BALANCE

CROSS-REFERENCE TO RELATED APPLICATIONS

[001] The present application claims priority to United States Provisional Patent Application No. 62/490,461, filed on April 26, 2017 (pending), the entirety of which is incorporated herein by reference for all purposes and made a part of the present disclosure.

FIELD

[002] The present disclosure relates generally to methods, systems, and apparatus for balancing thermal energy needs within a local environment. More particularly, the present disclosure relates to a high efficiency, refrigerant based thermal management system for independently controlling the direction and rate of refrigerant flow for multiple service devices within a controlled region.

BACKGROUND

[003] According to a 2016 U.S. Energy Information Administration (EIA) study, IEO2016, worldwide energy consumption has nearly doubled in the last 30 years from 350 to nearly 600 quadrillion British Thermal Units (BTUs), with fossil fuel sources accounting for nearly 80% of the worldwide energy consumption. With worldwide energy consumption expenditures estimated to total nearly 6 trillion U.S. dollars (USD), or 10% of the world gross domestic product (GDP), and associated social and environmental concerns, effective energy management is becoming an ever-increasing priority.

[004] In response to these concerns, two technologies have gained significant focus in an attempt to improve efficiencies, reduce waste, balance loads and minimize environmental impact, including: (1) distributed power; and (2) waste heat management. Distributed power is generally realized as a decentralized network of local micro-energy producers, such as natural gas powered combined heating and power (CHP) systems and combined cooling, heating and power (CCHP) systems, as well as renewable sources, such as wind and solar power. Waste heat management generally takes the form of enhanced system design and resource management including regenerators, economizers, waste heat recovery (WHR) technologies, and smarter, more flexible control systems.

[005] With developing technologies, energy systems are complicated by numerous standards, competing systems, and design constraints, including feasibility and flexibility in being both adaptable for future revisions and compatible with older existing designs and infrastructure. These problems have materialized in the development of grid-tied systems, which can operate either independently or become grid dependent upon needs and resources to handle electrical power demands. The development of more advanced variable flow refrigeration and direct expansion systems is becoming more commonplace, replacing older and less efficient air duct architectures to handle heating and cooling needs. This involves a complex array of existing air duct systems, vapor compression refrigeration systems, heat pumps, direct expansion cooling, and 2 and 3 pipe variable flow refrigerant systems. To date, no single technology has been able to bridge all such systems effectively.

SUMMARY

[006] In one aspect, the present disclosure is directed to high efficiency thermal management systems and methods for balancing thermal energy needs within a local environment. Such systems include a variable flow refrigerant (VFR) system composed of a variable speed compressor, external heat sink or condenser, external heat source or evaporator, and a series of multiple internal heat exchangers within the local environment that are connected via a 2-pipe refrigerant system. The 2-pipe refrigerant system includes a series of dedicated liquid phase lines and a manifold system, allowing for connection to either high or low-pressure gas reservoirs. The 2-pipe refrigerant system also includes fluid-to-fluid heat exchangers, allowing system coupling with other refrigerant-based heat systems.

[007] In one aspect, the system disclosed herein is simple, adaptable, flexible, and scalable, such that the system is capable of accommodating and integrating with a majority of varied heating, cooling and general HVAC systems. For example, the 2-pipe variable flow refrigerant architecture may include modularized components, and fluid and thermal interfaces configured to accommodate operational coupling with various service devices having different standards, materials, mediums (e.g., working fluids), control systems, loads, and applications.

[008] In some embodiments of the methods and systems disclosed herein, an outside unit is used that contains a variable speed electrical or mechanical driven compressor with multi-port manifolds (high- and low-pressure manifolds) at both the compressor inlet and outlet. Such an outside unit accommodates connection to both an internal refrigerant cycle and an array of inside, application exchangers via the 2-pipe system. In addition to the multi-port compressor manifolds, the internal refrigerant cycle of the outside unit also includes a dedicated condenser and evaporator for exchanging thermal energy with the outside environment, and a liquid manifold in fluid communication with the application exchangers. The system of inside, application exchangers is composed of an array of application exchangers located within a controlled environment. Each individual application exchanger is connected using two pipes (i. e., the 2-pipe system). A first pipe connects between a particular application exchanger, directly to the liquid manifold within the outside unit. A second pipe connects between the particular application exchanger to a common port of a 3 -way electronic expansion valve (e.g. , solenoid valve), which is integrated within the outside unit. The 3-way electronic expansion valve bridges (i. e. , provides fluid communication between) the high- and low-pressure manifolds of the outside unit compressor, allowing either manifold (high- or low-pressure) to be directly connected to the inside, application exchanger. Using an array of such 3-way electronic expansion valves and pipes, embodiments of the system disclosed herein are capable of providing any combination of heating and heat recovery functionalities, simultaneously, including coupling with other fluidically independent refrigeration-based systems using fluid- to -fluid heat exchangers.

[009] In certain aspects, the present disclosure provides for a thermal management system. The thermal management system includes a refrigerant system positioned outside of a local environment. The refrigerant system includes a compressor, a heat sink, and a heat source. The compressor, heat sink, and heat source are fluidly coupled in a refrigerant cycle loop. At least one service device is positioned within the local environment. The thermal management system includes a 2-pipe bus that includes liquid and gas phase lines. The liquid and gas phase lines fluidly couple at least one heat exchanger positioned within the local environment with the refrigerant system. The at least one heat exchanger is thermally coupled with the at least one service device. Each service device is independently connected in parallel with the heat source and the heat sink via the 2-pipe bus.

[0010] In some aspects, the present disclosure provides for a method of transferring heat between service devices. The method includes thermally coupling a plurality of service devices positioned within a local environment with a refrigerant system positioned outside of the local environment. The refrigerant system includes a compressor, heat sink, and heat source. The compressor, heat sink, and heat source are fluidly coupled in a refrigerant cycle loop. The service devices are thermally coupled with the refrigerant system via a 2-pipe bus. The 2-pipe bus includes liquid and gas phase lines. The liquid and gas phase lines fluidly couple at least one heat exchanger positioned within the local environment with the refrigerant system. Each heat exchanger is thermally coupled with one of the service devices. Each service device is independently connected in parallel with the heat source and the heat sink via the 2-pipe bus. [0011] Certain aspects of the present disclosure relate to methods, systems and apparatus for transferring thermal energy out of, into, and/or between multiple service devices using the 2- pipe bus and refrigerant system disclosed herein. For example, thermal energy may be transferred from one service device into the working fluid of the refrigerant system, and into another of the service devices from the working fluid via the 2-pipe bus. In some aspects, thermal energy may be transferred from one service device into the working fluid of the refrigerant system to preheat the working fluid, followed by thermal energy being transferred from one or more additional service devices into the working fluid of the refrigerant system to further heat the working fluid. The heated working fluid may then be transferred into another of the service devices from the working fluid via the 2-pipe bus. In some aspects, the working fluid of the refrigerant system may be directed to flow through one or multiple of the service devices in series, in parallel, or combinations thereof.

[0012] Some embodiments relate to a thermal management system. The system includes a service device positioned within a local environment. The system includes a compression refrigeration system (e.g., compressor 100, condenser 140, and evaporator 150) forming a refrigerant cycle loop. The compression refrigeration system is positioned outside of the local environment. A heat exchanger (e.g., application exchanger 160, 170, 180, 190) is thermally coupled with the service device. The system includes a 2-pipe bus. The 2-pipe bus is configured to selectively fluidly couple the heat exchanger with the refrigerant cycle loop at multiple different points along the refrigerant cycle loop of the compression refrigeration system. For example, valves (e.g., 1 12, 1 14, 1 16, 1 18) may be opened or closed to provide selective fluid coupling between the service device and the refrigerant cycle loop.

[0013] in some aspects, the 2-pipe bus is configured to selectively fluidly couple the heat exchanger with a heat source (e.g., evaporator) within the refrigerant cycle loop and with a heat sink (e.g., condenser) within the refrigeration cycle loop. The 2-pipe bus may be controllable (e.g., via controller/control unit) to define variable flow paths for a working fluid of the compression refrigeration system. For example, 3, 4, 5, 6, and 8 show examples of working fluid flow paths between service devices and the compression refrigeration system.

[0014] The 2-pipe bus may be controllable to define a flow path for the working fluid to exchange thermal energy with the service device. For example, the system may include a plurality of service devices positioned within the local environment, and a plurality of heat exchangers, such that each heat exchanger is thermally coupled with one of the plurality of service devices. The 2-pipe bus may be configured to selectively fluidly couple each heat exchanger with the refrigerant cycle loop at multiple (e.g., two) different points along the refrigerant cycle loop of the compression refrigeration system. For example, the heat exchanger may be fluidly coupled at one point upstream of a heat sink of the refrigerant cycle loop, and at another point downstream of the heat sink and upstream of a heat source of the refrigerant cycle loop. For example, the 2-pipe bus may provide fluid communication between the heat exchanger and the refrigerant cycle loop: (1) at a location that is downstream of the evaporator and upstream of the compressor; (2) at a location that is downstream of the compressor and upstream of the condenser; (3) at a location that is downstream of the condenser and upstream of the evaporator; or (4) combinations thereof.

[0015] In some aspects, the 2-pipe bus is controllable to define a flow path for the working fluid to exchange thermal energy between at least two service devices of the plurality of service devices. For example, a first of the plurality of service devices may be a heat sink and a second of the plurality of service devices may be a heat source. The 2-pipe bus may be controllable to define a flow path for the working fluid to extract thermal energy from the heat source and input at least a portion of the extracted thermal energy into the heat sink.

[0016] in some aspects, the disclosure provides for a thermal management system that includes a plurality of service devices positioned within a local environment, and a refrigeration system forming a refrigerant cycle loop. The refrigeration system is positioned outside of the local environment. The system includes a plurality of heat exchangers, with each heat exchanger thermally coupled with one of the service devices. The system also includes a 2-pipe bus that selectively fluidly couples each heat exchanger with the refrigerant cycle loop at two different points along the refrigerant cycle loop of the compression refrigeration system.

[0017] in another aspect, the disclosure provides for a method of transferring heat between service devices. The method includes thermally coupling each of a plurality of service devices positioned within a local environment with a heat exchanger, such that each sen/ice device is thermally coupled with at least one heat exchanger. The method includes providing a compression refrigeration system positioned outside of the local environment. The compression refrigeration system forms a refrigerant cycle loop. The method includes selectively fluidly coupling each heat exchanger with the refrigerant cycle loop of the compression refrigeration system at two different points along the refrigerant cycle loop using a 2-pipe bus.

BRIEF DESCRIPTION OF DRAWINGS

[0018] So that the manner in which the features and advantages of embodiments of the present disclosure may be understood in more detail, a more particular description of the briefly summarized embodiments above may be had by reference to the embodiments which are illustrated in the appended drawings that form a part of this specification. It is to be noted, however, that the drawings illustrate only various exemplary embodiments, and are therefore not to be considered limiting of the scope of this disclosure, as it may include other effective embodiments as well.

[0019] FIG. 1 is a diagram of a 2-pipe VFR system with a CHP and coupling for use with devices equipped with their own fluidic systems;

[0020] FIG. 2 is a component layout of the 2-pipe VFR system of FIG. 1;

[0021] FIG. 3 is a diagram of a 2-pipe VFR system demonstrating use of a heat-sinking device;

[0022] FIG. 4 is a diagram of a 2-pipe VFR system demonstrating use of a heat-sourcing device;

[0023] FIG. 5 is a diagram of 2-pipe VFR system demonstrating use with a vapor compression refrigeration system;

[0024] FIG. 6 is a component layout of the 2-pipe VFR system of FIG. 5;

[0025] FIGS. 7A-7G depict examples of fluid-to-fluid heat exchangers suitable for use in certain embodiments of the present disclosure;

[0026] FIG. 8 is a diagram of 2-pipe VFR system demonstrating use with water heater and an air conditioner;

[0027] FIG. 9 is a pressure-enthalpy (P-H) chart for R134a refrigerant as used in the system of FIG. 8; and

[0028] FIG. 10 is a diagram of 2-pipe VFR system demonstrating control of various portions thereof via a control unit.

DETAILED DESCRIPTION

[0029] Embodiments of the present disclosure will now be described more fully with reference to the accompanying drawings, which illustrate various exemplary embodiments. The disclosed concepts may, however, be embodied in many different forms and should not be construed as being limited by the illustrated embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough as well as complete and will fully convey the scope to those skilled in the art and modes of practicing the embodiments.

[0030] The present disclosure relates generally to methods, systems, and apparatus for balancing the thermal energy needs within a local environment. As used herein, a "local environment" may be defined as a discrete space with quantifiable thermal energy demands. For example, the local environment may be a residence, building, mobile enclosure or other facility or interior space thereof. It will become apparent to one skilled in the relevant engineering, architecture, or other technical art, that these aspects in part, or in their entirety, may be equally applicable to other settings and other applications.

[0031] Each of United States Patent Application Publication US 2015/0033778 Al and United States Patent Application Publication 2015/0128625 may serve as background for certain aspects of the present disclosure and are incorporated herein by reference in their entireties and made a part of the present disclosure. Moreover, at least some of the features and aspects described herein may be applicable to and\or incorporated with such systems and methods described therein.

[0032] Certain embodiments of the present disclosure relate to a high efficiency, refrigerant- based thermal management system (2-pipe VFR system) for independently controlling the direction and rate of refrigerant flow for multiple service devices within a controlled region or local environment.

[0033] FIG. 1 is a diagram of an embodiment of such a 2-pipe VFR system, and FIG. 2 is a simplified component layout of the 2-pipe VFR system of FIG. 1. With reference to FIGS. 1 and 2, the refrigerant-based thermal energy management system includes first distribution unit 101. First distribution unit 101 is an external unit located outside of a controlled region or local environment. First distribution unit 101 exchanges heat with the outside area (i.e., the area outside of the controlled region/local environment). First distribution unit 101 includes VFR compressor 100. In some embodiments, VFR compressor 100 is an electrically or mechanically driven variable speed compressor. First distribution unit 101 includes a gas phase valve array (valves 1 12, 1 14, 1 16, and 1 18) and a manifokl assembly (manifolds 1 10 and 120) having multiple ports that allow for dynamic selection of connection to either VFR compressor 100 suction (input) or output. In particular, first distribution unit 101 includes multi-port high- pressure manifold (HPM) 1 10, which is in operatively coupled to and in fluid communication with output of VFR compressor 100. First distribution unit 101 also includes multi-port low- pressure manifold (LPM) 120, which is operatively coupled to and in fluid communication with the input (suction) of VFR compressor 100. Valves 1 12, 1 14, 1 16 and 1 18 are operatively coupled to and in fluid communication with both HPM 1 10 and LPM 120. In some embodiments, valves 1 12, 1 14, 1 16 and 1 18 are each 3-way electronic expansion valves (EEV, solenoid valves).

[0034] First distribution unit 101 includes auxiliary condenser 140 operatively coupled to and in fluid communication with HPM 1 10 and with a liquid phase manifold having multiple ports, manifold 130. Condenser 140 is in fluid communication between HPM 1 10 and manifold 130. [0035] First distribution unit 101 includes auxiliary evaporator 150 operative ly coupled to and in fluid communication with both manifold 130 and LPM 120. Evaporator 150 is in fluid communication between manifold 130 and LPM 120. VFR compressor 100, HPM 1 10, condenser 140, manifold 130, evaporator 150, LPM 120, and valves (1 12, 1 14, 1 16, and 1 18) all channel a common working fluid, such that first distribution unit 101 forms a complete internal refrigerant cycle loop composed of VFR compressor 1 00, condenser 140 and evaporator 150.

[0036] The service devices suitable for use herein may include any of various devices that produce excess thermal energy, require input of thermal energy, or combinations thereof. In FIGS . 1 and 2, service device 165 is a condenser/compressor, service device 175 is an evaporator, service device 187 is a hot water heater, and service device 185 is a CHP module (e.g. , fossil fueled CHP module). Service devices are not limited to these particular embodiments and may include any of various heat-sinking and/or heat-sourcing devices, including one or more portions of a vapor compression refrigeration system.

[0037] Each service device (165, 175, 187, and 185) is operatively, fluidically, and or thermally coupled to first distribution unit 101 . Certain sen/ice devices channel the same common working fluid as first distribution unit 101, while other service devices may channel a different working fluid than first distribution unit 101 . For example, in FIG. 1 , service devices 165 and 175 channel different working fluids than first distribution unit 101. The working fluids of sendee devices 1 65 and 175, 165a and 175a, respectively, are thermally coupled with the common working fluid 101a of first distribution unit 101 via application exchangers 160 and 170, respectively. While, in FIG. 1 , service devices 187 and 185 channel the same common working fluid as first distribution unit 101 via application exchangers 180 and 190, respectively.

[0038] Thus, the 2-pipe VFR system disclosed herein does not require a third pipe (i. e. , is not a 3 -pipe system), and only includes two pipes connected to an application exchanger. The 2- pipe VFR system provides for independent control of both rate and direction of refrigerant flow (working fluid flow) for each individual indoor application exchanger (e.g. , heat exchanger). This is achieved by using a central mass and heat distribution unit that connects all the individual indoor application exchanger branches with a communal outdoor exchanger to redistribute refrigerant and heat flow, i.e., using distribution unit 101 composed of a series of manifolds ( 1 10, 1 12) and 3-way valves (1 12-1 18) to mechanically redistribute the working fluid. In some aspects, the 2-pipe VFR system does not include or use a branch circuit (BC) controller or phase separator to physically redistribute the working fluid, in some aspects, each branch and all indoor application exchangers of each branch may use a different refrigerant and/or heat flow direction than other branches of the system or other application exchangers within a branch.

[0039] As shown in FIG. 2, external refrigerant pump 176 may be operative ly coupled to and in fluid communication between service device 175 (evaporator) and application exchanger 170, and in fluid communication with service device 165 (condenser/compressor). While conventional type vapor compression (VC) air conditioning systems typically house a single refrigerant pump within the condenser unit, when the condenser and evaporator are split, as shown in FIG. 2, an additional pump may be used to circulate the working fluid between service devices 165 and 175.

[0040] In operation, application exchangers (160, 170, 180, and 190) are used to variably and selectively transfer heat either into or out of the service devices (165, 175, 187, and 185) in accordance with each service devices individual requirements at that time. The fluid flow rates and fluid flow direction of the common working fluid are controlled via the EEVs (112, 1 14, 116, and 1 18) and control unit 1 15 of first distribution unit 101. Control unit 1 15 may be an electrical control unit that provides the logic (hardware and software) for controlling and/or activating various components of first distribution unit 101, such as EEVs (112, 114, 1 16, and 118), VFR compressor 100, condenser 140, and/or evaporator 150. As such, heat may be transferred between AEs (160, 170, 180, and 190), and thereby service devices ( 165, 175, 187, and 185), in a manner that optimizes thermal balance of the service devices. During ideal conditions, when heat source and heat sink service devices are equal (i.e. , in thermal equilibrium), no waste heat is generated by the service devices. However, during non-ideal conditions, when heat source and heat sink service devices are unequal (i.e. , not in equilibrium), heat is either dumped (transferred) into or absorbed (transferred) from the system of service devices via auxiliary condenser 140 or evaporator 150, respectively. Thus, if one service device of the system of service devices is producing excess thermal energy, and another service device of the system of service devices is lacking thermal energy, the 2-pipe VFR system may be used to transfer the heat from the service device producing excess thermal energy into the service device that is lacking thermal energy. As such, the system uses thermal energy that may otherwise be lost in the form of waste heat to optimize thermal balance of the system of service devices.

[0041] FIG. 3 depicts a 2-pipe VFR system with a water heater, in accordance with certain embodiments. With reference to FIG. 3, service device 187 is a hot water heater. As shown by the flow path defined by the bold arrows in FIG. 3, the common working fluid leaves VFR compressor 100, and flows through HPM 1 10, condenser 140, and manifold 130 into hot water heater 187. Within hot water heater 187, an internal fluid type heat exchanger, application exchanger 180, operates to transfer heat from the common working fluid to water via conduction through the exchanger material. The thus cooled, common working fluid then returns to the suction side of VFR compressor 100 via EEV 1 16 and LPM 120.

[0042] FIG. 4 depicts a 2-pipe VFR system with a CHP unit in accordance with certain embodiments. With reference to FIG. 4, service device 185 is a fossil fueled CHP module. As shown by the flow path defined by the bold arrows in FIG. 4, the common working fluid leaves VFR compressor 100, and flows through HPM 1 10 and EEV 1 18 to application exchanger 190 where the high-pressure common working fluid expands and adsorbs heat from service device 185 within AE 190 (CPM internal heat exchanger). From AE 190, the common working fluid then returns to VFR compressor 100 via manifold 130, auxiliary evaporator 150, and LPM 120. In some embodiments (e.g. , embodiments shown in FIGS. 1 and 3), AE 190 (CPM internal heat exchanger) can be used to heat water within the water heater 187.

[0043] FIG. 5 depicts a 2-pipe VFR system with a vapor compression (VC) refrigeration unit, and FIG. 6 depicts a component layout of the 2-pipe VFR system of FIG. 5. With reference to FIGS . 5 and 6, the 2-pipe VFR system may accommodate a vapor compression cycle air conditioner, including a third-party device that has its own working fluid and was originally designed to work independently.

[0044] The 2-pipe VFR system of FIGS. 5 and 6 may be a combination of the heat sourcing and heat sinking operations described with references to FIGS. 1, 2 and 3 above, such that heat absorbed within evaporator 175 is exhausted via condenser 165, thereby allowing the system of service devices to work in a conventional manner with the 2-pipe system serving as a medium between the service devices.

[0045] As shown by the flow path defined by the bold arrows in FIG. 5, the high-pressure common working fluid exits VFR compressor 100, and flows through HPM 1 10 where the flow path splits, with a portion of the common working fluid traveling from HPM 1 10 through auxiliary condenser 140 and into AE 160 (condenser exchanger) via manifold 130, while a remaining portion of the common working fluid travels from HPM 1 10 through EEV 1 14 where the common working fluid expands for vaporization within AE 170 (exchanger). The common working fluid from both exchangers, AEs 160 and 170, then returns to VFR compressor 100 via LPM 120 and manifold 130, respectively. In the embodiment of FIG. 5, AEs 160 and 170 are separate dedicated units, affording heat transfer between the 2-pipe system and vapor compression systems (service devices) that utilize different refrigerants (working fluids).

[0046] Such a dual system combination allows older, legacy-type equipment (service devices) to be utilized with the 2-pipe system, while also leveraging the benefits of a flexible heat pump configuration, balanced heat distribution, and improved thermal efficiency. Specifically, service device 165 may either take the role of condenser 140 or be replaced by it to reduce capital and installation costs, while still allowing a duct type HVAC and existing evaporator system to be used in the system of service devices. Also, such a dual system combination allows for multiple use of the components thereof, such as using condenser 140 to thermally manage refrigerators or water coolers and using evaporator 150 to thermally manage hot water heaters.

[0047] FIGS . 7A-7G depict two examples of fluid type heat exchangers. Some embodiments may employ a shell-and-tube type exchanger 700 design (FIG. 7A) or a plate-type exchanger 750 (FIG. 7B). The exchangers may have single-pass or multi-pass (e.g. , two or four passes) arrangements. As exchanger construction and operation are well known to those or ordinary skill in the art, the arrangements will only be briefly described herein. FIG. 7C shows a single pass arrangement of a shell-and-tube type exchanger 700c showing the tubeside flow 710c, shell side flow 720c, and baffles 730c. FIG. 7D shows a two pass arrangement of a shell-and- tube type exchanger 700d showing the tubeside flow 710d and shell side flow 720d. FIG. 7E shows a four pass arrangement of a shell-and-tube type exchanger 700e showing the tubeside flow 710e and shell side flow 720e. FIG. 7F shows a single pass arrangement of a plate-type exchanger 750f, including fixed end 760f, movable end 765f, hot in 770f, hot out 775f, cold in 780f, and cold out 785f. FIG. 7G shows a multi pass arrangement of a plate-type exchanger 750g, including fixed end 760g, movable end 765g, hot in 770g, hot out 775g, cold in 780g, and cold out 785g.

[0048] The system described herein is not limited to the particular embodiments described herein. For example, the 2-pipe VFR system may be used with many different types of heat- operated devices, including 2-pipe designed devices with innate dedicated exchangers and third-party devices, given proper exchanger selection. Examples of service devices suitable for use with the 2-pipe VFR system include, but are not limited to, heat pumps, water heaters, water coolers, dehumidifiers, food warmers, clothes washers, clothes dryers, dish washers, refrigerators, components of HVAC systems, or combinations thereof. When used with the balanced, 2-pipe VFR system, such service devices may be operated at a reduced cost, or free of charge or substantially free of charge, by providing waste heat given up one service device for use with another service device when such thermally opposed equipment are operated simultaneously. As an example, consider a large (300 ft ² ) residential laundry/utility room requiring approximately 10,000 BTU/hour or 3kW for AC operation. A typical energy star rated electric heated clothes dryer runs at approximately 500W, and an electric clothes dryer runs at approximately 3kW. With conventional electrical system operation, the 3kW of AC waste heat is typically dumped to the outside atmosphere via a system condenser, while the 500W of clothes washing and 3kW of drying heat is generated electrically via the utility power grid, costing the user a total of 6kW while cooling the house and drying clothes. Using a 2- pipe system washer with a refrigerant water heater and a dryer with a refrigerant heated air blower (or a traditional system retrofitted with heat exchangers) allows the AC condenser heat to be used for washing and drying clothes, essentially doing laundry energy free (/ ^' . e. , providing energy to the washer and dryer from the AC condenser without drawing additional energy from the external electrical grid).

[0049] FIG. 8 is a diagram of the system, and FIG. 9 is a pressure-enthalpy (P-H) chart demonstrating an exemplary application of the 2-pipe VFR system. With reference to FIGS. 8 and 9, the independent heat flow characteristics of the central refrigerant component in the 2- pipe system is explained. However, one skilled in the art would understand that, in an actual installed system, efficiencies of the refrigerants in the devices would need to be considered for a complete evaluation of the thermal characteristics of the system, including the pressure and enthalpy characteristics of the system. For example, in an actual installed system, efficiencies of the refrigerant-water heat exchanger for the water heater 165 and blower of the air conditioners (e.g. , 180) would need to be considered.

[0050] As shown in FIG. 8, solenoid valves 1 14 and 1 18 are in the off position such that no refrigerant enters these channels. As such, branches 170 and 190 (i. e. , refrigerant flow paths or channels for these application heat exchangers) are thermodynamically isolated from the remainder of the system. Refrigerant flow path for 160 is thermally coupled with water heater 187, which absorbs heat from the system (i. e. , from the refrigerant within flow path 160). A heat pump cooler 185 (e.g. , air conditioner) within flow path 180 inputs heat into the system (i. e., refrigerant within flow path 180 absorbs heat from heat pump cooler 185). As shown in the accompanying P-H chart in FIG. 9, using R134a refrigerant as the working fluid in the 2- pipe VFR, fluid exiting the VFR pump 100 (compressor) is superheated gas at a temperature of 70 °C and a pressure of 1 MPa. This heated gas enters the high-pressure chamber 1 10 (manifold) and passes through solenoid valve 1 12, which directs the heated gas into thermal contact with the water heater 165 via flow path 160. As the heated gas is in thermal contact or communication with water heater 165, heat from the heated gas is transferred to water within the water heater 165. In some aspects, the process is heat is transferred from the heated gas to the water, ideally, in an isobaric process producing a liquid state at 0 °C. The refrigerant then flows from the water heater, and into expansion tank 130 (liquid phase manifold). Within expansion tank 130, the pressure and temperature of refrigerant further drop, producing a nearly 40% saturated state as shown in the P-H chart. In some aspects, within the expansion tank 130, the pressure of the refrigerant may be about 0.4 MPa and the temperature may be about 0 °C. From expansion tank 130, the refrigerant exits and flows in parallel through both the flow path passing through the external evaporator 150 and the flow path 190 that is thermally coupled with the air conditioner 185 ; thereby, absorbing thermal energy from both the indoor environment (i. e. , from the air conditioner 185) and from the outdoor environment (i. e. , via the evaporator 150) until the refrigerant becomes totally saturated within the low pressure tank 120 (manifold), which the refrigerant enters from both the external evaporator 150 and through the solenoid 1 16 on return from the air conditioner 185. Within the low-pressure tank 120, the refrigerant may be at a pressure of about 0.15 MPa and a temperature of about 0 °C. From the low-pressure tank 120, the refrigerant once again circulates through the VFR pump 100 to return to a superheated gas state, repeating the same flow path in a cycle.

[0051] In operation, the VFR pump 100 provides an adjustment to the flow rate of the refrigerant, such that a minimal amount of energy is expended to move the most amount of heat from a heat source to a heat destination.

[0052] Without being bound by theory, it is believed that in a perfectly balanced situation, refrigerant flow, water heating, and cooling rates within the system would be adjusted such that all of the heat absorbed from the air-conditioned environment of air conditioner 185 would be transferred to the water heater 165 to heat the water therein, without requiring any contribution of heat from the external condenser 140 or evaporator 150. Whereas, in an unbalanced condition resulting in deficient heat for water heating, heat absorbed from the air-conditioned environment of air conditioner 185 would be transferred to the water heater 165 to heat the water therein, but this heat would be supplemented by increased fluid flow rates and thermal absorption from evaporator 150, while excess heat would be compensated by ejection of heat from the condenser 150. Thus, the evaporator 150 and the condenser 140 compensate for insufficient or excess heat of the system, respectively.

[0053] Control Unit

[0054] With reference to FIG. 10, the control unit 1 15 disclosed herein may be a single element that includes a user interface. The user interface of control unit 1 15 includes display 1 17 for display of information and keypad 1 19 for input of information or control commands. One skilled in the art would understand that the user interface of the control unit disclosed herein is not limited to this particular arrangement.

[0055] Control unit 1 15 includes sensor inputs and control signal outputs for VFR pump 100; evaporator 150; condenser 140/manifold 130; and manifold 1 10/solenoid valves 1 12, 1 14, 1 16, 1 18.

[0056] VFR pump 100 is controlled via a feedback loop in which speed of the VFR pump 100 is sensed via sensors incorporated therewith, such as via hall effect, optical encoders, and/or back EMF sensors. Data signals from the sensor(s) incorporated into VFR pump 100 are transmitted via data link 102, such as CANBUS, to control unit 1 15. Control unit 1 15 may include algorithms to process the data signals and determine and transmit control commands to adjust the speed of the VFR pump 100, as needed. For example, control unit 1 15 may transmit a control signal to the VFR pump 100 to adjust the speed via motor drive 101 to maintain a speed set point of the VFR pump 100.

[0057] Control unit 1 15 also monitors the pressure and temperature of manifolds 1 10, 120 and 130 via sensor input data lines 1 1 1, 121 and 13 1, respectively, from pressure and temperature sensors incorporated with and/or in manifolds 1 10, 120, and 130. Control unit 1 15 processes the pressure and temperature data from manifolds 1 10, 120 and 130. If the pressure and/or temperature data from manifolds 1 10, 120 and 130 falls outside of set points or ranges, control unit 1 15 adjusts the VFR pump 100 speed, fan speed on evaporator 150, and fan speed on condenser 140 via sensor input and control driver lines 141 , 142, 15 1 , and 152. In some aspects, controller 1 15 is used to select the switch direction for solenoid valves 1 12, 1 14, 1 16, and 1 18 via control lines 1 13, 1 17, 1 19 and 123 ; thereby, determining the refrigerant flow direction for specific devices (e.g., application exchangers).

[0058] In some aspects, the interfaces 103 and 104 are composed of an array of panel mounted industry standard quick connect, compression or self-healing refrigerant couplings with brass or steel fittings and tubing, affording ready access and coupling of independent exchanger branches to the central distribution unit 101. However, one skilled in the art would understand that the interfaces 103 and 104 are not limited to this particular structure.

[0059] In some aspects, manifolds 1 10, 120 and 130 are composed of tubes or other conduits with main supply input and output ports and one or more ports for individual application exchanger connections, all realized using industry standard quick connect, compression or self- sealing refrigerant couplings. The fluid within in each manifold may be of uniform pressure, temperature and fluid composition and phase. One skilled in the art would understand that the manifolds are not limited to this particular structure.

[0060] The 2-pipe VFR system also includes second distribution unit 102. Second distribution unit 102 includes a series of one or more application exchangers (AE) 160, 170, 180 and 190. Each application exchanger ( 160, 170, 180 and 190) channels the same common working fluid as the first distribution unit 101. First and second distribution units 101 and 102 are thermally and fluidically interfaced via valves ( 1 12, 1 14, 1 16, and 1 18) and manifold 130, such as through interfaces 103 and 104, allowing fluid and thermal transfer between first and second distribution units 101 and 102. The 2-pipe VFR system provides a 2-pipe bus, allowing each service device ( 165, 175, 187, and 185) to be independently connected to one gas phase manifold port (one port of HPM 0 or LPM 120) and one liquid phase manifold port (one port of manifold 130). As such, sendee devices ( 165, 175, 187, and 185) are independently connected in parallel with either external unit condenser 140 or external unit evaporator 1 50.

[0061] The foregoing description has been presented for purposes of illustration and description of certain embodiments. This description is not intended to limit associated concepts to the various systems, apparatus, structures, and methods specifically described herein. Although specific system configurations are described, aspects of the systems, apparatus, processes, and methods described herein may be applicable or suitable in respect to other components and\or different mutual configurations not specifically illustrated or described herein. The embodiments described and illustrated herein are further intended to explain modes for practicing the system and methods, and to enable others skilled in the art to utilize same and other embodiments and with various modifications required by the particular applications or uses of the present embodiments.