JP2002130993A - Method and apparatus for discharging refuse in shell and tube type heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically discharge refuse grown into a large size in a water chamber from the chamber. SOLUTION: A shell and tube type heat exchanger is adapted such that drain water 1 is assumed an actuation fluid and heat exchange is performed between the actuation fluid and another heat medium. To water chambers A, B, and C located at opposite ends of a fine tube 8 of the foregoing heat exchanger forced discharge drain tubes 11a, 11b, and 11c are connected anew independently from a system of the actuation fluid, and in the course of these drain tubes 11a, 11b, and 11c there are provided discharge valves 9a, 9b, and 9c capable of remote control, which are in turn opened upon cleaning top discharge refuse accumulated in the respective water chambers A, B, and C to the outside of a system of the actuation fluid through the respective drain tubes 11a, 11b, and 11c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shell-and-tube heat exchanger that uses waste water as a working fluid and exchanges heat between the working fluid and another heat medium.
The present invention relates to a method and an apparatus for discharging dust accumulated in water chambers at both ends of a thin tube of a heat exchanger.

[0002]

2. Description of the Related Art Conventionally, bathrooms of accommodation facilities and apartment houses,
Shell-and-water that exchanges heat between this working fluid and another heat medium (for example, a heat medium of a heat pump) is used as working fluid, such as domestic wastewater discharged from a kitchen, a washroom, or wastewater discharged from a heated pool or a sauna bath. Tube heat exchangers are known.

In such a shell and tube heat exchanger, a plurality of thin tubes are generally arranged in parallel, water chambers are provided at both ends thereof, and a water chamber on one side is formed as a counterflow water chamber, and the other is formed as a counterflow water chamber. The water chamber on the side is divided into two chambers. Then, the drainage pumped from the drainage tank was introduced into one of the water chambers on the defined side, passed through the narrow tube connected thereto, and the flow direction of the drainage was reversed in the countercurrent water chamber to define this. It is guided into a narrow tube connected to the other water chamber on the side, and is discharged to the drainage tank through the other water chamber. In other words, the thin tube, which is a portion that exchanges heat with another heat medium, is configured as a staggered pipe having the reverse flow water chamber as an inversion portion, so that the length of the thin tube is substantially increased.

[0004]

However, in such a shell and tube type heat exchanger using the waste water as a working fluid, the waste water contains dirt (impurities). Although various filters and strainers are installed to remove impurities, the impurities (especially, slender objects such as hair and fibers) could not be completely removed.

[0005] In order to remove impurities that are necessarily mixed in, there has been proposed a method in which the flow direction of the drainage in the main pipe is forcibly switched to the opposite direction at the time of cleaning to discharge the impurities. In the water chambers at both ends of the thin tube, it grows gradually while entangled with hair, fibers and the like as nuclei, and in several hours it becomes larger than a fist size, and eventually closes the inlet of the thin tube. Such a phenomenon of the growth of impurities is remarkable in the countercurrent water chamber, which is a folded portion of the thin tube in the middle of the heat exchanger, and it cannot be discharged even if the flow direction of the drainage in the main pipe is changed. In such a state, the function of the heat exchanger could not be fulfilled, and the water chamber had to be manually opened to remove dust.

The technical problem of the present invention is to grow in a water chamber,
The purpose of the present invention is to make it possible to automatically discharge garbage that has grown up from the water chamber.

[0007]

According to a first aspect of the present invention, there is provided a method for discharging refuse in a shell and tube type heat exchanger.
Drains for forced discharge are provided separately from the working fluid system in the water chambers at both ends of the shell and tube heat exchanger, which uses the waste water as the working fluid and performs heat exchange between this working fluid and another heat medium. Newly connected pipes, remote controllable drain valves are provided in the middle of these drain pipes, and these drain valves are opened during cleaning, and the refuse accumulated in each water chamber is discharged from each drain pipe to the outside of the working fluid system. It is characterized by doing.

The apparatus according to claim 6 used in this method is characterized in that the waste water is used as a working fluid, and heat is exchanged between the working fluid and another heat medium. Drain pipes for forced discharge are newly connected to the water chamber separately from the working fluid system.Discharge valves that can be remotely operated are provided in the middle of these drain pipes, and control for opening and closing these discharge valves during cleaning is performed. A device is provided.

According to a second aspect of the present invention, there is provided a method for discharging dust in a shell-and-tube heat exchanger, wherein the flow direction of the working fluid is switched between forward and reverse while the discharge valve is open, so that forward flow and reverse flow are repeated. It is characterized by:

According to a seventh aspect of the present invention, there is provided an apparatus according to a seventh aspect, wherein a remotely controllable forward / reverse switching valve for switching a flow direction of the working fluid in a forward / reverse direction is provided in the working fluid system. The forward / reverse switching valve is operated while the discharge valve is open, so that the forward and reverse flows of the working fluid are repeated.

According to a third aspect of the present invention, there is provided a method for discharging dust in a shell-and-tube heat exchanger, wherein a cleaning operation is performed at every predetermined operation time.

The apparatus according to claim 8 used in this method is such that the control device is set so as to perform the cleaning operation every predetermined operation time.

According to a fourth aspect of the present invention, there is provided a method for discharging dust in a shell-and-tube heat exchanger, wherein a cleaning operation is performed when a fluid pressure in a working fluid system exceeds a predetermined value. .

According to a ninth aspect of the present invention, a pressure gauge is provided in the system of the working fluid, and the control device causes the cleaning operation to be performed when the fluid pressure in the system exceeds a predetermined value. It is set as follows.

According to a fifth aspect of the present invention, in the method for discharging dust in the shell-and-tube heat exchanger, the cleaning operation is performed at every predetermined operation time, and the fluid pressure in the working fluid system exceeds a predetermined value. It is characterized in that it is also performed in the case.

According to a tenth aspect of the present invention, a pressure gauge is provided in a system of a working fluid, and the control device comprises:
The cleaning operation is performed every predetermined operation time, and the cleaning operation is performed even when the fluid pressure in the working fluid system exceeds a predetermined value.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for discharging dust from a shell and tube type heat exchanger according to an embodiment of the present invention and an apparatus used for the method will be described below with reference to FIGS. FIG. 1 is a configuration diagram illustrating a dust discharge device in a shell and tube type heat exchanger according to the present embodiment, FIG. 2 is a block diagram illustrating a configuration of a control device unit, and FIG. 3 and FIG. is there.

As shown in FIG. 1, the refuse discharge device in the shell and tube type heat exchanger of the present embodiment is a household wastewater discharged from a bathroom, a kitchen, a washroom or the like of an accommodation facility or an apartment house, a heated pool or a sauna bath. 1 is taken out of a drain tank 2 by a pump 3 and supplied as a working fluid to a heat exchanger 4 where the heat is exchanged with another heat medium (for example, a heat medium of a heat pump). , Heat exchange is performed, and the waste water 1 that has become cold water is discharged to the drain tank 2 again.

The main pipe 5 constituting the working fluid system includes a water intake pipe 5a provided with a pump 3 on the way and having one end extending below the water surface of the drainage tank 2, and a T-shape at the other end of the water intake pipe 5a. The branch pipes 5b and 5c are connected to each other, and the ends thereof are connected to both ends of a flow path in the heat exchanger. The branch pipes 5b and 5c are connected to the branch pipes 5b and 5c via forward / reverse switching valves 6a and 6b. The discharge pipes 7a and 7b are connected to each other, and the other ends of the discharge pipes 7a and 7b extend above the water surface of the drainage tank 2.

Each of the forward / reverse switching valves 6a and 6b switches the flow direction of the working fluid in the forward / reverse direction. For example, one forward / reverse switching valve 6a sets the flow direction of the working fluid in the direction of the heat exchanger 4. When the heat exchanger 4 is operated, the other forward / reverse switching valve 6b is connected to the heat exchanger 4 with respect to the supply side and the discharge side of the working fluid so that the working fluid flows from the heat exchanger 4 toward the discharge pipe 7b. It is set to switch at the same time. Here, the working fluid is supplied to the heat exchanger 4 through the branch pipe 5b on the side of the forward / reverse switching valve 6a, and is discharged from the heat exchanger 4 through the branch pipe 5c on the side of the forward / reverse switching valve 6b. The flow in the direction flowing in the opposite direction is defined as the normal flow direction, and the flow in the opposite direction is defined as the reverse direction.

The heat exchanger 4 has a plurality of thin tubes 8 arranged side by side, water chambers provided at both ends thereof, a water chamber on one side is formed as a counterflow water chamber B, and a water chamber on the other side is 2 Each of the small tubes 8 is formed in a staggered pipe having the counterflow water chamber B as an inversion section. The branch pipe 5b is provided in the water chamber A which is one end of the flow path in the heat exchanger, and the branch pipe 5b is similarly provided in the water chamber C which is the other end of the flow path in the heat exchanger.
c are connected to each other.

In each of the water chambers A, B, and C, one end of a drain pipe 11a, 11b, 11c for forced discharge having a discharge valve 9a, 9b, 9c which can be remotely operated on the way is provided with the above-mentioned working flow. It is newly connected separately from the system and discharges refuse out of the system.

In the working fluid system, here, each branch pipe 5b,
Pressure gauges 12a and 12b are provided in the vicinity of the connection with the heat exchanger 4 of 5c, respectively.
The output signal 2b is input to the control device 13 which controls the entire system.

As shown in FIG. 2, the control device 13
The comparator 14 compares the water chamber pressure P detected by 2a and 12b with the set value, and integrates the operation time by receiving the comparison result of the comparator 14 or the operation state signal of the pump 3 from the pump control means 15. Looking at the operation time from the operation time counter 16, it is determined whether or not to perform cleaning. When the water chamber pressure, that is, the fluid pressure P in the working fluid system exceeds a predetermined value, or when the operation time elapses a predetermined time, A cleaning start signal is output, and when an end signal is input, a cleaning determination unit 17 that resets the operation time counter 16 is input. When a cleaning start signal is output from the cleaning determination unit 17, this is input and each of the discharge valves 9a, 9b and 9c are opened simultaneously or sequentially, and when an end signal is input, each discharge valve 9a, 9b, 9c is opened.
Discharge valve control means 18 for simultaneously or sequentially closing
When a washing start signal is output from the washing determining means 17, the washing start signal is input, and a reverse flow signal and a normal flow signal are alternately output according to a sequence program and a set number of forward / reverse switching is performed. , A reset signal is output, and the cleaning determination means 17 and the discharge valve control means 18 are output.
Main channel switching means 19 for notifying the user that cleaning has been completed
When the backflow signal is input from the main pipe flow switching means 19, the forward / reverse switching valves 6a and 6b are simultaneously switched so that the flow direction of the working fluid in the main pipe 5 becomes the reverse flow direction. When a forward flow signal is input from the flow path switching means 19, the forward / reverse switching valves 6a and 6b are simultaneously switched so that the flow direction of the working fluid in the main pipe 5 becomes the forward flow direction. Switching device control means 21 for outputting a switching signal when switching to the control mode, and receiving the switching signal from the switching valve control means 21 to count the number of times of switching, and forward / reverse switching times K to the main channel switching means 19 When the reset signal is input from the main channel switching means 19, the switching counter 22 returns to the initial state.

Next, a method of discharging waste by the shell and tube type heat exchanger of the present embodiment will be described based on FIGS. 3 and 4 and with reference to FIGS. In addition,
Here, it is assumed that the heat exchanger is operated and is in a normal operating state, that is, a state in which the working fluid continuously flows in the positive flow direction, and is performing heat exchange with, for example, a heat medium of a heat pump.

First, as shown in FIG. 3, the pressure P in both ends of the flow path in the heat exchanger, that is, in the water chambers A and B is checked (step 1).
11) It is determined whether or not the pressure P in the water chamber has exceeded the set value (step 112). If the pressure P in the water chamber has not exceeded the set value, the operation time is examined next (step 113), and the operation time is set. It is determined whether or not the time has elapsed (step 114), and if the operating time has not exceeded the set time, the process is terminated. If it is determined in step 112 that the water chamber pressure P has exceeded the set value, or if it is determined in step 114 that the operating time has exceeded the set time, the process jumps to step 115 to perform the cleaning process. ,
Thereafter, the operation time counter 16 is reset (step 116), and the process ends.

The cleaning process is performed as shown in FIG.
First, drain pipes 11a, 11b, 1 of water chambers A, B, C
The discharge valves 9a, 9b, 9c of 1c are opened simultaneously or sequentially (step 211). Next, each forward / reverse switching valve 6a,
6b is switched to the reverse flow direction (step 212), and the drainage in the main pipe is caused to flow backward for a predetermined time (here, 30 seconds). When this backflow state has elapsed for 30 seconds (step 213), each of the forward / reverse switching valves 6a and 6b is switched to the forward flow direction (step 214), and the drainage in the main pipe is allowed to flow forward for a predetermined time (here, 20 seconds). Let it. If this normal flow state has elapsed for 20 seconds (step 215), the number of forward / reverse switching K is counted (step 216), and it is determined whether or not the number of forward / reverse switching K is a set number of times (step 217). If the number of times K is not the set number of times, the process returns to step 212, and step 212
Steps 216 to 216 are repeated.

If it is determined in step 217 that the number K of forward / reverse switching is the set number, the discharge valves 9a, 9b, 9 of the drain pipes 11a, 11b, 11c of the water chambers A, B, C are determined.
c are closed simultaneously or sequentially (step 218), and then the switching counter 22 is reset (step 2).
19), finish the cleaning process.

As described above, in the present embodiment, the cleaning operation is automatically performed every predetermined operation time or when the fluid pressure in the working fluid system exceeds the set value, and the water chamber A , B, C are collected by the drain pipes 11a, 1
Since the working fluid is forcibly discharged directly out of the system from 1b and 11c, the narrow tube inlet is not blocked by dust and the like, and the function of the heat exchanger can be maintained for a long time.

Here, the cleaning operation will be described by way of example when the cleaning operation is performed at a predetermined operation time or when the fluid pressure in the working fluid system exceeds a set value. However, since the properties of the working fluid to be used are known in advance, by setting the interval (operating time) before starting the cleaning operation according to the properties of the working fluid to be used,
The cleaning operation can be performed only at every predetermined operation time or only when the fluid pressure in the working fluid system exceeds a set value.

In this case, while the discharge valve is open, the flow direction of the working fluid is switched between the forward and reverse directions, and the time in the forward and reverse flow directions when the forward and reverse flows are repeated is 30 seconds for the reverse flow and 2 for the forward flow.
The example in which the setting is set to 0 seconds has been described as an example, but the present invention is not limited to this, and it goes without saying that the setting may be appropriately changed according to the properties of the working fluid to be used.

[0032]

As described above, according to the present invention, waste water is used as a working fluid, and heat is exchanged between the working fluid and another heat medium. A drain pipe for forced discharge is newly connected to the water chamber separately from the working fluid system, and a drain valve that can be remotely operated is provided in the middle of these drain pipes. Waste collected in the room is discharged to the outside of the working fluid from each drain pipe, so that the narrow tube inlet is not blocked by dust etc., and the function of the heat exchanger is maintained for a long time. Was completed.

Also, while the discharge valve is open, the flow direction of the working fluid is switched between the forward and reverse directions so that the forward flow and the backward flow are repeated, so that the refuse in each water chamber can be swung and the cleaning effect can be obtained. Could be further enhanced.

Further, the cleaning operation is performed every predetermined operating time, when the fluid pressure in the working fluid system exceeds a set value, or when any one of these states is reached. Was performed efficiently.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a dust discharge device in a shell and tube heat exchanger according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a control unit of the apparatus according to the embodiment.

FIG. 3 is a flowchart of an operation of the apparatus according to the embodiment.

FIG. 4 is a flowchart of an operation of the apparatus according to the embodiment.

[Explanation of symbols]

 Reference Signs List 1 drainage 2 drainage tank 3 pump 4 heat exchanger 5 main pipe (working fluid system) 6a, 6b forward / reverse switching valve 8 narrow pipe A, B, C water chamber 9a, 9b, 9c discharge valve 11a, 11b, 11c drain pipe 12a , 12b Pressure gauge 13 Controller

Claims (10)

[Claims] 1. A wastewater is used as a working fluid, and a water chamber at both ends of a thin tube of a shell-and-tube heat exchanger for exchanging heat between the working fluid and another heat medium is provided separately from a working fluid system. Drain pipes for forced discharge are newly connected, remote controllable discharge valves are provided in the middle of these drain pipes, these drain valves are opened during cleaning, and the refuse accumulated in each water chamber is drained from each drain pipe through the working fluid. A method for discharging refuse in a shell-and-tube heat exchanger, wherein the refuse is discharged outside the system. 2. The shell-and-tube heat exchanger according to claim 1, wherein the flow direction of the working fluid is switched between forward and reverse directions while the discharge valve is open, so that forward flow and reverse flow are repeated. Garbage discharge method. 3. The method according to claim 1, wherein the cleaning operation is performed every predetermined operating time. 4. The refuse in the shell and tube type heat exchanger according to claim 1, wherein the cleaning operation is performed when the fluid pressure in the working fluid system exceeds a predetermined value. Discharge method. 5. The cleaning operation according to claim 1, wherein the cleaning operation is performed at every predetermined operation time and when the fluid pressure in the working fluid system exceeds a predetermined value.
The method for discharging waste in the shell and tube type heat exchanger described in the above. 6. The water chamber at both ends of a thin tube of a shell-and-tube heat exchanger for performing heat exchange between waste water as a working fluid and the working fluid and another heat medium, separately from the working fluid system. A shell-and-tube system in which a drain pipe for forced discharge is newly connected, a discharge valve that can be remotely operated is provided in the middle of the drain pipe, and a control device that controls opening and closing of these discharge valves during cleaning is provided. For refuse discharge in a mold heat exchanger. 7. A forward / reverse switching valve, which can remotely control the flow direction of the working fluid in a forward / reverse direction, is provided in the working fluid system, and the control device activates the forward / reverse switching valve while the discharge valve is open. 7. The apparatus for discharging dust in a shell and tube type heat exchanger according to claim 6, wherein a forward flow and a backward flow of the working fluid are repeated. 8. The system according to claim 6, wherein the control device is set so that the cleaning operation is performed every predetermined operation time. apparatus. 9. A system in which a pressure gauge is provided in a working fluid system, and the control device is set to perform a cleaning operation when the fluid pressure in the system exceeds a predetermined value. The waste discharging device in the shell-and-tube heat exchanger according to claim 6 or 7. 10. A pressure gauge is provided in the working fluid system, and the control device causes the cleaning operation to be performed at every predetermined operation time, and also performs the cleaning operation when the fluid pressure in the working fluid system exceeds a predetermined value. The method for discharging refuse in the shell and tube type heat exchanger according to claim 6 or 7, wherein the refuse is set as follows.