Modular two phase loop distributed HVACandR system

An HVAC&R system that includes a first pumping device configured to circulate a first volume of a first two-phase medium, a second pumping device configured to circulate a second volume of the first two-phase medium, a first plurality of secondary HVAC&R units, a second plurality of secondary HVAC&R units, a first primary HVAC&R unit, and a second primary HVAC&R unit. At least one of the first plurality of secondary HVAC&R units is operably coupled to the first pumping device. At least one of the second plurality of secondary HVAC&R units is operably coupled to the second pumping device. The first primary HVAC&R unit is operably coupled to at least one of the first plurality of secondary HVAC&R units and the first pumping device. The second primary HVAC&R unit is operably coupled to at least one of the second plurality of secondary HVAC&R units and the second pumping device.

TECHNICAL FIELD OF THE DISCLOSED EMBODIMENTS

The presently disclosed embodiments generally relate to heating, ventilation, air conditioning and refrigeration (“HVAC&R”) systems, and more particularly, to a two phase loop distributed HVAC&R system.

BACKGROUND OF THE DISCLOSED EMBODIMENTS

Typically, buildings contain HVAC&R systems that include either roof top units or chillers for cooling operation, and direct gas-fired units or boilers for heating operation. In some instances, there is a requirement to simultaneously heat and cool different areas of the building. Typically, conventional HVAC systems incur energy waste by reheating cooled air to maintain comfort for the areas that require heating operation. Typically, these systems use a single phase heat transfer loop, operate at a single temperature lift, and are inefficient at transferring heat between different areas of the building.

Accordingly, there exists a need for a system that can efficiently heat and cool a building simultaneously.

SUMMARY OF THE DISCLOSED EMBODIMENTS

In accordance with an embodiment of the present disclosure, an HVAC&R system is provided. The system includes a first pumping device configured to circulate a first volume of a first two-phase medium, a second pumping device configured to circulate a second volume of the first two-phase medium, a first plurality of secondary HVAC&R units, wherein at least one of the first plurality of secondary HVAC&R units is operably coupled to the first pumping device, a second plurality of secondary HVAC&R units, wherein at least one of the second plurality of secondary HVAC&R units is operably coupled to the second pumping device, a first primary HVAC&R unit operably coupled to at least one of the first plurality of secondary HVAC&R units and the first pumping device, and a second primary HVAC&R unit operably coupled to at least one of the second plurality of secondary HVAC&R units and the second pumping device. The first pumping device, a portion of each of the first plurality of secondary HVAC&R units, and a portion of the first primary HVAC&R unit form a first primary loop, and the second pumping device, a portion of each of the second plurality of secondary HVAC&R units, and a portion of the second primary HVAC&R unit form a second primary loop.

Each of the first plurality of secondary HVAC&R units and the second plurality of secondary HVAC&R units may include a secondary compressor configured to circulate a second two-phase medium, a first secondary heat exchanger operably coupled to the secondary compressor, a secondary expansion device operably coupled to the first secondary heat exchanger, and a second secondary heat exchanger operably coupled to the secondary expansion device and the secondary compressor. A portion of each of the first primary loop and the second primary loop may be operably coupled to one or more first secondary heat exchangers. At least one of the plurality of secondary HVAC&R units may be a non-vapor, compression-based heat pumping device thermally coupled to the first two-phase medium. Each of the first primary HVAC&R unit and the second primary HVAC&R unit may include a primary compressor configured to circulate a third two-phase medium, a first primary heat exchanger operably coupled to the primary compressor, a primary expansion device operably coupled to the first primary heat exchanger, and a second primary heat exchanger operably coupled to the primary expansion device and the primary compressor. A portion of each of the first primary loop and the second primary loop may be operably coupled to the first primary heat exchanger. The first two-phase medium may include carbon dioxide. The second two-phase medium may include a refrigerant. The third two-phase medium may include a refrigerant. Each of the first plurality of secondary HVAC&R units and the second plurality of secondary HVAC&R units may include a heat pump. Each of the first primary HVAC&R unit and the second primary HVAC&R unit may include a heat pump. The system may further include an airflow device disposed on each of the first primary loop and the second primary loop, the airflow device may be configured to direct airflow onto each of the first primary loop and the second primary loop. The system may further include at least one conduit operably coupled to at least one of the first plurality of secondary HVAC&R units and the second plurality of secondary HVAC&R units, and an airflow device operably coupled to the at least one conduit, wherein the airflow device may be configured to circulate outdoor air to the at least one of the first plurality of secondary HVAC&R units and the second plurality of secondary HVAC&R units. The first pumping device may be configured to operate at a first pumping capacity, the second pumping device may be configured to operate at a second pumping capacity, the first plurality of secondary HVAC&R units may be configured to operate at a first secondary capacity, the second plurality of secondary HVAC&R units may be configured to operate at a second secondary capacity, the first primary HVAC&R unit may be configured to operate at a first primary capacity, and the second primary HVAC&R unit may be configured to operate at a second primary capacity. The system may further include a controller configured to vary at least one of the first pumping capacity, the second pumping capacity, the first secondary capacity, the second secondary capacity, the first primary capacity, and the second primary capacity. The controller may be further configured to vary at least one of the first pumping capacity, the second pumping capacity, the first secondary capacity, the second secondary capacity, the first primary capacity, and the second primary capacity by providing a subcooled or saturated first medium entering at least one of the first pumping device and the second pumping device. A first portion of the first plurality of secondary HVAC&R units may be disposed within a first interior space. A second portion of the first plurality of secondary HVAC&R units may be disposed within a second interior space. A first portion of the second plurality of secondary HVAC&R units may be disposed within a third interior space. A second portion of the second plurality of secondary HVAC&R units may be disposed within a fourth interior space.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS

FIG. 1schematically illustrates an embodiment of an HVAC&R system, generally indicated at10, configured to condition air within a plurality of interior spaces12A-B within a structure13. The HVAC&R system10includes a pumping device14configured to circulate a first medium21; a valve16, for example a four-way valve, operably coupled to the pumping device14, the valve16configured to direct the flow of the first medium21. The HVAC&R system10further includes; a primary HVAC&R unit20operably coupled to the valve16. The HVAC&R system10further includes a plurality of secondary heat pumping HVAC&R units18A-B operably coupled to the primary HVAC&R unit20and the pumping device14. The pumping device14, valve16, plurality of secondary HVAC&R units18A-B and primary HVAC&R unit20are in flow communication with one another to form a primary loop22. In an embodiment, the plurality of secondary HVAC&R units18A-B and the primary HVAC&R unit20are heat pumps.

The pumping device14is configured to circulate the first medium21through the primary loop22, and valve16is configured to direct the flow of the first medium21in the primary loop22. In an embodiment, the first medium21includes a first two-phase fluid. In an embodiment, the first two-phase fluid includes liquid carbon dioxide. For example, the first two-phase fluid may be at least 50 percent by weight of carbon dioxide. It will be appreciated that the first two-phase fluid may include a percentage weight less than 50 percent. In one embodiment, the first two-phase fluid may be any refrigerant. It will be appreciated that the pumping device14is further configured to maintain the first medium21in a two-phase state in the secondary loop to minimize heat losses.

The plurality of secondary HVAC&R units18A-B are configured to condition the air within the plurality of interior spaces12A-B. It will be appreciated that each of the plurality of secondary HVAC&R units18A-B is capable of providing at least part of the capacity needed in each of the plurality of interior spaces12A-B at a reduced temperature lift of the second medium33A-B as it flows between the first secondary heat exchanger28A-B and the second secondary heat exchanger26A-B (as shown inFIG. 2), respectively. Energy rejected or absorbed by any of the plurality of secondary HVAC&R units18A-B may be accessed by downstream secondary HVAC&R units18with zero temperature change in the first medium21due to heat exchange. It will further be appreciated that the plurality of secondary HVAC&R units18may be arranged in series or parallel. It will further be appreciated that the secondary HVAC&R unit may be any type of heat pumping device, including without limitation vapor-compression, solid state, or natural gas-based. For a solid state heat pump, it may include any solid state technology, such as, without limitation, electrocaloric, thermoelectric, magnetocaloric, thermoionic, thermoacoustic, or thermoelastic. The primary HVAC&R unit20is configured to heat or cool the first medium21, as later described herein.

The HVAC&R system10further includes a controller23in electrical communication with the pumping device14, the valve16, each of the plurality of secondary HVAC&R units18A-B, and the primary HVAC&R unit20. The controller23is configured to control the operation of the primary HVAC&R unit20, and the pumping device14to process, circulate and direct the flow of the first medium21. In an embodiment, the controller23is further configured to control the operation of the valve16to direct the flow of the first medium21.

In an embodiment, the controller23is configured to vary the capacity of at least one of the pumping device14and the primary HVAC&R unit20to conserve energy and reduce the temperature lift required to meet the required demand. In some embodiments, the capacity of the pumping device14and the primary HVAC&R unit20may be varied to ensure that the first medium21enters the pumping device14as subcooled or saturated liquid. Based on pressure and temperature of the first medium21measured at the inlet of the pumping device14, the controller23may adjust the speed of pumping device14in the primary loop22and the speed/stage of primary compressor34(shown inFIGS. 3-5, 7-11).

In a cooling dominant mode, if the measured temperature of the first medium21is lower than a saturation temperature at a measured pressure by less than a given threshold, e.g., approximately 0.5° C., the controller23may decrease the speed of the pumping device14and increase the speed/stage of the primary compressor34if needed. If the measured temperature of the first medium21is lower than the saturation temperature at the measured pressure by more than a given threshold, e.g., approximately 5.0° C., the controller23may decrease the speed/stage of primary compressor34and increase the speed of pumping device14if needed.

In heating dominant mode, if the measured temperature of the first medium21is lower than a saturation temperature at a measured pressure by less than a given threshold, e.g., approximately 0.5° C., the controller23may decrease the speed/stage of primary compressor34and decrease the speed of the pumping device14if needed. If the measured temperature of the first medium21is lower than the saturation temperature at the measured pressure by more than a given threshold, e.g., approximately 5.0° C., the controller23may increase the speed of the pumping device14and increase the speed/stage of primary compressor34, if needed. In some embodiments, a first storage device15including a first storage volume17may be used before the pumping device14for this purpose.

FIG. 2provides another view of the HVAC&R system10. In the embodiment shown, each of the plurality of secondary HVAC&R units18A-B includes a secondary compressor24, a second secondary heat exchanger26, a first secondary heat exchanger28, and a secondary expansion device30in flow communication with one another to form an independent secondary HVAC&R loop32within each secondary HVAC&R unit18A-B in which a second medium33is circulated therethrough. In an embodiment, the second medium33includes a second two-phase fluid. In an embodiment, the second two-phase fluid includes a refrigerant. It will be appreciated that the second medium33may be the same medium or a different medium within the plurality of secondary HVAC&R units18.

The primary HVAC&R unit20includes a primary compressor34, a first primary heat exchanger36, a second primary heat exchanger38, and a primary expansion device40in flow communication with one another to form an independent third HVAC&R loop42in which a third medium43is circulated therethrough. In an embodiment, the third medium43includes a third two-phase fluid. In an embodiment, the third two-phase fluid includes a refrigerant.

The HVAC&R system10is configured such that the primary loop22passes through the first secondary heat exchanger28of each of the plurality of secondary HVAC&R units18A-B and through the first primary heat exchanger36.

For an illustration of operation of the HVAC&R system10, assume interior space12B has a cooling demand greater than a heating demand for interior space12A. It will be appreciated that the system10will determine the overall demand of the structure13as a function of a heating demand, cooling demand, or a combination of the demand of the plurality of interior spaces12A-B. When the cooling demand is greater, controller23transmits a signal to the primary HVAC&R unit20to operate in a cooling mode. As such, the primary compressor34begins to pump high-pressure, high-temperature third medium43vapor into the second primary heat exchanger38. The third medium43is cooled into high-pressure, high-temperature liquid and goes through the primary expansion device40where it becomes low-pressure, low-temperature two phase fluid. Thereafter, the low-pressure, low-temperature two phase fluid enters the first primary heat exchanger36. Simultaneously, pumping device14circulates the first medium21through valve16. The first medium21is directed through the first primary heat exchanger36and as the first medium21flows through the first primary heat exchanger36heat is exchanged from first medium21to the low-pressure, low-temperature two phase third medium43.

The absorption of heat in the third medium43flowing through first primary heat exchanger36causes the third medium43to return to a low-pressure, low-temperature vapor state. The low-pressure, low-temperature vapor enters the primary compressor34where it turns into a high-pressure, high-temperature vapor. Thereafter, the high-pressure, high-temperature vapor enters the second primary heat exchanger38where the third medium43releases heat to external fluid, for example, ambient air, and condenses into a high-pressure, high-temperature liquid. The high-temperature liquid travels back through the expansion device40where it becomes low-pressure, low-temperature two phase fluid and returns to the primary heat exchanger36.

To condition spaces12A (heating) and12B (cooling), the now cooled first medium21liquid is directed to the secondary HVAC&R unit18B. Secondary HVAC&R unit18B operates in a cooling mode due to the cooling demand in interior space12B. As such secondary compressor24B pumps high-pressure, high-temperature second medium33B vapor through the first secondary heat exchanger28B. The first medium21and the second medium33B simultaneously flow through the first secondary heat exchanger28B, and as a result, the second medium33B vapor releases heat into the first medium21causing the first medium21to contain more vapor and causes the second medium33B to return to a high-pressure, high-temperature liquid state.

The now high-pressure, high-temperature second medium33B liquid enters the secondary expansion device30B where it turns into a low-pressure, low-temperature two phase fluid. Thereafter, the low-pressure, low-temperature two phase fluid enters the second secondary heat exchanger26B where fan46B blows air across the second secondary heat exchanger26B to send cool air into interior space12B.

The two phase first medium21continues to flow to the secondary HVAC&R unit18A. The secondary HVAC&R unit18A is operating in a heating mode to condition the interior space12A. Here, the secondary compressor24A pumps high-pressure, high temperature second medium33A vapor through a reversing valve (not shown), and the high-pressure, high-temperature refrigerant vapor flows through the second secondary heat exchanger26A. The second medium33A releases heat in the air as fan46A blows air across the second secondary heat exchanger26A to send warm air into interior space12A. The second medium33A turns into a high-pressure, high-temperature liquid when it enters secondary expansion device30A where it changes state to a low-pressure, low-temperature two phase fluid and enters the first secondary heat exchanger28A.

The first medium21and the second medium33A simultaneously flow through the first secondary heat exchanger28A, and as a result the low-pressure, low-temperature two-phase second medium33A absorbs heat from the two phase first medium21to change the second medium33A to a low-pressure, low-temperature vapor before it reenters the secondary compressor24A. As a result, the temperature lift of the second medium33A is effectively reduced; thus, increasing the efficiency of the HVAC&R system10and providing heat to space18A.

As the heat from the first medium21is absorbed into the second medium33A, the first medium21returns to a liquid state where it reenters the first primary heat exchanger36to begin the cycle again. It will be appreciated that the flow of the first medium21, the second medium33A-B, and the third medium43may be reversed depending on the mode of operation (i.e., heating or cooling).

For example, the flow of the first medium21, the second medium33A-B, and the third medium43in an all heating mode is shown inFIG. 3. The first medium21flows from the pumping device14, through the valve16, through the first primary heat exchanger36, through the first secondary heat exchangers28A and28B of the respective secondary HVAC&R units18A-B, back to the pumping device14. The second medium33A-B flows from the secondary compressor24A-B through the second secondary heat exchanger26A-B, through the secondary expansion device30, and through the first secondary heat exchanger28A-B before returning to the secondary compressor24. The third medium43flows from the primary compressor34to the first primary heat exchanger36, through the primary expansion device40, and through the second primary heat exchanger38before returning to the primary compressor34. It will be appreciated that any of the secondary HVAC&R units18A-B may be off.

For example, the flow of the first medium21, the second medium33A-B, and the third medium43in an all cooling mode is shown inFIG. 4. The first medium21flows from the pumping device14, through the first secondary heat exchangers28A-B of the respective secondary HVAC&R units18A-B, through the first primary heat exchanger36, and through the valve16before returning to the pumping device14. The second medium33A-B flows from the secondary compressor24A-B through the first secondary heat exchanger28A-B, through the secondary expansion device30, and through the second secondary heat exchanger26A-B, before returning to the secondary compressor24. The third medium43flows from the primary compressor34to the second primary heat exchanger38, through the primary expansion device40, and through the first primary heat exchanger36before returning to the primary compressor34. It will be appreciated that any of the secondary HVAC&R units18A-B may be off.

In some embodiments, a sensing device48(as shown inFIGS. 2-11) is disposed on the primary loop22. The sensing device48is configured to monitor the fluid state of the first medium to ensure the first medium does not become significantly subcooled or superheated, and to maintain some subcooling at the inlet of the pumping device14to prevent cavitation by varying the primary HVAC unit20and the pumping device14through the controller23.

As shown in the embodiment ofFIG. 5, an airflow device50, for example an economizer, is disposed adjacent to the primary loop22. The airflow device50is configured to direct outdoor air onto the primary loop22to effectively cool the first medium21as it flows therethrough. For example, when the outdoor air temperature is at or below a given temperature effective to cool the first medium21, the pumping device14may circulate the first medium21through the primary loop22in a cooling mode configuration. As the first medium21passes the airflow device50the first medium21is partly or fully condensed before it enters the primary HVAC&R unit20and the plurality of secondary HVAC&R units18A-B. The condensed first medium21absorbs heat from the flowing second medium within the plurality of secondary HVAC&R units18A-B.

As shown in the embodiment ofFIG. 6, an airflow device52is in airflow communication with at least one of the plurality of secondary HVAC&R units18A-B. The airflow device52is configured to deliver outdoor air to at least one of the plurality of secondary HVAC&R units18A-B. For example, outdoor air is delivered to at least one of the plurality of secondary HVAC&R units18A-B via a conduit54. The outdoor air enters at least one of the plurality of secondary HVAC&R units18A-B via a damper56A or56B where it is mixed with return air58A or58B from the interior space12A or12B, respectively. The now mixed air is pulled across the second secondary heat exchanger26A or26B via the fan46A or46B (as shown inFIGS. 2-4) to deliver conditioned air to the interior space12A or12B. When a space is in cooling mode, device52is controlled to increase the flow rate of outdoor air when the outdoor air condition is appropriate to reduce or eliminate the mechanical cooling load on the secondary HVAC&R units18A-B.

In one embodiment, as shown inFIG. 7, a portion of the secondary HVAC&R units18A-B may be disposed within the interior space12A-B, respectively. In an embodiment, the secondary compressor24, the second secondary heat exchanger26, and the secondary expansion device30are disposed within the interior space12A-B. In another embodiment, as shown inFIG. 8a first portion of the secondary HVAC&R units18A-B may be disposed within the interior space12A-B, respectively, and a second portion of the secondary HVAC&R units18A-B may be disposed within a secondary interior space60. In an embodiment, the secondary interior space60is an unoccupied space.

Placing a portion(s) of the secondary HVAC&R units18A-B within the interior space12A-B, respectively and/or secondary interior space60is operable to mitigate the risks associated with the amount of the first medium21that may enter the occupied interior space12A-B. For example, if there is a leak in the primary loop22, the first medium21may be properly contained in a mechanically ventilated restricted area (secondary interior space60) or naturally vented outside (as shown inFIG. 7).

In an embodiment, as shown inFIG. 9, a second valve62is operably coupled to the primary loop22between the pumping device14and one of the secondary HVAC&R units18A-B. A pressure container64is operably coupled to the second valve62.

Using the second valve62and pressure container64is operable to maintain positive pressure within the primary loop22in cold ambient temperature conditions, and maintain the design pressure in hot ambient temperature conditions by preventing non-condensable gases from leaking into the two-phase loop during extremely cold weather, and avoiding release during extremely hot weather. In other embodiments, the HVAC&R system10is operable to maintain positive pressure within the primary loop22in cold ambient temperature conditions, and maintain the design pressure in hot ambient temperature conditions by directing exhaust air over the storage device15to pre-heat or pre-cool the primary loop22. It is also operable to maintain positive pressure within the primary loop22in cold ambient temperature conditions by operating the pump device14.

In an embodiment, as shown inFIG. 10, the system10further includes a second storage device70containing a second storage volume72. In an embodiment, the second storage volume includes a two-phase fluid. The second storage device70is disposed within the primary loop22between valve16and one of the secondary HVAC&R units18A-B. The second storage device70is operably coupled valve16via a vapor conduit74located in a position above the second storage volume72, and a liquid conduit76located in a position such that the second storage volume72may flow therethrough. In an embodiment, the diameter of the vapor conduit74is larger than the diameter of the liquid conduit.

By separating the vapor and the liquid of the two-phase fluid retuning to the primary HVAC unit20, the second storage device70, vapor conduit74, and liquid conduit76operate to effectively reduce an overall charge of the two-phase fluid within the system10. The overall system charge of the system10is reduced based on the vapor and liquid traveling at the same pressure drop within the vapor conduit74and liquid conduit76, respectively. Because the liquid phase has a higher density than the vapor, the liquid conduit76may be smaller in size (i.e. diameter); thus, reducing the flow area.

In an embodiment, as shown inFIG. 11, a second pumping device78is operably coupled to the primary loop22between the second storage device70and one of the secondary HVAC&R units18A-B. In the embodiment shown, the fluid conduit76is operably coupled to an inlet of the second pumping device76. In an embodiment, the controller23is operably coupled to the second pumping device23for the control thereof. The outlet of the second pumping device30is operably coupled to the primary loop22before one of the secondary HVAC&R units18A-B. This configuration also effectively reduces the overall charge of the system10and improves the energy efficiency by circulating the second storage volume72back in to the supply for the secondary HVAC&R units18A-B.

Referring now toFIG. 12, a modular HVAC&R system300in accordance with an embodiment of the present disclosure is illustrated. A first HVAC&R system100is configured to condition air within a plurality of interior spaces112A-B and a second HVAC&R system200is configured to condition air within a plurality of interior spaces212A-B. In additional embodiments not illustrated, the first system100and/or the second system200includes only one interior space112,212or more than two interior spaces112,212. Further, in additional embodiments not illustrated, the first system100and the second system200are joined by additional systems to form the modular HVAC&R system300described herein.

A first primary HVAC&R unit120is operably coupled to one or more of the first plurality of secondary HVAC&R units118A-B and the first pumping device114. A second primary HVAC&R unit220is operably coupled to one or more of the second plurality of secondary HVAC&R units218A-B and the second pumping device214. The first pumping device114, a portion of each of the first plurality of secondary HVAC&R units118A-B, and a portion of the first primary HVAC&R unit120form a first primary loop122. The second pumping device214, a portion of each of the second plurality of secondary HVAC&R units218A-B, and a portion of the second primary HVAC&R unit220form a second primary loop222.

Each system100,200may include the same components and features described with regard to HVAC&R system10in one or more embodiments. A first pumping device114is configured to circulate a first volume of a first two-phase medium in the first system100, while a second pumping device214is configured to circulate a second volume of the first two-phase medium. The first system100includes a first plurality of secondary HVAC&R units118A-B, and one or more of the first plurality of secondary HVAC&R units118A-B is operably coupled to the first pumping device114. The second system200includes a second plurality of secondary HVAC&R units218A-B, and one or more of the second plurality of secondary HVAC&R units218A-B is operably coupled to the second pumping device214.

The first pumping device114is configured to operate at a first pumping capacity, the second pumping device214is configured to operate as second pumping capacity, the first plurality of secondary HVAC&R units118A-B is configured to operate at a first secondary capacity, the second plurality of secondary HVAC&R units218A-B is configured to operate at a second secondary capacity, the first primary HVAC&R unit120is configured to operate at a first primary capacity, and the second primary HVAC&R unit220is configured to operate at a second primary capacity. The modular system illustrated inFIG. 12includes at least one controller (not shown) configured to vary at least one of the first pumping capacity, the second pumping capacity, the first secondary capacity, the second secondary capacity, the first primary capacity, and the second primary capacity. The controller may vary one or more of the first pumping capacity, the second pumping capacity, the first secondary capacity, the second secondary capacity, the first primary capacity, and the second primary capacity by providing a subcooled or saturated first medium entering the first pumping device114and/or the second pumping device214.

As with the system10described above, in one or more embodiments, one or more of the first plurality of secondary HVAC&R units118A-B and the second plurality of secondary HVAC&R units218A-B includes a secondary compressor124A-B,224A-B configured to circulate a second two-phase medium, a first secondary heat exchanger128A-B,228A-B operably coupled to the secondary compressor124A-B,224A-B, a secondary expansion device130A-B,230A-B operably coupled to the first secondary heat exchanger128A-B,228A-B, and a second secondary heat exchanger126A-B,226A-B operably coupled to the secondary expansion device130A-B,230A-B and the secondary compressor124A-B,224A-B. A portion of each of the first primary loop122and the second primary loop222is operably coupled to one or more of the first secondary heat exchangers128A-B,228A-B.

Further, one or more embodiments of the present disclosure not illustrated include one or both of the first primary HVAC&R unit120and the second primary HVAC&R unit220having a primary compressor configured to circulate a third two-phase medium, a first primary heat exchanger136operably coupled to the primary compressor, a primary expansion device operably coupled to the first primary heat exchanger136, and a second primary heat exchanger236operably coupled to the primary expansion device and the primary compressor. A portion of each of the first primary loop122and the second primary loop222is operably coupled to one or more first secondary heat exchangers128A-B,228A-B.

As with system10described above, the HVAC&R systems100,200may include one or more airflow devices disposed on each of the first primary loop122and the second primary loop222whereby the airflow device(s) directs airflow onto each of the first primary loop122and the second primary loop222. Similarly, at least one conduit is operably coupled to one or both of the first plurality of secondary HVAC&R units118A-B and the second plurality of secondary HVAC&R units218A-B. The airflow device(s) may be operably coupled to the conduit(s). The airflow device(s) is configured to circulate outdoor air to one or more of the first plurality of secondary HVAC&R units118A-B and the second plurality of secondary HVAC&R units218A-B.

As illustrated inFIG. 12, a first portion of the first plurality of secondary HVAC&R units118A is disposed within a first interior space112A. A second portion of the first plurality of secondary HVAC&R units118B is disposed within a second interior space112B. A first portion of the second plurality of secondary HVAC&R units218A is disposed within a third interior space212A. A second portion of the second plurality of secondary HVAC&R units218B is disposed within a fourth interior space212B. It will be appreciated that the modular system300, including each of the HVAC&R systems100,200, is operably connected to the building structure13such that each module or system100,200may operate independently from another. Such operation decreases individual two-phase loop system charge. Reduction of charge allows the system300to meet maximum charge requirements set by ASHRAE Standards 15 and 34. Further, the module operation increases reliability of the overall system, minimizes installation cost, and reduces energy consumption at partial loads. In one non-limiting example, when extreme conditions are present in one of the interior spaces112A-B,212A-B, the modular operation reduces energy and increases reliability by only requiring elevated operation, such as through the controller increasing flow rate and/or capacity, for a system operably connected to the interior space experiencing the extreme conditions.

Any “pump” or “pumping” term included in the present disclosure, including the pumping device14, first pumping device114, and/or second pumping device214, refers to a fluid pumping device in one or more embodiments, and refers to a liquid and/or gas pumping device in one or more additional embodiments of the present disclosure. Further, any heat pump or heat pumping device described or identified herein may include a non-vapor, compression-based heat pumping device or another solid state heat pumping device in one or more embodiments, as well as a conventional heat pump device in one or more embodiments.

It will therefore be appreciated that the present embodiments include HVAC&R systems10,110,210,300including a two-phase fluid flowing through a primary loop22,122,222to interconnect a primary HVAC&R unit20,120,220with independently controlled secondary HVAC&R units18A-B,118A-B,218A-B to more efficiently heat and cool interior spaces12A-B,112A-B,212A-B by effectively reducing the temperature lift of the second medium within the plurality of secondary HVAC&R units18A-B,118A-B,218A-B.

While the disclosure has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain embodiments have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.