JPS58205027A - Supplying apparatus of hot water - Google Patents

Abstract

PURPOSE:To expand a range of control by a constitution wherein constant flow valves are provided on the supply side of hot-water supply units and differential pressure control valves operated by a differential pressure according to the quantity of supplied water are provided on the supply side of the hot-water supply units except one unit in a hot-water supply apparatus comprising a plurality of small-bore hot-water supply units. CONSTITUTION:When a hot-water supply tap 3 is opened, service water is made to flow, together with a heating medium, to a hot-water supply unit A by a water supply load since the water passage of a hot-water supply unit B is stopped by a differential pressure control valve 8, and thereby hot-water supply is conducted. When the water supply load exceeds a value set for a constant flow valve 7, the differential pressure control valve 8 operates to open the water passage of the hot-water supply unit B so as to flow the service water and the heating medium through the unit B, whereby the supply of hot water is conducted from the unit B. At this time, the control of the temperature of the hot-water supply unit B is made on the quantity of water obtained by subtracting the maximum quantity of the hot-water supply of the unit A from the water supply load. Thus, the hot water from the two hot-water supply units A and B is mixed to be supplied, and thereby the range of control can be expanded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a water heating system comprising a plurality of small-diameter water heaters.

As a water heater when the hot water supply load fluctuates over a wide range,
Instead of using a large-capacity water heater (with a large hot water output) and controlling the hot water temperature using an electronic controller and three-way valve, we have installed multiple small water heaters connected in parallel and controlled by an automatic temperature control valve. A system has been proposed that uses high output power. The latter method does not require a power source and is relatively inexpensive compared to the former method, so it tends to be used more frequently, but it has the following problems. In other words, the load on each water heater is given in inverse proportion to the water flow resistance of each device, so if the load is large, it is possible to control the hot water temperature, but if the overall load is small, each device (If the water heaters are configured using the same water heater, the load on each water heater will be 1/1 of the total number of water heaters).

If the control range of each individual device is exceeded, control becomes uncontrollable and unstable.

The purpose of this invention is to eliminate the drawbacks of the prior art described above,
An object of the present invention is to provide an improved water heater with a wide range of controllability.

According to the present invention, a constant flow valve is provided on the water supply side of each water heater to prevent overload of the water heater alone, while differential pressure control is provided on the water supply side of the water heater to which the next load is applied. This can be achieved by installing a valve and controlling the number of units depending on the load.

The present invention will be described below with reference to the drawings. FIG. 1 shows a case where two small-sized water heaters with the same output are used to form a large-output water heater.

Each of the water heaters A and B consists of a heat exchanger 1 and a temperature control valve 6 provided on the heat medium outlet 5 side thereof. The temperature control valve 6 is actuated by a detection signal from a temperature sensor set on the hot water supply port 6 side of the heat exchanger 1, and adjusts the flow rate of the heat medium to the heat exchanger 1 to reach a set hot water temperature, e.g. It has a control function that allows a temperature of 60°C to be obtained. Therefore, water is supplied to each of the water heaters A and B, and the temperature of the hot water can be automatically controlled.

Water heaters A and B having such a configuration are connected and arranged in parallel,
Although twice the amount of hot water can be supplied, a constant flow valve 7 is installed on the water supply side of each water heater A and B, so that even if the water supply pressure fluctuates, the maximum flow rate within the respective control range is maintained. is now available.

However, the differential pressure control valve 8 is located on the water supply port 2 side of one water heater B.
is installed. The pressure guide pipe of the differential pressure control valve 8 is connected to a location where a differential pressure depending on the amount of water supplied is generated, for example, a water supply port to a water heater and a hot water supply port.

The operating setting value of this differential pressure control valve 8 is the same value as the differential pressure that occurs between the two points when the flow rate of the constant flow valve 7 setting value flows, but it may be a value lower than that. do not have.

When six water heaters are connected in parallel, a constant flow valve 7 and a differential pressure control valve 8 are installed on the water inlet side of the sixth water heater as in the case of the second water heater B. Ru. The same applies to subsequent additional water heaters.

In such a configuration, when the hot water supply port 6 is opened and the hot water supply load increases, since the water supply channel of the water heater B is cut off by the differential pressure control valve 8, clean water flows to the water heater A and a heat medium flows. ,
Hot water supply starts with the temperature controlled.

Here, the temperature control of water heaters A and B produces hot water of 3L/mII.
If it is unstable up to +, the hot water temperature is 3t/mi.
It is unstable up to n, but stable from then on to the set value by the constant flow valve 7. During this time, there is a difference between the water supply port of water heater A and the hot water supply port: E71 due to fluid resistance.
□73. χ1□・-FErrj;, #@a B o-
! It is guided by B'Jt1#*8.

If the hot water supply load exceeds the set value of the constant flow valve 7, the differential pressure control valve 8 is activated and the water supply channel of the water heater B is opened. , hot water is also supplied from water heater B.

In this case, water heater B uses water heater A based on the hot water supply load at that time.
The temperature is controlled based on the amount of water supplied after subtracting the maximum amount of hot water supplied, and the hot water supplied is a mixture of hot water from both water heaters A and B.

Here, if the amount of hot water supplied by water heater B is 5 t/mm or less, the temperature of the hot water supplied from water heater B is unstable, but the hot water is mixed with a large amount of hot water from water heater A, so The temperature change is absorbed by the hot water from water heater A and does not disturb the temperature of the hot water supply for the load. This means that if the maximum flow rate of water heaters A and B is 15 t/m each, the stable range is 6 to 50 t/m (3 to 50 t/m in the case of 3 water heaters).
45t/m1q), and 6 to 30 L/mm when two units are simply connected in parallel (9 to 45t/m for six units)
=) This means that the control range of hot water temperature has been expanded compared to ().

Incidentally, the standard output is 50. When we look at the change in hot water temperature when we change the amount of hot water in a case where we use two small water heaters with a capacity of 10 o, 000 kon/h using two small water heaters of ]4//h, we can see that According to the invention, if two units are simply connected in parallel as shown by the line T in Figure 2 (
It can be seen that the stable range is wider than that shown in Figure 6).

In this case, the standard conditions for 5 o, o OOx,, g/b are: water supply temperature 5°C, water supply amount 15.2 L/mm, hot water supply temperature 60°C, heating medium population temperature 90°C, heating medium outlet temperature 40℃
, the heat medium flow rate' is 6.6 t/mjn.

As is clear from the above explanation, the device according to the present invention limits the maximum load per unit using a constant flow valve, and detects the differential pressure at load using a differential pressure control valve to operate the next water heater. This not only makes it possible to control the number of units in operation according to the load, but also has the advantage of widening the hot water temperature control range.

In the previous example, water heaters with the same output were used, but it is also possible to combine water heaters with different outputs by selecting a constant flow valve or differential pressure control valve.

Further, the present invention can also be applied to a case where a plurality of gas instantaneous water heaters are configured to control the main burner to ignite when a hot water supply load is applied.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an example of a water heater according to the present invention;
FIG. 2 is a graph showing the control characteristics of an example of the water heater according to the present invention, and FIG. 6 is a graph showing the control characteristics of a conventional water heater. 1: Heat exchanger, 2: Water supply inlet, 6: Hot water supply inlet, 4: Heat medium population, 5: Heat medium outlet, 6: Temperature control valve, 7: Constant flow valve, 8: Differential pressure control valve, A and B: Water heater. Agent Patent Attorney Fujio Sato 7-5n
Neichi
day←
~Josa 71 Hitachi Cable Co., Ltd., 2-1-2 Marunouchi, Chiyoda-ku, Tokyo Applicant Hitachi Cable Co., Ltd. 136-2, 2-1 Marunouchi, Chiyoda-ku, Tokyo

Claims (1)

[Claims] 1. In a water heater that consists of a plurality of small water heaters connected and arranged in parallel, each of the water heaters has a constant flow valve on its water supply side, and the water supply sides of the remaining water heaters except for one have a water supply valve. A hot water supply device characterized by being provided with a differential pressure control valve that operates based on a differential pressure depending on the amount of water.