Cooling unit and control system

Abstract

Cooling systems, such as refrigeration or air conditioning systems, utilize a two-phase refrigerant and capture heat in one environment (e.g., the interior of a building) and move the heat into a second environment (e.g., the exterior of a building). Such systems are often energy intensive even when the second environment is relatively cold. Systems, and preferably a single system, is provided to selectively provide mechanical cooling, free cooling, and optional heating utilizing the same refrigerant and substantially the same components.

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present application claims the benefit of Provisional U.S. Patent Application No. 63 / 633,876, entitled “Cooling Unit and Control System” filed on Apr. 15, 2024, which is incorporated herein by reference in its entirety and for all that it teaches.FIELD OF THE DISCLOSURE

[0002] The invention relates generally to systems and methods for cooling and heating an environment, wherein cooling is performed mechanically, wherein a refrigerant is compressed, or wherein a free-cooling mode omits compressing the refrigerant.BACKGROUND

[0003] Air conditioning systems rely on the refrigeration cycle utilizing a two-phase refrigerant. First, low-pressure, low-temperature refrigerant in a gaseous state enters the compressor, where it is compressed to a high-pressure, high-temperature gas. This high-pressure gas then flows into the condenser, where it releases heat to the surroundings and condenses into a high-pressure liquid. The high-pressure liquid refrigerant then passes through an expansion valve, where it rapidly expands, causing a drop in pressure and temperature. This low-pressure, low-temperature mixture of liquid and vapor then enters the evaporator, where it absorbs heat from the surrounding environment, causing the liquid to evaporate and turn back into a low-pressure gas. The cycle repeats and the low-pressure gas is returned to the compressor.

[0004] Most air-conditioned buildings require cooling only in the summer. During colder months air-conditioning is replaced with heating. However, many buildings generate a substantial amount of heat for their volume, such as data centers. As a result, cooling may be necessary year-round. When exterior air temperatures are below a threshold, an economizer may be utilized to provide cold air from the external environment. When air purity is essential, such as in data centers, the introduction of outside air requires additional air handlers and filtration before the cold exterior air can be introduced into the interior. As a result, even with cold exterior air temperatures, the compressor and / or additional air filtration components continue to draw electrical power and require additional maintenance to ensure proper operation and avoid introducing contaminants into the interior.SUMMARY

[0005] Prior art air conditioning systems work well in mechanical cooling mode, wherein the refrigerant is compressed by a compressor. In liquid overfeed type cooling, a pump is used to move low-temperature, low-pressure refrigerant to the evaporator and throughout the system. However, such systems require the use of a compressor even when exterior temperatures are low. Additionally, such systems are generally deployed as roof top air conditioners and not as heat pumps. As a result, when heating is needed, other systems must be available and are relied upon.

[0006] These and other needs are addressed by the various embodiments and configurations of the present invention. The present invention can provide a number of advantages depending on the particular configuration. These and other advantages will be apparent from the disclosure of the invention(s) contained herein.

[0007] In one embodiment, a flooded pumped-liquid overfeed evaporator replaces a prior art direct-expansion evaporator. The pumped liquid evaporator design greatly simplifies refrigerant distribution tubing requirements and allows stopping the compressor(s) “free cooling” at lower ambient temperatures without the need for air side economizer(s).

[0008] In another embodiment, such as in applications that do not require year-round cooling, systems and methods are provided to provide heating. Unlike air-source heat pumps, which typically cannot operate below an ambient air temperature of approximately 32° F., a cooling unit may operate in a heating mode that is independent of outdoor conditions. The unit provides heat without supplementary heating components, such as electric or gas-fired heaters, to operate below 32° F.

[0009] In some aspects, the techniques described herein relate to a system for providing multi-mode cooling, including: a number of refrigerant lines including a closed loop and connecting: a compressor including a compressor inlet and a compressor outlet; a condenser exposed to a first environment and including a condenser inlet and a condenser outlet; an expansion valve connected to the condenser outlet; a low-pressure receiver including a first low-pressure receiver outlet, a second low-pressure receiver outlet, a first low-pressure receiver inlet, and a second low-pressure receiver inlet and wherein the first low-pressure receiver inlet is connected to the expansion valve; a refrigerant pump including a pump inlet, connected to the first low-pressure receiver outlet, and a pump outlet; an evaporator exposed to a second environment and including an evaporator inlet and an evaporator outlet; a second refrigerant line connecting the pump outlet to the evaporator inlet; a third refrigerant line connected to the evaporator outlet and each of a first branch and a second branch, wherein the first branch is connected to a first refrigerant line and the second branch is connected to the second low-pressure receiver inlet; a fourth refrigerant line connecting the second low-pressure receiver outlet to the compressor inlet; and a first valve deployed on the second branch.

[0010] In some aspects, the techniques described herein relate to a system, wherein the system operates in a mechanical cooling mode including: energizing the compressor; energizing the condenser; modulating the expansion valve; and energizing the refrigerant pump; and energizing the evaporator wherein the first valve is open.

[0011] In some aspects, the techniques described herein relate to a system, wherein the system operates in a free cooling mode including: deenergizing the compressor; energizing the condenser; opening the expansion valve; and energizing the refrigerant pump; energizing the evaporator and wherein the first valve is closed.

[0012] In some aspects, the techniques described herein relate to a system, further including: a fifth refrigerant line connecting the first refrigerant line to the second refrigerant line; and a second valve deployed on the first refrigerant line between the condenser inlet and a junction, the junction connecting to the first branch of the third refrigerant line and the compressor outlet; wherein the system operates in a heating mode including: energizing the compressor; deenergizing the condenser; closing the expansion valve; and deenergizing the refrigerant pump; and wherein the first valve is open; and wherein the second valve is closed.

[0013] In some aspects, the techniques described herein relate to a system, further including a third valve deployed on the fifth refrigerant line, wherein operating in the heating mode includes modulating the third valve to create a pressure difference.

[0014] In some aspects, the techniques described herein relate to a system, further including: a sixth refrigerant line connecting the fifth refrigerant line to the first low-pressure receiver inlet; and a third valve deployed on the sixth refrigerant line; and wherein the third valve is closed when operating the system in the heating mode, closed when operating the system in a free cooling mode, and modulated when operating in a mechanical cooling mode; and wherein modulating the third valve is performed to maintain a minimum compressor load of the compressor.

[0015] In some aspects, the techniques described herein relate to a system, further including a check valve to prevent refrigerant from exiting the first refrigerant line via the first branch.

[0016] In some aspects, the techniques described herein relate to a system, further including a check valve preventing refrigerant from entering the compressor outlet.

[0017] In some aspects, the techniques described herein relate to a system, further including a check valve to prevent refrigerant from entering the pump outlet.

[0018] In some aspects, the techniques described herein relate to a system for providing multi-mode cooling, including: a number of refrigerant lines including a closed loop and connecting: a compressor; a condenser exposed to a first environment; an expansion valve; a low-pressure receiver; a refrigerant pump; and an evaporator exposed to a second environment; and wherein a compressor outlet of the compressor is connected to a first refrigerant line connected to a condenser inlet of the condenser; wherein a condenser outlet of the condenser is connected to an expansion valve inlet of the expansion valve; wherein an outlet of expansion valve is connected to a first low-pressure receiver inlet of the low-pressure receiver; wherein a first low-pressure receiver outlet of the low-pressure receiver is connected to a pump inlet of the refrigerant pump; wherein a pump outlet is connected to a second refrigerant line connected to an evaporator inlet of the evaporator; wherein an evaporator outlet connects to a third refrigerant line and a first branch of the third refrigerant line is connected to the first refrigerant line; and wherein a compressor inlet of the compressor is connected to a second low-pressure outlet of the low-pressure receiver.

[0019] In some aspects, the techniques described herein relate to a system, further including: a second branch of the third refrigerant line connected to a second low-pressure receiver inlet of the low-pressure receiver; and a first valve deployed on the second branch of the third refrigerant line; and wherein the system operates in a free cooling mode including: deenergizing the compressor; energizing the condenser; opening the expansion valve; and energizing the refrigerant pump; and wherein the first valve is closed.

[0020] In some aspects, the techniques described herein relate to a system, further including a check valve to prevent refrigerant from exiting the first refrigerant line via the first branch of the third refrigerant line.

[0021] In some aspects, the techniques described herein relate to a system, wherein the system operates in a mechanical cooling mode including: energizing the compressor; energizing the condenser; energizing the evaporator modulating the expansion valve; and energizing the refrigerant pump; and wherein the first valve is open.

[0022] In some aspects, the techniques described herein relate to a system, further including: a fourth refrigerant line connected to the first refrigerant line and to the low-pressure receiver; and wherein a hot gas bypass valve is deployed on the fourth refrigerant line and modulated to maintain minimum compressor load.

[0023] In some aspects, the techniques described herein relate to a system, further including: a fifth refrigerant line connecting the first refrigerant line to the second refrigerant line; and a second valve deployed on the first refrigerant line between the condenser inlet and a junction with the first branch of the third refrigerant line; wherein the system operates in a heating mode including: energizing the compressor; deenergizing the condenser; closing the expansion valve; and deenergizing the refrigerant pump; and wherein the first valve is open; and wherein the second valve is closed.

[0024] In some aspects, the techniques described herein relate to a system, further including a check valve preventing refrigerant from entering the compressor outlet.

[0025] In some aspects, the techniques described herein relate to a system, further including a check valve to prevent refrigerant from entering the pump outlet.

[0026] In some aspects, the techniques described herein relate to a method of operating a system to selectively heat or cool, including: operating the system in a mechanical cooling mode, including: compressing a refrigerant; thermally exposing the compressed refrigerant with a first environment; modulating the pressure of cooled refrigerant after exposure to the first environment; expanding the compressed refrigerant; pumping a liquid refrigerant portion of the expanded refrigerant to be exposed thermally a second environment; thermally exposing the expanded liquid refrigerant to the second environment and, as a result, obtaining therefrom a mixture of liquid refrigerant and gas refrigerant; returning the liquid refrigerant and gas refrigerant returning to a receiver.

[0027] In some aspects, the techniques described herein relate to a method, further including: operating the system in a free cooling mode, including: at least one of bypassing or omitting compressing the refrigerant; and wherein modulating the pressure of the cooled refrigerant is unrestricted; and diverting the gas refrigerant to be exposed to the first environment.

[0028] In some aspects, the techniques described herein relate to a method, further including: operating the system in a heating mode, including: at least one of bypassing or omitting each of: thermally exposing the compressed refrigerant to the first environment; modulating the pressure of the cooled refrigerant; expanding the compressed refrigerant; and pumping the liquid portion of the expanded refrigerant to be thermally exposed to the second environment; and thermally exposing the liquid refrigerant to the second environment.

[0029] One or more means for performing any one or more of the above or aspects of the embodiments described herein.

[0030] Any aspect in combination with any one or more other aspects.

[0031] Any one or more of the features disclosed herein.

[0032] Any one or more of the features as substantially disclosed herein.

[0033] Any one or more of the features as substantially disclosed herein in combination with any one or more other features as substantially disclosed herein.

[0034] Any one of the aspects / features / embodiments in combination with any one or more other aspects / features / embodiments.

[0035] Use of any one or more of the aspects or features as disclosed herein.

[0036] It is to be appreciated that any feature described herein can be claimed in combination with any other feature(s) as described herein, regardless of whether the features come from the same described embodiment.

[0037] The phrases “at least one,”“one or more,”“or,” and “and / or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B, and C,”“at least one of A, B, or C,”“one or more of A, B, and C,”“one or more of A, B, or C,”“A, B, and / or C,” and “A, B, or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B, and C together.

[0038] The term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more,” and “at least one” can be used interchangeably herein. It is also to be noted that the terms “comprising,”“including,” and “having” can be used interchangeably.

[0039] The term “automatic” and variations thereof, as used herein, refers to any process or operation, which is typically continuous or semi-continuous, done without material human input when the process or operation is performed. However, a process or operation can be automatic, even though performance of the process or operation uses material or immaterial human input, if the input is received before performance of the process or operation. Human input is deemed to be material if such input influences how the process or operation will be performed. Human input that consents to the performance of the process or operation is not deemed to be “material.”

[0040] The preceding is a simplified summary of the invention to provide an understanding of some aspects of the invention. This summary is neither an extensive nor exhaustive overview of the invention and its various embodiments. It is intended neither to identify key or critical elements of the invention nor to delineate the scope of the invention but to present selected concepts of the invention in a simplified form as an introduction to the more detailed description presented below. As will be appreciated, other embodiments of the invention are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below. Also, while the disclosure is presented in terms of exemplary embodiments, it should be appreciated that an individual aspect of the disclosure can be separately claimed.BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present disclosure is described in conjunction with the appended figures:

[0042] FIG. 1 depicts a first system in accordance with embodiments of the present disclosure;

[0043] FIG. 2 depicts a system in accordance with at least some embodiments of the present disclosure;

[0044] FIG. 3 depicts a system in accordance with at least some embodiments of the present disclosure;

[0045] FIG. 4 depicts a process in accordance with embodiments of the present disclosure;

[0046] FIG. 5 depicts a process in accordance with embodiments of the present disclosure;

[0047] FIG. 6 depicts a process in accordance with embodiments of the present disclosure; and

[0048] FIG. 7 depicts a process in accordance with embodiments of the present disclosure.DETAILED DESCRIPTION

[0049] The ensuing description provides embodiments only and is not intended to limit the scope, applicability, or configuration of the claims. Rather, the ensuing description will provide those skilled in the art with an enabling description for implementing the embodiments. It will be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the appended claims.

[0050] Any reference in the description comprising a numeric reference number, without an alphabetic sub-reference identifier when a sub-reference identifier exists in the figures, when used in the plural, is a reference to any two or more elements with the like reference number. When such a reference is made in the singular form, but without identification of the sub-reference identifier, it is a reference to one of the like numbered elements, but without limitation as to the particular one of the elements being referenced. Any explicit usage herein to the contrary or providing further qualification or identification shall take precedence.

[0051] The exemplary systems and methods of this disclosure will also be described in relation to components, controlling software, and / or hardware. However, to avoid unnecessarily obscuring the present disclosure, the following description omits well-known structures, components, and devices, which may be omitted from or shown in a simplified form in the figures or otherwise summarized.

[0052] For purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the present disclosure. It should be appreciated, however, that the present disclosure may be practiced in a variety of ways beyond the specific details set forth herein. For example, the embodiments herein illustrate a particular connection configuration of refrigerant lines. However, in other embodiments, connections may be made elsewhere and provide the same utility. For example, FIG. 1 illustrates refrigerant line 170 with junction 124 located between expansion valve 122 and first inlet 130 of low-pressure receiver 132. However, in other embodiments, functionally equivalent positioning is contemplated and may be implemented without departing from the scope of the embodiments, such as by providing the refrigerant line 170 from valve 172 directly to low-pressure receiver 132.

[0053] FIG. 1 depicts system 100 in accordance with at least some embodiments of the present disclosure. In one embodiment, system 100 comprises compressor 102, condenser 118, low-pressure receiver 132, evaporator 150, and additional components which will be described in greater detail with respect to the embodiments that follow.

[0054] In one embodiment, system 100 operates in a mechanical cooling mode. The mechanical cooling mode energizes compressor 102 to compress the refrigerant. High-pressure, high-temperature refrigerant exits compressor 102 at outlet 106 for cooling by condenser 118.

[0055] Condenser 118 provides thermal exposure to a first environment, most commonly ambient air, to cool the refrigerant. Line 112 between compressor outlet 106 and condenser inlet 116 is variously embodied and may include one or more of check valve 108, to prevent refrigerant from entering compressor 102 via outlet 106, junction 110, junction 174, and / or valve 114. Valve 114 may be omitted, thereby providing a direct line between junction 174 and inlet 116, or when present, valve 114 is open.

[0056] Condenser 118 may comprise electrically operated fans or other components to further promote cooling of the refrigerant. The refrigerant then exits condenser 118 via outlet 120 and expands in expansion valve 122 where it enters low-pressure receiver 132 via first inlet 130. Optionally, junction 124 may connect line 170 from valve 172 (described below). Low-pressure receiver 132 may be a known component receiving gaseous and / or liquid refrigerant. Gaseous refrigerant is drawn from the top (e.g., via outlet 128) and liquid refrigerant is drawn from the bottom (e.g., via outlet 134 attached to pump 140). Low-pressure receiver 132 may comprise a volume of both gaseous refrigerant and liquid refrigerant delineated by boundary 190. The exact position of boundary 190 may change during operation to comprise more gas / less liquid or vice versa.

[0057] Pump 140, via inlet 138, draws liquid refrigerant from low-pressure receiver 132 which exits via outlet 142 for exposure to a second environment, which may be the direct or indirect exposure to the air of the interior of a building and / or a heat exchanger utilized to cool the interior. Refrigerant may exit outlet 142 and pass through check valve 144 to prevent backflow into pump 140 and is provided to evaporator 150 via inlet 148. In mechanical cooling mode, refrigerant is prevented from entering line 162 by either capping or otherwise omitting line 162 between junction 146 and junction 160 or, when present, valve 164 is closed (illustrated with hashed lines).

[0058] Refrigerant exits evaporator 150 via outlet 152 connected to line 154 and may comprise a mixture of gaseous and liquid refrigerant. Line 154 connects to inlet 126 of low-pressure receiver 132 where liquid refrigerant is recycled via outlet 134 and gaseous refrigerant is drawn by compressor 102 via outlet 128. Valve 158 may be deployed on line 154 between junction 156, connecting to line 112, and inlet 126. Alternatively, inlet 126 may be attached to line 168. When present, valve 158 is open while system 100 is operating in mechanical cooling mode. Line 176 connects junction 156 to line 112 via junction 174. Check valve 180 may be utilized to prevent refrigerant from flowing from line 112.

[0059] Line 170 may be provided between junction 160 and junction 124, which may further comprise valve 172. Valve 172 is modulated to ensure that minimum compressor load on compressor 102 is maintained; line 170 is also known as a hot gas bypass.

[0060] Compressor 102 draws refrigerant from low-pressure receiver 132 via line 168 and inlet 104. The cycle of refrigerant repeats as necessary.

[0061] FIG. 2 depicts system 200 in accordance with at least some embodiments of the present disclosure. In one embodiment, system 200 illustrates an alternative configuration of system 100 (see FIG. 1) and comprises condenser 118, low-pressure receiver 132, evaporator 150, and additional components as described with respect to system 100. In another embodiment, system 200 alters the inclusion and / or exclusion of particular components of system 100 and / or the configuration of one or more components of system 100 to operate in free cooling mode. One notable difference between mechanical cooling of system 100 and free cooling of system 200 is the omission or de-energization of compressor 102 (illustrated with hashed lines).

[0062] Condenser 118 is energized (e.g., fans to promote thermal exposure of the refrigerant to the first environment). Expansion valve 122 is fully open or omitted. Pump 140 draws refrigerant from low-pressure receiver 132 which is provided to evaporator 150. In free cooling mode, refrigerant is prevented from entering line 162 by either capping or otherwise omitting line 162 between junction 146 and junction 160 or, when present, valve 164 is closed (illustrated with hashed lines).

[0063] Refrigerant is then provided to line 154. Refrigerant in line 154 is prevented from entering low-pressure receiver 132 via inlet 126, such as by closing valve 158 (illustrated with hashed lines) or capping or otherwise omitting the line between junction 156 and inlet 126. Refrigerant does not flow in line 170 ether by omitting line 170 or, when present, deploying valve 172 closed (illustrated with hashed lines). Refrigerant in line 154 then enters line 176 via junction 156 where it re-enters condenser 118 at inlet 116 and the cycle repeats as needed.

[0064] FIG. 3 depicts system 300 in accordance with at least some embodiments of the present disclosure. In one embodiment, system 300 illustrates an alternative configuration of system 100 (see FIG. 1) and comprises compressor 102, low-pressure receiver 132, evaporator 150, and additional components as described with respect to system 100. In another embodiment, system 300 alters the inclusion and / or exclusion of particular components of system 100 and / or the configuration of one or more components of system 100 to operate in heating mode. One notable difference between mechanical cooling of system 100 and heating system 300 is the omission or de-energization of condenser 118 and pump 140 (illustrated with hashed lines).

[0065] In one embodiment, refrigerant is compressed by compressor 102 and exits via outlet 106. Refrigerant does not enter line 176, such as due to capping or otherwise omitting line 176 or, when present, check valve 180. Condenser 118 and expansion valve 122 may be capped or otherwise omitted or, when present, isolated from refrigerant due to valve 114 being closed (illustrated with hashed lines). As a result, refrigerant in line 112 enters line 162 via junction 110. Line 162 may include valve 164 and, when present, valve 164 modulates to maintain, for example, a set pressure difference between line 162 and line 136. Refrigerant then joins line 136 at junction 146 to enter evaporator 150 at inlet 148. Pump 140 may be omitted or, when present, de-energized. When pump 140 is present, refrigerant is prevented from reaching pump 140 via check valve 144.

[0066] Refrigerant exiting evaporator 150 and outlet 152 enters line 154 and is provided to low-pressure receiver 132 via inlet 126. Line 154 may optionally provide valve 158 and, when present, valve 158 is open. Compressor 102 draws refrigerant from low-pressure receiver 132 via outlet 128 and line 168 via inlet 104, and the cycle repeats as needed.

[0067] FIG. 4 depicts process 400 in accordance with embodiments of the present disclosure. In one embodiment, a single set of components form a system of components that are selectively configured for one of three modes: heating, free cooling, and mechanical cooling. As a result, system 100 may be configured to operate as system 200 or system 300; system 200 may be configured to operate as system 100 or system 300; and system 300 may be configured to operate as system 100 or system 200. Accordingly, and in one embodiment, the single system may selectively alternate between the three modes by energizing / de-energizing certain components and / or operating (e.g., opening, closing, modulating) one or more valves regulating the flow of refrigerant on lines connecting the components) without physically adding or removing of lines or components. In another embodiment, components of the system are physically added or removed. For example, the system may be deployed in a warm location that never requires heating. As a result, components and configurations to accommodate heating may be physically omitted.

[0068] In one embodiment, test 402 determines if a call, such as from an interior of a building, is for heating or cooling. If the call is for cooling, test 406 determines if the temperature of a first environment, such as external air temperature, is above a threshold. If test 406 is determined in the negative, process 400 continues and operates the system in free cooling mode of process 600 (see FIG. 6). If test 406 is determined in the affirmative, process 400 continues and operates the system in mechanical cooling mode of process 500 (see FIG. 5). If test 402 determines the call is for heating, process 400 continues and operates the system in heating mode of process 700 (see FIG. 7). Process 400 may continue indefinitely or be terminated when no heating or cooling is required.

[0069] Test 406 is variously embodied. The particular threshold may be determined in accordance with the efficiency of the system when operating in mechanical cooling mode of process 500 versus free cooling mode of process 600. It should be appreciated that the external temperature may be embodied as atmospheric air, a water heat source / sink, and / or a location other than the location calling for heating or cooling. Generally, the location calling for heating or cooling is an internal space of a building but may be any space calling for heating or cooling, such as a room, portion of a room, container, or other space that is thermally isolated (in whole or in part) from the external environment.

[0070] FIG. 5 depicts process 500 in accordance with embodiments of the present disclosure. In one embodiment, process 500 operates a system (e.g., system 100) in mechanical cooling mode. It should be appreciated that process 500 is a cycle and a starting point (e.g., step 502) is provided as a convenience. The steps of process 500 may each be operated stepwise for a particular portion of refrigerant, as illustrated, or concurrently wherein each component continually performs a particular operation on a particular portion of the refrigerant.

[0071] Process 500 begins and, in step 502, a two-phase refrigerant is compressed. The refrigerant (now in a high-temperature, high-pressure state) is thermally exposed to a first environment, commonly but not exclusively, atmospheric air, in step 504. Step 504 cools the refrigerant, which may produce an erratic or undesired pressure. As a result, step 506 modulates the pressure, such as to maintain the minimum operating load of the compressor performing step 502 (e.g., compressor 102).

[0072] The refrigerant is then expanded in step 508, such as in a vessel (e.g., low-pressure receiver 132), which further lowers the temperature of a portion of the refrigerant in accordance with Boyle's Law. A pump may be deployed / energized to move the refrigerant. Any gaseous refrigerant is recycled and re-compressed in step 502. Liquid refrigerant is pumped to be exposed to a second environment, such as the interior of a building, in step 510, which may be performed by an evaporator (e.g., evaporator 150). As a result of step 510, the refrigerant may be a mixture of a gas and liquid. The gaseous portion of the refrigerant is re-introduced to step 502 and the liquid portion of the refrigerant is re-introduced to step 508.

[0073] FIG. 6 depicts process 600 in accordance with embodiments of the present disclosure. In one embodiment, process 600 operates a system (e.g., system 200) in free cooling mode. It should be appreciated that process 600 is a cycle and a starting point (e.g., step 602) is provided as a convenience. The steps of process 600 may each be operated stepwise for a particular portion of refrigerant, as illustrated, or concurrently wherein each component continually performs a particular operation on a particular portion of the refrigerant.

[0074] Process 600 begins and, in step 602, a two-phase refrigerant is condensed to a liquid. Step 602 may be performed, in whole or in part, by thermally exposing the two-phase refrigerant to a first environment (e.g., ambient air). Step 604 evaporates the liquid to a 2-phase refrigerant into a mixture of gas and liquid refrigerant. The liquid / gas refrigerant mixture may then be thermally exposed to a second environment, such as the interior of a building. The refrigerant is then re-introduced to step 602.

[0075] FIG. 7 depicts process 700 in accordance with embodiments of the present disclosure. In one embodiment, process 700 operates a system (e.g., system 300) in heating mode. It should be appreciated that process 700 is a cycle and a starting point (e.g., step 702) is provided as a convenience. The steps of process 700 may each be operated stepwise for a particular portion of refrigerant, as illustrated, or concurrently wherein each component continually performs a particular operation on a particular portion of the refrigerant.

[0076] Process 700 begins and, in step 702, a refrigerant gas is compressed and optionally heated. The refrigerant (now in a high-temperature, high-pressure state) is thermally exposed to a second environment, commonly the interior of a building, in step 704, which may be performed by an evaporator acting as a gas desuperheater (e.g., evaporator 150). Step 706 expands the refrigerant gas to lower the pressure and temperature, such as through a control valve, which lowers the temperature and pressure of the refrigerant in accordance constant enthalpy expansion of gas. The refrigerant is then re-introduced to step 702.

[0077] In the foregoing description, for the purposes of illustration, methods were described in a particular order. It should be appreciated that in alternate embodiments, the methods may be performed in a different order than that described without departing from the scope of the embodiments. It should also be appreciated that the methods described above may be performed as algorithms executed by hardware components (e.g., circuitry) purpose-built to carry out one or more algorithms or portions thereof described herein. In another embodiment, the hardware component may comprise a general-purpose microprocessor (e.g., CPU, GPU) that is first converted to a special-purpose microprocessor. The special-purpose microprocessor then having had loaded therein encoded signals causing the, now special-purpose, microprocessor to maintain machine-readable instructions to enable the microprocessor to read and execute the machine-readable set of instructions derived from the algorithms and / or other instructions described herein. The machine-readable instructions utilized to execute the algorithm(s), or portions thereof, are not unlimited but utilize a finite set of instructions known to the microprocessor. The machine-readable instructions may be encoded in the microprocessor as signals or values in signal-producing components by, in one or more embodiments, voltages in memory circuits, configuration of switching circuits, and / or by selective use of particular logic gate circuits. Additionally or alternatively, the machine-readable instructions may be accessible to the microprocessor and encoded in a media or device as magnetic fields, voltage values, charge values, reflective / non-reflective portions, and / or physical indicia.

[0078] Any of the steps, functions, and operations discussed herein can be performed continuously and automatically.

[0079] Also, while the flowcharts have been discussed and illustrated in relation to a particular sequence of events, it should be appreciated that changes, additions, and omissions to this sequence can occur without materially affecting the operation of the invention.

[0080] A number of variations and modifications of the embodiments can be used. It would be possible to provide for some features of the embodiments without providing others.

[0081] Embodiments herein comprising software are executed, or stored for subsequent execution, by one or more microprocessors and are executed as executable code. The executable code being selected to execute instructions that comprise the particular embodiment. The instructions executed being a constrained set of instructions selected from the discrete set of native instructions understood by the microprocessor and, prior to execution, committed to microprocessor-accessible memory. In another embodiment, human-readable “source code” software, prior to execution by the one or more microprocessors, is first converted to system software to comprise a platform (e.g., computer, microprocessor, database, etc.) specific set of instructions selected from the platform's native instruction set.

[0082] The present invention, in various embodiments, configurations, and aspects, includes components, methods, processes, systems and / or apparatus substantially as depicted and described herein, including various embodiments, subcombinations, and subsets thereof. Those of skill in the art will understand how to make and use the present invention after understanding the present disclosure. The present invention, in various embodiments, configurations, and aspects, includes providing devices and processes in the absence of items not depicted and / or described herein or in various embodiments, configurations, or aspects hereof, including in the absence of such items as may have been used in previous devices or processes, e.g., for improving performance, achieving ease, and\or reducing cost of implementation.

[0083] The foregoing discussion of the invention has been presented for purposes of illustration and description. The foregoing is not intended to limit the invention to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the invention are grouped together in one or more embodiments, configurations, or aspects for the purpose of streamlining the disclosure. The features of the embodiments, configurations, or aspects of the invention may be combined in alternate embodiments, configurations, or aspects other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment, configuration, or aspect. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0084] Moreover, though the description of the invention has included description of one or more embodiments, configurations, or aspects and certain variations and modifications, other variations, combinations, and modifications are within the scope of the invention, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights, which include alternative embodiments, configurations, or aspects to the extent permitted, including alternate, interchangeable and / or equivalent structures, functions, ranges, or steps to those claimed, whether or not such alternate, interchangeable and / or equivalent structures, functions, ranges, or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.

Claims

1. A system for providing multi-mode cooling, comprising:a number of refrigerant lines comprising a closed loop and connecting:a compressor comprising a compressor inlet and a compressor outlet;a condenser exposed to a first environment and comprising a condenser inlet and a condenser outlet;an expansion valve connected to the condenser outlet;a low-pressure receiver comprising a first low-pressure receiver outlet, a second low-pressure receiver outlet, a first low-pressure receiver inlet, and a second low-pressure receiver inlet and wherein the first low-pressure receiver inlet is connected to the expansion valve;a refrigerant pump comprising a pump inlet, connected to the first low-pressure receiver outlet, and a pump outlet;an evaporator exposed to a second environment and comprising an evaporator inlet and an evaporator outlet;a second refrigerant line connecting the pump outlet to the evaporator inlet;a third refrigerant line connected to the evaporator outlet and each of a first branch and a second branch, wherein the first branch is connected to a first refrigerant line and the second branch is connected to the second low-pressure receiver inlet;a fourth refrigerant line connecting the second low-pressure receiver outlet to the compressor inlet; anda first valve deployed on the second branch.

2. The system of claim 1, wherein the system operates in a mechanical cooling mode comprising:energizing the compressor;energizing the condenser;modulating the expansion valve; andenergizing the refrigerant pump; andenergizing the evaporatorwherein the first valve is open.

3. The system of claim 1, wherein the system operates in a free cooling mode comprising:deenergizing the compressor;energizing the condenser;opening the expansion valve; andenergizing the refrigerant pump;energizing the evaporatorandwherein the first valve is closed.

4. The system of claim 1, further comprising:a fifth refrigerant line connecting the first refrigerant line to the second refrigerant line; anda second valve deployed on the first refrigerant line between the condenser inlet and a junction, the junction connecting to the first branch of the third refrigerant line and the compressor outlet;wherein the system operates in a heating mode comprising:energizing the compressor;deenergizing the condenser;closing the expansion valve; anddeenergizing the refrigerant pump; andwherein the first valve is open; andwherein the second valve is closed.

5. The system of claim 4, further comprising a third valve deployed on the fifth refrigerant line, wherein operating in the heating mode comprises modulating the third valve to create a pressure difference.

6. The system of claim 4, further comprising:a sixth refrigerant line connecting the fifth refrigerant line to the first low-pressure receiver inlet; anda third valve deployed on the sixth refrigerant line; andwherein the third valve is closed when operating the system in the heating mode, closed when operating the system in a free cooling mode, and modulated when operating in a mechanical cooling mode; andwherein modulating the third valve is performed to maintain a minimum compressor load of the compressor.

7. The system of claim 1, further comprising a check valve to prevent refrigerant from exiting the first refrigerant line via the first branch.

8. The system of claim 1, further comprising a check valve preventing refrigerant from entering the compressor outlet.

9. The system of claim 1, further comprising a check valve to prevent refrigerant from entering the pump outlet.

10. A system for providing multi-mode cooling, comprising:a number of refrigerant lines comprising a closed loop and connecting:a compressor;a condenser exposed to a first environment;an expansion valve;a low-pressure receiver;a refrigerant pump; andan evaporator exposed to a second environment; andwherein a compressor outlet of the compressor is connected to a first refrigerant line connected to a condenser inlet of the condenser;wherein a condenser outlet of the condenser is connected to an expansion valve inlet of the expansion valve;wherein an outlet of expansion valve is connected to a first low-pressure receiver inlet of the low-pressure receiver;wherein a first low-pressure receiver outlet of the low-pressure receiver is connected to a pump inlet of the refrigerant pump;wherein a pump outlet is connected to a second refrigerant line connected to an evaporator inlet of the evaporator;wherein an evaporator outlet connects to a third refrigerant line and a first branch of the third refrigerant line is connected to the first refrigerant line; andwherein a compressor inlet of the compressor is connected to a second low-pressure outlet of the low-pressure receiver.

11. The system of claim 10, further comprising:a second branch of the third refrigerant line connected to a second low-pressure receiver inlet of the low-pressure receiver; anda first valve deployed on the second branch of the third refrigerant line; andwherein the system operates in a free cooling mode comprising:deenergizing the compressor;energizing the condenser;opening the expansion valve; andenergizing the refrigerant pump; andwherein the first valve is closed.

12. The system of claim 11, further comprising a check valve to prevent refrigerant from exiting the first refrigerant line via the first branch of the third refrigerant line.

13. The system of claim 11, wherein the system operates in a mechanical cooling mode comprising:energizing the compressor;energizing the condenser;energizing the evaporatormodulating the expansion valve; andenergizing the refrigerant pump; andwherein the first valve is open.

14. The system of claim 13, further comprising:a fourth refrigerant line connected to the first refrigerant line and to the low-pressure receiver; andwherein a hot gas bypass valve is deployed on the fourth refrigerant line and modulated to maintain minimum compressor load.

15. The system of claim 11, further comprising:a fifth refrigerant line connecting the first refrigerant line to the second refrigerant line; anda second valve deployed on the first refrigerant line between the condenser inlet and a junction with the first branch of the third refrigerant line;wherein the system operates in a heating mode comprising:energizing the compressor;deenergizing the condenser;closing the expansion valve; anddeenergizing the refrigerant pump; andwherein the first valve is open; andwherein the second valve is closed.

16. The system of claim 10, further comprising a check valve preventing refrigerant from entering the compressor outlet.

17. The system of claim 10, further comprising a check valve to prevent refrigerant from entering the pump outlet.

18. A method of operating a system to selectively heat or cool, comprising:operating the system in a mechanical cooling mode, comprising:compressing a refrigerant;thermally exposing the compressed refrigerant with a first environment;modulating the pressure of cooled refrigerant after exposure to the first environment;expanding the compressed refrigerant;pumping a liquid refrigerant portion of the expanded refrigerant to be exposed thermally a second environment;thermally exposing the expanded liquid refrigerant to the second environment and, as a result, obtaining therefrom a mixture of liquid refrigerant and gas refrigerant;returning the liquid refrigerant and gas refrigerant returning to a receiver.

19. The method of claim 18, further comprising:operating the system in a free cooling mode, comprising:at least one of bypassing or omitting compressing the refrigerant; andwherein modulating the pressure of the cooled refrigerant is unrestricted; anddiverting the gas refrigerant to be exposed to the first environment.

20. The method of claim 18, further comprising:operating the system in a heating mode, comprising:at least one of bypassing or omitting each of:thermally exposing the compressed refrigerant to the first environment;modulating the pressure of the cooled refrigerant;expanding the compressed refrigerant; andpumping the liquid portion of the expanded refrigerant to be thermally exposed to the second environment; andthermally exposing the liquid refrigerant to the second environment.

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