eTXV direct discharge jet 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 having a discharge recirculation function.

Background Art

[0002] A thermal management system for use in an electric vehicle can utilize a heat pump system to manage the temperature of various components of the electric vehicle or to heat or cool the air transmitted to the passenger compartment of the vehicle. The heat pump system includes a compressor circulated by a refrigerant, a first heat exchanger serving as a condenser, an expander, and a second heat exchanger serving as an evaporator. The compressor of the system raises the temperature of the refrigerant to supply heat to the downstream condenser, thereby bringing it into a heat exchange relationship with the air transmitted to the passenger compartment. Therefore, the heating capacity of the passenger compartment condenser depends on the temperature of the refrigerant entering the passenger compartment condenser after being compressed in the compressor.

[0003] One shortcoming of such a device occurs especially at low ambient air temperatures where the thermal management system has to increase the heating capacity of the refrigerant in the passenger compartment condenser to meet the heating demand. That is, air at a low ambient temperature can extract sufficient heat from the refrigerant in the passenger compartment condenser, whereby the total heating capacity of the thermal management system can be undesirably reduced. Therefore, in view of such low temperature conditions, it is necessary to provide additional heat to the refrigerant before it is introduced into the passenger compartment condenser.

[0004] As a solution to the problem of increased heating demand in the cabin condenser, the use of a vapor injection scroll compressor for further heating the upstream refrigerant of the cabin condenser is included. The vapor injection scroll compressor utilizes two different inputs of refrigerant having different pressures and / or temperatures respectively to provide advantages compared to conventional scroll compressors. Generally, a scroll compressor includes a fixed scroll type that is in a stopped state and a orbiting scroll that is configured to orbit with respect to the fixed scroll and is enclosed with respect to the fixed scroll. The similar spiral shapes of the fixed scroll and the orbiting scroll respectively, and the orbiting motion of the orbiting scroll continuously forms a substantially symmetric pair of compression chambers between the fixed scroll and the orbiting scroll. Each of the compression chambers is typically symmetric with respect to the central 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 as the orbiting scroll orbits with respect to the fixed scroll, the volume of each pressure chamber gradually decreases, and the pressure of the refrigerant disposed in each pressure chamber gradually increases as the refrigerant approaches the radially central discharge port.

[0005] By injecting the refrigerant returned to each of the compression chambers located at an intermediate position radially disposed between the inlet port disposed on the outside and the discharge port disposed at the center of the fixed scroll, the vapor injection scroll compressor differentiates from the conventional scroll compressor. Therefore, the injected refrigerant enters each of the pressure chambers located in the region of the fixed scroll that repeatedly passes through the pressure of the refrigerant flowing radially inward, which corresponds to an intermediate between the suction pressure formed at the inlet port of the fixed scroll and the discharge pressure formed at the discharge port. The injected refrigerant is derived from the injection chamber of the vapor injection scroll compressor configured to accommodate the refrigerant returned to the inside before re-entering the compression chamber.

[0006] Therefore, the vapor injection scroll compressor can be utilized to inject 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, thereby increasing the heating capacity of the refrigerant exiting the compression chamber. The refrigerant exiting the vapor injection scroll compressor can thus be provided to the cabin condenser at a higher temperature than originally possible when the vapor injection scroll compressor operates without the heated vapor being at an intermediate position within the compressor chamber.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, one disadvantage of using a vapor injection scroll compressor is that it requires integrating additional components into the thermal management system to recycle the refrigerant through the vapor injection scroll compressor at an appropriate temperature and pressure for injecting the refrigerant into the compression chamber according to the selected mode of the thermal management system. In such a system, generally, a bypass path branched from a downstream position of the cabin condenser is included for the return of the refrigerant while bypassing the remaining part of the corresponding primary refrigerant circuit. Such a bypass path also includes an expander for adjusting the temperature and / or pressure of the refrigerant before injection into the compression chamber, and can selectively include an internal heat exchanger located downstream of the expander for adding heat to the recycled refrigerant from the refrigerant flowing along the primary refrigerant circuit after the temperature reduction within the expander. The introduction of such additional components adds cost and complexity to the resulting thermal management system.

[0009] Another problem associated with the system described above relates to the way in which the vapor injection scroll compressor still accommodates refrigerant that has already discharged hot vapor into the ambient air within the cabin condenser due to the downstream placement of the fluid branch in a low path relative to the cabin condenser. Also, when the internal heat exchanger is used downstream of the expander as appropriate, reheating of the refrigerant occurs similarly to the flow of refrigerant that has already been opened and dissipated within the cabin condenser. The introduction of a vapor injection scroll compressor into the thermal management system, therefore, does not account for or address the problems posed, particularly for low ambient temperatures, for the same reasons that are clear from the conventional thermal management systems with insufficient vapor injection as previously described. The pressure of the refrigerant must also necessarily be placed low within the expander arranged along the bypass path in case the refrigerant temperature drops significantly when the refrigerant re-enters the compressor. If the refrigerant is expanded along the bypass path, this results in a limitation of the ability to add heat capacity to the cabin condenser through the use of such a configuration.

[0010] Another way to add heat to the air to be provided to the cabin can include integrating a heating device such as an electrically driven positive temperature coefficient (PTC) heater into the flow path of the air provided to the cabin. However, the introduction of such a heating device adds cost and complexity to the thermal management system and leads to the need to introduce a heating, ventilating, and air conditioning (HVAC) housing to include the heating device in an appropriate position to heat the air properly. Therefore, it is preferable to provide a thermal management system comprising a vapor injection scroll compressor capable of improving the heating capacity of a cabin condenser arranged downstream to cope with increasing heat demand.

Means for Solving the Problem

[0011] A vapor injection scroll compressor with an exhaust recirculation function for increasing the heat capacity of a refrigerant circuit has been surprisingly discovered to be consistent with and in line with the present invention.

[0012] According to the present invention, the compressor includes a compression space where the refrigerant is compressed, and the compression space includes an exhaust port and an injection port. The exhaust chamber is fluidly connected to the compression space by the exhaust port. The injection chamber is fluidly connected to the compression space by the injection port. The exhaust 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 includes discharging the refrigerant from the compression space to the exhaust chamber - the discharged refrigerant has an exhaust pressure, fluidly communicating the refrigerant disposed in the exhaust chamber to the injection chamber, when the refrigerant is in the injection chamber, it has an injection pressure, 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] Other objects and advantages of the present invention, as well as the above content, will become readily apparent to those skilled in the art upon reading the following detailed description of the present invention when considered in conjunction with the accompanying drawings.

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BEST MODE FOR CARRYING OUT THE INVENTION

[0015] The following detailed description and the accompanying drawings are for explaining various embodiments of the present invention. The description and the drawings are for enabling those skilled in the art to make and use the present invention and are not intended to limit the scope of the present invention in any way.

[0016] FIG. 1 illustrates a refrigerant circuit according to an embodiment of the present invention. The refrigerant circuit (10) forms a part of a vehicle's thermal management system. The vehicle can be an electric vehicle or a hybrid vehicle that depends on stored electric power to provide heat to various components of the vehicle as well as the air provided to the vehicle's passenger compartment through the 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 FIG. 1 is essentially simplified and is illustrated within the scope of the present invention without departing therefrom as long as the same relationships exist within the refrigerant circuit (10) for the purpose of explaining the operation by the following method, and can include additional flow paths, valves, and / or components.

[0018] The refrigerant circuit (10) can 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 into the first heat exchanger (13). When the refrigerant circuit is operable in the heat pump mode, the first heat exchanger (13) can be configured as a cabin condenser, and the first heat exchanger (13) can be disposed within an HVAC air handling casing (not shown) of the associated vehicle for a selective heat exchange relationship with the air provided to the cabin. The heated refrigerant releases heat to the air passing through the first heat exchanger (13), heating the air and cooling and condensing the refrigerant. The cooled liquid refrigerant then expands in the expander (14) before heating and returns to the inlet side of the second heat exchanger (15) of the compressor (12) as a gas at a relatively low temperature and pressure, and is evaporated in the second heat exchanger (15) that acts as an evaporator of the refrigerant circuit (10) with respect to the aforementioned flow configuration.

[0019] Although not shown, the refrigerant circuit (10) can include various fluid lines and / or valves for defining a flow configuration by the refrigerant circuit (10) opposite to that described above in connection with heat pump mode operation. For example, the refrigerant circuit (10) is also operable when the refrigerant exits the compressor (12) through the use of a suitable valve and flow path arrangement adjacent to the compressor (12) and generally flows counterclockwise (see FIG. 1), whereby the refrigerant flows through the second heat exchanger (15), the expander (14), and the first heat exchanger (13) in that order. Such an opposite flow configuration results in the first heat exchanger (13) functioning as a cabin evaporator, where heat moves from the air to be provided to the cabin to the refrigerant within the first heat exchanger (13). Therefore, when such a two-way flow configuration is used as necessary, the first heat exchanger (13) can operate as either heating or cooling equipment depending on the order of flow by the refrigerant circuit. Examples of such variable and / or two-way flow configurations are disclosed in Patent Document 1, and the entire content of the patent is incorporated herein by reference.

[0020] In other embodiments, the refrigerant circuit (10) can be absent of such an opposite flow configuration. Instead, when the refrigerant circuit (10) is operable in the heat pump mode described above, the second heat exchanger (15) can be integrated into the HVAC air handling casing to operate as a passenger compartment evaporator. That is, the second heat exchanger (15) can be arranged within such an HVAC air handling casing to cause the refrigerant to selectively pass through in order to cool the air provided to the passenger compartment based on the selection of the air conditioning mode operation of the vehicle passengers.

[0021] The refrigerant circuit (10) can be in heat exchange communication or fluid communication with additional components or systems of the associated vehicle to heat and / or cool the additional components or systems of the associated vehicle. For example, an additional heat exchanger can be in fluid communication with the refrigerant of the refrigerant circuit (10), and such a heat exchanger can be provided as a chiller for cooling the vehicle battery, the heat generating electronic components of the vehicle, etc. Such a chiller can be in fluid and / or heat exchange communication with one or more secondary cooling waters associated with such a secondary system. In other situations, such a heat exchanger can be provided to heat the component in a cold primary state in order to enable the electronic component to operate most efficiently or to potentially evaporate or defrost the water or ice accumulated in the component.

[0022] In any situation, in the following description, the refrigerant circuit (10) can be operated in a heat pump mode with the refrigerant flowing in the direction of the first heat exchanger (13) by the compressor (12), whereby it is assumed that the refrigerant passing through the first heat exchanger (13) can be cooled and the compressor can operate to heat any fluid passing through. The fluid can be the air provided in the passenger compartment of the relevant vehicle. The following structure, in order to reduce the number of components necessary to achieve the advantages of the refrigerant circuit (10) and the compressor (12), and to return the refrigerant to the desired pressure and temperature to utilize the advantages of the disclosed heat management system, even if specific positions and configurations are preferred, it is clearly understood by those skilled in the art that it can be integrated into the refrigerant circuit (10) at any position between the side arranged downstream of the compressor (12) and the side arranged upstream of the first heat exchanger (13) without departing from the scope of the present invention.

[0023] Figure 1 schematically illustrates that the compressor (12) includes a housing (20) that can be separated into a first housing (21) and a second housing (22). In the presented embodiment, the first housing (21) can be conventionally named the "front housing" of the compressor (12), and the second housing (22) can be conventionally named the "rear housing" of the compressor. The front housing (21) can be arranged towards the first end through which the refrigerant first enters the compressor (12), and this part corresponds to the inlet end of the compressor (12). The rear housing (22) can be arranged towards the second end of the housing (20) corresponding to the part where the refrigerant exits the compressor (12) after being compressed in the compressor (12), and this part corresponds to the outlet end of the compressor (12). The front housing (21) and the rear housing (22) can each be provided in a substantially hollow skin-like shape that defines an open space, and the housings 21 and 22 can be joined to each other along a circumferentially extending seam, and the open space is formed by the cooperation of the housings 21 and 22 that accommodate various components of the compressor.

[0024] The compressor (12) generally includes an intake chamber (31), a compression space (32), a discharge chamber (33), and a steam injection chamber (34). The intake chamber (31) can be disposed within the front housing (21) and forms a space within the housing (21) for the first inflow of a relatively low-pressure and low-temperature gaseous refrigerant to be provided to the compression space (32). The compression space (32) means the space inside the housing (20), and a swivel scroll (not shown) swivels with respect to a fixed scroll for repeatedly generating a pair of compression chambers (not shown) between the fixed scroll and the swivel scroll inside the compression space (32). Such a compression chamber is repeatedly formed radially inward from the radially outer portion of the compression chamber (32) toward the radially central portion of the compression space (32) while the swivel scroll swivels with respect to the fixed scroll, and progresses. Such continuous radial progression of the compression chamber causes the pressure of the refrigerant stored in each of the compression chambers to increase toward the radially central portion of the compression space (32). Also, such progression results in a variable and substantially periodic pressure being received as each position seen within the compression space (32) passes through the repeatedly formed compression chambers, while the pressure gradually increases due to the volume reduction of each compression chamber.

[0025] The compression space (32) can include at least one inlet (35) for allowing the refrigerant to flow into the compression space (32) at the suction pressure and at least one discharge port (36) for discharging the refrigerant from the compression space (32) at the discharge pressure due to compression in each compression chamber that progresses radially inward. Each of the inlets (35) can be provided, for example, as an opening formed in the outer peripheral wall of the fixed scroll or orbiting scroll to provide fluid communication between the suction chamber (31) and the compression space (32), but is not limited thereto. The discharge port (36) can be provided, for example, as an opening in the 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), but is not limited thereto. A general configuration and operating method of a scroll compressor having such a compression space formed by an orbiting scroll that moves relative to a fixed scroll are disclosed in U.S. Patent No. 11,002,272 (Klotten et al.) which is co-owned, and the entire content thereof is incorporated herein by reference.

[0026] A discharge check valve (37) can be arranged at the discharge port (36) between the compression space (32) and the discharge chamber (33). The discharge check valve (37) is configured to be opened only when the pressure of the refrigerant at the position of the discharge port (36) in the compression space (32) exceeds the bias for inflow by the discharge check valve (37) as well as the pressure of the refrigerant in the discharge chamber (33). The discharge check valve (37) can be a reed valve that bends each time the compression and the force difference described above are reached while the compression chamber progresses repeatedly toward the discharge port (36), and such bending tends to open a passage leading to the discharge port (36). However, alternative one-way check valve configurations can be utilized without departing from the scope of the present invention. The discharge check valve (37) prevents the refrigerant from flowing back undesirably into the compression space (32) while the orbiting scroll moves in a circular motion relative to the fixed scroll.

[0027] The compression space (32) can further include a pair of injection ports (38) for selectively providing fluid communication between the compression space (32) and the steam injection chamber (34). Each injection port (38) can be provided as an opening, for example, in the axial end wall of the fixed scroll intermediate between the inlet port (35) and the discharge port (36) with respect to the radial direction of the fixed scroll, but is not limited thereto. FIG. 1 schematically illustrates a manner in which the injection port (38) communicates with the compression space (32) at a position intermediate in the radial direction between the inlet port (35) and the discharge port (36).

[0028] The injection check valve (39) can be disposed at each of the injection ports (38) between the compression space (32) and the steam injection chamber (34). Each of the injection check valves (39) is configured to open only when the refrigerant pressure in the steam injection chamber (34) exceeds the bias that flows in through the associated injection check valve (39) as well as the refrigerant pressure in the compression space (32) at the position of the injection port (38). Each of the injection check valves (39) can be a lead valve that bends with respect to the injection port (38) each time the pressure and force difference described above is reached while the compression chamber progresses repeatedly toward the injection port (36), and such bending tends to open a passage through the injection port (38) to selectively provide fluid communication between one instantaneously aligned within the compression chamber formed in the steam injection chamber (34) and the compression space (32).

[0029] Each of the injection check valves (39) prevents the refrigerant from flowing undesirably toward the vapor injection chamber (34) in the compression space (32) while the orbiting scroll moves in a circular motion relative to the fixed scroll. The injection check valve (39) also allows the refrigerant admitted to enter from the vapor injection chamber (34) into the compression space (32) to have a pressure greater than that of the refrigerant already in the compression space (32) in one of the compression chambers where the refrigerant progresses radially inward, so that the pressure (and temperature) in the compression chamber can increase through the vapor injection process described above. The refrigerant entering the pressure chamber in the vapor injection chamber (34) thus comes to be at an intermediate injection pressure intermediate between the instantaneous suction pressure and the instantaneous discharge pressure of the compressor. The injection check valve (39) can represent a vapor injection double reed valve assembly operating in a vapor injection scroll compressor disclosed in Patent Document 2, the entire content of which is incorporated herein by reference. However, an alternative one-way check valve structure can be utilized within the scope not departing from the present invention if necessary.

[0030] An oil separator (40) for removing oil with the discharged refrigerant can be disposed inside the discharge chamber (33). The oil separator can be of any structure for removing such oil and can include a centrifugal force or surface area increasing function for capturing the oil exposed to the oil separator (40). Any suitable oil separator (40) can be utilized within the scope not departing from the present invention.

[0031] As schematically illustrated in FIG. 1, when not the entire discharge chamber (33), steam injection chamber (34), and compression space (32), at least a portion can be formed or disposed within the rear housing (22) of the housing (20). The various different spaces can be at least partially defined by a combination of the inner surface of the rear housing (22), the surface of the fixed scroll, the surface of the orbiting scroll, and the surfaces forming intermediate valve assemblies such as the check valves (37, 39) described. The front housing (21) can include not only the suction chamber (31) but also the components necessary to induce the orbiting of the orbiting scroll relative to the fixed scroll.

[0032] The compressor (12) is distinguished from prior art steam injection scroll compressors in that it introduces a discharge recirculation path (50) formed within the housing (20) to fluidly couple the discharge chamber (33) to the steam injection chamber (34). The refrigerant disposed within the discharge chamber (33) is selectively communicated through the discharge recirculation path (50) to the steam injection chamber (34) through the operation of a flow control valve (52) disposed therealong. The flow control valve (52) can be configured to provide a variable orifice through which the refrigerant can flow through when flowing from the discharge chamber (33) to the steam injection chamber (34), and the flow area by the variable orifice not only changes the temperature and pressure changes of the refrigerant passing through the flow control valve (52) according to the degree of contraction and expansion of the flow area by the flow control valve (52) for the segments disposed upstream and downstream of the discharge recirculation path (50), but also determines the flow rate of the recirculated refrigerant flowing from the discharge chamber (33) to the steam injection chamber (34).

[0033] Accordingly, the described exhaust recirculation path (50) and the flow control valve (52) are allowed to be operable in an exhaust recirculation operating mode by the compressor (12), and refrigerant having an exhaust pressure in the exhaust chamber (33) can be in fluid communication with the steam injection chamber (34) for injection into the compression space (32) at an intermediate injection pressure through one of the injection check valves (39). The intermediate injection pressure can be different from the exhaust pressure due to the pressure loss experienced by the refrigerant when passing through the exhaust recirculation path (50) and the flow control valve (52). The intermediate injection pressure, therefore, maximizes when the variable orifice is adjusted through the flow control valve (52) to the maximized flow area corresponding to the minimized pressure loss of the flow control valve (52). The refrigerant located at the intermediate injection pressure has a pressure greater than the pressure instantaneously disposed within the compression chamber that can substantially correspond to the instantaneous suction pressure of the refrigerant during the initial formation of the compression chamber in certain situations and is injected into the compression space (32) and the corresponding compression chamber through one of the injection ports (38).

[0034] The injection of the refrigerant with an increased pressure into the compression chamber causes an increase in the total pressure of the refrigerant within the compression chamber, which directly corresponds to an increase in the temperature of the refrigerant held within the compression chamber. Such an increased temperature of the refrigerant within the compression space (32) causes the refrigerant to be discharged to the exhaust chamber (33) having a higher temperature than if no recirculation of the refrigerant occurred through the injection process described above. Such an increased temperature discharged refrigerant can then be partially recirculated once again through the exhaust recirculation path (50). Accordingly, the repetition of this process occurring at a given operating state of the compressor (12) results in a gradual increase in the discharged refrigerant temperature for each cycle until a new recirculation discharge temperature is reached that is higher than the discharged refrigerant temperature during operation of the compressor (12) without the recirculation function in the same setting. The exhaust recirculation process, therefore, causes the discharged refrigerant to reach the first heat exchanger (13) having a higher temperature than if the recirculation process were absent after exiting the compressor (12), which results in an increase in the heating capacity of the first heat exchanger (13) during operation of the exhaust recirculation mode of the compressor (12).

[0035] Through experiments on various compressors having the general configuration shown in FIG. 1, it has been discovered that the use of the disclosed discharge recirculation function causes the ability to maintain a coefficient of performance (COP) greater than 1.0 while simultaneously raising the refrigerant discharge temperature significantly. For example, it has been found that the compressor refrigerant discharge temperature can be raised to 30 to 70 °C depending on the compressor configuration while maintaining a COP greater than 1.0. Also, it has been discovered that such a temperature increase occurs with a less than 10% decrease in the mass flow rate of the refrigerant exiting the compressor compared to the mass flow rate associated with the operation of a compressor without the discharge recirculation function. While having a COP of 1.0 or more, the ability to raise the temperature of the discharged refrigerant in response to passenger heating demands means that it can be utilized instead of adding a heating device such as an electric-driven PTC heater 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 discharge recirculation function for the compressor (12) simplifies the thermal management system having the refrigerant circuit (10) and the compressor (12) by allowing it to be provided with a minimized number of components by the HVAC casing.

[0036] To prevent flow from the discharge chamber (33) to the steam injection chamber (34) through the discharge recirculation path (50), the flow control valve (52) can be configured to be adjusted to an all-closed position. The flow control valve (52) can be further configured to be adjusted from an all-closed position to an all-open position to maximize the flow area through the discharge recirculation path (50). The flow control valve (52) can also be configured to be adjusted to a plurality of intermediate positions corresponding to other flow areas between the all-closed and all-open positions through the discharge recirculation path (50), and each other flow area can correspond to other changes in the pressure and temperature of the refrigerant being recirculated, as well as to each other flow rate of the refrigerant by the flow control valve (52). However, in other alternative embodiments, the flow control valve (52) can not include an adjustable flow function, and instead can be configured to be adjustable only between an open position to allow the discharge recirculation process, if desired, and a closed position to prevent the process.

[0037] The adjustment of the flow control valve (52) can be determined by various elements associated with the operation of the compressor (12) and / or the rest of the refrigerant circuit (10). In certain situations, the flow control valve (52) can be controlled by a desired configuration corresponding to a defined flow of the refrigerant through the recirculation path (5), and such control can be based on the selected operating mode or conditions measured by the compressor (12) or the rest of the refrigerant circuit (10). For example, a temperature sensor can be arranged along the refrigerant circuit (10) at a desired location to monitor the refrigerant at relevant locations such as directly upstream of the first heat exchanger (13), directly downstream of the first heat exchanger (13), or possible other locations within the discharge chamber (33) for monitoring the refrigerant temperature in relation to the heating capacity of the refrigerant, or a combined position of such positions.

[0038] The flow control valve (52) can be opened only when the recirculation function described above that is necessary to meet the heating requirements of the refrigerant circuit (10) is required, such as when it senses that the temperature of the refrigerant at one or more of the aforementioned positions is lower than the level required for air heating provided to the passenger compartment within an acceptable range that can occur when the first heat exchanger (13) is exposed to a particularly low ambient air temperature. The flow control valve (52) can alternatively be controlled based on the measured temperature of the air provided to the passenger compartment, and the recirculation function can be activated when the temperature of the air provided to the passenger compartment is not heated in accordance with the setting selected by the passenger. Also, the flow control valve (52) can be controlled based on a combination of such elements, if desired.

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

[0040] The fully open position of the flow control valve (52) can thus handle situations such as when there is a particularly high heating demand in the refrigerant circuit (10), such as when the refrigerant exchanges heat with the ambient temperature at a particularly low temperature within the passenger compartment condenser (13). The flow control valve (52) can be adjusted to one of the intermediate positions corresponding to an intermediate position between the fully closed position and the fully open position to meet the desired or specified heating requirements of the refrigerant circuit (10).

[0041] The flow control valve (52) can be configured to close or move towards an initially closed position when the temperature of the refrigerant exceeds a preselected value associated with potential damage or inefficient operation of the compressor (12) and / or other components disposed along the refrigerant circuit (10). It can be configured to interrupt the recirculation function of the compressor (12) when the temperature of the refrigerant at a selected location along the refrigerant circuit (10), including what is contained within the compressor (12), exceeds one of a plurality of preselected temperature values that can be tolerated in relation to the various components disposed along the refrigerant circuit (10).

[0042] The flow control valve (52) can also be adjusted to an all-open position where recirculation to the discharge refrigerant vapor injection chamber (34) is not required, such as when the heating demand requested of the refrigerant circuit (10) is low while the aforementioned heat pump mode is activated, or when the refrigerant circuit (10) operates to cool the air provided to the vehicle passenger compartment or other heat generating components, such that the temperature of the refrigerant downstream of the compressor (12) does not need to be adjusted particularly high in an alternative operating mode.

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

[0044] The rear housing (22) includes a discharge chamber (33) that is divided into a first part (33a) and a second part (33b), as shown in the figure. The first part (33a) is arranged immediately downstream of the discharge port (not shown in FIGS. 3 to 8), and the second part (33b) is arranged downstream of the first part (33a) and extends far from the first part (33a). A flow opening (33c) fluidly connects the first part (33a) to the second part (33b). The second part (33b) is shown as a cylindrical conduit that extends at least partially radially outward with respect to the position of the corresponding discharge port (36) of the compressor (12). The second part (33b) can be formed in a bore that is externally inserted into the rear housing (22) if necessary. The end of the second part (33b) facing the first part (33a) is configured to be coupled to an external fluid line, component, etc. to communicate with the refrigerant downstream of the compressor (12). For example, the second part (33b) can be fluidly coupled to a fluid line that leads to the first heat exchanger (13).

[0045] Although not shown in FIGS. 3 to 8, the aforementioned oil separator (40) can flow into the discharge chamber (33) at the flow opening (33c) or immediately downstream of the flow opening (33c) or at an upstream position of the discharge recirculation path (50) to ensure that oil has been removed from the discharged refrigerant before flowing into the discharge recirculation path (50). The oil separator (40) can be an oil ring built into the cylindrical structure of the second part (33b) of the discharge chamber (33). However, the oil separator (40) can be arranged at any position within the discharge chamber (33), including downstream of the discharge recirculation path (50), without departing from the scope of the present invention, and can include any structure and configuration suitable for separating oil from the refrigerant.

[0046] The rear housing (22) also includes a steam injection chamber (34) divided into a first part (34a) and a second part (34b) as shown in the figure. The first part (34a) can be arranged upstream immediately adjacent to the injection check valve (39), and the second part (34b) is arranged upstream of the first part (34a) and extends far from the first part (34a). The flow direction described above means the flow of the refrigerant from the discharge chamber (33) to the steam injection chamber (34) through the discharge recirculation path (50). The flow opening (34c) fluidly connects the first part (34a) to the second part (34b). The second part (34b) is shown as a cylindrical conduit extending at least partially radially outward with respect to the position of the discharge port (36) of the compressor (12). Optionally, the second part (34b) can be formed in a bore externally inserted into the rear housing (22). The end of the second part (34b) facing the first part (33a) has a structure coupled to an external fluid line, component, etc. to communicate the refrigerant to the compressor (12) for inflow into the steam injection chamber (34). However, as shown in FIG. 3, the end of such a second part (34b) can be capped to fluidly isolate the second part (34b) from the external fluid communication at the end, which corresponds to the flow configuration of the steam injection chamber with respect to the discharge recirculation path (50) shown in FIG. 1. As will be described below, it is also possible to alternatively not use such capping to allow the inflow of another refrigerant flow into the compressor (12) for use in the steam injection process through the connection of the second part (34b) to an external component.

[0047] The second part (33b) of the discharge chamber (33) and the second part (34b) of the steam injection chamber (34) can be formed inside the rear housing (22) in such a way that they are angularly displaced from each other by less than 90 degrees for a direct and shortened extension of the discharge recirculation path (50) between both sides. The discharge recirculation path (50) can be formed within a bridge portion (80) of the rear housing (22) that extends left and right between 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 outer surface of the rear housing (22) into the rear housing (22), extends into the connecting bridge portion (80), and intersects and passes through the second part (33b) of the discharge chamber (33) before being interrupted inside. The guide opening (82) can be formed inside the rear housing (22) as a cylindrical bore 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 steam injection chamber (34) side. The first flow segment (61) forms an inlet port to the discharge recirculation path (50) and extends laterally from the second part (33b) of the discharge chamber (33) before intersecting the first flow space (62). The first flow space (62) includes an L-shape to extend around the guide opening (82) by the downstream part of the first flow space (62) and be axially aligned with the guide opening (82). The irregular shape of the first flow space (62) causes the refrigerant velocity to decrease before the refrigerant passes through the orifice (63), thereby reducing the pressure loss occurring in the passage through the orifice (63). The orifice (63) is provided in the end segment of the guide opening (82) extending axially between the first flow space (62) and the second flow space (64). The second flow space (64) extends laterally in a direction away from the guide opening (82) before intersecting the second flow segment (65). The second flow segment (65) extends longitudinally and intersects toward the second part (34b) of the steam injection chamber (34) to form the discharge port of the discharge recirculation path (50). The second flow segment (65) can be formed in a cylindrical bore form introduced from the outside in a manner similar to the guide opening (82), and a part of the rear housing (22) having a bore flowing into the rear housing (22) can then be capped.

[0049] The illustrated exhaust recirculation path (50) can be defined between the recessed outer surfaces of the bridge portion (80) of the rear housing (22), and the opposing surfaces of the cover plate (90) are coupled to the bridge portion (80) on the exhaust recirculation path (50). The cover plate (90) can be coupled to the rear housing (22) through, for example, threaded fasteners, but is not limited thereto. As illustrated in FIGS. 4 and 5, a sealing element can be disposed between the outer surface of the bridge portion (80) and the opposing surface of the cover plate (90), and the sealing member (92) can extend in a form surrounding the periphery of the flow spaces (61, 62, 63, 64, 65) formed by the recessed outer surface of the bridge portion (80). The sealing member (92) provides a fluid seal for the exhaust recirculation path (50) between the bridge portion (80) and the cover plate (90).

[0050] In forming the exhaust recirculation path (50) and related functions, the use of various externally introduced bores and the recesses introduced into the rear housing (22) allows for ease of manufacture of the compressor. Such functions also allow for easy repair or replacement in the event of damage or malfunction of the function.

[0051] The flow control valve (52) includes a flow control member (55) and a temperature-dependent member (56). In the presented embodiment, the flow control member (55) is a cylindrical rod slidably received axially within the guide opening (82). The flow control member (55) extends inside the bridge portion (80) of the rear housing (22) through the second portion (33b) of the discharge chamber (33). The flow control member (55) can include a large-diameter (cylindrical) portion (57) dimensioned to slidably engage the guide opening (82) and conform to the guide opening (82), a small-diameter portion (58) formed at the end of the flow control member (55) extending inside the flow spaces (62, 63), and a frustoconical portion (59) having a taper to connect the small-diameter portion (58) to the large-diameter portion (57).

[0052] The temperature-dependent member (56) is disposed along the outer surface of the rear housing (22) and defines a communication space (84). The communication space (84) is in fluid communication with a second portion (33b) of the discharge chamber (33) through a part of the guide opening (82) that surrounds the flow control member (55). The temperature-dependent member (56) includes a thermally activated spring (not shown) that engages a diaphragm (not shown) connected to the closest end of the flow control member (55). The thermally activated spring is configured to apply an increasing axial force to the diaphragm and the connected flow control member (55) when exposed to increasing temperature. The thermally activated spring can react to the temperature of the discharge refrigerant in the second portion (33b) of the discharge chamber (33) by exposing the temperature-dependent member (56) to the refrigerant in the communication space (84). Thereby, the increasing temperature of the discharge refrigerant corresponds to the flow control member (55) that enters the bridge portion (80) of the rear housing (22) while the large diameter portion (57) approaches the orifice (63).

[0053] The flow area by 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 from FIGS. 3 and 4, the continuous axial advancement of the flow control member (55) first includes the inflow of the small diameter portion (58) of the flow control member (55) into the orifice (63) and the reduction of the flow area of the small diameter portion (58) before the frustoconical portion (59) subsequently enters the orifice (63) and further gradually reduces the flow area. The orifice (63), and thus the discharge recirculation path (50), is closed when the large diameter portion (57) is received within the orifice (63) or alternatively when the end of the frustoconical portion (59) is seated against the surface that defines the orifice (63).

[0054] Therefore, the aforementioned flow control valve (52) having temperature dependence can allow the maximum flow by the exhaust recirculation path (50) for temperatures below the first critical value, and can start to variably decrease the flow area for the temperature range between the first critical value and the second critical value greater than the first critical value, thereby decreasing the flow rate by the exhaust recirculation path (50). The flow control valve (52) can completely close the exhaust recirculation path (50) when reaching the second critical temperature, which can correspond to the maximum allowable safety temperature related to the operation of the compressor (12) and / or any component related to the refrigerant circuit (10).

[0055] Also, the illustrated flow control valve (52) can be configured to include a shut-off function related to the control system of the refrigerant circuit (10). Such a shut-off function can be electronically controlled by the control method of a control system that can include any state sensing of the aforementioned compressor (12) and / or refrigerant circuit (10). For example, when the flow control member (55) generates a control signal indicating that the recirculation function is not required for the associated controller, it can be mechanically coupled to a solenoid-based actuator configured to advance the flow control member (55) toward the closed position. Alternatively, a secondary valve member (not shown) can be utilized to open or close the exhaust recirculation path (50) at a position spaced apart from the illustrated orifice (63) and the flow control member (55) so as to provide an adjustable member configured to selectively extend across the second flow segment (65) in response to the generated control signal. Once again, the position of such a secondary valve member can be controlled using a solenoid or a similar electrically adjustable and electronically controllable function.

[0056] As shown in FIGS. 9 and 10, another embodiment of the exhaust recirculation path (50) and associated flow control valve (52) according to another embodiment of the present invention is disclosed, assuming that the remainder of the compressor (12) is the same and operates in the same manner as disclosed in FIGS. 1 or 2 to 8. The exhaust recirculation path (50) includes a first flow space (62) that acts as an inlet into the path (50) from a second portion (33b) of the exhaust chamber (33) and a second flow space (65) that acts as an outlet from the path (50) toward a second portion (34b) of the steam injection chamber (34). The flow control valve (52) is provided as a ball valve that forms a variable orifice (63) intermediate the adjacent flow spaces (62, 64). The ball valve includes a rotatable ball member coupled to the rotor of the actuator. The actuator can be an electrically adjustable and electronically controllable rotary actuator configured to rotate the ball member relative to the flow spaces (62, 64). The ball member includes a flow passage that includes a variable overlap with the respective flow spaces (62, 64) depending on the rotational position of the ball member corresponding to the formation of the variable orifice (63). The actuator has no overlap between the flow spaces (62, 64) and the flow passage passing through the ball member, and thus has an all-closed position where there is no flow region, a fully open position where there is a maximum overlap and a flow region between the flow passage and the flow spaces (62, 64) due to the alignment of the flow space and the flow passage, and a plurality of intermediate positions including an intermediate flow region based on the variable overlap between the flow regions existing between the flow passage and the flow spaces (62, 64), and is configured to adjust the ball member to these intermediate positions.

[0057] The flow control valves (52) of FIGS. 9 and 10 can be actuated by any of the control methods described above. For example, the flow control valve (52) can be opened only for the flow through the discharge recirculation path (50) when a recirculation function is required to obtain the desired heat capacity of the first heat exchanger (13), and can be additionally closed during the recirculation process when the temperature of the discharged refrigerant exceeds a critical value associated with potential damage to the compressor (12) and / or other components of the refrigerant circuit (10). The electronically controlled only version of the flow control valve (52) includes a passive shut-off function, and thus the determination regarding the adjustment of the flow control valve (52) can be based on the sensed conditions described above for the refrigerant circuit (10) and / or the air delivered to the vehicle passenger compartment.

[0058] It will be appreciated that other configurations of the discharge recirculation path (50) can be provided within the rear housing (22) for use with other adjustable flow control valves (52) without departing from the scope of the invention as long as the same basic relationships described herein are maintained. Thus, the disclosed mechanisms utilized to form a variable orifice through the discharge recirculation path are not limited to the general configuration of the compressor (12) illustrated in FIG. 1. The flow control valve (52) can represent an alternative expansion valve configuration while remaining within the scope of the 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), which are hereinafter referred to as forming a primary loop of the refrigerant circuit (110). However, the refrigerant circuit (110) further includes a bypass feature similar to that typically found in a refrigerant circuit operating with a bypass intercooler and a conventional vapor injection scroll compressor (without the currently disclosed discharge recirculation function). The bypass feature is presented as a bypass path (150) that extends from a position in the primary loop of the refrigerant circuit (10) disposed downstream of the first heat exchanger (13) within the compressor (12) to a vapor injection chamber (34) disposed upstream of the expander (14).

[0060] The bypass path (150) includes an expander (152) and an intercooler (154) disposed downstream. The intercooler (154) is also disposed along the primary loop of the refrigerant circuit (110) at an intermediate position of the branch 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) can be adjusted to include a variable flow region by 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 gaseous state for introduction into the compressor (12). If necessary, the expander (152) can alternatively represent a fixed metering orifice used with a shutoff valve for preventing undesired flow by 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 it to enter the intercooler (154) along the bypass path with a temperature lower than that of the refrigerant entering the intercooler (154) along the primary loop of the refrigerant circuit (110). Thus, while the primary loop is cooled within the intercooler (154), the bypassed gaseous refrigerant is heated within the intercooler (154).

[0062] The bypassed refrigerant reaching the steam 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 within the compression chamber. Thus, the refrigerant at the intermediate injection pressure can still raise the discharge temperature of the refrigerant, although to a very low degree, 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 within the compressor (12), which in turn helps to increase the refrigerant temperature in the first heat exchanger (13) arranged downstream. The injection of the bypassed refrigerant can thus 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 the refrigerant by the primary loop of the refrigerant circuit (110) occurring within the intercooler (154) also tends to result in an increase in the cooling capacity of the second heat exchanger (15) compared to the operation of the refrigerant circuit (110) without the bypass of the refrigerant passing through the bypass path (150). If the second heat exchanger (15) is arranged as the passenger compartment evaporator of the refrigerant circuit (110), such an increase in cooling capacity can be used to help cool the heat generating components in heat exchange relationship with the refrigerant circuit (110) or to cool the air provided to the passenger compartment.

[0064] As shown in FIG. 11, the compressor (12) still includes an exhaust recirculation path (50) to fluidly couple the discharge chamber (33) to the steam injection chamber (34). The steam injection chamber (34) will thus be selectively in fluid communication with each of the bypass path (15) by opening of the expander (152) (or the shut-off valve if a fixed orifice is utilized) and the discharge chamber (33) by opening of the flow control valve (52).

[0065] The configuration of FIG. 11 can be utilized to handle various different operating modes of the compressor (12) and the refrigerant circuit (110). For example, 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) lower than what is possible through the use of the exhaust recirculation function is required, the bypass injection function associated with the bypass path (150) can be utilized. When the bypass injection function cannot impart the desired heating capacity to the first heat exchanger (13), the exhaust recirculation function associated with the exhaust recirculation path (50) can be utilized. The disclosed refrigerant circuit (110) is thus allowed to improve both the heating and cooling effects of the refrigerant circuit (100) through the use of the compressor (12) having a dual steam injection function.

[0066] The flow control valve (52) and the expander (152) can be adjusted and controlled to alternately switch the source of the refrigerant entering the steam injection chamber (34) according to a selected mode of operation of the compressor (12) and / or the refrigerant circuit (110). Also, although such an increase in cooling capacity can be limited by the overall increase in temperature imparted by the recirculation process, it is preferable to further increase the heating capacity of the first heat exchanger while maintaining the increase in cooling capacity of the second heat exchanger (15). In this case, there may exist a situation where the refrigerant from both paths 10 and 150 is in fluid communication with the steam injection chamber (34) so as to utilize the refrigerant in the discharge recirculation path (50) to complement the flow through the bypass path (150). For example, while maintaining the heat exchange relationship in the intercooler (154), the flow control valve (52) can be adjusted such that the refrigerant from the discharge recirculation path (50) has a higher pressure than the refrigerant from the bypass path (150). Here, despite the increase in temperature imparted to the refrigerant exiting the compressor (12), the refrigerant flowing towards the second heat exchanger (15) is cooled sufficiently to improve the cooling capacity.

[0067] Referring to the embodiment of the compressor (12) illustrated in FIG. 3, the second part (34b) of the steam injection chamber (34) can be provided without the illustrated cap to allow the exposed end of the second part (34b) to be fluidly coupled to an external fluid line or component such as the bypass path (15) illustrated in FIG. 11. Similarly, the embodiments of the compressor (12) illustrated in FIGS. 9 and 10 can include the ability to fluidly connect through the end of the illustrated second part (34b) of the steam injection chamber (34). However, it is clear that the disclosed flow configurations can be implemented through other structural relationships without departing from the scope of the present invention.

[0068] As shown in FIG. 12, a refrigerant circuit (210) according to another embodiment of the present invention is disclosed. The refrigerant circuit (210) is substantially identical to the refrigerant circuit (10), except that the discharge recirculation path (50) and the corresponding flow control valve (52) are removed from the position 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) at a position between the compressor (12) and the first heat exchanger (13) to the vapor injection chamber (34) of the compressor (12). Here, the external fluid line (60) includes a flow control valve (52) arranged along the external fluid line (60). In one example, the external fluid line (60) can be coupled to the 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) provided with the flow control valve (52) as the discharge recirculation path (50) still allows an increase in the discharge temperature of the refrigerant, but the advantages described above in terms of the ability to form a short and direct path within the housing (20) without an intervening component-fluid connection cannot be recognized. The external fluid line (60), if necessary, requires an additional fluid connection to the rear housing (22) of the compressor (12) for communication with the discharge chamber (33), although such a configuration is not preferred as described below. Alternatively, it can be an additional fluid line that connects far from the compressor in addition to the fluid line that connects towards the first heat exchanger (13).

[0069] By means of a manner in which the introduction of the discharge recirculation path (50) and the flow control valve (52) generally requires only a modification of the rear housing (22) of the existing compressor (12) having the configuration of FIG. 1 for performing the injection process, the configuration of the compressor (12) disclosed in the present invention can be advantageously integrated as an existing system. The configuration of the rear housing (22) disclosed in FIGS. 3 to 10 can also be changed for use in any of the other circuits illustrated in FIGS. 1, 11, and 12 by virtue of the inclusion of a vapor injection chamber (34) having the ability to be externally fluid-coupled or alternatively capped to different components depending on the situation.

[0070] From the foregoing 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 various modifications can be applied to enable the present invention to be applicable to various uses and conditions.

Description of Reference Numerals

[0071] 10 Refrigerant circuit 12 Compressor 13 First heat exchanger 14 Expander 15 Second heat exchanger 20 Housing 21 First housing 22 Second housing 31 Suction chamber 32 Compression space 33 Discharge chamber 33a First part 33b Second part 33c Flow opening 34 Steam injection chamber 34a First part 34b Second part 34c Flow opening 35 Inlet / discharge port 36 Discharge port 37 Discharge check valve 38 Injection port 39 Injection check valve 40 Oil separator 50 Discharge recirculation path 52 Flow control valve 55 Flow control member 56 Temperature-dependent member 57 Large-diameter (cylindrical) part 58 Small-diameter part 59 Frustum-shaped part 60 External fluid line 61 First fluid segment / flow space 62 First flow space / flow space 63 Orifice / flow space 64 Second flow space Flow space 65 Second flow segment Flow space 80 Bridge part 82 Guide opening 84 Communication space 90 Cover plate 92 Sealing member 100 Refrigerant circuit Refrigerant circuit 110 Refrigerant circuit 150 Bypass path 152 Expander 154 Intercooler 210 Refrigerant circuit

Claims

1. Comprising a discharge port and an injection port, a compression space where the refrigerant is compressed, A discharge chamber communicated with the compression space by the discharge port, An injection chamber communicated with the compression space by the injection port, And including a discharge recirculation path that selectively provides fluid communication between the discharge chamber and the injection chamber, The compressor is characterized in that the compression space, the discharge chamber, the injection chamber, and the discharge recirculation path are all arranged within the housing of the compressor.

2. The compressor according to claim 1, further comprising a flow control valve arranged along the discharge recirculation path to provide the fluid communication between the discharge chamber and the injection chamber.

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

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

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

6. The compressor according to claim 5, wherein the flow control valve further includes an electronic control cutoff function to prevent fluid communication between the discharge chamber and the injection chamber.

7. The compressor according to claim 3, wherein the flow control valve is electronically controlled.

8. The compressor according to 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. The refrigerant is compressed from the suction pressure to the discharge pressure in the compression space, and the refrigerant at the discharge pressure enters the discharge chamber through the discharge port. When the refrigerant passes through the discharge recirculation path, the pressure decreases to an injection pressure that is intermediate between the suction pressure and the discharge pressure at the discharge pressure. The refrigerant at the injection pressure is selectively communicated with the compression space through the injection port. The compressor according to claim 1 is characterized in that.

10. The injection of the refrigerant at the injection pressure into the compression space causes a temperature rise of the refrigerant at the discharge port. The compressor according to claim 9 is characterized in that.

11. The housing is divided into a front housing and a rear housing, and the compression space, the discharge chamber, the injection chamber, and the discharge recirculation path are all arranged in the rear housing. The compressor according to claim 1, characterized in that.

12. The discharge recirculation path is a fluid line connecting the discharge chamber to the injection chamber, and at least a part of the fluid line extends outside the housing. The compressor according to claim 1, characterized in that.

13. As a refrigerant circuit including the compressor according to claim 1, the refrigerant circuit further includes a condenser, a first expander, and an evaporator along a primary loop of the first expander, and the refrigerant circuit extends to the injection chamber of the compressor along the primary loop at a position between the condenser and the expander. A refrigerant circuit characterized by further including a bypass path.

14. The bypass path includes a second expander and an intercooler, and the intercooler is 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. The refrigerant circuit according to claim 13, characterized in that.

15. The step of discharging the refrigerant from the compression space to the discharge chamber - the discharged refrigerant has a discharge pressure, The step of fluidly communicating the refrigerant disposed in the discharge chamber with the injection chamber, and the refrigerant has an injection pressure when it is in the injection chamber, Including the step of injecting the refrigerant at the injection pressure into the compression space to increase the pressure and temperature of the refrigerant in the compression space, The compression space, the discharge chamber, and the injection chamber are all arranged in the housing of the compressor, and the refrigerant is fluidly communicated from the discharge chamber to the injection chamber through a discharge recirculation path arranged in the housing. A method of operating a compressor, characterized in that.

16. The flow control valve selectively permits the fluid communication of the refrigerant from the discharge chamber to the injection chamber. The method of operating a compressor according to claim 15, characterized in that.

17. The flow control valve is an adjustable expander configured to reduce the pressure of the refrigerant from the discharge pressure to the injection pressure. The method of operating a compressor according to claim 16, characterized in that.

18. The refrigerant is compressed from the suction pressure to the discharge pressure in the compression space, and the injection pressure is intermediate between the suction pressure and the discharge pressure, the method of operating a compressor according to claim 15.

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