JPH0148474B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a constant pressure and temperature device in a heat supply system, and uses various types of hot water such as hot springs, geothermal water, industrial heat drainage, etc., depending on the topography, size, and use of the hot water. situation,
In other words, regardless of conditions such as the disparity in usage between peak load times (peak load times) when the daily amount of hot water used is at its maximum and other peak load times,
This relates to a constant-pressure and constant-temperature device for a hot water supply system that has a mechanism that can always supply hot water at a constant temperature and pressure, and that also allows the diameter of the hot water circulation pipe to be reduced to reduce construction costs. It is.

As shown in Figure 1, the amount of hot water used per day varies depending on the time of day, and in particular, the amount used around 6:00 p.m. during peak load times16 is significantly higher than during non-peak load times17. It jumps up by the difference in . For this reason, in the conventional hot water supply system, the flow rate in the thermal circulation pipe is set to 2 to 2.5 times the amount used during peak load to overcome the load during peak load.
Moreover, the temperature is kept constant. Therefore, the diameter of the pipeline inevitably increases, and the power of the circulation pump must accordingly increase. Therefore, this naturally increases construction costs, and there is also the disadvantage that the pressure within the pipeline is not always constant.

Therefore, this invention was created in view of the above-mentioned drawbacks, etc., and its gist is a hot water storage tank, a circulation pump that sends out hot water from the hot water storage tank, and a supply of hot water to the place where it is used. In a hot water supply system consisting of a hot water circulation pipe that circulates a predetermined amount of hot water and flows it back into the hot water tank in order to maintain a constant temperature of the hot water supplied, the hot water discharge port of the circulation pump Nearby, the pipe is branched into a pipe for supply and circulation of hot water and a return pipe for returning hot water directly to the hot water storage tank, and the inlet side of the pipe for supply circulation is connected to the internal pressure of the hot water. A pressure detection device is installed to detect the flow rate of hot water, and a flow rate adjustment valve is installed in the return pipe, and a flow rate adjustment valve is installed in the return pipe, and near the end of the circulation pipe to the hot water storage tank in the supply circulation pipe, the flow rate of hot water that has been circulated is installed. A flow meter and a flow rate regulating valve are installed to measure the amount of hot water, and regardless of the amount of hot water used, the value of the flow meter near the end of the flow of the circulation pipe is adjusted to a predetermined amount of heat necessary to maintain the temperature constant. The flow rate adjustment valve near the end of the circulation pipe is automatically controlled to maintain only the flow rate of water, and the return pipe is automatically controlled to maintain the internal pressure detected by the pressure detection device at a constant pressure. The present invention consists in providing a control mechanism that automatically controls the flow rate regulating valve.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

That is, the reference numeral 1 shown in the figure is a hot water storage tank, which stores hot water such as hot spring water, geothermal water, industrial heat waste water, etc. through a source heat water flow pipe 2 from the outside.

A circulation pump 3 that sends out hot water from the hot water storage tank 1 is connected to the hot water storage tank 1, and the circulation pump 3 has a hot water circulation pipe 5 that can supply the hot water sent out to various places 4 where it is used. connected. This hot water circulation pipe 5 has a flow rate near the discharge port 6 of the circulation pump 3 at a usage amount A of 16 at peak load.
and the amount α of hot water to be circulated to keep the supply temperature of hot water constant (A+α), and A is consumed in the hot water circulation pipe 5, and the flow of the hot water circulation pipe 5 is This is a combination of the pipe diameter and the thickness of the heat insulating material determined by hydraulic/calorific calculations performed under conditions such that the flow rate at the end portion 10 is α. However, A≫α.

However, the hot water circulation pipe 5, which has the pipe diameter and heat insulating material thickness determined by the above calculation, has a roughness coefficient in the pipe, characteristics of the circulation pump 3,
Due to uncertain factors such as changes in the usage amount A, the pressure within the hot water circulation pipe 5 is not necessarily constant, and the flow rate α at the flow end portion 10 of the hot water circulation pipe 5 is also not always constant.

Therefore, a branch pipe is formed in the vicinity of the discharge port 6 of the circulation pump 3, one of which is a hot water circulation pipe 5 for supplying hot water, and the other is a return pipe 7 that directly returns hot water to the hot water storage tank 1. The former hot water circulation pipe 5 is equipped with a pressure detection device 9 for detecting the pressure inside the pipe, and the latter return pipe 7 is equipped with a pressure detection device 9 to keep the pressure inside the hot water circulation pipe 5 constant at all times. , an electric flow rate adjustment valve 8 is provided to adjust the flow rate in the return pipe 7.

In addition, near the end portion 10 of the hot water circulation pipe 5 where the hot water returns to the hot water storage tank 1, there is a flow rate α of the returned hot water to always keep the hot water supply temperature constant. A flow meter 11 and an electric flow rate adjustment valve 12 are provided to control the flow rate so that the following flow rate is controlled.

In order to adjust the flow rate to keep the internal pressure of the hot water circulation pipe 5 constant regardless of the amount of hot water used, and to make the supply temperature constant, a flow end portion 10 of the hot water circulation pipe 5 is provided. An automatically controllable control mechanism 13 such as a computer is provided to automatically control the flow rate adjustment so as to fix the flow rate at α.

Next, explaining the operation, hot water stored in the hot water storage tank 1 is sent out by the circulation pump 3. This hot water is then supplied to the hot water usage locations 4 located at various locations through the hot water circulation pipe 5 as shown by the arrow lines in Figure 2, and the hot water that remains after being used is Furthermore, the hot water is allowed to flow through the hot water circulation pipe 5 from the flow end 10 of the circulation pipe 5 into the hot water storage tank 1 again. If it is determined that the flow rate is greater than a predetermined amount, the control mechanism 13 automatically sends a signal to close the electric flow rate adjustment valve 12 to adjust the flow rate to a predetermined amount, and vice versa. When the returned amount is less than a predetermined amount, the control mechanism 13 is activated in the same manner as described above to open the electric flow rate adjustment valve 12.
automatically sends a signal. Therefore, the amount of hot water returned to the hot water storage tank 1 is always constant, and as a result, the supply temperature of hot water is constant.

However, with only the above-described control, although the flow rate of hot water returning to the hot water storage tank 1 is constant, the pressure inside the hot water circulation pipe 5 varies depending on the amount of hot water used.
Therefore, the pressure inside the pipe is measured by a pressure detection device 9 installed in the hot water circulation pipe 5 near the discharge port 6 of the circulation pump 3, and if the pressure inside the pipe becomes larger than a predetermined value, the return The control mechanism 13 automatically sends a signal to open the electric flow control valve 8 of the pipe 7, and a portion of the hot water discharged by the circulation pump 3 is sent directly to the hot water tank 1 to reduce and adjust the pressure inside the pipe. Conversely, when the pressure inside the pipe becomes smaller than a predetermined value, the control mechanism 13 automatically sends a signal to close the electric flow rate adjustment valve 8.
The discharge pressure of the circulation pump is maintained as it is in the hot water circulation pipe 5.
The pressure inside the pipe is always kept constant at a predetermined value.

In addition, in the figure, 14 is a flow meter that measures the flow rate of hot water near the discharge port 6, and 15 is a flow meter 1 from the control mechanism 13.
1. Pressure detection device 9, each electric flow rate adjustment valve 8, 12
This is a signal cable that is wired to.

Since this invention is constructed as described above,
The hot water sent out from the hot water storage tank 1 is always supplied at a constant pressure to the place 4 where hot water is used, and the supply temperature can also be kept constant, so a stable amount of heat can be supplied to the users, and furthermore, The pipe diameter of the hot water circulation pipe 5 can be made to produce results consistent with hydraulic and calorific calculations, and therefore, the pipe diameter can be made thinner, reducing construction costs and reducing the pipe size. This allows the amount of heat dissipated from the road to be minimized.

As explained above, the present invention provides a hot water storage tank 1
In a hot water supply system consisting of a circulation pump 3 and a hot water circulation pipe 5 that circulates and supplies hot water,
The pipe 5 near the hot water outlet 6 of the circulation pump 3
is branched into a return pipe 7 and a pipe line for hot water supply circulation, and each electric Flow rate regulating valves 8 and 12 are provided, and a flow meter 11 is also provided near the flow end 10 of the circulation pipe 5, and a pressure sensor is installed in the branched pipe for supplying and circulating hot water. A device 9 is installed to keep the value of the flow meter 11 near the flow end 10 of the circulation pipe 5 constant regardless of the amount of hot water used.
In order to keep the pressure inside the pipe detected by the pressure detection device 9 constant, each electric flow rate adjustment valve 8,
12 is controlled by the control mechanism 13, it is possible to supply a stable amount of heat from hot water to the user, and the pipe diameter can be made as thin as possible, thereby reducing construction costs and power costs. This provides excellent effects such as minimizing heat loss from the hot water circulation pipe 5.

[Brief explanation of drawings]

FIG. 1 is a graph showing the usage of hot water per hour in one day, and FIG. 2 is an overall schematic piping system diagram showing one embodiment of the present invention. 1... Hot water storage tank, 2... Source hot water inflow pipe, 3...
Circulation pump, 4... Place of use, 5... Hot water circulation pipe, 6... Discharge port, 7... Return pipe, 8...
...Electric flow rate adjustment valve, 9...Pressure detection device, 10...
...Flow end portion, 11...Flowmeter, 12...Electric flow rate adjustment valve, 13...Control mechanism, 16...At peak load, 17...At non-peak load.

Claims (1)

[Claims] 1. A hot water storage tank, a circulation pump that sends out hot water from the hot water storage tank, and a circulation pump that supplies the hot water sent out to the place where it is used, and that circulates a predetermined amount of hot water to keep the temperature of the hot water constant. In a hot water supply system consisting of a hot water circulation pipe that flows into a hot water storage tank, near the hot water outlet of the circulation pump, the pipe is connected to a pipe for supplying and circulating hot water and a pipe that supplies heat directly to the hot water storage tank. A pressure detection device is installed on the inlet side of the pipeline for supply circulation to detect the pressure inside the pipe of hot water, and a flow rate adjustment valve is installed in the return pipe to further supply water. A flow meter and a flow rate adjustment valve are installed near the end of the circulation pipe leading to the hot water storage tank to measure the flow rate of the hot water that has been circulated, regardless of the amount of hot water used. First, the flow rate adjustment valve near the end of the circulation pipe is automatically operated so that the value of the flow meter near the end of the flow of the circulation pipe is set to only the flow rate value of a predetermined amount of hot water necessary to maintain the temperature constant. control,
and a constant pressure and constant temperature in a hot water supply system, characterized in that a control mechanism is provided that automatically controls a flow rate adjustment valve of a return pipe so as to always keep the pressure inside the pipe detected by the pressure detection device at a constant pressure. Device.