Energy-saving direct expansion liquid supply refrigeration system and tube ice machine

Abstract

This utility model relates to the field of refrigeration technology, and discloses an energy-saving direct expansion liquid supply refrigeration system and a tube ice machine. The system includes a compressor, a condenser, an evaporator, and a throttling valve, connected sequentially by pipes. A reflux-type gas-liquid separator is provided between the evaporator and the compressor, with its bottom return port connected to the evaporator to achieve liquid refrigerant circulation. When liquid refrigerant accumulates in the reflux-type gas-liquid separator, it flows back to the evaporator by gravity through the bottom return port, achieving near-zero superheat throttling. This utility model overcomes the limitations of superheat, allowing the evaporator to receive a significantly increased amount of refrigerant, thus improving heat exchange efficiency. Simultaneously, through liquid refrigerant circulation and intelligent temperature control, it solves problems of high energy consumption, reflux blockage, and low-temperature freezing. Furthermore, this utility model also discloses a tube ice machine using this energy-saving direct expansion liquid supply refrigeration system.

Description

Technical Field

[0001] This utility model relates to the field of refrigeration technology, and in particular to an energy-saving direct expansion liquid supply refrigeration system and a tube ice machine. Background Technology

[0002] Direct expansion refrigerant supply systems are widely used in small and medium-sized refrigeration projects due to their advantages such as system simplicity, low refrigerant charge, and low cost. However, this type of system suffers from high energy consumption, especially in large-scale refrigeration projects, where its high energy consumption significantly increases operating costs.

[0003] This is because, in existing technologies, refrigeration systems typically rely on thermostatic expansion valves to control suction superheat and prevent compressor liquid slugging. However, this method can easily lead to the accumulation of liquid refrigerant in the gas-liquid separator, forcing the refrigeration system to maintain a high superheat. Excessive superheat not only reduces the heat exchange efficiency of the evaporator but also raises the compressor's suction temperature, resulting in decreased refrigeration efficiency and ultimately a low energy efficiency ratio for the refrigeration system. Utility Model Content

[0004] This utility model discloses an energy-saving direct expansion liquid supply refrigeration system, which enables the refrigeration system to operate without maintaining a high superheat, thereby improving the heat exchange efficiency and energy efficiency ratio of the evaporator.

[0005] To achieve the above objectives, in a first aspect, this application discloses an energy-saving direct expansion liquid supply refrigeration system, comprising:

[0006] compressor;

[0007] A condenser, wherein the condenser piping is connected to the compressor;

[0008] An evaporator, wherein the evaporator piping is connected to the condenser;

[0009] A throttling valve is installed on the pipeline connecting the evaporator and the condenser;

[0010] A reflux gas-liquid separator is provided, wherein the reflux gas-liquid separator pipe is connected between the evaporator and the compressor. The reflux gas-liquid separator is used to separate the gas-liquid mixture of refrigerant discharged from the evaporator, so as to deliver the separated gaseous refrigerant to the compressor. The reflux gas-liquid separator is provided with a reflux port, and the reflux port pipe is connected to the evaporator, so as to return the liquid refrigerant in the reflux gas-liquid separator to the evaporator, so that the opening degree of the throttle valve is adjusted independently of the superheat of the refrigerant at the evaporator outlet.

[0011] The refrigeration system disclosed in this application employs a reflux-type gas-liquid separator with a reflux port connected to the evaporator. This allows the separated liquid refrigerant to flow back to the evaporator and re-enter the circulation, preventing the accumulation of liquid refrigerant in the reflux-type gas-liquid separator and avoiding the risk of liquid slugging in the compressor. Furthermore, it eliminates the need to rely on a throttle valve to control superheat for protection. In other words, the opening of the throttle valve in this refrigeration system can be adjusted independently of the superheat of the refrigerant at the evaporator outlet. This means the throttle valve opening does not need to be adjusted based on the superheat of the refrigerant at the evaporator outlet, allowing the evaporator to receive a significantly higher refrigerant circulation volume, thus improving the evaporator's heat exchange efficiency. In addition, this method reduces the compressor suction superheat, effectively improving the compressor's refrigeration efficiency and consequently increasing the energy efficiency ratio of the refrigeration system.

[0012] As an optional implementation, the reflux port is located at the bottom of the reflux gas-liquid separator, and the top of the reflux gas-liquid separator is provided with a liquid inlet and a gas outlet. The liquid inlet pipe is connected to the evaporator so that the gas-liquid mixed refrigerant discharged from the evaporator enters the separation chamber for gas-liquid separation. The gas outlet pipe is connected to the compressor for delivering the separated gaseous refrigerant to the compressor.

[0013] By placing the reflux port of the reflux-type gas-liquid separator at the bottom and the liquid inlet and gas outlet at the top, the gas-liquid mixture discharged from the evaporator can smoothly enter the reflux-type gas-liquid separator through the liquid inlet at the top, thus enabling thorough gas-liquid separation. The gas outlet at the top allows the separated gaseous refrigerant to exit, thereby reducing the amount of liquid droplets entrained in the gaseous refrigerant and lowering the risk of the compressor drawing in droplets. The reflux port at the bottom precisely collects the separated liquid refrigerant, providing a path for the liquid refrigerant to flow back to the evaporator, further optimizing the gas-liquid separation effect, and thus improving the compressor's suction quality and the efficiency of liquid refrigerant reflux.

[0014] As an optional implementation, the reflux gas-liquid separator is installed at a height higher than the evaporator in the vertical direction, so that the reflux port is located above the evaporator in the vertical direction, so as to reflux the liquid refrigerant back to the evaporator.

[0015] By setting the vertical installation height of the reflux gas-liquid separator to be higher than that of the evaporator, the separated liquid refrigerant can naturally flow back to the evaporator from the bottom reflux port through the pipe by its own gravity. This eliminates the need for additional power devices such as pumps, simplifies the structure of the refrigeration system, and reduces equipment costs and operating energy consumption.

[0016] As an optional implementation, a check valve is provided on the pipeline connecting the return port to the evaporator. The check valve is used to prevent the gaseous refrigerant in the evaporator from flowing back into the reflux gas-liquid separator.

[0017] Installing a check valve on the liquid refrigerant outlet pipe effectively prevents gaseous refrigerant in the evaporator from flowing back into the reflux gas-liquid separator under pressure fluctuations, ensuring that liquid refrigerant can only flow unidirectionally from the reflux gas-liquid separator to the evaporator. This design avoids gaseous refrigerant mixing into the liquid refrigerant backflow path within the reflux gas-liquid separator, preventing the decrease in reflux efficiency caused by gaseous refrigerant interference, ensuring the stability of liquid refrigerant reflux, further enhancing the gas-liquid separation effect, and helping to reduce the probability of refrigeration system malfunctions.

[0018] As an optional implementation, the reflux gas-liquid separator is provided with heat exchange tubes, and the energy-saving direct expansion liquid supply refrigeration system further includes a liquid receiver. The liquid receiver is connected to the output port of the condenser, and the liquid receiver is also connected to the heat exchange tubes of the reflux gas-liquid separator to introduce refrigerant into the heat exchange tubes to heat the reflux gas-liquid separator.

[0019] By installing heat exchange tubes in a reflux gas-liquid separator, and connecting these tubes to a liquid receiver and circulating refrigerant, the refrigerant's temperature is used to heat the reflux gas-liquid separator. This prevents the refrigerant from freezing or increasing in viscosity due to excessively low temperatures, which could block the gas-liquid separation channels or reflux ports under low-temperature refrigeration conditions. Furthermore, heating the reflux gas-liquid separator ensures good refrigerant flow, maintaining gas-liquid separation efficiency and smooth refrigerant reflux. This, in turn, improves the refrigeration system's adaptability and continuous operation in low-temperature environments.

[0020] As an optional implementation, the energy-saving direct expansion refrigerant supply refrigeration system further includes a temperature sensor, which is installed on the pipeline connecting the evaporator and the reflux gas-liquid separator to monitor the temperature of the refrigerant when it leaves the evaporator.

[0021] A temperature sensor is installed on the pipeline connecting the evaporator and the reflux gas-liquid separator to monitor the temperature of the refrigerant as it leaves the evaporator in real time, providing crucial data support for the regulation of the refrigeration system's operation. By monitoring temperature changes, the control module can promptly determine the evaporator's heat exchange efficiency, whether the refrigerant flow rate matches the refrigeration demand, and other factors. This allows for dynamic adjustment of parameters such as the opening of the expansion valve and the compressor's operating power, ensuring the evaporator is always in a highly efficient refrigeration state. It also facilitates the timely detection of refrigeration system anomalies (such as abnormal temperature fluctuations), improving the operability and operational stability of the refrigeration system.

[0022] As an optional implementation, the rated power of the refrigeration system is greater than 50kW. That is, the energy-saving direct expansion refrigerant supply refrigeration system of this application can be applied to the high-load demands of large-scale refrigeration projects. Combined with energy-saving structures such as zero superheat throttling or minimal superheat throttling and efficient liquid refrigerant reflux, it can fully leverage its energy-saving advantages in high-energy-consumption scenarios of large-scale refrigeration projects. This solves the problem that direct expansion refrigerant supply systems in related technologies are difficult to apply to large-scale refrigeration projects due to excessive energy consumption, providing an energy-saving and economical solution for large-scale refrigeration projects.

[0023] Secondly, this application also discloses a tube ice machine, which includes an ice maker and an energy-saving direct expansion liquid supply refrigeration system as described in the first aspect, wherein the evaporator of the refrigeration system is disposed in the ice maker.

[0024] The tube ice machine adopts the energy-saving direct expansion liquid supply refrigeration system described in the first aspect, enabling the ice-making process to fully utilize the energy-saving advantages of this refrigeration system. Specifically, by using a reflux-type gas-liquid separator to achieve liquid refrigerant reflux and near-zero superheat throttling, the heat exchange efficiency of the ice maker is improved, accelerating the ice-making speed. Simultaneously, the reduced energy consumption of the refrigeration system effectively reduces the electricity costs of the tube ice machine's production. Combined with a stable refrigeration cycle, this ensures uniform and stable ice quality, thereby effectively improving the production efficiency and economy of the tube ice machine in large-scale refrigeration projects.

[0025] As an optional implementation, the ice maker is provided with an ice outlet, and the tube ice machine also includes a de-icing pipeline. One end of the de-icing pipeline is connected to the outlet of the liquid reservoir, and the other end of the de-icing pipeline is connected to the ice maker. The de-icing pipeline is used to transport the refrigerant in the liquid reservoir to the ice maker during the de-icing stage, so that the ice strips produced by the ice maker can be separated from the ice maker and discharged from the ice outlet.

[0026] By installing a de-icing pipeline, refrigerant from the receiver is delivered to the ice maker during the de-icing stage. The heat from the refrigerant raises the temperature of the ice maker, causing the ice strips to detach from the maker and be discharged from the outlet. This eliminates the need for an additional de-icing heating device; instead, the de-icing function is achieved directly using the refrigerant within the refrigeration system, simplifying the structure of the tube ice machine and reducing equipment costs. Furthermore, using the refrigerant in the receiver results in high de-icing efficiency, quickly detaching the ice strips, reducing de-icing time, and increasing the continuous production capacity of the tube ice machine.

[0027] As an optional implementation, the tube ice machine further includes a control module, and a control valve is provided on the de-icing pipeline. The control module is electrically connected to the throttle valve and the control valve. The control module is configured to control the throttle valve to close during the de-icing stage and to control the control valve to open so that the refrigerant in the liquid receiver can be delivered to the ice maker.

[0028] The control module connects the throttle valve and the control valve of the de-icing pipeline via electrical connection. During the de-icing stage, it controls the throttle valve to close to stop the refrigeration cycle, while simultaneously opening the control valve to allow refrigerant in the receiver to enter the ice maker through the de-icing pipeline. This ensures that the refrigeration and de-icing functions are separated during the de-icing stage, avoiding inefficient energy consumption caused by simultaneous operation of both stages, thus improving energy utilization efficiency. Furthermore, the valve switching control ensures a stable de-icing process, preventing incomplete de-icing or ice strip breakage, thereby improving the de-icing effect and the quality of the pipe ice product.

[0029] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0030] The refrigeration system disclosed in this application employs a reflux-type gas-liquid separator with a reflux port connected to the evaporator. This allows the separated liquid refrigerant to flow back to the evaporator and re-enter the circulation, preventing the accumulation of liquid refrigerant in the reflux-type gas-liquid separator and avoiding the risk of liquid slugging in the compressor. Furthermore, it eliminates the need to rely on a throttle valve to control superheat for protection. In other words, the opening of the throttle valve in this refrigeration system can be adjusted independently of the superheat of the refrigerant at the evaporator outlet. This means the throttle valve opening does not need to be adjusted based on the superheat of the refrigerant at the evaporator outlet, allowing the evaporator to receive a significantly higher refrigerant circulation volume, thereby improving the evaporator's heat exchange efficiency. In addition, this method reduces the compressor suction superheat, effectively improving the compressor's refrigeration efficiency and thus enhancing the energy efficiency ratio of the refrigeration system. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the structure of an energy-saving direct expansion liquid supply refrigeration system disclosed in an embodiment of this application;

[0033] Figure 2 yes Figure 1 Enlarged schematic diagram of point I in the middle;

[0034] Figure 3 yes Figure 1 Enlarged schematic diagram at point II;

[0035] Figure 4 yes Figure 1 Enlarged schematic diagram at point III;

[0036] Figure 5 This is a schematic diagram of the structure of a tube ice machine disclosed in an embodiment of this application.

[0037] Explanation of reference numerals in the attached figures:

[0038] Refrigeration system - 100; Compressor - 1; Condenser - 2; Evaporator - 3; Expansion valve - 4;

[0039] Reflux gas-liquid separator - 5; Reflux port - 51; Liquid inlet - 52; Gas outlet - 53;

[0040] Check valve-6; heat exchange tube-7; liquid reservoir-8; temperature sensor-9;

[0041] Tube ice machine-200; Ice maker-201; De-icing pipeline-202; Ice outlet-203; Control valve-204;

[0042] Control module-205. Detailed Implementation

[0043] 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.

[0044] In this application, the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0045] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0046] Furthermore, the terms "installation," "setting," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; 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, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0047] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0048] As described in the background section of this application, direct expansion refrigerant supply refrigeration systems are widely used in small and medium-sized refrigeration projects due to their simple system structure, low refrigerant charge, and low equipment cost. However, due to high operating energy consumption, this system is difficult to apply to large-scale refrigeration projects, resulting in high energy costs under long-term high-load operation. Furthermore, the main reason for the high energy consumption is that these systems rely on thermostatic expansion valves to control suction superheat to prevent compressor liquid slugging. The accumulation of liquid refrigerant poses a risk of compressor liquid slugging, thus forcing the system to maintain a higher superheat to mitigate this risk. Simultaneously, the increased compressor suction temperature reduces refrigeration efficiency, leading to a lower energy efficiency ratio (EER) for the refrigeration system.

[0049] Based on this, the present invention discloses an energy-saving direct expansion liquid supply refrigeration system, which realizes liquid refrigerant reflux and near-zero superheat throttling through a reflux gas-liquid separator, solves the drawbacks of traditional systems, improves efficiency and reduces energy consumption, and can meet the needs of large-scale refrigeration projects.

[0050] The technical solution of this application will be further described below with reference to specific embodiments and accompanying drawings.

[0051] Please see Figure 1 , Figure 1 This is a schematic diagram of an energy-saving direct expansion refrigerant supply system 100 disclosed in an embodiment of this application. The refrigeration system 100 includes: a compressor 1, a condenser 2, and a pipe connecting the condenser 2 to the compressor 1; an evaporator 3, with a pipe connecting the evaporator 3 to the condenser 2; a throttling valve 4, installed on the pipe connecting the evaporator 3 and the condenser 2; and a reflux gas-liquid separator 5, with a pipe connecting the evaporator 3 and the compressor 1. The reflux gas-liquid separator 5 is used to separate the gas-liquid mixture of refrigerant discharged from the evaporator 3, so as to deliver the separated gaseous refrigerant to the compressor 1. The reflux gas-liquid separator 5 has a reflux port 51, with a pipe connected to the evaporator 3, so as to return the liquid refrigerant in the reflux gas-liquid separator 5 to the evaporator 3. The throttling valve 4 does not need to control the superheat of the return gas.

[0052] Specifically, the refrigeration system 100 of this application achieves the circulation of liquid refrigerant through a reflux-type gas-liquid separator 5, solving the problem of high energy consumption in direct expansion liquid supply systems. In related technologies, the liquid refrigerant separated by conventional gas-liquid separators cannot be effectively returned and tends to accumulate within the separator. To avoid the risk of liquid slugging in the compressor 1, it is necessary to rely on a thermostatic expansion valve to control the return gas superheat for safety. This directly leads to insufficient refrigerant circulation in the evaporator 3, low heat exchange efficiency, and high suction superheat in the compressor 1, resulting in decreased refrigeration efficiency. However, in this refrigeration system 100, through the setting of the reflux-type gas-liquid separator 5, the reflux-type gas-liquid separator 5 guides the separated liquid refrigerant back to the evaporator 3 through the return port 51, so that the liquid refrigerant no longer stagnates in the reflux-type gas-liquid separator, eliminating the risk of liquid slugging in the compressor 1 from the source. Therefore, the throttling valve 4 does not need to bear the function of controlling the return gas superheat, achieving zero superheat or minimal superheat throttling. The technical advantages of zero-superheat throttling or minimal-superheat throttling are significant. Evaporator 3 can obtain a refrigerant with a much larger circulation volume, increasing the contact area and residence time between the refrigerant and the heat exchange surface of evaporator 3, thereby improving the heat exchange efficiency of evaporator 3 and resulting in stronger cooling output. Furthermore, the superheat of the gaseous refrigerant drawn into compressor 1 is reduced, decreasing ineffective power consumption during compression and improving the cooling efficiency of compressor 1. Thus, the overall energy consumption of refrigeration system 100 is significantly reduced, and long-term use can substantially reduce production and operating costs. In addition, since complex superheat control logic is not required, the control flow of refrigeration system 100 is simpler, reducing the probability of failures caused by control parameter misalignment, thereby improving the operational stability of refrigeration system 100.

[0053] Zero superheat throttling or minimal superheat throttling refers to the following: before the refrigerant leaves the evaporator and enters the reflux gas-liquid separator, its temperature is basically the same as or only slightly different from the saturation temperature at the corresponding pressure. Under this condition, the refrigerant in the evaporator does not need to be completely vaporized before entering the separator, allowing more liquid refrigerant to participate in heat exchange, thereby increasing the refrigerant circulation in the evaporator and thus improving the heat exchange efficiency.

[0054] It is understandable that the connecting pipe between the above-mentioned reflux gas-liquid separator 5 and the evaporator 3 can be an insulated pipe, thereby reducing the loss of refrigerant cooling capacity during the reflux process.

[0055] It is understandable that the aforementioned throttle valve 4 can be an electronic expansion valve or a high-pressure expansion valve, etc., which only needs to perform the function of throttling and reducing pressure. The opening degree of the throttle valve 4 does not need to be adjusted according to the superheat of the refrigerant at the evaporator outlet.

[0056] In some embodiments, such as Figure 1 and Figure 2 As shown, the reflux port 51 is located at the bottom of the reflux gas-liquid separator 5, and the top of the reflux gas-liquid separator 5 is provided with a liquid inlet 52 and a gas outlet 53. The liquid inlet 52 is connected to the evaporator 3 so that the gas-liquid mixed refrigerant discharged from the evaporator 3 enters the separation chamber for gas-liquid separation. The gas outlet 53 is connected to the compressor 1 so as to transport the separated gaseous refrigerant to the compressor 1.

[0057] Specifically, the structure, with the liquid inlet 52 and gas outlet 53 located at the top and the return port 51 at the bottom, fully utilizes the density difference and gravity of the gas-liquid mixed refrigerant to create a more efficient separation path. When the gas-liquid mixed refrigerant discharged from the evaporator 3 enters the reflux gas-liquid separator 5 through the top liquid inlet 52, the flow direction is opposite to the direction of gravity. The mixed refrigerant undergoes a deceleration and diffusion process within the separation chamber of the reflux gas-liquid separator. The gaseous refrigerant, due to its lower density, rises and eventually exits through the top gas outlet 53, while the liquid refrigerant, due to its higher density, sinks under gravity and eventually converges at the bottom of the reflux gas-liquid separator, then flows back to the evaporator 3 through the bottom return port 51. This structural design extends the contact time of the gas-liquid mixed refrigerant within the separation chamber, resulting in more thorough separation, effectively reducing the amount of liquid droplets entrained in the gaseous refrigerant, lowering the risk of damage caused by liquid droplets being drawn into the compressor 1, and improving the operational safety of the compressor 1.

[0058] More specifically, the bottom reflux port 51 accurately collects the settled liquid refrigerant, preventing its residue within the chamber. Since the liquid refrigerant naturally converges at the bottom, resistance during the reflux process is reduced, ensuring the liquid refrigerant can return to the evaporator 3 in a timely and stable manner to re-enter the cycle, further improving refrigerant utilization. Furthermore, the layout of the liquid inlet and gas outlet at the top makes the pipe connections more conform to fluid dynamics, reducing the impact when the gas-liquid mixed refrigerant enters the reflux-type gas-liquid separator, minimizing secondary mixing caused by turbulence. The gaseous refrigerant also maintains a stable flow rate when exiting from the top, avoiding the impact of flow rate fluctuations on the compressor 1's suction pressure, thus helping to maintain stable pressure in the refrigeration system 100 and improving overall operating efficiency.

[0059] It is understandable that the above-mentioned reflux gas-liquid separator 5 can be equipped with structures such as guide plates or baffles to further optimize the gas-liquid separation path and enhance the separation effect.

[0060] It is understood that the pipe diameters of the pipes connected to the liquid inlet 52, gas outlet 53, and return port 51 can be designed to match the refrigerant flow rate, and this embodiment does not impose specific limitations on this.

[0061] In some embodiments, such as Figures 1 to 4 As shown, the reflux gas-liquid separator 5 is installed at a higher vertical height than the evaporator 3, so that the reflux port 51 is located above the evaporator 3 in the vertical direction, so as to return the liquid refrigerant to the evaporator 3.

[0062] By vertically positioning the reflux-type gas-liquid separator 5 above the evaporator 3, the return port 51 is naturally positioned above the evaporator 3. Gravity drives the flow of liquid refrigerant, creating a passive reflux mechanism that requires no external power. When the liquid refrigerant accumulates at the bottom of the reflux-type gas-liquid separator 5, it flows naturally along the pipe to the lower-positioned evaporator 3 under gravity. The entire process eliminates the need for pumps or other power devices, fundamentally simplifying the structure of the refrigeration system 100. This design not only reduces equipment procurement costs but also avoids energy consumption during power device operation. Furthermore, the gravity-driven reflux method offers stability. Compared to active reflux relying on mechanical power, the gravity-driven reflux method is unaffected by power supply fluctuations or mechanical failures, maintaining a continuous and uniform refrigerant delivery during refrigeration system 100 operation. This ensures that the separated liquid refrigerant returns to the evaporator 3 in a timely manner to participate in the circulation, maintaining a sufficient supply of refrigerant within the evaporator 3 and guaranteeing a near-zero superheat throttling state. Meanwhile, a stable reflux rate can reduce the impact and turbulence of refrigerant in the pipeline, reduce the risk of secondary mixing of gas and liquid caused by sudden changes in flow rate, and thus indirectly improve the overall efficiency of gas-liquid separation.

[0063] Furthermore, the gravity-driven approach reduces potential points of failure, lowering the frequency and difficulty of equipment maintenance. In addition, the gravity-driven return pipe layout is more flexible, allowing for adjustments to the pipe routing based on actual installation space. Sufficient height difference is all that's needed to meet return requirements, enhancing the adaptability of the refrigeration system 100 in various application scenarios.

[0064] Understandably, an insulation layer can be wrapped around the outside of the pipe connecting the return port and the evaporator to reduce heat exchange of the refrigerant during the return process and prevent the liquid refrigerant from prematurely vaporizing, thus affecting the return effect.

[0065] In some embodiments, please refer to the following: Figures 1 to 4 A check valve 6 is provided on the pipeline connecting the return port 51 and the evaporator 3. The check valve 6 is used to prevent the gaseous refrigerant in the evaporator 3 from flowing back into the reflux gas-liquid separator 5.

[0066] Specifically, during the operation of the refrigeration system 100, pressure fluctuations exist between the evaporator 3 and the reflux gas-liquid separator 5. For example, when the load on the compressor 1 changes or the opening of the throttle valve 4 is adjusted, the pressure inside the evaporator 3 may briefly increase. At this time, gaseous refrigerant may flow back into the reflux gas-liquid separator 5 due to the pressure difference. The check valve 6 only allows liquid refrigerant to flow from the reflux gas-liquid separator 5 to the evaporator 3, effectively blocking the reverse flow of gaseous refrigerant and fundamentally avoiding interference from the reverse airflow on the return path. Furthermore, the pressure difference between the reflux gas-liquid separator 5 and the evaporator 3 is one of the key factors driving the liquid refrigerant backflow. By preventing reverse airflow, the check valve 6 avoids interference from the pressure of the evaporator 3 on the pressure inside the reflux gas-liquid separator 5, maintaining the pressure inside the reflux gas-liquid separator 5 within a stable range conducive to gas-liquid separation.

[0067] It is understandable that the aforementioned check valve 6 can be selected according to the pressure parameters of the refrigeration system 100 and the type of refrigerant, such as a spring-loaded check valve or a gravity check valve.

[0068] In some embodiments, the reflux gas-liquid separator 5 is provided with a heat exchange tube 7, and the energy-saving direct expansion liquid supply refrigeration system 100 also includes a liquid receiver 8. The liquid receiver 8 is connected to the output port of the condenser 2 and is also connected to the heat exchange tube 7 of the reflux gas-liquid separator 5 to introduce refrigerant into the heat exchange tube 7 to heat the reflux gas-liquid separator 5.

[0069] Specifically, during the operation of the refrigeration system 100, especially in low-temperature refrigeration scenarios (e.g., 0℃ to -10℃), the separation chamber of the reflux gas-liquid separator 5 is in a low-temperature environment for a long time. If the temperature is too low, the refrigerant, especially some refrigerants that are easy to solidify or have increased viscosity at low temperatures, may freeze in the chamber, or adhere to the chamber wall, gas-liquid separation channel, and return port 51 due to increased viscosity, causing channel blockage or obstruction of return. At this time, the liquid refrigerant cannot flow back to the evaporator 3 smoothly, which not only undermines the operating basis of near-zero superheat throttling, but may also cause the liquid refrigerant to re-accumulate in the reflux gas-liquid separator 5, increasing the risk of liquid slugging in the compressor 1. At this time, the liquid receiver 8 stores the refrigerant condensed by the condenser 2, which has a certain amount of heat. By connecting the liquid receiver 8 to the heat exchange tube 7 of the reflux gas-liquid separator 5, the refrigerant flows into the heat exchange tube 7, and heat is exchanged using the temperature difference between the refrigerant and the separation chamber, thus heating the reflux gas-liquid separator 5. This heating method eliminates the need for additional heating devices such as electric heating wires. It directly utilizes the heat from the refrigerant already present in the refrigeration system 100, saving equipment costs and avoiding additional energy consumption. This ensures that the refrigerant in the reflux gas-liquid separator 5 always maintains good fluidity.

[0070] It is understandable that the heat exchange tube 7 can be made of a metal material with excellent thermal conductivity (such as copper or aluminum tubes), and the arrangement of the heat exchange tube 7 in the reflux gas-liquid separator 5 can be a spiral or serpentine structure surrounding the separation chamber.

[0071] In some embodiments, the energy-saving direct expansion refrigeration system 100 further includes a temperature sensor 9, which is disposed on the pipeline connecting the evaporator 3 and the reflux gas-liquid separator 5, and is used to detect the temperature of the refrigerant when it leaves the evaporator 3.

[0072] A temperature sensor 9 is installed on the pipeline connecting the evaporator 3 and the reflux gas-liquid separator 5. This sensor can monitor the temperature of the refrigerant as it leaves the evaporator 3 in real time, providing data support for the operation and control of the refrigeration system 100. By monitoring temperature changes, the control module 205 can promptly determine whether the heat exchange efficiency of the evaporator 3 and the refrigerant flow rate match the refrigeration demand, and assist in adjusting the operating power of the compressor 1 to better match the output of the compressor 1 with the actual refrigeration demand.

[0073] It is understandable that the temperature sensor 9 mentioned above can be selected according to the accuracy requirements of the refrigeration system, such as a thermocouple sensor or a platinum resistance sensor.

[0074] In some embodiments, the rated power of the refrigeration system 100 is greater than 50kW.

[0075] It is worth noting that large-scale refrigeration projects (such as large cold storage facilities, industrial ice-making workshops, and large-scale food processing cold chains) often require a continuous output of large amounts of cooling capacity. Direct expansion refrigerant supply systems without a reflux gas-liquid separator 5 suffer from excessively high energy consumption, making long-term operation prohibitively expensive. In contrast, this energy-efficient direct expansion refrigerant supply refrigeration system 100 can meet the high-load demands of large-scale refrigeration projects. Combined with the refrigeration system 100's zero or minimal superheat throttling and efficient liquid refrigerant reflux, its energy-saving advantages can be fully utilized in high-energy-consumption scenarios of large-scale refrigeration projects. This solves the problem of conventional direct expansion refrigerant supply systems being unsuitable for large-scale refrigeration projects due to excessive energy consumption, providing an energy-saving and economical solution for large-scale refrigeration projects and reducing long-term operating costs.

[0076] Please see Figure 5 This application also provides a tube ice machine 200, which uses the aforementioned refrigeration system 100.

[0077] In some embodiments, the ice maker is provided with an ice outlet 203, and the tube ice machine 200 also includes a de-icing pipe 202. One end of the de-icing pipe 202 is connected to the outlet of the liquid reservoir 8, and the other end of the de-icing pipe 202 is connected to the ice maker. The de-icing pipe 202 is used to transport the refrigerant in the liquid reservoir 8 to the ice maker during the de-icing stage, so that the ice strips produced by the ice maker can be separated from the ice maker and discharged from the ice outlet 203.

[0078] Specifically, the refrigeration system 100, equipped with an innovative structure including a reflux-type gas-liquid separator 5 and near-zero superheat throttling, provides efficient and stable cooling support for the ice-making process. The evaporator 3 of the refrigeration system 100 is integrated into the ice maker 201. When the refrigerant evaporates and absorbs heat in the evaporator 3, the surface temperature of the ice maker 201 rapidly drops below zero degrees Celsius. Cold water continuously flows over the surface of the ice maker 201 and gradually condenses into tubular ice strips. Because the refrigeration system 100 uses zero superheat throttling or minimal superheat throttling, the evaporator 3 can obtain a refrigerant circulation volume exceeding one time (more than double the circulation volume), significantly increasing the heat exchange efficiency between the refrigerant and the ice maker 201. This results in faster cooling of the ice maker 201, shorter ice strip condensation time, directly accelerating ice-making speed and increasing ice production per unit time.

[0079] Furthermore, the liquid refrigerant reflux function of the reflux-type gas-liquid separator 5 ensures the stability of the refrigeration cycle. The separated liquid refrigerant returns to the evaporator 3 in a timely manner to participate in heat absorption, avoiding refrigeration fluctuations caused by the accumulation of liquid refrigerant, and keeping the temperature of the ice maker 201 uniform and stable at all times.

[0080] In the ice-making cycle of the tube ice machine 200, after ice making is completed, a de-icing stage is required to remove the ice strips from the ice machine. Existing de-icing methods often require additional heating devices (such as electric heating elements), which not only increases equipment costs but also consumes additional energy. In this embodiment, the de-icing pipeline 202 of the tube ice machine 200 utilizes the liquid refrigerant stored in the refrigeration system 100. This refrigerant is transported to the ice machine through the de-icing pipeline 202, and the heat from the refrigerant raises the temperature of the ice machine, reducing the freezing adhesion between the ice strips and the pipe wall, allowing the ice strips to detach smoothly and exit from the ice outlet 203. Thus, there is no need to add a dedicated de-icing heating device; the de-icing function can be completed directly using the refrigerant in the refrigeration system 100. Simultaneously, the refrigerant supply in the liquid reservoir 8 is stable, and the heat delivered to the ice machine through the de-icing pipeline 202 is uniform and controllable. This avoids localized overheating that could cause the ice strips to melt or damage the pipe wall, ensuring a gentle and efficient de-icing process, reducing the generation of broken ice, and ultimately improving the product qualification rate.

[0081] In some embodiments, a control valve 204 is provided on the de-icing line 202, and the tube ice machine 200 also includes a control module 205. The control module 205 is electrically connected to the throttle valve 4 and the control valve 204. The control module 205 is configured to control the throttle valve 4 to close during the de-icing stage and to control the control valve 204 to open so that the refrigerant in the liquid receiver 8 can be delivered to the ice maker.

[0082] Specifically, the ice-making stage requires the refrigeration system 100 to continuously provide cooling to cool the ice maker and freeze it, while the de-icing stage requires heat to detach the ice strips from the pipe wall. In other words, if the refrigeration function and the de-icing function are running at the same time, the refrigerant is cooling in the evaporator 3, while the de-icing pipe 202 is also transferring heat to the evaporator 3. This not only wastes energy but also causes abnormal temperature fluctuations in the ice maker 201, thus affecting the de-icing effect.

[0083] Furthermore, in the de-icing stage of this embodiment, the control module 205 first closes the throttle valve 4, cutting off the refrigerant passage to the liquid receiver 8, so that the refrigeration function of the refrigeration system 100 stops operating. At the same time, the control module 205 opens the valve of the control valve 204 of the de-icing pipeline 202, so that the refrigerant in the liquid receiver 8 flows into the ice maker 201. The heat it carries is concentrated on the pipe wall, causing the temperature to rise steadily, and successfully allowing the ice strip to slide out from the ice outlet 203.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An energy-saving direct expansion liquid supply refrigeration system, characterized in that, include: compressor; A condenser, wherein the condenser piping is connected to the compressor; An evaporator, wherein the evaporator piping is connected to the condenser; A throttling valve is installed on the pipeline connecting the evaporator and the condenser; A reflux gas-liquid separator is provided, wherein the reflux gas-liquid separator pipe is connected between the evaporator and the compressor. The reflux gas-liquid separator is used to separate the gas-liquid mixture of refrigerant discharged from the evaporator, so as to deliver the separated gaseous refrigerant to the compressor. The reflux gas-liquid separator is provided with a reflux port, and the reflux port pipe is connected to the evaporator, so as to return the liquid refrigerant in the reflux gas-liquid separator to the evaporator, so that the opening degree of the throttle valve is adjusted independently of the superheat of the refrigerant at the evaporator outlet.

2. The energy efficient direct expansion liquid supplied refrigeration system of claim 1, wherein, The reflux port is located at the bottom of the reflux gas-liquid separator. The top of the reflux gas-liquid separator is provided with a liquid inlet and a gas outlet. The liquid inlet pipe is connected to the evaporator so that the gas-liquid mixed refrigerant discharged from the evaporator enters the separation chamber for gas-liquid separation. The gas outlet pipe is connected to the compressor so as to deliver the separated gaseous refrigerant to the compressor.

3. The energy efficient direct expansion liquid supplied refrigeration system of claim 2, wherein, The reflux gas-liquid separator is installed at a height higher than the evaporator in the vertical direction, so that the reflux port is located above the evaporator in the vertical direction, so as to return the liquid refrigerant to the evaporator.

4. The energy efficient direct expansion liquid supplied refrigeration system of claim 2, wherein, A check valve is provided on the pipeline connecting the return port to the evaporator. The check valve is used to prevent the gaseous refrigerant in the evaporator from flowing back into the reflux gas-liquid separator.

5. An energy efficient direct expansion liquid supplied refrigeration system as claimed in any one of claims 1 to 4, wherein, The reflux gas-liquid separator is equipped with heat exchange tubes; The energy-saving direct expansion liquid supply refrigeration system also includes a liquid receiver, the liquid receiver pipe is connected to the output port of the condenser, and the liquid receiver pipe is also connected to the heat exchange tube of the reflux gas-liquid separator to introduce refrigerant into the heat exchange tube to heat the reflux gas-liquid separator.

6. An energy efficient direct expansion liquid supplied refrigeration system as claimed in any one of claims 1 to 4, wherein, The energy-saving direct expansion liquid supply refrigeration system also includes a temperature sensor, which is installed on the pipeline connecting the evaporator and the reflux gas-liquid separator. The temperature sensor is used to detect the temperature of the refrigerant when it leaves the evaporator.

7. An energy efficient direct expansion liquid supplied refrigeration system as claimed in any one of claims 1 to 4, wherein, The rated power of the refrigeration system is greater than 50kW.

8. A tube ice machine, characterized in that, The tube ice machine includes an ice maker and an energy-saving direct expansion liquid supply refrigeration system as described in any one of claims 1-7, wherein the evaporator of the refrigeration system is disposed in the ice maker.

9. The tube icemaker of claim 8 wherein, The ice maker is provided with an ice outlet, and the tube ice maker also includes an ice removal pipeline. One end of the ice removal pipeline is connected to the outlet of the liquid reservoir, and the other end of the ice removal pipeline is connected to the ice maker. The ice removal pipeline is used to transport the refrigerant in the liquid reservoir to the ice maker during the ice removal stage, so that the ice strips produced by the ice maker can be separated from the ice maker and discharged from the ice outlet.

10. The tube icemaker of claim 9 wherein, The de-icing pipeline is equipped with a control valve, and the tube ice machine also includes a control module. The control module is electrically connected to the throttle valve and the control valve. The control module is configured to control the throttle valve to close during the de-icing stage and to control the control valve to open so that the refrigerant in the liquid receiver can be delivered to the ice maker.

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