CN1431451A - Condenser with shaped strengthened tubes supported by hollow ring and enhanced method for transferring heat - Google Patents

Abstract

The invention provides a hollow ring-supported special-shaped reinforced tube condenser, which includes a shell, a heat exchange tube, and a support between tubes. The heat exchange tube is installed in the shell, and the support between the tubes is installed between the heat exchange tubes and connected to the heat exchange The tubes are connected; the support between the tubes is a hollow ring mesh plate, and the heat exchange tube is supported by a point support or a line support connection; the heat exchange tube is a special-shaped heat transfer tube with a non-smooth wall surface; it can be a scaling tube, a rhombus Finned tube, cross-grained tube or spiral grooved tube; a method for enhancing heat transfer in a condenser, using a hollow ring plate with a high void ratio in the axial flow channel, a large flow cross section, and minimal physical resistance to the longitudinal fluid in the shell side , so that the heat transfer temperature difference loss of steam to cold flow is minimized, and the driving force of heat transfer to cold flow is improved; the invention can reduce the steam flow resistance on the shell side, minimize the heat transfer temperature difference loss of steam to cold flow, and improve condensation The driving force of heat transfer can strengthen the heat transfer of convection in the tube and condensation outside the tube, and improve the total heat transfer coefficient and the heat transfer performance of the condenser.

Description

Condenser with special-shaped reinforced tube supported by hollow ring and method for enhancing heat transfer

technical field

The invention relates to heat exchanger technology, in particular to a hollow ring-supported special-shaped reinforced tube condenser and a heat transfer strengthening method.

Background technique

Condensers used in industry have a variety of structures. In terms of the structure of the support between the tubes, there are mainly single-bow baffles, double-bow baffles, and dish-ring baffles. The commonly used condensers are single There are many structures supporting tube bundles by bow baffles, and the heat exchange tubes are mainly smooth heat transfer tubes. The steam between the condenser tubes baffles back and forth between the baffles and scours the tube bundles. The fluid shape resistance caused by baffles is large, and the steam The pressure drop is large, and the steam pressure at the shell-side outlet of the condenser is much lower than the shell-side inlet pressure, resulting in a relatively large drop in the steam temperature at the shell-side outlet section compared with the inlet section, which reduces the heat transfer temperature difference to the tube-side fluid and reduces the The heat transfer efficiency of the condenser and the heat transfer film coefficient of the smooth heat transfer tube are low, which is also a main reason for the low heat transfer performance of the current industrial condenser. Patent No. 89218385.3 Chinese utility model "shell-and-tube heat exchanger tube support" discloses a hollow ring mesh plate, using this hollow ring mesh plate as a tube support can make the single-phase fluid heat exchanger The fluid on the shell side flows in the axial direction, which greatly reduces the loss of physical resistance caused by back-and-forth baffles. This support structure between tubes can also be used for reference in condensers for multi-phase flow. By reducing the steam resistance on the shell side, the loss of heat transfer temperature difference can be reduced. the goal of.

Contents of the invention

The purpose of the present invention is to overcome the disadvantages and deficiencies of the existing baffle-type structure of the condenser tubes of large steam flow resistance, large heat transfer temperature difference loss, small heat transfer film coefficient and poor heat transfer performance of smooth heat transfer tubes, Research and design a method that can effectively reduce the shell-side steam flow resistance and reduce the loss of heat transfer temperature difference. At the same time, according to the specific situation of heat transfer resistance control inside and outside the heat transfer tube, reasonably select high-efficiency special-shaped heat transfer tubes to improve the overall heat transfer coefficient. The hollow ring supports the special-shaped reinforced tube condenser.

Another object of the present invention is to provide a heat transfer enhancement method applied to the hollow ring-supported special-shaped enhanced tube condenser.

The purpose of the present invention is achieved through the following technical solutions: the hollow ring supported special-shaped reinforced tube condenser includes a shell, a heat exchange tube, and a support between the tubes, the heat exchange tube is installed in the shell, and the support between the tubes is installed on the heat exchange tube The space between them is connected with the heat exchange tubes; the support between the tubes is a hollow ring mesh plate, and the heat exchange tubes are supported by a point support or a line support connection.

The structural form of the support between pipes is a pipe joint hollow ring or a helical hollow ring.

The heat exchange tube is a special-shaped heat transfer tube with a non-smooth wall surface; it can be a zoom tube with periodic expansion and contraction along the axial direction and a tapered shape change in the circumferential direction, or a periodical circumferential discontinuous three-dimensional fin along the axial direction. Diamond-shaped finned tubes, or horizontally or spirally grooved tubes with periodic circumferential grooves along the axial direction.

The heat transfer enhancement method of the present invention is as follows: the void ratio of the axial channel of the hollow ring screen plate is high, the flow cross section is large, and the physical resistance to the longitudinal fluid in the shell side is extremely small, so that the heat transfer temperature difference loss of the steam to the cold flow is reduced. To the minimum, improve the driving force of convective heat transfer.

The heat transfer enhancement method can simultaneously utilize the non-smooth heat transfer wall surface of the special-shaped heat transfer tube to enhance convective heat transfer and condensation heat transfer inside and outside the tube.

Compared with the prior art, the present invention has the following advantages and effects: ① Replace the existing baffle plate with the hollow ring screen as the support between the shell side tubes, which can effectively reduce the steam flow resistance on the shell side and make the steam The heat transfer temperature difference loss of the cold flow is minimized, and the driving force of condensation heat transfer is improved; ② The existing smooth heat transfer tube is replaced by a special-shaped heat transfer tube, which can strengthen the heat transfer of convection inside the tube and condensation outside the tube, and effectively improve the total heat transfer. The thermal coefficient improves the heat transfer performance of the condenser. Under the effect of the above two improvement factors, compared with the existing technology, the condenser can greatly reduce the area and material of the condenser when the heat transfer process conditions remain unchanged. consumption, or greatly increase the heat transfer load of the condenser when the condenser area remains the same.

Description of drawings

Figure 1 is a schematic structural view of a hollow ring-supported special-shaped reinforced tube condenser.

Fig. 2 is a schematic cross-sectional view along the line A-A of Fig. 1 .

Fig. 3 is a schematic structural view of the hollow ring screen used in Fig. 1 .

FIG. 4 is a schematic structural diagram of the zoom tube used in FIG. 1 .

Fig. 5 is a schematic diagram of the structure of the rhombic finned tube used in Fig. 1 .

Fig. 6 is a schematic diagram of the structure of the horizontally grooved pipe used in Fig. 1 .

Fig. 7 is a schematic diagram of the structure of the spirally grooved pipe used in Fig. 1 .

Detailed ways

The present invention will be described in further detail below with reference to the accompanying drawings and examples, but the embodiments of the present invention are not limited thereto.

Example

Fig. 1 and Fig. 2 have shown the concrete structure of the present invention, seen by Fig. 1, this hollow ring support special-shaped strengthened tube condenser is made up of shell side steam inlet pipe 1 of heat exchanger, shell side inlet ring sleeve 2, hollow ring Mesh plate 3, special-shaped heat transfer tube 4, condenser shell 5, lower tube plate 6, lower head 7, cold flow inlet pipe 8, shell side condensate outlet pipe 9, upper tube plate 10, upper head 11, The cold flow outlet pipes 12 are installed and connected together, and their mutual positions and connection relationship are as follows: the special-shaped heat transfer tubes 4 and the upper and lower tube sheets 10 and 6 are connected by welding or expansion tubes and then placed in the condenser shell 5. The hollow ring screen plate 3 is arranged between the heat transfer tubes 4 at a certain distance, and supports the special-shaped heat transfer tubes 4 in the form of point support or line support. The steam inlet pipe 1 of the shell is welded on the side of the inlet ring sleeve 2 on the shell side. The shell-side inlet ring 2 is welded to the condenser shell 5 and the upper tube plate 10, the lower end of the condenser shell 5 is welded to the lower tube plate 6, and the shell-side condensate outlet pipe is connected to the side of the condenser shell 5 9. The upper and lower tube sheets 10, 6 are respectively connected with the upper and lower heads 11, 7, and connected with the cold flow inlet 8 and outlet 12 to form the tube-side flow path of the condenser. Among them: the shape of the hollow ring stencil 4 is shown in Figure 3, and the structural form is a pipe joint hollow ring, which can be formed by short pipe joints, vertical and horizontal flat steel and frame welding, or can be formed by stamping forgings, or cast modules ; The special-shaped heat transfer tube 4 can be a zoom tube with periodic expansion and contraction circumferential tapered shape changes along the axial direction as shown in Figure 4; Finned diamond-shaped finned tubes; or horizontally grooved tubes with periodic circumferential grooves along the axial direction as shown in Figure 6 or spiral grooved tubes as shown in Figure 7 .

Claims (8)

1, a kind of cavity ring supports special-shaped enhanced tube condenser, comprises support between housing, heat exchanger tube, pipe, and heat exchanger tube is installed in the housing, and support is installed between the heat exchanger tube and with heat exchanger tube and is connected between pipe; It is characterized in that: support is the cavity ring web plate between described pipe, with a supporting or line bearing connected mode supporting heat exchanger tube.

2, cavity ring according to claim 1 supports special-shaped enhanced tube condenser, it is characterized in that: the version of support is tube coupling cavity ring or helix cavity ring between described pipe.

3, cavity ring according to claim 1 supports special-shaped enhanced tube condenser, it is characterized in that: described heat exchanger tube is the special-shaped heat-transfer pipe of non-hydraulically smooth surface.

4, cavity ring according to claim 3 supports special-shaped enhanced tube condenser, it is characterized in that: described special-shaped heat-transfer pipe is vertically with periodic dilation and the convergent-divergent pipe that shrinks circumferential conical surface change of shape

5, cavity ring according to claim 3 supports special-shaped enhanced tube condenser, it is characterized in that: described special-shaped heat-transfer pipe is vertically with the lozenge fin tube of circumferential discontinuous three-dimension fin periodically

5, cavity ring according to claim 3 supports special-shaped enhanced tube condenser, it is characterized in that: described special-shaped heat-transfer pipe is vertically with periodically the band pipe or the spiral grooved tube of circumferential recess.

6, a kind of cavity ring supports special-shaped enhanced tube condenser heat transfer enhancing method, it is characterized in that: the shaft orientation flowing channel voidage height that utilizes the cavity ring web plate, flow cross is big, body resistance to the vertical fluid of shell side is minimum, make steam reduce to minimum, improve the cold flow driving force of heat transfer to the heat transfer temperature loss of cold flow.

7, cavity ring according to claim 6 supports special-shaped enhanced tube condenser heat transfer enhancing method, it is characterized in that: non-smooth heat transfer wall enhanced tube is interior and pipe is outer convection heat transfer' heat-transfer by convection and the condensation heat transfer that utilize special-shaped heat-transfer pipe.

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