JP2020085361A - Heat recovery system - Google Patents

Abstract

To provide a heat recovery system capable of preventing rust from being contained in hot water with secured high heat recovery efficiency.SOLUTION: A heat recovery system comprises a first heat recovery device 10, a second heat recovery device 20, a boiler 51, a steam utilization facility device 30, a hot water utilization facility device 40, and a separation unit 70. After water having been subjected to temperature control with the first heat recovery device 10 is further heated by the boiler 51 to become steam, it is supplied to the steam utilization facility device 30, and then used. Water having being subjected to temperature control with the second heat recovery device 20 is supplied to the hot water utilization facility device 40, and then used. The separation unit 70 separates steam drain used in the steam utilization facility device 30 into steam and drain. The steam separated by the separation unit 70 is recovered by the second heat recovery device 20, and the drain separated by the separation unit 70 is recovered by the first heat recovery device 10.SELECTED DRAWING: Figure 1

Description

The present invention relates to a heat recovery system that recovers the heat contained in a steam drain by recovering the steam drain used in another device.

Conventionally, there is known a technique of recovering vapor drain used in another device by an ejector. For example, Patent Document 1 discloses a heat recovery device in which water stored in a tank is circulated by a pump through a circulation pipe, and an ejector provided in the circulation pipe sucks vapor drain. In this heat recovery device, the heat contained in the steam drain can be recovered by mixing the steam drain sucked by the ejector with the circulating water. In the following description, "steam drain" means at least the steam used in another device (for example, a trouser press in a cleaning plant, a steam iron, etc.) and the drain condensed by the steam used in another device. Meaning of one side.

Patent Document 1 also discloses a heat recovery system in which a heat recovery device and a reserve tank storing water are connected by a first pipe and a second pipe. The first pipe connects the outlet of the heat recovery device and the inlet of the reserve tank, and the second pipe connects the outlet of the reserve tank and the inlet of the heat recovery device. In this heat recovery system, convection of water is generated between the heat recovery device and the reserve tank via the first pipe and the second pipe, and the temperature of the water stored in the reserve tank due to heat exchange on the reserve tank side. Is designed to rise.

In the heat recovery system disclosed in Patent Document 1, the heat recovery device and the reserve tank can independently control the temperature of water to be stored at different temperatures. That is, the temperature of the stored water can be controlled to the first temperature (eg, 80° C.) on the heat recovery device side, and the temperature of the stored water can be controlled to the second temperature (eg, 40° C.) lower than the first temperature on the reserve tank side. ) Can be controlled.

When the water temperature in the tank exceeds the first temperature, the temperature control in the heat recovery device reduces the water temperature by discharging a part of the water in the tank and supplying tap water instead. This is a method of maintaining the water temperature near the first temperature. On the other hand, for temperature control in the reserve tank, an opening/closing valve is provided in the first pipe and the second pipe, and while the water temperature in the tank is below the second temperature, the opening/closing valve is opened and the heat is recovered from the heat recovery device by convection of water. When the water temperature reaches the second temperature, the on-off valve is closed to stop the convection of the water to maintain the temperature of the water in the reserve tank near the second temperature.

JP, 2013-57494, A

In Patent Document 1, a cleaning factory is assumed as an application example of the disclosed heat recovery system. In this application example, the water whose temperature is controlled to the first temperature on the heat recovery device side is turned into steam by heating in the boiler, and this steam is supplied to steam utilization equipment (for example, a trouser press or a steam iron). Has become. Further, the water whose temperature is controlled to the second temperature on the reserve tank side is supplied to hot water utilization equipment (for example, a washing machine). Then, the steam used in the steam utilizing facility (used steam) and the drain in which the used steam is condensed are supplied (recovered) to the heat recovery device via the recovery pipe.

The steam drain supplied (recovered) to the heat recovery device is mixed with foreign matter such as iron powder and rust generated from the recovery pipe. Although a permanent magnet for removing iron powder contained in the steam drain is also arranged in the tank of the heat recovery device, the permanent magnet can remove iron powder but cannot remove rust which is iron oxide. For this reason, rust is mixed in the water stored in the tank of the heat recovery device and the reserve tank for convection of water with the heat recovery device. In particular, in hot water utilization equipment that directly uses hot water supplied from a reserve tank, mixing of rust becomes a problem.

Patent Document 1 also discloses a technique of separating the steam drain before recovery into steam and drain, and recovering only the separated steam. In this case, since foreign substances such as rust and iron powder are contained in the drain and not in the steam, it is possible to prevent rust from being mixed into the water stored in the heat recovery device or the reserve tank. However, in this configuration, since the separated drain is not recovered, the heat contained in the drain is not recovered but is discarded, and the heat recovery rate is reduced.

Further, in Patent Document 1, in the method of separating the steam drain before recovery into steam and drain, the recovery pipe is branched into a drain recovery pipe and a steam recovery pipe, and the steam recovery pipe is connected to the upper side of the drain recovery pipe. That is. However, since the steam drain flowing through the recovery pipe is sucked by the ejector of the heat recovery device, the flow is turbulent, and the drain is scattered at the branch point between the drain recovery pipe and the steam recovery pipe. As a result, the scattered drain may be mixed into the steam recovery pipe side. Patent Document 1 does not sufficiently consider the conditions or the like that can prevent scattered drainage from entering the vapor recovery pipe side.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a heat recovery system that can prevent rust from being contained in hot water while ensuring a high heat recovery rate.

In order to solve the above-mentioned problems, the heat recovery system according to the first aspect of the present invention recovers a drain in which steam used in another device is condensed, and heats water by the heat contained in the drain. Heat recovery device for controlling the temperature to a first temperature by means of a first heat recovery device, and second heat recovery device for recovering the steam used in another device and heating water by the heat contained in the steam to control the temperature at the second temperature. A device, a boiler to which water heated by the first heat recovery device is supplied, which further heats the water to generate steam, and a steam which is generated by the boiler are supplied, and uses steam The equipment includes: equipment heated by the second heat recovery device, water supplied by the second heat recovery equipment to utilize the water; equipment used for the steam utilization equipment; steam used in the equipment utilizing steam; and a drain in which the steam is condensed. A steam drain is provided with a separation unit for separating the steam and the drain, the steam separated by the separation unit is recovered by the second heat recovery device, and the drain separated by the separation unit is recovered by the first heat recovery device. It is characterized by collecting.

According to the above configuration, the second heat recovery device that supplies hot water (water whose temperature is controlled to the second temperature) to the equipment using hot water recovers only the steam separated from the steam drain. Since the separated steam does not contain rust in the pipes, it is possible to prevent hot water containing rust from being supplied to the equipment using hot water. On the other hand, since the drain separated from the steam drain is recovered by the first heat recovery device and used for heating water, the heat contained in the drain can be used without being discarded, and the heat recovery system has a high heat recovery rate. Can be secured.

Further, in the heat recovery device, the separation unit includes a steam drain pipe in which the steam drain is inserted, a steam pipe in which the steam is inserted, and a drain pipe in which the drain is inserted, The steam drain pipe is branched into the steam pipe and the drain pipe, the steam pipe is connected to the upper side of the steam drain pipe, from the uppermost inner surface of the pipe in the drain pipe to the pipe in the steam pipe. When the steam pipe height H is the distance to the bottom of the surface, the steam pipe height H can be 50 mm or more.

According to the above configuration, by setting the steam pipe height H to 50 mm or more, it is possible to prevent the drain from being mixed into the steam pipe in the separation section, and to reliably separate the steam from the steam drain.

In order to solve the above-mentioned problems, the heat recovery system according to the second aspect of the present invention uses a steam drain composed of steam used in another device and a drain in which the steam is condensed into a steam and a drain. A separation unit that separates and a heat recovery device that recovers the steam separated in the separation unit and heats water by the heat contained in the steam, and the separation unit is a steam drain pipe through which the steam drain is inserted. And a steam pipe through which the steam is inserted, and a drain pipe through which the drain is inserted, the steam drain pipe is branched into the steam pipe and the drain pipe, and the steam pipe is the When the steam pipe height H is connected to the upper side of the steam drain pipe and the distance from the uppermost portion of the inner surface of the drain pipe to the lowermost portion of the inner surface of the pipe of the steam pipe is defined as the steam pipe height H, the steam pipe height H is It is characterized by being 50 mm or more.

According to the above configuration, by setting the steam pipe height H to 50 mm or more, it is possible to prevent the drain from being mixed into the steam pipe in the separation section, and to prevent rust in the heat recovery device that heats water by the heat of the recovered steam. It is possible to prevent the supply of hot water mixed with.

Since the heat recovery system of the present invention supplies hot water to the hot water utilization facility equipment from the second heat recovery device that recovers the steam separated from the steam drain, hot water containing rust is supplied to the hot water utilization equipment equipment. There is an effect that can prevent. In addition, by collecting the drain separated from the steam drain by the first heat recovery device, it is possible to ensure a high heat recovery rate.

1 is a schematic diagram showing an embodiment of the present invention and is a diagram showing a configuration of a heat recovery system. FIG. FIG. 1, showing an embodiment of the present invention, is a front view of a heat recovery device. FIG. 3 is a left side view of the heat recovery device of FIG. 2. It is a right view of the heat recovery apparatus of FIG. It is a top view of the heat recovery apparatus of FIG. It is sectional drawing which shows an example of the ejector arrange|positioned at the heat recovery apparatus of FIG. It is a figure which shows the isolation|separation part provided in the heat recovery system of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of a heat recovery system according to this embodiment (hereinafter referred to as the present system). As shown in FIG. 1, the present system includes a first heat recovery device 10, a second heat recovery device 20, a steam utilization facility device 30, and a hot water utilization facility device 40 as main components, and these devices are provided. And the equipment is connected by various pipes. In FIG. 1, various pipes are not shown, and only the flow of steam, drain, or hot water through the pipes is shown by arrows.

This system can be applied to various facilities that handle steam and hot water, such as a cleaning plant. In a cleaning plant, steam is generated by a boiler, and the generated steam is supplied to a trouser press, a steam iron and the like. Here, a trouser press, a steam iron, etc. are equivalent to the steam utilization facility device 30 of FIG. In addition, hot water is supplied to the washing machine and the like. Here, the washing machine or the like corresponds to the hot water utilization facility device 40 of FIG. Steam (used steam) used in a trouser press, a steam iron, etc., and a drain in which the used steam is condensed are supplied to the first heat recovery device 10 and the second heat recovery device 20 via a recovery pipe (recovery). ) Will be done.

-Structure of heat recovery device-
The first heat recovery device 10 and the second heat recovery device 20 recover the steam drain used in another device (here, the steam utilization facility device 30), and efficiently heat water by the heat of the recovered steam drain. However, the temperature of the obtained water is controlled. The first heat recovery device 10 and the second heat recovery device 20 are basically heat recovery devices having the same structure, but have different control temperatures of water. In this system, the control temperature in the first heat recovery device 10 is the first temperature T1 (for example, 80° C.), and the control temperature in the second heat recovery device 20 is the second temperature T2 lower than the first temperature T1 (for example, 40°C). Hereinafter, the specific configuration of the heat recovery device will be described by taking the first heat recovery device 10 (hereinafter, simply referred to as the heat recovery device 10) as an example.

FIG. 2 is a front view showing an example of the heat recovery device 10 according to the present embodiment. FIG. 3 is a left side view of the heat recovery device 10 of FIG. FIG. 4 is a right side view of the heat recovery device 10 of FIG. FIG. 5 is a top view of the heat recovery device 10 of FIG.

The heat recovery device 10 includes a permanent magnet 11, an ejector 12, a pump 13, a ball tap 14, a temperature control unit 15, a tank 16, and an inspection lid 17.

The tank 16 stores water, and here is a tank having a quadrangular prism shape having a water amount of about 250 liters. Further, a ball tap 14 that supplies and stops tap water according to the elevation of the water level is provided above the tank 16, and the water level of the tank 16 is controlled by the ball tap 14. In the following description, the term "water" is used in a broad sense including "hot water" and "hot water".

When the water level in the tank 16 falls below the lower limit water level, the valve is opened by the ball tap 14 and tap water is supplied from the pipe P43. Then, when the water level in the tank 16 reaches the reference water level, the valve is closed by the ball tap 14 and the supply of tap water is stopped. Further, for example, when a large amount of drain is collected by the ejector 12 and the water level in the tank 16 exceeds the upper limit water level, the water is discharged through the pipes P41 and P42.

The pump 13 is, for example, a stainless steel (for example, SUS304) centrifugal pump, and circulates the water stored in the tank 16 through circulation pipes P31, P32, P33, and P34. A valve V31 is provided at a connecting portion between the circulation pipe P32 and the circulation pipe P33. A pressure gauge M32 is provided in the circulation pipe P33. Further, the ejector 12 is provided at a connecting portion between the circulation pipe P33 and the circulation pipe P34. The permanent magnet 11 is arranged on the outflow side of the circulation pipe P34.

The flow rate of water supplied (circulated) to the ejector 12 can be increased or decreased by opening/closing the valve V31. That is, as the opening degree of the valve V31 is larger, the flow rate of water supplied to the ejector 12 can be increased. As will be described later, in the ejector 12, the flow path of water is narrowed, so that the larger the opening of the valve V31, the larger the water pressure on the inflow side of the ejector 12 measured by the pressure gauge M32.

The permanent magnet 11 is arranged on the outflow side of the circulation pipe P34 and removes iron from water. The permanent magnet 11 is a columnar bar magnet in which a plurality of (for example, five) magnetic domains are provided in series. In this case, since the magnetic field at the boundary between the magnetic domains (position where the S pole and the N pole are adjacent to each other facing each other) is the largest, the iron content in the water is adsorbed at the boundaries of the four magnetic domains to remove the iron. It will be.

The inspection lid 17 is provided on the upper surface of the tank 16 so as to be openable and closable, and allows the permanent magnet 11 to be inspected, removed, and attached. That is, by opening the inspection lid 17, it is possible to visually recognize the situation where iron powder or the like is attached to the permanent magnet 11 from the outside. Further, by opening the inspection lid 17, it is possible to insert a hand, a jig or the like from the inspection lid 17, remove the permanent magnet 11, remove the attached iron powder and the like, and then attach the permanent magnet 11.

The ejector 12 is provided in the circulation pipes P33 and P34, sucks the steam drain supplied from the trouser press, the steam iron and the like through the pipe P21 (see FIG. 4), and circulates the water circulated by the pump 13. The vapor drain is recovered by mixing with. A compound meter M20 is arranged in the pipe P21. The compound meter M20 measures the negative pressure generated by the ejector 12.

A vacuum break valve 12A and a check valve 12B are provided between the pipe P21 and the ejector 12. When the negative pressure generated by the ejector 12 and detected by the compound gauge M20 becomes excessive, the vacuum break valve 12A is in the "open" state and sucks the atmosphere (air) through the pipe (not shown). The negative pressure is thereby reduced. The check valve 12B is a valve that is provided between the vacuum break valve 12A and a pipe (not shown) to prevent water from flowing out from the ejector 12 to the pipe.

-Temperature control in heat recovery device-
When the water in the tank 16 reaches a preset control temperature, the temperature control unit 15 discharges a part of the water in the tank 16 and then supplies tap water to the tank 16. The temperature of the water in the tank 16 is controlled. The temperature control unit 15 includes a thermometer 151, a thermostat 152, an electric valve 153, and a control unit 154 (not shown).

The electric valve 153 is set to the “open” state according to the instruction from the control unit 154 when the water in the tank 16 is discharged, and the instruction from the control unit 154 when the discharge of the water in the tank 16 is stopped. According to the above, it is an electrically operated valve that is brought into a “closed” state. When the electric valve 153 is in the "open" state, the water in the tank 16 flows out to the pipe P32 via the pipes P51 and P52 and is discharged.

The thermometer 151 detects the temperature of the water in the tank 16 and displays the detection result visually from the outside. Here, for convenience, as the thermometer 151, the reference numeral is given to the position where a meter for displaying the temperature of the water in the tank 16 is provided.

The thermostat 152 determines whether or not the water in the tank 16 has reached the first temperature T1. When the thermostat 152 determines that the water has reached the first temperature T1, the control unit 154 determines that The electric valve 153 is brought into the “open” state. When the electric valve 153 is in the “open” state, the water in the tank 16 flows out to the pipe P32 via the pipes P51 and P52, and the water level in the tank 16 decreases. Then, when the water level in the tank 16 falls below the lower limit water level, the valve is opened by the ball tap 14 and tap water is supplied. When the supply of tap water is started, the temperature of the water in the tank 16 begins to drop.

The thermostat 152 determines whether or not the water in the tank 16 has reached the third temperature T3 (for example, 70° C.), and the thermostat 152 has determined that the third temperature T3 has been reached. At some times, the control unit 154 puts the electric valve 153 in the “closed” state. That is, the electric valve 153 is in the “open” state, and the water in the tank 16 flows out to the pipe P32 via the pipes P51 and P52 and is discharged because the water in the tank 16 has the third temperature. It is limited to the case where it is in the range of T3 (for example, 70° C.) or higher and the first temperature T1 (for example, 80° C.) or lower.

In the present embodiment, the case where the water in the tank 16 is discharged when the electric valve 153 is in the “open” state has been described, but when the electric valve 153 is in the “open” state. Alternatively, the water in the tank 16 may be supplied to another device (for example, a boiler).

In addition, the water controlled to the temperature in the vicinity of the first temperature T1 (for example, 80° C.) in the tank 16 as described above is supplied to the boiler or the like via the pipe P61.

Further, the pipe P32 is formed with a pressure feed port 133, and the pipe P33 is formed with a pressure feed port 134. The pressure feed port 133 and the pressure feed port 134 are openings that use the pump pressure of the pump 13 to pressure feed the water in the tank 16 to another device (for example, a boiler, a washing machine, or the like).

In this way, the water stored in the tank 16 is circulated by the pump 13 through the circulation pipes P31, P32, P33, P34. Then, the ejector 12 provided in the circulation pipes P31, P32, P33, P34 sucks the vapor drain and mixes it with the circulating water to collect the vapor drain, so that the vapor drain can be efficiently used. Can be recovered.

Further, the ejector 12 mixes the recovered steam drain with the circulating water to give the amount of heat contained in the steam drain to the circulating water, thereby heating the water in the tank 16. It Then, when the water in the tank 16 reaches the preset first temperature T1 (for example, 80° C.), after discharging a part of the water in the tank 16, the water is replenished in the tank 16. As a result, the temperature of the water in the tank 16 is controlled, so that the temperature of the discharged water can be controlled to the first temperature T1.

In the present embodiment, the case where the control unit 154 sets the electric valve 153 to the “closed” state when the thermostat 152 determines that the third temperature T3 is reached will be described. The electric valve 153 may be in the “closed” state when tap water is supplied by the valve in the “opened” state. In this case, the temperature of the water supplied to the boiler (not shown) is approximately the first temperature T1 (for example, 80° C.), and the temperature of the water supplied to the boiler can be controlled more strictly.

In the above description, since the first heat recovery device 10 is taken as an example, the temperature controller 15 controls the temperature between the first temperature T1 (for example, 80° C.) and the third temperature T3 (for example, 70° C.). It is controlled to be adjusted. On the other hand, the second heat recovery device 20 controls the water in the tank 16 to the second temperature T2 (for example, 40° C.), and its temperature control method is also different from that of the first heat recovery device 10. Can be a method. Specifically, in the second heat recovery device 20, an automatic control valve 60 (see FIG. 1) is arranged in the recovery pipe on the upstream side of the ejector 12, and the automatic control is performed when the water in the tank 16 reaches the second temperature T2. The valve 60 is put in the “closed” state. By closing the automatic control valve 60, the heat supply to the second heat recovery device 20 is stopped, and the water in the tank 16 of the second heat recovery device 20 is maintained near the second temperature T2. The automatic control valve 60 may be connected to the temperature control unit 15 in the second heat recovery device 20, and the opening/closing control may be performed by the temperature control unit 15. Further, when the automatic control valve 60 is “closed”, all of the steam drain recovered from the steam utilizing facility device 30 is supplied to the first heat recovery device 10.

-Structure and operation of ejector-
Next, the structure of the ejector 12 will be described with reference to FIG. FIG. 6 is a sectional view showing an example of the ejector 12 arranged in the heat recovery device 10 of FIG. The ejector 12 includes a water inlet 121, a first taper portion 122, a first nozzle 123, a mixing chamber 124, a second taper portion 125, a second nozzle 126, a retention chamber 127, a water outlet 128, and a drain suction port 129. ing.

The water inlet 121 is an opening into which water stored in the tank 16 is pumped by the pump 13 and sequentially flows in through the circulation pipes P31, P32, and P33. That is, the water inlet 121 is screwed (or fitted) to one end portion of the circulation pipe P33 (not shown).

The first taper portion 122 guides the water flowing from the water inlet 121 to the first nozzle 123 along the tapered taper. The first nozzle 123 is formed at the tip of the first tapered portion 122, and discharges the water flowing from the water inlet 121 to the mixing chamber 124 at high speed. Since the water is discharged from the first nozzle 123 to the mixing chamber 124 at a high speed, a negative pressure is generated in the mixing chamber 124 due to the so-called “Venturi effect”. Then, due to the negative pressure generated in the mixing chamber 124, the vapor drain supplied through the pipe P21 (see FIG. 4) is sucked from the drain suction port 129, and the sucked vapor drain is discharged from the first nozzle 123. It is mixed with fresh water in the mixing chamber 124. In the following description, a mixture of steam drain and water is referred to as a "mixed liquid" for convenience.

The second taper portion 125 guides the mixed liquid in the mixing chamber 124 to the second nozzle 126 along a tapered taper. Here, the opening area of the second nozzle 126 is set larger than the opening area of the first nozzle 123. The second nozzle 126 is formed at the tip of the second taper portion 125 and discharges the mixed liquid in the mixing chamber 124 to the retention chamber 127.

The retention chamber 127 temporarily retains the mixed liquid discharged from the second nozzle 126, and has a water outlet 128 formed on the downstream side. The water outlet 128 is an opening that allows the mixed liquid discharged from the second nozzle 126 to flow into the tank 16 via the circulation pipe P34 (see FIG. 2).

As shown in FIG. 1, the ejector 12 having the above-described configuration is provided between the circulation pipes P33 and P34 so that the steam drain supplied through the pipe P21 (see FIG. 4) is drained. 129 can be efficiently recovered, and the recovered steam drain can be mixed with the circulating water to recover the amount of heat contained in the steam drain.

− Configuration and operation of heat recovery system −
As described above, in the present system, the control temperature in the first heat recovery device 10 is the first temperature T1 (for example, 80° C.), and the control temperature in the second heat recovery device 20 is the second temperature T2 (for example, 40° C.). ℃). The water whose temperature is controlled to the first temperature T1 in the first heat recovery device 10 is supplied to the boiler 51 via the pump 52, and is turned into steam by further heating in the boiler 51. The steam generated by the boiler 51 is supplied to and used by the steam utilizing facility device 30. Further, the water whose temperature is controlled to the second temperature T2 in the second heat recovery device 20 is directly supplied from the second heat recovery device 20 to the hot water utilization facility device 40 and used. The steam utilization facility device 30 and the hot water utilization facility device 40 incorporated in the present system are not limited to one unit, and a plurality of units may be incorporated in the present system.

The steam drain after being used in the steam utilization facility device 30 is supplied (recovered) to the first heat recovery device 10 and the second heat recovery device 20 via the recovery pipe. However, in this system, the separation unit 70 (see FIG. 1) is provided in the middle of the recovery pipe, and the steam drain recovered from the steam utilization facility device 30 is separated into steam and drain in the separation unit 70.

Here, the separation unit 70 according to the present embodiment will be described with reference to FIG. 7. The separation unit 70 includes a steam drain pipe 71 through which a steam drain is inserted, a steam pipe 72 through which steam is inserted, and a drain pipe 73 through which a drain is inserted. Further, the steam drain pipe 71 is branched into a steam pipe 72 and a drain pipe 73, and the steam pipe 72 is connected to the upper side of the steam drain pipe 71.

Since the steam pipe 72 is connected to the upper side of the steam drain pipe 71, of the steam drains inserted through the steam drain pipe 71, only the steam is sucked toward the steam pipe 72 side, and the remaining drain (including the steam is included. In some cases) is sucked toward the drain pipe 73 side. That is, the steam drain pipe 71 through which the steam drain is inserted branches into a steam pipe 72 through which steam is inserted and a drain pipe 73 through which the drain is inserted, and the steam pipe 72 is located above the steam drain pipe 71. , The steam drain can be separated into steam and drain with a simple configuration.

In the present system, the steam pipe 72 is connected to the ejector 12 of the second heat recovery device 20 as the above-mentioned pipe P21, and only the steam separated from the steam drain is recovered in the second heat recovery device 20. On the other hand, the drain pipe 73 is connected to the ejector 12 of the first heat recovery device 10 as the above-mentioned pipe P21, and the drain separated from the steam drain is recovered by the first heat recovery device 10.

At this time, the iron content (iron powder and rust) in the steam drain remains as a residue in the drain, and the steam does not contain iron. Then, the steam containing no iron is recovered by the second heat recovery device 20 and mixed with the circulated water, so that the iron contained in the steam drain is mixed with water on the second heat recovery device 20 side. Never. In the above description, the first heat recovery device 10 and the second heat recovery device 20 have basically the same structure, but the steam recovered by the second heat recovery device 20 does not contain iron. Therefore, the permanent magnet 11 described above may be omitted in the second heat recovery device 20.

As described above, the second heat recovery device 20 directly supplies the water whose temperature is controlled to the second temperature T2 to the hot water utilization facility device 40, but the steam recovered by the second heat recovery device 20 contains iron components. Does not include (especially rust). As a result, it is possible to prevent rust from mixing in the hot water supplied to the hot water utilization equipment 40.

On the other hand, in the first heat recovery device 10 for recovering the drain, the iron component (iron powder or rust) in the drain is mixed with the circulating water. Iron powder can be removed by the permanent magnet 11, but rust cannot be removed by the permanent magnet 11. Therefore, the temperature is controlled in the first heat recovery device 10, and the discharged water contains rust.

However, the water discharged from the first heat recovery device 10 is supplied to the boiler 51, converted into steam in the boiler 51, and then supplied to the steam utilization facility device 30. In this case, even if rust is mixed in the water supplied to the boiler 51, the steam supplied to the steam utilization facility device 30 does not contain rust, so that no particular problem occurs. Even in this case, the strainer 53 (see FIG. 1) is arranged between the first heat recovery device 10 and the boiler 51 (preferably between the first heat recovery device 10 and the pump 52). It is preferable that the rust is removed to some extent.

As described above, in the present system, since the second heat recovery device 20 that supplies hot water to the hot water utilization facility device 40 recovers only the steam separated from the steam drain, the hot water utilization facility device 40 is rusted. It is possible to prevent the supply of hot water mixed with. Further, since the drain separated from the steam drain is recovered by the first heat recovery device 10 and used for heating water, the heat contained in the drain can be used without being wasted, and this system has a high heat recovery rate. Can be secured.

In the above description, the separation unit 70 separates the steam drain into steam and drain. Further, the separation unit 70 connects the steam pipe 72 to the upper side of the steam drain pipe 71 to branch the steam drain pipe 71 into a steam pipe 72 and a drain pipe 73. However, in the separation unit 70 having the above-described configuration, the flow of the drain flowing through the steam drain pipe 71 and the drain pipe 73 is turbulent, and the drain is scattered at the branch point between the steam pipe 72 and the drain pipe 73 and scattered. Drain may mix into the steam pipe 72. Therefore, in order to surely separate the steam in the separating unit 70 (prevent the mixing of the drain into the steam pipe 72), the steam pipe 72 is arranged at a sufficient height from the steam drain pipe 71 and the drain pipe 73. It seems necessary to do.

The inventor of the present application changed the inter-axis distance L (see FIG. 7) between the steam pipe 72 and the drain pipe 73 in the separation unit 70, and performed a comparative experiment on the steam separation effect. Here, there are two types of pipe inner diameters, 35.7 mm (nominal diameter 32A) and 52.9 mm (nominal diameter 50A), and when the pipe inner diameter is 35.7 mm, the axial distance L is between 60 mm and 110 mm. When the pipe inner diameter was 52.9 mm, the axial distance L was changed from 80 mm to 130 mm in steps of 10 mm. Further, in this comparative experiment, the downstream side of the steam pipe 72 is made to reach a vacuum to perform suction, and the degree of vacuum is −0.1 MPa, −0.09 MPa, −0 under all conditions (pipe inner diameter and axial distance). The experiment was conducted in three stages of 0.08 MPa.

The evaluation method is to run a steam drain mixed with foreign matter corresponding to rust in the steam drain pipe 71, cool the steam separated in the steam pipe 72 to condense, and then visually check the foreign matter contained in the condensed water. confirmed. The results are shown in Table 1 below.

Examples 1 to 9 and Comparative Examples 1 to 9 are results when the pipe inner diameter is 35.7 mm, and in Examples 1 to 9 in which the axial distance L is 90 mm or more, the steam separated in the steam pipe 72 is No foreign matter was confirmed in the condensed water, and a good separation result was obtained. On the other hand, in Comparative Examples 1 to 3 in which the inter-axis distance L was 80 mm, a slight amount of foreign matter was admitted, and in Comparative Examples 4 to 9 in which the inter-axial distance L was 70 mm or less, a greater amount of foreign matter was admitted. ..

Examples 10 to 18 and Comparative Examples 10 to 18 are results when the pipe inner diameter is 52.9 mm, and in Examples 10 to 18 in which the axial distance L is 110 mm or more, the steam separated in the steam pipe 72 is No foreign matter was confirmed in the condensed water, and a good separation result was obtained. On the other hand, in Comparative Examples 10 to 12 in which the inter-axis distance L was 100 mm, a slight amount of foreign matter was admitted, and in Comparative Examples 13 to 18 in which the inter-axial distance L was 90 mm or less, a greater amount of foreign matter was admitted. ..

As is clear from the results shown in Table 1, when the inner diameter of the pipe is 35.7 mm and when the inner diameter of the pipe is 52.9 mm, if the distance L between the shafts is short, vapor separation in the separation section 70 becomes insufficient, and the distance L between the shafts becomes L The vapor separation in the separation unit 70 could be reliably performed by increasing the length.

It should be noted that when the pipe inner diameter is 35.7 mm, the inter-axial distance L that can reliably perform vapor separation in the separation unit 70 is 90 mm or more, and when the pipe inner diameter is 52.9 mm, the vapor separation in the separation unit 70 is performed. The distance L between the axes that can be reliably performed is 110 mm or more, and there is a difference in these numerical values. On the other hand, assuming that the distance from the uppermost portion of the inner surface of the drain pipe 73 to the lowermost portion of the inner surface of the steam pipe 72 is the steam pipe height H (see FIG. 7), when the pipe inner diameter is 35.7 mm, the separation portion The steam pipe height H capable of reliably performing the steam separation in 70 is 54.3 (=90-35.7) mm or more, and when the pipe inner diameter is 52.9 mm, the steam separation in the separation unit 70 is ensured. The height H of the steam pipe that can be performed is 57.1 (=110-52.9) mm or more.

From this, in order to surely perform the vapor separation in the separation unit 70, the vapor pipe height H is preferably 50 mm or more, and more preferably 55 mm or more.

The embodiments disclosed this time are exemplifications in all respects, and are not a basis for a limited interpretation. Therefore, the technical scope of the present invention should not be construed only by the above-described embodiments, but should be defined based on the claims. Also, the meaning equivalent to the scope of claims and all modifications within the scope are included.

10 First Heat Recovery Device 20 Second Heat Recovery Device 30 Steam Utilization Equipment Device 40 Hot Water Utilization Equipment Device 11 Permanent Magnet 12 Ejector 13 Pump 14 Ball Tap 15 Temperature Control Unit 151 Thermometer 152 Thermostat 153 Electric Valve 154 Control Unit 16 Tank 17 Inspection Lid 51 Boiler 52 Pump 53 Strainer 60 Automatic control valve 70 Separation part 71 Steam drain pipe 72 Steam pipe 73 Drain pipe

Claims (3)

A first heat recovery device that recovers a drain in which steam used in another device is condensed, and heats water by heat contained in the drain to control the temperature to a first temperature;
A second heat recovery device that recovers steam used in another device, heats water with heat contained in the steam, and controls the temperature to a second temperature;
A boiler supplied with water heated by the first heat recovery device and further heating the water to generate steam,
Steam generated by the boiler is supplied, steam-utilizing equipment that utilizes the steam,
Water heated by the second heat recovery device is supplied, and equipment for using hot water uses the water,
A steam drain comprising steam used in the steam utilizing equipment and a drain in which the steam is condensed, and a separation unit for separating the steam and the drain,
A heat recovery system characterized in that the steam separated by the separation unit is recovered by the second heat recovery device, and the drain separated by the separation unit is recovered by the first heat recovery device. The heat recovery system according to claim 1, wherein
The separation unit includes a steam drain pipe in which the steam drain is inserted, a steam pipe in which the steam is inserted, and a drain pipe in which the drain is inserted,
The steam drain pipe is branched into the steam pipe and the drain pipe, the steam pipe is connected to the upper side of the steam drain pipe,
When the distance from the uppermost portion of the inner surface of the drain pipe to the lowermost portion of the inner surface of the steam pipe is defined as the steam pipe height H, the steam pipe height H is 50 mm or more. system. A vapor drain comprising a vapor used in another device and a drain in which the vapor is condensed, a separation unit for separating the vapor and the drain,
A heat recovery device for recovering the steam separated by the separation unit and heating water by the heat contained in the steam,
The separation unit includes a steam drain pipe in which the steam drain is inserted, a steam pipe in which the steam is inserted, and a drain pipe in which the drain is inserted,
The steam drain pipe is branched into the steam pipe and the drain pipe, the steam pipe is connected to the upper side of the steam drain pipe,
When the distance from the uppermost portion of the inner surface of the drain pipe to the lowermost portion of the inner surface of the steam pipe is defined as the steam pipe height H, the steam pipe height H is 50 mm or more. system.

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