Water chilling unit

Abstract

The utility model discloses a water chilling unit which comprises a compressor, a condenser and an evaporator which are connected through a pipeline to form a refrigeration cycle system. The water chilling unit further comprises a flow control valve, a throttling element and a flow-adjustable electric valve. The flow of the flow control valve changes nonlinearly along with the opening degree, and the flow control valve is arranged on a pipeline between the condenser and the evaporator to form a main liquid path; the throttling element is arranged on a main liquid path between the condenser and the evaporator, and forms a throttling device together with the flow regulator; the caliber of the flow-adjustable electric valve is smaller than that of the flow control valve, so that a bypass adjusting branch located between the condenser and the evaporator is formed, and the bypass adjusting branch is used for compensating flow adjustment of the flow control valve by adjusting the opening degree of the flow-adjustable electric valve. According to the utility model, the bypass adjusting branch is arranged for the flow control valve of which the flow changes nonlinearly along with the opening degree, so that the accuracy and the consistency of flow adjustment and the stability of a system are improved.

Description

Technical Field

[0001] This utility model relates to the field of air conditioning technology, specifically to a chiller unit. Background Technology

[0002] Currently, large chiller units in the industry generally use an electrically adjustable ball valve in conjunction with a fixed orifice plate. Especially when the adjustable ball valve is a V-type ball valve, its adjustment is relatively precise and accurate at small openings, while the flow rate change corresponding to the valve adjustment increases sharply at large openings.

[0003] In the industry, PID control is generally used in conjunction with electric ball valves for liquid level regulation. However, PID control parameters cannot be adjusted in real time to change the regulation speed and amplitude at both small and large valve openings. This means that PID control cannot simultaneously ensure the accuracy and efficiency of valve regulation at both large and small openings. Setting the valve regulation amplitude too large can easily lead to over-adjustment or under-adjustment, causing large fluctuations in the liquid level within the heat exchanger when operating conditions change, which cannot be quickly stabilized. This can result in liquid carryover during suction or fluctuations in evaporation and condensation pressures, affecting the stability of unit operation. Setting the valve regulation amplitude too small minimizes liquid level fluctuations, but this affects the regulation speed at small valve openings and cannot fundamentally solve the problem of inconsistent regulation speeds.

[0004] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this application, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention

[0005] To address the problem of poor accuracy and consistency in regulating refrigerant flow in large chiller units using electrically adjustable ball valves in conjunction with fixed orifice plates, as mentioned in the background art, this utility model proposes a chiller unit with a bypass regulating branch for the electrically adjustable ball valve, thereby improving the accuracy and consistency of flow regulation and thus enhancing system stability.

[0006] To achieve the above-mentioned objectives, the present invention employs the following technical solution:

[0007] A chiller unit includes a compressor, a condenser, and an evaporator, which are connected by pipelines to form a refrigeration cycle system; it also includes a flow control valve, a throttling device, and an adjustable flow electric valve;

[0008] The flow control valve has a non-linear flow rate that varies with the opening degree and is installed on the pipeline between the condenser and the evaporator to form the main liquid path;

[0009] The throttling element is installed on the main liquid line and together with the flow control valve, forms a throttling device.

[0010] The diameter of the adjustable flow electric valve is smaller than that of the flow control valve, forming a bypass regulating branch located between the condenser and the evaporator, which is used to compensate for the flow regulation of the flow control valve by adjusting the opening of the adjustable flow electric valve.

[0011] The chiller unit of this invention features an adjustable flow bypass regulating branch in the main liquid circuit, which is linked to the flow control valve of the main liquid circuit. The regulating accuracy of the bypass regulating branch is higher than that of the flow control valve. This allows for coarse adjustment via the flow control valve and fine adjustment via the adjustable flow electric valve during flow regulation. This compensates for under-adjustment or over-adjustment caused by the nonlinear change in flow rate with the opening degree during flow control, overcoming inaccurate flow control and improving the accuracy and consistency of flow regulation. It also accelerates the stabilization of the heat exchanger liquid level and improves the stability and reliability of the system.

[0012] In some specific embodiments, an economizer is also included, which is located on the main liquid line and includes an air supply port; the air supply port is connected to the compressor and is used to supply air to the compressor;

[0013] The flow control valve includes a first flow control valve and a second flow control valve; the throttling element includes a first throttling element and a second throttling element; the first flow control valve and the first throttling element are connected in series between the condenser and the economizer; the second flow control valve and the second throttling element are connected in series between the economizer and the evaporator;

[0014] One end of the first throttling element and one end of the second flow control valve are respectively connected to the inlet and outlet of the economizer; the adjustable flow electric valve is connected in parallel with the first flow control valve.

[0015] In this embodiment, the chiller unit connects an adjustable flow electric valve with a higher adjustment accuracy than the first flow control valve in parallel. This allows the flow rate of the first flow control valve to be compensated or corrected by adjusting the opening of the adjustable flow electric valve. This overcomes the problem of under-adjustment or over-adjustment caused by the nonlinear change of flow rate with opening during the flow control process, thereby improving the accuracy and consistency of flow regulation. It also accelerates the stabilization of the heat exchanger liquid level and improves the stability and reliability of the system.

[0016] In some specific embodiments, an economizer is also included, which is located on the main liquid line and includes a gas supply port; the gas supply port is connected to the compressor to supply gas to the compressor;

[0017] The flow control valve includes a first flow control valve and a second flow control valve; the throttling element includes a first throttling element and a second throttling element; the first flow control valve and the first throttling element are connected in series between the condenser and the economizer; the second flow control valve and the second throttling element are connected in series between the economizer and the evaporator;

[0018] One end of the first throttling device and one end of the second flow control valve are respectively connected to the inlet and outlet of the economizer; the common end of the outlet and the second flow control valve, and the common end of the second flow control valve and the second throttling device are respectively connected to the two ends of the adjustable flow electric valve through pipelines.

[0019] In this embodiment, the chiller unit overcomes the problem of nonlinear flow rate variation with opening degree by adjusting the opening degree of the adjustable flow electric valve and the flow rate adjustment of the flow compensation second flow control valve, thereby improving the accuracy of system flow control and the stability and accuracy of evaporator liquid level, and improving system cooling efficiency.

[0020] In some specific embodiments, an economizer is also included, which is located on the main liquid line and includes a gas supply port; the gas supply port is connected to the compressor to supply gas to the compressor;

[0021] The throttling device includes a first throttling device and a second throttling device; the flow control valve, the first throttling device, the economizer, and the second throttling device are connected in series between the condenser and the evaporator;

[0022] The common end of the condenser and the flow control valve, and the common end of the second throttling element and the evaporator are respectively connected to the two ends of the adjustable flow electric valve through pipelines.

[0023] The chiller unit in this embodiment not only compensates for the flow regulation of the flow control valve by using an adjustable flow electric valve, thereby improving the accuracy of system flow control and system stability, but also overcomes the problem of continuous rise in liquid level in the economizer caused by low regulation efficiency of the flow control valve by controlling the opening and flow of the adjustable flow electric valve, thereby improving the stability and reliability of the economizer and preventing liquid carryover during gas replenishment caused by excessively high liquid level in the economizer.

[0024] In some specific embodiments, an economizer is also included, which is located on the main liquid line and includes a gas supply port; the gas supply port is connected to the compressor to supply gas to the compressor;

[0025] The flow control valve includes a first flow control valve and a second flow control valve; the throttling element is a throttling orifice plate, including a first throttling element and a second throttling element; the first flow control valve and the first throttling element are connected in series between the condenser and the economizer to form a first throttling device; the second flow control valve and the second throttling element are connected in series between the economizer and the evaporator to form a second throttling device;

[0026] One end of the first throttling device and one end of the second flow control valve are respectively connected to the inlet and outlet of the economizer; the adjustable flow electric valve is connected in parallel with the first throttling device.

[0027] In this embodiment, the chiller unit connects a first throttling device, which is formed by a first flow control valve connected in series with a first throttling element, through a bypass regulating branch consisting of an adjustable flow electric valve and pipeline. This device corrects the flow curve of the first flow control valve and solves the problem of the narrow applicable operating range of the fixed orifice plate of the first throttling element when the chiller unit is operating under low pressure ratio conditions, thereby improving system efficiency.

[0028] In some specific embodiments, an economizer is also included, which is located on the main liquid line and includes a gas supply port; the gas supply port is connected to the compressor to supply gas to the compressor;

[0029] The flow control valve includes a first flow control valve and a second flow control valve; the throttling element is a throttling orifice plate, including a first throttling element and a second throttling element; the first flow control valve and the first throttling element are connected in series between the condenser and the economizer; the second flow control valve and the second throttling element are connected in series between the economizer and the evaporator;

[0030] One end of the first throttling device and one end of the second flow control valve are respectively connected to the inlet and outlet of the economizer; the common end of the outlet and the second flow control valve, and the common end of the second throttling device and the evaporator are respectively connected to the two ends of the adjustable flow electric valve through pipelines.

[0031] In this embodiment, the chiller unit achieves flow compensation and regulation of the second flow control valve and the second throttling device by setting a bypass regulating branch connected in parallel with the second throttling device, thereby directly providing liquid refrigerant to the evaporator and improving the accuracy of liquid level control and refrigeration efficiency in the evaporator.

[0032] In some specific embodiments, an economizer is also included, which is located on the main liquid line and includes a gas supply port; the gas supply port is connected to the compressor to supply gas to the compressor;

[0033] The throttling device is a throttling orifice plate, including a first throttling device and a second throttling device; the flow control valve, the first throttling device, the economizer, and the second throttling device are connected in series between the condenser and the evaporator;

[0034] The common end of the condenser and the flow control valve, and the common end of the economizer and the second throttling element are respectively connected to the two ends of the adjustable flow electric valve through pipelines.

[0035] In this embodiment, the chiller unit uses a bypass regulating branch formed by a flow control valve and an adjustable flow electric valve connected to the main liquid line. This bypass branch, connected in parallel with the flow control valve, the first throttling element, and the economizer, not only corrects the flow curve of the flow control valve and better adapts to low pressure ratio conditions, but also addresses the issue of the economizer level continuously rising due to significant operating conditions. Normal adjustment of the flow control valve cannot promptly lower the economizer level. By controlling the adjustable flow electric valve, its opening can be increased to bypass some liquid, reducing the liquid flow into the economizer and preventing the compressor from being damaged by excessively rapid rise in the economizer level. Furthermore, the adjustable flow electric valve can regulate the economizer level and the flow rate in the economizer outlet pipeline, eliminating the need for a flow control valve between the economizer and the evaporator, thus reducing costs.

[0036] In some specific embodiments, the first throttling element and / or the second throttling element are throttling orifice plates.

[0037] In this embodiment, the chiller unit reduces costs by using orifice plates for both the first and second throttling components.

[0038] In some specific embodiments, the flow control valve is a V-port electric ball valve.

[0039] This embodiment uses a V-port electric ball valve as a flow control valve to improve the flow regulation range and meet the needs of the chiller unit for large flow and high power.

[0040] In some specific embodiments, the adjustable flow electric valve is an electronic expansion valve.

[0041] In this embodiment, the chiller unit improves the regulation accuracy of the bypass regulation branch by using an adjustable flow electric valve and an electronic expansion valve with high regulation accuracy, thereby improving the efficiency and accuracy of flow control.

[0042] Other features and advantages of this utility model will become clearer after reading the detailed embodiments of this utility model in conjunction with the accompanying drawings. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of the composition and connection structure of the chiller unit system according to an embodiment;

[0045] Figure 2 This is a schematic diagram of the composition and connection structure of the chiller unit system according to an embodiment;

[0046] Figure 3 This is a schematic diagram of the composition and connection structure of the chiller unit system according to an embodiment;

[0047] Figure 4 This is a schematic diagram of the composition and connection structure of the chiller unit system according to an embodiment;

[0048] Figure 5 This is a schematic diagram of the composition and connection structure of the chiller unit system according to an embodiment;

[0049] Figure 6 This is a schematic diagram of the composition and connection structure of the chiller unit system according to an embodiment;

[0050] Figure 7 This is a schematic diagram showing the flow rate of the flow control valve according to an embodiment as a function of the valve opening degree.

[0051] Figure 8 This is a schematic diagram of the electrical composition and connection structure of the chiller unit according to an embodiment;

[0052] Figure 9 This is a schematic diagram of the electrical composition and connection structure of the chiller unit according to an embodiment;

[0053] Figure 10 This is a schematic diagram of the electrical composition and connection structure of a chiller unit according to an embodiment.

[0054] Figure label,

[0055] 1. Compressor; 2. Condenser; 3. Evaporator; 4. Flow control valve; 41. First flow control valve; 42. Second flow control valve; 51. First throttling element; 52. Second throttling element; 6. Adjustable flow electric valve; 7. Economizer; 71. Gas inlet; 72. Liquid inlet; 73. Liquid outlet; 8. Controller; 91. High pressure detection unit; 92. Low pressure detection unit; 101. First liquid level detection unit; 102. Second liquid level detection unit. Detailed Implementation

[0056] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0057] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0058] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0059] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0060] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0061] The following disclosure provides many different embodiments or examples for implementing various structures of this invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0062] Air conditioners execute a refrigeration cycle using a compressor, condenser, throttling device, and evaporator. The refrigeration cycle involves a series of processes, including compression, condensation, expansion, and evaporation, to cool or heat an indoor space.

[0063] Low-temperature, low-pressure refrigerant enters the compressor, which compresses it into a high-temperature, high-pressure refrigerant gas and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process.

[0064] The throttling device reduces the high-temperature, high-pressure liquid refrigerant that condenses in the condenser to a low-pressure liquid refrigerant. The evaporator evaporates the refrigerant throttled in the throttling device and returns the low-temperature, low-pressure refrigerant gas to the compressor. The evaporator achieves its cooling effect by utilizing the latent heat of refrigerant evaporation to exchange heat with the material being cooled.

[0065] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 The chiller unit of this utility model is an air conditioner with a special structure and special function; that is, the chiller unit includes a two-stage compressor 1, a condenser 2 that exchanges heat with the refrigerant, and an evaporator 3, which are connected by pipelines to form a refrigeration cycle system to provide cooling capacity to the indoor space or the refrigerant; the refrigeration cycle system applies energy to the refrigerant vapor through the compressor 1, causing its pressure and temperature to rise. After condensation and throttling, it becomes a low-pressure liquid refrigerant. The low-pressure liquid refrigerant evaporates in the evaporator 3, and at the same time absorbs heat from the surrounding environment (refrigerant, such as water) to lower the temperature of the refrigerant, thereby achieving the purpose of cooling.

[0066] Specifically, the chiller unit also includes an economizer 7; the compressor 1 adjusts the amount of refrigerant entering the compressor 1 by adjusting the frequency and the opening of the inlet guide vanes. The low-temperature, low-pressure gaseous refrigerant evaporated from the evaporator 3 is compressed by the first-stage impeller of the compressor 1, then mixed with the medium-temperature, medium-pressure saturated gas from the economizer 7 and further compressed by the second-stage impeller, becoming a high-temperature, high-pressure gaseous refrigerant. This gaseous refrigerant then enters the condenser 2, where it is cooled by the cooling water and transformed into a high-temperature, high-pressure liquid refrigerant. The high-temperature, high-pressure liquid refrigerant, after being throttled and depressurized in the first stage, enters the economizer 7, where it is separated into saturated liquid refrigerant and flashing gaseous refrigerant. The gaseous refrigerant enters the second-stage impeller of the compressor 1 through the make-up gas line for further compression; the liquid refrigerant, after being throttled and depressurized in the second stage, becomes a low-temperature, low-pressure liquid refrigerant and enters the evaporator 3, forming the main circulation loop.

[0067] The chiller unit of this utility model also includes a flow control valve 4, whose flow rate changes non-linearly with the opening degree, and is installed on the main liquid line between the condenser 2 and the evaporator 3.

[0068] The chiller unit also includes a throttling device, which is installed on the main liquid line and together with the flow control valve 4 forms a throttling device to throttle and reduce the pressure of the refrigerant output from the condenser 2.

[0069] The chiller unit also includes an adjustable flow electric valve 6, whose diameter is smaller than that of the flow control valve 4. Both ends are connected to refrigerant pipelines to form a bypass regulating branch located between the condenser 2 and the evaporator 3. It is used to adjust the flow through the adjustable flow electric valve 6 by adjusting the opening of the adjustable flow electric valve 6 to compensate for or correct the flow regulation of the flow control valve 4.

[0070] The chiller unit of this invention features an adjustable flow bypass regulating branch in the main liquid circuit, which is linked to the flow control valve 4 in the main liquid circuit. The regulating accuracy of the bypass regulating branch is higher than that of the flow control valve 4. This allows for coarse adjustment via the flow control valve 4 and fine adjustment via the adjustable flow electric valve 6 during flow regulation. This compensates for under-adjustment or over-adjustment caused by the nonlinear change in flow rate with the opening degree during flow control by the flow control valve 4, overcoming inaccurate flow control and improving the accuracy and consistency of flow regulation. It also accelerates the stabilization of the heat exchanger liquid level and improves the stability and reliability of the system.

[0071] The specific structure and principle of the chiller unit of this utility model will be described and explained in detail below through specific embodiments.

[0072] Reference Figure 1 The economizer 7 includes an air inlet 71, a liquid inlet 72, and a liquid outlet 73; the economizer 7 is located on the main liquid circuit; the air inlet 71 is connected to the compressor 1 and is used to supply air to the compressor 1 for secondary compression.

[0073] The flow control valve 4 includes a first flow control valve 41 and a second flow control valve 42; the throttling element includes a first throttling element 51 and a second throttling element 52; the first flow control valve 41 and the first throttling element 51 are connected in series between the condenser 2 and the economizer 7 to form a first throttling device for primary throttling; the second flow control valve 42 and the second throttling element 52 are connected in series between the economizer 7 and the evaporator 3 to form a second throttling device for secondary throttling.

[0074] One end of the first throttling element 51 and one end of the second flow control valve 42 are respectively connected to the liquid inlet 72 and the liquid outlet 73 of the economizer 7; that is, the first flow control valve 41, the first throttling element 51, the economizer 7, the second flow control valve 42, and the second throttling element 52 are connected in series in the main liquid path between the condenser 2 and the evaporator 3.

[0075] The adjustable flow electric valve 6 is connected in parallel with the first flow control valve 41; that is, the common end of the condenser 2 and the first flow control valve 41, and the common end of the first flow control valve 41 and the first throttling element 51 are respectively connected to the two ends of the adjustable flow electric valve 6 through refrigerant pipelines.

[0076] In this embodiment, the chiller unit connects an adjustable flow electric valve 6, which has a higher adjustment accuracy than the first flow control valve 41, in parallel with the first flow control valve 41. This allows the flow rate of the first flow control valve 41 to be compensated or corrected by adjusting the opening of the adjustable flow electric valve 6. This overcomes the problem of under-adjustment or over-adjustment caused by the nonlinear change of flow rate with opening during the flow control process, thereby improving the accuracy and consistency of flow regulation. It also accelerates the stabilization of the heat exchanger liquid level and improves the stability and reliability of the system.

[0077] In some specific embodiments, refer to Figure 1 , Figure 9 The chiller unit also includes a controller 8 and a first liquid level detection unit 101; the first liquid level detection unit 101 is installed in the economizer 7 and connected to the controller 8, and is used to detect the first liquid level signal in the economizer 7 and transmit it to the controller 8.

[0078] The controller 8 is connected to the first flow control valve 41 and is configured to control the opening degree of the first flow control valve 41 using a PID control method based on the received first liquid level signal.

[0079] In some specific embodiments, refer to Figure 1 , Figure 9 The controller 8 is connected to the adjustable flow electric valve 6 to control its opening degree.

[0080] The controller 8 presets an opening threshold. An opening exceeding the opening threshold is a large opening, and an opening below the opening threshold is a small opening. The controller 8 is configured to control the adjustable flow electric valve 6 to increase its opening when the first flow control valve 41 is at a small opening and the opening is increased, and to control the adjustable flow electric valve 6 to decrease its opening when it is at a large opening and the opening is increased. When the opening threshold is reached, the adjustable flow electric valve 6 is controlled to have the maximum opening.

[0081] In this embodiment, the chiller unit controls the adjustable flow electric valve 6 to open when the first flow control valve 41 is at a small opening, making the flow curve linearity of the first flow control valve 41 at a small opening close to that at a large opening. When the first flow control valve 41 is at a large opening and the opening is increased, the opening of the adjustable flow electric valve 6 is reduced, reducing the flow rate change rate of the first flow control valve 41 at a large opening. This corrects the flow curve of the first flow control valve 41, making it close to a linear adjustment relationship with equal proportion. Therefore, when using PID control to adjust the valve opening to correct the heat exchanger liquid level, the target liquid level can be achieved more accurately and quickly, avoiding continuous oscillations in the liquid level and improving the stability and efficiency of flow control.

[0082] In some specific embodiments, refer to Figure 1 , Figure 10 The chiller unit also includes a second liquid level detection unit 102, which is installed in the evaporator 3 and connected to the controller 8. It is used to detect the second liquid level signal in the evaporator 3 and transmit it to the controller 8. The controller 8 is configured to control the opening degree of the second flow control valve 42 according to the received second liquid level signal using a PID control method.

[0083] In some specific embodiments, refer to Figure 2 The economizer 7 includes an air inlet 71, a liquid inlet 72, and a liquid outlet 73; the air inlet 71 is connected to the compressor 1 and provides air for the secondary compression of the compressor 1.

[0084] The flow control valve includes a first flow control valve 41 and a second flow control valve 42; the throttling element includes a first throttling element 51 and a second throttling element 52; the first flow control valve 41 and the first throttling element 51 are connected in series between the condenser 2 and the economizer 7 to form a first throttling device for primary throttling; the second flow control valve 42 and the second throttling element 52 are connected in series between the economizer 7 and the evaporator 3 to form a second throttling device for secondary throttling.

[0085] One end of the first throttling element 51 and one end of the second flow control valve 42 are respectively connected to the inlet 72 and outlet 73 of the economizer 7; that is, the first flow control valve 41, the first throttling element 51, the economizer 7, the second flow control valve 42, and the second throttling element 52 are connected in series in the main liquid line between the condenser 2 and the evaporator 3; the common end of the outlet 73 of the economizer 7 and the second flow control valve 42, and the common end of the second flow control valve 42 and the second throttling element 52 are respectively connected to the two ends of the adjustable flow electric valve 6 through pipelines.

[0086] In this embodiment, the chiller unit overcomes the problem of nonlinear flow variation caused by the opening of the adjustable flow electric valve 6 and the flow compensation second flow control valve 42 by adjusting the opening degree of the adjustable flow electric valve 6 and the flow regulation of the flow, thereby improving the accuracy of system flow control and the stability and accuracy of the liquid level in the evaporator 3, and improving the system cooling efficiency.

[0087] In some specific embodiments, refer to Figure 3 The economizer 7 includes an air inlet 71, a liquid inlet 72, and a liquid outlet 73; the air inlet 71 is connected to the compressor 1 and provides air for the secondary compression of the compressor 1.

[0088] The throttling device includes a first throttling device 51 and a second throttling device 52; the flow control valve 4, the first throttling device 51, the economizer 7, and the second throttling device 52 are connected in series between the condenser 2 and the evaporator 3; that is, one end of the first throttling device 51 and one end of the second throttling device 52 are respectively connected to the liquid inlet 72 and the liquid outlet 73 of the economizer 7.

[0089] The common end of the condenser 2 and the flow control valve 4, and the common end of the second throttling element 52 and the evaporator 3 are respectively connected to the two ends of the adjustable flow electric valve 6 through pipelines.

[0090] In this embodiment, the chiller unit not only compensates for the flow regulation of the flow control valve 4 by using the adjustable flow electric valve 6, thereby improving the accuracy of system flow control and system stability, but also overcomes the problem of continuous rise in liquid level in economizer 7 caused by low regulation efficiency of flow control valve 4 by controlling the opening degree and flow of the adjustable flow electric valve 6, thereby improving the stability and reliability of economizer 7 and preventing liquid carryover caused by excessive liquid level in economizer 7.

[0091] In some specific embodiments, refer to Figure 1 , Figure 2 , Figure 3 The throttling element is a throttling orifice plate.

[0092] In some specific embodiments, refer to Figure 4 The economizer 7 includes an air inlet 71, a liquid inlet 72, and a liquid outlet 73; the air inlet 71 is connected to the compressor 1 and provides air for the secondary compression of the compressor 1.

[0093] The flow control valve 4 includes a first flow control valve 41 and a second flow control valve 42; the throttling element is a throttling orifice plate, including a first throttling element 51 and a second throttling element 52; the first flow control valve 41 and the first throttling element 51 are connected in series between the condenser 2 and the economizer 7 to form a first throttling device for primary throttling; the second flow control valve 42 and the second throttling element 52 are connected in series between the economizer 7 and the evaporator 3 to form a second throttling device for secondary throttling.

[0094] One end of the first throttling element 51 and one end of the second flow control valve 42 are respectively connected to the liquid inlet 72 and the liquid outlet 73 of the economizer 7; that is, the first flow control valve 41, the first throttling element 51, the economizer 7, the second flow control valve 42, and the second throttling element 52 are connected in series in the main liquid line between the condenser 2 and the evaporator 3; the common end of the condenser 2 and the first flow control valve 41, and the common end of the first throttling element 51 and the liquid inlet 72 of the economizer 7 are respectively connected to both ends of the adjustable flow electric valve 6 through pipelines; that is, the bypass regulating branch formed by the adjustable flow electric valve 6 and the pipeline is connected in parallel with the first throttling device.

[0095] In this embodiment, the chiller unit connects a first throttling device, which is formed by a first flow control valve 41 connected in series with a first throttling element 51, through a bypass regulating branch consisting of an adjustable flow electric valve 6 and pipelines. This device corrects the flow curve of the first flow control valve 41 and solves the problem of the narrow applicable operating range of the fixed orifice plate of the first throttling element 51 when the chiller unit is operating under low pressure ratio conditions, thereby improving system efficiency.

[0096] The specific principle is as follows: to ensure the efficient and stable operation of the chiller unit under common operating conditions, the orifice plate of the first throttling element 51 is designed primarily based on common operating conditions. Therefore, the fixed orifice plate of the first throttling element 51 may experience insufficient flow capacity under low pressure ratio conditions. In this embodiment, the connection method of the adjustable flow electric valve 6 increases the flow area of ​​the first throttling element 51, enabling it to have sufficient liquid refrigerant flow capacity even under low pressure ratio conditions.

[0097] In some specific embodiments, refer to Figure 8 The chiller unit also includes a controller 8, which is connected to an adjustable flow electric valve 6 to control its opening degree.

[0098] The chiller unit also includes a high-pressure detection unit 91 and a low-pressure detection unit 92, which are respectively installed on the high-pressure pipeline and the low-pressure pipeline and connected to the controller 8, for detecting the high-pressure and low-pressure and transmitting the data to the controller 8.

[0099] The controller 8 is preset with a pressure ratio threshold and is configured to obtain a pressure ratio value based on the obtained high pressure and low pressure. When the pressure ratio value is higher than the pressure ratio threshold, the controller controls the adjustable flow electric valve 6 to close the opening. When the pressure ratio value is lower than the pressure ratio threshold, the controller controls the adjustable flow electric valve 6 to increase the opening.

[0100] In some specific embodiments, refer to Figure 5 The economizer 7 includes an air inlet 71, a liquid inlet 72, and a liquid outlet 73; the air inlet 71 is connected to the compressor 1 and provides air for the secondary compression of the compressor 1.

[0101] The flow control valve includes a first flow control valve 41 and a second flow control valve 42; the throttling element is a throttling orifice plate, including a first throttling element 51 and a second throttling element 52; the first flow control valve 41 and the first throttling element 51 are connected in series between the condenser 2 and the economizer 7 to form a first throttling device for primary throttling; the second flow control valve 42 and the second throttling element 52 are connected in series between the economizer 7 and the evaporator 3 to form a second throttling device for secondary throttling.

[0102] One end of the first throttling element 51 and one end of the second flow control valve 42 are respectively connected to the liquid inlet 72 and the liquid outlet 73 of the economizer 7; that is, the first flow control valve 41, the first throttling element 51, the economizer 7, the second flow control valve 42, and the second throttling element 52 are connected in series in the main liquid line between the condenser 2 and the evaporator 3; the common end of the liquid outlet 73 and the second flow control valve 42, and the common end of the second throttling element 52 and the evaporator 3 are respectively connected to both ends of the adjustable flow electric valve 6 through pipelines; that is, the bypass regulating branch composed of the adjustable flow electric valve 6 and the pipeline is connected in parallel with the second throttling device.

[0103] In this embodiment, the chiller unit achieves flow compensation and regulation of the second flow control valve 42 and the second throttling device 52 by setting a bypass regulating branch connected in parallel with the second throttling device, thereby directly providing liquid refrigerant to the evaporator 3 and improving the accuracy of liquid level control and refrigeration efficiency in the evaporator 3.

[0104] In some specific embodiments, refer to Figure 6 The economizer 7 includes an air inlet 71, a liquid inlet 72, and a liquid outlet 73; the air inlet 71 is connected to the compressor 1 and provides air for the secondary compression of the compressor 1.

[0105] The throttling device is a throttling orifice plate, including a first throttling device 51 and a second throttling device 52; the flow control valve 4, the first throttling device 51, the economizer 7, and the second throttling device 52 are connected in series between the condenser 2 and the evaporator 3; one end of the first throttling device 51 and one end of the second throttling device 52 are connected to the liquid inlet 72 and the liquid outlet 73 of the economizer 7, respectively; the common end of the condenser 2 and the flow control valve 4, and the common end of the second throttling device 52 and the liquid outlet 73 of the economizer 7 are connected to both ends of the adjustable flow electric valve 6 through pipelines; that is, the bypass regulating branch composed of the adjustable flow electric valve 6 and the pipeline is connected in parallel with the first throttling device and the economizer 7.

[0106] In this embodiment, the chiller unit uses a bypass regulating branch formed by a flow control valve 4 and an adjustable flow electric valve 6 connected to the main liquid line. This bypass branch, connected in parallel with the flow control valve 4, the first throttling element 51, and the economizer 7, not only corrects the flow curve of the flow control valve 4 and better adapts to low pressure ratio conditions, but also, when the operating conditions fluctuate significantly and the liquid level in the economizer 7 continuously rises, the flow control valve 4 cannot reduce the liquid level in the economizer 7 in time under normal adjustment. By controlling the adjustable flow electric valve 6, the opening of the adjustable flow electric valve 6 can be increased in time, allowing some liquid to bypass the economizer 7, reducing the liquid flow entering the economizer 7, and preventing the liquid level in the economizer 7 from rising too quickly and causing damage to the compressor 1 due to liquid carryover during gas injection. In addition, the adjustable flow electric valve 6 can regulate the liquid level in the economizer 7 and the flow rate in the outlet pipe of the economizer 7, eliminating the need for the flow control valve 4 between the economizer 7 and the evaporator 3, thus reducing costs.

[0107] In some specific embodiments, refer to Figure 9 The chiller unit uses a PID control method to control the opening of the flow control valve 4 based on the first liquid level signal. Furthermore, as the first liquid level signal continues to rise, it controls the adjustable flow electric valve 6 to increase its opening.

[0108] In some specific embodiments, refer to Figure 7 Flow control valve 4 is a V-port electric ball valve; Figure 8 The curve showing the flow rate at 60°V port as a function of valve opening; from Figure 8 It can be seen that the flow rate of flow control valve 4 changes non-linearly with the valve opening.

[0109] In this embodiment, the flow control valve 4 of the V-port electric ball valve is used to improve the flow regulation range and meet the needs of the chiller unit for large flow and high power.

[0110] In some specific embodiments, refer to Figure 9 , Figure 10 The adjustable flow electric valve 6 adopts an electronic expansion valve, which has high adjustment accuracy and improves the efficiency and accuracy of flow control.

[0111] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0112] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A chiller unit, comprising a compressor, a condenser, and an evaporator, connected by pipelines to form a refrigeration cycle system; characterized in that, Also includes: A flow control valve, whose flow rate changes non-linearly with the opening degree, is installed on the pipeline between the condenser and the evaporator to form the main liquid path; A throttling element is installed on the main liquid line and together with the flow control valve, forms a throttling device. An adjustable flow electric valve, with a smaller orifice than the flow control valve, forms a bypass regulating branch located between the condenser and the evaporator, used to compensate for the flow regulation of the flow control valve by adjusting the opening of the adjustable flow electric valve.

2. The chiller unit according to claim 1, characterized in that, It also includes an economizer, which is located on the main liquid line and includes a gas supply port; the gas supply port is connected to the compressor and is used to supply gas to the compressor; The flow control valve includes a first flow control valve and a second flow control valve; the throttling element includes a first throttling element and a second throttling element; the first flow control valve and the first throttling element are connected in series between the condenser and the economizer; the second flow control valve and the second throttling element are connected in series between the economizer and the evaporator; One end of the first throttling element and one end of the second flow control valve are respectively connected to the inlet and outlet of the economizer; the adjustable flow electric valve is connected in parallel with the first flow control valve.

3. The chiller unit according to claim 1, characterized in that, It also includes an economizer, which is located on the main liquid line and includes a gas supply port; the gas supply port is connected to the compressor to supply gas to the compressor; The flow control valve includes a first flow control valve and a second flow control valve; the throttling element includes a first throttling element and a second throttling element; the first flow control valve and the first throttling element are connected in series between the condenser and the economizer; the second flow control valve and the second throttling element are connected in series between the economizer and the evaporator; One end of the first throttling device and one end of the second flow control valve are respectively connected to the inlet and outlet of the economizer; the common end of the outlet and the second flow control valve, and the common end of the second flow control valve and the second throttling device are respectively connected to the two ends of the adjustable flow electric valve through pipelines.

4. The chiller unit according to claim 1, characterized in that, It also includes an economizer, which is located on the main liquid line and includes a gas supply port; the gas supply port is connected to the compressor to supply gas to the compressor; The throttling device includes a first throttling device and a second throttling device; the flow control valve, the first throttling device, the economizer, and the second throttling device are connected in series between the condenser and the evaporator; The common end of the condenser and the flow control valve, and the common end of the second throttling element and the evaporator are respectively connected to the two ends of the adjustable flow electric valve through pipelines.

5. The chiller unit according to claim 1, characterized in that, It also includes an economizer, which is located on the main liquid line and includes a gas supply port; the gas supply port is connected to the compressor to supply gas to the compressor; The flow control valve includes a first flow control valve and a second flow control valve; the throttling element is a throttling orifice plate, including a first throttling element and a second throttling element; the first flow control valve and the first throttling element are connected in series between the condenser and the economizer to form a first throttling device; the second flow control valve and the second throttling element are connected in series between the economizer and the evaporator to form a second throttling device; One end of the first throttling device and one end of the second flow control valve are respectively connected to the inlet and outlet of the economizer; the adjustable flow electric valve is connected in parallel with the first throttling device.

6. The chiller unit according to claim 1, characterized in that, It also includes an economizer, which is located on the main liquid line and includes a gas supply port; the gas supply port is connected to the compressor to supply gas to the compressor; The flow control valve includes a first flow control valve and a second flow control valve; the throttling element is a throttling orifice plate, including a first throttling element and a second throttling element; the first flow control valve and the first throttling element are connected in series between the condenser and the economizer; the second flow control valve and the second throttling element are connected in series between the economizer and the evaporator; One end of the first throttling device and one end of the second flow control valve are respectively connected to the inlet and outlet of the economizer; the common end of the outlet and the second flow control valve, and the common end of the second throttling device and the evaporator are respectively connected to the two ends of the adjustable flow electric valve through pipelines.

7. The chiller unit according to claim 1, characterized in that, It also includes an economizer, which is located on the main liquid line and includes a gas supply port; the gas supply port is connected to the compressor to supply gas to the compressor; The throttling device is a throttling orifice plate, including a first throttling device and a second throttling device; the flow control valve, the first throttling device, the economizer, and the second throttling device are connected in series between the condenser and the evaporator; The common end of the condenser and the flow control valve, and the common end of the economizer and the second throttling element are respectively connected to the two ends of the adjustable flow electric valve through pipelines.

8. The chiller unit according to any one of claims 2 to 4, characterized in that, The first throttling element and / or the second throttling element are throttling orifice plates.

9. The chiller unit according to any one of claims 1 to 7, characterized in that, The flow control valve is a V-port electric ball valve.

10. The chiller unit according to any one of claims 1 to 7, characterized in that, The adjustable flow electric valve is an electronic expansion valve.

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