JP3753914B2 - Hot water system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hot water supply system applied to, for example, a housing complex.
[0002]
[Prior art]
For example, in an apartment house, etc., there are the following systems as a central hot water supply system that branches from a hot water supply main line to supply hot water to each dwelling unit and measures the amount of hot water used for each dwelling unit with a hot water meter. Each system had its own problems.
(1) The hot water supply branch pipe in the dwelling unit is a circulation path that branches from the hot water supply side main pipe, passes through each hot water use location in the dwelling unit, and merges with the hot water supply return side main pipe, and two places immediately after the branch and immediately before the merge A system that measures the difference between the two hot water meters using the amount of hot water used.
In this system, by using two hot water meters, a measurement error occurs in each hot water meter, and the amount of hot water used by the two hot water meters cannot be calculated in a path in which the hot water is constantly circulated (hot water is not supplied). Even when not in use, there is a problem that the accumulated metering is erroneously measured due to an error of the hot water meter.
(2) The hot water branch pipe in the dwelling unit is branched from the hot water outlet main pipe and hot water is supplied to each hot water use location in the dwelling unit, but the hot water branch pipe in the dwelling unit is not used as a hot water circulation path. A system that does not return hot water to the hot water return side main pipe, and measures the amount of hot water used by installing a hot water meter immediately after branching of the hot water branch pipe in the dwelling unit from the hot water outgoing side main pipe.
In this system, since hot water is not circulated after branching of the hot water branch branch in the dwelling unit from the hot water outlet main pipe, if hot water is used from a state where hot water has not been used for a long time, There was a problem that cold hot water was discharged.
[0003]
In order to solve the above problems, a hot water supply system disclosed in JP-A-3-291428 (hereinafter referred to as a prior-art hot water supply system) has been proposed. This prior-art hot water supply system uses a branch pump in the dwelling unit as a circulation path independent of the hot water main pipe, forcibly circulates hot water using a circulation pump, and always performs heat exchange with the hot water main pipe using a heat exchanger. The branch line in the dwelling unit is connected with a replenishing water pipe, and a hot water meter is installed in the replenishing water pipe.
[0004]
According to such a hot water supply system of the prior application, the hot water in the branch pipe in the dwelling unit is always warmed up without using the hot water for a long time, so that the hot water at the beginning of use is not cooled. In addition, since the makeup water pipe for measuring the amount of hot water used is not a circulation path of the hot water, there is an effect that the problem of measuring error in the amount of hot water used does not occur.
[0005]
[Problems to be solved by the invention]
Since the hot water supply system of the prior application is configured as described above, it has been found that the following points should be considered in order to make the hot water supply system practical and efficient. That is, even if the hot water in the branch pipe is still sufficiently warm, if the circulation pump is operated at all times, it will increase the burden of electricity costs for the user. When the temperature is still sufficiently warm, it is necessary to control the circulation pump ON / OFF.
[0006]
In addition, the above-mentioned hot water supply system of the prior application normally functions without any problem, but in the following cases, there is a problem that a phenomenon in which the pipe pressure in the hot water supply circulation line rises abnormally occurs.
(1) During regular inspections, the hot water in the hot water circulation pipeline is drained and inspected, and then charged again to increase the temperature.
(2) When the circulation pump is stopped for a long period of time, etc., and the user goes out, starts the circulation pump again when returning home, and raises the temperature of the hot water in the hot water supply circulation line.
In other words, when the temperature of hot water that has once cooled down is increased, the volume of hot water is expanded, but there is no way to relieve the hot water pressure in the hot water circulation pipe by means of a check valve, so the pipe pressure is abnormal. The phenomenon of rising will occur. Thereafter, when the temperature is raised from 20 ° C. to 45 ° C., the pressure in the tube may exceed 1 MPa.
[0007]
When an abnormal increase in the pressure in the pipe as described above occurs, an excessive load is applied to the circulation pump or branch pipe, etc., damage to the circulation pump or damage to weakly-strengthened parts such as joints of the branch pipe, or As a result, the hot-water tap breaks, and the occupant suffers great physical damage due to water leakage. Even if the equipment does not break down, if the resident opens the hot water tap when the pipe pressure is high, the hot water discharges abnormally, which may cause the resident to burn in the worst case. is there.
[0008]
The present invention has been made to solve the above-described problems, and can prevent an abnormal increase in pipe pressure, damage to a circulation pump, a branch pipe, a hot water tap, and the like caused by the abnormal increase in pipe pressure, and An object of the present invention is to obtain a hot water supply system capable of preventing damage due to water leakage or the like caused by the breakage.
[0009]
Another object of the present invention is to obtain a hot water supply system that can prevent abnormal discharge of hot water supply and has no danger of occupants being burned.
[0010]
[Means for Solving the Problems]
In the hot water supply system according to the present invention, a hot water supply main line for supplying hot water is connected to the primary side chamber of the heat exchange means having a primary side chamber and a secondary side chamber, and hot water is supplied to the hot water use means in the secondary side chamber. A hot water circulation branch pipe for supplying hot water is connected to the hot water circulation branch pipe, and hot water circulation means for forcibly circulating hot water is provided, and a supplementary water pipe for supplying hot water branched from the hot water main pipe is connected to the hot water circulation branch pipe In this hot water supply system, the surplus hot water supply is provided with a measuring means for hot water supply and provided with surplus hot water discharge means for discharging surplus hot water from the hot water circulation branch and / or the heat exchanging means. The discharge means comprises a communication pipe that communicates the hot water supply main line and the hot water supply circulation branch line, and a backflow prevention means that is installed in the communication pipe.
[0011]
[Means for Solving the Problems]
In the hot water supply system according to the present invention, a hot water supply main line for supplying hot water is connected to the primary side chamber of the heat exchange means having a primary side chamber and a secondary side chamber, and hot water is supplied to the hot water use means in the secondary side chamber. A hot water circulation branch pipe for supplying hot water is connected to the hot water circulation branch pipe, and hot water circulation means for forcibly circulating hot water is provided, and a supplementary water pipe for supplying hot water branched from the hot water main pipe is connected to the hot water circulation branch pipe In this hot water supply system, the surplus hot water supply is provided with a measuring means for hot water supply and provided with surplus hot water discharge means for discharging surplus hot water from the hot water circulation branch and / or the heat exchanging means. The discharge means is constituted by a communication pipe that communicates the hot water supply main line and the hot water supply circulation branch line, and a backflow prevention means provided in the communication pipe.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below.
Embodiment 1 FIG.
1 is a schematic configuration diagram showing an entire hot water supply system according to Embodiment 1 of the present invention, and FIG. 2 is an enlarged sectional view showing a heat exchanger in FIG. In FIG. 1, 1 is a primary hot water supply main line, 2 is a secondary hot water supply main line, 3 is a heat exchanger (heat exchange means), and this heat exchanger 3 is a primary side chamber as shown in FIG. 3a and a secondary side chamber 3b, the primary side hot water supply main line 1 is connected to the primary side of the primary side chamber 3a, and the secondary side hot water supply is connected to the secondary side of the primary side chamber 3a. The main pipeline 2 is connected.
[0015]
4 is a hot water supply circulation branch line connected to the secondary side chamber 3 b of the heat exchanger 3, and 5 a and 5 b are hot water supply taps as hot water use means branched from the hot water supply circulation branch line 4 and supplied with hot water. As long as the hot water supply taps 5a and 5b are on the hot water supply circulation branch pipe 4, the number of the hot water supply taps 5a and 5b is not limited, and the installation location is not specified. Reference numeral 6 denotes a circulating pump provided in the hot water supply circulation branch 4 as hot water circulation means for forcibly circulating hot water. In the case of the circulation pump 6 as well, the installation location is on the hot water circulation branch 4. Anywhere.
[0016]
A replenishment water pipe 7 is branched from the primary hot water supply main pipe 1 and connected to the hot water supply circulation branch pipe 4. The replenishment water pipe 7 supplies hot water to the hot water supply circulation branch pipe 4 from the hot water supply main pipe 1. A metering device 8 serving as hot water metering means and a check valve 9 positioned on the secondary side of the metering device 8 are provided. Here, as described above, the check valve 9 located on the secondary side of the water meter 8 on the makeup water pipe 7 is a backflow prevention means for preventing a backflow from the hot water supply circulation branch pipe 4 to the hot water supply main pipe 1. It will be.
[0017]
10 is a communication pipe that communicates the primary side chamber 3a and the secondary side chamber 3b of the heat exchanger 3, and 11 is a check valve provided in the middle of the communication pipe 10. This serves as a backflow prevention means for preventing the hot water from flowing back from the primary side chamber 3a to the secondary side chamber 3b. Here, the check valve 11 is normally configured to open when the differential pressure between the primary side and the secondary side of the connection pipe is equal to or greater than the minimum operating differential pressure. In the first embodiment, The check valve 11 having a value that allows the minimum operating differential pressure of the check valve 11 to be larger than the head of the circulation pump 6 and can prevent an increase in the pipe pressure within an appropriate range is used. The reason is that if the minimum operating differential pressure of the check valve 11 is equal to or less than the head of the circulation pump 6, the check valve 11 opens while the circulation pump 6 is operating, and thus the communication pipe 10 When the hot water in the hot water supply circulation branch 4 flows into the hot water supply main pipe 1 and the outflow is replenished from the makeup water pipe 7 to the hot water circulation branch 4, This is because it is weighed by water meter 8 and more than the actual amount of hot water used.
[0018]
Next, a process for discharging the hot water supply expanded water to the hot water supply main line will be described below. Immediately after draining hot water at the time of periodic inspection and checking again, immediately after refilling, or when leaving for a long time etc., turning off the power of the circulation pump 6 and immediately after turning on the power again at home, The temperature of the hot water in the hot water supply circulation branch 4 is considerably lower than that during normal use.
[0019]
In such a state, since the hot water temperature is equal to or lower than the lower limit set temperature by the control means (not shown), the hot water in the hot water circulation branch line 4 is warmed by starting the circulation pump 6 by the control means. . At this time, the temperature change of the hot water in the hot water circulation branch pipe 4 is considerably larger than the temperature change during normal use, and naturally the volume change of the hot water in the hot water circulation branch pipe 4 is also large. Therefore, the pressure in the hot water supply circulation branch line 4 increases with time.
[0020]
As the pressure in the hot water circulation branch 4 increases, the pressure difference between the pressure in the hot water circulation branch 4 and the pressure in the hot water main pipeline 1 exceeds the minimum operating differential pressure of the check valve 11 of the communication pipe 10. Then, the check valve 11 is opened, and the expanded hot water (excess hot water) is discharged from the secondary chamber 3b of the heat exchanger 3 to the primary chamber 3a.
[0021]
When the hot water temperature reaches the upper limit set temperature (approximately the same as the hot water temperature in the hot water main pipe 1), the circulation pump 6 is automatically stopped by an output control signal from the control means. Thereby, since the volume of the hot water in the hot water supply circulation branch pipe 4 does not expand any more, the check valve 11 can be used when the differential pressure becomes not more than the minimum set differential pressure of the check valve 11. Closes.
[0022]
Embodiment 2. FIG.
FIG. 3 is a schematic configuration diagram showing an entire hot water supply system according to Embodiment 2 of the present invention. The same or corresponding parts as those in FIGS. The second embodiment is different from the first embodiment in that the secondary hot water supply main pipe 2 and the hot water circulation branch pipe 4 are connected by a communication pipe 10, and a check valve is connected to the communication pipe 10. 11 is provided. In the second embodiment, the check valve 11 provided in the communication pipe 10 has a minimum operating differential pressure calculated in the same manner as in the first embodiment, and the discharge process of the hot water supply expanded water is also performed. This is the same as the first embodiment.
[0023]
According to the second embodiment, when the hot water supply system of the prior application (Japanese Patent Laid-Open No. 3-291428) is already used, the heat exchanger 3 is replaced when the hot water supply system according to the second embodiment is improved. It is only necessary to replace some pipes and install a check valve, and there is a great cost advantage. In the second embodiment, the hot water supply circulation branch pipe 4 communicates with the secondary hot water supply main pipe 2 through the communication pipe 10, but the same effect can be obtained even if it communicates with the primary hot water supply main pipe 1. can get.
[0024]
Embodiment 3 FIG.
FIG. 4 is a schematic configuration diagram showing the entire hot water supply system according to Embodiment 3 of the present invention. The same or corresponding parts as those in FIGS. In FIG. 4, 12 is a pressure relief valve provided in the hot water supply circulation branch line 4. That is, in the first embodiment and the second embodiment, the configuration is such that the excess hot water generated in the hot water supply circulation branch pipe 4 is returned to the hot water supply main pipe 1 or 2, but in this third embodiment, the surplus water is supplied. The hot water is discharged to the discharge pipe without returning to the hot water supply main line 1 or 2.
In the third embodiment, when the pipe pressure in the hot water supply circulation branch line 4 becomes equal to or higher than the set operating pressure of the pressure relief valve 12, the pressure relief valve 12 is opened, and the excess hot water is supplied to a drain hopper (not shown). )).
[0025]
In the first embodiment and the second embodiment, the minimum operating pressure of the check valve 11 is calculated. For the calculation, it is necessary to consider the performance of equipment and wear loss of piping and the like. In the third aspect, the maximum internal pressure at which the connected device, piping, etc. function safely can be replaced with the set operating pressure of the pressure relief valve 12 as it is, and the calculation is simple. Also, it is very effective when there is already a drainage hopper nearby or where it can be easily installed.
[0026]
【The invention's effect】
As described above, according to the present invention, an abnormal increase in the pipe pressure can be prevented, and the circulation pump, the branch pipe, the hot water tap, etc. caused by the abnormal increase in the pipe pressure, and the damage There is an effect that damage due to water leakage can be prevented. Moreover, there is an effect that an abnormal discharge of hot water can be prevented, and a hot water supply system can be obtained which has no danger of occupants being burned.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a hot water supply system according to a first embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view showing the heat exchanger in FIG.
FIG. 3 is a schematic configuration diagram showing a hot water supply system according to a second embodiment of the present invention.
FIG. 4 is a schematic configuration diagram showing a hot water supply system according to Embodiment 3 of the present invention.
[Explanation of symbols]
1, 2 Hot water supply main pipeline 3 Heat exchanger (heat exchange means)
3a Primary side chamber 3b Secondary side chamber 4 Hot water supply circulation branch line 5a, 5b Hot water tap (use of hot water supply)
6 Circulation pump (Hot water supply circulation means)
7 Supply water pipe 8 Water meter (Measuring means for hot water supply)
9 Check valve (backflow prevention means)
10 Communication pipe 11 Check valve (Backflow prevention means)
12 Pressure relief valve

Claims (2)

(A) a hot water supply main line for supplying hot water,
(B) a hot water supply circulation branch line for supplying hot water to the hot water use means;
(C) a replenishment water pipe for branching from the hot water supply main line and connected to the hot water circulation branch line for supplying hot water;
(D) heat exchanging means composed of a primary side chamber connected to the hot water supply main pipeline and a secondary side chamber connected to the hot water circulation branch pipeline;
(E) Hot water supply water circulation means installed in the hot water supply circulation branch pipe;
(F) hot water metering means installed in the makeup water pipe;
(G) In a hot water supply system comprising surplus hot water discharge means for discharging surplus hot water from the hot water circulation branch pipe and / or the heat exchange means ,
The surplus hot water discharge means is
(H) a communication pipe communicating the primary side chamber and the secondary side chamber of the heat exchange means;
(I) backflow prevention means installed in the communication pipe;
Hot water supply system characterized in that it consists of. (A) a hot water supply main line for supplying hot water,
(B) a hot water supply circulation branch line for supplying hot water to the hot water use means;
(C) a replenishment water pipe for branching from the hot water supply main line and connected to the hot water circulation branch line for supplying hot water;
(D) heat exchanging means composed of a primary side chamber connected to the hot water supply main pipeline and a secondary side chamber connected to the hot water circulation branch pipeline;
(E) Hot water supply water circulation means installed in the hot water supply circulation branch pipe;
(F) hot water metering means installed in the makeup water pipe;
(G) In a hot water supply system comprising surplus hot water discharge means for discharging surplus hot water from the hot water circulation branch pipe and / or the heat exchange means,
The surplus hot water discharge means is
(H) a communication pipe communicating with the hot water supply main line and the hot water circulation branch line;
(I) feeding water system that is characterized by comprising a reverse flow preventing means installed in the communicating pipe.

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