System and method for de-icing a rotary exchanger

Abstract

A rotary exchanger system includes a rotor configured to rotate about a rotational axis. The rotor is configured to receive a first air flow in a first section of the rotary exchanger system and a second air flow in a second section of the rotary exchanger system, rotation of the rotor moves a segment of the rotor alternately between the first section and the second section of the rotary exchanger system, and a first temperature of the first air flow is greater than a second temperature of the second air flow. The rotary exchanger system also includes a control system configured to operate a damper to block exposure of a segment of the rotor to the second air flow along a path of travel through the second section to inhibit further temperature reduction of the segment of the rotor in the second section.

Description

SYSTEM AND METHOD FOR DE-ICING A ROTARY EXCHANGERCROSS-REFERENCE

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 584,258, entitled “SYSTEM AND METHOD FOR DE-ICING A ROTARY EXCHANGER,” filed September 21, 2023, and hereby incorporated by reference in its entirety for all purposes.TECHNICAL FIELD

[0002] The present disclosure relates to the field of rotary exchangers and, in particular, to de-icing a rotary exchanger.BACKGROUND

[0003] Rotary exchangers or rotary machines are used to condition air. A rotary exchanger includes a rotor through and / or across which different air flows, such as a warm air flow and a cold air flow, are directed. In some embodiments, the rotor may place the warm air flow and the cold air flow in a heat exchange relationship to enable heat transfer between the warm air flow and the cold air flow, such as to heat the cold air flow to a desirable temperature. Unfortunately, the rotor may be susceptible to icing. For example, exposure of the rotor to the cold air flow may cause a portion of the rotor to freeze. Freezing of the rotor may reduce or limit operation of the rotor.SUMMARY

[0004] The present disclosure relates to de-icing a rotary exchanger. For example, according to an embodiment, the present disclosure may be drawn to a rotary exchanger system that includes a rotor configured to rotate about a rotational axis. The rotor is configured to receive a first air flow in a first section of the rotary exchanger system and a second air flow in a second section of the rotary exchanger system, rotation of the rotor moves a segment of therotor alternately between the first section and the second section of the rotary exchanger system, and a first temperature of the first air flow is greater than a second temperature of the second air flow. The rotary exchanger system also includes a control system configured to operate a damper to block exposure of a segment of the rotor to the second air flow along a path of travel through the second section to inhibit further temperature reduction of the segment of the rotor in the second section.

[0005] According to another embodiment, the present disclosure may be drawn to a non- transitory computer-readable medium with instructions that, when executed by one or more processors, are configured to cause the one or more processors to perform operations that include monitoring a temperature of a rotor configured to receive a first air flow and a second air flow, the rotor being configured to rotate about a rotational axis so that a portion of the rotor alternatively receives the first air flow and the second air flow, determining a temperature of the portion of the rotor is below a threshold temperature, and operating a damper to reduce the second air flow entering the portion of the rotor in response to determining the temperature of the portion of the rotor is below the threshold temperature.

[0006] According to yet another embodiment, the present disclosure may be drawn to a rotary exchanger system that includes a rotor configured to receive a first air flow and a second air flow, the rotor being configured to rotate about a rotational axis so that a portion of the rotor is alternately exposed to the first air flow and the second air flow, as well as a damper that is in radial overlap with a first segment of the rotor and is radially offset from a second segment of the rotor such that a closed position of the damper reduces the second air flow onto the first segment of the rotor without reducing the second air flow onto the second segment of the rotor.

[0007] These and other advantages and features will become evident in view of the drawings and detailed description.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] To complete the description and in order to provide for a better understanding of the present disclosure, a set of drawings is provided, wherein like reference numerals refer to like features throughout. The drawings form an integral part of the description and illustrate an embodiment of the present disclosure, which should not be interpreted as restricting the scope of the disclosure, but just as an example of how the disclosure can be carried out. The drawings comprise the following figures:

[0009] FIG. 1 is a schematic view of a system with a rotary exchanger system, in accordance with an example embodiment of the present application;

[0010] FIG. 2 is a partially cut-away perspective view of a rotary heat exchanger, in accordance with an example embodiment of the present application;

[0011] FIG. 3 is a perspective top view of a rotary exchanger system, in accordance with an example embodiment of the present application.

[0012] FIG. 4 is a perspective top view of a rotary exchanger system, in accordance with an example embodiment of the present application.

[0013] FIG. 5 is a perspective top view of a rotary exchanger system, in accordance with an example embodiment of the present application.

[0014] FIG. 6 is a schematic top view of a rotary exchanger system, in accordance with an example embodiment of the present application.

[0015] FIG. 7 is a side view of a rotary exchanger system, in accordance with an example embodiment of the present application.

[0016] FIG. 8 is a side view of a rotary exchanger system, in accordance with an example embodiment of the present application.

[0017] FIG. 9 is a flowchart of a method for de-icing a rotary exchanger system, in accordance with an example embodiment of the present application.

[0018] FIG. 10 is a flowchart of a method for de-icing a rotary exchanger system, in accordance with an example embodiment of the present application.DETAILED DESCRIPTION

[0019] Generally, this disclosure is directed to de-icing a rotary exchanger. As used herein, de-icing refers to removal of ice, prevention / discouragement of ice formation, or any other suitable manner of limiting a temperature decrease. Thus, a rotary exchanger may be de-iced without there being any physical presence of ice on the rotary exchanger.

[0020] The rotary exchanger includes a rotor configured to transfer heat or other particles between air flows. In particular, the rotor rotates to alternate exposure of different portions of the rotor between the various air flows. The change in exposure of the rotor to the different air flows transfers the heat / particles between the air flows. One of the air flows is a relatively warm air flow, and another of the air flows is a relatively cold air flow. The cold air flow may reduce a temperature of the rotor, and a sufficiently low temperature of the rotor can reduce effective operation of the rotary exchanger, such as by reducing efficiency of heat / particle transfer between the air flows and / or by reducing movability of the rotor.

[0021] To inhibit the temperature reduction caused by the cold air flow, the rotor’s exposure to the cold air flow is selectively reduced. For example, a damper may block flow of the cold air flow onto a portion of the rotor while the portion of the rotor is disposed in a cold air flow region of the exchanger. However, warm air flow may still be able to flow onto the portion of the rotor to heat the portion of the rotor (e.g., after rotation of the portion through the cold air flow region). Accordingly, operation of the damper may increase a temperature of the rotor or at least limit a temperature decrease of the rotor below a threshold temperature. As a result, desirable operation of the rotary exchanger is maintained.

[0022] An example power plant 10 of a type that may incorporate a rotary heat exchanger 12 with heat transfer elements according to the present invention is illustrated in Fig. 1. Thepower plant 10 includes a generator 14 coupled with a steam turbine 16 to produce electricity. The turbine 16 is driven by steam from a boiler 18, which receives air for combustion via an air intake 20 and expels combustion gases via an exhaust 22. Fans 24a and 24b may be used to supply air to the boiler intake 20 and to draw combustion gases from the exhaust 22 through a dust removal system 26 before it is released to the atmosphere. A rotary regenerative heat exchanger 12 may be positioned adjacent the air intake 20 and the exhaust 22 to preheat air entering the boiler 18 using heat from combustion gases expelled from the boiler. Rotary regenerative heat exchangers may also be used in gas-gas heaters to control emissions from the plant. Another implementation of the rotary regenerative heat exchanger 12 may include a mining operation to preheat very cold air (e.g., ambient air) entering a mine by using the heat available in the warmer exhaust air from the mine. A further implementation of the rotary regenerative heat exchanger 12 may include usage in a cold environment in which the rotary regenerative heat exchanger 12 is constantly exposed to surrounding cold ambient air (e.g., at sub-zero temperatures).

[0023] Referring now to Fig. 2, a partially cut-away perspective view of a rotary heat exchanger 12 utilizing heat transfer elements and containers according to an example embodiment of the present invention is shown. The rotary heat exchanger 12 includes a housing 28 with a first duct or opening 30 and a second duct or opening 32. The first opening 30 communicates with the boiler air intake 20 and the second opening 32 communicates with the boiler exhaust 22. A rotor 34 containing a plurality of heat transfer element containers 36 is mounted for rotation in the housing 28 such that the heat transfer element containers 36 in the rotor circulate past the openings 30 and 32, thus causing heat transfer elements in the heat transfer element containers 36 to be heated by exhaust gases when aligned with the second opening 32 and preheating incoming air when aligned with the first opening 30.

[0024] FIG. 3 is a perspective top view of a rotary exchanger system 100. The rotary exchanger system 100 includes a rotor 102 configured to rotate about a rotational axis 104. The rotary exchanger system 100 also includes a conduit system 106 (e.g., ductwork) configured to direct different air flows onto the rotor 102. For example, a first conduit 108 of the conduit system 106 is configured to direct a warm air flow 110 therethrough, and second conduits 112 of the conduit system are configured to direct cold air flows 114 therethrough (e.g., to separate locations for different usages). However, in other embodiments, a rotary exchanger system may include any quantity of conduits that allow any quantity of flows onto different areas (e.g., radial areas) above and below the rotor. That is, any suitable quantity of warm air flows and cold air flows may be utilized. For instance, the conduit system 106 may direct a single cold air flow and / or multiple warm air flows. Additionally, even though the illustrated rotary exchanger system 100 includes the warm air flow 110 flowing in a different (e.g., opposite) direction as the directions in which the cold air flow 114 is flowing through the rotor 102, in some embodiments, warm air and cold air flow in the same direction through the rotor 102.

[0025] The rotor 102 is exposed to each of the warm air flow 110 and the cold air flows 114. As an example, the conduit system 106 defines a housing 116 in which the rotor 102 is positioned. As used herein, a warm air flow 110 includes an air flow that is at a relatively higher temperature than the cold air flow(s) 114 prior to contacting the rotor 102, and a cold air flow 114 includes an air flow that is at a relatively lower temperature than the warm air flow 110 prior to contacting the rotor 102. At a particular instance, a first portion of the rotor 102 is aligned with the first conduit 108, and a second portion of the rotor 102 is aligned with one of the second conduits 112. Rotation of the rotor 102 about the rotational axis 104 changes the position of the portions of the rotor 102. For example, rotation of the rotor 102 for a duration of time after the particular instance may move at least some of the first portion of the rotor 102into one of the second conduits 112 and move at least some of the second portion of the rotor 102 into the first conduit 108. In this manner, the position of any particular portion of the rotor 102 may continually change or alternate between the first conduit 108 and the second conduits 112 during operation of the rotary exchanger system 100, thereby alternately receiving or being exposed to the warm air flow 110 and the cold air flow(s) 114.

[0026] Rotating the rotor 102 conditions the cold air flow(s) 114 via the warm air flow 110 or vice versa. For instance, the rotor 102 may capture (e.g., absorb) heat (e.g., a heat particle) from the warm air flow 110 and discharge the heat to the cold air flow(s) 114, thereby placing the warm air flow 110 and the cold air flow(s) 114 in a heat exchange relationship to heat the cold air flow(s) 114. In such embodiments, the rotor 102 operates as a heat exchanger, such as to preheat the cold air flow(s) 114 and / or to precool the warm air flow 110 for further processing or usage. To achieve this, the rotor 102 may comprise heat transfer elements 118. Although the present disclosure primarily focuses on a rotor embodiment that transfers heat between a warm air flow and a cold air flow, it should be noted that the techniques disclosed herein may be applied to other types of rotors. As an example, the techniques may be implemented for a rotor of a machine (e.g., a rotary adsorption machine) configured to transfer a particular molecule (e.g., a chemical particle) between air flows (e.g., air flows at different temperatures) by adsorbing the particular molecule from one air flow and transferring the molecule to another air flow.

[0027] Exposure of the rotor 102 to the cold air flow may reduce the temperature of the rotor 102. Consequently, the rotor 102 may be susceptible to icing caused by reduced temperatures, and icing of the rotor 102 may reduce or limit operation of the rotor 102 (e.g., to effectively or efficiently heat the cold air flows 114, to rotate the rotor 102 about the rotational axis 104). For example, for a rotor 102 used in very cold ambient environments to preheat ambient air, the ambient air may be extremely cold prior to contacting the rotor 102 and maydrastically reduce temperatures of the rotor 102 where the ambient air contacts the rotor 102. Additionally or alternatively, for a rotor 102 used in cryogenic applications, a process air flow used to condition ambient air (e.g., warmer ambient air) may be extremely cold prior to contacting the rotor 102 and may drastically reduce temperatures of the rotor 102 where the process air flow contacts with the rotor 102. In either example, increasing the temperature of the rotor 102 to avoid icing may improve operation of the rotor 102. To this end, exposure of the rotor 102 to the cold air flow(s) 114 may be adjusted to avoid substantial temperature decreases and potential icing of the rotor 102. Reducing exposure of the rotor 102 to the cold air flow(s) 114 may also enable the warm air flow to increase the temperature of the rotor 102, further avoiding icing of the rotor 102.

[0028] FIG. 4 is a perspective top view of a rotary exchanger system 150. The illustrated rotary exchanger system 150 includes a rotor 152 that, at any given time during operation of the rotary exchanger system 150, is exposed to a warm air flow 154 and a cold air flow 156. For example, at a first section 158 of the rotary exchanger system 150, a first conduit 160 is configured to direct the warm air flow 154 onto the rotor 152 (e.g., at a first end / side 162 of the rotor 152), and, at a second section 164 of the rotary exchanger system 150, a second conduit 166 is configured to direct the cold air flow 156 onto the rotor 152 (e.g., at a second end / side 168 of the rotor 152). Rotation of the rotor 152 about a rotational axis 170 moves a portion of the rotor 152 alternately between the first section 158 and the second section 164, thereby alternating exposure of the portion to the warm air flow 154 and to the cold air flow 156. For example, initial exposure of the portion of the rotor 152 to the warm air flow 154 may transfer heat from the warm air flow 154 to the portion, and subsequent exposure of the portion to the cold air flow 156 may transfer heat from the portion to the cold air flow 156, thereby heating the cold air flow 156.

[0029] The rotary exchanger system 150 also includes a damper 172 disposed in the second section 164, such as within the second conduit 166. The damper 172 is configured to open and close to control flow of the cold air flow 156 onto the rotor 102. The damper 172 extends concentrically about the rotational axis 170 and is therefore concentrically aligned with the rotor 152. For example, the damper 172 may have an arcuate or annular shape with an inner diameter and an outer diameter. Thus, the damper 172 is radially offset from an inner annular segment 174 and an outer annular segment 176 of the rotor 152 while radially overlapping with an intermediate annular segment 178 of the rotor 152. In some embodiments, the damper 172 has a flap 180 with a more rectangular shape farther away from the rotor 152 (e.g., at a transition duct termination flange 182 of the second conduit 166), and the damper 172 transitions to the arcuate shape toward the rotor 152. That is, the damper transitions from a rectangular shape to an arcuate shape along its extension toward the rotor 152. Such an arrangement of the damper may facilitate implementation within the rotary exchanger system 150, such as coupling to and / or fitting within the second conduit 166. However, in additional or alternative embodiments, the flap 180 may have any suitable shape, such as substantially the same arcuate shape as that near the rotor 152 (e.g., the damper is homogenously or uniformly arcuate along the second conduit 166).

[0030] Rotation of the rotor 152 may drive a portion of the intermediate annular segment 178 of the rotor 152 about a path of travel 184 extending around the rotational axis 170, through the first section 158, and through the second section 164. The damper 172 overlaps with the path of travel 184 throughout the second section 164 and therefore controls exposure of the intermediate annular segment 178 to the cold air flow 156. In an open position 186 of the damper 172, the damper 172 enables flow of the cold air flow 156 therethrough. To this end, the flap 180 extends substantially along (e.g., parallel to) a direction of travel 188 of the cold air flow 156 through the second conduit 166 and onto the rotor 152. Thus, the open position186 of the damper 172 exposes the intermediate annular segment 178 to the cold air flow 156 in the second section 164. However, in a closed position (not shown in FIG. 3) of the damper 172, the damper 172 blocks or reduces flow of the cold air flow 156 therethrough. As an example, the flap 180 may be moved (e.g., rotated) to extend transverse to the direction of travel 188 of the cold air flow 156, thereby blocking flow of the cold air flow 156 toward the intermediate annular segment 178. Consequently, the closed position of the damper 172 blocks, eliminates, or reduces exposure of the intermediate annular segment 178 to the cold air flow 156. As a result, cooling of the intermediate annular segment 178 may be reduced while the damper 172 is in the closed position.

[0031] However, because the damper 172 is offset from the path of travel 184 in the first section 158, the closed position of the damper 172 does not affect exposure of the intermediate annular segment 178 to the warm air flow 154 (which may also enter from an opposite side of the rotor 152 as compared to the cold air flow 156). Consequently, the warm air flow 154 may continue to be directed onto the intermediate annular segment 178 in the first section 158 (e.g., at the path of travel 184 extending through the first section 158). Therefore, the closed position of the damper 172 may help increase the temperature of the intermediate annular segment 178 by blocking flow of the cold air flow 156 onto the intermediate annular segment 178, while still enabling flow of the warm air flow 154 onto the intermediate annular segment 178. Additionally, because the damper 172 is radially offset from respective paths of travels of the inner annular segment 174 and the outer annular segment 176 of the rotor 152, the closed position of the damper 172 does not reduce flow of the cold air flow 156 onto the inner annular segment 174 or the outer annular segment 176. In other words, the inner annular segment 174 and the outer annular segment 176 of the rotor 152 remain exposed to the cold air flow 156 while the damper 172 is in the closed position.

[0032] In some embodiments, the rotary exchanger system 150 may include multiple dampers 172, 190, 192 each configured to control flow of the cold air flow 156 onto a corresponding annular segment (e.g., the inner annular segment 174, the outer annular segment 176) of the rotor 152 at the second section 162. To this end, each damper 172, 190, 192 overlaps with a respective path of travel of the annular segments 174, 176, 178 throughout the second section 164 and may block or eliminate exposure of a corresponding portion of the rotor 152 along its respective path of travel. That is, the dampers 172, 190, 192 establish annular subdivisions within the second conduit 166. For example, each damper 172, 190, 192 may have an arcuate shape adjacent to the rotor 152 (e.g., at a distal or downstream portion of the second conduit) and a rectangularly shaped flap 180 farther away from the rotor 152 (e.g., at a proximal or upstream portion of the second conduit 166).

[0033] The dampers 172, 190, 192 may be selectively closed to adjust exposure of different annular segments 174, 176, 178 of the rotor 152 to the cold air flow 156 in the second section 164 and therefore to adjust the volume through which the cold air flow 156 may be directed. In this manner, the usage of multiple dampers 172, 190, 192 may provide increased (e.g., granular) temperature control for the annular segments 174, 176, 178 of the rotor 152, such as to selectively increase a temperature of different annular segments at different times of operation of the rotary exchanger system 150. Indeed, because blocking cold air flow 156 onto a portion (e.g., one of the annular segments 174, 176, 178) of the rotor 152 may reduce heat transfer provided by the portion of the rotor 152, it may be desirable to limit blockage of cold air flow 156 onto the rotor 152 while maintaining a sufficiently high temperature of the rotor 152. For this reason, the implementation and control of multiple dampers 172, 190, 192 provide greater acute control over directing the cold air flow 156 onto the rotor 152 to balance between providing sufficient heat transfer and avoiding an undesirable temperature reduction of the rotor 152. In such embodiments, the surface area of each damper 172, 190, 192configured to block or eliminate exposure of the rotor 152 may be approximately equal to one another. In other words, each damper 172, 190, 192 may block approximately the same amount (e.g., a corresponding surface area) of the rotor 152.

[0034] FIG. 5 is a perspective top view of the rotary exchanger system 150. In particular, FIG. 5 illustrates the damper 172 in a closed position 250, which may be effectuated by moving (e.g., rotating) the flap 180 of the damper 172. In the closed position 250, the flap 180 of the damper 172 extends transverse (e.g., perpendicular) to the direction of travel 188 of the cold air flow 156. For example, the flap 180 of the damper 172 may extend toward and into contact with the flap 180 of the damper 192. Consequently, the flap 180 of the damper 172 overlaps with the intermediate annular segment 178 (not shown in FIG. 5) to block flow of the cold air flow 156 onto the intermediate annular segment 178.

[0035] The dampers 190, 192 remain in the open position 186 in the illustrated configuration of the rotary exchanger system 150. For instance, the respective flaps 180 of the dampers 190, 192 may extend substantially along the direction of travel 188, thereby enabling the cold air flow 156 to be directed onto the inner annular segment 174 and the outer annular segment 176. However, closure of the flaps 180 of the dampers 190, 192 (e.g., such that the flaps 180 extend transverse to the direction of travel 188) also blocks flow of the cold air flow 156 onto the inner annular segment 174 and the outer annular segment 176.

[0036] The depicted rotary exchanger system 150 includes a control system 252 (e.g., a programmable controller, an electronic controller, a cloud computing server) configured to operate the dampers 172, 190, 192. The control system 252 includes a memory 254 and a processor 256 (e.g., processing circuitry). The memory 254 includes read only memory (ROM), random access memory (RAM), magnetic disk storage media devices, optical storage media devices, flash memory devices, electrical, optical, or other physical / tangible (e.g., non- transitory) memory storage devices. Thus, in general, the memory 254 includes one or morecomputer-readable storage media (e.g., a memory device) encoded with software with computer executable instructions that may be executed to effectuate the operations described herein. For example, the memory 254 stores or is encoded with instructions for adjusting the dampers 172, 190, 192.

[0037] The processor 256 includes a collection of microcontrollers and / or microprocessors, for example, each configured to execute respective software instructions stored in the memory 254. The processor 256 is configured to, for example, execute the instructions stored in the memory 254 to adjust the dampers 172, 190, 192 (e.g., sequentially, iteratively, or alternately open and close a series of dampers). To this end, the processor 256 is communicatively coupled to actuators 258 configured to adjust the dampers 172, 190, 192 between the open position and the closed position. As an example, the processor 256 is configured to transmit a signal to one of the actuators 258 to move a flap 180 to transition a corresponding one of the dampers 172, 190, 192 to the closed position.

[0038] In certain embodiments, the control system 252 is configured to adjust any of the dampers 172, 190, 192 at prescheduled time intervals. For example, the control system 252 is configured to adjust the dampers 172, 190, 192 between the closed position 250 and the open position 186 at a particular frequency, such as after a threshold duration of time has passed. Such operation of the dampers 172, 190, 192 may sufficiently block prolonged exposure of the annular segments 174, 176, 178 of the rotor 152 to the cold air flow 156 to avoid temperature decreases that would cause icing of the rotor 152. In additional or alternative embodiments, the control system 252 is configured to monitor the temperature of the rotor 152 (e.g., by directly monitoring the temperature or by monitoring a parameter, such as pressure, related to temperature) and adjust the dampers 172, 190, 192 based on the monitored temperature.

[0039] By way of example, the rotary exchanger system 150 may include one or more sensors 260 configured to detect the temperature of the annular segments 174, 176, 178 of therotor 152. In such embodiments, the control system 252 may be communicatively coupled to the sensor(s) 260 and configured to compare the determined temperature of the annular segments 174, 176, 178 of the rotor 152 with a threshold temperature (e.g., a relatively lower threshold temperature). In response to determining the temperature of one of the annular segments 174, 176, 178 of the rotor 152 is less than the threshold temperature, the control system 252 is configured to transition a corresponding damper 172, 190, 192 to the closed position 250 by communicating with an associated actuator 258, thereby facilitating heating of that annular segment 174, 176, 178 of the rotor 152. The control system 252 may continue to monitor the temperature of the annular segment 174, 176, 178 of the rotor 152 and maintain the closed position 250 of the damper 172, 190, 192 until a determination is made that the temperature of the annular segment 174, 176, 178 of the rotor 152 is sufficiently high (e.g., above a relatively higher threshold temperature). Upon determining the temperature of the annular segment 174, 176, 178 of the rotor 152 is sufficiently high, the control system 252 may transition the damper 172, 190, 192 to the open position 186 to increase flow of the cold air flow 156 onto the annular segment 174, 176, 178 of the rotor 152. Alternatively, the control system 252 may be configured to transition a corresponding damper 172, 190, 192 to the closed position 250 for a predetermined amount of time after determining the temperature of one of the annular segments 174, 176, 178 of the rotor 152 is less than the threshold temperature.

[0040] In any case, the parameter determined by the sensor(s) 260 may indicate a pressure differential between one of the annular segments 174, 176, 178 (e.g., the intermediate annular segment 178) of the rotor 152 and another annular segment 174, 176, 178 (e.g., the inner annular segment 174, the outer annular segment 176) of the rotor 152. The pressure differential may also indicate the temperature of the annular segment 174, 176, 178 (e.g., relative to the temperature of the other annular segment 174, 176, 178, which may be at a desirable temperature). The control system 252 may close a damper 172, 190, 192 in response to thepressure differential being above a threshold pressure (e.g., indicative of the temperature of the annular segment 174, 176, 178 being above a desirable temperature) to heat the annular segment 174, 176, 178, and / or the control system 252 may open the damper 172, 190, 192 in response to the pressure differential being below another threshold pressure (e.g., indicative of the temperature of the annular segment 174, 176, 178 being sufficiently high) to enable cold air flow 156 onto the annular segment 174, 176, 178.

[0041] It should be noted that in further embodiments, the control system 252 may be configured to move one of the dampers 172, 190, 192 to an intermediate position between the open position 186 and the closed position 250, such as to enable reduced flow of the cold air flow 156 onto the annular segment 174, 176, 178 of the rotor 152. By way of example, the control system 252 may transition the damper 172 to the intermediate position to adjust the temperature change (e.g., temperature increase) of the intermediate annular segment 178 of the rotor 152. This may enable some flow of the cold air flow 156 onto the intermediate annular segment 178 of the rotor 152 to enable some heat transfer via the intermediate annular segment 178, while limiting the temperature decrease of the intermediate annular segment 178, e.g., based on the temperature not being sufficiently low to demand for complete blockage of cold air flow 156 onto the intermediate annular segment 178. This may provide more granular control of the dampers 172, 190, 192.

[0042] Indeed, the control system 252 may be configured to control the dampers 172, 190, 192 independently from one another based on the detections from the sensor 260. As an example, the control system 252 may monitor the temperatures of each annular segment 174, 176, 178 of the rotor 152 and may transition a corresponding one of the dampers 172, 190, 192 to the closed position 250 based on the temperature of the annular segment 174, 176, 178 of the rotor 152 that overlaps with that damper 172, 190, 192 being below a threshold temperature. However, the control system 252 may maintain another of the dampers 172, 190, 192 in theopen position 186 based on the temperature of the annular segment 174, 176, 178 of the rotor 152 that overlaps with that damper 172, 190, 192 being above a threshold temperature. Therefore, the control system 252 may selectively adjust the dampers 172, 190, 192 based on the respective temperatures of different annular segments 174, 176, 178 of the rotor 152 to provide increased temperature control of the annular segments 174, 176, 178. The control system 252 may also consider an overall amount of air flow through the second section 164, perhaps limiting the number of dampers 172, 190, 192 that may be closed at any given time to maintain sufficient air flow through the second section 164 regardless of the temperature of the annular segments 174, 176, 178.

[0043] Further still, in embodiments in which the rotor 152 receives multiple separate cold flows 156 and / or multiple separate warm air flows 154, the control system 252 may be configured to operate separate dampers to control blockage of the respective cold air flows 156 and / or the respective warm air flows 154 directed onto the rotor 152. By way of example, the control system 252 may transition one of the dampers to the closed position 250 to block exposure of the intermediate annular segment 178 of the rotor 152 to a first cold air flow, but the control system 252 may maintain another of the dampers in the open position 186 to maintain exposure of the same intermediate annular segment 178 of the rotor 152 to a second cold air flow.

[0044] FIG. 6 is a top view of the rotary exchanger system 150 in which the intermediate annular segment 178 is blocked from exposure to the cold air flow 156. That is, the damper 172 is in the closed position 250. Accordingly, the damper 172 (e.g., the flap 180) aligns and overlaps with the intermediate annular segment 178 along its path of travel 184 in the second section 164.

[0045] The rotary exchanger system 150 also includes sector plates 300 positioned to shrink the cross-sectional area of the first section 158 as compared to the cross-sectional areaof the second section 164. In particular, the sector plates 300 are arranged to reduce a pressure differential between the first section 158 and the second section 164. For example, closing the damper 172 to reduce exposure of the rotor 152 to the cold air flow increases a pressure at the second section 164 by reducing a volume through which the cold air flow 156 may be directed through the second section 164. The sector plates 300 may correspondingly reduce a volume through which the warm air flow 154 may be directed through the first section 158, thereby correspondingly increasing a pressure in the first section 158. The corresponding increases in pressure at each section 158, 164 caused by the damper 172 and by the sector plates 300 therefore reduce the pressure differential between the sections 158, 164 that may otherwise cause air to flow undesirably between the sections 158, 164 (e.g., flow of the cold air flow 156 from the second section 164 of a relatively higher pressure to the first section 158 of a relatively lower pressure) to affect operation of the rotary exchanger system 150. Indeed, the sector plates 300 may be arranged (e.g., positioned, oriented, sized) such that the volume through which the warm air flow 154 is directed corresponds to the volume through which the cold air flow 156 is directed.

[0046] Each of the illustrated sector plates 300 extends in overlap with a geometric sector of the rotor 152. In this manner, positioning of the sector plates 300 to increase the pressure at the first section 158 (e.g., in response to closing of the damper 172) still exposes a portion of the path of travel in the first section 158 to the warm air flow. Thus, flow of the warm air flow 154 onto each annular segment 174, 176, 178 of the rotor 152 is still enabled.

[0047] In some embodiments, the position of each sector plate 300 is fixed. That is, the sector plates 300 may not be adjustable to change the volume through which the warm air flow 154 may be directed and therefore will not change the pressure at the first section 158. As such, the volume through which the warm air flow 154 may be directed may be constant. Thus, to adjust the volume through which the warm air flow 154 is directed, the sector plates 300may be replaced / removed and / or an additional sector plate may be implemented. In such embodiments, to maintain a substantially similar pressure between the sections 158, 164 (e.g., by maintaining corresponding volumes of the sections 158, 164 through which the warm air flow 154 and the cold air flow 156 may be directed, respectively), one of the annular segments 174, 176, 178 may be blocked from exposure to the cold air flow 156 at any given time. For example, a different damper 172, 190, 192 may be selected and adjusted to its closed position 250 at a different time of operation of the rotary exchanger system 150, while the remaining dampers 172, 190, 192 remain in the open position 186. The closure of one of the dampers 172, 190, 192 may increase the pressure in the second section 164 toward the pressure of the first section 158 effectuated by the sector plates 300. Indeed, the pressure at the second section 164 may be maintained near the pressure at the first section 158 by continually closing a different one of the dampers 172, 190, 192 and opening the remaining dampers 172, 190, 192, thereby reducing the pressure differential between the first section 158 and the second section 164.

[0048] For example, the dampers 172, 190, 192 may be sequentially / altemately closed and opened to change the annular segments 174, 176, 178 that are exposed to the cold air flow 156, thereby limiting a temperature decrease in each ofthe annular segments 174, 176, 178. In other words, by way of example, the damper 172 may initially be closed to block exposure of the intermediate annular segment 178 to the cold air flow 156 during a first period of time, the damper 172 may be open and the damper 190 may be closed to block exposure of the annular segment 174 to the cold air flow 156 during a second period of time after the first period of time, and the damper 190 may be open and the damper 192 may be closed to block exposure of the annular segment 176 to the cold air flow 156 during a third period of time after the second period of time. Such a scheme may avoid exposing annular segments 174, 176, 178 tothe cold air flow 156 for prolonged amounts of time, which, in turn, limits a temperature decrease of each annular segment 174, 176, 178.

[0049] In additional or alternative embodiments, the sector plates 300 are movable, foldable, or otherwise adjustable to change the volume through which the warm air flow 154 may be directed and therefore to change the pressure at the first section 158. For example, the sector plates 300 may be moved (e.g., by a user, such as a technician or operator) based on a change in the damper 172, 190, 192 (e.g., replacement of the damper) that adjusts the volume through which the cold air flow 156 is directed. In another example, the sector plates 300 may be selectively implemented, removed, and / or adjusted as the dampers 172, 190, 192 are opened and closed.

[0050] For instance, during a first period of time, each of the dampers 172, 190, 192 are maintained in the open position 186 to enable flow of the cold air flow 156 through each of the dampers 172, 190, 192. For this reason, the pressure in the second section 164 is relatively lower, and the sector plates 300 are not implemented to maintain the pressure in the first section 158 to be correspondingly lower and reduce a pressure differential between the sections 158, 164. However, during a second period of time, one of the dampers 172, 190, 192 is closed to block flow of the cold air flow 156 through one of the dampers 172, 190, 192, thereby increasing the pressure in the second section 164. Therefore, the sector plates 300 are implemented to correspondingly increase the pressure in the first section 158 and reduce the pressure differential between the sections 158, 164. During a third period of time, another one of the dampers 172, 190, 192 is closed to block flow of the cold air flow 156 through another one of the dampers 172, 190, 192, thereby further increasing the pressure in the second section 164. Accordingly, the sector plates 300 are adjusted to further increase the pressure in the first section 158 and reduce the pressure differential between the sections 158, 164. In other words, each of the dampers 172, 190, 192 and the sector plates 300 may be adjusted to maintaincorrespondence between the volume through which the warm air flow 154 is directed and the volume through which the cold air flow 156 is directed to limit a pressure differential between the sections 158, 164.

[0051] FIG. 7 is a side view of a rotary exchanger system 350 configured to receive a warm air flow at a first section 352 (at the left of FIG. 7) and a cold air flow at a second section 354 (at the right of FIG. 7) onto a rotor 356. The rotary exchanger system 350 includes an auxiliary conduit system 358 (e.g., a purge system, a seal system) configured to block mixture between the warm air flow and the cold air flow. For example, the auxiliary conduit system 358 includes a conduit 360 configured to direct a sealing air flow 362 onto and across the rotor 356 via an outlet 366. The sealing air flow 362 directed across the rotor 356 may create a pressurized barrier between the first section 352 and the second section 354 to block movement of the warm air flow from the first section 352 to the second section 354 and movement of the cold air flow from the second section 354 to the first section 352. Isolating the warm air flow and the cold air flow from one another may improve operation of the rotary exchanger system 350. As an example, the sealing air flow 362 may block the warm air flow and the cold air flow from being in direct contact with one another, which may otherwise reduce heat transfer between the warm air flow and the cold air flow.

[0052] FIG. 8 is a side view of a rotary exchanger system 400, which includes another auxiliary conduit system 402 (e.g., a scavenge system, a disentrainment system). The auxiliary conduit system 402 includes a conduit 404 (e.g., the same conduit directing the sealing air flow 362 of FIG. 7, a separate conduit from that directing the sealing air flow 362) to remove a particle from a rotor 406 to avoid exposure and absorption of the particle with the warm air flow and / or the cold air flow. As an example, moisture may accumulate and become trapped within the rotor 406 as a result of a temperature change (e.g., cooling of the warm air flow) of the rotor 406. The containment of moisture in the rotor 406 may negatively affect conditioning(e.g., heating) of the cold air flow. For instance, the cold air flow may be exposed to and absorb the moisture. Such entrainment of moisture in the cold air flow may undesirably increase a moisture content of the cold air flow (e.g., and reduce a temperature of the cold air flow to be heated).

[0053] Operation of the auxiliary conduit system 402 removes the particle that may be captured within the rotor 406. For instance, the conduit 404 directs a disentrainment air flow 408 through the rotor 406, and the disentrainment air flow may blow off and remove the particle, such as moisture, from the rotor 406 to avoid mixture with the cold air flow. As such, the disentrainment air flow 408 may improve efficient operation of the rotary exchanger system 400.

[0054] In some embodiments, the sealing air flow 362 and / or the disentrainment air flow 408 includes a portion of cold air flow that has been heated by operation of the respective rotary exchanger systems 350, 400. For example, a portion of the cold air flow directed through the rotor 356, 406 may be diverted to flow into the auxiliary conduit system 358, 402. In this manner, mixture of the sealing air flow 362 and / or of the disentrainment air flow 408 with the warm air flow and / or with the cold air flow (e.g., as a result of contact between the sealing air flow 362 and / or the disentrainment air flow 408 with the warm air flow and / or with the cold air flow) may not significantly reduce operation of the rotary exchanger system 350, 400 to heat the cold air flow. For instance, mixture between the heated cold air flow and the warm air flow may not significantly reduce a temperature of the warm air flow (e.g., and therefore avoid significantly reducing a heating capability of the warm air flow), and / or mixture between the heated cold air flow and the cold air flow may help increase a temperature of the cold air flow. In additional or alternative embodiments, a different air flow, such as a portion of the warm air flow (e.g., diverted to flow through the auxiliary conduit system 358, 402 instead of throughthe rotor 356, 406) and / or a neutral air flow that does not include the cold air flow or the warm air flow, may be included in the sealing air flow 362 and / or in the disentrainment air flow 408.

[0055] Each of FIGS . 9 and 10 illustrates a method for operating a rotary exchanger system, such as any of the rotary exchanger systems 100, 150, 350, 400. In some embodiments, each method may be performed by a single entity, such as by the control system. In additional or alternative embodiments, different operations of the methods may be performed by different entities. It should also be noted that the methods may be performed differently than depicted. For example, an additional operation may be performed, a depicted operation may not be performed, and / or depicted operations may be performed differently or in a different order. Furthermore, the respective operations of the methods may be performed in any suitable manner, such as concurrently or sequentially with respect to one another.

[0056] FIG. 9 illustrates a method 450 for operating a rotary exchanger system to increase a temperature of a rotor. At block 452, a damper is operated to reduce a cold air flow (e.g., an ambient air flow) onto a portion of the rotor at a first section of a rotary exchanger system. For example, the damper may be transitioned to a closed position that blocks exposure of the portion of the rotor to the cold air flow. Thus, a temperature reduction of the portion of the rotor, which would otherwise be caused by exposure to the cold air flow, may be inhibited. However, operation of the damper to reduce the cold air flow onto the portion of the rotor may not reduce exposure of the portion of the rotor to a warm air flow. As such, the portion of the rotor may continue to be heated by the warm air flow, thereby increasing the temperature of the rotor and avoiding potential icing of the rotor. In some embodiments, the operation of the damper to reduce the cold air flow onto the portion of the rotor may be performed at a predetermined frequency and / or at predetermined times, such as regardless of a parameter (e.g., temperature) of the rotor.

[0057] At block 454, an additional air flow (e.g., a sealing air flow, a disentrainment air flow) is also directed through or along the rotor (e.g., independently of operation of the damper). In some embodiments, the additional air flow is directed along the rotor between the first section and the second section to provide a seal that blocks undesirable air flow between the first section and the second section. Additionally or alternatively, the additional air flow is directed through the rotor to remove moisture or other particles (e.g., dust) entrained within the rotor. Thus, directing of the additional air flow may improve operation of the rotary exchanger system to transfer heat but need not be utilized with the techniques presented herein to heat the rotor.

[0058] Operation of the rotor itself may also (or alternatively) be adjusted to improve operation of the rotary exchanger system. By way of example, a speed of rotation of the rotor may be adjusted (e.g., reduced) to increase the temperature of the portion of the rotor (e.g., by increasing exposure time to the warm air flow) and / or to increase moisture / particle removal from the rotor (e.g., by increasing exposure time to the additional air flow).

[0059] FIG. 10 is a flowchart of a method 500 for operating a rotary exchanger system to increase a temperature of a rotor. At block 502, a temperature of the rotor is monitored, such as via a sensor. In some embodiments, the temperature is directly monitored. In additional or alternative embodiments, a parameter indicative of the temperature, such as a pressure, is monitored.

[0060] At block 504, a temperature of a portion of the rotor is determined to be below a threshold temperature. Additionally or alternatively, the parameter indicative of the temperature signifies the temperature is low (e.g., a pressure differential between the portion of the rotor and another portion of the rotor is above a threshold pressure). Such a determination may indicate potential icing of the rotor.

[0061] In response, at block 506, a damper is operated to reduce cold air flow directed across the portion of the rotor based on the damper being configured to reduce exposure of the portion of the rotor to the cold air flow. For example, the damper (e.g., a flap of the damper) may be adjusted to overlap with a path of travel of the portion of the rotor throughout a section through which the cold air flow is directed. Such operation of the damper may still enable a warm air flow to be directed onto the portion of the rotor. Thus, the temperature of the portion of the rotor may be increased by maintained exposure to the warm air flow and limited exposure to the cold air flow.

[0062] Operation of the damper to reduce the cold air flow directed onto the portion of the rotor may be maintained for a duration of time. In some embodiments, the duration of time may be predetermined (e.g., regardless of the temperature of the rotor). In additional or alternative embodiments, the duration of time may be based on a determined parameter of the rotor. As an example, the temperature of the rotor may be monitored, and the damper may be opened to increase the cold air flow directed onto the portion of the rotor in response to the temperature of the rotor (e.g., of the portion of the rotor) exceeding a threshold temperature. Additionally or alternatively, a pressure differential between the portion of the rotor and another portion of the rotor may be monitored, and the pressure differential may indicate the temperature of the portion of the rotor (e.g., relative to the temperature of the other portion of the rotor, which may be at a desirable temperature). The damper may be opened to increase the cold air flow directed onto the portion of the rotor in response to the pressure differential being below a threshold pressure. In either case, opening the damper to increase the cold air flow directed onto the portion of the rotor may increase heat transfer effectuated by the portion of the rotor.

[0063] It is also to be understood that the rotor exchanger system described herein, or portions thereof may be fabricated from any suitable material or combination of materials, suchas metals or synthetic materials including, but not limited to, plastic, rubber, derivatives thereof, and combinations thereof. It is also intended that the present disclosure cover the modifications and variations of this disclosure that come within the scope of the appended claims and their equivalents. For example, it is to be understood that terms such as “left,” “right,” “top,” “bottom,” “front,” “rear,” “side,” “height,” “length,” “width,” “upper,” “lower,” “interior,” “exterior,” “inner,” “outer” and the like as may be used herein, merely describe points of reference and do not limit the present disclosure to any particular orientation or configuration. Further, the term “exemplary” is used herein to describe an example or illustration. Any embodiment described herein as exemplary is not to be construed as a preferred or advantageous embodiment, but rather as one example or illustration of a possible embodiment of the disclosure.

[0064] Finally, when used herein, the term “comprises” and its derivations (such as “comprising”, etc.) should not be understood in an excluding sense, that is, these terms should not be interpreted as excluding the possibility that what is described and defined may include further elements, steps, etc. Meanwhile, when used herein, the term “approximately” and terms of its family (such as “approximate”, etc.) should be understood as indicating values very near to those which accompany the aforementioned term. That is to say, a deviation within reasonable limits from an exact value should be accepted, because a skilled person in the art will understand that such a deviation from the values indicated is inevitable due to measurement inaccuracies, etc. The same applies to the terms “about” and “around” and’substantially”.

Claims

CLAIMSWhat is claimed is:

1. A rotary exchanger system, comprising: a rotor configured to rotate about a rotational axis, wherein the rotor is configured to receive a first air flow in a first section of the rotary exchanger system and a second air flow in a second section of the rotary exchanger system, rotation of the rotor moves a segment of the rotor alternately between the first section and the second section of the rotary exchanger system, and a first temperature of the first air flow is greater than a second temperature of the second air flow; and a control system configured to operate a damper to block exposure of a segment of the rotor to the second air flow along a path of travel through the second section to inhibit further temperature reduction of the segment of the rotor in the second section.

2. The rotary exchanger system of claim 1, wherein the control system is configured to: monitor a temperature of the segment of the rotor; determine the temperature of the segment of the rotor is below a threshold temperature; and operate the damper to block exposure of the segment of the rotor to the second air flow along the path of travel through the second section in response to determining the temperature of the segment of the rotor is below the threshold temperature.

3. The rotary exchanger system of claim 2, wherein the segment of the rotor is a part of a plurality of segments of the rotor, the rotary exchanger system comprises a plurality of dampers including the damper, each damper of the plurality of dampers is configured to block exposureof a corresponding segment of the plurality of segments of the rotor to the second air flow along a respective path of travel through the second section, and the control system is configured to operate the plurality of dampers to block exposure of one or more segments of the plurality of segments of the rotor to the second air flow based on the one or more segments of the plurality of segments having the temperature below the threshold temperature.

4. The rotary exchanger system of claim 1, wherein the rotor is configured to absorb heat from the first air flow and to discharge heat to the second air flow to place the first air flow and the second air flow in a heat exchange relationship with one another.

5. The rotary exchanger system of claim 1, wherein the damper overlaps with the path of travel of the segment of the rotor through the second section.

6. The rotary exchanger system of claim 5, wherein the damper radially overlaps with the segment of the rotor in the second section and is radially offset from an additional segment of the rotor through the second section, such that a closed position of the damper does not block exposure of the additional segment of the rotor to the second air flow along an additional path of travel through the second section.

7. The rotary exchanger system of claim 5, wherein the damper is offset from an additional path of travel of the segment of the rotor through the first section such that a closed position of the damper does not block exposure of the segment of the rotor to the first air flow along the additional path of travel through the first section.

8. The rotary exchanger system of claim 1, comprising a conduit system configured to direct a third air flow onto the rotor to block undesirable conditioning of the first air flow and / or of the second air flow.

9. The rotary exchanger system of claim 8, wherein the conduit system is configured to direct the third air flow through the rotor to reduce a moisture content in the rotor.

10. The rotary exchanger system of claim 8, wherein the conduit system is configured to direct the third air flow along the rotor to block mixture between the first air flow and the second air flow.

11. The rotary exchanger system of claim 1, comprising a sector plate positioned to reduce a volume through which the second air flow is directed as compared to a volume through which the first air flow is directed and to reduce a pressure differential between the first section and the second section.

12. A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, are configured to cause the one or more processors to perform operations comprising: monitoring a temperature of a rotor configured to receive a first air flow and a second air flow, wherein the rotor is configured to rotate about a rotational axis so that a portion of the rotor alternatively receives the first air flow and the second air flow; determining a temperature of the portion of the rotor is below a threshold temperature; andoperating a damper to reduce the second air flow entering the portion of the rotor in response to determining the temperature of the portion of the rotor is below the threshold temperature.

13. The non-transitory computer-readable medium of claim 12, wherein the instructions, when executed by the one or more processors, are configured to cause the one or more processors to operate the damper to reduce the second air flow entering the portion of the rotor based on the damper overlapping with a path of travel of the portion of the rotor having the temperature below the threshold temperature.

14. The non-transitory computer-readable medium of claim 12, wherein the instructions, when executed by the one or more processors, are configured to cause the one or more processors to perform operations comprising: determining the temperature of the portion of the rotor is above an additional threshold temperature; and operating the damper to increase the second air flow entering the portion of the rotor in response to determining the temperature of the portion of the rotor is above the additional threshold temperature.

15. The non-transitory computer-readable medium of claim 12, wherein the instructions, when executed by the one or more processors, are configured to cause the one or more processors to determine the temperature of the portion of the rotor is below the threshold temperature based on a pressure differential between the portion of the rotor and an additional portion of the rotor is above a threshold pressure.

16. A rotary exchanger system, comprising: a rotor configured to receive a first air flow and a second air flow, wherein the rotor is configured to rotate about a rotational axis so that a portion of the rotor is alternately exposed to the first air flow and the second air flow; and a damper that is in radial overlap with a first segment of the rotor and is radially offset from a second segment of the rotor such that a closed position of the damper reduces the second air flow onto the first segment of the rotor without reducing the second air flow onto the second segment of the rotor.

17. The rotary exchanger system of claim 16, comprising a section through which the second air flow is directed, wherein rotation of the rotor moves the first segment along a path of travel through the section, and the damper is positioned at the section such that the closed position of the damper reduces or eliminates exposure of the first segment to the second air flow along the path of travel through the section.

18. The rotary exchanger system of claim 16, comprising an additional damper that is in radial overlap with the second segment of the rotor and is radially offset from the first segment of the rotor such that a closed position of the additional damper reduces the second air flow onto the second segment of the rotor without reducing the second air flow onto the first segment of the rotor.

19. The rotary exchanger system of claim 18, comprising a control system configured to operate the damper and the additional damper, wherein the control system is configured to alternately and sequentially adjust the damper and the additional damper into and out of their respective closed positions.

20. The rotary exchanger system of claim 16, wherein the damper comprises a flap, and the flap is configured to move to extend transverse to a direction in which the second air flow is directed to the rotor to reduce the second air flow onto the first segment of the rotor in the closed position of the damper.

Images