JP2014074502A - Hot water generating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water generating device capable of preventing temperature of hot water from being decreased to be less than a set temperature when a flow rate of cold water having passed through a cold water inlet pipe is decreased and further capable of preventing temperature of hot water from being increased to be more than a set temperature when a taking-out rate of hot water having passed through a hot water outlet pipe is decreased.SOLUTION: A corrugated spiral tube type heat exchanger 1 has a shell of several spiral tubes to which a cold water inlet pipe 4, a hot water outlet pipe 5, a steam supply pipe 2 and a drain discharge pipe 3 are connected to flow water. A cylindrical diversion member 46 with a bottom part is arranged at the several spiral tubes where the cold water inlet pipe 4 is connected, an outer passage 47 communicating the cold water inlet pipe 4 with outsides of the several spiral tubes is arranged outside the circumference wall of the diversion member 46 and a peripheral wall of the diversion member 46 is provided with a communication passage 48 communicating with inside and outside portions and having a passage area smaller than that of the outer passage.

Description

The present invention relates to a hot water generator that generates hot water by heating cold water with the heat of steam.

A conventional hot water generator is disclosed in, for example, Japanese Patent Application Laid-Open No. 2010-25394. In this structure, a cold water intake pipe and a hot water discharge pipe communicating with a plurality of spiral tubes of a corrugated spiral tube heat exchanger are connected, and a steam supply pipe and a drain discharge pipe communicating with a shell are connected.

JP 2010-25394 A

In the conventional hot water generator, when the flow rate of cold water from the cold water intake pipe decreases, the flow rate of cold water in the spiral tubes decreases, the heat exchange efficiency between cold water and steam decreases, and the hot water decreases below the set temperature. There was a problem to do.

Therefore, the problem to be solved by the present invention is to provide a hot water generating device that can prevent the hot water from dropping below a preset temperature when the flow rate of cold water from the cold water intake pipe is reduced.

In order to solve the above-mentioned problems, a hot water generator of the present invention is a steam supply pipe that connects a cold water intake pipe and a hot water discharge pipe that communicate with a plurality of spiral tubes of a corrugated spiral tube heat exchanger and communicates with a shell. And a drain discharge pipe are connected, a bottomed cylindrical diversion member is arranged on the cold water intake pipe side of the plurality of spiral tubes, and the cold water intake pipe side and the outer sides of the plurality of spiral tubes are arranged outside the peripheral wall of the diversion member. The present invention is characterized in that an outer passage that communicates with the arrangement side is provided and a communication passage that communicates the inside and the outside with a peripheral wall of the flow dividing member and that has a smaller flow area than the flow area of the outer passage is provided.

According to the present invention, when the chilled water flow rate from the chilled water intake pipe decreases, the chilled water is supplied only to the outer side of some of the spiral tubes through the outer passage outside the peripheral wall of the flow dividing member. Since it is possible to prevent a decrease in the efficiency of heat exchange between cold water and steam due to a decrease in the flow rate, there is an effect that it is possible to prevent the hot water from decreasing below a set temperature.

Sectional drawing of the hot water production | generation apparatus concerning embodiment of this invention. Sectional drawing of the flow-dividing member part of FIG.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2. The cold water intake pipe 4 and the hot water extraction pipe 5 communicating with the plurality of spiral tubes of the corrugated spiral tube heat exchanger 1 are connected, and the steam supply pipe 2 and the drain discharge pipe 3 communicating with the shell are connected. An on-off valve 6, a gas-liquid separator 7, an electric valve 8 as an operation valve, a safety valve 9, and a control valve 10 are attached to the steam supply pipe 2 from the upstream side. A header tank 11 is connected to the drain discharge pipe 3. The header tank 11 temporarily stores the drain discharged from the heat exchanger 1. A drain inflow pipe 12 is connected to the header tank 11, and a check valve 13 and a drain pressure feed pump 14 are attached to the drain inflow pipe 12 from the upstream side. The check valve 13 allows passage of fluid from the header tank 11 to the drain pressure feed pump 14 and prevents passage in the opposite direction.

The drain pressure pump 14 has a drain inlet 15, a drain pressure inlet 16, a steam inlet 17, and a steam outlet 18. A drain inlet pipe 12 is connected to the drain inlet 15 via a check valve 13. A drain pressure feed pipe 19 is connected to the drain pressure feed port 16, and a check valve 20 and an opening / closing valve 21 are attached to the drain pressure feed pipe 19 from the upstream side. The check valve 20 allows passage of fluid from the drain pumping pump 14 to the on-off valve 21 and prevents passage in the opposite direction. A steam introduction pipe 22 branched from the steam supply pipe 2 is connected to the steam introduction port 17, and an opening / closing valve 23, a strainer 24, and a pressure reducing valve 25 are connected to the steam introduction pipe 22 from the upstream side. A pressure gauge 26 and a pressure gauge 27 are provided before and after the pressure reducing valve 25 of the steam introduction pipe 22. A drain evacuation pipe 28 branched from a connection portion of the steam introduction pipe 22 to the steam introduction port 17 is connected to the drain pressure feed pipe 19, and a steam trap 29 and a check valve 30 are attached to the drain evacuation pipe 28 from the upstream side. The steam trap 29 automatically discharges drain to the downstream check valve 30 side without discharging steam. The check valve 30 allows passage of fluid from the steam trap 29 to the drain pressure feed pipe 19 and prevents passage in the opposite direction. The steam discharge port 18 is connected to the upstream side of the exhaust valve 34 of the initial air discharge pipe 33 described below by an exhaust pipe 43.

When the float (not shown) disposed inside is located at the lower part, the drain pressure feed pump 14 closes the steam introduction port 17 and opens the steam discharge port 18, and drains accumulated in the header tank 11 through the check valve 13. Through the drain inlet 15. When drain is accumulated inside and a float (not shown) is located at a predetermined upper portion, the steam discharge port 18 is closed, the steam introduction port 17 is opened, and the steam in the steam introduction pipe 22 is introduced from the steam introduction port 17 to the inside. By letting it flow in, the drain accumulated inside is pumped from the drain pumping port 16 to the desired pumping destination through the drain pumping pipe 19. When the liquid level inside falls due to the pumping of the drain, the steam inlet 17 is closed again, the steam outlet 18 is opened, and the drain flows down from the drain inlet 15 to the inside. By repeating such an operation cycle, the drain pumping pump 14 pumps the drain from the header tank 11 to a desired pumping destination.

A drain discharge port 31 of the gas-liquid separator 7 is connected between a steam trap 29 of the drain removal pipe 28 and the check valve 30 by a drain removal pipe 32. An initial air discharge pipe 33 branched from the drain discharge pipe 3 is connected to the drain exclusion pipe 32. An exhaust valve 34 and a check valve 35 are attached to the initial air discharge pipe 33. The exhaust valve 34 exhausts the initial air of the header tank 11. The check valve 35 allows passage of fluid from the exhaust valve 34 to the drain exclusion pipe 32 and prevents passage in the opposite direction. A flow switch 36 is provided in the cold water intake pipe 4. A temperature sensor 37 is provided in the hot water outlet pipe 5, and an open / close valve 38 is attached to the hot water usage destination. A cold water reservoir 42 is provided on the cold water intake pipe 4 side of the heat exchanger 1. The cold water reservoir 42 can be formed integrally with the heat exchanger 1 or provided between the heat exchanger 1 and the cold water intake pipe 4 separately from the heat exchanger 1. On the cold water intake pipe 4 side of the plurality of spiral tubes of the heat exchanger 1, a bottomed cylindrical flow dividing member 46 having a lower end fixed by welding via a plurality of ribs 45 is disposed at the lower end of the outer cylindrical member 44. The outer cylindrical member 44 and the flow dividing member 46 are disposed between the spiral tube side flange and the cold water reservoir side flange, and are sandwiched by fastening means including bolts and nuts (not shown). An annular outer passage 47 that communicates the cold water intake pipe 4 side and the outer side of the plurality of spiral tubes is provided outside the peripheral wall of the flow dividing member 46, and the flow passage area is communicated with the peripheral wall of the flow dividing member 46 from the inside to the outside. A communication passage 48 smaller than the flow path area of the outer passage 47 is provided.

Usually, the cold water from the cold water intake pipe 4 is supplied to the outer side of a part of the plurality of spiral tubes through the outer passage 47 outside the peripheral wall of the flow dividing member 46, and the plurality of spirals from the outer passage 47 through the communication passage 48. It is supplied to the inner arrangement side of the other part of the tube. When the chilled water flow rate from the chilled water intake pipe 4 decreases, the chilled water flow rate is decreased by supplying the chilled water only to the outer side of some of the plurality of spiral tubes through the outer passage 47 outside the peripheral wall of the flow dividing member 46. It is possible to prevent the heat exchange efficiency between the cold water and the steam from decreasing due to the hot water, and the hot water can be prevented from decreasing below the set temperature. The opening of the control valve 10 is reduced when the temperature of the hot water detected by the temperature sensor 37 is higher than the set temperature, and is increased when the temperature is lower than the set temperature. The motor-operated valve 8 as the operation valve is closed when the temperature of the hot water detected by the temperature sensor 37 rises by a predetermined temperature below the set temperature due to the control range of the control valve 10 or less or due to a failure of the control valve 10. The motor-operated valve 8 as the operation valve is set to the temperature of the hot water detected by the temperature sensor 37 when the flow of the cold water is not detected by the flow switch 36 or when the flow switch 36 is not detected. It is closed when a predetermined temperature rises above the temperature. When the removal of the hot water is stopped and the flow of cold water is no longer detected by the flow switch 36, the motor-operated valve 8 can be closed early by closing the motor-operated valve 8 as the operation valve. When the extraction of the water is resumed, the relatively low temperature hot water can be extracted.

INDUSTRIAL APPLICATION This invention can be utilized for the warm water production | generation apparatus which produces | generates warm water by heating cold water with the heat of steam.

DESCRIPTION OF SYMBOLS 1 Corrugated spiral tube type heat exchanger 2 Steam supply pipe 3 Drain discharge pipe 4 Chilled water intake pipe 5 Hot water discharge pipe 6 On-off valve 7 Gas-liquid separator 8 Motor operated valve 9 Safety valve 10 Control valve 11 Header tank 12 Drain inflow Pipe 13 Check valve 14 Drain pressure feed pump 15 Drain inlet 16 Drain pressure feed port 17 Steam inlet 18 Steam outlet 19 Drain pressure feed pipe 20 Check valve 21 Open / close valve 22 Steam inlet pipe 23 Open / close valve 24 Strainer 25 Pressure reducing valve 26 Pressure Total 27 Pressure gauge 28 Drain evacuation pipe 29 Steam trap 30 Check valve 31 Drain discharge port 32 Drain evacuation pipe 33 Initial air discharge pipe 34 Exhaust valve 35 Check valve 36 Flow switch 37 Temperature sensor 38 On-off valve 42 Cold water reservoir 43 Exhaust Pipe 44 Outer cylindrical member 45 Rib 46 Flow diverting member 47 Outer passage 48 Communication passage

Claims (1)

In a corrugated spiral tube heat exchanger, a cold water intake pipe and a hot water discharge pipe connected to a plurality of spiral tubes and a steam supply pipe and a drain discharge pipe connected to a shell are connected. A cylindrical shunt member with a bottom is arranged on the inlet pipe side, and an outer passage that communicates the cold water intake pipe side with the outer side of the spiral tubes is provided outside the peripheral wall of the shunt member, and on the peripheral wall of the shunt member A hot water generating apparatus characterized in that a communication passage is provided which communicates the inside and outside and has a flow passage area smaller than the flow passage area of the outer passage.

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