Patent Application
20170146268
The present subject matter relates generally to water chiller apparatuses and appliances.
Water chilling units have been adopted for wide range of commercial and residential settings. Whether the need is for a precisely-chilled medical imaging device, or an immediately-accessible supply of cooled drinking water, water chillers have numerous potential uses. However, most existing water chillers are only available for large-scale operations. The high costs and/or large footprint of these existing machines makes them unusable for many potential customers. Although some conventional systems may offer a large supply of pre-chilled water, many potential users have neither the space nor resources needed to invest in these conventional systems. Other conventional systems may require less space, but typically have little, if any, storage capacity for pre-chilled water.
In addition, the energy requirements for some such systems can be quite high. When the need for chilled water arises, users may be forced to wait a considerable amount of time for water to reach the appropriate temperature. If the stored amount of chilled water is minimal, the user will risk quickly exhausting the chiller's supply. Even when rapid chilling is possible, conventional systems typically require a user to expend large amounts of electrical power to quickly chill lukewarm water. The delay and/or expense of using such systems makes these conventional systems impractical for many potential uses and/or users.
As a result, there is a need for an efficient and inexpensive water chiller that requires less space than conventional systems, while still providing an adequate amount of immediately-accessible pre-chilled water storage.
The present disclosure relates, generally, to a chiller apparatus including a storage tank and a refrigerant cooling system. The refrigerant cooling system includes a compressor, condenser, and evaporator attached to the storage tank to efficiently cool liquid therein. Advantageously, the chiller apparatus may be smaller and less expensive to operate than conventional systems. Additional aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.
In one exemplary embodiment, a chiller apparatus for cooling a liquid is provided. The chiller apparatus includes a storage tank for storing the liquid and a refrigerant cooling system. The storage tank has a top, a bottom, and an outer surface. The refrigerant cooling system includes a compressor attached to the storage tank, a condenser positioned downstream from the compressor to condense a refrigerant received therefrom, and at least one evaporator positioned downstream of the condenser and wrapped about the outer surface of the storage tank. The evaporator includes a negative pitch coil configured to direct refrigerant flow from a position near the top of the storage tank to a position near the bottom of the storage tank.
In another embodiment a chiller apparatus is provided. The chiller apparatus includes a storage tank defining an interior volume for the receipt of liquid to be chilled. The storage tank includes a sidewall having an inner surface defining the interior volume and configured for contact with the liquid. The storage tank has an outer surface not contacting the liquid, and a bottom portion and a top portion. The chiller apparatus includes a support plate disposed over the storage tank, and a sealed cooling system for circulating a refrigerant. The cooling system includes a compressor mounted to the support plate for compressing the refrigerant, a condenser positioned downstream from the compressor on the support plate to condense the refrigerant received from the compressor, and at least one evaporator positioned downstream of the condenser and wrapped about the outer surface of the sidewall. The evaporator includes a negative pitch coil configured to direct a refrigerant flow from the top portion of the storage tank toward the bottom portion of the storage tank.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
Turning to the figures,
As shown in
The tank 112, itself, includes a sidewall 120 having an inner surface 122 defining the interior volume 114 and configured for contact with the water to be chilled. An outer surface 124 of the sidewall 120 is defined opposite the inner surface 122 and does not contact the chilled liquid. The top or top portion 116 of the tank 112 and the bottom or bottom portion 118 of the tank 112 abut the sidewall 120 and enclose the interior volume 114.
The water chiller apparatus 100 includes a sealed refrigerant cooling system 126 for cooling water stored or supplied to the tank 112. Generally, the sealed refrigerant cooling system 126 is configured to circulate a refrigerant through or near the tank 112 to draw heat therefrom. Included in the sealed cooling system 126 are a compressor 128, a condenser 130, a throttling device 132, and an evaporator 134. As is generally understood, various conduits may be utilized to flow or direct refrigerant between the various components of the sealed system 126. The compressor 128, condenser 130, throttling device 132, and evaporator 134 may each be placed in fluid communication such that refrigerant generally flows downstream from the compressor 128 to the rest of the system before returning to the compressor 128.
During operation, the compressor 128 motivates the refrigerant through the sealed cooling system 126 and acts to compress the refrigerant through the compressor 128, itself, increasing pressure and temperature of the refrigerant such that the refrigerant becomes a superheated vapor. As a superheated vapor, the refrigerant then passes to the condenser 130, which may be positioned directly downstream from the compressor 128. Within the condenser 130, the refrigerant is cooled as heat is drawn therefrom. The refrigerant subsequently exits the condenser 130 as a saturated liquid and/or high quality liquid vapor mixture. A fluid filter 136 may be provided downstream of the condenser 130 to draw excessive moisture from the saturated liquid and/or high quality liquid vapor mixture. This high quality/saturated liquid vapor mixture then travels through the throttling device 132, which is configured for regulating a flow rate of refrigerant therethrough. The throttling device 132 may generally expand the refrigerant, lowering the refrigerant's pressure and temperature. As a result, a cooled form of the refrigerant passes to the evaporator 134. While passing through the evaporator 134, the cooled refrigerant absorbs heat transferred to the storage tank 112 from the water therein. Refrigerant ideally exits the evaporator 134 in a gasified vapor form before passing back to the compressor 128. An accumulator 138 is provided in some embodiments and may be configured to maintain gasification of the fluid flow as the refrigerant passes from the evaporator 134 to the compressor 128. Upon the refrigerant reaching the compressor 128, the cycle repeats.
One or more tank temperature sensors 140 may be included and configured for measuring a temperature of water within the interior volume 114 of the storage tank 112. The tank temperature sensor 140 may be positioned at any suitable location within or on the storage tank 112. For example, the tank temperature sensor 140 may be positioned within the interior volume 114 of the storage tank 112 or disposed on the tank sidewall 120. The tank temperature sensor 140 may, moreover, be configured in operable communication with the compressor 128 to indicate when the compressor 128 should be activated to circulate refrigerant. Such embodiments may provide indicate when additional or decreased cooling is needed. In some embodiments, multiple tank temperature sensors 140 may be included to provide temperature measurements at multiple positions of the tank 112.
A controller 142 may be included and configured to control or regulate the water chiller apparatus 100 and/or sealed cooling system 126. Controller 142 may be, for example, in operable communication with the sealed system 126 (such as the compressor 128, and/or other components thereof), and/or temperature sensor 140. Thus, controller 142 can selectively activate system 126 in order to cool water within the interior volume 114 of the storage tank 112.
Controller 142 includes memory and one or more processing devices such as microprocessors, CPUs or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of the water chiller apparatus 100. The memory can represent random access memory such as DRAM, or read only memory such as ROM or FLASH. The processor executes programming instructions stored in the memory. The memory can be a separate component from the processor or can be included onboard within the processor. Alternatively, controller 142 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.
As illustrated in
In optional or additional embodiments, the condenser 130 may be mounted to the support plate 144 above the tank 112. The condenser 130 may, moreover, include one or more air handler 160. The air handler 160 may be positioned within casing on or adjacent a condenser body 162. Thus, when activated, the air handler 160 may direct a flow of air towards or across the condenser 130, and assist with drawing heat from the refrigerant within the condenser body 162. The air handler 160 may be any suitable type of air handler, such as an axial or centrifugal fan. The condenser body 162 may be any suitable conduit structure for directing the refrigerant therethrough. One or more heat exchange fins may extend therefrom and assist with heat transfer between the air and refrigerant.
Throttling device 132 may be disposed above the tank 112 adjacent to the condenser 130. The throttling device 132, itself, may be any suitable components for generally expanding the refrigerant. For example, in some exemplary embodiments, throttling device 132 may be a Joule-Thomson expansion valve, also known as a “J-T valve.” In other exemplary embodiments, throttling device 132 may be an ejector. In still other exemplary embodiments, a capillary tube, fixed orifice, or other suitable apparatus may be utilized as throttling device 132. In certain exemplary embodiments, throttling device 132 may be an electronic expansion valve (EEV).
As shown, the evaporator 134 may include a negative pitch coil 166 positioned generally downstream of the condenser 130 and/or directly downstream of the throttling device 132. As illustrated, the coil 166 of some embodiments is wrapped about the outer surface 124 of the sidewall 120, in direct contact thereto. In one exemplary embodiment, the coil 166 is affixed to the storage tank 112 using a thermal paste that improves heat transfer. In another embodiment, the coil 166 is welded to the tank 112. As shown in the exemplary embodiment in
In certain embodiments, the coil 166 has a negative pitch angle θ defined relative to the top 116 of the tank 112. As result, the negative pitch coil 166 may have an entry port 168 disposed vertically higher than an exit port 170 when the tank 112 is vertically positioned. In an additional or alternative embodiment, the negative pitch coil 166 has a negative pitch angle θ relative to the support plate 144 of the water chiller apparatus 100. In such embodiments, the support plate 144 of the water chiller apparatus 100 may define a horizontal plane which the negative pitch coil 166 extends away from. The negative pitch coil 166 may, advantageously, aid heat flow within the storage tank 112. Specifically, the negative pitch coil 166 is configured to conduct heat at a higher rate near a top portion 116 of the tank 112 than at a bottom portion 118 of the tank 112. The disparate heat transfers may thereby generate a fluid flow of water within the storage tank 112. Chilled water from the top portion 116 of the interior volume 114 can flow downward toward the bottom portion 118 of the interior volume 114 as relatively warm water flows upwards from the bottom portion 118.
As shown in
In certain embodiments of the apparatus 100, it is desirable to increase the surface area for contact between the negative pitch coil 166 and the storage tank 112. Such an increase will provide increased heat transfer between the coil 166 and the tank 112 for a given length of the coil 166. Moreover, it can decrease the overall length of coil required to transfer heat from the tank 112 (and water therein) to the coil 166. In additional or alternative embodiments, it may be desirable to increase the surface area and shape of the tank inner surface 122 in contact with water within the interior volume 114. The increased surface area and changes in shape advantageously improve the contact area with the water and alter the film coefficient of convective heat transfer from the tank inner surface 122 to the water.
Accordingly, the storage tank 112 of some embodiments includes one or more groove 178 formed along the outer surface 124 of the cylindrically-shaped sidewall 120 along an axial direction A, as shown in
As further shown in
The groove 178 in some embodiments has a depth De in radial direction R that is less than the outer diameter Di of the coil 166. In such embodiments, the coil 166 extends beyond the outer surface 124 of cylindrically-shaped sidewall 120 of the storage tank 112. Alternatively, the groove 178 may have a depth De that is greater than the outer coil diameter Di of the coil 166. The groove 178 may also have a width along the axial direction, A, approximately equal to the outer diameter Di of the coil 166. It is envisioned that other configurations may be used as well.
In another exemplary embodiment, the storage tank 112 could be formed out of a process such that the interior surface of the tank 112 has a plurality of internal heat transfer features—e.g., ribs, fins, or the like—that project into the tank 112 and extend longitudinally along the axial direction A of the tank 112. For example,
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
