Multi-compressor system with oil balance control

Abstract

A climate control system may include first and second compressors and an intake manifold. The first compressor includes a first housing, a first compression mechanism, and a first suction inlet through which a working fluid is sucked into the first compressor. The second compressor includes a second housing, a second compression mechanism, and a second suction inlet through which the working fluid is sucked into the second compressor. The suction manifold includes a first arm and a second arm. The first arm provides working fluid to the first suction inlet. The second arm provides working fluid to the second suction inlet. The second arm includes a first suction tube, a second suction tube, and a suction valve. The suction valve is movable between a first position allowing the working fluid to flow through the first suction tube and a second position allowing the working fluid to flow through the second suction tube.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit and priority of Indian Patent Application No. 202221047293 filed on August 19, 2022, and also claims the benefit of U.S. Non-provisional Application No. 18 / 201,511 filed on May 24, 2023. The entire disclosures of the above applications are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to climate control systems, and more particularly to a multiple compressor system with oil balancing control. Background Art

[0004] This section provides background information related to the present disclosure and is not necessarily prior art.

[0005] A climate control system, such as a heat pump system, a refrigeration system, or an air conditioning system, may include a fluid circuit having an outdoor heat exchanger, an indoor heat exchanger, an expansion device disposed between the indoor heat exchanger and the outdoor heat exchanger, and one or more compressors that circulate a working fluid (e.g., a refrigerant or carbon dioxide) between the indoor heat exchanger and the outdoor heat exchanger. During operation of a multi-compressor system, the oil level in one or more of the compressors may decrease, while the oil level in another one or more of the compressors may increase. The present disclosure provides apparatus and method steps for balancing the oil level between multiple compressors and / or reducing the oil loss in one or more of the compressors. Maintaining sufficient oil levels in the compressors will improve the efficiency and reliability of the compressors and will enable the climate control system to effectively and efficiently provide cooling and / or heating effects as needed. Summary of the invention

[0006] This section provides a general summary of the disclosure and is not a comprehensive disclosure of the full scope of the disclosure or features of the disclosure.

[0007] The present disclosure provides a climate control system, which may include a first compressor, a second compressor and an intake manifold. The first compressor may include a first housing and a first compression mechanism. The first housing may include a first intake inlet through which a working fluid is sucked into the first compressor for compression in the first compression mechanism. The second compressor may include a second housing and a second compression mechanism. The second housing may include a second intake inlet through which a working fluid is sucked into the second compressor for compression in the second compression mechanism. The intake manifold may include a first arm and a second arm. The first arm may be coupled to the first intake inlet and may be configured to provide a working fluid to the first intake inlet. The second arm may be coupled to the second intake inlet and may be configured to provide a working fluid to the second intake inlet. The second arm includes a first intake pipe, a second intake pipe and an intake valve. The intake valve is capable of moving between the following positions: (i) a first position in which fluid is prevented from flowing through the second intake pipe and the working fluid is allowed to flow through the first intake pipe to the second intake inlet, and (ii) a second position in which fluid is prevented from flowing through the first intake pipe and the working fluid is allowed to flow through the second intake pipe to the second intake inlet.

[0008] In some configurations, the climate control system of the above paragraph may include a control module that communicates with the suction valve and controls a position of the suction valve to control lubricant levels in the first housing and the second housing.

[0009] In some configurations of the climate control system of any of the above paragraphs, the control module controls the position of the suction valve based on which of the first compressor and the second compressor are operating and which compressors are off.

[0010] In some configurations of the climate control system of any of the above paragraphs, the control module controls the position of the suction valve based on capacity levels of the first compressor and the second compressor.

[0011] In some configurations of the climate control system of any of the above paragraphs, the control module controls the position of the intake valve based on data received from the high-side sensor and the low-side sensor.

[0012] In some configurations of the climate control system of any of the above paragraphs, the high side sensor is disposed upstream of the expansion device and downstream of the discharge outlet of the first compressor and the discharge outlet of the second compressor.

[0013] In some configurations of the climate control system of any of the above paragraphs, the low side sensor is disposed downstream of the expansion device and upstream of the first suction inlet and the second suction inlet.

[0014] In some configurations of the climate control system of any of the above paragraphs, fluid flow through the second suction conduit is more restricted than fluid flow through the first suction conduit.

[0015] In some configurations of the climate control system of any of the above paragraphs, the first suction conduit has a first diameter and the second suction conduit has a second diameter. The first diameter is greater than the second diameter.

[0016] In some configurations of the climate control system of any of the above paragraphs, the greater restriction to fluid flow through the second suction conduit is due to a bend in the second suction conduit.

[0017] In some configurations of the climate control system of any of the above paragraphs, the position of the intake valve is determined based on a predefined operating envelope.

[0018] In some configurations of the climate control system of any of the above paragraphs, the intake manifold includes an inlet configured to receive a suction pressure working fluid from the heat exchanger. A first portion of the working fluid received in the inlet of the intake manifold flows to a first arm of the intake manifold, and a second portion of the working fluid received in the inlet of the intake manifold flows to a second arm of the intake manifold.

[0019] In another form, the present disclosure provides a climate control system that may include a first compressor, a second compressor, a lubricant equalization pipeline, and an intake manifold. The first compressor may include a first housing and a first compression mechanism. The first housing may define a first suction chamber from which the first compression mechanism draws a working fluid. The first housing may include a first suction inlet through which the working fluid is drawn into the first suction chamber for compression in the first compression mechanism. The second compressor may include a second housing and a second compression mechanism. The second housing may define a second suction chamber from which the second compression mechanism draws a working fluid. The second housing may include a second suction inlet through which the working fluid is drawn into the second suction chamber for compression in the second compression mechanism. The lubricant equalization pipeline may extend between the first compressor and the second compressor and may be in fluid communication with the lubricant pool of the first compressor and the lubricant pool of the second compressor. The intake manifold may include a first arm and a second arm. The first arm may be coupled to the first suction inlet and may be configured to provide a working fluid to the first suction inlet. The second arm may be coupled to the second suction inlet and may be configured to provide a working fluid to the second suction inlet. The second arm may include a first suction pipe, a second suction pipe, and an intake valve. The suction valve is capable of moving between the following positions: (i) a first position, in which the fluid is blocked from flowing through the second suction pipe and the working fluid is allowed to flow through the first suction pipe to the second suction inlet, and (ii) a second position, in which the fluid is blocked from flowing through the first suction pipe and the working fluid is allowed to flow through the second suction pipe to the second suction inlet.

[0020] In some configurations, the climate control system of the above paragraph may include a control module that communicates with the suction valve and controls the position of the suction valve to control the lubricant level in the first housing and the second housing. The control module may be configured to equalize the pressure in the first suction chamber and the second suction chamber of the first compressor and the second compressor by controlling the position of the suction valve to maintain the lubricant level in the lubricant sump of the first compressor and the lubricant sump of the second compressor above the lubricant equalization line.

[0021] In some configurations of the climate control system of any of the above paragraphs, the position of the intake valve is determined based on a predefined operating envelope.

[0022] In some configurations of the climate control system of any of the foregoing paragraphs, the control module controls the position of the suction valve based on which of the first compressor and the second compressor are operating and which compressors are off.

[0023] In some configurations of the climate control system of any of the above paragraphs, the control module controls the position of the suction valve based on capacity levels of the first compressor and the second compressor.

[0024] In some configurations of the climate control system of any of the above paragraphs, the control module controls the position of the intake valve based on data received from the high-side sensor and the low-side sensor.

[0025] In some configurations of the climate control system in the above paragraph, the high-side sensor is disposed upstream of the expansion device and downstream of the discharge outlet of the first compressor and the discharge outlet of the second compressor, and the low-side sensor is disposed downstream of the expansion device and upstream of the first suction inlet and the second suction inlet.

[0026] In some configurations of the climate control system of any of the above paragraphs, fluid flow through the second suction conduit is more restricted than fluid flow through the first suction conduit.

[0027] In some configurations of the climate control system of any of the above paragraphs, the first suction conduit has a first diameter and the second suction conduit has a second diameter. The first diameter is greater than the second diameter.

[0028] In some configurations of the climate control system of any of the above paragraphs, the greater restriction to fluid flow through the second suction conduit is due to a bend in the second suction conduit.

[0029] In some configurations of the climate control system of any of the above paragraphs, the position of the intake valve is determined based on a predefined operating envelope.

[0030] In some configurations of the climate control system of any of the foregoing paragraphs, the suction manifold includes an inlet configured to receive suction-pressure working fluid from the heat exchanger.

[0031] In some configurations of the climate control system of the above paragraph, a first portion of the working fluid received in the inlet of the intake manifold flows to the first arm of the intake manifold, and a second portion of the working fluid received in the inlet of the intake manifold flows to the second arm of the intake manifold.

[0032] Further areas of applicability will become apparent from the description provided herein.The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0034] Figure 1 is a schematic diagram of a climate control system according to the principles of the present disclosure;

[0035] Figure 2 is a schematic diagram of a first compressor and a second compressor of a climate control system;

[0036] Figure 3 is a diagram depicting a control module of a climate control system in communication with a sensor and an intake valve of the climate control system;

[0037] Figure 4 is a perspective view of a first compressor and a second compressor of a climate control system;

[0038] Figure 5 is a top view of a first compressor and a second compressor of a climate control system;

[0039] Figure 6 is a flow chart showing steps performed by a control module to control a suction valve;

[0040] Figure 7 is an example operational envelope diagram according to the principles of the present disclosure;

[0041] Figure 8 is a perspective view of a first compressor and a second compressor or another climate control system according to the principles of the present disclosure;

[0042] Fig. 9 yes Figure 8 A top view of a first compressor and a second compressor; and

[0043] Fig.10 yes Figure 8 A side view of a first compressor and a second compressor.

[0044] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION

[0045] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0046] Example embodiments are provided so that the present disclosure will be thorough and will fully convey the scope to those skilled in the art. Many specific details such as examples of specific components, devices and methods are set forth to provide a thorough understanding of the embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, and that example embodiments may be implemented in many different forms, and none should be construed as limiting the scope of the present disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0047] The terms used herein are only used to describe the purpose of specific example embodiments, and are not intended to be restrictive. As used herein, unless the context clearly indicates otherwise, the singular forms "one", "a kind of" and "the" may also be intended to include plural forms. The terms "comprise", "including", "comprising" and "having" are inclusive, and therefore specify the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or their groups. The method steps, processes and operations described herein should not be interpreted as necessarily requiring them to be performed in the particular order discussed or illustrated, unless specifically indicated as the order of execution. It should also be understood that additional steps or alternative steps may be adopted.

[0048] When an element or layer is referred to as "on another element or layer", "engaged to", "connected to" or "coupled to" another element or layer, the element or layer may be directly on another element or layer, directly engaged to, directly connected to or directly coupled to another element or layer, or there may be an intermediate element or layer. On the contrary, when an element is referred to as "directly on another element or layer", "directly engaged to", "directly connected to" or "directly coupled to" another element or layer, there may be no intermediate element or layer. Other words used to describe the relationship between elements (for example, "between" and "directly between", "adjacent" and "directly adjacent", etc.) should be interpreted in a similar manner. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0049] Although the terms first, second and third etc. can be used to describe various elements, components, regions, layers and / or parts in this article, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless clearly indicated by the context, terms such as "first", "second" and other numerical terms do not imply sequence or order when used in this article. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0050] For ease of description, spatially relative terms such as "inside", "outside", "below", "below", "lower", "above", "upper", etc. may be used herein to describe the relationship of one element or feature to another element or feature as illustrated in the accompanying drawings. Spatially relative terms may be intended to cover different orientations of the device in use or operation other than the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, the elements described as being "below" or "below" other elements or features will then be oriented to be "above" the other elements or features. Therefore, the example term "below" can cover both the above and below orientations. The device can be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein can be interpreted accordingly.

[0051] Reference Figure 1 , a climate control system 10 is provided, which may include a first compressor 12, a second compressor 14, a first heat exchanger (e.g., a condenser or a gas cooler) 16, an expansion device (e.g., an expansion valve or a capillary tube) 18, and a second heat exchanger (e.g., an evaporator) 20. The climate control system 10 may be a refrigeration system, an air conditioning system, a heat pump system, etc., although Figure 1 The climate control system 10 shown in FIG. 1 includes two compressors, but in some configurations, the climate control system 10 may include more than two compressors.

[0052] Now refer to Figure 2 , each of the first compressor 12 and the second compressor 14 may include a housing 22, a motor 24, and a compression mechanism 26. The housing 22 defines a compressor housing in which the motor 24 and the compression mechanism 26 are disposed. The housing 22 may include a partition 28 that separates a suction chamber 30 from a discharge chamber 32. A discharge outlet 34 may be attached to the housing 22 and may receive a compressed working fluid from the discharge chamber 32. The partition 28 may include a discharge passage 38 therethrough that provides communication between the compression mechanism 26 and the discharge chamber 32. A suction inlet 36 may be attached to the housing 22 and may provide suction pressure working fluid to the suction chamber 30.

[0053] The suction manifold 39 may be fluidly coupled to the suction inlets 36 of both compressors 12, 14. The suction manifold may include an inlet 40, a first arm 41, and a second arm 42. The inlet 40 of the suction manifold 39 may receive the working fluid from the suction conduit 56. The first arm 41 may fluidly connect the inlet 40 with the suction inlet 36 of the first compressor 12. The second arm 42 of the suction manifold 39 may fluidly connect the inlet 40 with the suction inlet 36 of the second compressor 14. In this manner, the working fluid from the inlet 40 may flow to the first compressor 12 via the first arm 41 and to the second compressor 14 via the second arm 42.

[0054] The second arm 42 of the suction manifold 39 may include a suction valve 43, a first suction pipe 44, and a second suction pipe 45. The suction valve 43 may be, for example, a solenoid valve or any suitable type of valve (e.g., an electromechanical valve, a pneumatic valve, or a hydraulic valve). The suction valve 43 is fluidly coupled to the first suction pipe 44 and the second suction pipe 45 and controls the flow of fluid through the first suction pipe 44 and the second suction pipe 45. That is, the suction valve 43 is capable of moving between the following positions: (i) a first position in which the fluid is prevented from flowing through the second suction pipe 45 and the working fluid is allowed to flow from the inlet 40 of the suction manifold 39 and flow through the first suction pipe 44 to the suction inlet 36 of the second compressor 14, and (ii) a second position in which the fluid is prevented from flowing through the first suction pipe 44 and the working fluid is allowed to flow from the inlet 40 of the suction manifold 39 and flow through the second suction pipe 45 to the suction inlet 36 of the second compressor 14. In some configurations, the suction valve 43 is movable to a third position in which fluid is prevented from flowing through both the first suction conduit 44 and the second suction conduit 45 (ie, to prevent fluid from flowing into the second compressor 14 when only the second compressor 14 is shut down).

[0055] The first suction pipe 44 and the second suction pipe 45 can be configured such that the second suction pipe 45 restricts the flow into the suction inlet 36 of the second compressor 14 more than the first suction pipe 44 restricts the flow into the suction inlet 36 of the second compressor 14. That is, the second suction pipe 45 produces a greater pressure drop for the fluid flowing therethrough than the pressure drop for the fluid flowing through the first suction pipe 44. For example, in some configurations, the diameter of the first suction pipe 44 can be greater than the diameter of the second suction pipe 45 (e.g., in FIG. 1 ). Figure 2 , Figure 4 and Figure 5 In some configurations, the second suction tube 45 may have more bends and / or one or more sharper (tighter) bends than the first suction tube 44 to produce a greater pressure drop (as will be described below). Figures 8 to 10 described in more detail).

[0056] As in Figure 2 As shown in FIG. 1 , the lower end of the housing 22 of each of the compressors 12, 14 may define a lubricant sump 46 containing a volume of liquid lubricant (eg, oil). A lubricant equalization conduit 48 ( Figure 2 , Figure 4 and Figure 5 ) may extend between the first compressor 12 and the second compressor 14 and may be fluidly coupled to an oil fitting attached to the housing 22 such that the lubricant equalization line 48 is in fluid communication with the lubricant sumps 46 of both compressors 12, 14 (i.e., such that lubricant may flow between the lubricant sumps 46 of the first compressor 12 and the lubricant sumps 46 of the second compressor 14 through the lubricant equalization line 48). The gas equalization line 49 ( Figure 2 , Figure 4 and Figure 5 ) may extend between the first compressor 12 and the second compressor 14 and may be fluidly coupled with a fitting attached to the casing 22 such that the gas equalization conduit 49 is in fluid communication with the suction chambers 30 of both compressors 12 , 14 .

[0057] The motor 24 ( Figure 2 ) may include a stator and a rotor. The stator may be press-fitted into the housing 22. The rotor may be fixed to a drive shaft 50, and the drive shaft 50 may drive the compression mechanism 26. The compression mechanism 26 may be a scroll compression mechanism including a first scroll member and a second scroll member (e.g., a movable scroll member and a fixed scroll member or a pair of co-rotating scroll members), the first scroll member and the second scroll member including a spiral scroll that cooperates to define a compression chamber therebetween. It should be understood that the compression mechanism 26 may be, for example, any other type of compression mechanism, such as a rotary compression mechanism (e.g., having an eccentric rotor that rotates within a cylinder, and having reciprocating blades that extend into the cylinder) or a reciprocating compression mechanism (e.g., having a piston that reciprocates within a cylinder).

[0058] The second compressor 14 is capable of operating at a lower capacity than the first compressor 12. In some examples, one or both of the compressors 12, 14 may be a variable capacity compressor. That is, one or both of the compressors 12, 14 may be or include one or more of the following: a multi-stage compression mechanism, a multi-speed or variable speed motor, a steam injection system (e.g., an economizer circuit), a pulse width modulated scroll compressor configured for scroll separation (e.g., a digital scroll compressor), and a compressor having a capacity regulating valve configured to leak an intermediate pressure working fluid. It should be understood that one or both of the compressors 12, 14 may include any other additional or alternative structure for changing its capacity and / or the operating capacity of the climate control system 10. Example variable capacity compressors are disclosed in Assignee's commonly owned U.S. Patent Nos. 8,616,014, 6,679,072, 8,585,382, 6,213,731, 8,485,789, and 8,459,053, the disclosures of which are incorporated herein by reference. Control module 52 ( Figure 3 ) can control the operation of the compressors 12, 14, including starting the compressors 12, 14, shutting down the compressors 12, 14, and adjusting or modulating the capacity of the compressors 12, 14.

[0059] Now refer to Figure 1 and Figure 2 During operation of the climate control system 10, the compression mechanism 26 of one or both of the compressors 12, 14 may draw a suction-pressure working fluid (e.g., refrigerant, carbon dioxide, etc.) from its respective suction chamber 30, may compress the working fluid to a higher pressure, and may discharge the compressed working fluid into its respective discharge chamber 32. The compressed working fluid in the discharge chamber 32 of the compressor 12, 14 may flow through the discharge outlet 34 and into the discharge conduit 54.

[0060] The working fluid in the discharge conduit 54 can flow through the first heat exchanger 16, where heat is absorbed from the working fluid. The working fluid can flow from the first heat exchanger 16 through the expansion device 18. The pressure and temperature of the working fluid drop as the working fluid flows through the expansion device 18. The working fluid can flow from the expansion device 18 through the second heat exchanger 20, where the working fluid absorbs heat from the space to be cooled. The working fluid flows from the second heat exchanger 20 to the suction manifold 39 via the suction conduit 56. The working fluid can flow from the suction manifold 39 to one or both of the compressors 12, 14 through the suction inlet 36. The suction valve 43 controls the flow of the working fluid to the first compressor 12 and the second compressor 14, respectively.

[0061] Control module 52( Figure 3 ) may be in communication with the suction valve 43 and may control the operation of the suction valve 43 to equalize the fluid pressures within the suction chamber 30 of the first compressor 12 and the suction chamber 30 of the second compressor 14 (or to reduce the difference between the fluid pressures of the suction chamber 30 of the first compressor 12 and the suction chamber 30 of the second compressor 14). Equalizing the fluid pressures within the suction chambers 30 of the first compressor 12 and the second compressor 14 maintains the balance of lubricant in the reservoirs 46 of the first compressor 12 and the second compressor 14 (i.e., equalizes the lubricant levels). This prevents the lubricant level within either compressor 12, 14 from becoming too low so that both compressors 12, 14 remain adequately lubricated. For example, if Figure 2 As shown in FIG. 4 , the control module 52 may control the suction valve 43 to maintain the lubricant level 47 in the lubricant sump 46 of both the first compressor 12 and the second compressor 14 vertically above the lubricant equalization line 48 .

[0062] The suction valve 43 can be any suitable type of valve that can move between a first position (allowing fluid to flow through the first suction pipe 44 and preventing fluid from flowing through the second suction pipe 45) and a second position (allowing fluid to flow through the second suction pipe 45 and preventing fluid from flowing through the first suction pipe 44). In some configurations, the suction valve 43 can move to one or more intermediate positions between the first position and the second position. The suction valve 43 can be a ball valve, a butterfly valve, or any other type of valve driven by a solenoid, a stepper motor, or any other suitable actuator.

[0063] In some configurations, the control module 52 can control the intake valve 43 based on operating parameters of the climate control system 10. For example, the control module 52 can control the intake valve 43 based on information received from the first sensor 60 and / or the second sensor 62. In some configurations, the first sensor 60 can be a high-side sensor (e.g., a temperature sensor or a pressure sensor disposed along the discharge conduit 54), and the second sensor 62 can be a low-side sensor (e.g., a temperature sensor or a pressure sensor disposed along the intake conduit 56).

[0064] The control module 52 may execute Figure 6 , to intermittently or continuously adjust the position of the suction valve 43 based on the operating conditions of the compressors 12 , 14 and / or the climate control system 10 to equalize the fluid pressures within the suction chambers 30 of the first compressor 12 and the suction chambers 30 of the second compressor 14 .

[0065] like Figure 6As shown in FIG. 1 , at step 110 , the control module 52 may receive a signal from the high-side sensor 60 ( Figure 1 and Figure 3 ) and the high side temperature value (or high side pressure value) from the low side sensor 62 ( Figure 1 and Figure 3 ). For example, the high-side sensor 60 may be a temperature sensor (or pressure sensor) disposed along the discharge pipe 54 or disposed on the first heat exchanger 16. Therefore, the high-side temperature value may be a discharge temperature or a condensing temperature. For example, the low-side sensor 62 may be a temperature sensor (or pressure sensor) disposed along the suction pipe 56 or disposed on the second heat exchanger 20. Therefore, the low-side temperature value may be a suction temperature or an evaporation temperature.

[0066] At step 120, the control module 52 may identify which one or more of the compressors 12, 14 are currently operating (i.e., which compressors 12, 14 are not in an off state). This may be accomplished in a variety of ways, including, for example, reading current values ​​from sensors measuring the current draw of the motors 24 of the compressors 12, 14, reading pressure values ​​and / or temperature values ​​from sensors located at or near the discharge outlets 34 and / or suction inlets 36 of the compressors 12, 14, and / or referencing states of other algorithms executed by the control module 52 for controlling, diagnosing, and / or protecting the compressors 12, 14. In some configurations, the control module 52 may employ additional or alternative means or steps to identify which one or more of the compressors 12, 14 are currently operating.

[0067] At step 130, the control module 52 may identify the modulation state or capacity level of one or more compressors 12, 14 identified as currently operating at step 120. That is, at step 130, for each compressor 12, 14 currently operating, the control module 52 may identify whether the compressor 12, 14 is operating at zero capacity, full capacity, or an intermediate capacity level between zero capacity and full capacity. The control module 52 may also identify the value of the intermediate capacity level at which one or more of the compressors 12, 14 may currently be operating. Identifying the capacity level of the operating compressor 12, 14 may be accomplished in a variety of ways, including, for example, reading current values ​​from sensors measuring the current consumption of the motor 24 of the compressor 12, 14, reading pressure values ​​and / or temperature values ​​from sensors at or near the discharge outlet 34 and / or the suction inlet 36 of the compressor 12, 14, and / or referring to the state of other algorithms executed by the control module 52 for controlling, diagnosing, and / or protecting the compressor 12, 14. In some configurations, the control module 52 may employ additional or alternative means or steps to identify the capacity level of the operating compressors 12 , 14 .

[0068] One or more predefined operating profiles may be stored in a memory of the control module 52 or in a memory of a module in communication with the control module 52 . Figure 7 An example of an operational envelope diagram 135 that may be included in a plurality of predefined operational envelope diagrams is depicted. The plurality of operational envelope diagrams stored in the memory may include additional or different operational envelope diagrams corresponding to different combinations of information that may be identified by the control module 52 at steps 120 and 130.

[0069] At step 140, the control module 52 may identify one of the operating envelopes that corresponds to the following conditions: (a) the number of compressors 12, 14 identified as being in operation (identified in step 120), and (b) the modulation state (capacity level) of the compressors 12, 14 identified as being in operation. For example, if the control module 52 determines at steps 120 and 130 that both compressors 12, 14 are currently operating and both are operating at an intermediate capacity level, the control module 52 may identify one of the operating envelopes that corresponds to these conditions (e.g., at step 140) at the intermediate capacity level. Figure 7 As another example, if the control module 52 determines at steps 120 and 130 that both compressors 12, 14 are currently operating and that the first compressor 12 is operating at an intermediate capacity level and the second compressor 14 is operating at a full capacity level, the control module 52 may identify at step 140 one of the operating envelopes that corresponds to these conditions (e.g., Figure 7 Stored in the memory may be various operating envelope diagrams corresponding to different combinations of conditions identified at steps 120 , 130 .

[0070] Once the operating envelope corresponding to the current conditions (i.e., the conditions identified at steps 120, 130) has been identified (at step 140), the control module 52 may read the valve position on the identified operating envelope at step 150 based on the low-side temperature (e.g., suction or evaporation temperature) value and the high-side temperature (e.g., discharge or condensing temperature) value received at step 110. The operating envelopes each include a plurality of regions, and each of the regions corresponds to a different valve position.

[0071] For example, Figure 7 The operation envelope diagram 135 shown in includes: a first area marked as "Zone A", which corresponds to the first position of the suction valve 43 (in the first position, fluid is allowed to flow through the first suction pipe 44 and fluid is prevented from flowing through the second suction pipe 45); and a second area marked as "Zone B", which corresponds to the second position of the suction valve 43 (in the second position, fluid is allowed to flow through the second suction pipe 45 and fluid is prevented from flowing through the first suction pipe 44). Therefore, if the temperature value received at step 110 falls within the first area (Zone A), the control module 52 will determine at step 150 that the suction valve 43 should be moved to (or maintained at) the first position. If the temperature value received at step 110 falls within the second area (Zone B), the control module 52 will determine at step 150 that the suction valve 43 should be moved to (or maintained at) the second position. The valve position can be determined in the same manner from other operation envelope diagrams stored in the memory.

[0072] At step 160, the control module 52 may move the suction valve 43 to the valve position read at step 150. Moving the suction valve 43 to the position read at step 150 will equalize the fluid pressure within the suction chamber 30 of the first compressor 12 and the suction chamber 30 of the second compressor 14, so that the lubricant level in the first compressor 12 and the second compressor 14 can be maintained at approximately equal levels or at least at acceptable levels. The operating envelope and the valve position values ​​for each of the zones can be determined and plotted based on testing for a given climate control system. That is, during testing of a given climate control system, the valve position values ​​can be set so that the fluid pressure within the suction chamber 30 of the first compressor 12 and the suction chamber 30 of the second compressor 14 remains approximately equal.

[0073] After executing step 160, the control module 52 may loop back and continuously or intermittently execute steps 110 to 160. It should be understood that step 110 does not have to be executed before step 120, step 130, and step 140. Step 110 may be executed simultaneously with any of step 120, step 130, and step 140, or after any of step 120, step 130, and step 140.

[0074] In some configurations, if the first compressor 12 is currently operating and the second compressor 14 is currently off, the control module 52 may move the suction valve 43 to the third position, thereby preventing fluid flow through both the first suction conduit 44 and the second suction conduit 45 .

[0075] In some configurations, the control module 52 may determine the lubricant level in the sump 46 of the compressors 12, 14 after step 160 (e.g., based on data received from the oil level sensor), and if the lubricant levels in the compressors 12, 14 are unequal or if the lubricant level in one of the compressors 12, 14 falls below a predetermined acceptable level, the control module 52 may apply a correction factor to adjust the valve position value of the operating envelope to achieve an acceptable lubricant level.

[0076] In some configurations, the control module 52 may trigger a fault alarm and / or a compressor protection algorithm if adequate lubricant levels are not maintained in the compressors 12 , 14 .

[0077] Although the climate control system 10 is described above as having two compressors 12 , 14 , in some configurations, the climate control system 10 may have three or more compressors and multiple intake valves.

[0078] Reference Figures 8 to 10 Another intake manifold 239 is provided that may be incorporated into the climate control system 10 in place of the intake manifold 39 described above. The structure and function of the intake manifold 239 may be similar or identical to the structure and function of the intake manifold 39 described above, except for the differences described below.

[0079] The suction manifold 239 may be fluidly coupled to the suction inlets 36 of both compressors 12, 14. The suction manifold 239 may include an inlet 240, a first arm 241, and a second arm 242. The inlet 240 of the suction manifold 239 may receive the suction air from the suction duct 56 ( Figure 1). The first arm 241 can fluidly connect the inlet 240 to the suction inlet 36 of the first compressor 12. The second arm 242 of the suction manifold 239 can fluidly connect the inlet 240 to the suction inlet 36 of the second compressor 14. In this way, the working fluid from the inlet 240 can flow to the first compressor 12 via the first arm 241 and flow to the second compressor 14 via the second arm 242.

[0080] The second arm 242 of the suction manifold 239 may include a suction valve 243, a first suction pipe 244, and a second suction pipe 245. The suction valve 243 may be, for example, a solenoid valve or any suitable type of valve (e.g., an electromechanical valve, a pneumatic valve, or a hydraulic valve). The suction valve 243 is fluidly coupled to the first suction pipe 244 and the second suction pipe 245 and controls the flow of fluid through the first suction pipe 44 and the second suction pipe 45. That is, the suction valve 243 is capable of moving between the following positions: (i) a first position in which the fluid is prevented from flowing through the second suction pipe 245 and the working fluid is allowed to flow from the inlet 240 of the suction manifold 239 and flow through the first suction pipe 244 to the suction inlet 36 of the second compressor 14, and (ii) a second position in which the fluid is prevented from flowing through the first suction pipe 244 and the working fluid is allowed to flow from the inlet 240 of the suction manifold 239 and flow through the second suction pipe 45 to the suction inlet 36 of the second compressor 14. In some configurations, the suction valve 243 is movable to a third position in which fluid is prevented from flowing through both the first suction conduit 244 and the second suction conduit 245 (ie, to prevent fluid from flowing into the second compressor 14 when only the second compressor 14 is shut down).

[0081] The first suction pipe 244 and the second suction pipe 245 can be configured such that the second suction pipe 245 restricts the flow entering the suction inlet 36 of the second compressor 14 more than the first suction pipe 244 restricts the flow entering the suction inlet 36 of the second compressor 14. That is, the second suction pipe 245 produces a greater pressure drop for the fluid flowing therethrough than the pressure drop for the fluid flowing through the first suction pipe 244. For example, in some configurations, the second suction pipe 45 can have more bends and / or one or more sharper (tighter) bends than the first suction pipe 44 to produce a greater pressure drop (e.g., at Figures 8 to 10 ). In some configurations, the first suction tube 244 may also have a larger diameter than the diameter of the second suction tube 245. In other configurations, the diameter of the first suction tube 244 and the diameter of the second suction tube 245 may be approximately equal to each other.

[0082] The control module 52 is in communication with the suction valve 243 and controls the operation of the suction valve 243 in the same or similar manner as described above with respect to the suction valve 43. That is, the control module 52 may perform the following operations: Figure 6 Steps 110, 120, 130, 140, 150, 160 shown and described above.

[0083] In this application including the following definitions, the term "module" or the term "control module" may be replaced with the term "circuit". The term "module" may refer to, be part of, or include: an application specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor circuit (shared, dedicated, or group) that executes code; a memory circuit (shared, dedicated, or group) that stores code executed by the processor circuit; other suitable hardware components that provide the functionality; or a combination of some or all of the above, such as in a system on a chip.

[0084] The module may include one or more interface circuits. In some examples, the interface circuit may include a wired or wireless interface connected to a local area network (LAN), the Internet, a wide area network (WAN), or a combination thereof. The functions of any given module of the present disclosure may be distributed in multiple modules connected via the interface circuit. For example, multiple modules may allow load balancing. In another example, a server (also known as a remote or cloud) module may implement some functions on behalf of a client module.

[0085] The term code as used above may include software, firmware and / or microcode, and may refer to a program, a routine, a function, a class, a data structure and / or an object. The term shared processor circuit covers a single processor circuit that executes some or all of the code from multiple modules. The term group processor circuit covers a processor circuit that executes some or all of the code from one or more modules in combination with an additional processor circuit. Reference to multiple processor circuits covers multiple processor circuits on discrete dies, multiple processor circuits on a single die, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the above. The term shared memory circuit covers a single memory circuit that stores some or all of the code from multiple modules. The term group memory circuit covers a memory circuit that stores some or all of the code from one or more modules in combination with an additional memory.

[0086] The term memory circuit is a subset of the term computer-readable medium. As used herein, the term computer-readable medium does not encompass transient electrical or electromagnetic signals propagated through a medium (such as on a carrier wave); thus the term computer-readable medium may be considered to be tangible and non-transitory. Non-limiting examples of non-transitory, tangible computer-readable media are non-volatile memory circuits (such as flash memory circuits, erasable programmable read-only memory circuits, or mask read-only memory circuits), volatile memory circuits (such as static random access memory circuits or dynamic random access memory circuits), magnetic storage media (such as analog or digital tapes or hard drives), and optical storage media (such as CDs, DVDs, or Blu-ray discs).

[0087] In the present application, a device element described as having specific attributes or performing specific operations is specifically configured to have those specific attributes and perform those specific operations. Specifically, the description of an element to perform an action means that the element is configured to perform the action. The configuration of an element may include programming the element, such as by encoding instructions on a non-transitory, tangible computer-readable medium associated with the element.

[0088] The apparatus and methods described in this application may be implemented partially or completely by a special-purpose computer, which is created by configuring a general-purpose computer to perform one or more specific functions implemented in a computer program. The above drawings and descriptions serve as software specifications, which can be converted into computer programs by routine work of a skilled technician or programmer.

[0089] The computer program includes processor executable instructions stored on at least one non-transitory, tangible computer-readable medium. The computer program may also include or rely on stored data. The computer program may include a basic input / output system (BIOS) that interacts with the hardware of the special-purpose computer, device drivers that interact with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0090] A computer program may include: i) descriptive text to be parsed, such as HTML (Hypertext Markup Language), XML (Extensible Markup Language), or JSON (JavaScript Object Notation), (ii) assembly code, (iii) object code generated by a compiler from source code, (iv) source code executed by an interpreter, (v) source code compiled and executed by a just-in-time compiler, etc. By way of example only, the source code may be written using syntax from a language including: C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Fortran, Perl, Pascal, Curl, OCaml, HTML5 (Hypertext Markup Language Fifth Edition), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Visual Lua, MATLAB, SIMULINK, and

[0091] Unless an element is explicitly recited using the phrase "means for" or in the case of a method claim using the phrase "operation of" or "step of," no element recited in a claim is intended to be a means-plus-function element within the meaning of 35 U.S.C. §112(f).

[0092] The foregoing description of the embodiments has been provided for the purpose of illustration and description. The foregoing description is not intended to be exhaustive or to limit the present disclosure. The individual elements or features of a particular embodiment are generally not limited to the particular embodiment, but even if not specifically shown or described, the individual elements or features of a particular embodiment are interchangeable where applicable and can be used in a selected embodiment. The individual elements or features of a particular embodiment can also be changed in many ways. Such variations are not considered to be out of the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure.

Claims

1. A climate control system comprising: a first compressor, the first compressor comprising a first housing and a first compression mechanism, the first housing comprising a first suction inlet through which a working fluid is drawn into the first compressor for compression in the first compression mechanism; a second compressor including a second housing and a second compression mechanism, the second housing including a second suction inlet through which a working fluid is drawn into the second compressor for compression in the second compression mechanism; as well as a suction manifold having a first arm and a second arm, wherein the first arm is coupled to the first suction inlet and is configured to provide a working fluid to the first suction inlet, wherein the second arm is coupled to the second suction inlet and is configured to provide a working fluid to the second suction inlet, wherein the second arm comprises a first suction pipe, a second suction pipe and a suction valve, and Wherein, the suction valve is capable of moving between the following positions: (i) a first position, in which the fluid is prevented from flowing through the second suction pipe and the working fluid is allowed to flow through the first suction pipe to reach the second suction inlet, and (ii) a second position, in which the fluid is prevented from flowing through the first suction pipe and the working fluid is allowed to flow through the second suction pipe to reach the second suction inlet. 2 . The climate control system of claim 1 , further comprising a control module in communication with the suction valve and controlling a position of the suction valve to control a lubricant level in the first housing and the second housing.

3. The climate control system of claim 2, wherein: The control module controls a position of the suction valve based on which of the first and second compressors are operating and which compressors are off.

4. The climate control system of claim 3, wherein: The control module controls a position of the suction valve based on capacity levels of the first compressor and the second compressor.

5. The climate control system of claim 4, wherein: The control module controls a position of the suction valve based on data received from a high-side sensor and a low-side sensor.

6. The climate control system of claim 5, wherein: The high-side sensor is disposed upstream of an expansion device and downstream of the discharge outlet of the first compressor and the discharge outlet of the second compressor, and wherein the low-side sensor is disposed downstream of the expansion device and upstream of the first suction inlet and the second suction inlet.

7. The climate control system of claim 1, wherein: Fluid flow through the second suction conduit is more restricted than fluid flow through the first suction conduit.

8. The climate control system of claim 7, wherein: The first suction tube has a first diameter and the second suction tube has a second diameter, and wherein the first diameter is greater than the second diameter.

9. The climate control system of claim 7, wherein: The greater restriction to fluid flow through the second suction conduit is caused by the bend in the second suction conduit.

10. The climate control system of claim 1, wherein: The position of the suction valve is determined based on a predefined operating profile.

11. The climate control system of claim 1, wherein: The suction manifold includes an inlet configured to receive a suction-pressure working fluid from a heat exchanger, wherein a first portion of the working fluid received in the inlet of the suction manifold flows to the first arm of the suction manifold, and wherein a second portion of the working fluid received in the inlet of the suction manifold flows to the second arm of the suction manifold.

12. A climate control system comprising: a first compressor, the first compressor comprising a first housing and a first compression mechanism, the first housing defining a first suction chamber, the first compression mechanism drawing a working fluid from the first suction chamber, the first housing comprising a first suction inlet, the working fluid being drawn into the first suction chamber through the first suction inlet for compression in the first compression mechanism; a second compressor, the second compressor comprising a second housing and a second compression mechanism, the second housing defining a second suction chamber, the second compression mechanism drawing working fluid from the second suction chamber, the second housing comprising a second suction inlet, the working fluid being drawn into the second suction chamber through the second suction inlet for compression in the second compression mechanism; a lubricant equalization conduit extending between the first compressor and the second compressor and in fluid communication with a lubricant sump of the first compressor and a lubricant sump of the second compressor; as well as a suction manifold having a first arm and a second arm, wherein the first arm is coupled to the first suction inlet and is configured to provide a working fluid to the first suction inlet, wherein the second arm is coupled to the second suction inlet and is configured to provide a working fluid to the second suction inlet, wherein the second arm comprises a first suction pipe, a second suction pipe and a suction valve, and Wherein, the suction valve is capable of moving between the following positions: (i) a first position, in which the fluid is prevented from flowing through the second suction pipe and the working fluid is allowed to flow through the first suction pipe to reach the second suction inlet, and (ii) a second position, in which the fluid is prevented from flowing through the first suction pipe and the working fluid is allowed to flow through the second suction pipe to reach the second suction inlet.

13. The climate control system of claim 12, further comprising a control module in communication with the suction valve and controlling a position of the suction valve to control a lubricant level in the first housing and the second housing, wherein The control module is configured to equalize pressures within a first suction chamber of the first compressor and a second suction chamber of the second compressor by controlling a position of the suction valve to maintain lubricant levels in the lubricant sump of the first compressor and the lubricant sump of the second compressor above the lubricant equalization line.

14. The climate control system of claim 13, wherein: The position of the suction valve is determined based on a predefined operating profile.

15. The climate control system of claim 14, wherein: The control module controls a position of the suction valve based on which of the first compressor and the second compressor are operating and which compressors are off, wherein the control module controls the position of the suction valve based on the capacity levels of the first compressor and the second compressor, wherein the control module controls the position of the suction valve based on data received from the high-side sensor and the low-side sensor, wherein the high-side sensor is disposed upstream of an expansion device and downstream of a discharge outlet of the first compressor and a discharge outlet of the second compressor, and wherein the low-side sensor is disposed downstream of the expansion device and upstream of the first suction inlet and the second suction inlet.

16. The climate control system of claim 12, wherein: Fluid flow through the second suction conduit is more restricted than fluid flow through the first suction conduit.

17. The climate control system of claim 16, wherein: The first suction tube has a first diameter and the second suction tube has a second diameter, and wherein the first diameter is greater than the second diameter.

18. The climate control system of claim 16, wherein: The greater restriction to fluid flow through the second suction conduit is caused by the bend in the second suction conduit.

19. The climate control system of claim 12, wherein: The position of the suction valve is determined based on a predefined operating profile.

20. The climate control system of claim 12, wherein: The suction manifold includes an inlet configured to receive a suction-pressure working fluid from a heat exchanger, wherein a first portion of the working fluid received in the inlet of the suction manifold flows to the first arm of the suction manifold, and wherein a second portion of the working fluid received in the inlet of the suction manifold flows to the second arm of the suction manifold.

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