JPS63286656A - Hot-water supplier - Google Patents

Abstract

PURPOSE:To permit the control of a supplying hot-water temperature as well as a supplying hot-water flow rate within a wide range, by a method wherein a hot-water supplying circuit is constituted by a heating passage and a bypass circuit while the amount of generating heat is controlled in the heating passage so as to obtain a delivered hot-water temperature slightly higher than a set temperature and the mixing amount of cool water is controlled in the bypass passage so that a mixed hot-water temperature becomes a set temperature. CONSTITUTION:Supplied water is branched to flow through a heating passage 3 and a bypass passage 4. An inflow water temperature Tc is detected by a water temperature detector 7 and a flow rate QH is detected by a flow rate detector 9, a heat amount control unit 13 calculates the signal of a temperature setter 11 as well as the amount of gas for burning in a heating device 5 from the data of these detectors to output a signal to a capacity control device 6. Water, flowing through the heating passage 3, is heated in a heat exchanger 2 to a delivery hot-water temperature, slightly higher than a set temperature Ts. Thereafter, cool water is mixed and a hot-water temperature TM after mixing is detected by a hot-water temperature detector 8 to operate a water amount regulating valve 10 by a water amount control unit 14 so that the hot-water temperature TM becomes equal to the set temperature TS.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a water heater, particularly a water heater for domestic use.

(Conventional technology) Conventional water heaters heat water flowing through a heat exchanger,
In some cases, the amount of gas is increased or decreased to produce hot water at a set temperature, or as shown in Japanese Utility Model Application Publication No. 58-120443, hot water at a high temperature (e.g. 80°C) is made in a heat exchanger, and hot water at a temperature lower than that is made in a heat exchanger. When pouring hot water, mix it with cold water and bring it to the set temperature.

(Problem to be Solved by the Invention) However, in the former method, all of the hot water supply flow passes through the heat exchanger, so the passage delay is large and a large amount of hot water cannot be dispensed. The vessel was to become larger.

Furthermore, when hot water is tapped at a low temperature, drainage is generated in the heat exchanger, causing a problem of corrosion of the heat exchanger. On the other hand, in the latter case, the flow rate of the heat exchanger is small and there is no risk of drain generation due to the hot water being tapped out at a high temperature, but there is a problem in that the desired hot water tapping temperature cannot be obtained depending on the conditions. In other words, in the summer (high water inlet temperature), if the set temperature is low with the tap restrictor (low water output), for example, when the inlet water temperature is 20°C, tin of 40@C is 51! / minute, the lowest flow rate that can flow to the heat exchanger ff1 (for example, 2
．． 5j! 5i! / minutes of water must be mixed. However, since the total flow rate is only 51/min, the amount of water to be mixed can only flow 2.5 J/min, and therefore hot water at 40°C cannot be obtained.

SUMMARY OF THE INVENTION The present invention aims to solve the above-mentioned problems and to provide a water heater that has a smaller heat exchanger, a large amount of hot water discharged, and prevention of drainage, as well as a wider range of hot water supply temperature and hot water flow rate.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a hot water supply circuit configured with a heating path passing through a heat exchanger and a bypass path parallel to the heat exchanger, and A heating device that heats, a capacity control device that controls the amount of heat generated by the heating device, a water temperature detector that detects the temperature of the water supply, a hot water temperature detector that detects the temperature of the mixed water, and a water temperature sensor that controls the amount of water supplied to the heat exchanger. A flow rate detector for detecting water flow, a water flow control valve provided in the bypass passage for controlling water flow, a temperature setting device, and a capacity control device operated by signals from the water temperature sensor, flow rate sensor, and temperature setting device. It is characterized by comprising a temperature detector and a control circuit section that operates a water flow control valve based on a signal from a temperature setting device.

(Function) The temperature of hot water discharged from the heat exchanger is controlled by feedforward control of the calorific value of the heating device.

The deviation from the set temperature is corrected by increasing or decreasing the amount of cold water mixed through feedback control. Therefore, even in the case of low-temperature, small-quantity dispensing, the flow rate can be reduced to a level slightly higher than the minimum flow rate to the heat exchanger.

(Example) The drawing shows an example of the present invention, and (1) shows a heat exchanger (2).
) and a bypass path (4) parallel to the heat exchanger (2). (5)
is a heating device such as a burner that heats the heat exchanger (2), (6
) is a capacity control device such as a gas proportional valve that controls the calorific value of the heating device (5). (7) is a water temperature detector installed on the water inlet side of the hot water supply circuit (1) to detect the temperature of the water supply;
8) is a hot water temperature detector installed on the hot water outlet side of the hot water supply circuit (1) to detect the mixed hot water temperature. (9) is a flow rate detector that detects the flow rate to the heat exchanger (2), and is arranged in the heating path (3). (10) is a water flow control valve provided in the bypass passage (4) to control the flow of bypass water. (11) is a temperature setting device. (12) is the control circuit section, water temperature detection fl
(7), the flow rate detector (9), and the temperature setting device (11) to operate the capacity control device (6).
3), and a water flow control unit (
14).

The operation of the above configuration will be explained. The supplied water is divided into a heating path (3) and a bypass path (4). Heating path (
3), the water temperature detector (7) detects the inlet water temperature (Tc), the flow rate detector (9) detects the flow rate (Qn), and the heat amount control unit (1
3) send a signal to The heat quantity control unit (13) uses these data together with the signal from the temperature setting device (8) to set the heating device @ (5).
calculates the amount of gas to be combusted and sends a signal to the capacity control device (6) to flow that amount of gas. Then, the water flowing through the heating path (3) is heated by the heat exchanger (2), and in anticipation of the cold water mixture, the water is brought to a temperature slightly higher than the set temperature (Ts). The water temperature (TM) of the mixed amount is detected by the hot water temperature detector (8), and the water volume control unit (14) controls the water volume control valve (10) so that TM: T5 is mixed with the treated cold water. calculates the opening degree of and operates the water flow control valve (10). for example,
When discharging hot water for 51/min at Ts=40℃, the heating path (3
), and assuming that the incoming water temperature Tc = 20°C, the heating path (3) will have a heating time of 3.3117 minutes, and the bypass path (
4) is 1.77! / Just divert it.

Therefore, the capacity control device (6) flows the amount of gas corresponding to the hot water output at the gloss temperature, and the water amount control valve (10) controls the amount of bypass water to 1.7.
1! /minute.

Further, when hot water is to be discharged at a high temperature, the water amount control valve (10) may be fully opened to allow hot water at the hot water temperature to be discharged from the heating path (3) as it is.

Furthermore, if it is within the capacity of the heating device (5), heat at the maximum calorific value and then fully open the water flow control valve (10).
It is also possible to dispense a large amount of hot water for about 1817 minutes at 0°C.

Furthermore, the temperature of the hot water discharged from the heat exchanger (2) is above the low temperature corrosion limit due to condensate, and no condensate is generated.

(Effects of the Invention) As described above, the present invention configures a hot water supply circuit with a heating path and a bypass path, and controls the amount of heat generated in the heating path so that the hot water temperature is higher than the set temperature in anticipation of the amount of cold water mixed. Since the amount of cold water mixed from the bypass path is controlled so that the mixed water temperature reaches the set temperature, both the hot water temperature and hot water supply flow rate can be controlled over a wide range. Furthermore, compared to a water heater with only a heating path without a bypass path, the heat exchange hot water temperature can be kept relatively high even at 11 o'clock in the capacity, preventing low-temperature corrosion of the heat exchanger, and within the capacity of the heating device. It has a variety of excellent effects, such as making it possible to carry out large-scale exits.

[Brief explanation of drawings]

FIG. 1 is an overall circuit diagram of the present invention. FIG. 2 is a block circuit diagram of the control circuit section. (1) Hot water supply circuit (2) Heat exchanger (3) Heating path (4) Bypass path (5) Heating device (6) Capacity control device (7) ... Water temperature detector (8) ... Hot water temperature sensor (9) ... Flow rate detector (10) ... Water flow control valve (11) ... Temperature setting device (12)・Control circuit section

Claims (1)

[Claims] a hot water supply circuit configured with a heating path passing through a heat exchanger and a bypass path parallel to the heat exchanger; a heating device that heats the heat exchanger; and a capacity control device that controls the amount of heat generated by the heating device. , a water temperature detector for detecting the water supply temperature, a hot water temperature detector for detecting the mixed water temperature, a flow rate detector for detecting the amount of water supplied to the heat exchanger, and a water amount adjustment provided in the bypass path for controlling the amount of water. a valve, a temperature setting device, and a control circuit unit that operates a capacity control device based on signals from the water temperature detector, flow rate sensor, and temperature setting device, and operates a water flow control valve based on signals from the hot water temperature sensor and temperature setting device; A water heater characterized by comprising: