REFRIGERANT CIRCUIT FOR COOLING A VFD UNIT OF AN AIR CONDITIONING SYSTEM

Abstract

A refrigerant circuit for cooling a Variable Frequency Drive (VFD) unit of an air conditioning system includes a condenser for condensing refrigerant vapor. A heat sink includes a supply conduit assembly adapted to receive a first portion of a subcooled refrigerant fluid from the condenser and a discharge conduit assembly adapted to discharge a superheated refrigerant vapor to an accumulator. The subcooled refrigerant fluid transitions to the superheated refrigerant vapor upon absorbing heat from the VFD unit thermally coupled to the heat sink. The accumulator supplies the superheated refrigerant vapor to a compressor. An expansion valve expands a second portion of the condensed refrigerant fluid. An evaporator evaporates the expanded second portion of the refrigerant fluid. A compressor compresses the evaporated refrigerant vapor from the evaporator and the superheated refrigerant vapor received from the accumulator.

Description

FIELD OF THE INVENTION

The disclosure generally relates to cooling mechanisms for sub-components of air conditioning assemblies. More particularly, the disclosure relates to a refrigerant circuit for improved temperature management of the sub-components, such as a Variable Frequency Drive (VFD) unit of an air conditioning system.

BACKGROUND

Heating ventilation and air conditioning (HVAC) systems are typically designed to operate at peak loads, which occur during short periods throughout the year. One of the most effective ways to improve energy efficiency of HVAC systems installed in buildings is to utilize variable frequency drives (VFDs). These are widely used in the HVAC field, including fan motors, pumps, compressors, etc. The VFD adjusts the speed of one or more motors based on the system load and operation schedule, resulting in a significant cut in energy consumption. Most VFDs have high efficiency, usually ranging between 93-98 percent. The energy losses in such VFD systems are mostly through heat dissipation (2 to 7 percent), with the remaining energy being lost in the form of heat or mechanical losses. Generally, mechanical losses in VFD systems through heat dissipation from essential components, such as power modules like insulated gate bipolar transistors (IGBTs) of VFD circuit units, are high. An improved cooling solution for such high heat dissipating power modules is therefore desirable for better thermal performance.

Traditionally, cooling mechanisms utilizing mechanical fins defined on variable frequency drive (VFD) mounting platforms have been used to maintain lower operating temperatures. These VFD mounting platforms are then housed within base pans or control boxes that are enclosures isolating the VFD from the other working components of an air conditioning system. However, with increasingly complex and advanced circuits utilizing microprocessors, insulated-gate bipolar transistors (IGBTs), and the like, the cooling supplied by traditional fins alone is insufficient to effectively remove heat from the electronic components. As such, solutions that incorporate fans in addition to the provision of fins have been proposed. However, the major drawback of such solutions is the minimal space available for the enclosures, base pans, or control boxes housing the VFD. For instance, in an outdoor unit of a VFD air conditioning system, the provision of axially mounted fans restricts the space available for the fins of the VFD mounting platform. An alternative solution, which provides improved cooling of the VFD within the limited space, is therefore desirable.

Another major drawback in existing variable frequency drive (VFD) systems include the generation of localized hotspots. Typically, the individual control modules include a plurality of electronic components positioned near each other. Moreover, several such control modules may be collectively positioned within a small area causing an increase in temperature only within the small area. In contrast, areas of the VFD mounting platform away from the control modules have lower temperatures. In the case of outdoor units, when exposed to ambient temperatures that are high during summer, the control modules are prone to irreparable damage due to exposure to extreme temperatures. Existing cooling solutions utilizing fans and fins fail to equitably distribute temperature over the entire VFD mounting platform and therefore increase the possibility of damaging the control modules. An alternative solution, which provides improved cooling of the VFD while preventing the generation of localized hotspots, is therefore desirable.

SUMMARY

This summary is provided to introduce a selection of concepts in a simplified format that are further described in the detailed description of the disclosure. This summary is not intended to identify key or essential inventive concepts of the disclosure, nor is it intended for determining the scope of the disclosure.

A refrigerant circuit for cooling a Variable Frequency Drive (VFD) unit of an air conditioning system, is disclosed. The refrigerant circuit includes a condenser for condensing refrigerant vapor. A heat sink includes a supply conduit assembly and a discharge conduit assembly. The supply conduit assembly is adapted to receive a first portion of a subcooled refrigerant fluid from the condenser and the discharge conduit assembly is adapted to discharge a superheated refrigerant vapor to an accumulator such that the subcooled refrigerant fluid transitions to the superheated refrigerant vapor upon absorbing heat from the VFD unit thermally coupled to the heat sink. The accumulator is adapted to supply the superheated refrigerant vapor to a compressor. An expansion valve expands a second portion of the subcooled refrigerant fluid. An evaporator evaporates the expanded second portion of the subcooled refrigerant fluid and a compressor compresses the evaporated refrigerant vapor from the evaporator and the superheated refrigerant vapor received from the accumulator.

In one or more embodiments, the refrigerant circuit also includes at least one valve for at least one of selectively preventing and selectively allowing flow of the first portion of the subcooled refrigerant fluid to the heat sink.

In one or more embodiments, the heat sink includes a base, a plurality of heat passages, the supply conduit assembly, and the discharge conduit assembly. A plurality of heat passages is defined in the base. Each of the plurality of heat passages extends from an outlet defined proximal to a high temperature region of the base towards an inlet defined proximal to a low temperature region of the base. Each of the plurality of heat passages includes at least one evaporator section proximal to the high temperature region and at least one condenser section proximal to the low temperature region. The at least one condenser section is in fluid communication with the at least one evaporator section, such that the subcooled refrigerant fluid in the at least one condenser section transitions to the superheated refrigerant vapor upon passing through the at least one evaporator section. The supply conduit assembly is in fluid communication with a corresponding inlet of a heat passage from the plurality of heat passages. The discharge conduit assembly is in fluid communication with a corresponding outlet of a heat passage from the plurality of heat passages.

In one or more embodiments, the heat sink includes a base, a plurality of heat pipes, the supply conduit assembly, and the discharge conduit assembly. The base includes a second face opposite to the first face and a plurality of fins disposed on the second face and extending from a high temperature region of the base. The plurality of heat pipes are thermally coupled to the base and extend from the outlet defined proximal to the high temperature region of the base towards the inlet defined proximal to the low temperature region of the base. Each of the plurality of heat pipes includes the at least one evaporator section proximal to the high temperature region and the at least one condenser section proximal to the low temperature region. The at least one condenser section is in fluid communication with the at least one evaporator section such that the subcooled refrigerant fluid in the at least one condenser section transitions to the superheated refrigerant vapor upon passing through the at least one evaporator section. The supply conduit assembly is adapted to be in fluid communication with a corresponding inlet of a heat pipe from the plurality of heat pipes. The discharge conduit assembly is adapted to be in fluid communication with a corresponding outlet of a heat pipe from the plurality of heat pipes.

In one or more embodiments, the supply conduit assembly includes a first diverter element adapted to connect at least one first header conduit with a plurality of first branch conduits for supplying the subcooled refrigerant fluid. Each of the plurality of first branch conduits is adapted to be in fluid communication with at least one of a corresponding inlet of a heat pipe from the plurality of heat pipes and a corresponding inlet of a heat passage from the plurality of heat passages.

In one or more embodiments, the discharge conduit assembly includes a second diverter element adapted to connect at least one second header conduit with a plurality of second branch conduits for receiving the superheated refrigerant vapor. Each of the plurality of second branch conduits is adapted to be in fluid communication with at least one of a corresponding outlet of a heat pipe from the plurality of heat pipes and a corresponding outlet of a heat passage from the plurality of heat passages.

In one or more embodiments, the VFD unit is mounted on a first face of the base of the heat sink. The VFD unit includes a plurality of control modules such that at least one control module from the plurality of control modules is thermally coupled to at least one of the at least one evaporator section of a corresponding heat passage from the plurality of heat passages and the at least one evaporator section of a corresponding heat pipe from the plurality of heat pipes.

In one or more embodiments, the first diverter element is adapted to receive the subcooled refrigerant fluid from the condenser.

In one or more embodiments, the second diverter element is adapted to supply the superheated refrigerant vapor to the accumulator.

In one or more embodiments, the subcooled refrigerant fluid in the first diverter element transitions to the superheated refrigerant vapor in the second diverter element upon absorbing heat from the Variable Frequency Drive (VFD) unit mounted on a portion of the base corresponding to at least one of the at least one evaporator section of the plurality of heat pipes and the at least one evaporator section of the plurality of heat passages.

In one or more embodiments, the at least one evaporator section and the at least one condenser section are disposed vertically along a longitudinal axis Y-Y′ of the base to form at least one of an I-shaped heat pipe and an I-shaped heat passage.

In one or more embodiments, the at least one evaporator section is disposed vertically along a longitudinal axis Y-Y′ of the base and the at least one condenser section is disposed horizontally along a lateral axis X-X′ of the base to collectively form at least one of an L-shaped heat pipe and an L-shaped heat passage.

In one or more embodiments, the at least one evaporator section and the at least one condenser section are disposed horizontally along a lateral axis X-X′ of the base and separated by a connecting section to collectively form at least one of a C-shaped heat pipe and a C-shaped heat passage.

In one or more embodiments, the connecting section comprises at least one sub section.

A refrigerant circuit for cooling the Variable Frequency Drive (VFD) unit of an outdoor unit of the air conditioning system, is disclosed. The refrigerant circuit includes the condenser for condensing refrigerant vapor. The outdoor unit includes the heat sink for receiving the first portion of the subcooled refrigerant fluid from the condenser. The heat sink includes the supply conduit assembly adapted to receive the first portion of the subcooled refrigerant fluid from the condenser and the discharge conduit assembly adapted to discharge the superheated refrigerant vapor to the accumulator. The subcooled refrigerant fluid transitions to the superheated refrigerant vapor upon absorbing heat from the VFD unit thermally coupled to the heat sink. The accumulator is adapted to supply the superheated refrigerant vapor to the compressor. The expansion valve expands the second portion of the condensed refrigerant fluid. The evaporator evaporates the expanded second portion of the refrigerant fluid. The compressor compresses the evaporated refrigerant vapor from the evaporator and the superheated refrigerant vapor received from the accumulator.

In one or more embodiments, the outdoor unit includes a housing, the heat sink mounted along a portion of the housing, and the VFD unit. The heat sink includes the first diverter element adapted to connect the at least one first header conduit with a plurality of first branch conduits for supplying the subcooled refrigerant fluid. Each of the plurality of first branch conduits is adapted to be in fluid communication with at least one of a corresponding inlet of a heat pipe from the plurality of heat pipes and a corresponding inlet of a heat passage from the plurality of heat passages. The heat sink includes the second diverter element adapted to connect the at least one second header conduit with the plurality of second branch conduits for receiving the superheated refrigerant vapor. Each of the plurality of second branch conduits is adapted to be in fluid communication with at least one of a corresponding outlet of a heat pipe from the plurality of heat pipes and a corresponding outlet of a heat passage from the plurality of heat passages. The VFD unit, mounted on the first face of the base of the heat sink, includes a plurality of control modules, such that at least one control module from among the plurality of control modules is thermally coupled to at least one of the at least one evaporator section of a corresponding heat pipe from the plurality of heat pipes and the at least one evaporator section of a corresponding heat passage from among the plurality of heat passages.

In one or more embodiments, the first face of the base and corner portions of the housing adjacent to the first face of the base collectively define a secondary internal space enclosing the VFD unit.

In one or more embodiments, the second face and portions of the housing excluding the corner portions adjacent to the first face of the base define a primary internal space.

In one or more embodiments, the plurality of fins protrudes into the primary internal space housing an axial fan.

In one or more embodiments, the subcooled refrigerant fluid in the first diverter element transitions to the superheated refrigerant vapor in the second diverter element upon absorbing heat from the VFD unit mounted on at least one of the at least one evaporator section of a corresponding heat pipe from the plurality of heat pipes and the at least one evaporator section of a corresponding heat passage from among the plurality of heat passages.

To further clarify the advantages and features of the method and the system, a more particular description of the method and the system will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawing. It is appreciated that these drawings depict only typical embodiments of the disclosure and are therefore not to be considered limiting its scope. The disclosure will be described and explained with additional specificity and detail with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

FIG. 1A exemplarily illustrates a schematic diagram depicting a refrigerant circuit of an air conditioning system, according to one or more embodiments of the disclosure;

FIG. 1B exemplarily illustrates a schematic diagram depicting the refrigerant circuit, according to one or more embodiments of the disclosure;

FIG. 1C exemplarily illustrates a front perspective view of a heat sink, according to one or more embodiments of the disclosure;

FIG. 2A exemplarily illustrates a front perspective view of the heat sink, according to one or more embodiments of the disclosure;

FIG. 2B exemplarily illustrates a rear perspective view of the heat sink, according to one or more embodiments of the disclosure;

FIG. 2C exemplarily illustrates a front planar view of the heat sink, according to one or more embodiments of the disclosure;

FIG. 3A exemplarily illustrates a top view of an outdoor unit showing the heat sink, according to one or more embodiments of the disclosure;

FIG. 3B exemplarily illustrates a top view of the heat sink with a variable frequency drive (VFD) unit mounted on the heat sink, according to one or more embodiments of the disclosure;

FIG. 4A exemplarily illustrates a perspective view of an embodiment of the heat sink with I-shaped heat pipes, according to one or more embodiments of the disclosure;

FIG. 4B exemplarily illustrates a perspective view of another embodiment of the heat sink with C-shaped heat pipes, according to one or more embodiments of the disclosure; and

FIG. 4C exemplarily illustrates a perspective view of yet another embodiment of the heat sink with S-shaped heat pipes, according to one or more embodiments of the disclosure.

Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve understanding of aspects of the disclosure. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the disclosure so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

DETAILED DESCRIPTION

For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the various embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the disclosure as illustrated therein being contemplated as would normally occur to one skilled in the art to which the disclosure relates.

It will be understood by those skilled in the art that the foregoing general description and the following detailed description are explanatory of the disclosure and are not intended to be restrictive thereof.

Reference throughout this specification to “an aspect”, “another aspect” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. Thus, appearances of the phrase “in an embodiment”, “in another embodiment”, “some embodiments”, “one or more embodiments” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by “comprises . . . a” does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components.

Embodiments of the disclosure will be described below in detail with reference to the accompanying drawings.

FIG. 1A exemplarily illustrates a schematic diagram depicting a refrigerant circuit 100 of an air conditioning system, according to one or more embodiments of the disclosure. FIG. 1B exemplarily illustrates a schematic diagram depicting the refrigerant circuit 100 according to one or more embodiments according to the disclosure. In the illustrated embodiment, the refrigerant circuit 100 may include, but is not limited to a condenser 108, an accumulator 109, a compressor 110, an expansion valve 111, an evaporator 112, and a heat sink 113. Additional valves or regulating devices for directing the flow of a refrigerant or regulating a flow rate of the refrigerant may also be included in the refrigerant circuit 100 without departing from the scope of the disclosure. For example, a reverse valve assembly 116 may be provided to reverse refrigerant flow when the air conditioning system alternates between a heating cycle and a cooling cycle. The condenser 108 receives refrigerant vapor from the compressor 110. The compressor 110 used in such air conditioning systems may include, but are not limited to, reciprocating compressors, rotary compressors, scroll compressors, screw compressors, centrifugal compressors, and the like. The compressor 110 of the refrigerant circuit 100, disclosed herein, compresses the refrigerant vapor, which increases pressure and temperature of the refrigerant vapor up to superheated levels. In an embodiment, the compressor 110 discharges the superheated refrigerant vapor in addition to oil via a discharge line. The condenser 108 condenses the superheated refrigerant vapor to a subcooled refrigerant fluid. In certain embodiments, the condenser 108 additionally performs the function of separating oil from the oil-refrigerant vapor mixture received from the compressor 110. As used herein, “oil” refers to lubricating oil used to lubricate the moving components of the compressor 110. The oil in the compressor 110 also functions to cool bearings and to improve the tightness of the moving components to each other thereby increasing the efficiency.

FIG. 1C exemplarily illustrates a front perspective view of a heat sink 113, according to one or more embodiments of the disclosure. The heat sink 113 includes a supply conduit assembly 114 and a discharge conduit assembly 115. The supply conduit assembly 114 is adapted to receive a first portion of the subcooled refrigerant fluid from the condenser 108. The discharge conduit assembly 115 is adapted to discharge a superheated refrigerant vapor to the accumulator 109 such that the subcooled refrigerant fluid transitions to the superheated refrigerant vapor upon absorbing heat from a VFD unit (not shown) thermally coupled to the heat sink 113. The heat sink 113 may be connected to the condenser 108 and the accumulator 109 directly or indirectly. This means the heat sink 113 may be connected directly to the condenser 108 and the accumulator 109 without any intermediate components between them. Alternatively, when connected indirectly additional flow directing valves or flow regulating valves may be positioned between the heat sink 113 and the condenser 108 or the accumulator 109.

A remaining second portion of the subcooled refrigerant fluid is transferred to the expansion valve 111. The accumulator 109 is adapted to supply the superheated refrigerant vapor received from the heat sink 113 to the compressor 110. The expansion valve 111 expands the second portion of the subcooled refrigerant fluid. The evaporator 112 is adapted to receive the expanded second portion of the refrigerant fluid directly or indirectly. The evaporator 112 evaporates the expanded second portion of the refrigerant fluid. The compressor 110 compresses the evaporated refrigerant vapor from the evaporator 112 and the superheated refrigerant vapor received from the accumulator 109. The refrigerant circuit 100 further includes one or more valves for directing flow of the refrigerant fluid or the refrigerant vapor suitably. The valves may also be used to regulate the rate of refrigerant fluid or refrigerant vapor supply. In an embodiment, the air conditioning system further includes at least one valve for at least one of selectively preventing and selectively allowing flow of the first portion of the subcooled refrigerant fluid to the heat sink 113.

FIG. 2A exemplarily illustrates a front perspective view of the heat sink 113, according to one or more embodiments of the disclosure. FIG. 2B exemplarily illustrates a rear perspective view of the heat sink 113, according to one or more embodiments of the disclosure. FIG. 2C exemplarily illustrates a front planar view of the heat sink 113, according to one or more embodiments of the disclosure.

In one or more embodiments, the heat sink 113 includes a base 101 and a plurality of heat pipes 103. The plurality of heat pipes 103 are thermally coupled to the base 101 and extend from an outlet defined proximal to a high temperature region 101c of the base 101 towards an inlet defined proximal to a low temperature region 101d of the base 101. The heat sink 113 also includes the supply conduit assembly 114 and the discharge conduit assembly 115 as exemplarily illustrated in FIG. 1B. The supply conduit assembly 114 is adapted to be in fluid communication with a corresponding inlet of a heat pipe 103 from the plurality of heat pipes 103. The discharge conduit assembly 115 is adapted to be in fluid communication with a corresponding outlet of a heat pipe 103 from the plurality of heat pipes 103.

In one or more embodiments, the heat sink includes a plurality of heat passages 103′ exemplarily illustrated in FIG. 3B in place of the heat pipes 103 described earlier in the disclosure. A plurality of heat passages 103′ are defined in the base 101. Each of the plurality of heat passages 103′ extend from an outlet defined proximal to the high temperature region 101c of the base 101 towards an inlet defined proximal to the low temperature region 101d of the base 101. Each of the plurality of heat passages 103′ and the plurality of the heat pipes 103 include at least one evaporator section 103a proximal to the high temperature region 101c and at least one condenser section 103b proximal to the low temperature region 101d. The at least one condenser section 103b is in fluid communication with the at least one evaporator section 103a, such that the subcooled refrigerant fluid in the at least one condenser section 103b transitions to the superheated refrigerant vapor upon passing through the at least one evaporator section 103a. The supply conduit assembly 114 is in fluid communication with a corresponding inlet of a heat passage 103′ from the plurality of heat passages 103′. The discharge conduit assembly 115 is in fluid communication with a corresponding outlet of a heat passage 103′ from the plurality of heat passages 103′.

In one or more embodiments according to the disclosure, the heat sink 113, disclosed herein, includes the base 101 and the plurality of heat pipes 103. The base 101 includes a first face 101a, a second face 101b opposite to the first face 101a, and a plurality of fins 102 disposed on the second face 101b. In an embodiment, the fins 102 are of a cuboidal geometric configuration and positioned equidistant relative to each other. Moreover, the fins 102 extend outward from the high temperature region 101c of the base 101. In an embodiment, the fins 102 may extend in a transverse direction relative to the base 101. Furthermore, the fins 102 extend away from the base 101 for a distance ranging, for example, between 10 mm and 54 mm. The fins 102 towards the center of the low temperature region 101d of the base 101 are preferably longer than the fins 102 closer to the sides of the base 101. The plurality of heat pipes 103 are thermally coupled to the base 101 and extend from the high temperature region 101c towards the low temperature region 101d on the base 101. As used herein, the term “thermally coupled” may be construed to mean that the heat pipes 103 and the base 101 are engaged directly or indirectly such that a temperature change in the base 101 causes a corresponding temperature change in the heat pipes 103 or the heat passages 103′. This means the heat pipes 103 may be engaged directly with the base 101 without any intermediate components between them. Alternatively, when connected indirectly additional metallic layers, non-metallic layers, or coatings may be provided between the heat pipes 103 and the base 101. For the heat passages 103′, the coatings or additional metallic or non-metallic layers may be provided along an inner surface of the heat passages 103′. This is because the heat passages 103′ are defined as grooves within the base 101 and therefore form a portion of the base 101.

For example, if a heat source such as a printed circuit board or electronic components is mounted onto the base 101 and dissipates heat onto the base 101, the temperature of the base 101 rises. Accordingly, since the heat pipes 103 and the heat passages 103′ are engaged directly or indirectly to the base 101, the temperature of portions of the heat pipes 103 or the heat passages 103′ closer to the heat source increase. As such the region or regions surrounding the heat sources are accordingly termed as the “high temperature region 101c”. On the other hand, the temperature of portions of the heat pipes 103 or the heat passages 103′ away from the heat source is relatively lower, in the exemplary embodiment illustrated in FIG. 1A, and accordingly termed as the “low temperature region 101d”. This is because the fins 102 disposed on the second face 101b of the base 101 transfer heat to the ambient air thereby lowering the temperature of the portions of the heat pipes 103 or heat passages 103′ near the fins 102.

Each of the plurality of heat pipes 103 include the at least one evaporator section 103a proximal to the high temperature region 101c and the at least one condenser section 103b proximal to the low temperature region 101d. Moreover, the condenser section 103b is in fluid communication with the at least one evaporator section 103a. A refrigerant fluid flowing through the heat pipes 103 absorbs heat from the at least one evaporator section 103a to cool the high temperature region 101c. In an embodiment, the heat pipes 103, use refrigerant as the working fluid to rapidly transfer heat several times faster than a copper rod used alone. The heat pipes 103 function as energy-efficient thermal superconductors with no moving parts. As such, the heat pipes 103 transfer high rates of heat energy across extremely small and large temperature gradients.

As used herein, “refrigerant vapor” refers to refrigerant in a gaseous state. The refrigerant vapor may also include refrigerant in a liquid state entrained within the refrigerant vapor. However, a majority portion such as 80 percent and greater than 80 percent of the refrigerant particles are in the gaseous state and this collection of particles is referred to as the “refrigerant vapor”. Similarly, the term “refrigerant fluid” refers to refrigerant in the liquid state. The refrigerant fluid may also include refrigerant in the gaseous state in addition to the refrigerant liquid. However, a majority portion such as 80 percent and greater than 80 percent of the refrigerant particles are in the liquid state and this collection of particles is referred to as the “refrigerant fluid”.

In an embodiment, the heat pipes 103 may be made from metals having good thermal conductivity such as copper, nickel, titanium, aluminum, and stainless steel. In an embodiment, the heat pipes 103 may be of a rectangular cross-section and a circular cross-section. The material of the heat pipe 103 may be selected based on a type of refrigerant that is used. The refrigerant may include, but is not limited to, refrigerants such as R134A, R454B, R410A and the like. The operating range of a copper heat pipe 103, using the refrigerant, ranges, for example, between 25 to 150 degrees Celsius. The subcooled refrigerant fluid entering in the at least one condenser section 103b transitions to the superheated refrigerant vapor upon passing through the at least one evaporator section 103a.

Referring to FIG. 2A, a first diverter element 104 is adapted to connect at least one first header conduit 105 with a plurality of first branch conduits 105a for supplying the subcooled refrigerant fluid. In one or more embodiments, the supply conduit assembly 114, exemplarily illustrated in FIG. 1B, includes the first diverter element 104 adapted to connect the at least one first header conduit 105 with the plurality of first branch conduits 105a for supplying the subcooled refrigerant fluid. Each of the plurality of first branch conduits 105a is adapted to be in fluid communication with a corresponding inlet of a heat pipe 103 from the plurality of heat pipes 103. Alternatively, the plurality of first branch conduits 105a are in fluid communication with a corresponding inlet of a heat passage from the plurality of heat passages 103′. In one or more embodiments, the discharge conduit assembly 115, exemplarily illustrated in FIG. 1B, includes a second diverter element 106 adapted to connect at least one second header conduit 107 with a plurality of second branch conduits 107a for receiving the superheated refrigerant vapor. Each of the plurality of second branch conduits 107a is adapted to be in fluid communication with a corresponding outlet of a heat pipe 103 from the plurality of heat pipes 103 or a corresponding outlet of a heat passage 103′ from the plurality of heat passages 103′.

In an embodiment, the first diverter element 104 is adapted to receive the subcooled refrigerant fluid from the condenser 108. Similarly, the second diverter element 106 is adapted to supply the superheated refrigerant vapor to the accumulator 109. The subcooled refrigerant fluid in the first diverter element 104 transitions to the superheated refrigerant vapor in the second diverter element 106 upon absorbing heat from a Variable Frequency Drive (VFD) unit 202 as shown in FIGS. 3B, 4A-4C. In an embodiment, the VFD unit 202 is mounted on a portion of the base 101 corresponding to the at least one evaporator section 103a of the plurality of heat pipes 103.

FIG. 3A exemplarily illustrates a top view of an outdoor unit 200 showing the heat sink 113 according to one or more embodiments of the disclosure. The outdoor unit 200, disclosed herein, includes a housing 201 for the air conditioning system. The heat sink 113 is mounted along a portion of the housing 201, for example, as shown in FIG. 3A. In an embodiment, the housing 201 is of a hollow cuboidal geometrical configuration. The first face 101a of the base 101 and corner portions 201a of the housing 201 adjacent to the first face 101a of the base 101 collectively define a secondary internal space 204 enclosing the VFD unit 202 exemplarily illustrated in FIG. 3B. Similarly, the second face 101b and portions of the housing 201 excluding the corner portions 201a adjacent to the first face 101a of the base 101 define a primary internal space 205. The plurality of fins 102, extending from the second face 101b of the base 101 protrudes into the primary internal space 205 housing an axial fan 206. The axial fan 206 of the outdoor unit 200 pushes air across a large surface area of the heat sink 113 and the heat is dissipated into the discharged air.

In an embodiment, the heat sink 113 may be designed for medium base pans of the outdoor (OD) unit 200 and for mini base pans of the OD unit 200. In the heat sink 113 designed for medium base pans, the plurality of fins 102 cover the entire area of the second face 101b of the base 101. For mini base pans, the size of the OD unit 200 is also smaller. Since the size of the OD unit 200 is reduced, the blades of the axial fan 206 overlap with a region where a top portion of the plurality of fins 102 must be positioned. To overcome this drawback and to improve space utilization, the top portion of the plurality of fins 102 are cut down in the mini base pan. Therefore, for the mini base pan design, the plurality of fins 102 cover only the bottom portion of the second face 101b of the base 101 of the heat sink 113.

The subcooled refrigerant fluid enters the heat sink 113 through the first diverter element 104 and supplied through the first branch conduits 105a into the heat pipes 103 as exemplarily illustrated in FIG. 1A. The refrigerant fluid flows from the condenser section 103b and transitions to the superheated refrigerant vapor upon passing through the at least one evaporator section 103a. The subcooled refrigerant fluid in the first diverter element 104 transitions to the superheated refrigerant vapor in the second diverter element 106 upon absorbing heat from the VFD unit 202 mounted on the at least one evaporator section 103a of the plurality of heat pipes 103. The second diverter element 106 is adapted to connect the at least one second header conduit 107 with the plurality of second branch conduits 107a for receiving the superheated refrigerant vapor. Each of the second branch conduits 107a is adapted to be in fluid communication with a corresponding heat pipe 103 from the plurality of heat pipes 103.

FIG. 3B exemplarily illustrates a top view of the heat sink 113 with the variable frequency drive (VFD) unit 202 mounted on the heat sink 113 according to one or more embodiments of the disclosure. The heat sink 113 includes the base 101 having the first face 101a and the second face 101b. Referring to FIGS. 2A and 3B, the base 101 includes a plurality of fins 102 extending from the second face 101b of the base 101. Furthermore, the base 101 includes the heat pipes 103 thermally coupled to the base 101 and extending between the outlet proximal to the high temperature region 101c and the inlet proximal to the low temperature region 101d on the base 101 to improve cooling of the VFD unit 202. The VFD unit 202 is mounted on the first face 101a of the base 101 of the heat sink 113. In an embodiment, the VFD unit 202 is mounted on a portion of the base 101 corresponding to the at least one evaporator section 103a of the plurality of heat pipes 103. Alternatively, in implementations where heat passages 103′ are used, the VFD unit 202 is mounted on a portion of the base 101 corresponding to the at least one evaporator section 103a of the plurality of heat passages 103′. Moreover, the VFD unit 202 includes a plurality of control modules 203. Each control module 203 from among the plurality of control modules 203 is thermally coupled to at least one evaporator section 103a of a corresponding heat pipe 103 from among the plurality of heat pipes 103.

As used herein, the term “variable frequency drive (VFD) unit 202” may be construed to encompass one or a combination of microprocessors, insulated gate bipolar transistors (IGBT), suitable logic, circuits, printed circuit boards (PCB), audio interfaces, visual interfaces, haptic interfaces, or the like. In an exemplary implementation of the VFD unit 202 according to the disclosure, the VFD unit 202 includes the plurality of control modules 203. Each control module 203 includes the plurality of heat dissipating electronic components such as insulated gate bipolar transistors (IGBTs) and the like. The VFD unit 202 may include, but are not limited to a microcontroller, a Reduced Instruction Set Computing (RISC) processor, an Application-Specific Integrated Circuit (ASIC) processor, a Complex Instruction Set Computing (CISC) processor, a central processing unit (CPU), a graphics processing unit (GPU), a state machine, and/or other processing units 201-1 or circuits. The VFD unit 202 may also comprise suitable logic, circuits, interfaces, and/or code that may be configured to execute a set of instructions stored in a memory unit. In an exemplary implementation of the memory unit according to the disclosure, the memory unit may include, but are not limited to, Electrically Erasable Programmable Read-only Memory (EEPROM), Random Access Memory (RAM), Read Only Memory (ROM), Hard Disk Drive (HDD), Flash memory, Solid-State Drive (SSD), and/or CPU cache memory. Moreover, the VFD unit 202 may receive power from a suitably coupled power source. For example, a battery or power source may be electrically coupled to supply electrical power to the VFD unit 202. In an embodiment, the power source may be, for example, a battery, such as a rechargeable battery or a non-rechargeable battery. Examples of suitable batteries include, for example, a lithium battery (such as a lithium-ion battery), a nickel battery (such as a nickel-cadmium battery), and an alkaline battery.

The variable frequency drive (VFD) unit 202 may be installed as a part of a building management system and transmit and/or receive data from a centralized computing device. As such, the VFD unit 202 may also include a communications unit configured to transmits data to and receives data from the computing device via a communications network. The communications unit may be configured of, for example, a telematic transceiver (DCM), a mayday battery, a GPS, a data communication module ASSY, a telephone microphone ASSY, and a telephone antenna ASSY. In an embodiment, the computing device may be implemented as a portion of a small-form factor portable (or mobile) electronic device such as a cell phone, a personal data assistant (PDA), a personal media player device, a wireless web-watch device, a personal headset device, an application specific device, or a hybrid device that include any of the above functions. The centralized computing device may also be implemented as a personal computer including both laptop computer and non-laptop computer configurations. The computing device can also be any type of network computing device.

The computing device can also be an automated system as described herein. The computing device may have additional features or functionality, and additional interfaces to facilitate communications between basic configuration and any devices and interfaces. For example, a bus/interface controller may be used to facilitate communications between a basic configuration and one or more data storage devices via a storage interface bus. The Data storage devices may be removable storage devices, non-removable storage devices, or a combination thereof. Examples of the removable storage and the non-removable storage devices include magnetic disk devices such as flexible disk drives and hard-disk drives (HDD), optical disk drives such as compact disk (CD) drives or digital versatile disk (DVD) drives, solid state drives (SSD), and tape drives to name a few. Further, computer storage media may include, For example, volatile and non-volatile, removable, and non-removable media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules, or other data systems can also be used for data analysis.

FIG. 4A exemplarily illustrates a perspective view of an embodiment of the heat sink 113 with I-shaped heat pipes 103 according to one or more embodiments of the disclosure. The subcooled refrigerant fluid enters the heat sink 113 through the first diverter element 104 and supplied into the condenser section 103b and transitions to the superheated refrigerant vapor upon passing through the at least one evaporator section 103a. The subcooled refrigerant fluid in the first diverter element 104 transitions to the superheated refrigerant vapor in the second diverter element 106 upon absorbing heat from the VFD unit 202 mounted on the at least one evaporator section 103a of the plurality of heat pipes 103. The second diverter element 106 is adapted to receive the superheated refrigerant vapor.

Each of the heat pipes 103 include at least one evaporator section 103a proximal to the high temperature region 101c and at least one condenser section 103b proximal to the low temperature region 101d as exemplarily illustrated in FIGS. 2A-2C. The condenser section 103b is in fluid communication with the at least one evaporator section 103a, such that the refrigerant transfers heat from the at least one evaporator section 103a to the condenser section 103b. The refrigerant may include, but is not limited to, a refrigerant, ammonia, water, and the like. The refrigerant is transferred from the at least one condenser section 103b to the at least one evaporator section 103a by a capillary action of the plurality of heat pipes 103. In an embodiment, a diameter of the heat pipes 103 used may range, for example, between 4 mm and 8 mm. A larger diameter heat pipe 103 can transport more vapor, translating into a larger heat carrying capacity. The maximum heat load carrying capacity of the heat pipe 103 depends on several parameters, for example, a total length of the heat pipe 103, a length of the evaporator section 103a, a length of the condenser section 103b, a diameter of the heat pipe 103, an orientation of the heat pipe 103, a shape of the heat pipe 103, and number of passages of the heat pipe 103.

In an embodiment, the variable frequency drive (VFD) unit 202 is mounted on the first face 101a of the base 101 of the heat sink 113. The VFD unit 202 includes a plurality of control modules 203. Each control module 203 includes a plurality of heat dissipating electronic components such as insulated gate bipolar transistors (IGBTs) and the like. A control module 203 from among the plurality of control modules 203 is thermally coupled to a portion of the base 101 corresponding to the at least one evaporator section 103a of a corresponding heat pipe 103 from among the plurality of heat pipes 103. The at least one evaporator section 103a and the at least one condenser section 103b are disposed vertically along a longitudinal axis Y-Y′ of the base 101 to form an I-shaped heat pipe 103.

FIG. 4B exemplarily illustrates a perspective view of another embodiment of the heat sink 113 with C-shaped heat pipes 103, according to one or more embodiments of the disclosure. In the embodiment, the at least one evaporator section 103a and the at least one condenser section 103b are disposed horizontally along a lateral axis X-X′ of the base 101 and separated by a connecting section 103c to collectively form a C-shaped heat pipe 103.

FIG. 4C exemplarily illustrates a perspective view of yet another embodiment of the heat sink 113 with S-shaped heat pipes 103. In the embodiment, the at least one evaporator section 103a and the at least one condenser section 103b are disposed horizontally along the lateral axis X-X′ of the base 101 and separated by the connecting section 103c. The connecting section 103c includes at least one sub section such that the at least one evaporator section 103a, the at least one condenser section 103b, and the connecting section 103c including the sub sections collectively form the S-shaped heat pipe 103. It must be appreciated that the number of sub sections may be increased to improve heat transfer. Moreover, the shape of the heat pipes 103 may be suitably modified to improve the heat transfer.

The heat sink 113 disclosed herein rapidly transfer heat through the heat pipes 103 several thousand times faster than a conventional copper rod in the absence of a refrigerant. The heat pipes 103 are energy-efficient thermal superconductors with no moving parts, transferring high rates of heat energy across extremely small and large temperature gradients. As such, the absence of moving parts reduces the potential for wear and tear. Furthermore, the absence of moving parts ensures absence of noise as in the case of conventional cooling mechanisms utilizing rotating or moving components.

Advantageously, the refrigerant circuit 100 using the heat sink 113, disclosed herein, includes minor adjustments to existing variable frequency drive (VFD) mounting platforms for implementation. The subcooled refrigerant fluid enters the heat sink 113 through the first diverter element 104 and supplied through the first branch conduits 105a into the heat pipes 103 as exemplarily illustrated in FIG. 1A. The refrigerant fluid flows from the condenser section 103b and transitions to the superheated refrigerant vapor upon passing through the at least one evaporator section 103a. The subcooled refrigerant fluid in the first diverter element 104 transitions to the superheated refrigerant vapor in the second diverter element 106 upon absorbing heat from the VFD unit 202 mounted on the at least one evaporator section 103a of the plurality of heat pipes 103. The second diverter element 106 is adapted to connect the at least one second header conduit 107 with the plurality of second branch conduits 107a for receiving the superheated refrigerant vapor. Each of the second branch conduits 107a is adapted to be in fluid communication with a corresponding heat pipe 103 from the plurality of heat pipes 103.

Since no complex modifications or design elements may be envisioned for diverting refrigerant through the heat sink 113, the cost of implementation also reduces. Further, the inclusion of only minor adjustments ensures optimal use of the available space restricted due to the dimensions of the outdoor unit components, for example, the axial fan 206 as exemplarily illustrated in FIG. 2A. Moreover, reusing the refrigerant already used in the air conditioning system eliminates implementation of additional cooling mechanisms. Advantageously, since the refrigerant circuit 100 through the heat sink 113 recirculates the first portion of the refrigerant within the heat sink 113, the heat management of the electronic components of the VFD unit 202 mounted on the heat sink 113 is optimized while ensuring lower power consumption.

Advantageously, referring to FIGS. 3A-3C, the provision of the evaporator section 103a along the high temperature region 101c of the base 101 from which the fins 102 extend outward ensures improved heat transfer. The refrigerant fluid works as an active heat transfer component whereas the fins 102 function as a passive heat transfer component. The refrigerant fluid serves to optimally transfer the heat away from the region of heat generation. As such, the heat is more evenly distributed over the entire surface of the base 101 thereby preventing the formation of localized hotspots. This feature reduces the possibility of damage to the electronic components of the variable frequency drive (VFD) unit 202 during extreme ambient temperatures.

While specific language has been used to describe the subject matter, any limitations arising on account thereto, are not intended. As would be apparent to a person in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein. The drawings and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of processes described herein may be changed and are not limited to the manner described herein. Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all the acts necessarily need to be performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts.

Benefits, other advantages, and solutions to problems have been described above regarding specific embodiments. However, the benefits, advantages, solutions to problems, and any component(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, or essential feature or component of any or all the claims.

Claims

1. A refrigerant circuit for cooling a Variable Frequency Drive (VFD) unit of an air conditioning system, the refrigerant circuit comprising: a condenser for condensing refrigerant vapor;a heat sink comprising a supply conduit assembly and a discharge conduit assembly, wherein the supply conduit assembly is adapted to receive a first portion of a subcooled refrigerant fluid from the condenser and the discharge conduit assembly is adapted to discharge a superheated refrigerant vapor to an accumulator, wherein the subcooled refrigerant fluid transitions to the superheated refrigerant vapor upon absorbing heat from the VFD unit thermally coupled to the heat sink;the accumulator adapted to supply the superheated refrigerant vapor to a compressor;an expansion valve for expanding a second portion of the condensed refrigerant fluid;an evaporator for evaporating the expanded second portion of the refrigerant fluid; andthe compressor, for compressing the evaporated refrigerant vapor from the evaporator and the superheated refrigerant vapor received from the accumulator.

2. The refrigerant circuit of claim 1, further comprising at least one valve for at least one of selectively preventing and selectively allowing flow of the first portion of the subcooled refrigerant fluid to the heat sink.

3. The refrigerant circuit of claim 1, wherein the heat sink comprises: a base;a plurality of heat passages defined in the base, each of the plurality of heat passages extending from an outlet defined proximal to a high temperature region of the base towards an inlet defined proximal to a low temperature region of the base, each of the plurality of heat passages comprising: at least one evaporator section proximal to the high temperature region; andat least one condenser section proximal to the low temperature region and in fluid communication with the at least one evaporator section, wherein the subcooled refrigerant fluid in the at least one condenser section transitions to the superheated refrigerant vapor upon passing through the at least one evaporator section;the supply conduit assembly adapted to be in fluid communication with a corresponding inlet of a heat passage from the plurality of heat passages; andthe discharge conduit assembly adapted to be in fluid communication with a corresponding outlet of a heat passage from the plurality of heat passages.

4. The refrigerant circuit of claim 1, wherein the heat sink comprises: a base comprising: a first face;a second face opposite to the first face; anda plurality of fins disposed on the second face and extending from a high temperature region of the base;a plurality of heat pipes thermally coupled to the base and extending from an outlet defined proximal to the high temperature region of the base towards an inlet defined proximal to a low temperature region of the base, each of the plurality of heat pipes comprising: at least one evaporator section proximal to the high temperature region; andat least one condenser section proximal to the low temperature region and in fluid communication with the at least one evaporator section, wherein a subcooled refrigerant fluid in the at least one condenser section transitions to a superheated refrigerant vapor upon passing through the at least one evaporator section;the supply conduit assembly adapted to be in fluid communication with a corresponding inlet of a heat pipe from the plurality of heat pipes; andthe discharge conduit assembly adapted to be in fluid communication with a corresponding outlet of a heat pipe from the plurality of heat pipes.

5. The refrigerant circuit of claim 1, wherein the supply conduit assembly comprises: a first diverter element adapted to connect at least one first header conduit with a plurality of first branch conduits for supplying the subcooled refrigerant fluid, each of the plurality of first branch conduits adapted to be in fluid communication with at least one of a corresponding inlet of a heat pipe from the plurality of heat pipes and a corresponding inlet of a heat passage from the plurality of heat passages.

6. The refrigerant circuit of claim 1, wherein the discharge conduit assembly comprises: a second diverter element adapted to connect at least one second header conduit with a plurality of second branch conduits for receiving the superheated refrigerant vapor, each of the plurality of second branch conduits adapted to be in fluid communication with at least one of a corresponding outlet of a heat pipe from the plurality of heat pipes and a corresponding outlet of a heat passage from the plurality of heat passages.

7. The refrigerant circuit of claim 1, wherein the VFD unit is mounted on a first face of a base of the heat sink, the VFD unit comprising: a plurality of control modules, wherein one control module from the plurality of control modules is thermally coupled to at least one evaporator section of a corresponding heat passage from the plurality of heat passages and the at least one evaporator section of a corresponding heat pipe from the plurality of heat pipes.

8. The refrigerant circuit of claim 5, wherein the first diverter element is adapted to receive the subcooled refrigerant fluid from the condenser.

9. The refrigerant circuit of claim 6, wherein the second diverter element is adapted to supply the superheated refrigerant vapor to an accumulator.

10. The refrigerant circuit of claim 7, wherein the subcooled refrigerant fluid in a first diverter element transitions to the superheated refrigerant vapor in a second diverter element upon absorbing heat from the VFD unit mounted on a portion of the base corresponding to at least one of the at least one evaporator section of the plurality of heat pipes and the at least one evaporator section of the plurality of heat passages.

11. The refrigerant circuit of claim 3, wherein the at least one evaporator section and the at least one condenser section are disposed vertically along a longitudinal axis Y-Y′ of the base to form at least one of an I-shaped heat pipe and an I-shaped heat passage.

12. The refrigerant circuit of claim 3, wherein the at least one evaporator section is disposed vertically along a longitudinal axis Y-Y′ of the base and the at least one condenser section is disposed horizontally along a lateral axis X-X′ of the base to collectively form at least one of an L-shaped heat pipe and an L-shaped heat passage.

13. The refrigerant circuit of claim 3, wherein the at least one evaporator section and the at least one condenser section are disposed horizontally along a lateral axis X-X′ of the base and separated by a connecting section to collectively form at least one of a C-shaped heat pipe and a C-shaped heat passage.

14. The refrigerant circuit of claim 13, wherein the connecting section comprises at least one sub section.

15. A refrigerant circuit for cooling a Variable Frequency Drive (VFD) unit of an outdoor unit of an air conditioning system, the refrigerant circuit comprising: a condenser for condensing refrigerant vapor;a heat sink for receiving a first portion of a subcooled refrigerant fluid from the condenser, the heat sink comprising: a supply conduit assembly and a discharge conduit assembly, wherein the supply conduit assembly is adapted to receive the first portion of the subcooled refrigerant fluid from the condenser and the discharge conduit assembly is adapted to discharge a superheated refrigerant vapor to an accumulator, wherein the first portion of the subcooled refrigerant fluid transitions to the superheated refrigerant vapor upon absorbing heat from the VFD unit thermally coupled to the heat sink;the accumulator adapted to supply the superheated refrigerant vapor to a compressor;an expansion valve for expanding a second portion of the subcooled refrigerant fluid;an evaporator for evaporating the expanded second portion of the subcooled refrigerant fluid; anda compressor, for compressing the evaporated refrigerant vapor from the evaporator and the superheated refrigerant vapor received from the accumulator.

16. The refrigerant circuit of claim 15, wherein the outdoor unit comprises: a housing;a heat sink according to claims 3 or 4 mounted along a portion of the housing, the heat sink comprising: a first diverter element adapted to connect at least one first header conduit with a plurality of first branch conduits for supplying the subcooled refrigerant fluid, each of the plurality of first branch conduits adapted to be in fluid communication with at least one of a corresponding inlet of a heat pipe from the plurality of heat pipes and a corresponding inlet of a heat passage from the plurality of heat passages; anda second diverter element adapted to connect at least one second header conduit with a plurality of second branch conduits for receiving the superheated refrigerant vapor, each of the plurality of second branch conduits adapted to be in fluid communication with at least one of a corresponding outlet of a heat pipe from the plurality of heat pipes and a corresponding outlet of a heat passage from the plurality of heat passages; andthe VFD unit mounted on the first face of the base of the heat sink, the VFD unit comprising: a plurality of control modules, wherein at least one control module from the plurality of control modules is thermally coupled to at least one of the at least one evaporator section of a corresponding heat pipe from the plurality of heat pipes and the at least one evaporator section of a corresponding heat passage from the plurality of heat passages.

17. The refrigerant circuit of claim 15, wherein a first face of the base and corner portions of the housing adjacent to the first face of the base collectively define a secondary internal space enclosing the VFD unit.

18. The refrigerant circuit of claim 15, wherein a second face and portions of the housing excluding the corner portions adjacent to the first face of the base define a primary internal space.

19. The refrigerant circuit of claim 15, wherein a plurality of fins disposed on the second face and extending from a high temperature region of the base protrudes into the primary internal space housing an axial fan.

20. The refrigerant circuit of claim 15, wherein the subcooled refrigerant fluid in the first diverter element transitions to the superheated refrigerant vapor in the second diverter element upon absorbing heat from the VFD unit mounted on at least one of the at least one evaporator section of a corresponding heat pipe from the plurality of heat pipes and the at least one evaporator section of a corresponding heat passage from the plurality of heat passages.