advantageously, at least one anti-slip pad is provided at an operative bottom side of the dehumidifier to provide an optimum grip to the dehumidifier.
The dehumidifier comprises a water outlet configured on a side of the accumulation box to facilitate water accumulated due to the dehumidification process to flow out therefrom.
Advantageously, the dehumidifier comprises a communication interface configured to send the real-time humidity level values/data to a remote server for facilitating real time remote monitoring. The communication interface is selected from the group consisting of a wired connection, a wireless short-range connection, a wireless long-range connection, and a MODBUS connection.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A thermoelectric dehumidifier for a transformer cable box, of the present disclosure, will now be described with the help of the accompanying drawing, in which:
Figures 1A and 1B illustrate perspective side views of a thermoelectric dehumidifier for a transformer cable box of Figure 1, in accordance with the present disclosure;
Figure 1C illustrates a sectional view of the thermoelectric dehumidifier for a transformer cable box of Figure 1, in accordance with the present disclosure;
Figures 1D and 1E illustrate perspective isometric views of a Peltier module sandwiched between a hot side heat sink and a cold side heat sink of the thermoelectric dehumidifier of Figure 1, in accordance with the present disclosure;
Figure 2 illustrates a block diagram of an electrical circuit comprising an in-built sensor, an electronic controller, a relay module, and a Peltier module of the thermoelectric dehumidifier of Figures 1A and 1B, in accordance with the present disclosure;
Figure 3 illustrates a graph indicating humidity values recorded every hour for a pre-determined period within the transformer cable box with and without the presence of the thermoelectric dehumidifier of Figures 1A and 1B;
Figure 4A illustrates a bar graph showing average humidity levels inside the transformer cable box during rain with the thermoelectric dehumidifier of Figures 1A and 1B in ON condition;
Figure 4B illustrates a bar graph showing average temperatures inside and outside the transformer cable box during rain with the thermoelectric dehumidifier of Figures 1A and 1B in ON condition;
Figures 5A and 5B illustrate bar graphs of base level of relative humidity inside the transformer cable box during monsoon with and without the thermoelectric dehumidifier of Figures 1A and 1B; and
Figure 5C illustrates a bar graph indicating the number of instances of partial discharge in transformer during different financial years.
LIST OF REFERENCE NUMERALS
100 – Dehumidifier
102a – Hot side heat sink
102b – Cold side heat sink
104 – Electronic controller
106 – Housing/casing for heat dissipating fan
106a – Heat dissipating fan
108 – Water accumulation box
202 – Exhaust fan housing
204 – Water outlet
206 – Air inlet holes
300 – Electrical circuit
302 – Humidity sensor
304 – Relay module
306 – Peltier module
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.
When an element is referred to as being “mounted on”, “engaged to”, “connected to” or “coupled to” another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
Currently, there exists no means to monitor and control the moisture level inside transformer cable boxes. The ingress of moisture into the cable boxes can result into undesirable events such as electrical tracking, flashover, and surge impulses, which is not desired.
In order to address aforementioned issues, the present disclosure envisages a thermoelectric dehumidifier (hereinafter referred to as “dehumidifier 100”) for power transformer cable box. The dehumidifier 100 is now being described with reference to Figure 1A through Figure 5C.
Referring to Figures 1A to 2, the dehumidifier 100 comprises a water accumulation box 108, a cold side heat sink 102b, a hot side heat sink 102a, at least one Peltier module 306, an electronic controller 104, and at least one relay module 304. The cold side heat sink 102b is accommodated in the water accumulation box 108. The hot side heat sink 102a is mounted on the water accumulation box 108. The Peltier module 306 is sandwiched between the cold side heat sink 102b and the hot side heat sink 102a. The Peltier module 306 receives an electrical power and causes a side thereof in contact with the hot side heat sink 102a to get hot and the other side thereof in contact with the cold side heat sink 102b to get cold due to the Peltier effect, upon receiving the electrical power.
The electronic controller 104 is configured to receive power from a main power source. In an embodiment, the electronic controller 104 supplies the electrical power to the Peltier module 306. In another embodiment, the Peltier module 306 receives the electric power from an independent power source. The independent power source may be an AC source such as mains power supply or a DC source such as a battery. As shown in Figure 2, the electronic controller 104 is configured to receive a real-time sensed humidity value from the sensor 302 and is further configured to compare the received real-time humidity value with a pre-set threshold value and generate a trigger signal when the sensed humidity value becomes less than or equal to the pre-set threshold value. The relay module 304 is connected to the electronic controller 104. The relay module 304 is configured to receive the trigger signal from the electronic controller 104 and interrupt the supply of the electrical power to the Peltier module 306 upon receiving the trigger signal.
In an embodiment, the hot side heat sink 102a has a larger size compared to the cold side heat sink 102b.
In an embodiment, the dehumidifier 100 comprises a first opening 106, configured above the hot side heat sink 102a, for housing a heat dissipating fan 106a to increase the heat dissipation rate of the hot side heat sink 102a.
Advantageously, the dehumidifier 100 comprises a control means coupled to the electronic controller 104 for facilitating a user to set the threshold humidity value. The control means may be a knob or a switch with multiple settings.
Advantageously, the dehumidifier 100 comprises two Peltier modules 306 operated/controlled by a single electronic controller 104.
The electronic controller 104 may be implemented using one or more general-purpose processors, Field Programmable Gate Arrays (FPGAs), Programmable Logic Controllers (PLCs), Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), microprocessors, microcontrollers, or state machines. The controller 104 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. The controller 104 may be configured to retrieve data from and/or write data to a memory. The memory may be, for example, a random-access memory (RAM), a memory buffer, a hard drive, a database, an erasable programmable read only memory (EPROM), an electrically erasable programmable read only memory (EEPROM), a read only memory (ROM), a flash memory, a hard disk, a floppy disk, cloud storage, and/or so forth.
In an embodiment, the dehumidifier 100 comprises a plurality of air inlet holes 206 and a second opening 202 for housing an exhaust fan. The air inlet holes 206 are configured on one side of the water accumulation box 108 in the vicinity of the cold side heat sink 102b to facilitate entry of warm humid air therethrough into the water accumulation box 108. The second opening 202 configured on the other side of the water accumulation box 108 to allow the air to be pulled out of the water accumulation box 108.
Advantageously, at least one shock absorber is provided at an operative bottom side of the dehumidifier 100 to dampen the vibrations generated in the dehumidifier 100.
Advantageously, at least one anti-slip pad is provided at an operative bottom side of the dehumidifier 100 to provide an optimum grip to the dehumidifier 100.
In an embodiment, the dehumidifier 100 comprises a water outlet 204 configured on a side of the accumulation box 108 to facilitate water accumulated due to the dehumidification process to flow out therefrom.
Advantageously, the dehumidifier 100 comprises a communication interface configured to send the real-time humidity level data to a remote server, such as a central server such as a Supervisory Control and Data Acquisition (SCADA) system server for facilitating live/real-time remote monitoring. The communication interface is selected from the group consisting of a wired connection, a wireless short-range connection, a wireless long-range connection, and a MODBUS connection.
In an operative embodiment, the electronic controller 104 receives a real-time sensed humidity value from the in-built humidity sensor. When the sensed humidity value exceeds a pre-set threshold, the electronic controller 104 activates the relay module 304, which in turn establishes electrical connection between a power supply point and the Peltier module 306. Upon receiving the electrical power from the power supply, one side of the Peltier module 306 gets hot and the other side gets cold due to the Peltier effect. A warm humid air of the transformer cable box is pulled into the dehumidifier 100 through the inlet holes 206 by the exhaust fan that is provided at the back of the dehumidifier 100. The warm humid air first comes in contact with the cold side heat sink 102b which is in contact with the cold side of the Peltier module 306. This is where the dehumidification process takes place. The warm humid air condenses on the cold side heat sink 102b. The condensate from the cold side heat sink 102b drips down into the water accumulation box 108 below it. The air travels around the entire cold side heat sink 102b to facilitate dehumidification thereof. The dehumidified air then passes through the Peltier module 306 and is pulled past the hot side heat sink 102a which is in contact with the hot side of the Peltier module 306. The air exhausts out of the dehumidifier 100 as a warmer and dryer air. When the sensed humidity value becomes less than or equal to the pre-set threshold value, the electronic controller 104 sends a trigger signal to activate the relay module 306, which in turn interrupts the supply of electrical power to the Peltier module 306 to stop the dehumidification process. Thus, the dehumidifier has automatic cut in and cut off ability.
The present invention was implemented and tested by recording the values of humidity and temperature inside and outside the transformer cable box with and without the presence of the dehumidifier 100. A suitable value of the threshold humidity was selected/decided based on the analysis of the impact of ambient temperature and humidity on the temperature and humidity within the transformer cable box. Figure 3 shows a plot of humidity values recorded every hour for 23 hours within the transformer cable box with and without the presence of the dehumidifier 100. The temperatures and humidity were recorded and analyzed during rain conditions. Figure 4A shows average humidity levels inside and outside the transformer cable box during rain with the dehumidifier in ON condition. Similarly, Figure 4B shows average temperatures inside and outside the transformer cable box during rain with the dehumidifier in ON condition. Figures 5A and 5B illustrate bar graphs indicating base level of relative humidity inside the transformer cable box during monsoon with and without dehumidifier 100. Figure 5C illustrates a bar graph indicating the number of instances ‘n’ of partial discharge in transformer during different financial years from 2017-2021.
From the above data, it can be seen that the dehumidifier 100 successfully maintains the humidity value inside the transformer cable box within an acceptable range. Further, the dehumidifier 100 also keeps the average humidity inside the cable box at a lower value compared to the average ambient humidity and the average temperature inside the cable box at a higher value (desired condition) compared to the average ambient temperature. Similarly, the average relative humidity inside the transformer cable box is reduced when the dehumidifier is in ON state. The number of instances of partial discharge in transformer is also reduced to zero when the dehumidifier 100 is deployed.
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 herein above has several technical advantages including, but not limited to, the realization of a thermoelectric dehumidifier for a transformer cable box that:
• is low cost;
• has automatic cut in and cut off ability;
• includes a MODBUS interface to connect to a remote server such as a SCADA server; and
• facilitates continuous monitoring of the humidity level inside the cable box.
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.
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.
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. A thermoelectric dehumidifier (100) for a transformer cable box comprising:
a. a water accumulation box (108);
b. a cold side heat sink (102b) accommodated within said water accumulation box (108);
c. a hot side heat sink (102a) mounted on said water accumulation box (108);
d. at least one Peltier module (306) sandwiched between said cold side heat sink (102b) and said hot side heat sink (102a), wherein said Peltier module (306) is configured to receive an electrical power and cause a side thereof in contact with said hot side heat sink (102a) to get hot and the other side thereof in contact with said cold side heat sink (102b) to get cold, upon receiving the electrical power;
e. an electronic controller (104) configured to receive a real-time sensed humidity value from said sensor (302), and further configured to compare the received real-time humidity value with a pre-set threshold value and generate a trigger signal when the sensed humidity value becomes less than or equal to the pre-set threshold value; and
f. a relay module (304) connected to said electronic controller (104), said relay module (304) configured to receive said trigger signal from said electronic controller (104) and interrupt the supply of the electrical power to the Peltier module (306) upon receiving said trigger signal.
2. The dehumidifier (100) as claimed in claim 1, which comprises a first opening (106), configured above said hot side heat sink (102a), for housing a heat dissipating fan (106a) to increase the heat dissipation rate of said hot side heat sink (102a).
3. The dehumidifier (100) as claimed in claim 1, which comprises a control means for facilitating a user to set said threshold humidity value.
4. The dehumidifier (100) as claimed in claim 1, which comprises:
a. a plurality of air inlet holes (206) configured on one side of said water accumulation box (108) in the vicinity of the cold side heat sink (102b) to facilitate entry of warm humid air therethrough into said water accumulation box (108); and
a. a second opening (202), for housing an exhaust fan, configured on the other side of said water accumulation box (108) to allow the air to be pulled out of said water accumulation box (108).
5. The dehumidifier (100) as claimed in claim 1, wherein at least one shock absorber is provided at an operative bottom side of the dehumidifier (100) to dampen the vibrations generated in the dehumidifier (100).
6. The dehumidifier (100) as claimed in claim 1, wherein at least one anti-slip pad is provided at an operative bottom side of the dehumidifier (100) to provide an optimum grip to the dehumidifier.
7. The dehumidifier (100) as claimed in claim 1, which comprises a water outlet (204) configured on a side of said accumulation box (108) to facilitate water accumulated due to the dehumidification process to flow out therefrom.
8. The dehumidifier (100) as claimed in claim 1, which comprises a communication interface configured to send said real-time humidity level data to a remote server for facilitating real time remote monitoring.
9. The dehumidifier (100) as claimed in claim 1, wherein said communication interface is selected from the group consisting of a wired connection, a wireless short-range connection, a wireless long-range connection, and a MODBUS connection.