Interstage flow control valve for bypass flow distribution and regulation of multistage centrifugal compressors

Abstract

A centrifugal compressor may include a bypass flow of intermediate pressure steam between stages of the compressor. The bypass flow may be controlled by a bypass injection port controlled by a flow control valve having a curved surface facing the refrigerant flow from the first stage to the second stage. The flow control valve may allow or block flow through the bypass injection port. The flow control valve may extend and retract in a direction substantially perpendicular to the direction of flow from the first stage blades to the second stage blades. The bypass injection port and the flow control valve may be annular. The bypass injection port and the flow control valve may allow at least some bypass flow to be introduced on the side of the flow control valve opposite the curved surface.

Description

Technical Field

[0001] The present application relates to an interstage flow control valve for a centrifugal compressor, and in particular to providing bypass flow regulation or distribution. Background Art

[0002] Multistage compressors may use single or multiple rows, fixed or rotatable return vanes to direct and / or control interstage flow when operating at full and part load conditions. These return vanes can cause low momentum regions in the return flow path or change adverse pressure gradients for the intended bypass injection flow under part load conditions, which can cause compressor instability, reduce system efficiency, and result in a narrower operating range. Summary of the invention

[0003] The present application relates to an interstage flow control valve for a centrifugal compressor, and in particular to providing bypass flow regulation or distribution.

[0004] The interstage flow control valve can regulate the bypass flow to increase the interstage flow while controlling the flow between the stages of the multi-stage compressor (i.e., the interstage flow). The interstage flow control valve increases the speed of increasing the interstage flow of the bypass flow and avoids the stagnant area of ​​the flow. This in turn can improve the stability and efficiency of the compressor under partial and full load conditions.

[0005] The axial extension of the interstage flow control valve may further reduce maintenance issues associated with the complexity of the rotatable blade design in the centrifugal compressor.

[0006] In addition, embodiments can increase bypass flow at relatively low pressure regions of the interstage line, facilitating increased bypass flow and allowing more bypass flow to be successfully introduced. This can avoid bypass gas circulation and compression.

[0007] In one embodiment, a centrifugal compressor includes a first-stage blade and a second-stage blade. The centrifugal compressor includes a bypass injection port located between the first-stage blade and the second-stage blade, and the bypass injection port is configured to receive a bypass flow of a fluid. The centrifugal compressor includes a flow control valve. The flow control valve is configured to extend and retract through the bypass injection port. The flow control valve has a curved surface facing the flow direction from the first-stage blade to the second-stage blade. The flow control valve is configured to extend through the bypass injection port between an open position and a closed position, wherein in the open position, the bypass flow of the fluid can flow through the bypass injection port and in the closed position, the flow control valve blocks the flow of the bypass flow of the fluid from flowing through the bypass injection port.

[0008] In one embodiment, the flow control valve has an annular shape.

[0009] In one embodiment, the centrifugal compressor includes a plurality of side stream injection ports and a plurality of flow control valves.

[0010] In one embodiment, when in the open position, the tip of the flow control valve at one end of the curved surface is located within the side stream injection port.

[0011] In one embodiment, the flow control valve extends and retracts in a direction substantially perpendicular to the flow direction from the first stage blades to the second stage blades.

[0012] In one embodiment, the centrifugal compressor further comprises one or more counter-rotating blades between the first stage blades and the second stage blades. In one embodiment, the flow control valve comprises one or more recessed portions, each of the one or more recessed portions being configured to accommodate at least a portion of the one or more counter-rotating blades. In one embodiment, each of the one or more counter-rotating blades comprises one or more recessed portions, each of the one or more recessed portions being configured to accommodate at least a portion of the flow control valve.

[0013] In one embodiment, the flow control valve has a linear meridional profile on the opposite side of the curved surface, the linear meridional profile contacting an edge of the side stream injection port.

[0014] In one embodiment, the side of the flow control valve opposite the curved surface is configured such that when the flow control valve is between an open position and a closed position, fluid can flow through the flow control valve on the side of the flow control valve opposite the curved surface. In one embodiment, the side of the flow control valve opposite the curved surface includes a second curved surface. In one embodiment, the side of the flow control valve opposite the curved surface includes one or more flow channels, and the one or more flow channels are configured to allow a flow rate of bypass flow of the fluid.

[0015] In one embodiment, a heating, ventilation, air conditioning and refrigeration (HVACR) circuit includes a centrifugal compressor, a condenser, an expander and an evaporator. The centrifugal compressor includes a first stage blade and a second stage blade. The centrifugal compressor also includes a bypass injection port located between the first stage blade and the second stage blade. The bypass injection port is configured to receive a bypass flow of a fluid. The centrifugal compressor also includes a flow control valve. The flow control valve is configured to extend and retract through the bypass injection port. The flow control valve has a curved surface facing the flow direction from the first stage blade to the second stage blade. The flow control valve is configured to extend through the bypass injection port between an open position and a closed position, wherein in the open position, the bypass flow of the fluid can flow through the bypass injection port and in the closed position, the flow control valve blocks the flow of the bypass flow of the fluid from flowing through the bypass injection port.

[0016] In one embodiment, the side flow of the fluid is from a condenser to the side flow injection port.

[0017] In one embodiment, the HVACR circuit further comprises an economizer, and wherein the bypass flow of the fluid is from the economizer to the bypass flow injection port.

[0018] In one embodiment, the HVACR circuit further comprises an intercooler, and wherein the bypass flow of the fluid is from the intercooler to the bypass flow injection port.

[0019] In one embodiment, the flow control valve has an annular shape.

[0020] In one embodiment, the flow control valve has a linear meridian profile on the side opposite the curved surface, and the meridian profile contacts the linear meridian profile of the bypass injection port. In one embodiment, the side of the flow control valve opposite the curved surface is configured so that when the flow control valve is between an open position and a closed position, fluid can flow through the flow control valve on the side of the flow control valve opposite the curved surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1A A cross-sectional view of a compressor is shown when the flow control valve is in a fully open position according to one embodiment.

[0022] Figure 1B shows that when the flow control valve is in the high flow position, Figure 1A A cross-sectional view of the compressor is shown in FIG.

[0023] Figure 1c shows that when the flow control valve is in the low flow position, Figure 1A A cross-sectional view of the compressor is shown in FIG.

[0024] Figure 1D shows that when the flow control valve is in the closed position, Figure 1A A cross-sectional view of the compressor is shown in FIG.

[0025] Figure 2A A cross-sectional view of a compressor is shown when the flow control valve is in a fully open position according to one embodiment.

[0026] Figure 2B shows that when the flow control valve is in the high flow position, Figure 2A A cross-sectional view of the compressor is shown in FIG.

[0027] Figure 2C shows that when the flow control valve is in the low flow position, Figure 2A A cross-sectional view of the compressor is shown.

[0028] Figure 2Dshows that when the flow control valve is in the closed position, Figure 2A A cross-sectional view of the compressor is shown in FIG.

[0029] Figure 3A A heating, ventilation, air conditioning, and refrigeration (HVACR) circuit is shown according to one embodiment.

[0030] Figure 3B An energy-efficient HVACR loop 320 is shown according to one embodiment.

[0031] Figure 4 A cross-sectional view of a centrifugal compressor along an interstage flow path is shown according to one embodiment.

[0032] Figure 5 A cross-sectional view of a portion of a centrifugal compressor is shown according to one embodiment. DETAILED DESCRIPTION

[0033] The present application relates to an interstage flow control valve for a centrifugal compressor, and in particular to providing bypass flow regulation or distribution.

[0034] Figure 1A FIG. 2 shows a cross-sectional view of the compressor 100 when the flow control valve is in a fully open position according to one embodiment. The compressor 100 may have a cylindrical structure such that Figures 1A to 1D The cross-sectional views shown in are repeated or continuously rotated 360° around the axis of the compressor 100 .

[0035] The compressor 100 is a multi-stage centrifugal compressor according to one embodiment. The compressor 100 includes an inlet guide vane 102, in which a core flow of a fluid to be compressed is received. The compressor 100 includes a first-stage blade 104 driven by the rotation of a shaft 106, a diffuser 108 downstream of the first-stage blade 104, and a return bend 110 downstream of the diffuser 108. The compressor 100 also includes one or more reverse rotation blades 112 downstream of the return bend 110. The compressor 100 includes a bypass injection port 114 and a flow control valve 116. The compressor 100 includes a reverse rotation blade 112 and a second-stage blade 118 downstream of the bypass injection port 114, as well as a vortex volute 120 and a discharge cone 122 downstream of the second-stage blade 118.

[0036] Although the compressor 100 is Figures 1A to 1D 1 is shown as a two-stage compressor, but the compressor according to the embodiment may include any number of stages, and a bypass flow injection port 114 and a flow control valve 116 disposed in the flow path between any two stages of the compressor. For example, the compressor 100 may be a three-stage compressor, and a bypass flow injection port 114 and a flow control valve 116 disposed between the outlet of the second stage and the inlet of the third stage, and so on.

[0037] One or more inlet guide vanes 102 may be used to control the flow of the working fluid into the compressor 100. The one or more inlet guide vanes 102 may be configured to obstruct or allow the working fluid to flow into the compressor 100. In one embodiment, each inlet guide vane 102 may be a rotating vane, for example, each rotating vane forms a circular cross-section, so that when all rotating vanes are in a closed position, the inlet guide vane 102 obstructs the inlet of the compressor 100. The one or more inlet guide vanes 102 may be movable between a fully open position and a closed position. In the fully open position, the effect of the inlet guide vane 102 on the flow of the compressor 100 may be minimized, for example, by positioning the inlet guide vane 102 so that the plane of each vane is substantially parallel to the flow direction of the working fluid at the inlet of the compressor 100. In one embodiment, the one or more inlet guide vanes 102 may each be continuously changed from a fully open position to a closed position through one or more partially open positions.

[0038] The compressor 100 includes a first stage blade 104. The first stage blade 104 includes a plurality of blades. The first stage blade 104 is configured to draw in the working fluid flowing through the one or more inlet guide vanes 102 when rotating, and discharge the working fluid toward the diffuser 108. The first stage blade 104 is connected to a shaft 106. The shaft 106 is rotated by a main motive force such as an electric motor, for example.

[0039] The diffuser 108 receives the fluid discharged from the first stage blades 104 and guides the fluid toward the return bend 110. The return bend 110 changes the direction of the fluid flow so that it (the return bend 110) passes through the reverse rotation blades 112 toward the second stage blades 118.

[0040] One or more anti-rotation blades 112 are blades extending from the return bend 110 toward the second-stage blades 118. When the flow flows toward the second-stage blades 118, the flow is shaped to draw the fluid along the anti-rotation blades 112. The anti-rotation blades 112 may include a recessed portion configured to receive at least a portion of the flow control valve 116.

[0041] The bypass injection port 114 is a port configured to allow a bypass flow to be introduced into the interstage flow of the fluid through the compressor 100. The bypass injection port 114 includes a front end 124 and a rear end 126, the front end 124 facing the return bend 110 and the rear end 126 facing the second stage blade 118. The bypass injection port 114 fluidly connects the bypass flow channel 128 with the interstage fluid. The bypass flow channel 128 can receive a fluid bypass flow from within a fluid circuit including the compressor 100. The bypass source of the fluid received by the bypass flow channel can be any one or more of a condenser, an economizer, an intercooler, a heat exchanger, or any other suitable fluid source at an intermediate pressure between the suction pressure and the discharge pressure of the compressor 100. The bypass injection port 114 can be an annular shape (surrounding the introduction port of the second stage blade 118). The bypass injection port 114 can be arranged between the return bend 110 and the second stage blade 118.

[0042] The flow control valve 116 is a valve configured to regulate the flow through the bypass flow injection port 114. The flow control valve 116 is configured to extend axially through the bypass flow injection port 114 so that the flow control valve 116 extends substantially perpendicular to the flow direction of the interstage flow from the anti-rotation vane 110 toward the second stage vane 118. The flow control valve 116 is configured to be able to inhibit the flow through the bypass flow injection port 114 in a closed position, for example, by including a portion having a thickness corresponding to the width of the bypass flow injection port 114 from the front end 124 to the rear end 126. In one embodiment, the flow control valve 116 is controlled together with the inlet guide vane 102. In one embodiment, the control of the flow control valve 116 is independent of the inlet guide vane 102.

[0043] The flow control valve 116 includes a front side 130 facing the return bend 110 and a rear side 132 facing the inlet of the second stage blade 118. The front side 130 includes a curved surface 134 extending toward a tip 136 of the flow control valve 116. The curved surface 134 can reduce the cross-sectional thickness of the flow control valve 116 from a thickness corresponding to the width of the bypass injection port 114 (the base at the curved surface 134 to a smaller thickness at the tip 136). The change in the cross-sectional thickness of the flow control valve 116 over the length of the curved surface 134 toward the tip 136 is configured to change the flow rate flowing through the bypass injection port based on the extension of the flow control valve 116. Figures 1A to 1D In the illustrated embodiment, the rear side 132 may be configured, for example, along a linear profile in the longitudinal direction of the flow control valve 116 , to always contact the rear end 126 of the bypass flow injection port 114 , so that all inflow interstage flow of the bypass flow is above the front side 130 .

[0044] In the case where the bypass injection port 114 has a ring shape, the flow control valve 116 can have a corresponding ring shape. In one embodiment, the flow control valve 116 is a single ring. In one embodiment, the flow control valve 116 includes a plurality of ring segments. In one embodiment, the flow control valve 116 includes one or more recessed portions, and the flow control valve 116 is configured to avoid contact between the flow control valve 116 and one or more anti-rotation blades 112 as the flow control valve 116 extends. In one embodiment, the flow control valve 116 can be moved from a fully open position in which the tip 136 is located within the bypass injection port 116 or the bypass flow channel 128, and a fully closed position in which the flow control valve 116 blocks the bypass injection port 114 from the front end 124 to the rear end 126.

[0045] In the fully open position of the flow control valve 116, the tip 136 of the flow control valve 116 does not extend through the bypass injection port 114. Therefore, interstage flow through the reverse rotation vanes 112 is not impeded, and there is minimal obstruction through the bypass injection port 114 of the flow control valve. The bypass fluid flows through the curved surface 134 to connect the interstage flow between the return bend 110 and the second stage vanes 118. The fully open position may be used when the compressor 100 is at or near full load flow.

[0046] The second stage blades 118 are used to implement the second stage of the compressor. The second stage blades 118 draw (fluid) in the combined interstage and bypass flow and discharge the fluid to the vortex volute 120. The second stage blades 118 can be rotated by the shaft 106, which is also used to rotate the first stage blades 104. Subsequently, the fluid at the vortex volute 120 can be discharged from the compressor 100 at the discharge cone 122.

[0047] In one embodiment, the bypass flow provided through the bypass flow injection port 114 may be received from an energy saving device, such as Figure 3B 100 and as described below. The economizer can be an economizer of a flash tank, wherein the flash or bypass gas rises and can be directed to the bypass flow channel 128. The gas from the economizer is directed to the bypass flow channel 128 to reduce or eliminate the presence of gas in the liquid that is delivered to the evaporator of the HVACR system including the compressor 100. This in turn can improve the absorption of energy in the evaporator by providing more saturated liquid working fluid without further subcooling. In a fully loaded cycle corresponding to the fully open position of the flow control valve 116, the pressure at the bypass injection port 114 can allow entrained vapor to be substantially removed from the working fluid in the economizer.

[0048] Figure 1B It is shown that when the flow control valve 116 is in the high flow position, Figure 1AA cross-sectional view of the compressor is shown in FIG. Figure 1B The high flow position shown in can be used for part load conditions, where the load is relatively close to the full load of the compressor 100. Figure 1B In the high flow position shown in FIG. 1 , the flow control valve 116 is axially extended so that the flow control valve 116 partially extends through the bypass injection port 114. Since the protrusion of the flow control valve 116 reduces the flow path size of the interstage flow, the front side 130 of the flow control valve 116 partially deflects the interstage flow in the compressor 100. Figure 1A Flow control valve 116 restricts flow through the bypass injection port to a greater extent than in the fully open position as shown and described above, where curved surface 134 reduces the orifice size by being closer to the front end 124 of bypass injection port 114. The rear side 132 of flow control valve 116 continues to contact the rear end 126 of bypass injection port 114, and all flow through bypass injection port 114 flows between the front end 124 of bypass injection port 114 and the front side 130 of flow control valve 116. Optionally, inlet guide vanes 102 may be rotated to partially obstruct first stage blades 104 of compressor 100.

[0049] Figure 1C shows that when the flow control valve is in the low flow position, Figure 1A A cross-sectional view of the compressor is shown in FIG. Figure 1C The low flow position shown in can be used for part load conditions, where the load is less than the full load of the compressor 100 and less than the flow control valve is in, for example Figure 1B loads in high traffic locations. Figure 1C In the low flow position shown, the flow control valve 116 is axially extended so that the flow control valve 116 extends along the bypass injection port 114. Figure 1B The high flow position shown extends further. The front side 130 of the flow control valve 116 causes the inter-stage flow in the compressor 100 to be deflected due to the protrusion of the flow control valve 116, further reducing the flow path size for the inter-stage flow. Figure 1B The high flow position shown and as described above, restricts the flow through the bypass injection port to a greater extent, and the curved surface 134 also reduces the hole size by even closer to the front end 124 of the bypass injection port 114. The rear side 132 of the flow control valve 116 continues to contact the rear end 126 of the bypass injection port 114, and all flow through the bypass injection port 114 flows between the front end 124 of the bypass injection port 114 and the front side 130 of the flow control valve 116. Optionally, the inlet guide vane 102 is Figure 1B Inlet guide vanes 102 may be rotated to further obstruct flow of first stage blades 104 of compressor 100 as compared to the position in the high flow position shown.

[0050] Figure 1D shows that when the flow control valve is in the closed position, Figure 1A When the compressor 100 is in a partial load condition of the compressor equal to or close to the minimum load of the compressor, the compressor 100 may be used as shown in FIG. Figure 1D . In the closed position, the flow control valve 116 partially or completely blocks the bypass flow injection port 114 from the front end 124 to the rear end 126. It should be understood that due to manufacturing tolerances, wear, etc., some leakage may exist even when the flow control valve 116 is configured to completely block the bypass flow and is in the closed position. In one embodiment, the size of the flow control valve 116 is such that it does not contact the bypass flow injection port 114, and allows some flow to continue to flow through the bypass flow injection port 114 even in the fully extended closed position. The extension line of the flow control valve 116 through the interstage inflow of the compressor 100 is the largest, reducing the size of the orifice through which the interstage flow passes from the return bend 110 toward the second stage blade 118. Therefore, this position imparts the maximum additional velocity to the interstage flow while prohibiting the bypass flow from merging into the interstage flow. Optionally, the inlet guide vane 102 can be rotated to further block the first stage blade 104 of the compressor 100, for example by pacing the inlet guide vane 102 in the minimum flow position.

[0051] Figure 2A FIG. 2 shows a cross-sectional view of a compressor 200 when the flow control valve is in a fully open position according to an embodiment. The compressor 200 may have a cylindrical structure such that FIG. 2A to FIG. 2D The cross-sectional views shown in are repeated or continuously rotated 360° around the axis A of the compressor 200 .

[0052] The compressor 200 is a multi-stage centrifugal compressor. The compressor 200 includes an inlet guide vane 202, in which a core flow of a fluid to be compressed is received. The compressor 200 includes a first-stage blade 204 driven by the rotation of a shaft 206, a diffuser 208 downstream of the first-stage blade 204, and a return bend 210 downstream of the diffuser 208. The compressor 200 also includes one or more reverse-rotation blades 212 downstream of the return bend 210. The compressor 200 includes a bypass injection port 214 and a flow control valve 216. The compressor 200 includes a second-stage blade 218 and a bypass injection port 214 downstream of the reverse-rotation blade 212, and a vortex volute 220 and a discharge cone 222 downstream of the second-stage blade 218.

[0053] Although the compressor 200 Figures 2A-2D2 is shown as a two-stage compressor, but the compressor according to the embodiment may include any number of stages, and the bypass injection port 214 and the flow control valve 216 are arranged in the flow path between any two stages of the compressor. For example, the compressor 200 may be a three-stage compressor, the bypass injection port 214 and the flow control valve 216 are arranged between the outlet of the second stage and the inlet of the third stage, and so on.

[0054] The compressor 200 may include one or more inlet guide vanes 202 to control the flow of the working fluid into the compressor 200. The inlet guide vanes 202 may be substantially similar to the inlet guide vanes 102 described above, and may be configured to be substantially similar to the inlet guide vanes 102 described above. Figures 1A to 1D . One or more inlet guide vanes 202 may be configured to obstruct or allow the working fluid to flow into the compressor 200. In one embodiment, each inlet guide vane 202 may be a rotating vane, for example, each rotating vane forms a circular cross-section, so that when all rotating vanes are in a closed position, the inlet guide vane 202 obstructs the inlet of the compressor 200. One or more inlet guide vanes 202 may be movable between a fully open position and a closed position. In the fully open position, the effect of the inlet guide vane 202 on the working fluid flowing into the compressor 200 may be minimized, for example by positioning the inlet guide vane 202 so that the plane of each vane is substantially parallel to the flow direction of the working fluid flowing into the inlet of the compressor 200. In one embodiment, one or more inlet guide vanes 202 may be continuously changed from a fully open position to a closed position.

[0055] The compressor 200 includes a first stage blade 204. The first stage blade 204 is driven by a shaft 206. The shaft 206 is rotated by a main motive force such as an electric motor. The first stage blade 204 is configured to draw working fluid flowing through one or more inlet guide vanes 202 when rotating and discharge the working fluid toward a diffuser 208.

[0056] The diffuser 208 receives the fluid discharged from the first stage blade 204 and directs the fluid toward the return bend 210. The return bend 210 changes the direction of the fluid flow so that the return bend 210 passes through the reverse rotation blade 212 toward the second stage blade 218.

[0057] One or more anti-rotation blades 212 are blades extending from the return bend 210 toward the second-stage blades 218. The anti-rotation blades 212 are shaped to direct the flow of the fluid when the flow flows toward the second-stage blades 218. The anti-rotation blades 212 may include a recessed portion configured to receive at least a portion of the flow control valve 216.

[0058] The bypass injection port 214 is a port configured to allow a bypass flow to be introduced into the interstage flow of the fluid through the compressor 200. The bypass injection port 214 includes a front end 224 and a rear end 226, wherein the front end 224 faces the return bend 210 and the rear end 226 faces the second stage blade 218. The bypass injection port 214 fluidly connects the bypass flow channel 228 to the interstage flow. The bypass flow channel 228 can receive a bypass flow of the fluid from within the fluid circuit including the compressor 200. The bypass flow source of the fluid received by the bypass flow channel 228 can be a condenser, an economizer, an intercooler, a heat exchanger, or any other suitable fluid source at an intermediate pressure between the suction pressure and the discharge pressure of the compressor 200. The bypass injection port 214 can be an annular shape surrounding the inlet of the second stage blade 218. The bypass injection port 214 can be disposed between the return bend 210 and the second stage blade 218.

[0059] The flow control valve 216 is a valve configured to regulate the flow through the bypass flow injection port 214. The flow control valve 216 is configured to extend axially through the bypass flow injection port 214, so that the flow control valve 216 extends substantially perpendicular to the flow direction of the interstage flow from the anti-rotation vane 212 toward the second stage vane 218. The flow control valve 216 is configured to be able to inhibit the flow through the bypass flow injection port 214 in a closed position, for example, by including a portion having a thickness corresponding to the width of the bypass flow injection port 214 from the front end 224 to the rear end 226. In one embodiment, the flow control valve 216 is controlled together with the inlet guide vane 202. In one embodiment, the control of the flow control valve 216 is independent of the inlet guide vane 202.

[0060] The flow control valve 216 includes a front side 230 facing the return bend 210 and a rear side 232 facing the inlet into the second stage blade 218. The front side 230 includes a curved surface 234 extending toward a tip 236 of the flow control valve 216. The curved surface 234 can cause the distance between the flow control valve 216 and the front end 224 of the bypass injection port 214 to change as the flow control valve 216 is axially extended or retracted.

[0061] The rear side 232 includes one or more flow passages 238 configured to allow flow from the bypass flow passage 228 through the bypass flow injection port 214 and be introduced into the interstage flow on the rear side 232 of the flow control valve 216. In one embodiment, the flow passage 238 includes one or more flow passages having an opening on the rear side 232 of the flow control valve 216. In one embodiment, the flow passage 238 is a cutout or scallop formed in the rear side 232 so that at some locations of the flow control valve 216, there is a gap between the rear side 232 and the rear end 224 of the bypass flow injection port 214.

[0062] In the fully open position of the flow control valve 216, the bypass flow passes through the bypass flow injection port 214 from the bypass flow passage 228 between the front end 224 of the bypass flow injection port 214 and the front side 230 of the flow control valve 216. The tip 236 of the flow control valve 216 is located in the bypass flow injection port 214 or retracted into the bypass flow passage 228, and the flow control valve 216 does not substantially affect the interstage flow from the return bend 210 to the second stage blade 218. Optionally, in Figure 2A In the fully open position shown in FIG. 1 , inlet guide vanes 202 may be in an open position where there is little resistance to flow into first stage vanes 204. For example, when compressor 200 is operating at or near full load flow, inlet guide vanes 202 may be in an open position where there is little resistance to flow into first stage vanes 204. Figure 2A In the embodiment shown in FIG. 2 , when Figure 2A In the fully open position shown, some or all of the bypass flow through the bypass injection port 214 may flow through the front side 230 of the flow control valve 216 .

[0063] The second stage blades 218 are used to achieve the second stage of compression. The second stage blades 218 draw (fluid) in the combined interstage and bypass flow and discharge the fluid to the vortex volute 220. The second stage blades 218 can be rotated by the shaft 206, which is also used to rotate the first stage blades 204. Subsequently, the fluid at the vortex volute 220 can be discharged from the compressor 200 at the discharge cone 222.

[0064] In one embodiment, the bypass flow provided through the bypass flow injection port 214 may be received from an energy saving device, such as Figure 3B 214 and as described below. The economizer can be an economizer of a flash tank, wherein the flash or bypass gas rises and can be directed to the bypass flow flow path 228. The gas from the economizer is directed to the bypass flow flow path 228, which can reduce or eliminate the presence of gas in the liquid, which is delivered to the evaporator of the HVACR system including the compressor 200. This in turn can improve the absorption of energy in the evaporator by providing more saturated liquid working fluid without further subcooling. In a full load cycle corresponding to the fully open position of the flow control valve 216, the pressure at the bypass injection port 214 can allow entrained vapor to be substantially removed from the working fluid in the economizer.

[0065] Figure 2B It is shown that when the flow control valve 216 is in the high flow position, Figure 2A A cross-sectional view of the compressor is shown in FIG. Figure 2B The high flow position shown in can be used for part load conditions, where the load is relatively close to the full load of the compressor 200. Figure 2BIn the high flow position shown in FIG, the flow control valve 216 is extended so that the tip 236 protrudes into the path of the interstage flow from the return bend 210 to the second vane 218, partially obstructing the path of the interstage flow. Figure 2B In the high flow position of the illustrated embodiment, a first gap exists between the front end 224 of the bypass injection port and the front end 230 of the flow control valve 216, and a second gap exists in the flow passage 238 between the rear side 232 of the flow control valve 216 and the rear side 226 of the bypass injection port 214. Each of the first and second gaps allows some of the bypass flow to merge into the interstage flow. The portion passing through the second gap exerts less pressure on the interstage flow due to its introduction on the rear side 232 of the flow control valve 216. Optionally, in the high flow position of the illustrated embodiment, a first gap exists between the front end 224 of the bypass injection port and the front end 230 of the flow control valve 216, and a second gap exists in the flow passage 238 between the rear side 232 of the flow control valve 216 and the rear side 226 of the bypass injection port 214. Each of the first and second gaps allows some of the bypass flow to merge into the interstage flow. The portion passing through the second gap exerts less pressure on the interstage flow due to its introduction on the rear side 232 of the flow control valve 216. Figure 2B In the high flow position shown, the inlet guide vane 202 may be in the high flow position, wherein the inlet guide vane 202 is in the high flow position. Figure 2A Compared to the fully open position shown, the inlet guide vanes 202 provide a higher resistance to flow into the first stage vanes 204, but are Figure 2C and 2D There is less resistance to flow than in the low flow or closed position shown in . Figure 2B In the high flow position shown in FIG. 2 , flow through the bypass injection port 214 may include flow through the front side 230 and the rear side 232 of the flow control valve.

[0066] Figure 2C The flow control valve 216 is shown in the low flow position. Figure 2A A cross-sectional view of the compressor is shown in FIG. Figure 2C The low flow position shown may be used for part load conditions where the load is less than the full load of the compressor 200 and is less than the flow control valve, e.g. Figure 2B Loads in high flow locations, Figure 2C In the low flow position shown, the flow control valve 216 is further extended to the interstage flow from the return bend 210 to the second blade 218. Figure 2B The flow control valve 216 thus provides greater resistance to interstage flow than in the high flow position shown. Figure 2C In the low flow position of the illustrated embodiment, a first gap exists between the front end 224 of the bypass injection port and the front end 230 of the flow control valve 216, and a second gap exists in the flow passage 238 between the rear side 232 of the flow control valve 216 and the rear side 226 of the bypass injection port 214. Figure 2B The high flow position shown shows the first and second gaps compared to the Figure 2C At a low flow position, the second gap is relatively larger than the first gap, and a larger proportion of the bypass flow flows through the second gap and merges into the interstage flow relative to the bypass flow flows through the first gap. Figure 2CIn the low flow position shown, the inlet guide vane 202 may be in the low flow position, wherein the inlet guide vane 202 is in the low flow position. Figure 2B Compared to the high flow position shown, the inlet guide vanes 202 provide a higher resistance to flow into the first stage vanes 204, but Figure 2D There is less resistance to flow than in the closed position shown. Figure 2B In the low flow position shown, the flow through the bypass injection port 214 can be primarily or completely exceeded by the back side 232 of the flow control valve. The shape of any one or more of the front side 230 and the flow passage 238 can be selected to control the relative flow introduced on the front side 230 or the back side 232 of the flow control valve 216, and how these relative amounts change as the flow control valve 216 moves from the fully open position through the closed position, such as Figures 2A-2D shown.

[0067] In one embodiment, the bypass flow channel 228 may receive bypass flow from an energy saving device, such as Figure 3B The economizer 314 is shown in FIG. 1 and is described below. Providing a flow passage 238 in the flow control valve 216 can allow the flow control valve 216 to control not only the flow introduced, but also the specific point in the bypass injection port 214 at which the bypass flow is introduced, as well as the pressure at the introduction point. Controlling the location of the bypass flow introduction point can control the relationship between the core flow and the bypass flow in the compressor. Controlling the introduction point can improve the efficiency of the economizer for different load conditions. When the compressor 200 is operating at a component load, the economizer can be used. Figure 2C 214 and the flow control valve 216. The low flow position shown. When the compressor 200 is operating under part load, the static pressure at the bypass injection port 214, especially between the front end 222 of the bypass injection port 214 and the front side 232 of the flow control valve 216, can be relatively elevated. In addition to the pipe losses and the fixed orifice pressure drop for the system, the pressure within the economizer is the static pressure at the injection location in the compressor 200. Therefore, the elevated pressure at the bypass injection port 214 can cause the economizer to be elevated, thereby reducing its effectiveness in removing flash or bypass gas from the fluid contained therein. The flow passage 238, with the flow passage 238 at Figure 1C The pressure on the front side 232 or the static pressure at the bypass injection port 214 in the illustrated embodiment is on the opposite side of the front side 232 (toward the interstage flow of the compressor 220) of the flow control valve 216, so the passage 238 is subjected to a reduced pressure. As described above, this reduced pressure (reduced pressure) at the injection point can correspondingly reduce the pressure within the economizer, thereby improving the release of flash or bypass gas from the liquid in the economizer and its removal from the working fluid flow through the evaporator. This improves heat transfer at the evaporator and can also reduce recompression losses in the compressor 200 in the system, which has a flow control valve 216 including the flow channel 238.

[0068] Figure 2D When the flow control valve 216 is in the closed position, Figure 2A When the compressor 200 is in a partial load condition of the compressor and close to the minimum load, it can be used Figure 2D . In the closed position, the flow control valve 216 partially or completely obstructs the bypass injection port 214 from the front end 224 to the rear end 226. It should be understood that due to manufacturing tolerances, etc., there may be some possible leakage even when the flow control valve 216 is in the closed position. In one embodiment, the size of the flow control valve 216 can be set so that it does not contact the bypass injection port 214 and allows some flow to flow through the gap between the bypass injection port 214 and the flow control valve 216. Any feature of the flow control valve 216 is configured to allow the introduction of bypass flow on the rear side 232 of the flow control valve 216, such as the flow channel 238, so that it (any feature of the flow control valve 216 described above) does not allow this flow (to flow through) when the flow control valve 216 is in the closed position. For example, as Figure 2D As shown, the rear side 232 in this embodiment forms a scalloped portion on the flow passage 238 of the size and positioning, so that when the flow control valve 216 is extended to the closed position, the rear side 232 contacts the rear end 226 of the bypass injection port 214. The extension line of the flow control valve 216 through the interstage inflow of the compressor 200 is the largest, reducing the size of the orifice of the interstage flow from the return bend 210 to the second stage impeller 218. Therefore, this position gives the interstage flow the maximum additional speed, while prohibiting the bypass flow from merging into the interstage flow. Optionally, the inlet guide vanes 202 can be rotated to further hinder the flow to the first stage blades 204 of the compressor 200, for example by moving the inlet guide vanes 202 in the minimum flow position.

[0069] Figure 3A A heating, ventilation, air conditioning, and refrigeration (HVACR) circuit is shown according to an embodiment. The HVACR circuit 300 includes a compressor 302 , a condenser 304 , an expander 306 , and an evaporator 308 .

[0070] The compressor 302 is a centrifugal compressor, for example Figures 1A to 1D The compressor 100 shown in FIG. 2A to FIG. 2D The compressor 200 shown in FIG. 1 and as described above.

[0071] Condenser 304 receives working fluid from compressor 302 and allows the working fluid to reject heat, such as to air or another heat exchange medium. In one embodiment, the fluid line from condenser 304 can return some of the working fluid of HVACR loop 300 to compressor 302 as a bypass flow provided to a bypass flow injection port of compressor 302, such as described above and Figures 1A to 2D The side stream injection port 114 or 214 is shown in FIG. Subsequently, the condensed working fluid of the condenser 304 may flow through the expander 306 .

[0072] Expander 306 expands the working fluid as it flows through HVACR circuit 300. Expander 306 may be any suitable expander of the working fluid within HVACR circuit 300, such as an expansion valve, one or more expansion orifices, or any other suitable expander for an HVACR circuit.

[0073] The evaporator 308 is a heat exchanger in which the working fluid of the HVACR loop 300 absorbs heat, for example, from the surrounding environment or a fluid to be cooled (such as water in a water chiller HVACR system). The evaporator 308 can be, for example, an indoor coil of an air conditioner or a heat exchanger configured to cool water used in an HVACR system including the HVACR loop 300.

[0074] The HVACR loop 300 may also include an intercooler 310. The intercooler 310 is a heat exchanger in which a working fluid from the HVACR loop exchanges heat with an interstage flow within the compressor 302. The working fluid that exchanges heat with the interstage flow in the intercooler 310 (from between the expander 306 and the evaporator 308 or between the evaporator 308 and the compressor 302) may originate from, for example, the evaporator 308. Some or all of the working fluid that exchanges heat with the interstage flow may then be reintroduced into the HVACR loop 300 downstream of the working fluid. In one embodiment, at least some of the working fluid from the intercooler 310 may be directed to a bypass flow flow path of the compressor 302 rather than returning to a normal flow path through the HVACR loop 300. The bypass flow flow path may be, for example, the bypass flow flow path 128 or the bypass flow flow path 228 of the compressors 100 and 200 described above, and in Figures 1A-1D and 2A-2D.

[0075] Figure 3B An energy-saving HVACR loop 320 is shown according to one embodiment. Figure 3B In the embodiment, the compressor 302, the condenser 304 and the evaporator 308 are included in the HVACR loop 300, and Figure 3A, in this embodiment, the compressor 302 is a multi-stage compressor. The HVACR loop 320 includes a first expander 312 and a second expander 314. Each of the first expander 312 and the second expander 314 can be any suitable expander for the working fluid within the HVACR loop 320, for example, an expansion valve, one or more expansion orifices, or any other suitable expansion device for the HVACR loop. The economizer 316 can be disposed between the first and second expanders 312, 314 so that the working fluid of the HVACR loop 320 is at an intermediate pressure at the economizer 316. The economizer 314 can be used as a bypass flow source introduced into the compressor 302, for example, flowing through a bypass flow flow path, such as the bypass flow flow path 128 or the bypass flow flow path 228 described above, and Figures 1A to 1D and FIG. 2A to FIG. 2D Shown in.

[0076] Figure 4 A cross-sectional view of a centrifugal compressor along an interstage flow path is shown according to one embodiment. The centrifugal compressor 400 includes a compressor housing 402. The compressor housing 402 partially defines an interstage flow path 404. The interstage flow path includes anti-rotation vanes 406 radially distributed around the interstage flow path 404. A flow control valve ring 408 extends into the interstage flow path 404, upstream of the lower stage inlet 410. As described above, the flow control valve ring 408 can be, for example, such as the flow control valve 116 or the flow control valve 216 described above, and Figures 1A to 1D and FIG. 2A to FIG. 2D Flow control valve ring 408 may be a single continuous ring or may be composed of multiple ring segments to provide an annular shape. The flow passing through flow control valve ring 408 is received at the lower stage inlet 410 and allowed to flow into the lower stage blades 412.

[0077] Figure 5 A cross-sectional view of a portion of a centrifugal compressor according to one embodiment is shown. In the view of the centrifugal compressor 500, the interaction between the anti-rotation vane 502 and the flow control valve ring 504 is shown. The anti-rotation vane 502 may be Figures 1A to 1D , FIG. 2A to FIG. 2D or Figure 4 The flow control valve ring 504 may be any of the reverse rotating blades shown. Figures 1A to 1D , FIG. 2A to FIG. 2D or Figure 4Any flow control valve shown. The flow control valve ring 504 includes recessed portions 506, each recessed portion 506 is configured to accommodate one of the anti-rotation blades 502, so that the flow control valve ring 504 can extend to the flow path including the anti-rotation blades 502 without mechanically interfering with the anti-rotation blades 502. In one embodiment, a recessed portion corresponding to the recessed portion 506 can be included on each anti-rotation blade 502, so that the anti-rotation blade 502 does not contact the flow control valve ring 504 due to its extension. In one embodiment, the recessed portion 506 is provided on the anti-rotation blade 502 together with the corresponding recessed portion. In this embodiment, the recessed portion 506 can have a depth that is less than the entire height of the area where the flow control valve ring 504 can contact the anti-rotation blade 502, and the recess in the anti-rotation blade has a depth that allows it to accommodate any portion of the flow control valve ring 504 that would otherwise contact the anti-rotation blade 502 in the absence of the recessed portion.

[0078] Example:

[0079] It should be understood that any of Examples 1 to 12 may be combined with any of Examples 13-19.

[0080] Embodiment 1. A centrifugal compressor, comprising:

[0081] First stage blades;

[0082] Second stage blades;

[0083] a bypass flow injection port located between the first stage blade and the second stage blade, the bypass flow injection port being configured to receive a bypass flow of a fluid; and

[0084] A flow control valve configured to extend and retract through a side stream injection port, wherein:

[0085] The flow control valve has a curved surface facing the flow direction from the first-stage blade to the second-stage blade; and

[0086] The flow control valve is configured to extend through the bypass injection port between an open position and a closed position, wherein in the open position a bypass flow of a fluid can flow through the bypass injection port, and in the closed position the flow control valve blocks the flow rate of the bypass flow of the fluid from flowing through the bypass injection port.

[0087] Embodiment 2. The centrifugal compressor according to embodiment 1, wherein the flow control valve has a ring shape.

[0088] Embodiment 3. The centrifugal compressor according to any one of embodiments 1 to 2 comprises a plurality of side stream injection ports and a plurality of flow control valves.

[0089] Embodiment 4. A centrifugal compressor according to any one of embodiments 1 to 3, wherein in the open position, the tip of the flow control valve at the end of the curved surface is located within the side stream injection port.

[0090] Embodiment 5. The centrifugal compressor according to any one of embodiments 1 to 4, wherein the flow control valve extends and retracts in a direction substantially perpendicular to a flow direction from the first stage blades to the second stage blades.

[0091] Embodiment 6. The centrifugal compressor according to any one of embodiments 1 to 5, further comprising one or more counter-rotation blades between the first stage blades and the second stage blades.

[0092] Embodiment 7. The centrifugal compressor of embodiment 6, wherein the flow control valve comprises one or more recessed portions, each of the one or more recessed portions being configured to accommodate at least a portion of any one of the one or more anti-rotation blades.

[0093] Embodiment 8. A centrifugal compressor according to any one of embodiments 6 to 7, wherein each of the one or more anti-rotation blades comprises one or more recessed portions, and each of the one or more recessed portions is configured to accommodate at least a portion of the flow control valve.

[0094] Embodiment 9. The centrifugal compressor of any one of embodiments 1 to 8, wherein the flow control valve has a linear meridian profile on a side opposite to the curved surface, the linear meridian profile of the curve contacts an edge of the side flow injection port.

[0095] Embodiment 10. A centrifugal compressor according to any one of embodiments 1 to 9, wherein the side of the flow control valve opposite to the curved surface is configured so that when the flow control valve is between an open position and a closed position, fluid can flow through the flow control valve on the side of the flow control valve opposite to the curved surface.

[0096] Embodiment 11. The centrifugal compressor according to embodiment 10, wherein the side of the flow control valve opposite to the curved surface comprises a second curved surface.

[0097] Embodiment 12: A centrifugal compressor according to any one of embodiments 10 to 11, wherein the side of the flow control valve opposite to the curved surface comprises one or more flow channels, wherein the flow channels are configured to allow a bypass flow rate of the fluid.

[0098] Embodiment 13. A heating, ventilation, air conditioning and refrigeration (HVACR) circuit, comprising:

[0099] Centrifugal compressors;

[0100] Condenser;

[0101] expander; and

[0102] Evaporator,

[0103] The centrifugal compressors include:

[0104] First stage blades;

[0105] Second stage blades;

[0106] a bypass flow injection port located between the first stage blade and the second stage blade, the bypass flow injection port being configured to receive a bypass flow of a fluid; and

[0107] a flow control valve configured to extend and retract through the bypass injection port,

[0108] The flow control valve has a curved surface facing the flow direction from the first-stage blade to the second-stage blade; and

[0109] The flow control valve is configured to extend through the bypass injection port between an open position and a closed position, wherein in the open position a bypass flow of a fluid can flow through the bypass injection port, and in the closed position the flow control valve blocks the flow rate of the bypass flow of the fluid from flowing through the bypass injection port.

[0110] Embodiment 14. The HVACR circuit of embodiment 13, wherein the bypass flow of the fluid flows from the condenser to the bypass flow injection port.

[0111] Embodiment 15. The HVACR circuit of embodiment 13, further comprising an economizer, and wherein a bypass flow of fluid flows from the economizer to the bypass flow injection port.

[0112] Embodiment 16. The HVACR circuit of embodiment 13, further comprising an intercooler, and wherein the bypass flow of the fluid is from the intercooler to the bypass flow injection port.

[0113] Embodiment 17. The HVACR circuit of any one of embodiments 13 to 16, wherein the flow control valve has a ring shape.

[0114] Embodiment 18. The HVACR circuit of any one of embodiments 13 to 17, wherein the flow control valve has a linear meridian profile on a side opposite to the curved surface, the linear meridian profile contacting an edge of the side flow injection port.

[0115] Embodiment 19. An HVACR circuit according to any one of embodiments 13 to 17, wherein the side of the flow control valve opposite the curved surface is configured so that when the flow control valve is between an open position and a closed position, fluid can flow through the flow control valve on the side of the flow control valve opposite the curved surface.

[0116] The embodiments disclosed in this application are considered to be illustrative in all embodiments, rather than restrictive. The scope of the present invention is indicated by the appended claims rather than the foregoing content; and all changes within the meaning and equivalent range of the claims are included therein.

Claims

1. A centrifugal compressor, It is characterized in that include: first leaf; second blade; a side flow injection port, the side flow injection port being located between the first blade and the second blade, the side flow injection port being configured to receive a side flow; as well as a flow control valve configured to extend and retract through the side stream injection port, wherein: The flow control valve has a curved surface facing the flow direction from the first blade to the second blade; The flow control valve is configured to extend flow from the first vane to the second vane; and The flow control valve is configured to extend through the bypass stream injection port between an open position and a closed position, wherein in the open position, the bypass stream is able to flow through the bypass stream injection port, and in the closed position, the flow control valve blocks the flow of the bypass stream through the bypass stream injection port.

2. The centrifugal compressor according to claim 1, It is characterized in that The flow control valve has a ring shape.

3. The centrifugal compressor according to claim 1, It is characterized in that It includes a plurality of the side stream injection ports and a plurality of the flow control valves.

4. The centrifugal compressor according to claim 1, It is characterized in that In the open position, the tip of the flow control valve at the end of the curved surface is located within the side stream injection port.

5. The centrifugal compressor according to claim 1, It is characterized in that The flow control valve extends and retracts in a direction substantially perpendicular to a flow direction from the first vane to the second vane.

6. The centrifugal compressor according to claim 1, It is characterized in that Also included is one or more counter-rotating blades between the first blade and the second blade.

7. The centrifugal compressor according to claim 6, It is characterized in that The flow control valve includes one or more recessed portions, each of the one or more recessed portions being configured to receive at least a portion of any one of the one or more counter-rotation blades.

8. The centrifugal compressor according to claim 6, It is characterized in that Each of the one or more anti-rotation blades includes one or more recessed portions, each of the one or more recessed portions being configured to receive at least a portion of the flow control valve.

9. The centrifugal compressor according to claim 1, It is characterized in that The flow control valve has a linear profile on a side opposite to the curved surface, and the linear profile contacts an edge of the side flow injection port.

10. The centrifugal compressor according to claim 1, It is characterized in that The side of the flow control valve opposite the curved surface is configured such that fluid can flow through the flow control valve on the side of the flow control valve opposite the curved surface when the flow control valve is between an open position and a closed position.

11. The centrifugal compressor according to claim 10, It is characterized in that The side of the flow control valve opposite to the curved surface includes a second curved surface.

12. The centrifugal compressor according to claim 10, It is characterized in that The side surface of the flow control valve opposite to the curved surface includes one or more flow channels, and the flow channels are configured to allow the flow rate of the bypass flow.

13. A heating, ventilation, air conditioning and refrigeration (HVACR) circuit, It is characterized in that include: Centrifugal compressors; Condenser; expander; as well as Evaporator, The centrifugal compressors include: first leaf; second blade; a bypass flow injection port located between the first blade and the second blade, the bypass flow injection port being configured to receive a bypass flow; and a flow control valve configured to extend and retract through the side stream injection port, The flow control valve has a curved surface facing the flow direction from the first blade to the second blade; The flow control valve is configured to extend flow from the first vane to the second vane; and The flow control valve is configured to extend through the bypass flow injection port between an open position in which a bypass flow is able to flow through the bypass flow injection port and a closed position in which the flow control valve blocks flow of the bypass flow through the bypass flow injection port.

14. A heating, ventilation, air conditioning and refrigeration circuit according to claim 13, It is characterized in that The side stream flows from the condenser to the side stream injection port.

15. The heating, ventilation, air conditioning and refrigeration circuit according to claim 13, It is characterized in that An energy saver is also included, and wherein the side stream flows from the energy saver to the side stream injection port.

16. The heating, ventilation, air conditioning and refrigeration circuit according to claim 13, It is characterized in that An intercooler is also included, and wherein the bypass flow flows from the intercooler to the bypass flow injection port.

17. The heating, ventilation, air conditioning and refrigeration circuit according to claim 13, It is characterized in that The flow control valve has a ring shape.

18. The heating, ventilation, air conditioning and refrigeration circuit according to claim 13, It is characterized in that The flow control valve has a linear profile on a side opposite to the curved surface, and the linear profile contacts an edge of the side flow injection port.

19. The heating, ventilation, air conditioning and refrigeration circuit according to claim 13, It is characterized in that The side of the flow control valve opposite the curved surface is configured such that the bypass flow can flow through the flow control valve on the side of the flow control valve opposite the curved surface when the flow control valve is between an open position and a closed position.

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