JP6003448B2 - Steam generator - Google Patents

Description

  The present invention relates to a steam generator.

  Conventionally, boilers that boil fuel and boil water are widely used as steam generators. On the other hand, in order to be able to efficiently recover the energy of exhaust heat generated in factories and the like, a highly energy efficient steam generator that can generate steam without using fuel has been proposed (for example, , See Patent Document 1). According to the steam generator proposed in Patent Document 1, steam can be taken out from hot water having a relatively low temperature of about 90 ° C.

  As such a steam generator capable of taking out steam from hot water having a relatively low temperature, a shell and tube type steam / water separator including a tank and a tube arranged to penetrate the inside of the tank is provided. A steam generation apparatus using the above is also known. If a shell and tube type steam separator is used, for example, jacket cooling water (about 91 ° C.) of a gas engine is circulated through the tube as a heat source, and hot water of about 82 ° C. is sprayed on the tube inside the tank. Thus, it is possible to generate steam at the same time as the generator is driven by the gas engine. In this case, by forming a thin liquid film on the surface of the tube, steam can be generated even if the difference between the heat source circulating in the tube and the temperature of the sprayed water is relatively small at about 9 ° C. .

JP 2010-164223 A

  By the way, in such a shell-and-tube type steam separator, in order to generate steam efficiently, it is necessary to arrange many tubes inside the tank and increase the surface area of the tubes for heat exchange. There is. However, if the height of the tank is set high in order to place many tubes inside the tank, a lot of energy is needed to pump the water sprayed onto the tube up to the top of the tank, and the water is pumped up. The power consumed by the pump will increase.

  An object of this invention is to provide the steam generator which can improve energy efficiency more.

  The present invention includes a tank part, a tube extending in the horizontal direction inside the tank part, in which hot water serving as a heat source flows, a hot water supply line for supplying hot water to the tube, and hot water from the tube A hot water discharge line that discharges water, a spray nozzle that sprays water on the tube and is disposed above the tube inside the tank unit, and is provided in the upper part of the tank unit and is generated inside the tank unit A steam outlet for deriving the steam, a spray water supply line for supplying water stored in the lower part of the tank to the spray nozzle, and a spray water supply pump provided in the spray water supply line, The length of the tank part in the depth direction relates to a steam generator that is longer than the length of the tank part in the height direction.

  Moreover, it is preferable that the said tank part is comprised with several rectangular tanks whose length of the width direction is shorter than the length of the depth direction, and these tanks are connected with the width direction of this tank.

  The spray nozzles are arranged in a central region in the width direction of the tank at a predetermined interval in the depth direction of the tank, and the tubes extend in the depth direction of the tank and are arranged in the width direction of the tank. It is preferable that the number of the tubes arranged in a row and in the center portion in the width direction of the tank is larger than the number of tubes in the side portion in the width direction of the tank.

  The steam generator of the present invention performs heat exchange between a makeup water line that supplies makeup water to the tank unit, makeup water that flows through the makeup water line, and warm water that flows through the warm water discharge line. And a heat exchanger.

  The steam generator of the present invention further includes a check valve provided in the makeup water line, and the check valve blocks the flow of water to the upstream side of the makeup water line and has a predetermined pressure. It is preferable to allow supply of makeup water to the tank section through the makeup water line when receiving the above water pressure.

  Moreover, it is preferable that the steam generator of this invention is further equipped with the bypass line which connects the said warm water supply line and the said warm water discharge line.

  According to the present invention, since the electric power consumed by the pump for pumping the water stored in the lower part of the tank to the spray nozzle can be reduced, the energy efficiency of the entire steam generator can be further improved.

It is a figure which shows the outline of the steam generator which concerns on embodiment of this invention. It is a perspective view which shows the tank part (evaporation tank) in the steam generator which concerns on embodiment of this invention. It is sectional drawing of the tank part (evaporation tank) in the steam generator which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an outline of a steam generator according to an embodiment of the present invention.
The steam generator 1 of the present embodiment generates steam using a relatively low-temperature heat source such as exhaust heat of jacket cooling water of a gas engine. The steam generated in the steam generator 1 is compressed and sent to, for example, an exhaust heat recovery boiler.

  The steam generator 1 includes a tank unit 2, a steam outlet unit 24 provided in the tank unit 2, a spray nozzle 23 and a tube 25 disposed in the tank unit 2, a hot water supply line L1, and a hot water discharge line. L2, steam outlet line L3, spray water supply line L4, spray water supply pump 7 provided in spray water supply line L4, continuous blow line L5, concentration blow line L6, makeup water line L7, bypass The line L8 and the heat exchanger 3 are included. “Line” is a general term for lines capable of flowing fluid such as flow paths, paths, and pipelines.

The tank unit 2 is composed of a plurality of evaporation tanks 21 and generates steam. In the present embodiment, the tank unit 2 includes four evaporation tanks 21.
The steam outlet 24 is provided in the upper part of the tank unit 2. In the present embodiment, the vapor outlet 24 is provided on each of the plurality of evaporation tanks 21. The steam deriving unit 24 derives the steam generated in the tank unit 2.

The tube 25 extends in the horizontal direction inside the tank portion 2. Inside the tube 25, hot water serving as a heat source flows.
The spray nozzle 23 is disposed above the tube 25 inside the tank unit 2. The spray nozzle 23 sprays water toward the tube 25.
The tank part 2, the spray nozzle 23, and the tube 25 will be described in detail later.

  The hot water supply line L <b> 1 supplies hot water serving as a heat source to the tube 25. The upstream side of the hot water supply line L1 is connected to a gas engine or the like that supplies hot water serving as a heat source. The downstream side of the hot water supply line L <b> 1 is connected to one end of the tube 25.

  The hot water discharge line L2 circulates inside the tube 25 and discharges the hot water used as a heat source to the outside. The upstream side of the hot water discharge line L <b> 2 is connected to the other end of the tube 25.

  The steam lead-out line L3 leads the steam generated inside the tank unit 2. The upstream side of the steam outlet line L3 is connected to the steam outlet 24. The downstream side of the steam outlet line L3 is connected to an ejector, a steam compressor, etc. (not shown).

The spray water supply line L4 connects the lower part of the tank unit 2 and the spray nozzle 23, and supplies the water stored in the lower part of the tank unit 2 to the spray nozzle 23 as spray water. A spray water supply pump 7 is disposed in the spray water supply line L4.
The spray water supply pump 7 pumps the water stored in the lower part of the tank unit 2 to the spray nozzle 23.

  The continuous blow line L5 and the concentrated blow line L6 branch from the spray water supply line L4. Part of the water stored in the lower part of the tank unit 2 is drained by the continuous blow line L5 and the concentrated blow line L6. A valve 5 and a valve 6 are arranged in the continuous blow line L5 and the concentration blow line L6, respectively.

The makeup water line L7 connects the lower part of the tank unit 2 to a storage tank or the like that stores water. The makeup water line L7 supplies makeup water to the tank unit 2. A makeup water supply pump 8 and a check valve 9 are arranged in the makeup water line L7.
The makeup water supply pump 8 pressurizes water supplied from a storage tank or the like and supplies it to the inside of the tank unit 2. The check valve 9 blocks the flow of water to the upstream side of the make-up water line L7 and allows the make-up water line L7 to supply make-up water to the tank unit 2 when a water pressure higher than a predetermined pressure is received. To do.

  The bypass line L8 branches from each of the hot water supply line L1 and the hot water discharge line L2, and connects them. A valve 4 that is a three-way valve is disposed at a branch point from the hot water supply line L1 to the bypass line L8. By switching the valve 4, the supplied hot water can be discharged via the bypass line L 8 and the hot water discharge line L 2 without flowing through the tube 25 inside the tank unit 2.

  The heat exchanger 3 performs heat exchange between the hot water flowing through the hot water discharge line L2 and the water flowing through the makeup water line L7.

Next, the structure of the tank part 2, the vapor | steam derivation | leading-out part 24, the tube 25, and the spray nozzle 23 is demonstrated, referring FIG.2 and FIG.3.
FIG. 2 is a perspective view showing the tank unit 2 of the present embodiment. FIG. 3A shows the front surface of the evaporation tank 21 by cutting the evaporation tank 21 of FIG. 2 at a surface perpendicular to the depth direction and passing through a portion where the evaporation tank 21 and the spray water supply line L4 are connected. It is sectional drawing (sectional drawing of one evaporation tank 21) observed from the direction (X direction). FIG. 3B shows a cross section of the evaporation tank 21 observed at a central portion in the width direction of the evaporation tank 21 along a plane perpendicular to the width direction of the evaporation tank 21 and observed from the side surface direction (Y direction) of the evaporation tank 21. FIG.

  2 and 3, the tank portion 2 is formed in a rectangular parallelepiped shape in which the length (height) H1 in the height direction HD is shorter than the length (depth) L1 in the depth direction LD. In the present embodiment, the tank unit 2 includes a plurality of evaporation tanks 21 connected in the width direction WD. The plurality of evaporation tanks 21 are formed in a rectangular parallelepiped shape in which the length (width) W1 in the width direction WD is shorter than the length D1 in the depth direction LD.

  The vapor outlet 24 is provided in the central region in the width direction WD of the evaporation tank 21 and in the central region in the depth direction LD of the evaporation tank 21.

  The tubes 25 extend in the depth direction LD of the evaporation tank 21, are arranged in the width direction WD of the evaporation tank 21, and are further arranged in the height direction HD of the evaporation tank 21. Further, the interval W2 between the tubes 25 arranged at the center portion in the width direction WD of the evaporation tank 21 is narrower than the interval W3 between the tubes 25 arranged at the side portions in the width direction WD of the evaporation tank 21. That is, the number of tubes 25 arranged in the central portion of the evaporation tank 21 in the width direction WD is larger than the number of tubes 25 arranged in the side portions of the evaporation tank 21 in the width direction WD.

  The tube 25 present in the lower half of the evaporation tank 21 in the height direction HD is connected to the hot water supply line L1, and the tube 25 of the tube 25 present in the upper half of the evaporation tank 21 in the height direction HD is Connected to the hot water discharge line L2. The tube 25 existing in the lower half of the evaporating tank 21 in the height direction HD and the tube 25 existing in the upper half of the evaporating tank 21 in the height direction HD are connected to the inner side of the evaporating tank 21 in the depth direction LD. The hot water supplied from the supply line L1 circulates through the tube 25 existing in the lower half of the evaporating tank 21 in the height direction HD and then turns back to circulate through the tube 25 existing in the upper half of the evaporating tank 21 in the height direction HD. And is discharged by the hot water discharge line L2.

  A plurality of spray nozzles 23 are arranged in the center region in the width direction WD of the evaporation tank 21 with a predetermined interval in the depth direction LD of the evaporation tank 21. In the present embodiment, two spray nozzles 23 are arranged on the back side and the near side of the steam outlet 24. The spray angle of the spray nozzle 23 is wide and close to 180 °.

The steam generator 1 of this embodiment operates as follows.
First, hot water of about 91 ° C. serving as a heat source from a gas engine or the like is supplied to the tube 25 through the hot water supply line L1. The hot water supplied to the tube 25 flows through the tube 25 on the lower side in the height direction HD of the tank unit 2, and then flows through the tube 25 on the upper side in the height direction HD of the tank unit 2.
On the other hand, spray water is sprayed from the spray nozzle 23 toward the tube 25 inside the evaporation tank 21. Further, the inside of the evaporation tank 21 is maintained at a negative pressure (for example, -0.043 MPaG). As a result, the hot water flowing through the tube 25 is deprived of heat by the spray water, drops to about 84 ° C., and is discharged through the hot water discharge line L2.

  In addition, a thin liquid film is formed on the surface of the tube 25 through which warm water flows by spraying water at about 82 ° C. from the spray nozzle 23. Thus, in a state where the negative pressure is maintained, a thin liquid film is formed on the surface of the tube 25, so that the temperature difference between the hot water flowing through the tube 25 and the water sprayed by the spray nozzle 23 is increased. Even when it is relatively small (for example, about 9 ° C.), steam can be generated efficiently.

  Since water sprayed from the spray nozzle 23 evaporates on the surface of the tube 25, the liquid film on the surface of the tube 25 becomes thinner as the tube 25 on the lower side in the height direction HD of the tank portion 2. As described above, if the hot water is circulated through the tube on the lower side in the height direction HD of the tank unit 2 and then the tube on the upper side in the height direction HD of the tank unit 2 is circulated, As the tube 25 circulates, the liquid film on the surface of the tube 25 becomes thinner. Since the steam generation efficiency of the entire steam generator tends to be higher when heat exchange between the hot water and the liquid film water is performed at the thin portion of the liquid film on the surface of the tube 25, Warm water serving as a heat source is circulated in the order from the lower tube 25 to the upper tube 25 in the vertical direction HD.

  The steam generated inside the evaporation tank 21 is led out from the steam lead-out unit 24 and supplied to an ejector, a steam compressor, and the like through the steam lead-out line L3.

  Water that has not become steam inside the evaporation tank 21 is stored in the lower part of the evaporation tank 21. The water stored in the lower part of the evaporation tank 21 is pumped up to the spray nozzle 23 by the spray water supply pump 7 through the spray water supply line L4 and sprayed on the tube 25 again.

  The continuous blow line L5 and the concentrated blow line L6 branched from the spray water supply line L4 drain the water stored in the evaporation tank 21. Since the water stored in the evaporation tank 21 circulates between the spray water supply line L4 and the tank unit 2, if this circulation is continued, the water stored in the tank unit 2 will be stored in the tank unit 2. It decreases by the amount of vapor generated in, and the concentration of harmful ions such as chloride ions increases. In order to avoid the risk of corrosion and failure of the steam generator due to excessive concentration of circulating water, the circulating water is discharged by the continuous blow line L5 and the concentrated blow line L6. The continuous blow line L5 and the concentration blow line L6 are provided with a valve 5 and a valve 6, respectively. The continuous blow line L5 always discharges a fixed amount of water by opening the valve 5, or discharges a fixed amount of water every fixed time. The concentration blow line L6 monitors the concentration value of chloride ions etc. of the water stored in the tank unit 2, and when the value exceeds a certain standard, the valve 6 is opened and a certain amount of water is discharged. .

  When the amount of water that circulates between the spray water supply line L4 and the tank unit 2 decreases, the makeup water is replenished to the evaporation tank 21 from the makeup water line L7. The water replenished by the replenishing water line L7 exchanges heat with the hot water flowing through the warm water discharge line L2 by the heat exchanger 3. The water supplied by the makeup water line L7 is heated to, for example, about 40 ° C. by exchanging heat with the warm water flowing through the warm water discharge line L2.

  In addition, the water flow to the upstream side of the make-up water line L7 is interrupted, and the supply of make-up water to the tank unit 2 by the make-up water line L7 when the water pressure exceeds a predetermined pressure is provided. By providing the check valve 9 in the makeup water line L7, it is possible to prevent the makeup water from flowing into the tank section 2 immediately after the steam generator 1 is stopped. In other words, when the steam generator 1 is in operation, the inside of the tank unit 2 is at a negative pressure, and immediately after the steam generator 1 is stopped, a force for the makeup water to flow into the tank works. Since the valve 9 needs a certain amount of pressure to allow water to flow in the forward direction (tank part 2 side), the replenishment water does not flow into the tank part 2 side as long as the inside of the tank part 2 is slightly negative. .

  Furthermore, the steam generator 1 includes a bypass line L8. When some trouble occurs in peripheral equipment such as a steam compressor connected downstream of the steam outlet line L3, if hot water continues to flow through the tube 25 in the evaporation tank 21, the temperature in the evaporation tank 21 is Undesirable and excessive amounts of steam are generated. In the case of such trouble with peripheral devices, the hot water is not circulated through the tube 25 in the evaporation tank 21, but the hot water is circulated through the bypass line L8 by switching the valve 4, thereby generating an excessive amount of steam. Can be prevented. In addition, by using the bypass line L8 instead of stopping the power supply of the entire steam generator 1, the water level stored in the tank unit 2 and the water temperature are not lowered, and the peripheral equipment is troubled. It is possible to speed up the start of steam generation even when the plant is restored.

The steam generator 1 according to the present embodiment has the following effects.
(1) The length D1 of the tank part 2 in the depth direction LD is longer than the length H1 of the tank part 2 in the height direction HD. Thereby, the energy for pumping the spray water stored in the lower part of the tank part 2 (evaporation tank 21) to the spray nozzle by the spray water supply pump 7 can be suppressed, and the power consumption by the spray water supply pump 7 is saved. be able to. Moreover, if the height of the tank part 2 is lowered, the number of tubes that can be arranged in the tank part 2 is reduced and the amount of steam generated is reduced. However, the length of the tank part 2 in the depth direction is reduced. By increasing the length, the length of the tube is increased so that the amount of steam generated does not decrease. In this way, the energy efficiency of the entire steam generator 1 can be further improved without reducing the steam generation efficiency.

  (2) The tank unit 2 is configured by a plurality of evaporation tanks 21 having a length W1 in the width direction WD shorter than a length D1 in the depth direction LD, and the plurality of evaporation tanks 21 in the width direction WD of the evaporation tank 21. Connected. If the tank unit 2 is composed of a single large tank, a plate thickness for pressure resistance is required, which increases the cost of manufacturing the tank, and requires a large tank installation notification and performance inspection. However, in the steam generator 1 of the present embodiment, such a problem can be avoided. In other words, it is possible to manufacture the evaporation tank 21 with a thin plate thickness, thereby reducing the cost. In addition, if the evaporation tank 21 is set within the standard of a small pressure vessel, management costs such as installation notification and performance inspection are also required. Can be reduced. Furthermore, the steam generation capability of the steam generator 1 can be easily changed by appropriately changing the number of the plurality of evaporation tanks 21 arranged.

  (3) A plurality of spray nozzles 23 are arranged in the central region of the evaporation tank 21 in the width direction WD with a predetermined interval in the depth direction LD of the evaporation tank 21, and the tube 25 is extended in the depth direction LD of the evaporation tank 21, A plurality of rows are arranged in the width direction WD of the evaporation tank 21, and the number of the tubes 25 in the central portion of the evaporation tank 21 in the width direction WD is larger than the number of the tubes 25 in the side portion of the evaporation tank 21 in the width direction WD. The configuration. Even if the spray angle of the spray nozzle 23 is wide, the central portion of the evaporation tank 21 in the width direction WD has more water to be sprayed than the side portion. By disposing more tubes 25 at the center of the WD than at the sides, a liquid film can be uniformly formed on the surface of the tubes 25, and the steam generation efficiency of the steam generator 1 is increased. This is possible.

  (4) By providing the heat exchanger 3 that performs heat exchange between the hot water flowing through the hot water discharge line L2 and the make-up water flowing through the make-up water line L7, the temperature of the make-up water supplied to the tank unit 2 is set. It can be raised in advance, and the steam generation efficiency of the steam generator 1 can be increased.

  (5) A function of interrupting the flow of water to the upstream side of the makeup water line L7 and allowing the makeup water line L7 to supply makeup water to the tank unit 2 when a water pressure higher than a predetermined pressure is received. By providing the check valve 9 provided, it is possible to prevent the makeup water from flowing into the tank unit 2 immediately after the steam generator 1 is stopped. That is, since the inside of the tank unit 2 (evaporation tank 21) is at a negative pressure when the steam generator 1 is in operation, the force for the makeup water to flow into the tank side immediately after the steam generator 1 is stopped. However, since the check valve 9 requires a certain amount of pressure for the water to flow in the forward direction (tank part 2 side), the makeup water is supplied to the tank part to the extent that the inside of the tank part 2 is slightly negative. Does not flow into side 2.

  (6) The steam generator 1 includes a bypass line L8. When some trouble occurs in peripheral equipment such as a steam compressor connected downstream of the steam outlet line L3, if hot water continues to flow through the tube 25 in the evaporation tank 21, the temperature in the evaporation tank 21 is Undesirable and excessive amounts of steam are generated. In the case of such trouble with peripheral devices, the hot water is not circulated through the tube 25 in the evaporation tank 21, but the hot water is circulated through the bypass line L8 by switching the valve 4, thereby generating an excessive amount of steam. Can be prevented. In addition, by using the bypass line L8 instead of stopping the power supply of the entire steam generator 1, the water level stored in the tank unit 2 and the water temperature are not lowered, and the peripheral equipment is troubled. It is possible to speed up the start of steam generation even when the plant is restored.

  The preferred embodiment of the steam generator of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and can be modified as appropriate.

DESCRIPTION OF SYMBOLS 1 Steam generator 2 Tank part 3 Heat exchanger 4, 5, 6 Valve 7 Spray water supply pump 8 Makeup water supply pump 9 Check valve 21 Evaporating tank 23 Spray nozzle 24 Steam outlet 25 Tube L1 Hot water supply line L2 Hot water discharge Line L3 Steam outlet line L4 Spray water supply line L5 Continuous blow line L6 Concentrated blow line L7 Make-up water line L8 Bypass line

Claims (6)

A tank section,
A plurality of tubes arranged in the tank portion so as to extend in the horizontal direction, and in which hot water serving as a heat source circulates,
A hot water supply line for supplying hot water to the tube existing in the lower half of the tank in the height direction ;
A hot water discharge line for discharging hot water from the tube present in the upper half of the tank portion in the height direction ;
A spray nozzle that is disposed above the tube inside the tank portion and sprays water on the tube;
A steam outlet portion provided at an upper portion of the tank portion, for leading out steam generated inside the tank portion;
A spray water supply line for supplying water stored in the lower part of the tank part to the spray nozzle;
A spray water supply pump provided in the spray water supply line,
The length of the tank part in the depth direction is a steam generator longer than the length of the tank part in the height direction. The tank portion is constituted by a plurality of rectangular parallelepiped tanks whose length in the width direction is shorter than the length in the depth direction,
The steam generator according to claim 1, wherein the plurality of tanks are connected in a width direction of the tanks. A plurality of the spray nozzles are arranged at predetermined intervals in the depth direction of the tank in the central region in the width direction of the tank,
The tubes extend in the depth direction of the tank and are arranged in a plurality of rows in the width direction of the tank,
The steam generator according to claim 2, wherein the number of the tubes in the central portion in the width direction of the tank is larger than the number of the tubes in the side portions in the width direction of the tank. A makeup water line for supplying makeup water to the tank section;
The steam generator according to any one of claims 1 to 3, further comprising: a heat exchanger that exchanges heat between makeup water flowing through the makeup water line and warm water flowing through the warm water discharge line. A check valve provided in the makeup water line;
The check valve blocks the flow of water to the upstream side of the make-up water line, and allows supply of make-up water to the tank section by the make-up water line when a water pressure higher than a predetermined pressure is received. The steam generator according to claim 4. The steam generator according to any one of claims 1 to 5, further comprising a bypass line connecting the hot water supply line and the hot water discharge line.

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