BULBLESS EXPANSION VALVE WITH INTEGRATED BYPASS CHECK VALVE

Abstract

An expansion valve including a valve body having an inlet, an outlet, a main flow passage extending from inlet to outlet, and a metering orifice in the at least one main flow passage. A power element controls movement of a valve member relative to the metering orifice to control flow of operating fluid passing across the metering orifice when the valve is operating in a forward flow expansion mode. The valve body includes an internal bypass flow passage that bypasses the metering orifice, and a bypass check valve is arranged internally of the valve body in the bypass flow passage. The bypass check valve is configured to open at least partially in response to operating fluid flowing in a reverse flow bypass mode in which activation of the bypass check valve opens the bypass flow passage to permit operating fluid to bypass the metering orifice in the reverse bypass mode.

Claims

1. A bulbless-style expansion valve, comprising: a valve body having a first inlet, a first outlet, a first main flow passage extending from the first inlet to the first outlet, a metering orifice in the first main flow passage between the first inlet and the first outlet, a second inlet, a second outlet, and a second main flow passage extending from the second inlet to the second outlet, the second main flow passage being separate from the first main flow passage; a valve member movable in the valve body relative to the metering orifice to control flow of operating fluid passing through the first main flow passage and across the metering orifice as operating fluid flows from the first inlet to the first outlet when the valve is operating in a forward flow expansion mode; a power element operatively coupled to the valve member and configured to control movement of the valve member at least partially in response to changes in temperature and pressure of operating fluid passing through the second main flow passage from the second inlet to the second outlet when the valve is operating in the forward flow expansion mode; a bypass flow passage extending internally through the valve body and bypassing the metering orifice; and a bypass check valve arranged internally of the valve body in the bypass flow passage, the bypass check valve being configured to activate at least partially in response to operating fluid flowing in a reverse flow bypass mode in which activation of the bypass check valve opens the bypass flow passage to permit operating fluid to bypass the metering orifice in the reverse flow bypass mode; wherein the first outlet of the first main flow passage and an inlet of the bypass flow passage share a common external connection port of the valve body which is configured to connect a conduit of a system incorporating the valve.

2. The expansion valve according to claim 1, wherein the check valve and bypass flow passage are arranged to provide hermetic sealing in which any leakage past the check valve does not escape to an external environment outside of the valve and/or system in which the valve is incorporated.

3. The expansion valve according to claim 1, wherein the bypass check valve is at least partially arranged in-line with the first main flow passage.

4. (canceled)

5. The expansion valve according to claim 1, wherein the first inlet of the first main flow passage and an outlet of the bypass flow passage share a second common external connection port of the valve body which is configured to connect a second conduit of the system incorporating the valve.

6. The expansion valve according to claim 1, wherein the first main flow passage includes an upstream portion that is upstream of the metering orifice when the valve is operating in the forward flow expansion mode, wherein the bypass flow passage includes a downstream portion that is downstream of a check valve seat that the bypass check valve engages when closed, and wherein at least a portion of the upstream portion of the first main flow passage and at least a portion of the downstream portion of the bypass flow passage are a commonly shared passage in the valve body.

7. The expansion valve according to claim 1, wherein the first main flow passage includes a downstream portion this that is downstream of the metering orifice when the valve is operating in the forward flow expansion mode, wherein the bypass flow passage includes an upstream portion that is upstream of a check valve seat that the bypass check valve engages when closed, and wherein at least a portion of the downstream portion of the first main flow passage and at least a portion of the upstream portion of the bypass flow passage are a commonly shared passage in the valve body.

8. The expansion valve according to claim 7, wherein the bypass flow passage includes a first upstream portion that is shared with a portion of the downstream portion of the first main flow passage, and wherein the bypass flow passage includes a second upstream portion that branches off from the first main flow passage and extends internally within the valve body to the check valve seat.

9. The expansion valve according to claim 8, wherein the bypass check valve is inserted into a vertical bore having an opening in a bottom of the valve body, wherein at least part of the bore is plugged.

10. The expansion valve according to claim 1, wherein the bypass check valve is inserted into a vertical bore having an opening in the second main flow passage.

11. The expansion valve according to claim 1, wherein the bypass check valve is inserted into an inclined bore having an opening in a sidewall of the valve body.

12. The expansion valve according to claim 5, wherein the bypass check valve is inserted into a bore having an opening in a recessed portion of the second common external connection port of the first inlet of the first main flow passage and the outlet of the bypass flow passage.

13. The expansion valve according to claim 1, wherein the first main flow passage includes a downstream portion this is downstream of the metering orifice when the valve is operating in the forward flow expansion mode, wherein the bypass flow passage includes an upstream portion that is upstream of a check valve seat that the bypass check valve engages when closed, and wherein the upstream portion of the bypass flow passage is fluidly separated from the downstream portion of the first main flow passage.

14. The expansion valve according to claim 13, wherein the bypass flow passage includes a through-opening in the valve body that is downstream of the check valve seat, the through-opening being configured to fluidly connect the upstream portion of the bypass flow passage to a downstream portion of the bypass flow passage when the bypass check valve is activated to open.

15-16. (canceled)

17. The expansion valve according to claim 1, wherein: the power element comprises a casing and a flexible diaphragm at least partially within the casing, the flexible diaphragm being operatively coupled to the valve member and being configured to flex at least partially in response to changes in temperature and pressure of operating fluid passing through the second main flow passage when the valve is operating in the forward flow expansion mode; and/or wherein the metering orifice is formed as an adjustable flow restrictive opening in an annular region between a valve seat in the first main flow passage and an engagement portion of the valve member; and/or wherein the check valve comprises a stationary plug and a plunger that is movable relative to the plug.

18-21. (canceled)

22. A bulbless-style expansion valve, comprising: a valve body having a first inlet, a first outlet, a first main flow passage extending from the first inlet to the first outlet, a metering orifice in the first main flow passage between the first inlet and the first outlet, a second inlet, a second outlet, and a second main flow passage extending from the second inlet to the second outlet, the second main flow passage being separate from the first main flow passage; a valve member movable in the valve body relative to the metering orifice to control flow of operating fluid passing through the first main flow passage and across the metering orifice as operating fluid flows from the first inlet to the first outlet when the valve is operating in a forward flow expansion mode; a power element operatively coupled to the valve member and configured to control movement of the valve member at least partially in response to changes in temperature and pressure of operating fluid passing through the second main flow passage from the second inlet to the second outlet when the valve is operating in the forward flow expansion mode; a bypass flow passage extending internally through the valve body and bypassing the metering orifice; and a bypass check valve arranged internally of the valve body in the bypass flow passage, the bypass check valve being configured to activate at least partially in response to operating fluid flowing in a reverse flow bypass mode in which activation of the bypass check valve opens the bypass flow passage to permit operating fluid to bypass the metering orifice in the reverse flow bypass mode; wherein the first inlet of the first main flow passage and an outlet of the bypass flow passage share a common external connection port of the valve body which is configured to connect a conduit of a system incorporating the valve.

23. The expansion valve according to claim 22, wherein the check valve and bypass flow passage are arranged to provide hermetic sealing in which any leakage past the check valve does not escape to an external environment outside of the valve and/or system in which the valve is incorporated.

24. The expansion valve according to claim 22, wherein the bypass check valve is at least partially arranged in-line with the first main flow passage.

25. The expansion valve according to claim 22, wherein the first main flow passage includes an upstream portion this is upstream of the metering orifice when the valve is operating in the forward flow expansion mode, wherein the bypass flow passage includes a downstream portion that is downstream of a check valve seat that the bypass check valve engages when closed, and wherein at least a portion of the upstream portion of the first main flow passage and at least a portion of the downstream portion of the bypass flow passage are a commonly shared passage in the valve body.

26. The expansion valve according to claim 22, wherein the bypass check valve is inserted into a vertical bore having an opening in a bottom of the valve body, wherein at least part of the bore is plugged; or wherein the bypass check valve is inserted into a vertical bore having an opening in the second main flow passage; or wherein the bypass check valve is inserted into an inclined bore having an opening in a sidewall of the valve body; or wherein the bypass check valve is inserted into a bore having an opening in a recessed portion of the common external connection port of the first inlet of the first main flow passage and the outlet of the bypass flow passage.

27. The expansion valve according to claim 22, wherein the first main flow passage includes a downstream portion this is downstream of the metering orifice when the valve is operating in the forward flow expansion mode, wherein the bypass flow passage includes an upstream portion that is upstream of a check valve seat that the bypass check valve engages when closed, and wherein the upstream portion of the bypass flow passage is fluidly separated from the downstream portion of the first main flow passage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The annexed drawings, which are not necessarily to scale, show various aspects according to the present disclosure.

[0015] FIG. 1 is a cross-sectional side view of an exemplary thermal expansion valve (TEV) according to the present disclosure, which is incorporated into a system, and which is shown operating in a forward flow expansion mode with metering functionality while the system is cooling.

[0016] FIG. 2 is another cross-sectional side view of the TEV in FIG. 1, which is shown operating in a reverse flow mode with bypass functionality while the system is heating.

[0017] FIG. 3 is an enlarged view of the cross-section shown in FIG. 2, but in the forward flow expansion mode according to FIG. 1.

[0018] FIG. 4A is a perspective view of the TEV in FIGS. 1-3, and FIG. 4B is the opposite perspective view of the TEV.

[0019] FIG. 5A is an enlarged quarter section view of the TEV in FIGS. 1-4B showing the forward flow expansion mode.

[0020] FIG. 5B is an enlarged quarter section view of the TEV in FIGS. 1-4B showing the reverse flow bypass mode.

[0021] FIG. 6 is a cross-sectional side view of another exemplary TEV according to the present disclosure.

[0022] FIG. 7 is a cross-sectional side view of another exemplary TEV according to the present disclosure.

[0023] FIG. 8 is a cross-sectional side view of another exemplary TEV according to the present disclosure.

DETAILED DESCRIPTION

[0024] The principles and aspects according to the present disclosure have particular application to bulbless-style thermal expansion valves (TEVs) for use in heat pump applications, and thus will be described below chiefly in this context. It is understood, however, that the principles and aspects according to the present disclosure may be applicable to other TEVs for heat pump systems, such as residential, commercial, or automotive air conditioning or refrigeration systems, for example.

[0025] FIGS. 1-5B show an exemplary bulbless-style expansion valve with integrated check valve 20 (also referred to as a thermal expansion valve or TEV 20). FIG. 1 shows a schematic diagram of a refrigerant system 10 incorporating the exemplary TEV 20 in which the system 10 is running in a forward flow cooling mode and a first cross-sectional view of the TEV 20 is shown metering and expanding operating fluid through the valve. FIGS. 3 and 5A are enlarged views from different cross-sections of the TEV 20 still showing operation in the forward flow expansion mode, as described in further detail below. FIG. 2 shows a schematic diagram of the system 10 operating in a reverse flow heat pump mode and second cross-sectional view of the TEV 20 is shown bypassing operating fluid. FIG. 5B is an enlarged view from a different cross-section of the TEV 20 showing the bypass functionality when operating in the reverse flow bypass mode, as described in further detail below.

[0026] Referring initially to FIG. 1, the exemplary TEV 20 generally includes a valve body 22 having a first inlet 24, a first outlet 26, and a first main flow passage 28 extending from the first inlet 24 to the first outlet 26. In the illustrated embodiment, the TEV 20 is arranged between a first heat exchanger 12 and a second heat exchanger 14 of the system 10. The TEV first inlet 24 is fluidly connected to an outlet of the first heat exchanger 12 to receive operating fluid in the forward flow expansion mode, and the TEV first outlet 26 is fluidly connected to an inlet of the second heat exchanger 14. When the system 10 is operating to cool with the TEV 20 in the forward flow expansion mode, the second heat exchanger 14 serves as an evaporator contained within a space to be cooled (e.g., indoors), and the first heat exchanger 12 serves as a condenser that is located outside of the cooled space (e.g., outdoors). As is conventional in a refrigerant system, the system 10 also includes a compressor 16 positioned between the outlet of the second heat exchanger 14 (evaporator) and the inlet of the first heat exchanger 12 (condenser). In the forward flow mode, the operating fluid, such as a suitable refrigerant, circulates through the system 10 and is compressed by the compressor 16 which raises the temperature and pressure of the refrigerant. The then hot pressurized refrigerant gas flows through the first heat exchanger 12 (condenser) to allow the refrigerant to dissipate heat. The first heat exchanger 12 lowers the refrigerant temperature such that the refrigerant condenses into a liquid which passes to the first inlet 24 of the TEV 20.

[0027] In the forward flow expansion mode, the TEV 20 is configured as a refrigerant modulating valve that controls expansion of the liquid refrigerant received from the first heat exchanger 12 (condenser), whereby some of the refrigerant evaporates and transforms into a two-phase vapor-liquid mixture. To provide such expansion, the TEV 20 includes a metering orifice 30 arranged in the first main flow passage 28 which forms a flow restriction in cooperation with a valve member 31 that creates a region of high pressure in an inlet portion 28a of the main flow passage 28 between the first inlet 24 and the metering orifice 30, and a region of low pressure in an outlet portion 28b of the main flow passage 28 between the metering orifice 30 and the first outlet 26. The refrigerant expands and transforms to the two-phase mixture as it moves across the metering orifice from the high-pressure region to the low-pressure region.

[0028] The cold liquid-vapor refrigerant passes through the first outlet 26 downstream of the TEV 20 into circuits of the second heat exchanger 14 (evaporator), thus absorbing heat from inside the space that is to be cooled. The second heat exchanger 14 (evaporator) could be located, for example, in the plenum of a forced air residential or commercial air conditioning system through which air is blown for cooling the interior of the residence or building. In automotive applications, the second heat exchanger 14 (evaporator) typically is located in the dashboard inside the vehicle cabin. In the forward expansion mode, the cold liquid-vapor mixture absorbs heat from the second heat exchanger 14 (evaporator) thereby returning the refrigerant to a gaseous vapor state. The refrigerant vapor is then cycled back to the compressor 16 through a suction line of the system 10.

[0029] In the illustrated embodiment, the valve body 22 of the TEV 20 forms at least a portion of the fluid (suction) line between the second heat exchanger 14 and the compressor 16. As shown, the valve body 22 includes a second inlet 32 fluidly connected to the outlet of the second heat exchanger 14 (evaporator), and a second outlet 34 fluidly connected to the inlet of the compressor 16. The valve body 22 forms a second main flow passage 36 extending from the second inlet 32 to the second outlet 34, in which this second main flow passage 36 is fluidly separated from the first main flow passage 28 in the valve body 22. To prevent leakage of operating fluid, the TEV 20 is sealed in the system 10, such as by providing suitable connections at the respective inlets 24, 32 and outlets 26, 34. For example, the fluid lines of the system 10 may include conduit or piping that is welded, brazed, or otherwise sealed to the inlets/outlets of the valve body 22.

[0030] To control the amount of expansion across the metering orifice 30, the valve member 31 is movable in the valve body 22 relative to the metering orifice 30. The metering orifice 30 and/or valve member 31 may have any suitable structure(s) for opening, closing, or modulating flow through the first main flow passage 28 to control the amount of expansion by the TEV 20. In the illustrated embodiment, the metering orifice 30 is formed as an adjustable flow restrictive opening in the annular region between a valve seat 38 in the first main passage 28 and a poppet or pin portion of the valve member 28 that serves as an engagement portion of the valve member 28 that is operative to engage the valve seat 38 and close the TEV 20. The metering orifice 30 and thus flow through the first main passage 28 can be closed when the valve member 31 engages the valve seat 38.

[0031] The TEV 20 also includes a power element 40 that serves as an actuator operatively coupled to the valve member 31 for controlling movement of the valve member 31. The power element 40 is operatively mounted to the valve body 22, and include a casing 42 that forms an enclosure which contains a flexible diaphragm 44. The diaphragm 44 may be a thin metal sheet that fluidly separates the casing enclosure into a first (upper) chamber 46 and a second (lower) chamber 48. The first chamber 46 is charged with a charge fluid, such as a refrigerant, and the second chamber 48 is in communication with the operating fluid flowing through the second main flow passage 36. A dome 47 also may be included which is in fluid communication with the first chamber 46 to also contain the charge fluid and help to reduce the responsiveness of the valve. A ballast material (not shown) may be contained within the dome 47 to further reduce reactivity and enable better control of the valve. The changes in temperature and pressure of the operating fluid (gaseous vapor) flowing through the second main flow passage 36 is communicated to a (lower) side of the diaphragm 44 via the second (lower) chamber 48 which acts against the pressure on the opposite (upper) side of the diaphragm from the charge fluid in the first (upper) chamber 46. The TEV 20 may further include an adjustment mechanism 49, such as a spring-biased adjuster including a spring 49a and pin 49b for adjusting spring force, whereby the spring force urges the valve member 31 toward closed and combines with fluid pressure at the underside of the diaphragm 44 for counteracting the pressure from the first (upper) chamber 46 and thereby setting a desired control setpoint of the TEV 20. As the temperature and pressure of the operating fluid (vapor) flowing through the second main passage 36 changes, the charge in the power element 40 reacts to these pressure and temperature changes, exerting force on the diaphragm 44 and causing the diaphragm 44 to flex. This, in turn, exerts force on the valve member 31 causing the valve member 31 to move relative to the metering orifice 30. As such, the power element 40 responds to sensing high temperature flow through the second main passage 36 by adjusting the valve member 31 to increase flow through the first main passage 28, and responds to sensing low temperature flow through the second main passage 36 by adjusting the valve member 31 to decrease flow through the first main passage 28. In this manner, the power element 40 is configured to control movement of the valve member 31 at least partially in response to changes in temperature and pressure of operating fluid passing through the second main flow passage 36.

[0032] Referring now to FIG. 2, the exemplary vapor-compression system 10 also can be used as a heat pump when run in reverse. As shown in the illustrated embodiment, the system 10 may include a four-way reversing valve 18 that is configured to control forward or reverse flow through the system 10. In a reverse flow heating mode, the first heat exchanger 12 serves as an evaporator which draws heat into the refrigerant and transforms it into a superheated vapor which is passed to the compressor 16. The refrigerant leaves the compressor 16 as a superheated vapor and the second heat exchanger 14 (now serving as a condenser) extracts heat from the refrigerant into the space to be heated (e.g., indoors). The heat extracted from the refrigerant condenses the superheated vapor into a liquid, which exits the outlet of the second heat exchanger 14 and flows to the TEV 20.

[0033] As is apparent in the illustrated embodiment, in the reverse flow direction, the liquid refrigerant flow into the first outlet 26 would force the valve member 31 toward the valve seat 38 and undesirably restrict flow. Accordingly, the exemplary TEV 20 provides a unique bypass arrangement including an internal bypass passage 50 that extends through the valve body 22 and bypasses the flow restriction at the metering orifice 30 in the reverse flow mode. The unique bypass arrangement also includes an integrated check valve 52 arranged within the bypass passage 50 that is configured to open the bypass passage 50 when the system is operated in the reverse flow heat pump mode. Such an integrated check valve 52 is configured to seal the bypass passage 50 in the forward flow expansion mode (as shown in FIGS. 3 and 5A) so that flow passes through the first main flow passage 28 and across the metering orifice 30, and is configured to automatically activate to open the bypass passage 50 in response to reverse flow (as shown in FIGS. 2 and 5B). As such, integrating the reverse flow check valve 52 into the TEV 20 enables use of the TEV 20 in the system in both bypass and expansion modes. To expand the refrigerant in the system heating mode, another TEV between the TEV 20 and the first heat exchanger 12 (evaporator) may be provided, which may be the same as TEV 20 but arranged in reverse to provide expansion in the system reverse flow mode.

[0034] The bypass arrangement including the configuration of the bypass passage 50 and/or the configuration of the check valve 52 may have any suitable design as may be desired for the particular application. In exemplary embodiments, the bypass arrangement provides a hermetic seal in which all leak paths are contained to within the valve body 22 and/or to the connections with the system piping to prevent a direct leak to ambient external environment. For example, as best shown in FIGS. 4A and 4B, the bypass passage 50 shares at least a first connection port 54 with the first outlet 26, and shares at least a second connection port 56 with the first inlet 24. The first connection port 54 is connected with conduit or piping that is connected to the second heat exchanger 14, and the second connection port 56 is connected with conduit or piping that is connected to the first heat exchanger 12. As shown in FIGS. 3 and 5B, the bypass passage 50 may include an upstream portion 50a that shares the connection portion 54 with the first outlet 26, but the upstream portion 50a has a separate flow path than the outlet portion 28b of the first main flow passage 28 and thus routes around the metering orifice 30 where the valve member 31 creates a flow restriction with the valve seat 38. Also as shown in FIGS. 3 and 5B, the bypass passage 50 may include an opening 58, such as a through-passage, that fluidly connects the upstream portion 50a to the inlet portion 28a of the first main passage 28, such that the inlet portion 28a is shared with the bypass passage 50 and thus the inlet portion 28a also serves as a downstream portion 50b of the bypass flow passage 50 in the reverse flow direction. Such sharing of flow paths helps to reduce the size of the valve body 22 and reduces the possibility of leakage to the external environment. In the illustrated embodiment, the opening 58 is opened or closed with the check valve 52. When operating in the forward expansion mode, the check valve 52 closes the opening 58, thus closing the portion 50a of the bypass flow passage 50 and forcing flow across the metering orifice 30. Also as best shown in FIGS. 3 and 4A, the check valve 52 may be arranged completely internally within the valve body 22, and may be inserted via an internal bore 60 having an insertion opening 62 that is fluidly connected with the connection port 56. As such, any leakage of the check valve 52 would leak internally within the system piping, instead of externally to ambient environment.

[0035] Referring particularly to FIG. 3, in the illustrated embodiment, the check valve 52 is configured as a plunger-style check valve 52, including a stationary plug 64 arranged in the internal bore 60, and a plunger 66 that is movable within the stationary plug 64. The plug 64 includes at least one seal 67 that restricts leakage out of the bore 60, and the plunger 66 includes at least one seal 68 that engages a valve seat 70 upstream of the opening 58 to open or close the bypass passage 50. The plunger-style check valve 52 is configured such that motion of the plunger 66 is controlled by the cooperation between a bore 72 in the plug 64 and a stem 73 of the plunger 66. The fit between the bore 72 and stem 73 permits linear motion of the plunger 66 with a hard stop in the bore 72 when fully retracted, and the valve seat 70 provides a hard stop for the plunger 66 in the extended position. When the check valve 52 is activated (in the retracted position) for reverse flow, refrigerant can flow into the connection port 54 of the valve body 22, into the upstream portion 50a of the bypass flow passage 50, through the opening 58, and into the downstream portion 50b of the bypass passage which also is the inlet portion 28a of the main flow passage 28, and then out of the first inlet 24 of the valve body 22. When the check valve 52 is in the closed position (as shown in FIG. 3), refrigerant flow is blocked through the opening 58. A pressure differential created by the compressor 16 in the system facilitates the advancing and retracting of the plunger 66. It is understood that other types of check valves could be used in place of the plunger-style check valve 52, such as a ball or cup style check valve, which may include a spring-biased ball. In some embodiments, the plunger-style check valve 52 may include a spring to hold the plunger 66 in the extended or retracted position. The in-line orientation of the check valve 52 allows the check valve to be hermetic to the system and decreases diameter of the adjusting gland and/or spring cavity of the adjustment mechanism 49. It is understood that the bypass arrangement, including location of the check valve 52 and/or configuration of the bypass flow passage 50, may be different in other embodiments, and may not include a hermetic seal internally of the system piping, as may be desirable for cost or other considerations.

[0036] Referring to FIGS. 6-8, other exemplary embodiments of TEVs 120, 220, 320 are shown. The TEVs 120, 220, 320 are substantially the same as the above-referenced TEV 20, and consequently the same reference numerals but respectively in the 100, 200 and 300-series are used to denote structures corresponding to similar structures in the TEVs. In addition, the foregoing description of the TEV 20 is equally applicable to the TEVs 120, 220, 320, except as noted below. In addition, it is understood that aspects of the TEVs 20, 120, 220, 320 may be substituted for one another or used in conjunction with one another where applicable.

[0037] The TEVs 120, 220, 320 have essentially the same arrangement of the flow passages and valving for expansion of the refrigerant in the forward flow expansion mode, but have different arrangements of their respective bypass passages and the locations of their respective bypass check valves. As such, similarly to the TEV 20, the TEVs 120, 220, 320 respectively include a valve body 122, 222, 322 having a first inlet 124, 224, 344; a first outlet 126, 226, 326; a first main flow passage 128, 228, 328 extending from the first inlet to the first outlet, a metering orifice 130, 230, (hidden in FIG. 8) in the first main flow passage between the first inlet and the first outlet, a valve member 131, 231, 331 movable in the valve body 122, 222, 322 relative to the metering orifice to control flow of operating fluid passing through the first main flow passage and across the metering orifice as the respective TEV is operating in a forward flow expansion mode to receive liquid from a condenser and to pass two-phase liquid to an evaporator. The TEVs 120, 220, 320 also respectively include a second inlet 132, 232, (not shown in FIG. 8); a second outlet 134, 234, (not shown in FIG. 8); and a second main flow passage 136, 236, 336 extending from the second inlet to the second outlet, in which the second main flow passage forms at least a portion of a suction line in the forward expansion mode which is separate from the first main flow passage. Also similarly to the TEV 20, the TEVs 120, 220, 320 respectively include a power element 140, 240, 340 which comprise an actuator, such as a flexible diaphragm 144, 244, 344, that is operatively coupled to the valve member 131, 231, 331. The power element 140, 240, 340 is configured to control movement of the valve member at least partially in response to changes in temperature and pressure of operating fluid passing through the second main flow passage 136, 236, 336 from the second inlet to the second outlet when the valve is operating in the forward flow expansion mode. In addition, similarly to TEV 20, the TEVs 120, 220, 320 respectively include a bypass flow passage 150, 250, 350 extending internally through the valve body 122, 222, 322 and bypassing the metering orifice 130, 230, (not shown in FIG. 8); and further include a check valve 152, 252, 352 arranged internally of the valve body in the bypass flow passage 150, 250, 350, in which the check valve is configured to activate at least partially in response to operating fluid flowing in a reverse flow bypass mode whereby the check valve 152, 252, 352 opens the bypass flow passage 150, 250, 350 to permit operating fluid to bypass the metering orifice in the reverse flow bypass mode.

[0038] Referring particularly to FIG. 6, instead of having the check valve arranged horizontally through a bore recessed in the inlet connection port as is the case with the TEV 20, the TEV 120 has its check valve 152 arranged vertically to be inserted through a bore 160 having an opening 162 in the second main flow passage 136. In the illustration, the check valve 152 is shown in its closed state to close the bypass flow passage 150. The bypass arrangement in the illustrated embodiment utilizes the connection port 154 at the first outlet 126 and the outlet portion 128b of the first main passage 128 is a shared passage with the upstream portion 150a of the bypass passage 150. In the reverse flow bypass mode, the bypass flow passes across the poppet portion of the valve member 131 to act against the plunger 166 of the check valve 152 to activate it to open. When the check valve 152 is opened, the bypass flow bypasses the metering orifice 130 and passes to the downstream portion 150b of the bypass passage 150. As shown, the downstream portion 150b of the bypass passage is a shared passage with the inlet portion 128a of the first main passage 128 and also shares the same connection port 156. In this manner, with the shared passages, the TEV 120 minimizes size. The TEV 120 also is hermetic to the system since any leakage past the check valve 152 is contained within the system. However, such leakage would permit leakage from the suction line of the second main passage 136 to the liquid line of the first main passage 128.

[0039] Referring to FIG. 7, the TEV 220 has its check valve 252 arranged vertically to be inserted through a bore 260 having an opening 262 in the bottom of the valve body 222. The bore 260 is plugged with a suitable plug 275 to prevent loss of refrigerant from the valve body 222. The check valve 252 in this arrangement includes a central passage 276 through plunger 266 that is plugged with a plug 277 in a closed state, and which permits communication through orifices 278 in the stationary plug 264 in the open state. In the illustration, the check valve 252 is shown in its open state to open the bypass flow passage 250. The bypass arrangement in the illustrated embodiment utilizes the connection port 254 at the first outlet 226 and an upstream portion 250a of the bypass passage 250 that branches off from the outlet portion 228b of the first main passage 228. When the check valve 252 is opened, the bypass flow bypasses the metering orifice 230 and passes to the downstream portion 250b of the bypass passage 250, which is a shared passage with the inlet portion 228a of the first main passage 228 and also shares the same connection port 256. In this manner, with the shared passages, the TEV 220 minimizes size. The introduction of the plug 275 into the bore 260 provides an additional possible leak path, but otherwise any leakage past the check valve 252 is contained to within the system. The passage 260 and plug 275 could be omitted if the diameter of the adjustment mechanism 249 were increased to allow the insertion of the check valve.

[0040] Referring to FIG. 8, the TEV 320 has its check valve 352 inserted through opening 362 into a bore 360 arranged at an angle through a sidewall of the valve body 322. In the illustration, the check valve 352 is shown in its closed state to close the bypass flow passage 350. The bypass arrangement in the illustrated embodiment utilizes the connection port at the first outlet (hidden from view) and the outlet portion of the first main passage 328 is a shared passage with the upstream portion of the bypass passage 350. In the reverse flow bypass mode, the bypass flow passes across the poppet portion of the valve member 331 to act against the plunger 366 of the check valve 352 to activate it to open. When the check valve 352 is opened, the bypass flow bypasses the metering orifice (hidden from view) and passes to the downstream portion 350b of the bypass passage 350. This downstream portion 350b of the bypass passage 350 opens into the inlet portion of the first main passage 328 and permits bypass flow to exit through the first inlet 324. The TEV 320 is not hermetic to the system since any leakage past the check valve 352 can escape to the external environment.

[0041] While exemplary forms of a TEV 20, 120, 220, 320 have been described above, it understood that alternative configurations also could be employed. For example, although the TEVs have been shown and described above as bulbless-style expansion valves, the TEV also could be a non-bulbless style TEV, such as one that uses a sensing bulb and capillary tube to sense the temperature in the suction line, as would be understood by those having ordinary skill in the art.

[0042] According to an aspect, a bulbless-style expansion valve includes: a valve body having a first inlet, a first outlet, a first main flow passage extending from the first inlet to the first outlet, a metering orifice in the first main flow passage between the first inlet and the first outlet, a second inlet, a second outlet, and a second main flow passage extending from the second inlet to the second outlet, the second main flow passage being separate from the first main flow passage; a valve member movable in the valve body relative to the metering orifice to control flow of operating fluid passing through the first main flow passage and across the metering orifice as operating fluid flows from the first inlet to the first outlet when the valve is operating in a forward flow expansion mode; a power element operatively coupled to the valve member and configured to control movement of the valve member at least partially in response to changes in temperature and pressure of operating fluid passing through the second main flow passage from the second inlet to the second outlet when the valve is operating in the forward flow expansion mode; a bypass flow passage extending internally through the valve body and bypassing the metering orifice; and a bypass check valve arranged internally of the valve body in the bypass flow passage, the bypass check valve being configured to activate at least partially in response to operating fluid flowing in a reverse flow bypass mode in which activation of the bypass check valve opens the bypass flow passage to permit operating fluid to bypass the metering orifice in the reverse flow bypass mode.

[0043] Exemplary embodiments may include one or more of the following additional features, separately or in any combination.

[0044] In exemplary embodiment(s), the check valve and bypass flow passage are arranged to provide hermetic sealing in which any leakage past the check valve does not escape to an external environment outside of the valve and/or system in which the valve is incorporated.

[0045] In exemplary embodiment(s), the bypass check valve is at least partially arranged in-line with the first main flow passage.

[0046] In exemplary embodiment(s), the first outlet of the first main flow passage and an inlet of the bypass flow passage share a common external connection port of the valve body which is configured to connect a conduit of a system incorporating the valve.

[0047] In exemplary embodiment(s), the first inlet of the first main flow passage and an outlet of the bypass flow passage share a common external connection port of the valve body which is configured to connect a conduit of a system incorporating the valve.

[0048] In exemplary embodiment(s), the first main flow passage includes an upstream portion this is upstream of the metering orifice when the valve is operating in the forward flow expansion mode.

[0049] In exemplary embodiment(s), the bypass flow passage includes a downstream portion that is downstream of a check valve seat that the bypass check valve engages when closed.

[0050] In exemplary embodiment(s), at least a portion of the upstream portion of the first main flow passage and at least a portion of the downstream portion of the bypass flow passage are a commonly shared passage in the valve body.

[0051] In exemplary embodiment(s), the first main flow passage includes a downstream portion this is downstream of the metering orifice when the valve is operating in the forward flow expansion mode.

[0052] In exemplary embodiment(s), the bypass flow passage includes an upstream portion that is upstream of a check valve seat that the bypass check valve engages when closed.

[0053] In exemplary embodiment(s), at least a portion of the downstream portion of the first main flow passage and at least a portion of the upstream portion of the bypass flow passage are a commonly shared passage in the valve body.

[0054] In exemplary embodiment(s), the bypass flow passage includes a first upstream portion that is shared with a portion of the downstream portion of the first main flow passage, and wherein the bypass flow passage includes a second upstream portion that branches off from the first main flow passage and extends internally within the valve body to the check valve seat.

[0055] In exemplary embodiment(s), the bypass check valve is inserted into a vertical bore having an opening in a bottom of the valve body, wherein at least part of the bore is plugged.

[0056] In exemplary embodiment(s), the bypass check valve is inserted into a vertical bore having an opening in the second main flow passage.

[0057] In exemplary embodiment(s), the bypass check valve is inserted into an inclined bore having an opening in a sidewall of the valve body.

[0058] In exemplary embodiment(s), the bypass check valve is inserted into a bore having an opening in a recessed portion of the common external connection port of the first inlet of the first main flow passage and the outlet of the bypass flow passage.

[0059] In exemplary embodiment(s), the first main flow passage includes a downstream portion this is downstream of the metering orifice when the valve is operating in the forward flow expansion mode, wherein the bypass flow passage includes an upstream portion that is upstream of a check valve seat that the bypass check valve engages when closed, and wherein the upstream portion of the bypass flow passage is fluidly separated from the downstream portion of the first main flow passage.

[0060] In exemplary embodiment(s), the bypass flow passage includes a through-opening in the valve body that is downstream of the check valve seat, the through-opening being configured to fluidly connect the upstream portion of the bypass flow passage to a downstream portion of the bypass flow passage when the bypass check valve is activated to open.

[0061] In exemplary embodiment(s), the downstream portion of the bypass flow passage is commonly shared with an upstream portion of the first main flow passage that is upstream of the metering orifice when the valve is operating in the forward flow expansion mode.

[0062] In exemplary embodiment(s), the bypass check valve is inserted into a bore having an opening in a recessed portion of a common external connection port of the first inlet of the first main flow passage and an outlet of the bypass flow passage.

[0063] In exemplary embodiment(s), the check valve comprises a stationary plug and a plunger that is movable relative to the plug.

[0064] In exemplary embodiment(s), the power element comprises a casing and a flexible diaphragm at least partially within the casing, the flexible diaphragm being operatively coupled to the valve member and being configured to flex at least partially in response to changes in temperature and pressure of operating fluid passing through the second main flow passage when the valve is operating in the forward flow expansion mode.

[0065] In exemplary embodiment(s), the metering orifice is formed as an adjustable flow restrictive opening in an annular region between a valve seat in the first main flow passage and an engagement portion of the valve member.

[0066] According to another aspect, a thermal expansion valve for a system, includes: a valve body having at least one inlet, at least one outlet, at least one main flow passage extending from the at least one inlet to the at least one outlet, and a metering orifice in the at least one main flow passage between the at least one inlet and the at least one outlet; a valve member movable in the valve body relative to the metering orifice to control flow of operating fluid passing through the at least one main flow passage and across the metering orifice as operating fluid flows from the at least one inlet to the first at least one when the valve is operating in a forward flow expansion mode; a power element comprising an actuator operatively coupled to the valve member and configured to control movement of the valve member; a bypass flow passage extending internally through the valve body and bypassing the metering orifice; and a bypass check valve arranged internally of the valve body in the bypass flow passage, the bypass check valve being configured to activate at least partially in response to operating fluid flowing in a reverse flow bypass mode in which activation of the bypass check valve opens the bypass flow passage to permit operating fluid to bypass the metering orifice in the reverse flow bypass mode; wherein the valve body includes an external inlet port configured to fluidly connect to a conduit of the system, and an external outlet port configured to fluidly connect to another conduit of the system, and wherein the bypass check valve is inserted into a bore in the valve body having an opening at the external inlet port or at the external outlet port.

[0067] According to another aspect, a bulbless valve includes: a valve body having a suction passage through which fluid flows from a heat exchanger to a compressor in a forward flow mode and from the compressor to the heat exchanger when the valve is operating in a reverse flow mode, and, the valve further defining a first opening and a second opening connected by a passage, and an orifice between the first opening and the second opening; a valve member driven by a power element to control the flow of fluid through the orifice; a check valve positioned in the passage and configured such that when the check valve is in an open position, fluid can flow from the second opening to the first opening, and when the valve is in the closed position fluid is blocked from the passage.

[0068] According to another aspect, a system includes: a first heat exchanger, a second heat exchanger, and the valve according to any of the foregoing features, which is located between first and second heat exchangers, wherein the valve is configured meter fluid flow from the first heat exchanger to the second heat exchanger in the forward flow expansion mode, wherein the valve is configured to bypass flow from the second heat exchanger to the first heat exchanger in a reverse flow bypass mode, and wherein the system does not have an external bypass line that bypasses the valve in the reverse flow bypass mode.

[0069] As used herein, an “operative connection,” or a connection by which entities are “operatively connected,” is one in which the entities are connected in such a way that the entities may perform as intended. An operative connection may be a direct connection or an indirect connection in which an intermediate entity or entities cooperate or otherwise are part of the connection or are in between the operatively connected entities. An operative connection or coupling may include the entities being integral and unitary with each other.

[0070] It is to be understood that terms such as “top,” “bottom,” “upper,” “lower,” “left,” “right,” “front,” “rear,” “forward,” “rearward,” and the like as used herein may refer to an arbitrary frame of reference, rather than to the ordinary gravitational frame of reference.

[0071] The phrase “and/or” should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified unless clearly indicated to the contrary. Thus, as a non-limiting example, a reference to “A and/or B,” when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A without B (optionally including elements other than B); in another embodiment, to B without A (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0072] The word “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” may refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.”

[0073] Although the principles, embodiments and operation of the present invention have been described in detail herein, this is not to be construed as being limited to the particular illustrative forms disclosed. They will thus become apparent to those skilled in the art that various modifications of the embodiments herein can be made without departing from the spirit or scope of the invention. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.