Refrigerant discharge heat exchange system and method

A desuperheater of a heating, ventilation, and/or air conditioning (HVAC) system includes a first conduit defining a first fluid flow path configured to receive a refrigerant, and a second conduit defining a second fluid flow path and configured to facilitate heat transfer between the first fluid flow path and the second fluid flow path. The desuperheater also includes an inlet of the second conduit configured to receive collected water into the second fluid flow path. The desuperheater also includes a ventilation hole disposed in the second conduit and configured to vent water vapor from the second fluid flow path.

BACKGROUND

Heating, ventilation, and/or air conditioning (HVAC) systems are utilized in residential, commercial, and industrial environments to control environmental properties, such as temperature and humidity, for occupants of the respective environments. An HVAC system may control the environmental properties of an environment through the control of an airflow delivered to the environment. For example, certain HVAC systems may utilize a vapor compression cycle whereby a refrigerant is compressed by a compressor, condensed by a condenser, expanded by an expansion valve, and routed through an evaporator in which the refrigerant absorbs heat from an air flow blown or drawn over the evaporator. The vaporized refrigerant may then be routed back to the compressor, and the cooled air flow may be directed toward the environment for conditioning the environment.

In traditional embodiments, the refrigerant may be superheated by the compressor and may include other temperature or pressure properties caused by the above-described HVAC components that negatively impact, for example, an efficiency and/or life time of the HVAC system.

SUMMARY

The present disclosure relates to a desuperheater of a heating, ventilation, and/or air conditioning (HVAC) system. The desuperheater includes a first conduit defining a first fluid flow path configured to receive a refrigerant, and a second conduit defining a second fluid flow path and configured to facilitate heat transfer between the first fluid flow path and the second fluid flow path. The desuperheater also includes an inlet of the second conduit configured to receive collected water into the second fluid flow path. The desuperheater also includes a ventilation hole disposed in the second conduit and configured to vent water vapor from the second fluid flow path.

The present disclosure also relates to a heating, ventilation, and/or air conditioning (HVAC) system. The HVAC system includes a discharge line through which a refrigerant flows, and a casing surrounding a portion of the discharge line and defining a second fluid flow path between the casing and the portion of the discharge line. The casing includes an inlet configured to receive collected water into the second fluid flow path, and the casing includes ventilation holes configured to vent water vapor from the second fluid flow path.

The present disclosure also relates to a desuperheater of a heating, ventilation, and/or air conditioning (HVAC) unit. The desuperheater includes a conduit defining a first fluid flow path configured to receive a refrigerant. The desuperheater also includes a casing surrounding the conduit and defining a second fluid flow path between the casing and the conduit, where the casing includes an inlet configured to receive condensate water, rain water, or both into the second fluid flow path. The desuperheater also includes a plate disposed adjacent an inlet of the second fluid flow path and configured to enable, in response to thermal expansion of the plate, a flow of the condensate water, the rain water, or both through the inlet and into the second fluid flow path.

DETAILED DESCRIPTION

The present disclosure is directed toward a heat exchanger configured to cool a refrigerant discharge from a compressor or condenser. More particularly, the present disclosure is directed toward a desuperheater configured to desuperheat a refrigerant discharge from a compressor or condenser.

Certain HVAC systems may include a compressor configured to compress a refrigerant. In one example, an HVAC system includes a vapor compression cycle having a compressor configured to compress the refrigerant to generate superheated vapor, a condenser configured to receive the compressed refrigerant and to condense the compressed refrigerant from a gaseous to a saturated liquid state, an expansion valve configured to receive the condensed refrigerant and to expand the refrigerant, and an evaporator configured to receive the expanded refrigerant and to utilize the expanded refrigerant to cool an air flow blown or drawn over the evaporator. It is now recognized that, in certain systems, the superheated vapor generated by the compressor may reduce an efficiency or life cycle of the HVAC system. In accordance with present embodiments, the efficiency or life cycle of the HVAC system may be improved by desuperheating the refrigerant.

In accordance with present embodiments, a desuperheater may be configured to receive the refrigerant discharged from the compressor or the condenser. In some embodiments, the HVAC system may include two installations of the presently disclosed desuperheater, one downstream from the compressor and another downstream from the condenser. The presently disclosed desuperheater may be configured to receive the refrigerant discharge, and to cool the refrigerant discharge via cooling water including rain water, condensate water, or both.

For example, the desuperheater may include a first conduit, which may be a casing, surrounding a second conduit, where the first conduit is configured to receive the refrigerant discharge from the compressor. The casing may define a flow path between the casing and an outer surface of the conduit, whereby the flow path is configured to receive the cooling water. Heat exchange fins may be disposed within the flow path configured to receive the cooling water. For example, the heat exchange fins may be coupled to, or integrally formed with, the conduit along the outer surface of the conduit. The cooling water may extract heat from the refrigerant flowing through the conduit, for example via conductive heat transfer from the conduit and/or the heat exchange fins, and the cooling water may be output through an outlet of the desuperheater. In some embodiments, the casing may include ventilation holes in an upper end of the casing. The ventilation holes may be configured to enable venting of water vapor generated during the above-described heat transfer.

Further, the desuperheater may include an inlet valve configured to control a flow of the cooling water through an inlet of the desuperheater to the flow path defined between the casing and the outer surface of the conduit, for example to enable or disable the flow to the inlet. In some embodiments, the valve may include a bi-metallic plate formed by a first metallic portion having a first coefficient of thermal expansion and a second metallic portion having a second coefficient of thermal expansion different than the first coefficient of thermal expansion. The first and second metallic portions may be bound together by fixed connections on opposing ends of the bi-metallic plate. That is, the first and second metallic portions may be stacked together, one on top of the other, and fixed connections may extend around both of the first and second metallic portions at opposing ends of the bi-metallic plate. The bi-metallic plate may thermally expand as a temperature of the bi-metallic plate is increased. The temperature of the bi-metallic plate may be increased via changes to an atmospheric or environmental temperature surrounding the bi-metallic plate. Since the first and second metallic portions of the bi-metallic plate include different coefficients of thermal expansion, the first metallic portion may thermally expand more quickly than the second metallic portion in response to an increased temperature.

By including metallic portions with different coefficients of thermal expansion, and by binding the metallic portions via the above-described fixed connections, thermal expansion may cause the bi-metallic plate to warp. The warping may be leveraged to enable the flow of cooling water into the desuperheater or disable the flow of the cooling water into the desuperheater based on the temperature of the bi-metallic plate, which is based on the environmental temperature as noted above. Accordingly, the flow of the cooling water into the flow path of the desuperheater may be disabled in low temperature conditions that may otherwise cause freezing of the cooling water within the desuperheater. That is, the inlet valve having the bi-metallic plate may be utilized to block pipe freezing conditions in winter months, or when environmental temperature is low and could cause freezing. These and other features will be described in detail below with reference to the drawings.

Turning now to the drawings,FIG. 1illustrates an embodiment of a heating, ventilation, and/or air conditioning (HVAC) system for environmental management that may employ one or more HVAC units. As used herein, an HVAC system includes any number of components configured to enable regulation of parameters related to climate characteristics, such as temperature, humidity, airflow, pressure, air quality, and so forth. For example, an HVAC system as used herein is defined as conventionally understood and as further described herein. Components or parts of an HVAC system may include, but are not limited to, all, some of, or individual parts such as a heat exchanger, a heater, an airflow control device, such as a fan, a sensor configured to detect a climate characteristic or operating parameter, a filter, a control device configured to regulate operation of an HVAC system component, a component configured to enable regulation of climate characteristics, or a combination thereof. An HVAC system is a system configured to provide such functions as heating, cooling, ventilation, dehumidification, pressurization, refrigeration, filtration, or any combination thereof. The embodiments described herein may be utilized in a variety of applications to control climate characteristics, such as residential, commercial, industrial, transportation, or other applications where climate control is desired.

As set forth above, embodiments of the present disclosure are directed toward a heat exchanger configured to cool a refrigerant discharge from a compressor or condenser. More particularly, the present disclosure is directed toward a desuperheater configured to desuperheat a refrigerant discharge from a compressor or condenser. The desuperheater is incorporated into each ofFIGS. 1-4above, as described in detail below with reference toFIGS. 5-14. In general, the desuperheater may receive a compressed refrigerant and recycled rain and/or condensate water, and may route the compressed refrigerant and recycled rain and/or condensate water in a heat exchange relation to one another. That is, the desuperheater may utilize the recycled rain and/or condensate water to cool the compressed refrigerant. The desuperheater may include heat exchange fins to improve heat transfer, and ventilation openings to enable water vapor to exit the desuperheater. Further, the desuperheater may include a valve, such as a bi-metallic valve, configured to block a flow of the recycled rain and/or condensate water in temperature conditions that could cause frozen pipes if not for the valve. These and other features of the desuperheater will be discussed in detail below, with reference toFIGS. 5-14.

FIG. 5is a schematic of an embodiment of a portion of a vapor compression system172having at least one desuperheater200. In the illustrated embodiment, the vapor compression system172includes a compressor174, a condenser176, an expansion valve178, and an evaporator180. Operation of the vapor compression system172is similar to, or the same as, the vapor compression system72described above with respect toFIG. 4. In the illustrated embodiment, the vapor compression system172includes two desuperheaters200, one positioned between the compressor174and the condenser176, and the other positioned between the condenser200and the expansion valve178.

Focusing first on the embodiment disposed between the compressor174and the condenser176, the desuperheater200may be configured to receive rain water gathered in a rain collection pan202, condensate water gathered in a drain pan204, or both. The rain water and/or the condensate water may be referred to collectively or individually as collected water. The desuperheater200may include a conduit201configured to receive compressed refrigerant from a compressor discharge line197of the compressor174. The compressed refrigerant may be superheated by the compressor174, and the desuperheater200may be configured to cool, or desuperheat, the compressed refrigerant. The desuperheater200also includes a casing203, which may be referred to as an additional conduit, surrounding the conduit201. A water flow path may be defined between the casing203and an outer surface of the conduit201. The water flow path defined between the casing203and the conduit201may be configured to receive the condensate water from the drain pan204, the rain water from the rain collection pan202, or both. In certain embodiments, a pump206may be employed to pump condensate water from the condensate collection pan204to the desuperheater200, either directly or first through the rain collection pan202. A similar pump may be utilized in another embodiment for pumping water in an opposing direction or route, for example to pump the rain water toward the condensate collection pan204. As the desuperheater guides the rain and/or condensate water through the water flow path and the refrigerant through the conduit201, heat may be transferred from the compressed refrigerant to the rain and/or condensate water, thereby cooling the compressed refrigerant.

The desuperheater200downstream of the condenser176may operate in the same or a similar manner. That is, the refrigerant exiting the condenser176may be superheated or heated above a desired temperature, and the desuperheater200receiving the refrigerant from a condenser discharge line199of the condenser176may operate to cool the refrigerant. The conduit201may receive the condensed refrigerant, and the flow path between the casing203and the conduit201may receive the rain and/or condensate water. As will be described in detail below with respect to later drawings, a valve may control water input to the desuperheater200, an outlet may enable the water to exit the desuperheater200, and ventilation openings may enable water vapor to exit the water flow path of the desuperheater200during operation of the desuperheater.

In certain embodiments, the conduit201of the desuperheater200may be integral with the compressor discharge line197or the condenser discharge line199, and the casing203may be formed or disposed around the conduit201. In other embodiments, the conduit201may be separate from the compressor discharge line197or the condenser discharge line199. For example, the conduit201may be separate from the discharge line197or199and may include a different material having a higher heat transfer coefficient than the discharge line197or199. Including the conduit201having the material with the higher heat transfer coefficient may as described above may enhance a cooling effect of the desuperheater200.

FIG. 6is a perspective view of an embodiment of the desuperheater200ofFIG. 5. As shown, the desuperheater includes a valve210configured to enable or disable a flow of the rain and/or condensate water to an inlet212of the desuperheater200, more specifically to the inlet212of the water flow path disposed between the casing203of the desuperheater200and the conduit201of the desuperheater. The conduit201fluidly separates the refrigerant from the space in the desuperheater200between the conduit201and the outer casing203. Thus, a flow of condensate and/or rain water in the space between the conduit201and the casing203does not mix with the refrigerant. The casing203includes ventilation openings216facing upwardly, with respect to gravity, and configured to enable water vapor to vent from the desuperheater200. For example, as the water flowing through the desuperheater200extracts heat from the refrigerant flowing through the desuperheater200, a portion of the water may be vaporized. The ventilation openings216in the illustrated embodiment are disposed only on an upwards facing segment of the casing203, such that liquid water within the desuperheater200does not flow through the ventilation openings216. Instead, the liquid water is guided toward a downward facing outlet213of the desuperheater, and in some embodiments through an outlet line214coupled to the outlet213. The outlet line214may safely dispose of the water, or the outlet line214may route the water toward a drain pan or rain collection pan to recycle the water. In general, the ventilation openings216may safely remove water vapor from the water flow path, which enhances heat transfer and, thus, effectiveness of the desuperheater200.

FIG. 7is a cross-sectional axial view of an embodiment of the desuperheater200ofFIG. 6, taken along line7-7inFIG. 6. A water flow path222, which is configured to receive the rain and/or condensate water via the inlet212of the desuperheater200, is shown in the illustrated embodiment. As previously described, the water flow path222is configured to receive the condensate and/or rain water, and is separated from a flow of the refrigerant via the conduit201of the desuperheater200. That is, the water flow path222may be defined between an outer surface217of the conduit201and an inner surface219of the casing203. As shown, heat exchange fins218of the desuperheater200may extend within the water flow path222. In some embodiments, the heat exchange fins218may include a material with a relatively high heat transfer coefficient, such as certain metallic materials. The conduit201may also include a material with a high heat transfer coefficient, and the heat exchange fins218may couple to, or be integrally formed with, the conduit201. Accordingly, heat may be transferred from the refrigerant, to the conduit201, and to the water, and/or from the refrigerant, to the conduit201, to the heat exchange fins218, and to the water. The heat exchange fin (or fins)218may be disposed in a helical arrangement, a spiral arrangement, a swirl arrangement, a threaded arrangement, or some other arrangement configured to improve heat transfer, as will be described with reference to later drawings. For example, in the illustrated embodiment, a single heat exchange fin218may extend in a spiral or helical route about the conduit201, which may increase an amount of time the water takes to travel from the inlet212to the desuperheater200, through the water flow path222of the desuperheater200, and to the outlet213of the desuperheater200.

FIG. 8is a cross-sectional radial view of an embodiment of the desuperheater ofFIG. 6. In the illustrated embodiment, the desuperheater200includes several heat exchange fins218extending within the water flow path222. For example, each heat exchange fin218may include a curved profile along an axial cross-section through the desuperheater200, as shown, and the curved profile may extend in a linear direction from one end of the desuperheater200to the other. That is, each fin218may extend in an axial direction along a longitudinal axis221extending through the conduit201of the desuperheater200. In the illustrated embodiment, each fin218includes perforations224to enable the water to flow from one side of the fin218to the other. The perforations224may include circular holes, slots extending in the axial direction along the longitudinal axis221, or both.

FIG. 9is another cross-sectional radial view of an embodiment of the desuperheater200ofFIG. 6. In the illustrated embodiment, the desuperheater200includes several heat exchange fins218extending within the water flow path222. Each heat exchange fin218includes a substantially straight cross-sectional profile in a radial direction relative to the longitudinal axis221. However, each fin218may twist about the longitudinal axis221as the fin218extends along the longitudinal axis221from one end of the desuperheater200to the other. The fins218in the illustrated embodiment may include perforations224.

In each ofFIGS. 7-9, the ventilation openings216are disposed through an upwards facing segment227of the desuperheater200relative to gravity, and the water outlet213is disposed in a downward facing segment229of the desuperheater200. Accordingly, spent water can be routed out of the desuperheater200via the outlet213, and water vapor can be vented from the desuperheater200via the ventilation openings216. By venting the water vapor, the desuperheater200can more readily receive additional water for cooling the refrigerant flowing through the conduit201. That is, the ventilation openings216disposed in the upwards facing segment227, by venting water vapor, improves heat transfer effectiveness of the desuperheater200.

As illustrated in, and previously described with respect to,FIG. 6, a valve210of the desuperheater200may be utilized to enable or disable a flow of the water to or through the desuperheater200. For example, in low temperature conditions, the inlet valve210may block a flow of the condensate and/or rain water to the desuperheater200in order to block pipe freezes.FIG. 10is a schematic of an embodiment of the inlet valve210formed by a bi-metallic plate211, for use in the desuperheater200ofFIG. 6, and for blocking a flow of water through a supply water line215. That is, the supply water line215inFIG. 10may supply rain and/or condensate water to a desuperheater, as previously described, and the illustrated bi-metallic plate211may be used to enable or disable the flow of water through the supply water line215.

The bi-metallic plate211of the inlet valve210inFIG. 10includes a first metallic portion236and a second metallic portion238. The first metallic portion236may include a first coefficient of thermal expansion, and the second metallic portion238may include a second coefficient of thermal expansion different than the first coefficient of thermal expansion of the first metallic portion236. The first metallic portion236and the second metallic portion238may be coupled via fixed connections239on either end232,234of the bi-metallic plate211of the inlet valve210, where the ends232,234refer to either end of a length230of the bi-metallic plate211. At relatively low temperatures, the bi-metallic plate211may include a substantially straight orientation, as the relatively low temperature is not high enough to cause either of the portions236,238to thermally expand. The illustrated inFIG. 10corresponds to a state of the bi-metallic plate211at a relatively low temperature.

As a temperature surrounding the bi-metallic plate211of the inlet valve210increases, the first metallic portion236may thermally expand at a faster rate, or beginning at a lower temperature, than the second metallic portion238. Because the first metallic portion236and the second metallic portion238include fixed connections239and the first metallic portion236thermally expands in response to a lower temperature than the second metallic portion238, the bi-metallic plate211of the inlet valve210may warp as a temperature surrounding it increases.FIG. 11is a schematic of an embodiment of the inlet valve210ofFIG. 10after thermal expansion of the bi-metallic plate211. As the bi-metallic plate211of the inlet valve210warps, a flow of the water past the bi-metallic plate211and through the supply water line215may be enabled. That is, the flow of water may be permitted at higher temperatures that cause the bi-metallic plate211of the inlet valve210to warp, and may be blocked at lower temperatures when the bi-metallic plate211of the inlet valve210does not warp. A feature223of the supply water line215, such as a flexible or hinged flap, may enable the bi-metallic plate211to restrict a flow path of the supply water line215when the bi-metallic plate211is in the unexpanded state illustrated inFIG. 10. The feature223, such as the flexible or hinged flap, may be repositioned as the bi-metallic plate211flexes or bends away from the supply water line215at relatively high temperatures, thereby enabling a flow of water through the supply water line215, as illustrated inFIG. 11. Thus, the inlet valve210may be an entirely mechanical device formed by the bi-metallic plate211, which can enable or disable a flow of the water through the supply water line215and to an inlet of a desuperheater without electric or electronic power and control.

FIG. 12is a schematic of an embodiment of the inlet valve210formed by the bi-metallic plate211and an actuator240. In the illustrated embodiment, the bi-metallic plate211may operate in a similar manner as described above with respect toFIGS. 10 and 11, but the inlet valve210may include the actuator240, which is configured to enable or disable the flow of water based on a contact between the bi-metallic plate211and the actuator240. That is, the bi-metallic plate211may warp in response to a temperature increase described above, causing the bi-metallic plate211to contact the actuator240.FIG. 13is a schematic of an embodiment of the inlet valve ofFIG. 12after thermal expansion of the bi-metallic plate211, whereby the bi-metallic plate211contacts the actuator240. In response to the contact, the actuator240may enable the flow of water to the desuperheater. The actuator240may be a mechanical device such as a gate or switch, or an electric or electronic device.

FIG. 14is a schematic of an embodiment of a controller82, for example having a processor and memory as described above with respect toFIG. 4, and an inlet valve210for use in the desuperheater ofFIG. 6. In the illustrated embodiment, the controller82may receive sensor feedback from a sensor242, such as a temperature sensor, and may control opening and closing of the inlet valve210based on the temperature surrounding the valve210and/or desuperheater.

As described above, and in accordance with the present disclosure, a desuperheater of a vapor compression system may be utilized to desuperheat a compressed and/or condensed refrigerant. The desuperheater may include heat exchange fins configured to enhance heat transfer between the refrigerant and recycled rain and/or condensate water. The desuperheater may also include ventilation openings configured to enable water vapor to vent from a water flow path of the desuperheater. The desuperheater may also include an inlet valve, such as a bi-metallic plate, that enables or disables a flow of water into the desuperheater based on a temperature surrounding the desuperheater. Thus, frozen pipe conditions are blocked by the inlet valve, without allocating power resources in certain embodiments to control a flow of water through the desuperheater.