CN104729329B - A kind of non-homogeneous fin radiator for Heller type indirect air cooling system - Google Patents

Abstract

The invention discloses a non-uniform finned radiator for Heller type indirect air cooling system, said non-uniform finned radiator is divided into top, middle and bottom along the height direction, and the heights of these three regions are _h1 respectively , h ₂ and h ₃ , the top, middle and bottom cooling fin distribution pitch distribution is d ₁ , d ₂ and d ₃ ; when 0.02H≤h ₁ ≤0.25H, 0.5H≤h ₂ ≤0.96H, 0.02H ≤h ₃ ≤0.25H, 1.1d≤d ₁ ≤3.5d, d ₂ =d, 1.1d≤d ₃ ≤3.5d, where H is the length of the radiator including the cooling fins, and d is the uniform arrangement of the cooling fins fin spacing. The invention optimizes the distribution of fins, reduces the ventilation resistance at the bottom and top of the radiator, weakens the vortex in the back area of the radiator, and enhances the overall heat exchange performance of the radiator. Save a small amount of aluminum resources.

Description

A Non-Uniform Fin Radiator for Heller Type Indirect Air Cooling System

technical field

The invention relates to a non-uniform fin radiator for Heller type indirect air cooling system.

Background technique

Compared with thermal power units using wet cooling towers, dry cooling towers or direct air cooling systems can save 65%-90% of water, which is of great significance for the sustainable development of the power industry in areas rich in coal and short of water. Dry cooling system can be divided into direct air cooling system and indirect air cooling system (hereinafter referred to as intercooling system). According to the type of condenser and the arrangement position of radiator, intercooling system can be divided into Heller type and Harmon type. , SCAL type. In the intercooling system, since the heat transfer between the gas and water phases is non-contact heat transfer, the cooling limit is the dry bulb temperature of the ambient air, making the average coal consumption 3.3%-6.2% higher than that of the wet cooling unit. In addition, the working performance of the intercooling system directly affects the vacuum of the condenser and the coal consumption of power supply. The data shows that every time the water temperature at the outlet of the cooling tower decreases by 1°C, the vacuum of the condenser changes by 0.4KPa, which affects the coal consumption of power supply by about 1g/kwh.

The core components of the Heller-type intercooling system are jet condensers, intercooling towers, and Fogo-type aluminum tube and aluminum-fin radiators arranged vertically outside the tower. This type of radiator is also known as the Hungarian Forgo type. The radiator is composed of tube-finned tube bundles. The structure is an all-aluminum circular tube with large fins. The water side flow is a double flow. The main type currently used in engineering practice is the fifth-generation Heller-Fogger (Heller-Forgo) T60 type 6-row pipe and the sixth generation Fogo type 4-row pipe.

Air flowing through the radiator area is a heat-absorbing and heating-up process. During the actual operation of the Fogo radiator with evenly arranged fins, the local heat exchange area is the same as that in the middle area for the bottom and top areas of the radiator. However, Due to the influence of the ground and top sealing plates, the air flow rate is low, which will inevitably cause the local heat transfer capacity in this area to be lower than that in the middle of the radiator. Based on the optimal aerodynamic field theory of cooling towers, the aerodynamic field, temperature field and gas The more balanced the heat transfer driving force between the two phases of water, the stronger the overall heat transfer capacity. Therefore, the aerodynamic field of the radiator with evenly arranged fins is not the best matching relationship with the local heat transfer area; Different, vertical vortexes are prone to appear on the back of the radiator, resulting in local resistance, which is not conducive to the circulation of air, and is not conducive to the heat dissipation of the radiator as a whole, resulting in a decrease in the cooling efficiency of the air cooling tower.

Contents of the invention

In order to solve the disadvantages of the prior art, the present invention provides a non-uniform fin radiator for Heller type indirect air cooling system.

The present invention adopts following technical scheme:

A non-uniform fin radiator for Heller-type indirect air-cooling systems, including several cooling elements, the cooling elements include four parallel cooling tube bundles, tube sheets are arranged at both ends of the parallel cooling tube bundles, and the tube sheets are fixed On the connecting plate; the cooling tube bundle includes circular tubes, heat dissipation fins and reinforcement plates, and the heat dissipation fins and reinforcement plates are provided with reserved holes, and the circular tubes pass through the heat dissipation fins and reinforcement plates reserved holes; several cooling elements are connected in series and fixed on the connection plate to form a cooling column; the top of the cooling column is provided with a top water chamber, and the bottom of the cooling column is provided with a bottom water chamber; the tube plate is connected with bolts The connecting plate is fixed. The heat dissipation fins are aluminum heat dissipation fins, and the heat dissipation fins are formed by stamping. The circular tube, the cooling fins and the reinforcing plate are fixed by means of expansion joints. The round tube includes an aluminum tube. The material of the reinforcing plate is aluminum alloy. The shape of the reinforcing plate is like an I-beam.

The non-uniform fin radiator of the present invention is divided into three regions along the height direction: top, middle and bottom, the heights of the top, middle and bottom are h ₁ , h ₂ and h ₃ respectively, and the top, middle and bottom The distribution spacing of the heat dissipation fins in the three areas is d ₁ , d ₂ and d ₃ ; when 0.02H≤h ₁ ≤0.25H, 0.5H≤h ₂ ≤0.96H, 0.02H≤h ₃ ≤0.25H, 1.1 d≤d ₁ ≤3.5d, d ₂ =d, 1.1d≤d ₃ ≤3.5d, wherein, H is the length of the radiator including the cooling fins, and d is the fin spacing when the cooling fins are evenly arranged.

When the heights of the top, middle and bottom of the non-uniform fin radiator meet: 0.02H≤h ₁ ＝h ₃ ≤0.25H, and 0.5H≤h ₂ ≤0.96H, 1.1d≤d ₁ ＝d ₃ ≤3.5 d,d ₂ =d.

The non-uniform fin radiator is divided into top, middle and bottom along the height direction, and when the ratios of the top, middle and bottom to the total height of the non-uniform fin radiator are 5%, 85% and 10% respectively, d ₁ = 2d, d ₂ =d, d ₃ =1.8d.

The non-uniform fin radiator is divided into top, middle and bottom along the height direction, and when the ratios of the top, middle and bottom to the total height of the non-uniform fin radiator are 10%, 80% and 10% respectively, d ₁ =d ₃ =1.8d, d ₂ =d.

The non-uniform fin radiator is divided into top, middle and bottom along the height direction, and when the ratios of the top, middle and bottom to the total height of the non-uniform fin radiator are 15%, 70% and 15%, d ₁ =d ₃ =1.6d, d ₂ =d.

The non-uniform fin radiator is divided into top, middle and bottom along the height direction, and when the ratios of the top, middle and bottom to the total height of the non-uniform fin radiator are 20%, 60% and 20% respectively, d ₁ =d ₃ =1.6d, d ₂ =d.

The beneficial effects of the present invention are:

(1) The fins of the present invention optimize the distribution of the fins according to the actual wind speed distribution law outside the radiator of the Heller type air cooling tower, based on the theory of the optimal aerodynamic field of the cooling tower, and reduce the ventilation resistance at the bottom and top of the radiator , which weakens the vortex in the back area of the radiator, strengthens the heat transfer at the bottom and top of the radiator, and makes the heat transfer of the radiator more balanced along the height direction, thus enhancing the overall heat transfer performance of the radiator. At the same time, due to the reduction in the number of fins , and also save a small amount of aluminum resources;

(2) The present invention can be used not only for the fifth generation Heller-Forgo T60 type 6-row pipe, but also for the sixth generation Fogo type 4-row pipe.

Description of drawings

Fig. 1 (a) is the structural schematic diagram of Heller-Forgo T60 type aluminum round tube;

Figure 1(b) is a schematic diagram of the Heller-Forgo T60 aluminum fin structure;

Figure 2 is a schematic diagram of the structure of the cooling tube bundle;

Fig. 3 is a structural schematic diagram of a cooling element;

Fig. 4 is the structural representation of radiator of embodiment one, two, three, four;

Among them, 1. Aluminum round tube; 2. Radiating fins; 3. Aluminum round hole; 4. Turbulent flow strengthening structure; 5. Strengthening plate; 6. Tube plate; 7. Connecting plate; 8. Top water chamber; water room.

detailed description

Below in conjunction with accompanying drawing and embodiment the present invention will be further described:

Based on the above analysis of the shortcomings of the Fogo radiator with evenly arranged fins in the actual operation process, the fins of the Fogo radiator are optimized as follows: the fifth generation Heller-Forgo (Heller-Forgo) T60 Type 6 row of tubes is taken as an example to illustrate the structural composition of the non-uniform finned radiator. The present invention does not change the size, material, manufacturing process and connection method of the original finned radiator, but only makes appropriate adjustments to the distribution of the radiating fins .

The non-uniform fin radiator of the present invention is divided into three regions along the height direction: top, middle and bottom, the heights of the top, middle and bottom are h ₁ , h ₂ and h ₃ respectively, and the top, middle and bottom The distribution spacing of the heat dissipation fins in the three areas is d ₁ , d ₂ and d ₃ ; when 0.02H≤h ₁ ≤0.25H, 0.5H≤h ₂ ≤0.96H, 0.02H≤h ₃ ≤0.25H, 1.1 d≤d ₁ ≤3.5d, d ₂ =d, 1.1d≤d ₃ ≤3.5d, wherein, H is the length of the radiator including the cooling fins, and d is the fin spacing when the cooling fins are evenly arranged.

When the heights of the top, middle and bottom of the non-uniform fin radiator meet: 0.02H≤h ₁ ＝h ₃ ≤0.25H, and 0.5H≤h ₂ ≤0.96H, 1.1d≤d ₁ ＝d ₃ ≤3.5 d,d ₂ =d.

As shown in Figure 1(a), it is a schematic structural diagram of the Heller-Forgo T60 aluminum round tube. The outer diameter of the aluminum round tube 1 is 17.75mm and the thickness is 0.75mm; the heat dissipation fin 2 is made of large aluminum plate fins. The fin thickness is 0.33mm, and the original fin spacing is 2.88mm.

As shown in Figure 1(b), 4 is a turbulence-intensified structure. The aluminum round tubes 1 are misplaced, the longitudinal center distance is 30mm, and the horizontal direction is the airflow direction. Aluminum round tubes 1 are arranged in six rows with a center distance of 25mm. Formed by stamping, the aluminum round tube 1 passes through the aluminum round hole 3 reserved on the heat dissipation fin 2, and is fixed with the heat dissipation fin 2 by means of expansion joint.

Figure 2 is a schematic diagram of the structure of the cooling tube bundle. In the figure, the reinforcing plate 5 is made of aluminum alloy, looks like an I-beam, is 170mm high, 599mm long, and 6mm thick, with a hole in the middle through which the aluminum round tube 1 passes; each tube bundle consists of 60 tubes with a length of 4840mm Aluminum round tube 1.

Fig. 3 is a schematic diagram of the structure of the cooling element. In the figure, the material of the tube plate 6 is aluminum alloy, and there are tube holes and bolt holes; four cooling tube bundles are connected in parallel by the tube plate 6 to form a cooling element, which is the most basic unit of the radiator, and it is connected in series to form various The length of the cooling column, that is, the radiator.

Figure 4 is a schematic diagram of the structure of the radiator. Each cooling column is composed of several cooling elements connected in series. The tube plates at both ends are fixed to the connecting plate 7 with bolts. The top of the cooling column is connected to the top water chamber 8, and the bottom is connected to the bottom water chamber 9. , The water chamber and the tube sheet are fixed with bolts.

Embodiment one:

In this embodiment, the heat sink is divided into three parts according to the height direction, the top, the middle, and the bottom. The proportions of the three parts to the total height are 5%, 85% and 10% respectively, and the top fin spacing d ₁ =2d=5.76mm, The pitch of the bottom fins is d ₃ =1.8d=5.184mm, and other parameters of the fins remain unchanged, where d is the fin pitch when the cooling fins are evenly arranged, 2.88mm.

Embodiment two:

In this embodiment, the heat sink is divided into three parts according to the height direction, the top, the middle, and the bottom. The proportions of the three parts to the total height are 10%, 80% and 10% respectively, and the fin pitch at the top and bottom is d ₁ =d ₃ = 1.8d = 5.184mm, other parameters of the fin remain unchanged.

Embodiment three:

In this embodiment, the radiator is divided into three parts according to the height direction, the top, the middle, and the bottom. The proportions of the three parts to the total height are 15%, 70% and 15% respectively, and the fin pitch at the top and bottom is d ₁ =d ₃ = 1.6d = 4.608mm, other parameters of the fin remain unchanged.

Embodiment four:

In this embodiment, the heat sink is divided into three parts according to the height direction, the top, the middle part and the bottom. The proportions of the three parts to the total height are 20%, 60% and 20% respectively, and the fin pitch at the top and bottom is d ₁ =d ₃ = 1.2d = 4.032mm, other parameters of the fin remain unchanged.

Heat dissipation principle of the present invention is:

(1) When the radiator fins are evenly arranged along the height direction

The distribution law of the air flow velocity along the height direction at the entrance of the radiator is as follows: due to the influence of the ground resistance, the wind speed is small at the lower position, and gradually increases with the increase of the height, and the wind speed reaches about the middle range of the radiator. The largest, the top area of the radiator, due to the influence of the top sealing plate between the radiator and the tower edge, the wind speed becomes smaller, because the local heat dissipation area is the same, so the local heat dissipation is different along the height direction, the top and bottom areas of the radiator The heat dissipation capacity of the radiator is not maximized; the air flows through the radiator and then enters the air cooling tower. Along the height direction of the radiator, the air flow velocity is different, which is easy to generate longitudinal vortices, forming local resistance, which is not conducive to the circulation of air, and is not conducive to the cooling of the radiator as a whole. Heat dissipation, resulting in a reduction in the cooling efficiency of the air-cooling tower.

(2) When the radiator fins are unevenly arranged along the height direction

(2.1) When the fin distribution spacing of the top and bottom of the radiator is not equal to that of the middle part, due to the increase of the fin spacing at the top and bottom, the local resistance of the radiator is reduced, the air flow rate increases, and the ventilation in this area The increase of the amount makes the local heat dissipation area in this area more matched with the air velocity, and the local heat dissipation capacity is improved. Based on the theoretical analysis of the optimal aerodynamic field of the cooling tower, it can be known that the overall heat dissipation effect is better than that of the radiator with evenly arranged fins.

(2.2) Due to the increased air velocity in the top and bottom radiator regions, the air velocity in the back region of the radiator is more balanced along the height direction, thus weakening the generation ability of the longitudinal vortex in this region and the local resistance brought by the vortex , which is more conducive to the heat dissipation of the radiator.

Although the specific implementation of the present invention has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims (6)

1. the non-homogeneous fin radiator for Heller type indirect air cooling system, it is characterised in that described non-homogeneous fin dissipates Hot device is divided into top, middle part and region, three, bottom along short transverse, and the height of described top, middle part and bottom is respectively h₁、h₂ And h₃, the trizonal radiating fin in described top, middle part and bottom distribution spacing is distributed as d₁、d₂And d₃；When 0.02H≤h₁≤ 0.25H, 0.5H≤h₂≤ 0.96H, 0.02H≤h₃During≤0.25H, 1.1d≤d₁≤ 3.5d, d₂=d, 1.1d≤d₃≤ 3.5d, Wherein, H is the radiator length comprising radiating fin, and d is radiating fin spacing of fin when being evenly arranged.

A kind of non-homogeneous fin radiator for Heller type indirect air cooling system, it is characterised in that When the height of top, middle part and the bottom of described non-homogeneous fin radiator meets: 0.02H≤h₁=h₃≤ 0.25H, and 0.5H≤h₂During≤0.96H, 1.1d≤d₁=d₃≤ 3.5d, d₂=d.

A kind of non-homogeneous fin radiator for Heller type indirect air cooling system, it is characterised in that Described non-homogeneous fin radiator is divided into top, middle part and bottom, described top, middle part and bottom to account for non-homogeneous wing along short transverse When the ratio of sheet heat radiator total height is respectively 5%, 85% and 10%, d₁=2d, d₂=d, d₃=1.8d.

A kind of non-homogeneous fin radiator for Heller type indirect air cooling system, it is characterised in that Described non-homogeneous fin radiator is divided into top, middle part and bottom, described top, middle part and bottom to account for non-homogeneous wing along short transverse When the ratio of sheet heat radiator total height is respectively 10%, 80% and 10%, d₁=d₃=1.8d, d₂=d.

A kind of non-homogeneous fin radiator for Heller type indirect air cooling system, it is characterised in that Described non-homogeneous fin radiator is divided into top, middle part and bottom, described top, middle part and bottom to account for non-homogeneous wing along short transverse When the ratio of sheet heat radiator total height is respectively 15%, 70% and 15%, d₁=d₃=1.6d, d₂=d.

A kind of non-homogeneous fin radiator for Heller type indirect air cooling system, it is characterised in that Described non-homogeneous fin radiator is divided into top, middle part and bottom, described top, middle part and bottom to account for non-homogeneous wing along short transverse When the ratio of sheet heat radiator total height is respectively 20%, 60% and 20%, d₁=d₃=1.6d, d₂=d.