Stepped natural convection condenser

Abstract

The present invention provides a stepped natural convection condenser. [Solution] The condenser includes a stepped heat collecting tube, a stepped steam tube, a water collecting bend, a condensed water collecting chamber and a heat insulating housing, the steam tube is arranged coaxially and telescoped outside the heat collecting tube, the tube diameter meets a specific formula, cold water and steam flow through the heat absorbing tube and the steam tube respectively, forming a torsional perfect natural convection heat transfer inside and outside the tube, the telescope pipes are connected in series in a stepped staggered manner for each layer and arranged on an inclined flat plate with a specific gradient, the gradient and cold water flow rate meet a specific formula, the stepped telescope pipes are connected every two layers using a removable telescope type U-shaped tube and a water collecting bend, the cross-sectional shape of the water collecting bend meets an ellipse equation, a gas valve is provided at the outlet of the condensed water collecting chamber, and the stepped telescope pipe and the condensed water collecting chamber are arranged in a heat insulating housing. The unique concept of the present invention allows the cold source to be fully natural convection, reduces energy consumption, lowers thermal resistance, improves the utilization rate of thermal energy and the efficiency of heat exchange, saves site space, and is applicable to both high pressure and negative pressure conditions.

Description

[Technical field]

[0001] The present invention relates to the field of condensers, and in particular to a stepped self-convection condenser. [Background technology]

[0002] In power systems and refrigeration systems, the condenser is one of the main equipments, whose function is to exchange heat between hot and cold sources, to realize energy recycling, or to cool polluting heat sources and then discharge them again, thereby reducing pollution to the environment.

[0003] According to the contact method, condensers are mainly divided into hybrid condensers and bulkhead condensers, among which bulkhead condensers are used when two fluids cannot or are not expected to come into direct contact with each other, and have a wider range of applications. There are various types of bulkhead condensers, including plate type, shell and tube type, and ferrule type. Among them, the shell-and-tube heat exchanger has problems such as short contact time of the cold and hot sources, limited temperature difference of the cold and hot sources, and low heat exchange efficiency. The ferrule heat exchanger needs to be driven by pump force to move the hot and cold fluids, and cannot realize natural flow and natural convection. The condensate cannot be quickly collected at the bottom layer, and the condensate adheres to the tube wall, resulting in high heat exchange resistance. The pipes are connected by fixed U-shaped tubes, which makes maintenance difficult. There is no external housing protection, and heat dissipation to the external environment cannot be avoided. The external environment has a large impact, and the outer tube is easily worn and damaged. The ratio of the inner tube diameter to the outer tube diameter and the ratio of the flow rate and flow rate are not clearly set, resulting in high consumption of cold fluid, low heat exchange efficiency and low utilization rate of heat energy, etc. Summary of the Invention [Problem to be solved by the invention]

[0004] In response to the shortcomings of the prior art, the present invention provides a stepped natural convection condenser to solve problems such as a short contact time of the cold heat source, difficulty in forming natural flow convection, increased heat exchange resistance due to adhesion of condensate, low heat exchange rate, and insufficient energy recovery and utilization. [Means for solving the problem]

[0005] In order to achieve the above object, the present invention is realized by the following technical solutions.

[0006] A stepped natural convection condenser, the stepped natural convection condenser comprising a stepped heat collecting tube, a stepped steam tube, a water collecting bend, a condensate collecting chamber and a thermally insulated housing; The stepped heat collecting tube and the stepped steam pipe are coaxial and in a telescopic form to form a stepped telescopic pipe, and the pipe diameter of the stepped heat collecting tube is smaller than the pipe diameter of the stepped steam pipe, The telescope pipes are connected in series in a staggered stepped manner for each layer, and are arranged on an inclined flat plate with a predetermined gradient J. Between two stepped telescope pipes in each layer, a telescope-type U-shaped pipe is connected, and between two stepped telescope pipes in each layer, a telescope-type U-shaped pipe and a water-collecting bend are connected, and the shape of the water-collecting bend is as follows: Satisfying the elliptical rotational body equation of TIFF2025511619000002.tif1973, Here, x, y, and z indicate the three directions that constitute the spatial coordinate system, and the direction setting satisfies the right-hand rule of the Cartesian coordinate system. The condensate collecting chamber is connected to a water collecting bend and is provided with a gas valve and a drain. The condensate collecting chamber and the stepped telescopic pipe are disposed within the thermally insulated housing. The condensate collecting chamber is located within the housing near the bottom, and the stepped telescopic pipe is located above the condensate collecting chamber. The heat collecting pipe diameter d i and steam pipe diameter d v teeth The equation in TIFF2025511619000003.tif1830 is satisfied, and the heat transfer ratio is TIFF2025511619000004.tif1721, hl , h v indicate the heat transfer coefficients of cold water and steam, respectively. Cold water naturally flows from top to bottom within the stepped heat collection tube, and steam naturally flows from bottom to top between the stepped heat collection tube and the stepped steam tube, forming twisted perfect natural convection heat transfer inside and outside.

[0007] Furthermore, a steam passage is formed between the stepped steam pipe and the stepped heat collecting tube, and the steam naturally flows from the lower inlet of the housing from bottom to top along the steam passage, and the steam and the cold water in the heat collecting tube have a mass flow ratio k m Heat transfer by twisted natural convection occurs according to the mass flow ratio k m teeth TIFF2025511619000005.tif1937, where c l is the cold water specific heat capacity, and r v is the latent heat of vapor, TIFF2025511619000006.tif89 is the cold water heat exchange temperature difference, The condensed water flows from top to bottom along the steam passage through a water collecting bend into the condensed water collecting chamber at the bottom of the housing, where the water collecting bend, whose cross-sectional shape satisfies an elliptical equation, allows the condensed water in the steam passage at the upper layer to be quickly collected in the lower layer.

[0008] Furthermore, the diameter of the stepped heat collecting tube is smaller than the diameter of the stepped steam tube, and the cold water flows from the upper inlet of the housing from top to bottom along the stepped heat collecting tube, and the flow rate ratio is According to TIFF2025511619000007.tif96, natural convection heat exchange is performed with the steam outside the heat collector tube, and the flow rate ratio is TIFF2025511619000008.tif96 TIFF2025511619000009.tif2351, Here, the density ratio is TIFF2025511619000010.tif1724, and ρ v , ρ l is the density of the steam and cold water.

[0009] Furthermore, the stepped telescopic pipes are connected in series in a staggered manner for each layer, and placed on an inclined flat plate with a predetermined gradient J, where J is 2% to 3%. Between the telescopic pipes of each layer, a telescopic U-tube is used to connect in series with a gradient J in the horizontal direction, and one flow rate control valve is provided in the telescopic pipe of each layer. The flow rate of the cold water in the heat collecting tube is expressed by the following formula 1:

number

[0010] In addition, the condensate collecting chamber is located at the bottom of the housing, connected to the bottom water collecting bent pipe, and collects the condensate in the stepped telescopic pipe. The bottom of the collecting chamber is provided with a drain and a gas valve. The gas valve is attached to the drain. When the condenser is working, the gas valve is in a closed state, and the condensate is stored in the collecting chamber, maintaining an operating environment higher or lower than the normal pressure set in the condenser. When the condenser is completely stopped, the gas valve is opened to adjust the pressure in the condenser to normal pressure, and the condensate is discharged from the condenser.

[0011] Specifically, the insulating housing is a horizontal cylindrical shape. Effect of the Invention

[0012] According to the above technical solutions, the present invention has the following beneficial effects:

[0013] This device, under the premise of having good protection and insulation for the internal pipe, uses a unique pipe design to make the cold source fully natural convection, reducing energy consumption and saving energy; processes according to the set pipe diameter ratio and flow rate-gradient relationship, allows the cold source to obtain sufficient contact time and heat transfer area, achieves the desired heat exchange amount, effectively realizes the exchange of heat energy, saves the use of cold source, improves the utilization rate of heat energy and heat exchange efficiency; designs the bent water collection pipe to quickly collect condensed water at the bottom layer and reduce thermal resistance; closes the gas valve when the condenser is working, and opens the gas valve when it is stopped, effectively maintaining the internal pressure; and is applicable to both high pressure and negative pressure, that is, the operating pressure range is increased, and the steam and water droplets remaining in the device are automatically removed; and is arranged in a hierarchical telescope, significantly reducing the occupied area. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a side view of a stepped natural convection condenser according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a side view of a stepped telescope pipe according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a plan view of a stepped telescope pipe according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The drawings constituting a part of the present invention are intended to provide a further understanding of the present invention, and the schematic embodiments of the present invention and the description thereof are intended to interpret the present invention and are not intended to unduly limit the present invention.

[0016] In addition, unless contradictory, the embodiments and features of the embodiments in the present application can be combined with each other. Hereinafter, the present invention will be described in detail with reference to the embodiments with reference to the drawings.

[0017] 1 to 3, an embodiment of the present invention provides a stepped natural convection condenser, which includes a stepped heat collecting tube 1, a stepped steam tube 2, a water collecting bend 3, a condensate collecting chamber 4, and a heat insulating housing 5, the diameter of the stepped heat collecting tube 1 is smaller than the diameter of the stepped steam tube 2, and the two tubes are coaxially in a telescopic form to form a stepped telescope pipe 6, and the diameter d of the heat collecting tube 1 is smaller than the diameter of the stepped steam tube 2, and the two tubes are coaxially in a telescope form to form a stepped telescope pipe 6, and the diameter d of the heat collecting tube 1 is smaller than the diameter of the stepped steam tube 2, the diameter d of the stepped steam tube 2 is smaller than the diameter of the stepped steam tube 2, and the stepped telescope pipe 6 is formed by the stepped steam tube 2, ... l and the diameter of steam pipe 2, d v teeth, TIFF2025511619000012.tif1830, where the heat transfer ratio is, TIFF2025511619000013.tif1721, h l , h v and denote the heat transfer coefficients between cold water and steam, respectively.

[0018] Cold water flows naturally from top to bottom in the stepped heat collecting tube 1, and steam flows naturally from bottom to top between the stepped heat collecting tube 1 and the stepped steam tube 2, forming a twisted perfect natural convection heat transfer inside and outside. The telescope pipes are connected in series in a stepped staggered manner for each layer and arranged on an inclined flat plate 8 with a predetermined gradient J. A telescope U-shaped tube is connected between two stepped telescope pipes in each layer, and a removable telescope U-shaped tube 7 and a water collecting bend 3 are connected between two stepped telescope pipes 6 in each layer. The shape of the water collecting bend 3 is expressed by an ellipsoidal revolution equation. TIFF2025511619000014.tif1872, where x, y, and z indicate three directions and constitute a spatial coordinate system, and the direction settings satisfy the right-hand rule of the Cartesian coordinate system.

[0019] The condensate collecting chamber 4 is connected to a water collecting bend 3 and is provided with a gas valve and a drain. The condensate collecting chamber 4 and the stepped telescopic pipe 6 are disposed within the thermally insulated housing 5. The condensate collecting chamber 4 is located within the thermally insulated housing 5 near the bottom, and the stepped telescopic pipe 6 is located above the condensate collecting chamber 4.

[0020] In addition, the complete natural convection heat exchange between steam and cold water can reduce energy consumption. The design of the hierarchical telescope stepped telescope pipe 6 can effectively reduce the site area under the premise of improving the heat exchange efficiency. The water collecting bend 3 is designed and processed according to the above geometric equation, which does not increase the processing difficulty and effectively prevents the condensed water from adhering to the pipe wall when it flows through the bend, so that the condensed water of each layer can be quickly collected. The relationship equation between the pipe diameters and the geometric equation of the water collecting bend 3 are both for improving the heat exchange efficiency and improving the heat exchange effect. In actual application, certain adjustments can be made according to the processing situation and heat exchange conditions.

[0021] In this embodiment, a steam passage is formed between the stepped steam pipe 2 and the stepped heat collecting pipe 1, and steam naturally flows from the lower end inlet of the heat insulating housing 5 from bottom to top along the steam passage, According to the flow rate ratio of TIFF2025511619000015.tif1937, heat transfer occurs through twisted natural convection with the cold water in the heat collection tube 1, causing a phase change and generating condensate. The condensate flows from top to bottom along the steam passage through the bent water collection tube 3 into the condensate collection chamber 4, and the cold water flows from the top inlet of the insulating housing 5 from top to bottom along the stepped heat collection tube 1. Natural convection heat exchange is performed with the steam outside the heat collection tube 1 according to the flow rate ratio of TIFF2025511619000016.tif2351, among which the density ratio is The file is TIFF2025511619000017.tif1624.

[0022] In addition, c in the above formula l is the cold water specific heat capacity, and r v is the latent heat of steam, ρ is the density of the steam and cold water, TIFF2025511619000018.tif79 is the heat exchange temperature difference of cold water. The water collecting bend 3 designed between every two layers can make the condensate in the steam pipeline 2 of each layer quickly collect in the bottom layer and finally merge into the condensate collecting chamber 4, effectively reducing the flow resistance and thermal resistance of each layer, improving the heat exchange effect, and improving the heat exchange efficiency.

[0023] In this embodiment, the stepped telescopic pipes 6 are connected in series in a staggered manner in each layer, and are arranged on an inclined flat plate 8 with a predetermined gradient J, where J is generally 2% to 3%. Between the telescopic pipes 6 in each layer, a telescopic U-tube 7 is used to connect in series with a gradient J in the horizontal direction. A flow rate control valve is provided in the telescopic pipes in each layer, and the flow rate of the cold water in the heat collecting tube 1 satisfies the following formula 1:

number

[0024] Furthermore, by using the flow rate control valve to control the flow rate of the cold water according to the flow rate limiting formula, it is possible to process a sufficient amount of steam without the need to consume excessive cold water, reduce the amount of cold water used, effectively guarantee the operating speed and heat exchange efficiency, and play a role in saving energy. This device uses an inclined flat plate 8 to support the stepped telescopic pipe 6, which aims to stabilize the pipe, reduce the increase in pipe vibration and thermal stress caused by flow rate or temperature difference, increase the application range of the pipe, and play a good protective role for the pipe.

[0025] In this embodiment, the telescopic U-tube 7 connected to the stepped telescopic pipeline 6 of each layer is a normal fixed port telescopic U-tube 7, which can ensure the sealing between each tube in each layer. The telescopic U-tube 7 of the stepped telescopic pipeline 6 every two layers is connected in series vertically using a flange, which is a removable port, and the port is provided with a gasket to avoid the problem of liquid leakage from the port. The purpose of providing a removable telescopic U-tube 7 between every two layers is to facilitate later maintenance and inspection of the device.

[0026] In this embodiment, the condensate collecting chamber 4 is located at the bottom of the heat-insulating housing 5, connected to the bottom water collecting bend 3, and collects the condensate in the stepped telescopic pipe 6. The bottom of the collecting chamber 4 is provided with a drain and a gas valve. The gas valve is attached to the drain. When the condenser is working, the gas valve is closed, and the condensate is stored in the collecting chamber 4, maintaining the working environment set in the condenser at a pressure higher than or lower than the normal pressure. When the condenser is completely stopped working, the gas valve is opened, and the pressure in the condenser is adjusted to normal pressure, and the condensate is discharged from the condenser. The design of the condensate collecting chamber 4 allows the device to operate under high pressure or negative pressure environment, and is applicable to both high pressure and negative pressure, that is, the working pressure range is increased, and the heat insulation effect between the environment and the upper stepped telescopic pipe 6 is improved, and the utilization rate of heat energy can be guaranteed. The air pressure value of the high pressure or negative pressure is based on the pressure value of normal pressure.

[0027] In this embodiment, the heat insulating housing 5 is a horizontal cylindrical type, which has low requirements for materials and only needs to meet simple requirements such as dust-proofing, heat preservation, and pipe fixing. The horizontal cylindrical design can effectively utilize the area, and the purpose of providing the heat insulating housing 5 is to reduce the heat dissipation from the stepped telescopic pipe 6 to the outside environment, prevent the pipe from being affected by environmental conditions, and effectively extend the service life of the pipe.

[0028] Take negative pressure heat exchange between steam and cold water in a stepped natural convection condenser as an example.

[0029] The heat exchange process is as follows: steam enters from the stepped telescopic pipe 6 at the bottom layer and naturally rises from bottom to top between the pipe rings of the heat collecting tube 1 and the steam pipe 2; cold water enters from the stepped telescopic pipe 6 at the top layer and naturally flows from top to bottom inside the heat collecting tube 1; steam and cold water form a torsional perfect natural convection heat transfer; in the process, the cold water is heated to form a medium-high temperature hot water outflow condenser; some of the hot water can be collected and used as a heat source; steam undergoes a phase change to generate condensed water; the condensed water flows rapidly along the water collecting bend to the lower layer and finally merges into the condensed water collecting chamber 4; some of the condensed water can be collected and used as a washing water source.

[0030] The condensate discharge process is as follows. Take the heat exchange in the device as an example in a negative pressure environment, steam and cold water exchange heat in a pressure environment lower than atmospheric pressure, and the generated condensate is also in the same pressure range. A gas valve is provided at the outlet of the collection chamber 4. When the device is operating, the gas valve is closed and the condensate is stored in the collection chamber 4. After the device is finished operating for one day, the gas valve is opened and the atmospheric pressure and the pressure in the pipe are balanced, and finally the pressure in the device is restored to atmospheric pressure, and the condensate flows out of the collection chamber 4. During the pressure balance process, the steam and water droplets remaining in the device are removed by air circulation, ensuring normal operation the next day.

[0031] The above description is merely a preferred embodiment of the present invention, and is not intended to limit the present invention. Those skilled in the art can make various modifications and changes to the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention. [Explanation of symbols]

[0032] 1. Stepped collector tube, 2. Stepped steam tube, 3. Water collection bend, 4. Condensate collection chamber, 5. Insulated housing, 6. Stepped telescopic pipe, 7. Telescopic U-tube, 8. Inclined flat plate.

Claims

1. A stepped natural convection condenser, comprising a stepped heat collecting tube (1), a stepped steam tube (2), a water collecting bend (3), a condensate collecting chamber (4) and a thermally insulated housing (5); The stepped heat collecting tube (1) and the stepped steam pipe (2) are coaxial and in a telescopic form to form a stepped telescopic pipe, and the pipe diameter of the stepped heat collecting tube (1) is smaller than the pipe diameter of the stepped steam pipe (2); The telescope pipes are connected in series in a staggered stepped manner for each layer, and are arranged on an inclined flat plate (8) with a predetermined gradient J. Between every two stepped telescope pipes in each layer, a telescope-type U-shaped pipe (7) is connected, and between every two stepped telescope pipes (6) are connected a telescope-type U-shaped pipe (7) and a water-collecting bend pipe (3). The shape of the water-collecting bend pipe (3) is as follows: The ellipsoidal rotation equation is satisfied. Here, x, y, and z indicate three directions constituting a spatial coordinate system, and the direction setting satisfies the right-hand rule of the Cartesian coordinate system. The condensate collecting chamber (4) is connected to a water collecting bend (3) and is provided with a gas valve and a drain, the condensate collecting chamber (4) and the stepped telescopic pipe (6) are arranged in the thermally insulated housing (5), the condensate collecting chamber (4) is located in the housing near the bottom, and the stepped telescopic pipe (6) is located above the condensate collecting chamber (4); The heat collecting pipe diameter d ｉ and steam pipe diameter d ｖ teeth, Satisfying the formula: Here, the heat transfer ratio is and h ｌ , h ｖ and represent the heat transfer coefficients between cold water and steam, respectively, in which cold water naturally flows from top to bottom within the stepped heat collection tube (1) and steam naturally flows from bottom to top between the stepped heat collection tube (1) and the stepped steam tube (2), forming twisted complete natural convection heat transfer inside and outside.

2. A steam passage is formed between the stepped steam pipe (2) and the stepped heat collecting pipe (1), and steam naturally flows from the lower inlet of the housing from bottom to top along the steam passage, with a mass flow ratio k ｍ According to the mass flow ratio k, the cold water in the heat collecting tube and the cold water in the heat collecting tube undergo natural convection heat transfer, causing a phase change and generating condensed water. ｍ teeth and Here, c ｌ is the cold water specific heat capacity, and r ｖ is the latent heat of vapor, is the cold water heat exchange temperature difference, 2. The stepped natural convection condenser according to claim 1, wherein the condensed water flows from top to bottom along the steam passage through a water collecting bend (3) into a condensed water collecting chamber (4) at the bottom of the housing, and the water collecting bend (3), whose cross-sectional shape satisfies an elliptical equation, allows the condensed water in the steam passage in the upper layer to be quickly collected in the lower layer.

3. The diameter of the stepped heat collecting pipe (1) is smaller than the diameter of the stepped steam pipe (2), and cold water flows from the upper inlet of the housing from top to bottom along the stepped heat collecting pipe (1), and the flow rate ratio is According to the flow rate ratio, natural convection heat exchange occurs between the steam outside the heat collector tube and the teeth and Here, the density ratio is and ρ ｖ , ρ ｌ 2. The stepped natural convection condenser of claim 1, wherein: ΔT is the density of steam and cold water.

4. The stepped telescopic pipes (6) are connected in series in a staggered manner for each layer, and placed on an inclined flat plate (8) with a predetermined gradient J, where J is 2% to 3%. Between the telescopic pipes of each layer, a telescopic U-tube (7) is used to connect in series with a gradient J in the horizontal direction. A flow rate control valve is provided in the telescopic pipe of each layer. The flow rate of the cold water in the heat collecting tube is expressed by the following formula 1: [0010] （１） Here, W ｍｉｎ , W ｍａｘ are the minimum and maximum production amounts of condensate water per day, respectively; λ is the flow resistance coefficient; τ is the operation time per day; g is the acceleration of gravity; and between every two layers of the telescopic pipeline, a water collecting bend (3) and a telescopic U-tube (7) are connected, and the water collecting bend (3) and the telescopic U-tube (7) are located at different ends of the upper and lower two-layer pipelines, connecting the upper layer end tube and the lower layer tip tube, where the pipe diameters of the inner and outer tubes of the telescopic U-tube (7) are d and d, respectively. ｌ and ｖ 2. The stepped natural convection condenser according to claim 1, characterized in that the ports are connected in series vertically using flanges and are removable ports.

5. 2. The stepped natural convection condenser according to claim 1, wherein the condensate collecting chamber (4) is located at the bottom of the housing, connected to the bottom water collecting bend pipe (3), and collects the condensate in the stepped telescopic pipe (6). The bottom of the collecting chamber is provided with a drain and a gas valve, and the gas valve is attached to the drain. When the condenser is operating, the gas valve is in a closed state, and the condensate is stored in the collecting chamber, maintaining an operating environment set in the condenser that is higher or lower than the normal pressure. When the condenser is completely stopped, the gas valve is opened, and the pressure in the condenser is adjusted to the normal pressure, and the condensate is discharged from the condenser.

6. 2. The stepped natural convection condenser according to claim 1, characterized in that the insulated housing (5) is horizontally cylindrical.

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