System and method for map interpolation-based control of injectors in injector refrigeration circuit

Abstract

A system for map interpolation based control of injectors in an injector refrigeration circuit includes a controller coupled to each of the injectors and adapted to generate a map based on predefined conditions. The controller identifies a first atlas associated with a first temperature of the heat rejection heat exchanger and a second atlas associated with a second temperature of the heat rejection heat exchanger. The controller predicts a percentage of opening of the first injector from at least one of the percentage of opening indicated in the first map and the percentage of opening indicated in the second map. Finally, the controller adjusts an opening percentage of the first injector based on the predicted opening percentage.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 591,576, filed on October 19, 2023, which is incorporated herein by reference in its entirety. Technical Field

[0002] The present disclosure relates generally to ejector refrigeration circuits. More particularly, the present disclosure relates to a system for controlling a plurality of ejectors in an ejector refrigeration circuit. Background Art

[0003] Ejectors are sometimes used to increase the overall efficiency of commercial refrigeration systems. Ejectors increase the efficiency of refrigeration systems by using high pressure to help compress low pressure gas (rather than relying solely on the compressor).

[0004] Typically, the ejector may be located between the outlet of the heat rejection heat exchanger and the inlet of the receiving tank. The ejector includes a primary high-pressure inlet, a secondary low-pressure inlet, and an outlet. When the ejector is used as part of a refrigeration system, the cooling refrigerant from the heat rejection heat exchanger enters each of the ejectors at the high-pressure inlet and expands to a lower pressure at the outlet of each of the ejectors. At the outlet of the ejector, the refrigerant flow will typically be both a liquid phase and a gas phase. The gas phase will be fed back to the compressor, while the liquid phase feed passes through another expansion valve and then the evaporator. The fluid leaving the evaporator then flows to the low-pressure inlet of the ejector. The inclusion of the ejector reduces the load on the compressor because the compressor can operate with a lower pressure difference and use less energy because the ejector partially compresses the refrigerant vapor to a medium pressure level.

[0005] Existing control systems dynamically control ejectors in a multi-ejector refrigeration circuit. However, when the ejectors are operating, if the high pressure fluid and outlet fluid flow back to the secondary low pressure inlet, a large loss of compressor efficiency will result. Therefore, an improved ejector control system is desirable that optimizes machine performance while avoiding ejector backflow. Summary of the invention

[0006] This summary is provided to introduce a selection of concepts in a simplified form that are further described in the detailed description of the disclosure. This summary is not intended to identify the key or essential inventive concepts of the disclosure, nor is it intended to determine the scope of the disclosure.

[0007] A system for map interpolation-based control of multiple ejectors in an ejector refrigeration circuit is disclosed. The system includes multiple ejectors and a controller connected to each of the multiple ejectors. Each of the multiple ejectors includes a primary high-pressure input port, a secondary low-pressure input port, and an output port. The controller is adapted to generate multiple maps based on a set of predefined conditions, so that each of the multiple maps is associated with a corresponding temperature of a heat rejection heat exchanger. Next, the controller identifies a first map associated with a first temperature of the heat rejection heat exchanger and an input signal indicating a flow rate of a refrigerant fluid passing through the first ejector from the multiple maps. Next, the controller identifies a second map associated with a second temperature of the heat rejection heat exchanger from the multiple maps. Subsequently, the controller predicts an opening percentage of the first ejector from at least one of the multiple opening percentages indicated in the first map and the multiple opening percentages indicated in the second map. Finally, the controller adjusts the opening percentage of the first ejector based on the predicted opening percentage.

[0008] In one or more embodiments according to the present disclosure, the step of predicting the opening percentage includes identifying a first opening percentage from a plurality of opening percentages indicated in a first map, and identifying a second opening percentage from a plurality of opening percentages indicated in a second map. Next, the step includes performing a linear interpolation to fit a line between the identified first opening percentage and the identified second opening percentage. Next, the step of predicting the opening percentage includes identifying a slope of the line as a rate of change of a flow rate of the refrigerant fluid passing through the first ejector. Finally, when the heat rejection heat exchanger is at an intermediate temperature between the first temperature and the second temperature, the opening percentage that the first ejector will maintain is predicted based on an interpolation of the identified slope.

[0009] In one or more embodiments according to the present disclosure, each of the plurality of maps indicates a rate of change of a flow rate of refrigerant fluid passing through each of the plurality of ejectors based on a change in an opening percentage of each of the plurality of ejectors during a corresponding temperature of the heat rejection heat exchanger.

[0010] In one or more embodiments according to the present disclosure, each of the plurality of maps includes a plurality of stages, and an opening percentage of at least a first injector from the plurality of injectors is greater than zero in each of the plurality of stages.

[0011] In one or more embodiments according to the present disclosure, the plurality of stages include at least a first stage, a second stage, and a third stage. In the first stage, the opening percentages of the plurality of injectors other than the first injector are equal to zero. In the second stage, the opening percentages of the plurality of injectors other than the first injector and the second injector are equal to zero. In the third stage, the opening percentages of the plurality of injectors other than the first injector, the second injector, and the third injector are equal to zero.

[0012] In one or more embodiments according to the present disclosure, when transitioning between multiple stages of the first map, the controller is further configured to perform extrapolation to fit a line to multiple opening percentages within a predefined hysteresis band indicated in the first map. Next, the controller identifies the slope of the line as the rate of change of the flow rate of the refrigerant fluid passing through the first ejector. Subsequently, the controller predicts the opening percentages that the multiple ejectors will maintain based on interpolation of the identified slopes.

[0013] In one or more embodiments according to the present disclosure, the set of predefined conditions includes: A) The opening percentage of multiple injectors increases in one stage; B) when switching between the plurality of stages of each of the plurality of maps, the opening percentages of the plurality of ejectors are adjusted to maintain a constant flow rate of the refrigerant fluid; C) when switching between the plurality of stages in each of the plurality of maps, the opening percentage of the plurality of injectors is greater than zero; and D) A flow rate of the refrigerant fluid through the second low pressure input port of each of the plurality of ejectors is greater than zero.

[0014] In one or more embodiments according to the present disclosure, the plurality of injectors are controllable variable injectors connected in a parallel configuration.

[0015] In one or more embodiments according to the present disclosure, the ejector refrigeration circuit includes a high-pressure ejector circuit and a refrigeration evaporator flow path. The high-pressure ejector circuit includes a heat rejection heat exchanger having an inlet side and an outlet side, a plurality of ejectors, a receiver, and at least one compressor in the flow direction of the circulating refrigerant. Each of the plurality of ejectors has a main high-pressure input port, a secondary low-pressure input port, and an output port, so that the main high-pressure input port is in fluid communication with the outlet side of the heat rejection heat exchanger. The receiver includes an inlet, a liquid outlet, and a gas outlet. The inlet is in fluid communication with the output port of each of the plurality of ejectors. At least one compressor includes an inlet side and an outlet side. The inlet side of at least one compressor is in fluid communication with the gas outlet of the receiver, and the outlet side of at least one compressor is in fluid communication with the inlet side of the heat rejection heat exchanger. The refrigeration evaporator flow path includes a liquid pump, at least one refrigeration expansion device, and at least one refrigeration evaporator in the flow direction of the circulating refrigerant. The liquid pump includes an inlet side and an outlet side, so that the inlet side is in fluid communication with the liquid outlet of the receiver. At least one refrigeration expansion device includes an inlet side and an outlet side. The inlet side of at least one refrigeration expansion device is in fluid communication with the outlet side of the liquid pump. The at least one refrigeration evaporator includes an inlet side and an outlet side. The inlet side is in fluid communication with the outlet side of the at least one refrigeration expansion device, and the outlet side is in fluid communication with the secondary low pressure input port of each of the plurality of ejectors.

[0016] In one or more embodiments according to the present disclosure, the liquid pump includes a bypass line having a switchable bypass valve for allowing the refrigerant to selectively bypass the liquid pump by opening the switchable bypass valve.

[0017] A method for map interpolation-based control of multiple ejectors in an ejector refrigeration circuit is also disclosed. The method includes generating multiple maps via a controller based on a set of predefined conditions, each of the multiple maps being associated with a corresponding temperature of a heat rejection heat exchanger. Next, the controller identifies a first map associated with a first temperature of the heat rejection heat exchanger and an input signal indicating a flow rate of a refrigerant fluid passing through the first ejector from the multiple maps. Next, the controller identifies a second map associated with a second temperature of the heat rejection heat exchanger from the multiple maps. Next, the controller predicts an opening percentage of the first ejector from at least one of the multiple opening percentages indicated in the first map and the multiple opening percentages indicated in the second map. Finally, the controller adjusts the opening percentage of the first ejector based on the predicted opening percentage.

[0018] In one or more embodiments according to the present disclosure, the step of predicting the opening percentage includes identifying a first opening percentage from a plurality of opening percentages indicated in a first map, and identifying a second opening percentage from a plurality of opening percentages indicated in a second map. Next, the step includes performing a linear interpolation to fit a line between the identified first opening percentage and the identified second opening percentage. Next, the step of predicting the opening percentage includes identifying a slope of the line as a rate of change of a flow rate of the refrigerant fluid passing through the first ejector. Finally, when the heat rejection heat exchanger is at an intermediate temperature between the first temperature and the second temperature, the opening percentage that the first ejector will maintain is predicted based on an interpolation of the identified slope.

[0019] In one or more embodiments according to the present disclosure, each of the plurality of maps indicates a rate of change of a flow rate of refrigerant fluid passing through each of the plurality of ejectors based on a change in an opening percentage of each of the plurality of ejectors during a corresponding temperature of the heat rejection heat exchanger.

[0020] In one or more embodiments according to the present disclosure, each of the plurality of maps includes a plurality of stages, and an opening percentage of at least a first injector from the plurality of injectors is greater than zero in each of the plurality of stages.

[0021] In one or more embodiments according to the present disclosure, the plurality of stages include at least a first stage, a second stage, and a third stage. In the first stage, the opening percentages of the plurality of injectors other than the first injector are equal to zero. In the second stage, the opening percentages of the plurality of injectors other than the first injector and the second injector are equal to zero. In the third stage, the opening percentages of the plurality of injectors other than the first injector, the second injector, and the third injector are equal to zero.

[0022] In one or more embodiments according to the present disclosure, when transitioning between multiple stages of the first map, the controller is further configured to perform extrapolation to fit a line to multiple opening percentages within a predefined hysteresis band indicated in the first map. Next, the controller is configured to identify the slope of the line as the rate of change of the flow rate of the refrigerant fluid passing through the first ejector. Subsequently, the controller is configured to predict the opening percentages that the multiple ejectors will maintain based on interpolation of the identified slopes.

[0023] In one or more embodiments according to the present disclosure, the group of predefined conditions includes: A) The opening percentage of multiple injectors increases in one stage; B) when switching between the plurality of stages of each of the plurality of maps, the opening percentages of the plurality of ejectors are adjusted to maintain a constant flow rate of the refrigerant fluid; C) when switching between the plurality of stages in each of the plurality of maps, the opening percentage of the plurality of injectors is greater than zero; and D) A flow rate of the refrigerant fluid through the second low pressure input port of each of the plurality of ejectors is greater than zero.

[0024] In one or more embodiments according to the present disclosure, each of the plurality of ejectors includes a primary high-pressure input port, a secondary low-pressure input port, and an output port.

[0025] In one or more embodiments according to the present disclosure, the ejector refrigeration circuit includes a high-pressure ejector circuit and a refrigeration evaporator flow path. The high-pressure ejector circuit includes a heat rejection heat exchanger having an inlet side and an outlet side, a plurality of ejectors, a receiver, and at least one compressor in the flow direction of the circulating refrigerant. Each of the plurality of ejectors has a main high-pressure input port, a secondary low-pressure input port, and an output port, so that the main high-pressure input port is in fluid communication with the outlet side of the heat rejection heat exchanger. The receiver includes an inlet, a liquid outlet, and a gas outlet. The inlet is in fluid communication with the output port of each of the plurality of ejectors. At least one compressor includes an inlet side and an outlet side. The inlet side of at least one compressor is in fluid communication with the gas outlet of the receiver, and the outlet side of at least one compressor is in fluid communication with the inlet side of the heat rejection heat exchanger. The refrigeration evaporator flow path includes a liquid pump, at least one refrigeration expansion device, and at least one refrigeration evaporator in the flow direction of the circulating refrigerant. The liquid pump includes an inlet side and an outlet side, so that the inlet side is in fluid communication with the liquid outlet of the receiver. At least one refrigeration expansion device includes an inlet side and an outlet side. The inlet side of at least one refrigeration expansion device is in fluid communication with the outlet side of the liquid pump. The at least one refrigeration evaporator includes an inlet side and an outlet side. The inlet side is in fluid communication with the outlet side of the at least one refrigeration expansion device, and the outlet side is in fluid communication with the secondary low pressure input port of each of the plurality of ejectors.

[0026] In one or more embodiments according to the present disclosure, the liquid pump includes a bypass line having a switchable bypass valve, allowing the refrigerant to selectively bypass the liquid pump by opening the switchable bypass valve.

[0027] In order to further clarify the advantages and features of the methods, systems and devices, a more particular description of the methods, systems and devices will be presented by reference to their specific embodiments shown in the accompanying drawings. It is recognized that these figures only depict typical embodiments of the present disclosure and therefore will not be considered to limit its scope. The present disclosure will be described and explained with additional particularity and detail in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings, in which like numerals represent like parts throughout the figures, and in which:

[0029] Figure 1A A schematic diagram exemplarily illustrates a system for map interpolation-based control of a plurality of ejectors in an ejector refrigeration circuit according to one or more embodiments of the present disclosure;

[0030] Figure 1B By way of example Figure 1A A schematic cross-sectional view of a controllable injector employed in an exemplary embodiment shown in FIG.

[0031] Figure 2A By way of example, Figure 1A A schematic diagram of multiple maps generated by a controller of the system shown in;

[0032] Figure 2B As shown by way of example Figure 1A Schematic diagram of a map interpolation method implemented between a first map associated with a first temperature of a heat rejection heat exchanger and a second map associated with a second temperature of the heat rejection heat exchanger generated by a controller of the system shown in FIG.

[0033] Figure 2C By way of example, the use of Figure 1A A schematic diagram of a phase switching method for generating a first map associated with a first temperature of a heat rejection heat exchanger by a controller of the system shown in FIG.

[0034] Figure 3 A flow chart indicating a method for map interpolation based control of a plurality of ejectors in an ejector refrigeration circuit is exemplarily shown.

[0035] Furthermore, the skilled artisan will recognize that the elements in the figures are shown for simplicity and may not necessarily be drawn to scale. For example, a flow chart shows a method in terms of the most prominent steps involved to help improve understanding of aspects of the present disclosure. Furthermore, with respect to the construction of a device, one or more components of the device may be represented in the figures with conventional symbols, and the figures may show only those specific details relevant to understanding the embodiments of the present disclosure, lest the figures be obscured by details that would be readily apparent to those skilled in the art having the benefit of the description herein. DETAILED DESCRIPTION

[0036] To facilitate an understanding of the principles of the present disclosure, reference will now be made to various embodiments, and specific language will be used to describe the various embodiments. It will be understood, however, that no limitation of the scope of the present disclosure is thereby intended, and such changes and further modifications in the illustrated systems, and such further applications of the principles of the present disclosure as illustrated herein are contemplated as would normally occur to one skilled in the art to which the present disclosure relates.

[0037] Those skilled in the art will appreciate that the foregoing general description and the following detailed description are illustrative of the present disclosure and are not intended to be restrictive thereof.

[0038] Reference throughout this specification to "aspect," "another aspect," or similar language means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Thus, appearances of the phrases "in an embodiment," "in another embodiment," "some embodiments," "one or more embodiments," and similar language throughout this specification may (but do not necessarily) all refer to the same embodiment.

[0039] The terms "include", "comprises" or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process or method that includes a series of steps includes not only those steps but may also include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or subsystems or elements or structures or components beginning with "includes..." do not exclude the presence of other devices or other subsystems or other elements or other structures or other components, or additional devices or additional subsystems or additional elements or additional structures or additional components without more limitations.

[0040] Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0041] Figure 1A A schematic diagram of a system 100 for map interpolation-based control of a plurality of ejectors 101 in an ejector refrigeration circuit according to one or more embodiments of the present disclosure is exemplarily shown. It can be appreciated that the components of the system 100 are described in the detailed description of FIG. 1 , and the algorithm or process flow of the map interpolation-based control of the plurality of ejectors 101 is described in FIG. Figure 2B Described in the detailed description.

[0042] In an exemplary embodiment according to the present disclosure, the ejector refrigeration circuit includes a high-pressure ejector circuit, which includes a heat rejection heat exchanger 105, a plurality of ejectors 101, a receiver 106, and at least one compressor 107 in the flow direction of the circulating refrigerant. The ejector refrigeration circuit also includes a refrigeration evaporator flow path, which includes a liquid pump 108, at least one refrigeration expansion device 109, and at least one refrigeration evaporator 110 in the flow direction of the circulating refrigerant.

[0043] The heat rejection heat exchanger 105 includes an inlet side 105a and an outlet side 105b. The heat rejection heat exchanger 105 can also be interchangeably referred to as a gas cooler unit or a condenser. The heat rejection heat exchanger 105 is configured to transfer heat from the refrigerant to the environment, thereby reducing the overheating of the refrigerant. In an embodiment, the heat rejection heat exchanger 105 may include one or more fans for blowing air through the heat rejection heat exchanger 105 to enhance the heat transfer from the refrigerant to the environment. The type and number of fans used can be adjusted based on the type of condenser used, etc. The cooled refrigerant leaving the heat rejection heat exchanger 105 at the outlet side 105b is delivered to the main high pressure input port 101a of the plurality of ejectors 101 via a high pressure input line and an optional service valve.

[0044] A plurality of ejectors 101 are adapted to expand the refrigerant to a reduced intermediate pressure level. Each of the plurality of ejectors 101 includes a primary high pressure input port 101a, a secondary low pressure input port 101b, and an output port 101c. The primary high pressure input port 101a is in fluid communication with the outlet side 105b of the heat rejection heat exchanger 105. The expanded refrigerant leaves the ejector 101 through the corresponding ejector output port 101c and is delivered to the inlet 106a of the receiver 106. In addition, the receiver 106 includes a liquid outlet 106b and a gas outlet 106c, and the inlet 106a is in fluid communication with the output port 101c of each of the plurality of ejectors 101. In the receiver 106, the refrigerant is separated into a liquid portion collected at the bottom of the receiver 106 and a gas phase portion collected in the upper portion of the receiver 106 by gravity. The gas phase portion of the refrigerant leaves the receiver 106 through a gas outlet 106c provided at an upper portion of the receiver 106 and is delivered to an inlet side 107a of at least one compressor 107, completing the refrigerant cycle of the high-pressure ejector circuit.

[0045] The at least one compressor 107 includes an inlet side 107a and an outlet side 107b. The inlet side 107a of the at least one compressor 107 is in fluid communication with the gas outlet 106c of the receiver 106 and the outlet side 107b of the at least one compressor 107 is in fluid communication with the inlet side 105a of the heat rejection heat exchanger 105.

[0046] The liquid pump 108 includes an inlet side 108a and an outlet side 108b. The inlet side 108a is in fluid communication with the liquid outlet 106b of the receiver 106. In an embodiment, the liquid pump 108 may be located below the receiver 106. Arranging the liquid pump 108 below the receiver 106 allows the liquid refrigerant to be supplied from the receiver 106 to the inlet side 108a of the liquid pump 108 using gravity. The liquid pump 108 also includes a bypass line, which includes a switchable bypass valve 111, allowing the refrigerant to selectively bypass the liquid pump 108 by opening the switchable bypass valve 111. In an embodiment, a separate liquid pump 108 and (optional) bypass line may be provided, allowing the pressure of the liquid refrigerant to be independently adjusted.

[0047] At least one refrigeration expansion device 109 includes an inlet side 109a and an outlet side 109b. The inlet side 109a of the at least one refrigeration expansion device 109 is in fluid communication with the outlet side 108b of the liquid pump 108. At least one refrigeration evaporator 110 includes an inlet side 110a and an outlet side 110b. The inlet side 110a is in fluid communication with the outlet side 109b of the at least one refrigeration expansion device 109, and the outlet side 110b is in fluid communication with the secondary low pressure input port 101b of each of the plurality of ejectors 101.

[0048] The system 100 includes a controller 104 coupled to each of a plurality of injectors 101 having a primary high pressure input port 101a, a secondary low pressure input port 101b, and an output port 101c. In an embodiment, each of the plurality of injectors 101 is a controllable variable injector 101, such as Figure 1B Hereinafter, the "injector 101" may be interchangeably referred to as a "controllable variable injector 101". In addition, a plurality of injectors 101 may be connected in parallel to each other or in a parallel configuration.

[0049] The plurality of injectors 101 may have different capacities, or may all have the same capacity. In another embodiment, a first group of injectors 101 from the plurality of injectors 101 may have equal capacities, and a second group of injectors 101 from the plurality of injectors 101 may have equal capacities, such that the capacity of the second group is greater than the capacity of the first group of injectors 101. In yet another embodiment, a first group of injectors 101 from the plurality of injectors 101 may have equal capacities, and a second group of injectors 101 from the plurality of injectors 101 may have equal capacities, such that the capacity of the first group is greater than the capacity of the second group of injectors 101.

[0050] If the plurality of injectors 101 used are controllable variable injectors 101, the plurality of injectors 101 may have an opening percentage that can be adjusted by actuating the needles 126 ( Figure 1B As used herein, the term "opening percentage" is used to adjust Figure 1B Detailed description of the invention. Alternatively, each of the plurality of ejectors 101 used may be a controllable variable ejector 101 having a flow valve 112 upstream of the sub-low pressure input port 101b. In an embodiment, the controller 104 is adapted to open the flow valve 112 to allow refrigerant flow, and is adapted to close the flow valve 112 to prevent refrigerant flow. In such implementations, the controller 104 actuates the flow valve 112 between the ON and OFF positions to allow or prevent refrigerant flow toward the sub-low pressure input port 101b of the corresponding ejector 101.

[0051] As used herein, the “controller 104” may be configured to control at least one compressor 107, a liquid pump 108, a flow valve 112, and / or a plurality of ejectors 101 (if at least one of the plurality of ejectors 101 is variable). The controller 104 is adapted to control at least one compressor 107, a liquid pump 108, a flow valve 112, and / or a plurality of ejectors 101 (if at least one of the plurality of ejectors 101 is variable). Figure 2A-2C The multiple ejectors 101 are controlled by using the multiple generated maps described in detail in the detailed description of the ejector refrigeration circuit, so as to improve the coefficient of performance (COP) of the ejector refrigeration circuit as efficiently as possible. In an embodiment, the controller 104 may refer to a single controller 104, or may be configured to include one or a combination of a microprocessor, suitable logic, circuit, printed circuit board (PCB), audio interface, visual interface, tactile interface, etc. The controller 104 may include, but is not limited to, a microcontroller, a reduced instruction set computing (RISC) processor, an application specific integrated circuit (ASIC) processor, a complex instruction set computing (CISC) processor, a central processing unit (CPU), a graphics processing unit (GPU), a state machine, and / or other processing units or circuits.

[0052] The controller 104 may also include suitable logic, circuitry, interfaces and / or code that may be configured to execute the groups of instructions stored in the memory unit. In an exemplary implementation of the memory unit according to the present disclosure, the memory unit may include, but is not limited to, an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), a read-only memory (ROM), a hard disk drive (HDD), a flash memory, a solid-state drive (SSD), and / or a CPU cache memory.

[0053] The controller 104 may also include a communication unit suitable for communicating with the computing device via a communication network. The communication unit may be composed of, for example, a telematics transceiver (DCM), a distress battery, a GPS, a data communication module ASSY, a telephone microphone ASSY, and a telephone antenna ASSY. The communication network may include, but is not limited to, a wide area network (WAN), a cellular network (such as a 3G, 4G, or 5G network), an Internet-based mobile ad hoc network (IMANET), and the like. The communication network may also include wired media (such as a wired network or a direct wired connection) and wireless media (such as acoustic, radio frequency (RF), microwave, infrared (IR), and other wireless media). In an embodiment, the computing device may be implemented as part of a small portable (or mobile) electronic device (such as a mobile phone, a personal data assistant (PDA), a personal media player device, a wireless network monitoring device, a personal headset device, a specific application device, or a hybrid device including any of the above functions).

[0054] In an exemplary embodiment, the controller 104 may receive power from a suitably coupled power source (not shown). For example, a battery or power source may be electrically coupled to supply electrical power to the controller 104. In an embodiment, the power source may be, for example, a battery, such as a rechargeable battery or a non-rechargeable battery. Examples of suitable batteries include, for example, lithium batteries (such as lithium-ion batteries), nickel batteries (such as nickel-cadmium batteries), and alkaline batteries.

[0055] Figure 1B A schematic cross-sectional view of a variable control injector 101 is shown as an example, as it can be used in Figure 1AIn the exemplary embodiment shown in . Each of the multiple ejectors 101 includes a main high-pressure input port 101a, a secondary low-pressure input port 101b and an output port 101c. The ejector 101 is formed by a power nozzle 113 nested in an external component 114. The main high-pressure input port 101a forms an inlet to the power nozzle 113. The outlet of the external component 114 provides an output port 101c of the ejector 101. The main refrigerant flow 115 enters the main high-pressure input port 101a, and then enters the convergent section 116 of the power nozzle 113. Then, the main refrigerant flow 115 passes through the throat section 117 and the divergent expansion section 118 to the outlet 119 of the power nozzle 113. The power nozzle 113 accelerates the main refrigerant flow 115 and reduces the pressure of the main refrigerant flow 115. The secondary low-pressure input port 101b forms the inlet of the external component 114. The pressure drop caused by the power nozzle 113 to the main flow draws the secondary flow 120 into the outer part 114. The outer part 114 includes a mixer having a convergent section 121 and an elongated throat or mixing section 122. The outer part 114 also has a divergent section or diffuser 123 downstream of the elongated throat or mixing section 122. The outlet 119 of the power nozzle 113 is positioned within the convergent section 121. When the main refrigerant flow 115 leaves the outlet 119, the main refrigerant flow 115 begins to mix with the secondary flow 120, wherein further mixing occurs through the elongated throat or mixing section 122 that provides a mixing zone. Therefore, the corresponding main flow path and the secondary flow path extend from the main high pressure input port 101a and the secondary low pressure input port 101b to the output port 101c, respectively, and merge at the outlet.

[0056] In operation, the primary refrigerant stream 115 may be supercritical when entering the variable ejector 101 and subcritical when leaving the motive nozzle 113. The secondary stream 120 may be gaseous or a mixture of gas and a smaller amount of liquid when entering the secondary low pressure input port 101b. The resulting combined stream 124 is a liquid / vapor mixture and is decelerated and restored in pressure in the diffuser 123 while maintaining the mixture.

[0057] The controllability of the controllable variable ejector 101 is provided by a needle valve 125 having a needle 126 and an actuator 127. The actuator 127 is adapted to move the end portion 128 of the needle 126 into and out of the throat section 117 of the power nozzle 113 to adjust the main refrigerant flow 115 through the power nozzle 113, and thereby adjust the entire controllable variable ejector 101. In an embodiment, each of the plurality of ejectors 101 may have a throat section 117 with a different diameter. Alternatively, each of the plurality of ejectors 101 may have a throat section 117 with an equal diameter. As used throughout this document, the term "opening percentage" refers to the percentage of opening of the throat section 117. When the end portion 128 of the needle 126 moves into the throat section 117, the opening percentage is reduced to zero percent. Similarly, when the end portion 128 is completely moved out of the throat section 117, the opening percentage increases to 100%. Therefore, by actuating the tip portion of the needle 126 into and out of the throat section 117 of the motive nozzle 113 , the opening percentage of the throat section 117 is controlled to range between 0-100%, such that an opening percentage of zero fully restricts the main refrigerant flow 115 , and an opening percentage of 100% fully allows the main refrigerant flow 115 .

[0058] In an embodiment, the actuator 127 may be an electric actuator, such as a solenoid or the like. Figure 1A The controller 104 disclosed in the detailed description of the can be connected to the actuator 127 and other controllable components of the controllable variable ejector 101 using hard wire or wireless communication paths. The controller 104 can store mathematical models to estimate the suction and motive flow rates. In this regard, the controller 104 can extract signals from sensors such as temperature sensors, pressure sensors, etc. to determine one or more parameters for use in the mathematical model. For example, the controller uses motive pressure, motive temperature, diameter of the ejector needle opening, diffuser pressure, suction pressure, etc. to dynamically estimate the suction flow rate and motive flow rate during operation.

[0059] Figure 2A By way of example, Figure 1A Schematic diagram of a plurality of maps 200, 200A, 200B, 200C generated by a controller 104 of the system 100 is shown in FIG. The controller 104 is coupled to each of the plurality of injectors 101 of the system 100. As an example, the controller 104 is shown to generate the maps 200, 200A, 200B, and 200C based on a set of predefined conditions.

[0060] Each of the maps 200, 200A, 200B, 200C includes a plurality of phases 201, 202, 203. For example, in the first phase 201, only the first injector 101' is turned on. In the second phase 202, the first injector 101' and the second injector 101" are turned on. In the third phase 203, the first injector 101', the second injector 101" and the third injector 101"' are turned on. The number of phases 201, 202, 203 may be the same as the number of injectors 101. Figure 2B As shown in , in the illustrated embodiment, three stages 201, 202, 203 are depicted with respect to three injectors 101', 101", 101'". It can be appreciated that the number of injectors 101 can be two, three, more than three, or in extreme cases only one. In this regard, the number of stages can also include two stages, three stages, or in extreme cases a single stage. Therefore, the number of stages is equal to the number of injectors.

[0061] In an embodiment, the set of predefined conditions may be a set of constraints, which at least include the following: (A) The opening percentages of the plurality of injectors 101 are increased in one stage. This means that the opening percentages of the plurality of injectors 101 cannot be decreased in one stage. (b) When switching between the multiple stages 201, 202, 203 of each of the multiple maps 200, 200A, 200B, 200C, the opening percentage of the multiple ejectors 101 is adjusted to keep the flow rate of the refrigerant fluid constant. This means that regardless of the number of ejectors 101 that are closed or opened, the cumulative refrigerant fluid leaving the multiple ejectors 101 can be kept constant. (c) when switching between the plurality of phases 201, 202, 203 of each of the plurality of maps 200, 200A, 200B, 200C, the opening percentage of the plurality of injectors 101 is greater than zero. This means that once an injector 101 from the plurality of injectors 101 is opened during any phase, the same injector 101 may not be closed in any subsequent phase; and (d) The flow rate of the refrigerant fluid passing through the second low-pressure input port 101 b of each of the plurality of ejectors 101 is greater than zero.

[0062] In an embodiment, each of the plurality of maps 200, 200A, 200B, 200C is associated with a corresponding temperature of the heat rejection heat exchanger 105. For example, the map 200 is generated for a temperature of 277.1K of the heat rejection heat exchanger 105, the map 200A is generated for a temperature of 289.1K of the heat rejection heat exchanger 105, the map 200B is generated for a temperature of 301.1K of the heat rejection heat exchanger 105, the map 200C is generated for a temperature of 313.1K of the heat rejection heat exchanger 105, etc. Each of the plurality of maps 200, 200A, 200B, 200C indicates a rate of change of a flow rate of the refrigerant fluid passing through each of the plurality of ejectors 101 based on a change in an opening percentage of each of the plurality of ejectors 101 during a corresponding temperature of the heat rejection heat exchanger 105.

[0063] Each of the plurality of maps 200, 200A, 200B, 200C comprises a plurality of phases 201, 202, 203. During the first phase 201, only the opening percentage of the first injector 101' is greater than zero. This means that the first injector 101' is open, while the second injector 101" and the third injector 101"' remain closed. During the second stage 202, the opening percentage of the plurality of injectors 101 other than the first injector 101' and the second injector 101" is equal to zero. This means that the first injector 101' and the second injector 101" are opened, while the third injector 101"' remains closed. Similarly, during the third stage 203, the opening percentage of the plurality of injectors 101 other than the first injector 101', the second injector 101", and the third injector 101"' is equal to zero. This means that the first injector 101', the second injector 101", and the third injector 101"' are opened, while any remaining injectors are closed. Therefore, in each of the maps 200, 200a, 200b, 200c, in each of the plurality of stages 201, 202, 203, the opening percentage of at least the first injector 101' from the plurality of injectors 101 is greater than zero.

[0064] As an example, when the temperature of the heat rejection heat exchanger 105 reaches 289.1K, the controller 104 identifies the first map 200A from the plurality of maps 200, 200A, 200B, 200C. The controller 104 also receives an input signal indicating the flow rate of the refrigerant fluid passing through the first ejector 101' from the first ejector 101'. The controller 104 adjusts the opening percentages of the plurality of ejectors 101 based on the identified first map 200A.

[0065] Figure 2B A schematic diagram of a spectrum interpolation method implemented between the first spectrum 200A and the second spectrum 200B is exemplarily shown. In the spectrum interpolation method, Figure 1AAn interpolation line L is drawn between a first map 200A associated with a first temperature GCT′ of the heat rejection heat exchanger 105 and a second map 200B associated with a second temperature GCT″ of the heat rejection heat exchanger 105 generated by the controller 104 of the system 100 shown in FIG. Figure 2B The embodiments disclosed in show linear curves, but the plurality of graphs 200, 200A, 200B, and 200C may include non-linear curves without departing from the scope of the present disclosure.

[0066] like Figure 2A As has been described in , the controller 104 is shown to generate the maps 200, 200A, 200B, and 200C based on a set of predefined conditions. During operation of the system 100, the temperature of the heat rejection heat exchanger 105 increases or decreases, and the map corresponding to the instantaneous temperature is identified and selected accordingly. For example, when the heat rejection heat exchanger 105 is at a temperature of 277.1K, the map 200 generated for the 277.1K temperature of the heat rejection heat exchanger 105 is selected. Similarly, when the heat rejection heat exchanger 105 is at a temperature of 289.1K, the map 200A generated for the 289.1K temperature of the heat rejection heat exchanger 105 is selected, and when the heat rejection heat exchanger 105 is at a temperature of 301.1K, the map 200B generated for the 301.1K temperature of the heat rejection heat exchanger 105 is selected, and so on.

[0067] Existing systems utilize algorithms that implement discrete switching between maps for different temperatures of the heat rejection heat exchanger 105, causing possible oscillations and system instability. This means that, for example, if the temperature of the heat rejection heat exchanger 105 increases from 277.1K to 289.1K, the opening percentage of the plurality of ejectors 101 that are open may change abruptly based on the identified opening percentage according to the map 200A. The proposed algorithm or steps performed by the controller 104 anticipate or predict the opening percentage of the plurality of ejectors 101 based on the map associated with the instantaneous temperature of the heat rejection heat exchanger 105. In this regard, the system 100 provides smooth transitions between the maps 200, 200A, 200B, 200C, etc. for different temperatures, avoiding any discontinuous behavior.

[0068] In an embodiment, the controller 104 is coupled to each of the plurality of injectors 101, such as Figure 1A Each of the plurality of injectors 101 may include Figure 1B In addition, the controller 104 is suitable for Figure 2AThe plurality of maps 200 , 200A, 200B, 200C, etc. may be generated based on the set of predefined conditions described in the detailed description of FIG. Each of the plurality of maps 200 , 200A, 200B, 200C may be associated with a corresponding temperature of the heat rejection heat exchanger 105 .

[0069] When the temperature of the heat rejection heat exchanger 105 begins to change, the controller 104 identifies a first map, such as 200A, from the plurality of maps 200, 200A, 200B, 200C, associated with a first temperature GCT' of the heat rejection heat exchanger 105 and an input signal indicating the flow rate of the refrigerant fluid passing through the first ejector 101'. The first temperature may be 289.1K and may be an instantaneous temperature of the heat rejection heat exchanger 105 from which the temperature changes to a second temperature GCT" of 301.1K. When the heat rejection heat exchanger 105 is at an intermediate temperature GCT"' between the first temperature GCT' and the second temperature GCT", the controller 104 dynamically predicts an intermediate opening percentage OD"' between the known opening percentage OD' associated with the first map 200A and the known opening percentage OD" associated with the second map 200B.

[0070] When the heat rejection heat exchanger is at an intermediate temperature GCT"' between the first temperature GCT' and the second temperature GCT", the controller 104 predicts the intermediate opening percentage OD"' of the first ejector 101' from the plurality of opening percentages indicated in the second map. Finally, before the heat rejection heat exchanger 105 reaches the second temperature 289.1K, the controller 104 adjusts the opening percentage of the first ejector 101' based on the predicted opening percentage. It can be appreciated that although the steps mentioned in the present disclosure are described with respect to the "first ejector 101'", the steps disclosed herein may be implemented by any of the remaining plurality of ejectors 101 of the system 100.

[0071] The step of predicting the opening percentage includes identifying a first opening percentage from a plurality of opening percentages indicated in the first map 200A, and identifying a second opening percentage from a plurality of opening percentages indicated in the second map 200B. Next, the step includes performing linear interpolation to fit a line L between the identified first opening percentage and the identified second opening percentage. Next, the controller 104 identifies the slope of the line L as the rate of change of the flow rate of the refrigerant fluid passing through the first ejector 101'. Finally, the controller 104 predicts the opening percentage OD"' that the first ejector 101' will maintain when the heat rejection heat exchanger 105 is at the intermediate temperature GCT"' based on the interpolation of the identified slope.

[0072] Figure 2C By way of example, the use of Figure 1ASchematic diagram of a phase switching method of a first map 200A associated with a first temperature GCT′ of a heat rejection heat exchanger 105 generated by the controller 104 of the system 100 shown in FIG. Figure 2C As shown in FIG. 2 , the graph 200A includes a plurality of stages 201 , 202 , 203 . Figure 2C A second scenario is shown where the system 100 switches between stages 202 and 203. For example, in stage 202, which is the second stage, the first injector 101' and the second injector 101" are open. When the system 100 transitions from the second stage 202 to the third stage 203, the third injector 101"' becomes open. During this transition, sometimes the system 100 falls back to the second stage 202 within the predefined hysteresis band H. If the system 100 falls back to the second stage 202, to a region outside the predefined hysteresis band H, the system 100 remains in the second stage 202. Alternatively, if the system 100 is in the third stage 203 and transitions to the second stage 202, the system 100 is initially at point 1 and transitions to point 3 in the second stage 202. Now, the system 100 attempts to fall back to point 2, triggering a phase switch to the third phase 203, but because the system 100 is still within the predefined hysteresis band H, the system 100 remains in the second phase 202, reaching point 4 by extrapolating phase 202. The system 100 remains in the second phase 202 until the system 100 crosses point 5 of the predefined hysteresis band H. When the system 100 is at point 6, the system 100 fully crosses into the third phase 203.

[0073] However, if the system 100 is within the predefined hysteresis band H, the controller 104 is further configured to perform an extrapolation to fit the line L' to a plurality of opening percentages within the predefined hysteresis band H indicated in the first map 200A. Next, if the phase switch is between the second phase 202 and the third phase 203 (e.g. Figure 2C), the controller 104 identifies the slope of the line L' as the rate of change of the flow rate of the refrigerant fluid passing through the first ejector 101'. Finally, the controller 104 predicts the percentage of opening that the first ejector 101' will maintain based on the interpolation of the identified slope. Alternatively, if the system 100 stays within the predefined hysteresis band H and moves backward in the direction of stage 203, the controller 104 is further configured to perform an extrapolation of stage 202. Next, the controller 104 identifies the opening of the first ejector 101' to the right of the predefined hysteresis band H based on the performed extrapolation. Finally, when the system 100 exceeds the right band of the predefined hysteresis band H, the controller 104 stops extrapolating the second stage 202, performs a stage switch to the third stage 203, and adjusts the percentage of opening of the first ejector 101' to match the percentage of opening defined by the third stage 203. Furthermore, during phase switching, implementation of a predefined hysteresis band H makes the system 100 more robust during phase switching and in anticipation of jumps in high voltage. In certain implementations of the present disclosure, the predefined hysteresis band H may be user defined.

[0074] It can be recognized that although Figure 2C The embodiments disclosed in 200, 200A, 200B, and 200C show linear curves, but each of the stages 201, 202, 203 of the plurality of graphs 200, 200A, 200B, and 200C may include nonlinear curves without departing from the scope of the present disclosure. In such embodiments, different types of extrapolation methods may be used to predict the opening percentage when the system 100 switches between different stages (e.g., 201, 202, 203, etc.). Therefore, in such embodiments, the system 100 extrapolates the opening percentage within a predefined hysteresis band H. In this regard, extrapolation methods known in the art that facilitate prediction of the opening percentage during stage switching (e.g., but not limited to, linear extrapolation methods, polynomial extrapolation methods, conical extrapolation methods, etc.) fall within the scope of the present disclosure.

[0075] Figure 3 A flow chart is shown by way of example indicating a method 300 for map interpolation based control of a plurality of ejectors 101 in an ejector refrigeration circuit. Figure 3 The steps are shown and described in a particular order, but the steps may appear in a variation of the order according to various embodiments of the present disclosure. In addition, for the sake of brevity, the steps have been described in detail in relation to Figure 1A -2 The descriptions related to Figure 3 Details related to the various steps in the method are not discussed in detail herein. A method 300 for controlling a plurality of ejectors in an ejector refrigeration circuit is disclosed.

[0076] At step 301, the controller 104 performs the following operations based on Figure 2A2 to generate a plurality of maps 200, 200A, 200B, 200C as shown in FIG. 2 . Each of the plurality of maps 200, 200A, 200B, 200C is associated with a corresponding temperature of the heat rejection heat exchanger 105. Generating the plurality of maps 200, 200A, 200B, 200C for different temperatures of the heat rejection heat exchanger 105 ensures that the ejector control is optimized over the entire operating range of the heat rejection heat exchanger 105.

[0077] At step 303, the controller 104 identifies a first map 200 from the plurality of maps 200, 200A, 200B, 200C that is associated with a first temperature of the heat rejection heat exchanger 105 (e.g., 277.1K) and an input signal from the first ejector 101' indicative of a flow rate of the refrigerant fluid passing through the first ejector 101'. This feature advantageously allows the ejector control to be adjusted based on changes in the temperature of the heat rejection heat exchanger 105. This means that any fluctuations or changes in the temperature of the heat rejection heat exchanger 105 will not adversely affect the ejector control of the system 100.

[0078] At step 305 , the controller 104 identifies a second map 200A from the plurality of maps 200 , 200A, 200B, 200C that is associated with a second temperature (eg, 289.1 K) of the heat rejection heat exchanger 105 .

[0079] At step 307 , when the heat rejection heat exchanger 105 is at an intermediate temperature between the first temperature and the second temperature, the controller 104 predicts the opening percentage of the first ejector from the plurality of opening percentages indicated in the first map 200A and the plurality of opening percentages indicated in the second map 200A.

[0080] In an embodiment, the step of predicting the opening percentage is included in a map interpolation method, first, identifying a first opening percentage from a plurality of opening percentages indicated in the first map 200A, and identifying a second opening percentage from a plurality of opening percentages indicated in the second map 200B. Second, the step of predicting the opening percentage includes performing a linear interpolation to fit a line L between the identified first opening percentage and the identified second opening percentage. Next, the controller identifies the slope of the line L as the rate of change of the flow rate of the refrigerant fluid passing through the first ejector 101'. Finally, the controller 104 predicts the opening percentage that the first ejector 101' will maintain when the heat rejection heat exchanger 105 is at an intermediate temperature based on the interpolation of the identified slopes.

[0081] In an embodiment, when transitioning between multiple phases (e.g., 201, 202, 203, etc. of the first map 200A) using the phase switching method, the predicting step includes the controller 104 being configured to perform extrapolation to fit a line L' to multiple opening percentages within a predefined hysteresis band H indicated in the first map 200A. Next, the controller 104 identifies the slope of the line as the rate of change of the flow rate of the refrigerant fluid passing through the first ejector 101'. Subsequently, the controller 104 predicts the opening percentages that the multiple ejectors 101', 101", 101'" will maintain based on interpolation of the identified slopes.

[0082] At step 309 , before the heat rejection heat exchanger 105 reaches the second temperature, the controller 104 adjusts the opening percentage of the first ejector 101 ′ based on the predicted opening percentage.

[0083] The system 100 disclosed herein ensures that the overall machine behavior is more robust by minimizing the number of on / off switches. This is because the set of predefined conditions includes the constraint that the injector 101' opened in the first stage 201 cannot be closed in the subsequent stage 202 or 203. In addition, within a stage, the opening percentage of the injector 101 always increases. In addition, during the stage switching, when a jump in the high pressure is expected, the implementation of the predefined hysteresis band H makes the system 100 more robust by reducing the number of stage switching (i.e., opening jumps).

[0084] Although specific language is used to describe the subject matter, it is not intended to produce any limitation therefrom. As will be apparent to those skilled in the art, various work modifications may be made to the method in order to implement the creative conception as taught herein. The figure and the foregoing description provide examples of embodiments. Those skilled in the art will recognize that one or more of the elements described may be well combined into a single functional element. Alternatively, some elements may be divided into a plurality of functional elements. Elements from one embodiment may be added to another embodiment.

Claims

1. A system for map interpolation-based control of a plurality of ejectors in an ejector refrigeration circuit, the system comprising: a plurality of injectors, each of the plurality of injectors having a primary high pressure input port, a secondary low pressure input port, and an output port; as well as a controller coupled to each of the plurality of injectors, the controller being adapted to: generating a plurality of maps based on the set of predefined conditions, each of the plurality of maps being associated with a corresponding temperature of a heat rejection heat exchanger; identifying a first map from the plurality of maps that is associated with a first temperature of the heat rejection heat exchanger and an input signal indicative of a flow rate of a refrigerant fluid through a first ejector; identifying, from the plurality of maps, a second map associated with a second temperature of the heat rejection heat exchanger; predicting an opening percentage of the first injector from at least one of a plurality of opening percentages indicated in the first map and a plurality of opening percentages indicated in the second map; as well as The opening percentage of the first injector is adjusted based on the predicted opening percentage.

2. The system according to claim 1, wherein: Predicting the opening percentage includes: identifying a first opening percentage from the plurality of opening percentages indicated in the first map, and identifying a second opening percentage from the plurality of opening percentages indicated in the second map; performing linear interpolation to fit a line between the identified first opening percentage and the identified second opening percentage; identifying a slope of the line as a rate of change of the flow rate of the refrigerant fluid through the first ejector; and The opening percentage that the first injector will maintain is predicted based on an interpolation of the identified slope when the heat rejection heat exchanger is at an intermediate temperature between the first temperature and the second temperature.

3. The system according to claim 1, wherein: Each of the plurality of maps indicates a rate of change of the flow rate of the refrigerant fluid passing through each of the plurality of ejectors based on a change in the percentage of opening of each of the plurality of ejectors during a corresponding temperature of the heat rejection heat exchanger.

4. The system according to claim 1, wherein: Each of the plurality of maps includes a plurality of stages, and the opening percentage of at least the first injector from the plurality of injectors is greater than zero in each of the plurality of stages.

5. The system according to claim 4, wherein: The multiple stages include at least: A first stage, wherein the opening percentages of the plurality of injectors other than the first injector are equal to zero; a second stage, wherein the opening percentages of the plurality of injectors other than the first and second injectors are equal to zero; and The third stage, wherein the opening percentages of the plurality of injectors other than the first injector, the second injector, and the third injector are equal to zero.

6. The system according to claim 5, wherein: When transitioning between the plurality of stages of the first spectrum, the controller is further configured to: performing extrapolation to fit a line to the plurality of opening percentages within a predefined hysteresis band indicated in the first map; identifying a slope of the line as a rate of change of the flow rate of the refrigerant fluid through the first ejector; as well as The opening percentages that the plurality of injectors will maintain are predicted based on interpolation of the identified slopes.

7. The system according to claim 1, wherein: The set of predefined conditions includes: The opening percentages of the plurality of injectors are increased in a stage; When switching between the plurality of stages of each of the plurality of maps, the opening percentages of the plurality of ejectors are adjusted to maintain the flow rate of the refrigerant fluid constant; When switching between the plurality of stages of each of the plurality of maps, the opening percentages of the plurality of injectors are greater than zero; and A flow rate of the refrigerant fluid passing through the secondary low pressure input port of each of the plurality of ejectors is greater than zero.

8. The system according to claim 1, wherein: The plurality of injectors are controllable variable injectors connected in a parallel configuration.

9. The system according to claim 1, wherein: The ejector refrigeration circuit comprises: The high-pressure ejector circuit comprises, in the flow direction of the circulating refrigerant: said heat rejection heat exchanger having an inlet side and an outlet side; the plurality of ejectors, each of the plurality of ejectors having the primary high pressure input port, the secondary low pressure input port, and the output port, wherein the primary high pressure input port is in fluid communication with the outlet side of the heat rejection heat exchanger; a receiver having an inlet, a liquid outlet, and a gas outlet, the inlet being in fluid communication with the output port of each of the plurality of ejectors; at least one compressor having an inlet side and an outlet side, the inlet side of the at least one compressor being in fluid communication with the gas outlet of the receiver and the outlet side of the at least one compressor being in fluid communication with the inlet side of the heat rejection heat exchanger; and A refrigeration evaporator flow path, which includes, in the flow direction of the circulating refrigerant: a liquid pump having an inlet side and an outlet side, the inlet side being in fluid communication with the liquid outlet of the receiver; at least one refrigeration expansion device having an inlet side and an outlet side, the inlet side of the at least one refrigeration expansion device being in fluid communication with the outlet side of the liquid pump; and At least one refrigeration evaporator has an inlet side and an outlet side, the inlet side being in fluid communication with the outlet side of the at least one refrigeration expansion device and the outlet side being in fluid communication with the sub-low pressure input port of each of the plurality of ejectors.

10. The system according to claim 9, wherein: The liquid pump includes a bypass line having a switchable bypass valve for allowing refrigerant to selectively bypass the liquid pump by opening the switchable bypass valve.

11. A method for map interpolation-based control of a plurality of ejectors in an ejector refrigeration circuit, the method comprising: generating, via a controller, a plurality of maps based on a set of predefined conditions, each of the plurality of maps being associated with a corresponding temperature of a heat rejection heat exchanger; identifying, via the controller, from the plurality of maps, a first map associated with a first temperature of the heat rejection heat exchanger and an input signal indicative of a flow rate of a refrigerant fluid through a first ejector; as well as identifying, via the controller, from the plurality of maps, a second map associated with a second temperature of the heat rejection heat exchanger; predicting, via the controller, an opening percentage of the first injector from at least one of a plurality of opening percentages indicated in the first map and a plurality of opening percentages indicated in the second map; as well as The opening percentage of the first injector is adjusted via the controller based on the predicted opening percentage.

12. The method according to claim 11, wherein: Predicting the opening percentage includes: identifying a first opening percentage from the plurality of opening percentages indicated in the first map, and identifying a second opening percentage from the plurality of opening percentages indicated in the second map; performing linear interpolation to fit a line between the identified first opening percentage and the identified second opening percentage; identifying a slope of the line as a rate of change of the flow rate of the refrigerant fluid through the first ejector; and The opening percentage that the first injector will maintain is predicted based on an interpolation of the identified slope when the heat rejection heat exchanger is at an intermediate temperature between the first temperature and the second temperature.

13. The method according to claim 11, wherein: Each of the plurality of maps indicates a rate of change of the flow rate of the refrigerant fluid passing through each of the plurality of ejectors based on a change in the percentage of opening of each of the plurality of ejectors during a corresponding temperature of the heat rejection heat exchanger.

14. The method according to claim 13, wherein: Each of the plurality of maps includes a plurality of stages, and the opening percentage of at least the first injector from the plurality of injectors is greater than zero in each of the plurality of stages.

15. The method according to claim 13, wherein: The multiple stages include at least: A first stage, wherein the opening percentages of the plurality of injectors other than the first injector are equal to zero; a second stage, wherein the opening percentages of the plurality of injectors other than the first and second injectors are equal to zero; and The third stage, wherein the opening percentages of the plurality of injectors other than the first injector, the second injector, and the third injector are equal to zero.

16. The method according to claim 15, wherein: When transitioning between the plurality of stages of the first spectrum, the controller is further configured to: performing extrapolation to fit a line to the plurality of opening percentages within a predefined hysteresis band indicated in the first map; identifying a slope of the line as a rate of change of the flow rate of the refrigerant fluid through the first ejector; as well as The opening percentages that the plurality of injectors will maintain are predicted based on interpolation of the identified slopes.

17. The method according to claim 11, wherein: The set of predefined conditions includes: The opening percentages of the plurality of injectors are increased in a stage; When switching between the plurality of stages of each of the plurality of maps, the opening percentages of the plurality of ejectors are adjusted to maintain the flow rate of the refrigerant fluid constant; When switching between the plurality of stages of each of the plurality of maps, the opening percentages of the plurality of injectors are greater than zero; and A flow rate of the refrigerant fluid passing through the secondary low pressure input port of each of the plurality of ejectors is greater than zero.

18. The method according to claim 11, wherein: Each of the plurality of ejectors includes a primary high pressure input port, a secondary low pressure input port, and an output port.

19. The method according to claim 11, wherein: The ejector refrigeration circuit comprises: The high-pressure ejector circuit comprises, in the flow direction of the circulating refrigerant: said heat rejection heat exchanger having an inlet side and an outlet side; the plurality of ejectors, each of the plurality of ejectors having the primary high pressure input port, the secondary low pressure input port, and the output port, wherein the primary high pressure input port is in fluid communication with the outlet side of the heat rejection heat exchanger; a receiver having an inlet, a liquid outlet, and a gas outlet, the inlet being in fluid communication with the output port of each of the plurality of ejectors; at least one compressor having an inlet side and an outlet side, the inlet side of the at least one compressor being in fluid communication with the gas outlet of the receiver and the outlet side of the at least one compressor being in fluid communication with the inlet side of the heat rejection heat exchanger; and A refrigeration evaporator flow path, which includes, in the flow direction of the circulating refrigerant: a liquid pump having an inlet side and an outlet side, the inlet side being in fluid communication with the liquid outlet of the receiver; at least one refrigeration expansion device having an inlet side and an outlet side, the inlet side of the at least one refrigeration expansion device being in fluid communication with the outlet side of the liquid pump; and At least one refrigeration evaporator has an inlet side and an outlet side, the inlet side being in fluid communication with the outlet side of the at least one refrigeration expansion device and the outlet side being in fluid communication with the sub-low pressure input port of each of the plurality of ejectors.

20. The method according to claim 19, wherein: The liquid pump includes a bypass line including a switchable bypass valve allowing refrigerant to selectively bypass the liquid pump by opening the switchable bypass valve.

Images