CN204854428U - A MGGH heat exchange system - Google Patents

Abstract

The utility model discloses an MGGH heat exchange system, which comprises a heating heat exchanger, desulfurization and dust removal equipment, and a cooling heat exchanger arranged in sequence. Pipelines are connected to the heating heat exchanger and the cooling heat exchanger to form a closed loop. There are medium compensation tanks, circulation pumps and medium heaters. Both the heating and cooling heat exchangers include shells, combiner boxes and plate heat exchange modules. The upper and lower ends of the shell are provided with smoke inlet channels and smoke exhaust channels. Both the exhaust channel and the smoke exhaust channel are composed of flanges and guide cylinders; the plate heat exchange module includes several heat exchange plates, and there are flue support protrusions and medium channel support protrusions on both sides of the heat exchange plates. The heat transfer medium folding flow channel is formed between the medium channel support protrusions, and the exhaust smoke primary flow channel is formed between the flue support protrusions. The heat exchange system has low energy consumption for flue gas treatment, simple structure, low input and operating costs, reliable operation, high heat exchange efficiency, easy cleaning and maintenance, and the heat exchanger has high strength and long service life.

Description

A MGGH heat exchange system

technical field

The utility model relates to the technical field of smoke exhaust treatment equipment in the electric power industry, in particular to an MGGH heat exchange system.

Background technique

In order to meet the requirements of GB13553-2011 "Emission Standards of Air Pollutants for Thermal Power Plants", coal-fired power generation enterprises need to carry out corresponding desulfurization treatment before exhausting smoke. There are two types of flue gas heat exchangers (RGGH) and intermediate heat medium flue gas heat exchangers (MGGH). Among them, MGGH has great market prospects due to its advantages in energy saving, operating economy and reliability.

MGGH uses the high-temperature heating medium of the original smoke to reduce the temperature of the flue gas, reduce the flow rate of the flue gas, improve the performance of the flue gas treatment, and then use the medium to heat the low-temperature clean flue gas to increase the discharge temperature and make it easy to dissipate; the existing MGGH Most of them are tube type and fin type. The flue gas is in contact with the surface of the cooling water pipe to exchange heat. The contact area is small, the heat exchange stroke is too long, the pressure drop of the exhaust gas is large, and the design and arrangement of the heat exchange tube bundle cannot be fully utilized. At the same time, due to the vertical contact between the flue gas and the heat exchange tube, the smoke exhaust resistance is large, and the leeward side of the cooling water pipe and the stagnation area are easy to accumulate dust, which is difficult to clean, resulting in poor heat transfer performance. reduce.

Utility model content

The technical problem to be solved by the utility model is to overcome the deficiencies in the prior art and provide an MGGH heat exchange system with compact structure, low smoke exhaust resistance, convenient cleaning and high heat exchange efficiency.

A MGGH heat exchange system of the utility model is realized through the following technical scheme, which includes a heating heat exchanger, a desulfurization and dust removal equipment, and a cooling heat exchanger arranged sequentially on the flue gas discharge pipe, and the piping connecting the heating heat exchanger The medium inlet and the medium outlet of the cooling heat exchanger, as well as the pipeline connecting the medium outlet of the heating heat exchanger and the medium inlet of the cooling heat exchanger, form a closed circulation loop of the heat transfer medium, and the closed circulation loop is equipped with a medium compensation tank and circulation pumps and medium heaters;

Among them, both the heating heat exchanger and the cooling heat exchanger include:

The shell has a smoke inlet channel and a smoke exhaust channel at its upper and lower ends. The smoke inlet channel is composed of an inlet flange and a smoke guide tube. The smoke exhaust channel is composed of an outlet flange and a smoke guide tube. The smoke guide tube and The inner wall of the smoke guide cylinder is provided with a smoke guide slope;

A combiner box connected to the shell, with medium inlet and medium outlet respectively located at its two ends;

And the plate heat exchange module located inside the shell, one end of which is connected to the combiner box, the plate heat exchange module includes several heat exchange plates evenly arranged parallel to the smoke exhaust direction, and the two sides of the heat exchange plates are respectively equipped with flue channels Support protrusions and medium channel support protrusions, the medium channel support protrusions of adjacent heat exchange plates abut or the medium channel support protrusions abut and connect with the plate plane of the heat exchange plate, forming a seal connecting the medium inlet and the medium outlet The heat transfer medium folded flow channel, the heat transfer medium folded flow channel includes several circumferential channels with independent medium inlets and outlets and the split partitions arranged in the circumferential channels to allow the heat transfer medium to reciprocate along the circumferential channel. A smoke exhaust primary flow channel is formed between the flue support protrusions adjacent to the heat exchange plate.

Further, temperature transmitters are installed in the smoke exhaust passages of the heating heat exchanger and the cooling heat exchanger, the medium heater is also connected with a heating solenoid valve, and the closed circulation loop is also provided with a medium inlet and a medium connected to the cooling heat exchanger. The bypass branch of the medium outlet is equipped with a bypass solenoid valve, the temperature transmitter on the heating heat exchanger is electrically connected to the heating solenoid valve, and the temperature transmitter on the cooling heat exchanger is connected to the bypass The solenoid valve is electrically connected.

Further, there is at least one dividing plate, the number of folded paths of the heat transfer medium is an even number, the combiner box is located on one side of the shell, and a divider is arranged inside it, and the divider isolates the inside of the combiner box from the medium inlet. A connected inlet diversion area and an outlet confluence area connected with the medium outlet.

Furthermore, there is at least one dividing plate, the number of folding paths of the heat transfer medium is an odd number, and the combiner box is composed of two sub-housings located on both sides of the casing.

Further, the media channel support protrusion and the flue support protrusion are stamped corrugated protrusions, welding ribs or plate ribs.

Further, an elastic body is provided between the other end of the plate heat exchange module and the casing, and the elastic body is a spring or rubber.

Further, a flexible plate is provided between the other end of the plate heat exchange module and the housing, and the flexible plate includes an L-shaped backing plate that is integrally formed and clamped against the end corner of the plate heat exchange module, and is in close contact with the side of the housing. The positioning fixing plate and the bent bending plate connecting the L-shaped backing plate and the fixing plate.

The beneficial effects of the utility model are:

1. Under the cyclical heat exchange of the heat transfer medium in the closed loop, the heat of the original smoke is used to heat the clean flue gas, which can realize low energy consumption flue gas treatment, and the flue gas treatment effect is remarkable. At the same time, the structure is simple, and it is easy to put into operation. Low cost and reliable operation;

2. When the exhaust smoke passes through the cooling heat exchanger and the heating heat exchanger, under the guidance of the smoke guide slope of the smoke inlet guide cylinder, the flow field of the exhaust smoke is evenly distributed in the plate heat exchange module, and the wall surface appears cold and hot. Equilibrium phenomenon, improve heat transfer efficiency;

3. The exhaust smoke performs multi-pass cross-current heat exchange with the heat transfer medium in the heat exchange module, and the mutual contact area is large. Therefore, the heat exchange stroke can be shortened to a large extent, and the structure of the heat exchanger is more compact, which is easier to install in On the exhaust pipe or chimney, and the distance between the heating heat exchanger and the cooling heat exchanger is not limited;

4. There are supporting protrusions on both sides of the heat exchange plate, which can not only form the heat transfer medium and smoke exhaust channel, but also improve the ability of the heat exchange plate to withstand the pressure difference on both sides, and prevent the seal failure caused by the deformation of the heat exchange plate problem, and the plate heat exchange module itself is a module that can independently realize sealed heat exchange, and does not need to be sealed with the side of the shell. Therefore, it is reliable for long-term operation and easy to carry out modular assembly.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is a schematic structural view of the heating heat exchanger in Fig. 1;

Fig. 3 is a schematic structural diagram of the flexible board in Fig. 2;

Fig. 4 is a schematic diagram of the reverse flow mode of the heat exchange plate pair of the present invention;

Fig. 5 is a schematic diagram of the forward flow mode of the heat exchange plate pair of the present invention.

In the figure: 1. Heating heat exchanger, 10. Shell, 11. Flexible plate, 111. Fixed plate, 112. Bending plate, 113. L-shaped backing plate, 12. Plate heat exchange module, 121. Exchanger Hot plate pair, 1211. Partition partition, 1212. Circumferential channel, 1213. Flue support protrusion, 1214. Medium channel support protrusion, 13. Smoke exhaust channel, 131. Outlet flange, 132. Smoke exhaust guide Tube, 14. Smoke inlet channel, 141. Inlet flange, 142. Smoke inlet guide tube, 15. Combiner box, 16. Medium outlet, 17. Medium inlet, 18. Combiner box cover plate, 19. Partition plate, 2. Cooling heat exchanger, 3. Bypass solenoid valve, 4. Medium compensation tank, 5. Circulation pump, 6. Medium heater, 7. Heating solenoid valve, 8. Desulfurization and dust removal equipment;

A: smoke exhaust, B: heat transfer medium (it can be liquid with high heat transfer coefficient such as water, coolant or oil).

Detailed ways

In order to enable those skilled in the art to better understand the technical solution of the utility model, the utility model will be further described in detail below in conjunction with the accompanying drawings and preferred embodiments.

As shown in Figure 1-5, a plate-type low-temperature economizer of the present invention includes a heating heat exchanger 1, a desulfurization and dust removal equipment 8, and a cooling heat exchanger 2 arranged on the flue gas discharge pipe in sequence, and the pipes are connected The medium inlet 17 of the heating heat exchanger 1 and the medium outlet 16 of the cooling heat exchanger 2, and the pipeline connecting the medium outlet 16 of the heating heat exchanger 1 and the medium inlet 17 of the cooling heat exchanger 2 form a closed cycle of heat transfer medium loop, the closed circulation loop is provided with a medium compensation tank 4, a circulation pump 5 and a medium heater 6, the medium compensation tank 4 can supplement the heat transfer medium in the closed circulation loop, stabilize the medium pressure in the loop, and the circulation pump 5 provides heat transfer Medium circulation power, the medium heater 6 is set at the rear end of the medium inlet 17 of the heating heat exchanger 1, and heats the heat transfer medium entering the heating heat exchanger 1 to ensure the exhaust gas temperature;

Wherein, the structure of the heating heat exchanger 1 and the cooling heat exchanger 2 is consistent, and they both include:

The casing 10 has a smoke inlet channel 14 and a smoke exhaust channel 13 at its upper and lower ends. The smoke inlet channel 14 is composed of an inlet flange 141 and a smoke inlet guide tube 142. The smoke exhaust channel 13 is formed by an outlet flange 131 and a smoke exhaust guide. The inner wall of the smoke inlet guide cylinder 142 and the smoke exhaust guide cylinder 132 is provided with a smoke guide slope, that is, the smoke inlet guide cylinder 142 and the smoke exhaust guide cylinder 132 have a tapered inner cavity, or the smoke inlet guide cylinder 142 and the exhaust gas guide cylinder 142 have a conical inner cavity. The four walls of the inner cavity of the smoke guiding cylinder 132 are inclined walls forming an angle greater than 0° with the smoke exhaust direction, which can be selected according to the needs and the shape of the housing 10; meanwhile, the upper and lower ports of the housing 10 are also provided with pull rods or Tension bars (not shown in the figure) are used to fix and limit the plate heat exchange module 12;

A combiner box 15 communicating with the housing 10, a medium inlet 17 and a medium outlet 16 are respectively arranged at its two ends;

And the plate heat exchange module 12 located inside the housing 10, one end of which is connected to the combiner box 15, the plate heat exchange module 12 includes several heat exchange plates evenly arranged parallel to the smoke exhaust direction, the two sides of the heat exchange plates are respectively There are flue support protrusions 1213 and medium channel support protrusions 1214, the medium channel support protrusions 1214 of adjacent heat exchange plates abut against each other, or the medium channel support protrusions 1214 on one heat exchange plate and the other heat exchange plate The planes of the upper plate are abutted against each other and connected to form a sealed heat transfer medium folded flow channel connecting the medium inlet 17 and the medium outlet 16. The heat transfer medium folded flow channel includes several circumferential channels 1212 with independent medium inlets and outlets and arranged in the circumferential channel. In 1212, the partition plate 1211 that makes the heat transfer medium flow back and forth along the circumferential channel 1212, and the smoke exhaust primary flow channel is formed between the flue support protrusions 1213 of adjacent heat exchange plates, and the adjacent heat exchange plates The flue support protrusions 1213 form a channel for the primary flow of smoke. The flue support protrusions 1213 can be connected against each other, or the flue support protrusions 1213 can be connected with the plate plane of the heat exchange plate to prevent Thermal expansion and deformation, the flow direction of the exhaust gas and the heat transfer medium are perpendicular to each other, and they flow through the plate heat exchange module 12 in a staggered countercurrent for heat exchange;

As shown in Figure 4, the dividing partition 1211 divides the circumferential channel 1212 into an inlet and outlet channel and a folding channel. The width of the inlet and outlet channels and the width of the folding channel can be the same or different; It can be different; the number of folds and the width of each channel can be adjusted according to needs;

After the two heat exchange plates are superimposed, resistance welding or adhesive connection is carried out on the media channel support protrusions 1214 on both sides of the circumferential channel 1212 and the media channel support protrusions 1214 as the partition plate 1211. The two sides of the circumferential channel 1212 Side continuous welding forms a sealed medium-folding flow channel, and the split-pass separator 1211 can be pressed into contact connection, continuous welding, intermittent welding or multi-spot welding to form a heat exchange plate pair 121 with a sealed multi-pass folding flow channel inside; The pressure of the heat transfer medium in the pair 121 is greater than the exhaust pressure between the heat exchange plate pairs 121; the flue support protrusions 1213 between the heat exchange plate pairs 121 abut against each other or the flue support protrusions 1213 abut against the plate plane , to form a smoke exhaust primary flow channel parallel to the exhaust gas flow direction; the medium channel support protrusion 1214 and the flue support protrusion 1213 can be stamped corrugated protrusions, welding ribs or plate ribs, the medium channel support protrusion 1214 and the flue channel The support protrusions 1213 are symmetrical or asymmetrical, that is, the depths of the protrusions on both sides of the heat exchange plate can be equal or unequal; It can form channels for heat transfer medium and smoke exhaust, and at the same time support each other, improve the ability of the heat exchange plate to withstand the pressure difference on both sides, and prevent the problem of seal failure caused by the deformation of the heat exchange plate, and the plate heat exchange module 12 itself is a The module that can independently realize sealed heat exchange does not need to be sealed with the side of the housing 10, so it is reliable in long-term operation and easy to carry out modular assembly and mass production;

The heat exchange plate can be made of carbon steel, stainless steel, titanium and its alloys, nickel and its nickel-based alloys, or other steel types or non-ferrous metals, and its temperature resistance range is -196 to 1200 °C.

Therefore, compared with the prior art, the MGGH of this utility model first enters the cooling heat exchanger 2 to exchange heat with the heat transfer medium to realize cooling. Sufficient desulfurization and dust removal are carried out in the desulfurization and dust removal equipment 8 located at the front end of the cooling heat exchanger 2 to effectively reduce the sulfur content of the exhaust gas; It flows in the closed circulation loop, releases heat in the heating heat exchanger 1, heats the treated clean flue gas, increases the discharge temperature of the clean flue gas, and prevents the clean flue gas from being adsorbed by condensed water vapor to corrode the flue or chimney, making the clean flue gas The flue gas rises to the high altitude more easily and quickly to dissipate; therefore, the heat exchange system can realize low energy consumption flue gas treatment, and the flue gas treatment effect is remarkable. At the same time, the structure is simple, the input and operation costs are low, and the use is reliable;

As shown in Figure 2, when the exhaust smoke passes through the cooling heat exchanger 2 and the heating heat exchanger 1, under the guidance of the conical smoke inlet guide cylinder 142, the exhaust smoke is evenly distributed in the flow field in the plate heat exchange module 12 , there is an imbalance of cold and heat on the wall surface, which improves the heat exchange efficiency; the exhaust smoke performs multi-pass cross-current heat exchange with the heat transfer medium in the heat exchange module, and the mutual contact area is large. Therefore, the heat exchange stroke can be shortened to a large extent. The structure of the heat exchanger is more compact, and it is easier to install on the exhaust pipe or chimney; the heat exchange plate is arranged parallel to the flow direction of the exhaust gas, and the resistance of the exhaust smoke is small. At the same time, the inside of the heat exchanger is easy to clean and maintain; the two heat exchange plates The sides are respectively provided with supporting protrusions, which can not only form the heat transfer medium and the smoke exhaust channel 13, but also improve the ability of the heat exchange plate to withstand the pressure difference on both sides.

As shown in Figure 1, temperature transmitters are installed in the smoke exhaust passages 13 of the heating heat exchanger 1 and the cooling heat exchanger 2, the medium heater 6 is also connected with a heating solenoid valve 7, and the closed circulation loop is also provided with a communication A bypass branch of the medium inlet 17 and the medium outlet 16 of the cooling heat exchanger 2, the bypass solenoid valve 3 is provided on the bypass branch, and the temperature transmitter on the heating heat exchanger 1 is electrically connected with the heating solenoid valve 7 , the temperature transmitter on the cooling heat exchanger 2 is electrically connected to the bypass solenoid valve 3, and the heating solenoid valve 7 and the bypass solenoid valve 3 respectively activate the medium heater 6 or the bypass solenoid valve according to the exhaust gas temperature in the exhaust gas passage 13. On the basis of meeting the flue gas treatment requirements, unnecessary energy consumption can be further saved.

In this example, there is at least one dividing plate 1211, the number of folded paths of the heat transfer medium is an even number, the inlet and outlet of the heat transfer medium are on the same side, the combiner box 15 is located on the side of the shell 10, and the structure is compact. One side of the side can also be provided with detachable combiner box cover plate 18, is convenient to clean up and the flow path in the plate heat exchange module 12 of maintenance, combiner box 15 interior is provided with divider 19, divider 19 isolates the inside combiner box 15 It forms an inlet diverging area connected with the medium inlet 17 and an outlet converging area connected with the medium outlet 16; when the division partition 1211 is an even number, the medium completes an odd number of folds in the circumferential channel 1212, and the medium inlet and outlet are on different sides. , the direction of flow in and out is the same, and the combiner box 15 is composed of two sub-shells 10 located on both sides of the shell 10 .

As shown in Figure 4, when the heat transfer medium flows in the reverse direction, after the heat exchange plates are stacked, the vertical direction is used as the inlet and outlet channels for the smoke exhaust, that is, the exhaust smoke is guided by the smoke inlet guide tube 142 and enters from below, and flows through once. The plate flows out from the top, and the heat transfer medium flows in the horizontal reciprocating folding process, enters from the first channel opening below the side, and flows out from the first channel opening above the side after passing through multiple folding processes, that is, the cold source enters and exits as Reverse flow; Of course, the two flow directions can also be reversed, and the flow direction described above is the most preferred.

As shown in Figure 5, when the heat transfer medium flows in the forward direction, after the heat exchange plates are stacked, the vertical direction is used as the inlet and outlet channels for the smoke exhaust, that is, the exhaust smoke is guided by the smoke inlet guide tube 142 and enters from the top, and the primary flow Pass through the plate and flow out from the bottom, the heat transfer medium flows in the horizontal reciprocating folding process, enters from the first channel opening below one end of the side, and flows out from the first channel opening above the other end of the side after passing through multiple folding processes, that is The flow in and out of the heat transfer medium is forward flow; of course, the flow direction of the two can also be reversed.

In this example, the other end of the plate heat exchange module 12 is flexibly connected to the shell 10. When heated, the heat transfer plates in the plate heat exchange module 12 expand and deform, and mutual extrusion is prone to seal failure and medium leakage. Mixed, the function of the heat exchanger is invalid, and the flexible deformation space is preset between the other end of the plate heat exchange module 12 and the shell 10 to absorb thermal expansion deformation and improve the life of the condenser. The flexible connection can pass through the plate heat exchange module 12 The other end of the plate heat exchange module 12 is provided with an elastic body between the housing 10, and the elastic body is a spring or rubber. It can also be realized by installing a flexible plate 11 between the other end of the plate heat exchange module 12 and the housing 10, as shown in Figure 3 As shown, the flexible plate 11 includes an L-shaped backing plate 113 that is bent to form a card against the end corner of the plate heat exchange module 12, a fixing plate 111 that is positioned close to the side of the housing 10, and connects the L-shaped backing plate 113 and the fixing plate. 111 of the bent plate 112 .

The above is only a preferred embodiment of the utility model, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the utility model, some improvements and modifications can also be made, these improvements and Retouching should also be regarded as the scope of protection of the present utility model.

Claims (7)

1. a MGGH heat-exchange system, it is characterized in that: comprise the temperature rise heat exchanger (1) be set in turn on smoke discharge pipe, desulfurating dust-removing equipment (8) and cooling heat exchanger (2), pipeline connects the medium import (17) of temperature rise heat exchanger (1) and the media outlet (16) of cooling heat exchanger (2), and pipeline connects the media outlet (16) of temperature rise heat exchanger (1) and the medium import (17) of cooling heat exchanger (2), form the closed circulation of heat catalysis, closed circulation is provided with medium compensating tank (4), circulating pump (5) and medium heater (6), wherein, temperature rise heat exchanger (1) and cooling heat exchanger (2) include:

Housing (10), its upper and lower end is provided with fume inlet passage (14) and discharge flue (13), fume inlet passage (14) is by suction flange (141) and enter cigarette guide cylinder (142) and form, discharge flue (13) is made up of outlet(discharge) flange (131) and smoke evacuation guide cylinder (132), and the inwall entering cigarette guide cylinder (142) and smoke evacuation guide cylinder (132) is provided with leads cigarette gradient;

The header box (15) be communicated with housing (10), described medium import (17) and media outlet (16) are located at its two ends respectively;

And be positioned at the inner board-like heat exchange module (12) of housing (10), its one end is connected with header box (15), board-like heat exchange module (12) comprises and is severally parallel to the evenly distributed heat exchanger plates in smoke evacuation direction, the both sides of heat exchanger plates are respectively equipped with flue support protrusion (1213) and medium road support protrusion (1214), medium road support protrusion (1214) of adjacent heat exchanger plates leans or medium road support protrusion (1214) leans with the board plane of heat exchanger plates and is connected, form the heat catalysis folding Cheng Liudao of the sealing being communicated with medium import (17) and media outlet (16), heat catalysis folding Cheng Liudao comprises and severally has the pass partition (1211) that circumferential passageway (1212) and being arranged in circumferential passageway (1212) that standalone media imports and exports makes the heat catalysis circumferentially reciprocal folding Cheng Liudong of passage (1212), smoke evacuation once-through passage is formed between the flue support protrusion (1213) of adjacent heat exchanger plates.

2. a kind of MGGH heat-exchange system according to claim 1, it is characterized in that, temperature transmitter is equipped with in the discharge flue (13) of described temperature rise heat exchanger (1) and cooling heat exchanger (2), described medium heater (6) is also connected with heating electromagnetic valve (7), described closed circulation is also provided with and is communicated with the medium import (17) of cooling heat exchanger (2) and a bypass branch of media outlet (16), bypass branch is provided with bypass solenoid valve (3), temperature transmitter on described temperature rise heat exchanger (1) and heating electromagnetic valve (7) are electrically connected, temperature transmitter on described cooling heat exchanger (2) and bypass solenoid valve (3) are electrically connected.

3. a kind of MGGH heat-exchange system according to claim 1, it is characterized in that, described pass partition (1211) is at least one, the folding number of passes of described heat catalysis folding Cheng Liudao is even number, described header box (15) is positioned at housing (10) side, and its inside is provided with dividing plate (19), dividing plate (19) will completely cut off into the inlet distribution district be communicated with medium import (17) and the outlet doab be communicated with media outlet (16) in described header box (15).

4. a kind of MGGH heat-exchange system according to claim 1, it is characterized in that, described pass partition (1211) is at least one, the folding number of passes of described heat catalysis folding Cheng Liudao is odd number, and described header box (15) is made up of two housing parts (10) being positioned at housing (10) both sides.

5. according to a kind of MGGH heat-exchange system described in claim 1, it is characterized in that, described medium road support protrusion (1214) and flue support protrusion (1213) are for punching press ripple is protruding, weld muscle or plate muscle.

6. the board-like low-level (stack-gas) economizer of one according to any one of claim 1 to 5, is characterized in that, be provided with elastomer between the other end of described board-like heat exchange module (12) and housing (10), described elastomer is spring or rubber.

7. the board-like low-level (stack-gas) economizer of one according to any one of claim 1 to 5, it is characterized in that, be provided with flexible board (11) between the other end of described board-like heat exchange module (12) and housing (10), described flexible board (11) comprises one-body molded formation card and is against L shape backup plate (113) on board-like heat exchange module (12) end angle, is adjacent to the fixed head (111) of location and is connected the bending bent plate (112) of L shape backup plate (113) and fixed head (111) with housing (10) side.