Patent Application
20210302082
This invention relates generally to ergonomically designed heating and cooling equipment and, in particular, to distributed controller arrangements for chillers used for heating, ventilation, air conditioning and refrigeration.
This section is intended to introduce the reader to various aspects of the art that may be related to various aspects of the presently described embodiments—to help facilitate a better understanding of various aspects of the present embodiments. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Modern residential and industrial customers expect indoor spaces to be climate controlled. In general, heating, ventilation, and air-conditioning (“HVAC”) systems circulate an indoor space's air over low-temperature (for cooling) or high-temperature (for heating) sources, thereby adjusting the indoor space's ambient air temperature. HVAC systems generate these low- and high-temperature sources by, among other techniques, taking advantage of a well-known physical principle: a fluid transitioning from gas to liquid releases heat, while a fluid transitioning from liquid to gas absorbs heat.
In a typical residential system, a fluid refrigerant circulates through a closed loop of tubing that uses compressors and other flow-control devices to manipulate the refrigerant's flow and pressure, causing the refrigerant to cycle between the liquid and gas phases. These phase transitions generally occur within the HVAC's heat exchangers, which are part of the closed loop and designed to transfer heat between the circulating refrigerant and flowing ambient air. This is the foundation of the refrigeration cycle. The heat exchanger where the refrigerant transitions from a gas to a liquid is called the “condenser,” and the condensing fluid releases heat to the surrounding environment. The heat exchanger where the refrigerant transitions from liquid to gas is called the “evaporator,” and the evaporating refrigerant absorbs heat from the surrounding environment.
For commercial or industrial applications, chillers are an economical way to control the indoor climate of large buildings. Within a typical chiller system, multiple fluid loops cooperate to transfer heat from one location to another. At the core of a typical chiller is the refrigerant loop that circulates a fluid refrigerant transitioning between liquid and gaseous phases, to create the desired absorption or release of heat. This is similar to traditional residential systems. But instead of the refrigerant transferring or absorbing heat directly to or from the surrounding or circulating air, chillers often employ loops of circulating water to which or from which heat is transferred. To cool the building, the refrigerant loop's evaporator may be designed to absorb heat from water circulating in a chilled-water loop that, in turn, absorbs heat from the indoor environment via a heat exchanger in an air-handling unit. And the refrigerant loop's condenser may be designed to release heat from the circulating refrigerant to water circulating in a cooling-water loop that, in turn, releases heat to the outdoor environment via a heat exchanger in a cooling tower.
Chiller size can vary depending on the tonnage of the chiller. A Refrigeration Ton (RT) is equal to the amount of heat required to melt one ton of ice in a 24-hour period or about equal to 12,000 BTU/hour. Commercial or industrial chillers may be at least 30 RTs and can be as high as 2,000 tons or higher.
In some chillers, the location of control boxes and panels can present an issue. In some chillers, control boxes are placed above the average operator height which requires the operator to use a ladder or stairs to access the control box. Alternatively, a control box may be placed next to the chiller which increases the total footprint of the chiller. In applications where the control box is placed in a generally accessible location, the use of a single large control box may also present issues for the operator.
Certain aspects of some embodiments disclosed herein are set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of certain forms the invention might take and that these aspects are not intended to limit the scope of the invention. Indeed, the invention may encompass a variety of aspects that may not be set forth below.
Embodiments of the present disclosure generally relate to a chiller system for supplying chilled water to a building comprising a chiller that has a capacity of at least 30 tons, a first chiller control box that has an upper surface that is less than two meters high, and a second chiller control box that has an upper surface that is less than two meters high and is in data communication with the first chiller control box.
Embodiments of the present disclosure generally relate to a refrigeration system comprising a chiller with at least a 300 refrigeration ton (RT) capacity mounted on a frame, one of more programmable logic controllers, a first control box mounted on the frame, and a second control box mounted on the frame. The first control box is in wireless communication with the second control box, and the first and second control boxes each have an upper side and a lower side. The lower side of the first control box and second control box is about 1.6 meters high and the upper side of the first control box and second control box is about 1.8 meters high.
In some embodiments, one or more chiller control boxes is ergonomically positioned so that an operator can access the control box without the use of a ladder and without reaching overhead. The ergonomic positioning of one or more control boxes reduces the likelihood of operator injury due to falling or shoulder strain.
Various refinements of the features noted above may exist in relation to various aspects of the present embodiments. Further features may also be incorporated in these various aspects as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to one or more of the illustrated embodiments may be incorporated into any of the above-described aspects of the present disclosure alone or in any combination. Again, the brief summary presented above is intended only to familiarize the reader with certain aspects and contexts of some embodiments without limitation to the claimed subject matter.
These and other features, aspects, and advantages of certain embodiments 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:
One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
Turning to the figures,
The now-liquid refrigerant leaving the condenser 125 in the refrigerant loop transitions into a low-pressure liquid when it passes through an expansion valve 127. This drop in pressure also reduces the temperature of the refrigerant as it becomes a low-pressure liquid. The cool low-pressure liquid then enters the evaporator 145 where heat is transferred back into the refrigerant, converting the refrigerant into back into a low-pressure gas to be compressed by the compressor. The heat transferred to the refrigerant in the evaporator 145 is provided by water circulating in a chilled-water loop 150, often through a heat exchanger in the evaporator 145. The chilled-water loop 150 carries the now-cooled water to air-handling units (AHUs) 160 that circulate the building's indoor air over a heat exchanger, to cool the indoor space. It is envisaged that the refrigerant could be any number of refrigerants, including, without limitation, R410A, R32, R454B, R452B, R134a, R513A, R515A, R515B, HFO refrigerants such as HFO-1234ze, HFO-1233zd, or HFO-1234yf, or any number of combinations thereof.
A control box allows an operator or use to operate, adjust, manage, diagnose, maintain, and/or repair the chiller. A control box may contain terminal blocks, programmable logic controller (PLC) inputs and outputs, human machine interface (HMI), relays, power supplies, circuit breakers or fuses, PC modules, noise filter and/or a power conditioning circuit. These components are generally contained within a housing or cabinet. Traditionally, these components have been housed within a single large control box housing. This arrangement centralizes the components, but can require that an operator reach a significant distance from the bottom of the control box to the top of the control box while operating the device. For some operators, this may mean that at least a portion of the control box is outside of the ideal working height for that user even if the user is on a ladder.
In some instances, the operator may be forced to either work overhead or bend down to access the control box or certain controls within the control box. Working overhead or working while bending down both violate general safety principles and can lead to accidents and injuries even without the use of a ladder.
In some embodiments, at least two of the plurality of control boxes are in communication with each other. In some embodiments, a chiller includes a single primary control box and plurality of secondary control boxes. In such embodiments, one or all of the secondary control boxes are in communication with the primary control box. In some embodiments, the user may operate the chiller from the primary control box without physically accessing the secondary control boxes.
In some embodiments, the control boxes may be separated based on function. For example, a first control box may provide the operator with data and control feature related to temperature, a second control box may provide the operator with data and control features related to pressure, and a third control box may provide the operator with data and control features related to powering the chiller system. In some embodiments, this arrangement simplifies wiring arrangements and may reduce wiring errors. In some embodiments, the use of multiple separate control boxes reduces the amount of electrical noise at certain locations in the chiller and/or control box.
In some embodiments, two or more control boxes are in wired communication with each other and/or a sensor, processor, controller, or other chiller component that is positioned outside of the control boxes. Chiller sensors may include but are not limited to, for example, temperature sensors, pressure sensors, flow sensors, voltage sensors, amperage sensors, RPM sensors, and/or liquid sensors.
In some embodiments, the chiller is configured to transmit data from one or more sensors to the plurality of control boxes. One or more of the plurality of control boxes is configured to display the data to an operator and/or allow the operator to control the operations of the chiller through a human machine interface (HMI).
In some embodiments, two or more control boxes are in wireless communication with each other. In some embodiments, one or more control box is in wireless communication with a sensor, processor, controller, or other chiller component that is positioned outside of the control box. Wireless communication may be achieved using a Wi-Fi, Bluetooth®, radio-wave, infrared, or similar methods of data communication. In some embodiments, a local wireless communication module is used to transmit wireless signals from a first control box to a second control box. In some embodiments, multiple modalities of wireless communication may be used within a single chiller system.
In some embodiments, an indicator light or other notification provides the operator with an indication of the communication status between multiple control boxes or between a control box and a sensor. If electrical noise or any other external factor interferes with the transmission of a data signal from a sensor to a control box or from a first control box to a second control box, the indicator light informs the operator. The operator may use the information from this indicator light to determine if service is required or if the operations of the chiller should be adjusted. In some embodiments, if certain data signals are interrupted, the chiller may deactivate or transition to a safe state until the operator can diagnose or remedy the cause of the interrupted data signal.
As can be seen by comparing
In some embodiments, a high tonnage chiller (at least 30 refrigeration tons) is equipped with two or more control boxes. The first control box is in data communication with the second control box and with a chiller sensor positioned outside of the control boxes. The first and second control boxes each have an upper surface that is less than two meters above the surface that the chiller rests on and the operator stands on when accessing the control boxes. The first and second control boxes each have a lower surface that is higher than 1.5 meters above the surface that the chiller rests on and the operator stands on when accessing the control boxes.
While the aspects of the present disclosure may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. But it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
