eTXV direct discharge injection compressor

Abstract

A thermal management system is provided that includes a vapor injection scroll compressor that can increase the heating capacity of a downstream passenger compartment condenser to meet increased heat demand. A compressor operable in a heat pump mode of a refrigerant circuit includes a compression space in which a refrigerant is compressed. The compression space includes a discharge port and an injection port. An exhaust chamber is fluidly connected to the compression space by the discharge port. An injection chamber is fluidly connected to the compression space by the injection port. A discharge recirculation path selectively provides fluid communication between the exhaust chamber and the injection chamber.

Description

[Technical field]

[0001] The present invention relates to an eTXV direct discharge injection compressor, and more particularly to a thermal management system including a vapor injection scroll compressor with discharge recirculation. [Background technology]

[0002] A thermal management system for use in an electric vehicle may utilize a heat pump system to manage the temperature of various components of the electric vehicle and / or to heat or cool air delivered to the passenger compartment of the vehicle. The heat pump system includes at least one compressor circulated by a refrigerant, a first heat exchanger acting as a condenser, an expander, and a second heat exchanger acting as an evaporator. The compressor of the system raises the temperature of the refrigerant to provide heat to a downstream condenser, thereby in heat exchange relationship with the air delivered to the passenger compartment. The heating capacity of the passenger compartment condenser is therefore dependent on the temperature of the refrigerant entering the passenger compartment condenser after compression in the compressor.

[0003] One disadvantage of such systems occurs when the thermal management system must increase the heating capacity of the refrigerant in the cabin condenser to meet heating demands, particularly at low ambient air temperatures. That is, low ambient air temperatures may extract enough heat from the refrigerant in the cabin condenser that the total heating capacity of the thermal management system may be undesirably reduced. Thus, it is necessary to provide additional heat to the refrigerant before it is introduced into the cabin condenser to account for such low temperature conditions.

[0004] A solution to the problem of increased heating demand in the cabin condenser includes the use of a vapor-injection scroll compressor to further heat the refrigerant upstream of the cabin condenser. Vapor-injection scroll compressors provide advantages over conventional scroll compressors by utilizing two different inputs of refrigerant, each having a different pressure and / or temperature. Scroll compressors typically include a fixed scroll that is stationary and an orbiting scroll that is configured to be contained within and orbit the fixed scroll. The orbiting motion of the orbiting scroll, as well as the similar helical shapes of the fixed and orbiting scrolls, continuously form a pair of substantially symmetrical compression chambers between the fixed and orbiting scrolls. Each of the compression chambers is typically symmetrical about a centralized discharge port of the vapor-injection scroll compressor. The refrigerant enters each of the pressure chambers through one or more inlet ports formed adjacent to the radially outermost portion of the fixed scroll, and the volume of each pressure chamber gradually decreases as the orbiting scroll orbits relative to the fixed scroll, and the pressure of the refrigerant disposed in each pressure chamber gradually increases as the refrigerant approaches the radially central discharge port.

[0005] Vapor injection scroll compressors are differentiated from conventional scroll compressors by injecting the returned refrigerant into each of the compression chambers located at intermediate positions radially between the inlet port located on the outside and the exhaust port located in the center of the fixed scroll. Thus, the injected refrigerant enters each of the pressure chambers located in that region of the fixed scroll repeatedly experiencing a pressure of the refrigerant flowing radially inwardly, which is generally intermediate between the suction pressure created at the inlet port of the fixed scroll and the discharge pressure created at the exhaust port. The injected refrigerant originates from the injection chambers of the vapor injection scroll compressor, which are configured to receive the returned refrigerant therein before re-entering the compression chambers.

[0006] Thus, the vapor injection scroll compressor can be utilized to increase the heating capacity of the refrigerant exiting the compression chamber by injecting refrigerant into the compression chamber at a pressure and temperature greater than the pressure and temperature of the refrigerant generated at the suction port of the vapor injection scroll compressor. The refrigerant exiting the vapor injection scroll compressor can thus be provided to the cabin condenser at a higher temperature than it would be if the vapor injection scroll compressor were operated without heated vapor in an intermediate position within the compressor chamber. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] US Patent Application Publication No. 2013 / 0025311 [Patent Document 2] US Patent Application Publication No. 2021 / 0285445 Summary of the Invention [Problem to be solved by the invention]

[0008] However, one disadvantage of using a vapor injection scroll compressor is the need to integrate additional components into the thermal management system to recirculate the refrigerant through the vapor injection scroll compressor at the appropriate temperature and pressure for re-injection into the compression chamber according to the selected mode of the thermal management system. Such systems typically include a bypass path branched off from a location downstream of the cabin condenser for return of the refrigerant while bypassing the remainder of the corresponding primary refrigerant circuit. Such a bypass path may also include an expander for adjusting the temperature and / or pressure of the refrigerant prior to injection into the compression chamber, and may optionally include an internal heat exchanger downstream of the expander for adding heat to the recirculated refrigerant from the refrigerant flowing along the primary refrigerant circuit after temperature reduction in the expander. The introduction of such additional components adds cost and complexity to the resulting thermal management system.

[0009] Another problem with the above-mentioned system relates to the manner in which the vapor injection scroll compressor still receives refrigerant that has already been exhausted to the ambient air in the cabin condenser due to the downstream placement of the fluid branch in the low path relative to the cabin condenser. Also, if an internal heat exchanger is used downstream of the expander, reheating of the refrigerant occurs similarly to the vented refrigerant flow already opening into the cabin condenser. The introduction of the vapor injection scroll compressor into the thermal management system therefore does not account for or address the problems posed, especially for low ambient temperatures, for the same reasons that are evident from the conventional thermal management system lacking vapor injection as described above. The pressure of the refrigerant must also be reliably low inside the expander located along the bypass path in case the refrigerant temperature drops significantly when it re-enters the compressor. The expansion of the refrigerant along the bypass path results in limited ability to add heat capacity to the cabin condenser through the use of the configuration.

[0010] Another method for adding heat to the air to be provided to the cabin can include integrating a heating device, such as an electrically powered positive temperature coefficient (PTC) heater, into the flow path of the air provided to the cabin, but the introduction of such a heating device adds cost and complexity to the thermal management system and requires the introduction of heating, ventilation, and air conditioning (HVAC) housing to contain the heating device in the proper location to properly heat the air. It would therefore be desirable to provide a thermal management system with a vapor injection scroll compressor that can increase the heating capacity of a downstream passenger compartment condenser to meet increased thermal demand. [Means for solving the problem]

[0011] Consistent with the present invention, it has surprisingly been discovered that a vapor injection scroll compressor with exhaust recirculation for increased heat capacity of the refrigerant circuit.

[0012] In accordance with the present invention, the compressor includes a compression space in which a refrigerant is compressed, the compression space including a discharge port and an injection port. An exhaust chamber is fluidly connected to the compression space by the discharge port. An injection chamber is fluidly connected to the compression space by the injection port. A discharge recirculation path selectively provides fluid communication between the exhaust chamber and the injection chamber.

[0013] A method of operating a compressor according to the present invention is also disclosed, the method including the steps of discharging a refrigerant from a compression space to a discharge chamber, the discharged refrigerant having a discharge pressure, placing the refrigerant disposed in the discharge chamber in fluid communication with an injection chamber, the refrigerant having an injection pressure while in the injection chamber, and injecting the refrigerant at the injection pressure into the compression space to increase the pressure and temperature of the refrigerant in the compression space. [Brief description of the drawings]

[0014] The above, as well as other objects and advantages of the present invention will become readily apparent to those of ordinary skill in the art from the following detailed description of the invention when considered in conjunction with the accompanying drawings. [Figure 1] 1 is a schematic flow diagram of a refrigerant circuit of a compressor having a discharge recirculation function of the present invention. [Diagram 2] FIG. 1 is a perspective view of a compressor with exhaust recirculation according to an embodiment of the invention. [Diagram 3] 3 is a cross-sectional view through the rear housing of the compressor taken from the perspective of section line 3-3 of FIG. 2. [Figure 4] 4 is a partial cross-sectional view through the rear housing of the compressor taken from the perspective of section line 4-4 of FIG. 2. [Diagram 5] 3 is a cross-sectional view through the rear housing of the compressor taken in terms of section line 5 of FIG. 2. [Figure 6]3 is a cross-sectional view through the rear housing of the compressor taken in terms of section line 6 of FIG. 2. [Figure 7] 3 is a perspective elevational view of the rear housing of the compressor of FIG. 2 with the cover plate removed to expose the sealing member. [Figure 8] FIG. 3 is a rear elevational view of the rear housing of the compressor of FIG. 2. [Figure 9] FIG. 4 is a cross-sectional view through a discharge recirculation path of a compressor according to another embodiment of the present invention. [Figure 10] FIG. 4 is a cross-sectional view through a discharge recirculation path of a compressor according to another embodiment of the present invention. [Figure 11] 4 is a schematic flow diagram of a refrigerant circuit having a compressor in which a discharge recirculation function is operated in conjunction with a recirculation bypass function according to another embodiment of the present invention. [Figure 12] 4 is a schematic flow diagram of a refrigerant circuit having a discharge recirculation function disposed outside a compressor according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The following detailed description and the accompanying drawings are intended to illustrate various embodiments of the present invention. The description and drawings are intended to enable one of ordinary skill in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner.

[0016] 1 illustrates a refrigerant circuit according to an embodiment of the present invention. The refrigerant circuit 10 forms part of a thermal management system of a vehicle. The vehicle may be an electric or hybrid vehicle that relies on stored electrical power to provide heat to various components of the vehicle as well as air provided to the passenger compartment of the vehicle through operation of the thermal management system and the refrigerant circuit 10.

[0017] The refrigerant circuit (10) includes at least a compressor (12), a first heat exchanger (13), an expander (14), and a second heat exchanger (15). The refrigerant circuit (10) illustrated in Figure 1 is simplified in nature and may include additional flow paths, valves, and / or components as shown without departing from the scope of the present invention, so long as the same relationships exist within the refrigerant circuit (10) to describe operation in the manner described below.

[0018] The refrigerant circuit (10) may be configured to operate in a heat pump mode of operation in which the refrigerant is compressed and heated in the compressor (12) before flowing to the first heat exchanger (13). When the refrigerant circuit is operable in a heat pump mode, the first heat exchanger (13) may be configured as a passenger compartment condenser and may be disposed in an HVAC air handling casing (not shown) of an associated vehicle for selective heat exchange relationship with air provided to the passenger compartment. The heated refrigerant gives up heat to air passing through the first heat exchanger (13), thereby heating the air and cooling and condensing the refrigerant. The cooled liquid refrigerant is then expanded in the expander (14) before being heated and then evaporated in the second heat exchanger (15), which acts as an evaporator for the refrigerant circuit (10) for the flow configuration described above, before returning as a gas at a relatively low temperature and pressure to the inlet side of the second heat exchanger (15) of the compressor (12).

[0019] Although not shown, the refrigerant circuit (10) may include various fluid lines and / or valves for defining a flow configuration through the refrigerant circuit (10) that is opposite to that described above in connection with heat pump mode operation. For example, the refrigerant circuit (10) may also be operable when the refrigerant flows generally counterclockwise (see FIG. 1) after exiting the compressor (12) through the use of appropriate valves and flow path arrangements adjacent the compressor (12), such that the refrigerant flows sequentially through the second heat exchanger (15), the expander (14), and the first heat exchanger (13). Such an opposite flow configuration results in the first heat exchanger (13) functioning as a cabin evaporator, where heat is transferred from the air to be provided to the cabin to the refrigerant within the first heat exchanger (13). Thus, the first heat exchanger (13) can operate as either a heating or cooling device depending on the flow sequence through the refrigerant circuit if such a bi-directional flow configuration is used as desired. An example of such a variable and / or bi-directional flow configuration is disclosed in U.S. Patent No. 5,399,633, the entire contents of which are incorporated herein by reference.

[0020] In other embodiments, the refrigerant circuit (10) may be absent such a counter-flow configuration, and instead, a second heat exchanger (15) may be integrated into the HVAC air handling casing to operate as a passenger compartment evaporator when the refrigerant circuit (10) is operable in the heat pump mode described above. That is, the second heat exchanger (15) may be disposed within such an HVAC air handling casing to selectively allow refrigerant to pass therethrough to cool the air provided to the passenger compartment based on the vehicle passenger's selection of an air conditioning mode of operation.

[0021] The refrigerant circuit 10 may be in heat exchange or fluid communication with additional components or systems of an associated vehicle to heat and / or cool the additional components or systems of the associated vehicle. For example, additional heat exchangers may be provided in fluid communication with the refrigerant of the refrigerant circuit 10, such as chillers for cooling the vehicle's battery, heat-generating electronic components of the vehicle, etc. Such chillers may be in fluid and / or heat exchange communication with one or more secondary cooling fluids associated with such secondary systems. In other situations, such heat exchangers may be provided to heat components that are in a cold primary state to enable the electronic components to operate most efficiently, or to potentially freeze or melt water or ice that has accumulated in the components.

[0022] In any case, the following description assumes that the refrigerant circuit (10) is operable in a heat pump mode with refrigerant flowing from the compressor (12) in the direction of the first heat exchanger (13), such that the first heat exchanger (13) can operate as a condenser to cool the refrigerant passing therethrough and heat any fluid passing therethrough, which may be air provided to the passenger compartment of the associated vehicle. It will be apparent to those skilled in the art that the following structures may be integrated into the refrigerant circuit (10) at any location between the side located downstream of the compressor (12) and the side located upstream of the first heat exchanger (13) without departing from the scope of the present invention, although a particular location and configuration may be preferred to reduce the number of components required to achieve the benefits of the refrigerant circuit (10) and compressor (12) and to restore the refrigerant to a desired pressure and temperature to take advantage of the disclosed thermal management system.

[0023] The compressor (12) includes a housing (20) that can be separated into a first housing (21) and a second housing (22), as shown in FIG. 1. In the embodiment shown, the first housing (21) can be traditionally named the "front housing" of the compressor (12), and the second housing (22) can be traditionally named the "rear housing" of the compressor. The front housing (21) can be disposed toward a first end through which the refrigerant first enters the compressor (12), which corresponds to the inlet end of the compressor (12), and the rear housing (22) can be disposed toward a second end of the housing (20) through which the refrigerant exits the compressor (12) after being compressed therein, which corresponds to the outlet end of the compressor (12). The front housing (21) and the rear housing (22) may each be provided as a substantially hollow skin defining an open space, and the housings 21 and 22 may be joined to one another along a circumferentially extending seam, the open space being defined by the cooperation of the housings 21 and 22 which accommodate the various components of the compressor.

[0024] The compressor (12) generally includes a suction chamber (31), a compression space (32), a discharge chamber (33), and a vapor injection chamber (34). The suction chamber (31) may be disposed in the front housing (21) and forms a space into which a relatively low-pressure, low-temperature gaseous refrigerant first flows into the housing (21) to be provided to the compression space (32). The compression space (32) refers to a space inside the housing (20), and the orbiting scroll (not shown) orbits with respect to the fixed scroll to repeatedly generate pairs of compression chambers (not shown) between the fixed scroll and the orbiting scroll inside the compression space (32). These compression chambers are repeatedly formed and develop radially inward from the radial outer portion of the compression chamber (32) toward the radial center of the compression space (32) while the orbiting scroll orbits with respect to the fixed scroll. The continuous radial development of the compression chambers causes the pressure of the refrigerant stored in each of the compression chambers to increase toward the radial center of the compression space (32). This progression also results in each location found within the compression space (32) being subjected to variable and substantially cyclical pressures as the compression chambers formed repeatedly pass through, while the pressure gradually increases as the volume of each compression chamber decreases.

[0025] The compression space (32) may include at least one inlet (35) in each compression chamber extending radially inwardly for allowing refrigerant to enter the compression space (32) at suction pressure and at least one discharge port (36) for discharging refrigerant from the compression space (32) at discharge pressure due to compression. Each inlet (35) may be provided as an opening formed in an outer peripheral wall of the fixed scroll or orbiting scroll to provide fluid communication between the suction chamber (31) and the compression space (32). The discharge port (36) may be provided as an opening in an axial end wall of the fixed scroll at or near the radial center of the fixed scroll to provide fluid communication between the compression space (32) and the discharge chamber (33), by way of example and not by way of limitation. The general construction and method of operation of a scroll compressor having such a compression space formed by an orbiting scroll moving relative to the fixed scroll is disclosed in commonly owned U.S. Patent No. 11,002,272 (Klotten et al.), the entire contents of which are incorporated herein by reference.

[0026] A discharge check valve 37 may be disposed at the discharge port 36 between the compression space 32 and the discharge chamber 33. The discharge check valve 37 is configured to open only when the pressure of the refrigerant at the discharge port 36 in the compression space 32 exceeds the pressure of the refrigerant in the discharge chamber 33 as well as the bias flowing through the discharge check valve 37. The discharge check valve 37 may be a reed valve that bends toward the discharge port 36 each time the compression chamber advances repeatedly toward the discharge port 36 and the pressure differential is reached as described above, such bending tending to open a passageway leading to the discharge port 36. However, alternative one-way check valve configurations may be utilized without departing from the scope of the present invention. The discharge check valve 37 prevents undesired backflow of refrigerant into the compression space 32 during the cyclical movement of the orbiting scroll relative to the fixed scroll.

[0027] The compression space (32) may further include a pair of injection ports (38) for selectively providing fluid communication between the compression space (32) and the steam injection chamber (34). By way of example and not limitation, each injection port (38) may be provided as an opening in the axial end wall of the fixed scroll midway between the inlet (35) and the exhaust port (36) in the radial direction of the fixed scroll. The manner in which the injection ports (38) communicate with the compression space (32) at a radially midway location between the inlet (35) and the exhaust port (36) is shown diagrammatically in FIG.

[0028] An injection check valve (39) may be disposed at each of the injection ports (38) between the compression space (32) and the vapor injection chamber (34). Each injection check valve (39) is configured to open only when the refrigerant pressure in the vapor injection chamber (34) exceeds the refrigerant pressure in the compression space (32) at the location of that injection port (38) as well as the bias admitted by the associated injection check valve (39). Each injection check valve (39) may be a reed valve that bends relative to that injection port (38) whenever the pressure and force differential described above is reached during the repeated progression of the compression chamber toward the injection port (36), such bending tending to open a passage through that injection port (38) to provide selective fluid communication between the vapor injection chamber (34) and a momentarily aligned one of the compression chambers formed in the compression space (32).

[0029] Each of the injection check valves 39 prevents undesired flow of refrigerant from the compression space 32 toward the vapor injection chamber 34 during circulating movement of the orbiting scroll relative to the fixed scroll. The injection check valves 39 also ensure that the refrigerant permitted to enter the compression space 32 from the vapor injection chamber 34 has a higher pressure than the refrigerant already in the compression space 32 in one of the compression chambers progressing radially inward, thereby allowing the pressure (and temperature) in that compression chamber to increase through the vapor injection process described above. The refrigerant entering the pressure chamber at the vapor injection chamber 34 is therefore at an intermediate injection pressure intermediate the instantaneous suction pressure and instantaneous discharge pressure of the compressor. The injection check valves 39 may be representative of a vapor injection double reed valve assembly operating in a vapor injection scroll compressor as disclosed in U.S. Patent No. 5,393,321, the entire contents of which are incorporated herein by reference. However, alternative one-way check valve constructions may be utilized, if desired, without departing from the scope of the present invention.

[0030] Discharge chamber 33 may have an oil separator 40 disposed therein for removing oil from the discharged refrigerant. The oil separator may be of any construction for removing such oil, and may include centrifugal or surface augmentation features for capturing oil exposed to oil separator 40. Any suitable oil separator 40 may be utilized without departing from the scope of the present invention.

[0031] As shown generally in Figure 1, at least a portion, if not all, of the exhaust chamber (33), vapor injection chamber (34), and compression space (32) may be defined or located within the rear housing (22) of the housing (20). The various different spaces may be defined at least in part by a combination of interior surfaces of the rear housing (22), surfaces of the fixed scroll, surfaces of the orbiting scroll, and surfaces forming an intermediate valve assembly, such as the illustrated check valves (37, 39). The front housing (21) may contain the suction chamber (31) as well as the components necessary to induce orbiting of the orbiting scroll relative to the fixed scroll.

[0032] The compressor (12) is distinguished from prior art vapor injection scroll compressors in that it incorporates a discharge recirculation path (50) formed within the housing (20) for fluidly connecting the discharge chamber (33) to the vapor injection chamber (34). The refrigerant disposed within the discharge chamber (33) is selectively communicated to the vapor injection chamber (34) through the discharge recirculation path (50) through the operation of a flow control valve (52) disposed therealong. The flow control valve (52) may be configured to provide a variable orifice through which the refrigerant may flow as it flows from the discharge chamber (33) to the vapor injection chamber (34), the flow area provided by the variable orifice determining the flow rate of the recirculated refrigerant flowing from the discharge chamber (33) to the vapor injection chamber (34) as well as modifying the temperature and pressure changes of the refrigerant passing through the flow control valve (52) depending on the degree of contraction and expansion of the flow area provided by the flow control valve (52) for the upstream and downstream segments of the discharge recirculation path (50).

[0033] Thus, the described discharge recirculation path 50 and flow control valve 52 allow the compressor 12 to be operable in a discharge recirculation mode of operation, such that refrigerant having a discharge pressure in the discharge chamber 33 can be fluidly connected to the vapor injection chamber 34 for injection into the compression space 32 at intermediate injection pressure through one of the injection check valves 39. The intermediate injection pressure can differ from the discharge pressure due to the pressure loss experienced by the refrigerant as it passes through the discharge recirculation path 50 and flow control valve 52. The intermediate injection pressure is thus maximized when the variable orifice through the flow control valve 52 is adjusted to maximize the flow area corresponding to the minimized pressure loss of the flow control valve 52. The refrigerant located at the intermediate injection pressure is injected into the compression space 32 and the corresponding compression chamber through one of the injection ports 38 at a pressure greater than the pressure momentarily placed in the compression chamber, which in certain circumstances can substantially correspond to the instantaneous suction pressure of the refrigerant during the initial formation of the compression chamber.

[0034] With the pressure into the compression chamber increased, the injection of refrigerant causes an increase in the total pressure of the refrigerant in the compression chamber, which directly corresponds to an increase in the temperature of the refrigerant contained within the compression chamber. This increased temperature of the refrigerant in the compression space (32) causes the refrigerant to be discharged to the discharge chamber (33) at a higher temperature than would occur if no recirculation of the refrigerant occurred through the injection process described above. This increased temperature discharge refrigerant can then be partially recirculated once again through the discharge recirculation path (50). Thus, the repetition of this process occurring at a given operating condition of the compressor (12) causes a gradual increase in the discharge refrigerant temperature with each cycle until a new recirculation discharge temperature is reached that is higher than the discharge temperature of the refrigerant when the compressor (12) is operating at the same settings but without the recirculation function. The discharge recirculation process thus causes the discharge refrigerant to exit the compressor (12) and reach the first heat exchanger (13) at a higher temperature than would occur if the recirculation process were absent, which causes an increase in the heating capacity of the first heat exchanger (13) during the discharge recirculation mode operation of the compressor (12).

[0035] Through experimentation with various compressors having the general configuration shown in FIG. 1, it has been discovered that the use of the disclosed exhaust recirculation feature results in the ability to significantly increase the refrigerant discharge temperature while maintaining a coefficient of performance (COP) greater than 1.0. For example, it has been discovered that, depending on the compressor configuration, it is possible to increase the compressor refrigerant discharge temperature by 30-70° C. while maintaining a COP greater than 1.0. It has also been discovered that this increase in temperature occurs with a reduction in the mass flow rate of refrigerant exiting the compressor of less than 10% compared to the mass flow rate associated with operating the compressor without the exhaust recirculation feature. The ability to increase the temperature of the exhaust refrigerant in response to passenger heating demands while having a COP greater than 1.0 means that it can be utilized in lieu of additional heating devices such as electrically driven PTC heaters that can be integrated into the vehicle's HVAC casing to further heat the air provided to the passenger compartment. Thus, the integration of the exhaust recirculation feature into the compressor 12 simplifies the thermal management system comprising the refrigerant circuit 10 and the compressor 12 by allowing the HVAC casing to be equipped with a minimized number of components.

[0036] The flow control valve 52 may be configured to be adjusted to a fully closed position to prevent flow from the exhaust chamber 33 to the vapor injection chamber 34 through the exhaust recirculation path 50. The flow control valve 52 may be further configured to be adjusted from the fully closed position to a fully open position to maximize the flow area through the exhaust recirculation path 50. The flow control valve 52 may also be configured to be adjusted to a number of intermediate positions corresponding to different flow areas through the exhaust recirculation path 50 between the fully closed and fully open positions, each of which may correspond to a different flow rate of the refrigerant through the flow control valve 52 as well as other changes in pressure and temperature of the recirculated refrigerant. However, in other alternative embodiments, the flow control valve 52 may not include an adjustable flow function and instead may be configured to only be adjustable between an open position to allow the exhaust recirculation process and a closed position to prevent the process, if desired.

[0037] Adjustment of the flow control valve (52) may be determined by various factors associated with the operation of the compressor (12) and / or the remainder of the refrigerant circuit (10). In certain circumstances, the flow control valve (52) may be controlled in a desired configuration corresponding to a prescribed flow of refrigerant through the recirculation path (5), and such control may be based on a selected mode of operation or on conditions measured within the compressor (12) or by the remainder of the refrigerant circuit (10). For example, temperature sensors may be positioned along the refrigerant circuit (10) at desired locations to monitor the refrigerant at relevant locations, such as immediately upstream of the first heat exchanger (13), immediately downstream of the first heat exchanger (13), or combinations of the above among other possible locations, in the discharge chamber (33) for monitoring the refrigerant temperature in relation to the heating capacity of the refrigerant.

[0038] The flow control valve 52 may be opened only when the recirculation function described above is necessary to meet the heating demand of the refrigerant circuit 10, such as when the first heat exchanger 13 senses that the temperature of the refrigerant at one or more of the aforementioned locations is lower than the level required to heat the air provided to the cabin, which may occur if the first heat exchanger 13 is exposed to an especially low ambient air temperature. The flow control valve 52 may alternatively be controlled based on the measured temperature of the air provided to the cabin, and the recirculation function may be activated when the temperature of the air provided to the cabin is not heated according to a passenger selected setting. The flow control valve 52 may also be controlled based on a combination of such factors, if desired.

[0039] The flow control valve (52) can be adjusted to be fully open when a maximum flow rate of refrigerant from the discharge chamber (33) to the vapor injection chamber (34) is required, which corresponds to a minimized decrease in temperature and pressure of the recirculated refrigerant as it passes through the flow control valve (52). This maximum pressure and temperature of the refrigerant in the vapor injection chamber (34) corresponds to the maximum increase in pressure and temperature of the refrigerant momentarily disposed within the pressure space (32) when vapor is injected into the pressure space (32), which in turn corresponds to the maximum increase in pressure and temperature of the discharged refrigerant leaving the compression space (32) through the discharge port (36).

[0040] The fully open position of the flow control valve 52 can thus accommodate situations where a particularly high heating demand falls on the refrigerant circuit 10, such as when the refrigerant is in heat exchange with the ambient temperature at a particularly low temperature in the cabin condenser 13. The flow control valve 52 can be adjusted to one of several intermediate positions corresponding to intermediate positions between the fully closed position and the fully open position in order to meet a desired or specified heating demand of the refrigerant circuit 10.

[0041] The flow control valve 52 may be configured to be closed or to move toward an initially closed position when the temperature of the refrigerant exceeds a preselected value associated with potential damage to or inefficient operation of the compressor 12 and / or other components disposed along the refrigerant circuit 10. The flow control valve 52 may be configured to interrupt the recirculation function of the compressor 12 when the temperature of the refrigerant at selected locations along the refrigerant circuit 10, including that contained within the compressor 12, exceeds one of accommodated preselected temperature values ​​associated with the various components disposed along the refrigerant circuit 10.

[0042] The flow control valve (52) may also be adjusted to a fully open position when recirculation of exhaust refrigerant to the vapor injection chamber (34) is not required, such as when the heating demand placed on the refrigerant circuit (10) is low while the heat pump mode described above is operated, or when the refrigerant circuit (10) is operating in an alternative mode of operation where the temperature of the refrigerant downstream of the compressor (12) does not need to be regulated particularly high, such as when the refrigerant circuit (10) is operated to cool the air provided to the passenger compartment of the vehicle or other heat-generating components.

[0043] As shown in Figures 2 to 8, an embodiment of the compressor of Figure 1 is illustrated according to a first embodiment of the present invention. The compressor (12) includes a temperature dependent form of flow control valve (52) for passively limiting the temperature of the refrigerant discharged from the compressor (12). Figures 3 to 8 illustrate only the rear housing (22) of the compressor (20) without the front housing (21) and various components associated with the operation of the compressor (12) to better illustrate the function of the flow control valve (52) and discharge recirculation path (50) located exclusively within the rear housing (22) of the present invention. It should be understood that the components omitted in Figures 3 to 8 operate relative to the components illustrated in the manner described by Figure 1, and therefore detailed drawings and explanations are not required.

[0044] The rear housing (22) is shown to include a discharge chamber (33) divided into a first portion (33a) and a second portion (33b). The first portion (33a) is disposed immediately downstream of the discharge port (not shown in FIGS. 3-8) and the second portion (33b) is disposed downstream of the first portion (33a) and extends away from the first portion (33a). A flow opening (33c) fluidly connects the first portion (33a) to the second portion (33b). The second portion (33b) is shown as a cylindrical conduit extending at least partially radially outward relative to the location of a corresponding discharge port (36) of the compressor (12). The second portion (33b) can be formed into a bore that is inserted externally into the rear housing (22) if desired. An end of the second portion (33b) opposite the first portion (33a) is configured to be coupled to an external fluid line, component, etc., for communication with the refrigerant downstream of the compressor (12). For example, the second portion (33b) can be fluidly coupled to a fluid line leading to the first heat exchanger (13).

[0045] Although not shown in Figures 3-8, the oil separator (40) described above may be located in the discharge chamber (33) at the illustrated flow opening (33c) or immediately downstream of the flow opening (33c) or upstream of the discharge recirculation path (50) to ensure that oil is removed from the discharge refrigerant before it enters the discharge recirculation path (50). The oil separator (40) may be an oil ring embedded in the cylindrical structure of the second portion (33b) of the discharge chamber (33). However, the oil separator (40) may be located anywhere in the discharge chamber (33), including downstream of the discharge recirculation path (50), without departing from the scope of the present invention, and may include any structure or configuration suitable for separating oil from the refrigerant.

[0046] The rear housing 22 is also shown to include a vapor injection chamber 34 that is divided into a first portion 34a and a second portion 34b. The first portion 34a can be located immediately adjacent and upstream of the injection check valve 39, and the second portion 34b can be located upstream of and extending away from the first portion 34a. The flow direction referred to above means that the refrigerant flows from the discharge chamber 33 through the discharge recirculation path 50 toward the vapor injection chamber 34. A flow opening 34c fluidly connects the first portion 34a to the second portion 34b. The second portion 34b is shown to be a cylindrical conduit that extends radially outwardly at least partially relative to the location of the discharge port 36 of the compressor 12. If desired, the second portion 34b can be formed into a bore that is inserted externally into the rear housing 22. The end of second portion 34b opposite first portion 33a is shown configured to be coupled to an external fluid line, component, etc., to communicate refrigerant to compressor 12 for entry into vapor injection chamber 34. However, as shown in Figure 3, such end of second portion 34b may be capped to fluidly isolate second portion 34b from external fluid communication through said end, corresponding to the flow configuration of the vapor injection chamber relative to exhaust recirculation path 50 shown in Figure 1. As will be described below, second portion 34b may alternatively not be capped to allow the entry of another refrigerant stream entering compressor 12 for use in the vapor injection process through connection of second portion 34b to an external component.

[0047] The second portion (33b) of the exhaust chamber (33) and the second portion (34b) of the steam injection chamber (34) may be formed within the rear housing (22) such that they are angularly displaced from one another by less than 90 degrees due to a direct and shortened extension of the exhaust recirculation path (50) between the two sides. The exhaust recirculation path (50) may be formed within a bridge portion (80) of the rear housing (22) extending laterally between the radially extending portions of the rear housing (22) that define the cylindrical portions (33a, 34a) of the respective chambers (33, 34).

[0048] The guide opening (82) extends from the exterior surface of the rear housing (22) into the interior of the rear housing (22) and crosses and passes through the second portion (33b) of the discharge chamber (33) before extending into the interior of the connecting bridge portion (80) and being interrupted therein. The guide opening (82) may be a cylindrical bore formed in the interior of the rear housing (22) and introduced from the outside. The discharge recirculation path (50) includes a first flow segment (61), a first flow space (62), a tapered orifice (63), a second flow space (64), and a second flow segment (65) in the flow direction of the refrigerant flowing from the injection chamber (33) to the vapor injection chamber (34). The first flow segment (61) forms an inlet port into the discharge recirculation path (50) and extends laterally from the second portion (33b) of the discharge chamber (33) before crossing the first flow space (62). The first flow space (62) includes an L-shape such that the downstream portion of the first flow space (62) extends around the guide opening (82) and is axially aligned with the guide opening (82). The irregular shape of the first flow space (62) allows the refrigerant velocity to be reduced before it passes through the orifice (63), thereby reducing pressure loss in the passage through the orifice (63). The orifice (63) is provided at an end segment of the guide opening (82) that extends axially from between the first flow space (62) and the second flow space (64). The second flow space (64) extends laterally away from the guide opening (82) before intersecting with the second flow segment (65). The second flow segment (65) extends longitudinally toward and intersects with the second portion (34b) of the steam injection chamber (34) to form an exhaust port of the exhaust recirculation path (50). The second flow segment (65) may be formed in the form of a cylindrical bore introduced from the outside in a manner similar to the guide opening (82), and a portion of the rear housing (22) having a bore leading into the interior of the rear housing (22) may then be capped.

[0049] The illustrated exhaust recirculation path (50) may be defined between the indented exterior surface of the bridge portion (80) of the rear housing (22), and the opposing surface of the cover plate (90) may be coupled to the bridge portion (80) above the exhaust recirculation path (50). The cover plate (90) may be coupled to the rear housing (22) by way of example, but not by way of limitation, a threaded fastener. As shown in Figures 4 and 5, a sealing element may be disposed between the exterior surface of the bridge portion (80) and the opposing surface of the cover plate (90), and the sealing element (92) may be configured to extend around the periphery of the flow space (61, 62, 63, 64, 65) defined by the indented exterior surface of the bridge portion (80). The sealing element (92) provides a fluid-tight seal for the exhaust recirculation path (50) between the bridge portion (80) and the cover plate (90).

[0050] The use of various externally introduced bores and indentations in the rear housing 22 in forming the exhaust recirculation path 50 and related features allows for ease in manufacturability of the compressor. Such features also allow for easy repair or replacement in the event of damage or failure of the features.

[0051] The flow control valve (52) includes a flow control member (55) and a temperature dependent member (56). In the illustrated embodiment, the flow control member (55) is a cylindrical rod that is axially slidably received within the guide opening (82). The flow control member (55) extends through the second portion (33b) of the discharge chamber (33) into the bridge portion (80) of the rear housing (22). The flow control member (55) may include a large diameter (cylindrical) portion (57) that is sized to slidably engage and fit within the guide opening (82), a small diameter portion (58) formed at the distal end of the flow control member (55) that extends within the flow spaces (62, 63), and a tapered frusto-conical portion (59) for connecting the large diameter portion (57) to the small diameter portion (58).

[0052] The temperature dependent member 56 is disposed along an exterior surface of the rear housing 22 and defines a communication space 84. The communication space 84 is in fluid communication with the second portion 33b of the exhaust chamber 33 through a portion of the guide opening 82 that surrounds the flow control member 55. The temperature dependent member 56 includes a heat activated spring (not shown) that engages a diaphragm (not shown) that is coupled to a proximate end of the flow control member 55. The heat activated spring is configured to apply an increasing axial force to the diaphragm and associated flow control member 55 when exposed to an increasing temperature. The heat activated spring is responsive to the temperature of the exhaust coolant in the second portion 33b of the exhaust chamber 33 by exposing the temperature dependent member 56 to the coolant in the communication space 84. The increasing temperature of the exiting refrigerant thereby corresponds to the flow control member (55) entering the bridge portion (80) of the rear housing (22) with the larger diameter portion (57) approaching the orifice (63).

[0053] The flow area through the flow control valve (52) is determined by the axial position of the flow control element (55) relative to the orifice (63). As can be seen in Figures 3 and 4, continued axial advancement of the flow control member (55) first involves the entry of the smaller diameter portion (58) of the flow control member (55) into the orifice (63) and a reduction in the flow area of ​​the smaller diameter portion (58) before the frusto-conical portion (59) subsequently enters the orifice (63) and progressively further reduces the flow area. The orifice (63), and therefore the exhaust recirculation path (50), is closed when the larger diameter portion (57) is received within the orifice (63) or, alternatively, when the end of the frusto-conical portion (59) is seated against the surface defining the orifice (63).

[0054] Thus, the previously described temperature dependent flow control valve (52) may allow maximum flow through the discharge recirculation path (50) for temperatures below a first critical value and may begin to variably reduce the flow area to reduce the flow rate through the discharge recirculation path (50) for a temperature range between the first critical value and a second critical value greater than the first critical value. The flow control valve (52) may completely close the discharge recirculation path (50) upon reaching the second critical temperature, which may correspond to a maximum allowable safe temperature associated with the operation of the compressor (12) and / or any components associated with the refrigerant circuit (10).

[0055] Additionally, the illustrated flow control valve 52 may be configured to include a shutoff function associated with the control system of the refrigerant circuit 10. Such shutoff function may be electronically controlled by a control scheme of the control system, which may include sensing any of the conditions of the compressor 12 and / or the refrigerant circuit 10 as described above. For example, the flow control member 55 may be mechanically coupled to a solenoid-based actuator configured to advance the flow control member 55 toward a closed position when it generates a control signal indicating to an associated controller that the recirculation function is not required. Alternatively, a secondary valve member (not shown) may be utilized to open or close the exhaust recirculation path 50 at a location spaced apart from the illustrated orifice 63 and the flow control member 55, to provide an adjustable member configured to selectively extend across the second flow segment 65 in response to the generated control signal. Again, a solenoid or similar electrically adjustable, electronically controllable function may be used to control the position of such a secondary valve member.

[0056] 9 and 10, another embodiment of a discharge recirculation path (50) and associated flow control valve (52) according to another embodiment of the present invention is disclosed, assuming that the remaining portions of the compressor (12) are the same and operate in the same manner as disclosed in FIG. 1 or 2-8. The discharge recirculation path (50) includes a first flow space (62) acting as an inlet into the path (50) from the second portion (33b) of the discharge chamber (33) and a second flow space (65) acting as an outlet from the path (50) toward the second portion (34b) of the steam injection chamber (34). The flow control valve (52) is implemented as a ball valve forming a variable orifice (63) intermediate adjacent flow spaces (62, 64). The ball valve includes a rotatable ball member coupled to a rotor of an actuator. The actuator can be an electrically adjustable, electronically controllable rotary actuator configured to rotate a ball member relative to the flow spaces (62, 64). The ball member includes a flow passageway that includes a variable overlap with each of the flow spaces (62, 64) depending on the rotational position of the ball member corresponding to the formation of a variable orifice (63). The actuator may be configured to adjust the ball member to a number of intermediate positions including a fully closed position where there is no overlap between the flow spaces (62, 64) and the flow passageway passing through the ball member, and therefore no flow area, a fully open position where there is maximum overlap and flow area between the flow passageway and the flow spaces (62, 64) depending on the alignment of the flow spaces and the flow passageway, and intermediate flow areas based on the variable overlap between the flow passageway and the flow spaces (62, 64).

[0057] The flow control valve (52) of Figures 9 and 10 may be operated by any of the control schemes described above. For example, the flow control valve (52) may only be open to flow through the exhaust recirculation path (50) when a recirculation function is required to obtain a desired heat capacity of the first heat exchanger (13), and may additionally be closed during the recirculation process when the temperature of the exhaust refrigerant exceeds a critical value associated with potential damage to the compressor (12) and / or other components of the refrigerant circuit (10). Versions of the flow control valve (52) that are only electronically controlled may include a passive shutoff function, such that decisions regarding adjustment of the flow control valve (52) may be based on sensed conditions as described above for the refrigerant circuit (10) and / or the air being delivered to the passenger compartment of the vehicle.

[0058] It will be appreciated that other configurations of exhaust recirculation path (50) do not depart from the scope of the present invention and may be provided within rear housing (22) for use with other adjustable flow control valves (52) so long as the same fundamental relationships described herein are maintained. Thus, the disclosed mechanisms utilized to create a variable orifice through the exhaust recirculation path are not limited to the general configuration of compressor (12) illustrated in Figure 1. Flow control valve (52) may represent alternative expansion valve configurations while remaining within the scope of the present invention.

[0059] As shown in Fig. 11, a refrigerant circuit (110) according to another embodiment of the present invention is disclosed. The refrigerant circuit (110) is similar to the refrigerant circuit (10) and includes a compressor (12), a first heat exchanger (13), an expander (14) and a second heat exchanger (15), hereinafter referred to as forming the primary loop of the refrigerant circuit (110). However, the refrigerant circuit (110) further includes a bypass feature similar to that typically found in refrigerant circuits operating in prior art vapor injection scroll compressors (absent the presently disclosed exhaust recirculation feature) along with a bypass intercooler. The bypass feature is presented as a bypass path (150) extending from a location in the compressor (12) downstream of the first heat exchanger (13) according to the primary loop of the refrigerant circuit (10) to a vapor injection chamber (34) located upstream of the expander (14).

[0060] The bypass path (150) includes an expander (152) and an intercooler (154) disposed downstream thereof. The intercooler (154) is also disposed along the primary loop of the refrigerant circuit (110) at a branch intermediate between the bypass path (150) and the expander (14). Thus, the intercooler (154) is in heat exchange communication with each of the refrigerant flowing through the bypass path (150) and the refrigerant flowing through the primary loop of the refrigerant circuit (110) downstream of the branch of the bypass path (150). The expander (152) may be adjusted to include a variable flow area through the expander (152) to define a desired pressure drop of the refrigerant as it passes through the expander (152), thereby allowing the refrigerant passing through the expander (152) to expand from a relatively high temperature liquid state to a relatively low temperature and low pressure gas state for introduction into the compressor (12). If desired, the expander (152) may alternatively represent a fixed metering orifice used in conjunction with a shutoff valve to prevent unwanted flow through the bypass path (150).

[0061] The refrigerant passing through the bypass path (150) is expanded in the expander (152) before passing through the intercooler (154). The expansion of the bypassed refrigerant causes the refrigerant to travel along the bypass path to enter the intercooler (154) at a lower temperature than the refrigerant entering the intercooler (154) along the primary loop of the refrigerant circuit (110). Thus, the bypassed gaseous refrigerant is heated in the intercooler (154) while the primary loop is cooled in the intercooler (154).

[0062] The bypassed refrigerant arriving at the vapor injection chamber (34) is at an intermediate discharge pressure between the instantaneous suction pressure and the instantaneous discharge pressure of the compressor (12). When injected into the compression space (32), the intermediate injection pressure still exceeds the pressure instantaneously found in said compression chamber, and therefore the refrigerant at the intermediate injection pressure can still increase the discharge temperature of the refrigerant, albeit to a much lesser extent, in a manner similar to that described above with reference to the discharge recirculation function of the compressor (12). Thus, the operation of the refrigerant circuit (110) including the injection of the bypassed refrigerant into the compressor (12) helps to increase the discharge temperature of the refrigerant in the compressor (12) and thus the discharge pressure of the refrigerant in the compressor (12), which in turn helps to increase the refrigerant temperature of the first heat exchanger (13) arranged downstream. The injection of the bypassed refrigerant can therefore increase the heating capacity of the first heat exchanger compared to the operation of the refrigerant circuit (110) without the injection process.

[0063] The cooling of refrigerant through the primary loop of the refrigerant circuit (110) that occurs within the intercooler (154) also tends to result in an increased cooling capacity of the second heat exchanger (15), as compared to operation of the refrigerant circuit (110) without the bypass of refrigerant through the bypass path (150). If the second heat exchanger (15) is positioned as a passenger compartment evaporator for the refrigerant circuit (110), this increased cooling capacity can be used to cool heat-generating components in heat exchange relationship with the refrigerant circuit (110) or to aid in the cooling of the air provided to the passenger compartment.

[0064] 11, the compressor (12) still includes a discharge recirculation path (50) for fluidly coupling the discharge chamber (33) to the vapor injection chamber (34). The vapor injection chamber (34) is thus placed in selective fluid communication with each of the bypass path (15) through opening of the expander (152) (or the shutoff valve, if a fixed orifice is utilized) and the discharge chamber (33) through opening of the flow control valve (52).

[0065] The configuration of Figure 11 can be utilized to handle a variety of different operating modes of the compressor (12) and refrigerant circuit (110). For example, the bypass injection function associated with the bypass path (150) can be utilized when an increase in the cooling capacity of the second heat exchanger (15) is required, or when a relatively low increase in the heating capacity of the first heat exchanger (13) is required that is lower than that possible through the use of the exhaust recirculation function. The exhaust recirculation function associated with the exhaust recirculation path (50) can be utilized when the bypass injection function is unable to provide the desired heating capacity to the first heat exchanger (13). The disclosed refrigerant circuit (110) thus allows for both the heating and cooling effects of the refrigerant circuit (100) to be improved through the use of a compressor (12) with dual vapor injection capabilities.

[0066] The flow control valve (52) and expander (152) can be modulated to alternate the source of refrigerant entering the vapor injection chamber (34) depending on the selected mode of operation of the compressor (12) and / or refrigerant circuit (110). It is also contemplated that situations may exist where the vapor injection chamber (34) is in fluid communication with refrigerant originating from both paths 10 and 150, such that refrigerant from the exhaust recirculation path (50) is utilized to supplement the flow through the bypass path (150) when it is desirable to further increase the heating capacity of the first heat exchanger (15) while maintaining the increased cooling capacity of the second heat exchanger (15), even though such increased cooling capacity may be limited by the overall increase in temperature imparted by the recirculation process. For example, while maintaining a heat exchange relationship with the intercooler (154), the flow control valve (52) can be adjusted so that the refrigerant originating from the exhaust recirculation path (50) has a higher pressure than the refrigerant originating from the bypass path (150), so that despite the imparted temperature rise to the refrigerant exiting the compressor (12), the refrigerant flowing toward the second heat exchanger (15) is cooled sufficiently to enhance cooling capacity.

[0067] With reference to the embodiment of compressor 12 shown in Figure 3, second portion 34b of vapor injection chamber 34 may be provided without a cap as shown to allow the exposed end of second portion 34b to be fluidly coupled to an external fluid line or component, such as bypass path 15 as shown in Figure 11. Similarly, the embodiment of compressor 12 shown in Figures 9 and 10 may include the ability to fluidly connect through the end of second portion 34b of vapor injection chamber 34 as shown. However, it will be apparent that the disclosed flow configurations may be embodied through other structural relationships without departing from the scope of the present invention.

[0068] 12, a refrigerant circuit (210) according to another embodiment of the present invention is disclosed. The refrigerant circuit (210) is substantially the same as the refrigerant circuit (10), except for the removal of the discharge recirculation path (50) and corresponding flow control valve (52) from its location within the housing (20) of the compressor (12). Instead, the discharge recirculation path (50) is provided in an external fluid line that extends along the refrigerant circuit (210) to the vapor injection chamber (34) of the compressor (12) at a location between the compressor (12) and the first heat exchanger (13). Here, the external fluid line (60) includes a flow control valve (52) disposed along the external fluid line (60). In one example, the external fluid line (60) can be coupled to an end of the second portion (34b) of the vapor injection chamber (34) in the same manner as described above for the bypass path (150), but is not limited thereto. The external fluid line (60) with flow control valve (52) as the discharge recirculation path (50) still allows for an increase in the discharge temperature of the refrigerant, but does not realize the advantages discussed above in its ability to form a short, direct path within the housing (20) in the absence of any intervening components and fluid connections. The external fluid line (60), if necessary, can alternatively be an additional fluid line leading away from the compressor in addition to the fluid line leading towards the first heat exchanger (13), although the configuration described below undesirably requires an additional fluid connection to the rear housing (22) of the compressor (12) for communication with the discharge chamber (33).

[0069] The compressor (12) configuration disclosed in the present invention can be advantageously integrated into existing systems in the manner that the introduction of the exhaust recirculation path (50) and flow control valve (52) typically requires only modification of the rear housing (22) of an existing compressor (12) having the configuration of Figure 1 for implementing the injection process. The rear housing (22) configuration disclosed in Figures 3-10 can also be modified for use in any of the other circuits shown in Figures 1, 11 and 12, depending on the circumstances and by the inclusion of a vapor injection chamber (34) having the ability to be externally fluidly coupled to a different component or alternatively capped.

[0070] From the above description, a person having ordinary skill in the art to which the invention pertains can easily understand the essential features of the present invention without departing from the spirit and scope of the present invention, and can apply various modifications to make the present invention applicable to various uses and conditions. [Explanation of symbols]

[0071] 10 Refrigerant circuit 12 Compressor 13 1st heat exchanger 14 Expander 15 Second heat exchanger 20. Housing 21 1st Housing 22 Second Housing 31 Inhalation Chamber 32 Compressed Space 33 Exhaust chamber 33a Part 1 33b Part 2 33c flow opening 34 Steam injection chamber 34a Part 1 34b Part 2 34c flow opening 35 Inlet / Outlet port 36 Exhaust port 37 Discharge check valve 38 Injection port 39 Injection check valve 40 Oil Separator 50 Exhaust recirculation route 52 Flow Control Valve 55 Flow control components 56 Temperature-dependent components 57 Large diameter (cylindrical) part 58 Small diameter part 59 truncated conical part 60 External Fluid Line 61 First flow segment Flow space 62 First Fluid Space Fluid Space 63 Orifice Flow Space 64 Second Fluid Space Fluid Space 65 Second flow segment Flow space 80 Bridge section 82 Guide opening 84 Communication space 90 Cover Plate 92 Sealing material 100 Refrigerant circuit Refrigerant circuit 110 Refrigerant circuit 150 Bypass Route 152 Expander 154 Intercooler 210 Refrigerant circuit

Claims

1. a compression space including a discharge port and an injection port, in which the refrigerant is compressed; a discharge chamber communicating with the compression space by the discharge port; an injection chamber communicating with the compression space by the injection port; and a discharge recirculation path selectively providing fluid communication between the discharge chamber and the injection chamber.

2. The compressor of claim 1 , further comprising a flow control valve disposed along said exhaust recirculation path to provide said fluid communication between said exhaust chamber and said injection chamber.

3. 3. The compressor of claim 2, wherein the flow control valve is an adjustable expander.

4. 4. The compressor according to claim 3, wherein the flow control valve is adjustable to a fully closed position, a fully open position, and a plurality of intermediate positions.

5. 4. The compressor of claim 3, wherein said flow control valve is passively adjustable according to the temperature of the refrigerant in said discharge chamber.

6. 6. The compressor of claim 5, wherein the flow control valve further includes an electronically controlled shutoff feature to prevent fluid communication between the exhaust chamber and the injection chamber.

7. 4. The compressor of claim 3, wherein said flow control valve is electronically controlled.

8. 3. The compressor of claim 2, wherein the flow control valve is configured to prevent fluid communication between the discharge chamber and the injection chamber when the temperature of the refrigerant exceeds a critical value.

9. 2. The compressor according to claim 1, wherein the refrigerant is compressed from a suction pressure to a discharge pressure in the compression space, the refrigerant at the discharge pressure enters the discharge chamber through the discharge port, and the refrigerant is reduced in pressure from the discharge pressure to an injection pressure that is an intermediate between the suction pressure and the discharge pressure when passing through the discharge recirculation path, and the refrigerant at the injection pressure is selectively communicated to the compression space through the injection port.

10. 10. The compressor according to claim 9, wherein the injection of the refrigerant at the injection pressure into the compression space causes a temperature rise of the refrigerant at the discharge port.

11. 2. The compressor according to claim 1, wherein the compression space, the discharge chamber, the injection chamber, and the discharge recirculation path are all disposed within a housing of the compressor.

12. 12. The compressor according to claim 11, wherein the housing is divided into a front housing and a rear housing, and the compression space, the exhaust chamber, the injection chamber, and the exhaust recirculation path are all disposed within the rear housing.

13. 2. The compressor of claim 1, wherein the compression space, the exhaust chamber, and the injection chamber are all disposed in a housing of the compressor, the exhaust recirculation path is a fluid line connecting the exhaust chamber to the injection chamber, and at least a portion of the fluid line extends outside the housing.

14. 2. A refrigerant circuit including a compressor as described in claim 1, further comprising a condenser, a first expander, and an evaporator along a primary loop of the first expander, and the refrigerant circuit further comprises a bypass path extending to the injection chamber of the compressor along the primary loop at a position between the condenser and the expander.

15. 15. The refrigerant circuit according to claim 14, wherein the bypass path includes a second expander and an intercooler, the intercooler being in a heat exchange relationship with each of the refrigerant passing through the bypass path and the refrigerant passing through the primary loop upstream of the expander.

16. Discharging refrigerant from the compression space into a discharge chamber, the discharged refrigerant having a discharge pressure; placing the refrigerant disposed within the discharge chamber in fluid communication with an ejection chamber, the refrigerant having an ejection pressure when in the ejection chamber; injecting said refrigerant at said injection pressure into said compression space to increase the pressure and temperature of the refrigerant in said compression space.

17. 17. The method of claim 16, wherein the compression space, the discharge chamber, and the jet chamber are all disposed in a housing of the compressor, and the refrigerant is fluidly connected from the discharge chamber to the jet chamber through a discharge recirculation path disposed in the housing.

18. 17. The method of claim 16, wherein a flow control valve selectively allows fluid communication of the refrigerant from the discharge chamber to the injection chamber.

19. 20. The method of claim 18, wherein the flow control valve is an adjustable expander configured to reduce the pressure of the refrigerant from the discharge pressure to the injection pressure.

20. 17. The method of claim 16, wherein the refrigerant is compressed in the compression space from a suction pressure to the discharge pressure, and the injection pressure is intermediate the suction pressure and the discharge pressure.

Images