JP4145286B2 - Circulating water heater - Google Patents

Description

  The present invention relates to a circulation type hot water supply apparatus provided with a circulation pump for circulating hot water supplied to various places via a hot water supply pipe via a return pipe.

  For example, in a hotel or the like, a large hot water supply device is installed, hot water is generated by this hot water supply device, and hot water is supplied to guest rooms, kitchens and other places in the hotel via hot water supply pipes. In this case, it is desired that hot water be discharged immediately when the currant is opened, particularly in a guest room. Therefore, a circulation type hot water supply device is known in which a hot water supply device is provided with a circulation pump so that hot water is always circulated through a return pipe (see, for example, Patent Document 1).

Referring to FIG. 4, hot water that has been sucked by circulation pump P and returned via return pipe R may be mixed with air. Therefore, the hot water returned through the return pipe R is separated when passing through the gas-liquid separation unit SP, and this separated air is supplied from an air vent valve AV attached to the upper part of the gas-liquid separation unit SP. Exhausted into the atmosphere. The hot water from which the air has been separated and removed is once supplied to the distributor ST, and the hot water flows from the distributor ST to the circulation pump P through the pipe T. The reason why the two circulation pumps P are connected in parallel is to increase the redundancy so that the circulation of the hot water can be continued by the other circulation pump P when one of them fails. Note that SA is a safety valve that opens when the pressure in the pipe line becomes higher than a predetermined pressure for some reason and releases the pressure to the drain side.
Japanese Patent Laying-Open No. 2003-42571 (FIG. 1)

  When the above-mentioned hot water supply apparatus is newly installed or started after draining hot water in the circulation path for maintenance, the circulation pump P is not filled with hot water. Therefore, if the engine is not started in a state where priming water is injected into the circulation pump P, the hot water cannot be sufficiently sucked into the circulation pump P from the return pipe R, and the circulation of the hot water is not started even after a predetermined time has elapsed since the start. It will be judged as an error. In particular, when the circulation pump P is driven by a DC motor, the rotation speed of the circulation pump P when idling is high, and the circulation pump P may be damaged.

  Although a self-priming type pump may be used as the circulation pump P, the self-priming type circulation pump is more expensive than a non-self-priming type pump, resulting in a problem that the cost of the hot water supply device is increased. Further, since hot water flows relatively easily from the return pipe R to the gas-liquid separation unit SP, the hot water naturally flows into the distributor ST although gradually. However, since the pipe T has an upward slope portion TC, it takes a very long time for the hot water in the distributor ST to naturally flow into the circulation pump P, which is not practical.

  In view of the above problems, an object of the present invention is to provide a circulating hot water supply apparatus that does not require priming water without using a self-priming circulating pump.

In order to solve the above problems, a circulating hot water supply apparatus according to the present invention is a hot water supply apparatus for heating hot water to generate hot water and supplying the hot water to various places through hot water supply pipes. A recirculating pump that returns the warm water through a return pipe, with a circulation function that reheats the hot water sucked by the circulation pump and supplies hot water from the hot water supply pipes to various places. The gas-liquid separation device and the circulation pump are directly connected by piping, and two circulation pumps are attached as the circulation pump. The gas-liquid separation device supplies hot water from the return piping to both circulation pumps. It functions as a distributor that distributes to each other.

In the above-described conventional apparatus, since a distributor serving as a pool of air is disposed between the gas-liquid separator and the circulation pump, hot water does not flow smoothly to the circulation pump. However, in the present invention, the gas-liquid separator and the circulation pump are directly connected so that no part of the air pool is formed between them, so hot water flows into the circulation pump in a short time, and the priming water is separately supplied to the circulation pump. There is no need to fill. Two circulation pumps are attached as the circulation pump, and the gas-liquid separator functions as a distributor that distributes the hot water from the return pipe to both circulation pumps.

  In addition, if the piping which connects the said gas-liquid separator and a circulation pump is shape | molded so that the part which becomes an upward gradient from a gas-liquid separator to a circulation pump may not be produced, it circulates further from a gas-liquid separator. Hot water flows smoothly to the pump.

  As is clear from the above description, the present invention makes it easy for hot water from the return pipe to flow into the circulation pump when the circulation pump is started for the first time, so that priming water is injected without using a self-priming circulation pump. There is no need to do this, and the circulation is started by the first start of the circulation pump, and no error occurs.

  Referring to FIG. 1, reference numeral 1 is an example of a hot water supply apparatus according to the present invention, and includes a hot water supply apparatus main body 11 therein. The hot water supply apparatus body 11 is supplied with water from a water supply pipe 21 drawn from the water supply main pipe 2, heats the water supply inside the hot water supply apparatus body 11, and discharges hot water into the hot water supply pipe 31.

  Hot water in the hot water supply pipe 31 is supplied through the hot water supply main pipe 3 to hot water supply places 4 set in various places. The hot water supply main 3 is connected to a return pipe 5 through a hot water supply point 4. The return pipe 5 is connected to a circulation pump 6, and the discharge side of the circulation pump 6 is connected to a water supply port of the hot water supply apparatus main body 11. Therefore, when the circulation pump 6 is operated, the hot water is circulated from the hot water supply main pipe 3 to the return pipe 5 even when the hot water is not consumed at the hot water supply place 4, and the hot water whose temperature is lowered during the circulation is supplied to the hot water supply apparatus main body. 11 can be heated again and supplied to the hot water supply station 4.

  Since the hot water is constantly circulated in this way, the hot water supply station 4 is always kept in a state where the hot water can be immediately discharged.

  In the present embodiment, two circulation pumps 6 are connected in parallel, and both circulation pumps 6 are alternately operated at a predetermined cycle. Thus, by connecting the two circulation pumps 6 in parallel, even if one of the circulation pumps 6 breaks down, the circulation of hot water can be continued with the other circulation pump 6.

  With reference to FIG. 2, the hot water circulated through the return pipe 5 passes through the safety valve 9 and is then supplied to the distributor 7 once. As shown in FIG. 3, the distributor 7 includes an inflow port 72 at a lower portion, and hot water flows into the distributor 7 from the inflow port 72. The inflow port 72 communicates with an expansion passage 73 extending upward.

  The expansion passage 73 is designed such that the passage area gradually expands along the flow direction of the hot water, and therefore the flow rate of the hot water is decelerated as it flows through the expansion passage 73. When bubbles B are mixed in the warm water, the bubbles rise in the expansion passage 73 by their buoyancy.

  The expansion passage 73 further communicates with the expansion chamber 74. The flow rate of the hot water flowing into the expansion chamber 74 is greatly reduced. Here, all the bubbles B rise and the bubbles B are separated from the hot water. The hot water from which the bubbles B are separated is discharged from the two discharge ports 71.

  An air vent valve 8 is connected to the upper portion of the distributor 7, and the air separated by the distributor 7 is appropriately discharged into the atmosphere by the air vent valve 8. Thus, the distributor 7 simultaneously functions as a gas-liquid separator.

  Returning to FIG. 2, the two discharge ports 71 of the distributor 7 are each connected to the suction port 60 of the circulation pump 6 via a pipe 61. The pipe 61 is arranged so as to be always horizontal or descending from the discharge port 71 toward the suction port 60, so that a portion having an ascending gradient is not generated.

  According to the above configuration, for example, when the hot water supply device 1 is newly installed and started for the first time in a state where the return pipe 5 is not filled with hot water, the water supply pressure is pushed even if the circulation pump 6 is not driven. The hot water naturally reaches the safety valve 9. Although the distributor 7 is initially filled with air, the air in the distributor 7 is pushed into the atmosphere from the air vent valve 8 by being pushed by the supply water pressure, and the safety valve 9 into the distributor 7 for a short time. Then, hot water flows and the distributor 7 is filled with hot water.

  When the inside of the distributor 7 is filled with hot water, hot water flows out from the discharge port 71 to the pipe 61. Since there is no portion where the pipe 61 has an upward gradient as described above, the pipe 61 flows through the pipe 61 as it is by gravity and flows into the circulation pump 6. Since the flowing hot water functions as priming water, even if the start switch is turned on without separately injecting priming water into the circulation pump 6, the circulation pump 6 draws hot water without idling and from the hot water supply main pipe 3 described above. Hot water can be circulated to the return pipe 5.

  In addition, this invention is not limited to an above-described form, You may add a various change in the range which does not deviate from the summary of this invention.

The figure which shows the structure of one embodiment of this invention Diagram showing piping around the circulation pump Diagram showing details of gas-liquid separator Diagram showing piping around conventional circulation pump

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot water supply apparatus 2 Water supply main 3 Hot water supply main 5 Return piping 6 Circulation pump 7 Distributor 8 Air vent valve 9 Safety valve

Claims (2)

A hot water supply device that heats hot water to generate hot water and supplies the hot water to various places through hot water pipes, and includes a circulation pump that returns hot water supplied through hot water pipes through a return pipe. In this system, a gas-liquid separation device is provided upstream of the pump, and the gas-liquid separation device and the circulation pump are directly connected by piping. Two circulating pumps are attached as the circulation pumps, and the gas-liquid separator functions as a distributor that distributes the hot water from the return pipe to both circulation pumps. apparatus.   2. The circulation according to claim 1, wherein a pipe connecting the gas-liquid separator and the circulation pump is formed so as not to have a portion having an upward gradient from the gas-liquid separator to the circulation pump. Water heater.

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