JPS64601B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Subject of the Invention) The present invention relates to an apparatus for disposing a heat exchanger in a water supply pipe leading from a water supply pump to a boiler to transfer heat of discharged condensate to the supply water and recovering it to the boiler.

(Prior Art) Japanese Patent Application No. 55-189178 discloses a condensate recovery device having the following structure. A heat exchanger will be installed in the water supply piping from the water pump to the boiler. Condensate is introduced into the heat exchanger to heat the feed water. Detects the amount of water in the boiler and controls the operation of the water pump.

The above device has the following problems. This device is used for small boilers and supplies water to the boiler intermittently through the water supply piping. When the feed water pump is stopped, the feed water that remains in the heat exchanger is heated by the condensate flowing inside the heat exchanger, and its temperature gradually rises. Therefore, the amount of heat transferred to the water supply decreases, so that high-temperature condensate may be discharged to the outside and generate steam. In particular, if steam is leaking from the steam trap, the temperature of the discharged condensate will rise rapidly, producing extremely strong steam that may harm the surrounding environment.

(Technical Problem) The present invention is a system in which a heat exchanger is placed in the water supply piping from the water supply pump to the boiler to transfer the heat of discharged condensate to the supply water and recover it in the boiler. The purpose is to make the water supply available for other uses.

(Configuration 1) The first configuration of the present invention is as follows. A heat exchanger is placed in the water supply piping from the water supply pump to the boiler. The condensate generated in steam-using equipment, etc. is guided to the heat exchanger through the condensate inflow pipe, and the feed water is heated.
Discharge to the outside through condensate discharge piping. An electrically operated three-way switching valve will be placed in the water supply piping from the heat exchanger to the boiler, and branch piping will be created to lead the water supply to other hot water usage locations. The water supply pump is operated by the water level detection means provided in the boiler, and the three-way switching valve is switched to the boiler side to supply water to the boiler. A means for detecting the temperature of condensate discharged from the heat exchanger is placed in the condensate discharge piping, etc. The discharge condensate temperature detection means detects when the water supply to the boiler is stopped and the discharge condensate temperature is higher than a predetermined value.
Operate the water supply pump and switch the three-way switching valve to the branch piping side to supply water to other hot water usage locations.

The effects of the present invention are as follows. When the water supply to the boiler is stopped, the water remaining in the heat exchanger is heated by condensate and its temperature gradually rises. Therefore, since the amount of heat transferred to the feed water in the heat exchanger gradually decreases, the temperature of the condensate discharged from the heat exchanger through the condensate discharge pipe gradually increases. At this time, when the temperature of the discharged condensate is detected by the temperature detection means and becomes higher than a predetermined value, the water supply pump is operated and the three-way switching valve is switched to the branch piping side to supply water to other hot water usage locations. . Therefore, surplus heated water in the heat exchanger when the water supply is stopped can be used for other purposes. Further, the temperature of the condensate discharged from the condensate discharge passage does not rise above a predetermined value, and steam does not rise violently outside.

(Configuration 2) The second configuration of the present invention is as follows. A heat exchanger is placed in the water supply piping from the water supply pump to the boiler. Condensate generated in steam-using equipment, etc. is guided to the heat exchanger through the condensate inlet piping, where the feed water is heated and discharged to the outside through the condensate discharge piping. An electrically operated three-way switching valve will be placed in the water supply piping from the heat exchanger to the boiler, and branch piping will be created to lead the water supply to other hot water usage locations. The water supply pump is operated by the water level detection means provided in the boiler, and the three-way switching valve is switched to the boiler side to supply water to the boiler. Install a throttle valve in the branch pipe. Using the water level detection means installed in the boiler, when the water supply to the boiler is stopped, the water supply pump is operated, the three-way switching valve is switched to the branch piping side, and a predetermined amount of water is supplied to other hot water usage points through the throttle valve. Let's do it.

The effects of the present invention are as follows. When the water supply to the boiler is stopped, the three-way switching valve is switched to the branch piping side. A throttle valve is placed in the branch pipe, and a predetermined amount of water is supplied from the water supply pump through the heat exchanger to other hot water usage locations. Therefore, surplus heated water in the heat exchanger when the water supply is stopped can be used for other purposes. Furthermore, since the temperature of the condensate discharged from the condensate discharge passage does not become high, no steam is produced.

(Example 1) The example shown in FIGS. 1 and 2 will be described. In Figure 1, water supply piping 3 leading from water supply pump 1 to boiler 2
A heat exchanger 4 is placed at The condensate discharged from the steam trap 7 is introduced into the heat exchanger 4 through the condensate inlet passage 5 to heat the feed water, and the condensate discharge passage 6
It is discharged to the outside through. The steam trap 7 is attached to the outlet of the steam-using equipment 8. This equipment 8
Steam is supplied from the boiler 2 through the steam pipe 9. An electrically operated three-way switching valve 10 is arranged in a portion of the water supply pipe 3 from the heat exchanger 4 to the boiler 2, and a branch pipe 12 is branched to lead the water supply to another hot water usage point 11. The water level in the boiler 2 is detected by a water level detection means 13. The branch pipe 12 has a back pressure regulating valve 14 that opens when the pressure on the inlet side exceeds a set value.
Place. A similar back pressure regulating valve 15 is also arranged in the condensate discharge passage 6 to regulate the pressure and temperature of the condensate flowing in the heat exchanger 4. Further, a temperature detection means 16 for detecting the temperature of condensate is arranged in a portion of the condensate discharge pipe 6 from the heat exchanger 4 to the back pressure regulating valve 15.
17 is an electric motor that drives the water supply pump 1, 18 is a water supply source, and 19 is a check valve that prevents backflow of the water supply. The three-way switching valve 10, the water level detection means 13, the temperature detection means 16, and the electric motor 17 are connected as shown in FIG.

In Figure 2, VX is the contact point of the three-way switching valve 10.
This is a relay that opens and closes VS. In addition, three-way switching valve 1
0 switches to the boiler 2 side when contact VS is closed,
When the contact VS is open, it switches to the branch piping 12 side.
MX is a relay that opens and closes the contact MS of the electric motor 17. Relay LX closes contact LS until the water level in boiler 2 reaches a predetermined low water level from a predetermined high water level, and closes contact LS until it descends and reaches the predetermined low water level.
is open. Relay TX closes contact TS when the temperature of condensate exceeds a predetermined temperature, and opens when the temperature drops below a predetermined temperature. A to E are terminals connected to a power source.

The operation of the above embodiment is as follows. Boiler 2
When the water level in the tank falls and reaches a predetermined low water level, the relay LX of the water level detection means 13 is energized, so the contact
LS is closed and relays VX and MX are energized, so contacts VS and MS are closed. Therefore, the three-way switching valve 10 is switched to the boiler 2 side, and the water supply pump 1 is driven by the electric motor 17, so that the water supply is sent to the boiler 2 through the water supply pump 1, the water supply passage 3, and the heat exchanger 4. Since high-temperature water heated by condensate in the heat exchanger 4 is sent, the amount of heat required for evaporation in the boiler 2 is reduced. When the water level in the boiler 2 rises due to water supply and reaches a predetermined high water level, the water level detection means 13
Since relay LX is deenergized, contact LS opens and relays VX and MX are deenergized. Since the contact point VS is opened, the three-way switching valve 10 is switched to the branch pipe 12 side, and since the contact point MS is opened, the electric motor 17 is stopped. The feed water retained in the heat exchanger 4 is heated by the condensate and its temperature gradually rises, so the amount of heat transferred to the feed water decreases, and the temperature of the condensate discharged from the condensate discharge passage 6 gradually rises. do. When the temperature of the discharged condensate exceeds a predetermined value, the temperature detection means 16 activates the relay TX.
is energized to close contact TS, energize relay MX to close contact MS, and operate electric motor 17. The feed water accumulated in the heat exchanger 4 is supplied to other hot water usage points 1 through the branch pipe 12 by the operation of the feed water pump 1.
Water is supplied to 1. When the temperature of the condensate flowing through the condensate discharge passage 6 falls below a predetermined value, the electric motor 17 stops;
Water supply to other hot water usage points 11 is stopped. Further, when the water level in the boiler 2 drops to a predetermined low water level due to the use of steam, the three-way switching valve 10 is switched to the boiler 2 side, and the electric motor 17 is operated to operate the water supply pump 1.
and starts supplying water to boiler 2. The same operation is repeated thereafter. Therefore, when the water supply to the boiler 2 is stopped, the surplus heated water supply in the heat exchanger 4 can be used at other hot water usage points 11. Also,
The temperature of condensate discharged from the condensate discharge passage 6 does not rise above a predetermined value, and steam does not rise violently outside.

This embodiment has the following unique effects. Since the back pressure regulating valve 15 disposed in the condensate discharge passage 6 does not open unless the pressure of the fluid on the inlet side reaches a predetermined value or more, the pressure of the condensate flowing inside the heat exchanger 4 increases to this set value. , the temperature of the condensate can be raised to a saturation temperature corresponding to this set value. Therefore, it is possible to increase the temperature difference between the condensate and the feed water in the heat exchanger 4, transfer a large amount of heat to the feed water, and heat the feed water to a high temperature.

Like the valve 15 described above, the back pressure regulating valve 14 increases the pressure of the feed water to which heat is transferred from the condensate in the heat exchanger 4 to a set value, and allows the feed water to reach a high temperature corresponding to this set value. . Therefore, a large amount of heat can be transferred from the condensate to the feed water, and high temperature feed water can be supplied to other hot water usage points 11.

(Example 2) The example shown in FIGS. 3 and 4 will be described. However, the first
Equivalent parts common to the embodiment of FIG. 2 are given the same reference numerals, and explanations thereof will be omitted. A throttle valve 31 is arranged in the branch pipe 12 to throttle the flow rate of the water supply flowing therethrough.

The operation of this embodiment will be explained with reference to the wiring diagram shown in FIG. The electric motor 17 is constantly operated and drives the water supply pump 1. When the water level in the boiler 2 decreases and reaches a predetermined low water level, the relay of the water level detection means 13 is activated.
LX is energized to close contact LS, and relay VX is energized to close contact VS. Therefore, the three-way switching valve 10 is switched to the boiler 2 side, and the water is supplied to the boiler 2 through the water supply pump 1, the water supply passage 3, and the heat exchanger 4. The heat of the condensate is transferred to this supplied water in the heat exchanger 4, and the temperature has reached a high temperature, so that the amount of heat required for evaporation in the boiler 2 can be reduced. When the water level in boiler 2 rises to a predetermined high water level due to water supply,
The relay LX of the water level detection means 13 is deenergized and the contact
LS is opened, relay VX is deenergized, and contact VS is opened, so the three-way switching valve 10 is switched to the branch pipe 12 side, and the water supply in the heat exchanger 4 is supplied to a predetermined amount through the branch pipe 12 and the throttle valve 31. Water is then supplied to other hot water usage points 11 one by one. When the water level in the boiler 2 decreases and reaches a predetermined low water level, the three-way switching valve 10
and starts supplying water to the boiler 2.

The same operation is repeated thereafter. In this embodiment, when the water supply to the boiler 2 is stopped, surplus heated water supply in the heat exchanger 4 can be used at other hot water usage points 11. Further, the temperature of the condensate discharged from the condensate discharge passage 6 continues to exchange heat with the supply water flowing in a predetermined amount in the heat exchanger 4, so that it does not become high and steam does not rise violently outside.

This embodiment has the following unique effects. The water supply pump 1 operates all the time, and there is no need to control the operation of the pump 1 based on the temperature of the condensate flowing through the discharge passage 6. Therefore, a means for detecting the temperature of the condensate in the condensate discharge passage 6 can be eliminated, and the electric circuit can be simplified.

(Specific Effects) The present invention has the following specific effects. Condensate discharged from steam-using equipment is contaminated with rust and chemicals such as cleaning agents. The present invention utilizes feed water heated to a high temperature by heat exchange with this condensed water, and this feed water is pure without the above-mentioned contaminants and can be used directly as washing water, for example.

Heat is transferred from the condensate in the heat exchanger, and the heated feed water is sent to the boiler. Therefore, the amount of heat required for evaporation in the boiler is reduced, the amount of fuel used in the boiler is reduced, and fuel costs are reduced.

Since the water supplied to other hot water usage locations is pressurized by a water supply pump, the pressure is high and it can be sent to remote or high-place usage locations, increasing the range of usage.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a heat exchanger type condensate heat recovery device according to an embodiment of the present invention, Fig. 2 is a circuit diagram showing an example of the electric circuit of the embodiment of Fig. 1, and Fig. 3 is a diagram of another embodiment. FIG. 4 is a schematic diagram of an example heat exchanger type condensate heat recovery device, and FIG. 4 is a circuit diagram showing an example of the electric circuit of the embodiment shown in FIG. 1: Water supply pump, 2: Boiler, 3: Water supply piping,
4: Heat exchanger, 5: Condensate inflow pipe, 6: Condensate discharge pipe, 10: Electrically operated three-way switching valve, 11: Other hot water usage points, 12: Branch pipe, 13: Water level detection means, 14 , 15: Back pressure adjustment valve, 16: Temperature detection means, 17: Electric motor, 31: Throttle valve.

Claims (1)

[Claims] 1. A heat exchanger is placed in the water supply piping from the water supply pump to the boiler, and condensate generated in steam-using equipment, etc. is guided to the heat exchanger through the condensate inlet piping to heat the supply water and return it to the boiler. Water is discharged to the outside through the water discharge piping, and an electrically operated three-way switching valve is installed in the water supply piping from the heat exchanger to the boiler, and branch piping is installed to lead the water to other hot water usage points, and installed at the boiler. The water supply pump is operated by the water level detection means, the three-way switching valve is switched to the boiler side to supply water to the boiler, and the temperature of the condensate discharged from the heat exchanger to the condensate discharge pipe etc. is detected. When the water supply to the boiler is stopped and the discharge condensate temperature is higher than a predetermined value, the discharge condensate temperature detection means operates the water supply pump and switches the three-way switching valve to the branch piping side. A heat exchanger type condensate heat recovery device that supplies water to other hot water usage locations. 2. A heat exchanger is placed in the water supply piping from the water supply pump to the boiler, and condensate generated in steam-using equipment, etc. is guided to the heat exchanger through the condensate inflow piping to heat the supply water, and then released to the outside through the condensate discharge piping. An electrically operated three-way switching valve is installed in the section of the water supply piping from the heat exchanger to the boiler, and a branch piping that leads the water supply to other hot water usage points is branched, and a throttle valve is placed on the branch piping. When the water supply to the boiler is stopped, the water level detection means installed in the boiler operates the water supply pump, switches the three-way switching valve to the branch piping side, and supplies a predetermined amount of water to other hot water usage points through the throttle valve. A heat exchanger type condensate heat recovery device.