A flooded heat-pipe type high-efficiency evaporator

Abstract

The application provides a full-liquid heat recovery type high-efficiency evaporator, which can solve the problem of complete evaporation of incompletely evaporated refrigerant, improve the suction gas superheat degree of a compressor by using twice heat exchange, completely solve the suction liquid carrying phenomenon, ensure the pure oil state lubrication of the rotor in the compressor, reduce the oil separation and oil return amount, and eliminate the heat loss caused by the liquid carrying and oil running of the compressor. The evaporator comprises a shell, a partition plate and heat exchange pipes, the bottom of the shell is provided with an inlet pipe, the top of the shell is provided with an outlet pipe, the left and right ends of the shell are respectively divided into a plurality of internal areas by the partition plate, the internal areas at the left and right ends of the shell are communicated through the heat exchange pipes, the end of the shell is further provided with a water inlet pipe and a water outlet pipe for supplying water to the heat exchange pipes, a heat recovery heat exchange fin assembly for heating the rising gas mist and flying liquid is arranged at the internal area of the shell close to the outlet pipe, and the gas mist and flying liquid are converted into a pure gas state after being heated by the heat recovery heat exchange fin assembly.

Description

Technical Field

[0001] This invention relates to the field of evaporator technology, and in particular to a flooded regenerative high-efficiency evaporator. Background Technology

[0002] Currently, for flooded chiller refrigeration systems, according to Chinese standards JB / T3355-1998 and GB / T18403.1-2001, the chilled water flow rate on the evaporator side (chilled water inlet and outlet temperatures of 12 / 7℃, and cooling water inlet and outlet temperatures on the condenser side of 30 / 35℃) is determined based on the unit's cooling capacity. The refrigerant evaporation temperature is controlled at 3-5℃, and the evaporation temperature is lower than the chilled water outlet temperature (2-4℃) to ensure an outlet water temperature of 7℃. The chilled water supply and return temperatures are 12℃. In a refrigeration system, after the screw compressor starts drawing in refrigerant, evaporation begins in the refrigerant evaporator. During this high-level evaporation and boiling process, a large amount of wet vapor containing fine liquid mist and splashing droplets is generated. This mist and droplets are carried by the airflow through the small holes in the baffle plate and along the direction of the gas flow, drawing liquid into the compressor. Simultaneously, the liquid entering the compressor dilutes and mixes with the lubricating oil, causing the oil level to rise. This leads to oil leakage due to liquid in the compressor, increasing mechanical wear and heat generation, and negatively impacting the lifespan of the rotor bearings. After the oil-liquid mixture enters the oil-gas separator with the compressor discharge, a large amount of lubricating oil is separated. At this point, oil return is achieved using the high-pressure difference between the compressor's high and low pressures. The high-pressure discharge forces the separated lubricating oil back into the compressor for recirculation. Therefore, the hot lubricating oil brought back to the compressor causes additional heat loss and poses a significant risk of liquid slugging. Therefore, when the superheat value (K) fed back by the superheat sensor decreases, the opening of the electronic expansion valve is adjusted to lower the liquid level, ensuring that dry vapor is drawn into the compressor to prevent liquid slugging. Simultaneously, the expansion valve is controlled to close slightly, reducing the liquid supply and causing the heat exchange tubes to rise above the liquid level to increase superheat. This also reduces the heat exchange area, and the heat exchange tubes are not fully immersed in the refrigerant, resulting in inefficient heat exchange. Therefore, optimizing the evaporator structure and improving operating efficiency, to ensure efficient heat exchange and raise the liquid level, requires completely immersing the heat exchange tubes in the refrigerant to minimize heat exchange losses. Furthermore, it is necessary to completely evaporate the liquid mist and splashed droplets into a pure gaseous state, thereby extending the compressor bearing life and achieving efficient evaporation to improve heat exchange efficiency. This has become a core research direction urgently needed. Summary of the Invention

[0003] To overcome the above deficiencies, this invention provides a flooded regenerative high-efficiency evaporator. This type of evaporator can solve the problem of fully evaporating incompletely evaporated refrigerant. It uses two heat exchanges to improve the superheat of the compressor suction, completely solves the problem of liquid carryover in the suction, ensures pure oil lubrication of the compressor rotor, reduces the amount of oil separation and return, and eliminates heat loss due to liquid carryover and oil runoff in the compressor.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A full-fill regenerative high-efficiency evaporator includes a shell, partition plates, and heat exchange tubes. A liquid inlet pipe is provided at the bottom of the shell, and an air outlet pipe is provided at the top. The left and right ends of the shell are divided into several internal regions by partition plates. The internal regions at the left and right ends of the shell are connected by heat exchange tubes. A water inlet pipe and a water outlet pipe for supplying water to the heat exchange tubes are also provided at the ends of the shell. A regenerative heat exchange fin assembly is provided inside the shell near the air outlet pipe to heat up the rising mist and liquid. After being heated by the regenerative heat exchange fin assembly, the mist and liquid are transformed from a mist and liquid state into a pure gaseous state.

[0005] Compared with existing technologies, this technical solution has the following technical advantages: In this application, a heat exchange component is installed at the outlet pipe of the evaporator to raise the temperature of the gas mist and liquid, transforming them from a gas mist and liquid state into a pure gas state. This prevents liquid droplets in the gas mist from being drawn into the compressor, ensuring the temperature of the regenerated gas in the compressor. It also eliminates the situation where the refrigerant and lubricating oil mix and dilute, causing the compressor oil level to rise, increasing mechanical wear and heat generation, and resulting in liquid leakage and oil spillage, which would lead to an excessively high compression ratio and increased compressor energy consumption.

[0006] As a further description of the above technical solution: the heat exchange assembly includes a baffle, a frame, and several regenerative branch pipes fixed on the frame, which are arranged laterally inside the shell. The baffle is arranged laterally inside the shell, and one and both ends of the baffle are fixedly connected to and sealed to the inside of the shell. The frame is fixed on the other end of the baffle, and the regenerative branch pipes are respectively mounted on the frame. There are gaps between each regenerative branch pipe for the aerosol and liquid to pass through. In this way, the structure is simple. Due to the presence of the baffle, the aerosol can only enter the outlet pipe through the gaps between the regenerative branch pipes. Therefore, the heating through the regenerative branch pipes can evaporate the aerosol and liquid, causing them to vaporize.

[0007] As a further description of the above technical solution: fins are fixed on the outside of the regenerating branch pipe, which can increase the contact area between the regenerating branch pipe and the aerosol and liquid, thereby improving the heat exchange efficiency.

[0008] As a further description of the above technical solution: the regenerating branch pipe, fins and heat exchange tubes are all made of metal materials.

[0009] As a further description of the above technical solution: an air intake baffle is also provided on the top of the baffle.

[0010] As a further description of the above technical solution: the water flowing into the inlet pipe is split into the heat exchange tube and the regenerating branch pipe in the internal area of ​​one end of the shell. The water in the regenerating branch pipe flows into the internal area of ​​the other end of the shell from the outlet and mixes with the water in the heat exchange tube, and finally flows out from the outlet pipe. In this way, the relatively high temperature water in the inlet pipe can be used directly to evaporate the mist and droplets, further improving the heat utilization rate. Moreover, the structure is simple and does not require major modifications to the existing evaporator structure, making it highly practical.

[0011] As a further description of the above technical solution: the ends of adjacent regenerative branch pipes are connected, and after merging, they are connected to the internal areas at both ends of the shell.

[0012] As a further description of the above technical solution: Inside the shell, a baffle plate is horizontally arranged below the heat exchange fin assembly. This can shield the boiling refrigerant and reduce the entry of splashing droplets. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of a flooded regenerative high-efficiency evaporator according to the present invention; Figure 2 This is a side view of a flooded regenerative high-efficiency evaporator according to the present invention; Figure 3 This is a left view of a flooded regenerative high-efficiency evaporator according to the present invention; Figure 4 This is a right view of a flooded regenerative high-efficiency evaporator according to the present invention; Figure 5 This is a schematic diagram showing the flow direction of water in the inlet pipe in this invention; Figure 6 This is a schematic diagram illustrating another installation method for the regenerative heat exchange fin assembly in this invention. Legend: 1. Shell; 2. Divider plate; 3. Heat exchange tube; 4. Liquid inlet pipe; 5. Gas outlet pipe; 6. Internal area; 7. Water inlet pipe; 8. Water outlet pipe; 9. Baffle; 10. Frame; 11. Regenerating branch pipe; 12. Suction baffle; 13. Liquid baffle. Detailed Implementation

[0014] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] Reference Figures 1-4 One embodiment provided by the present invention: A full-fill regenerative high-efficiency evaporator includes a shell 1, a partition plate 2, and a heat exchange tube 3. The bottom of the shell 1 is provided with a liquid inlet pipe 4, and the top is provided with a gas outlet pipe 5. The left and right ends of the shell 1 are respectively divided into several internal regions 6 by the partition plate 2. The internal regions 6 at the left and right ends of the shell 1 are connected by the heat exchange tube 3. At the end of the shell 1, a water inlet pipe 7 and a water outlet pipe 8 are provided for supplying water to the heat exchange tube 3. Inside the shell 1, near the gas outlet pipe 5, a regenerative heat exchange fin assembly is provided to heat up the rising mist and liquid. After being heated by the regenerative heat exchange fin assembly, the mist and liquid are transformed from mist and liquid into pure gas. In this application, a heat exchange component is installed at the outlet pipe 5 of the evaporator to raise the temperature of the gas mist and liquid, so that it is transformed from a gas mist and liquid state into a pure gas state. This prevents the liquid droplets in the gas mist from being drawn into the compressor, ensuring the temperature of the regenerated gas in the compressor. It also eliminates the problem of the compressor oil level rising due to the mixing and dilution of refrigerant and lubricating oil, which increases mechanical wear and heat generation, and causes liquid leakage, resulting in an excessively high compression ratio and increased compressor energy consumption.

[0016] In this embodiment, the heat exchange assembly includes a baffle 9, a frame 10, and several regenerative branch pipes 11 fixed on the frame 10, all arranged laterally inside the housing 1. The baffle 9 is arranged laterally inside the housing 1, with one and both ends of the baffle 9 fixedly connected to and sealed to the interior of the housing 1. The frame 10 is fixed to the other end of the baffle 9, and the regenerative branch pipes 11 are respectively mounted on the frame 10. There are gaps between each regenerative branch pipe 11 for the passage of aerosol and liquid. This structure is simple. Due to the presence of the baffle 9, the aerosol can only enter the outlet pipe 5 through the gaps between the regenerative branch pipes 11. Therefore, the regenerative branch pipes 11 can be used to heat up the aerosol and liquid, thereby evaporating them and causing them to vaporize.

[0017] In this embodiment, fins are fixed to the outside of the regenerating branch pipe 11, which can increase the contact area between the regenerating branch pipe 11 and the aerosol and liquid, thereby improving the heat exchange efficiency.

[0018] In this embodiment, the regenerating branch pipe 11, the fins, and the heat exchange tube 3 are all made of metal materials.

[0019] In this embodiment, an air intake baffle 12 is also provided on the top of the baffle 9.

[0020] In this embodiment: the water flowing into the inlet pipe 7 is split into the heat exchange pipe 3 and the regenerating branch pipe 11 after entering the internal region 6 at one end of the shell 1. The water in the regenerating branch pipe 11 flows from the outlet into the internal region 6 at the other end of the shell 1 and mixes with the water in the heat exchange pipe 3 to enter the second pass. Finally, after passing through the third and fourth passes, it flows out from the outlet pipe 8. The second, third, and fourth passes are the internal regions at both ends of the shell 1. In this way, the relatively high temperature water in the inlet pipe 7 can be used directly to evaporate the mist and droplets, further improving the heat utilization rate. Moreover, the structure is simple and does not require major modifications to the existing evaporator structure, making it highly practical.

[0021] In this embodiment: the ends of adjacent heat recovery branch pipes 11 are connected and merged to communicate with the internal regions 6 at both ends of the shell 1 respectively. The heat recovery branch pipes 11 are fixed through the mounting holes on the frame 10.

[0022] In this embodiment, a baffle plate 13 is horizontally arranged inside the housing 1 below the heat exchange fin assembly. This can shield the boiling refrigerant and reduce the entry of splashing droplets.

[0023] This embodiment illustrates a structure employing four sets of heat exchange tubes, which can be referenced. Figure 5 The heat exchange tubes 3 are arranged in four groups, arranged in pairs, one above the other. The partition plates include left and right end plates for fixing the left and right ends of the heat exchange tubes, and left and right partition plates for separating the left and right end plates from the shell. Each left and right end plate has mounting holes for the heat exchange tubes 3, and these holes are sealed to the heat exchange tubes. The edges of the left and right end plates are sealed to the interior of the shell 1. The right partition plate includes a horizontal plate and a vertical plate. The horizontal plate divides the right end of the shell into upper and lower internal areas, and the vertical plate... The upper internal region of the right end of the shell is divided into two internal regions, left and right. Each of the two internal regions is connected to a set of heat exchange tubes. Two sets of heat exchange tubes 3 are arranged side by side in the lower internal region. The left partition is vertically arranged to divide the left end of the shell into two internal regions. The inlet of the heat recovery branch pipe 11, the inlet of the heat exchange tube 3 and the inlet pipe 4 are located in one internal region 6. The outlet of the heat recovery branch pipe 11 is connected to the upper left internal region 6 of the right end of the shell. High-efficiency heat exchange is achieved through four sets of heat exchange tubes 3 to ensure the efficiency of the evaporator.

[0024] In this embodiment, a vertically arranged regenerative heat exchange fin assembly can also be used, as detailed in the following figure. Figure 6 .

[0025] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A flooded regenerative high-efficiency evaporator, comprising a shell, partition plates, and heat exchange tubes, wherein a liquid inlet pipe is provided at the bottom of the shell, and a gas outlet pipe is provided at the top; the left and right ends of the shell are respectively divided into several internal regions by partition plates, and the internal regions at the left and right ends of the shell are connected by heat exchange tubes; and a water inlet pipe and a water outlet pipe for supplying water to the heat exchange tubes are also provided at the ends of the shell, characterized in that... Inside the shell, near the air outlet, there is a heat exchange fin assembly that can heat up the rising mist and liquid. After being heated by the heat exchange fin assembly, the mist and liquid are transformed from mist and liquid into pure gas.

2. The flooded regenerative high-efficiency evaporator according to claim 1, characterized in that: The heat exchange assembly includes a baffle, a frame, and several regenerative branch pipes fixed on the frame, which are arranged horizontally inside the shell. The baffle is arranged horizontally inside the shell, and one end and both ends of the baffle are fixedly connected to the inside of the shell and sealed. The frame is fixed on the other end of the baffle. The regenerative branch pipes are respectively mounted on the frame, and there are gaps between each regenerative branch pipe for the passage of aerosol and liquid.

3. The flooded regenerative high-efficiency evaporator according to claim 2, characterized in that: The regenerative branch pipe is fixed with fins on the outside.

4. The flooded regenerative high-efficiency evaporator according to claim 3, characterized in that: The regenerating branch pipe, fins, and heat exchange tubes are all made of metal.

5. A flooded regenerative high-efficiency evaporator according to claim 2, characterized in that: An air intake baffle is also provided on the top of the baffle.

6. A flooded regenerative high-efficiency evaporator according to claim 2, characterized in that: The water flowing into the inlet pipe is then split into the heat exchange tube and the regenerating branch pipe in the internal area of ​​one end of the shell. The water in the regenerating branch pipe flows from the outlet into the internal area of ​​the other end of the shell and mixes with the water in the heat exchange tube, and finally flows out from the outlet pipe.

7. A flooded regenerative high-efficiency evaporator according to claim 2, characterized in that: The adjacent regenerative branch pipes are connected end to end, and after merging, they are connected to the internal regions at both ends of the shell.

8. A flooded regenerative high-efficiency evaporator according to claim 2, characterized in that: Inside the housing, a baffle plate is horizontally arranged below the heat exchange fin assembly.

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