JPS63311039A - Hot water feeding control apparatus - Google Patents

Abstract

PURPOSE:To improve hot water feeding characteristic and improve convenience in use by a method wherein a hot water set temperature is made as a function of a set temperature and a water feeding temperature and the hot water feeding temperature is controlled under a feed-forward control in such a way as a mixing ratio of hot water and cold water is made constant even if a set temperature or a feeding cold water temperature is varied. CONSTITUTION:Water to be fed is divided into a heating passage 3 and a bypass passage 4. A cold water feeding temperature TC is detected by a cold water temperature sensor at the heating passage 3, a flow rate QH is detected by a flow rate detector 9 and then a signal is sent to a calorie control part 13. An amount of gas G to be ignited by a heating device 5 is calculated it a calorie control part 13 in response to a signal from a temperature setting unit 8 and these data and then a signal is sent to a capacity control device 6. Water flowing through the heating passage 3 is heated by a heat exchanger 2, set to a fed-out hot water temperature TH slightly higher than a set temperature TS in view of a cold water mixed part. That is, the water is heated under a feed-forward control. Then, it is mixed with cold water and a hot water temperature TM after mixing is detected by a hot water temperature detector 8 and the degree of opening of an amount of water adjusting valve 10 is calculated in such a way as a relation of TM=TS can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a hot water mixing type hot water supply control device, and improves hot water output characteristics by controlling the hot water side temperature so that the hot water mixing ratio is always constant. The present invention relates to a scale and a hot water supply control device that is easy to use.

(Prior Art) Generally, in a hot water mixing type hot water supply control device that mixes water and hot water to obtain a desired hot water outlet temperature, a method is adopted in which the hot water side outlet temperature is set to a constant high temperature. (Jitsukai 58-
(Refer to Publication No. 120443) In such a conventional method, feedback control is adopted in which the hot water mixing valve is controlled while comparing the mixed outlet temperature TM and the set temperature TS.
When the temperature changes, the hot water mixing valve is driven to make it match the set temperature TS.

(Problems to be Solved by the Invention) In this conventional method of setting the hot water outlet temperature at a constant high temperature, the hot water mixing ratio changes every time the set temperature changes.

In other words, the hot water temperature from the heat exchanger (= hot water side hot water temperature) TH
, the inlet water temperature To, the hot water flow rate QH1, the mixed hot water output temperature TM, the hot water output amount QM, and the heating capacity G. QM day QH-
1-QC...(2) QMTH-T.

The following formula holds true.

For example, in each of the above equations (1), (2), and (3), hot water side outlet temperature TH = 80°C, set temperature TS = TM = 38°C, water inlet temperature TO = 15°C, hot water output amount QM = lC1// m i
Substituting each as n, the hot water side flow rate Q H = 3.
541 / ra L +1, bypass water amount QO
=6.461/min. Also, the set temperature T S = T
When M is changed to 45℃, the hot water side flow rate QH-4.621
/min% bar4. Water amount Q Q=5.381/min. In other words, the hot water mixing ratio is QH/QMヰ0.354TS=4 when TS=38℃
At 5°C, it changes as QH/QM=0.462.

When the set temperature TS changes, the mixing ratio must also be changed, but since the mixing ratio is controlled by feedback control, a control delay occurs, causing a delay in the response of the hot water mixing valve, and on top of that, when changing the ratio, Therefore, the response is slow, such as the need to control the hot water mixing valve, which takes a long time to operate.
There is a problem that the hot water characteristics deteriorate.

This invention was made in consideration of the above circumstances, and
The purpose of this invention is to provide a hot water mixing control device for a water heater that improves the ease of use by controlling the hot water temperature so that the hot water mixing ratio is always constant, thereby improving the hot water output characteristics. be.

[Means for solving problems]

In order to achieve the above object, the hot water supply control device according to the present invention includes a water temperature detector that detects the incoming water temperature, a temperature setting device that sets the mixed outlet temperature, and receives the outputs of the water temperature detector and the temperature setting device. and a hot water side temperature setting means for setting a hot water side set temperature that has a predetermined functional relationship with these; With this configuration, when the set temperature TS or the inlet water temperature To is changed, the hot water mixing ratio remains constant. The hot water side temperature can be changed to control the desired hot water outlet temperature TS, and deterioration of hot water outlet characteristics due to response delay of the hot water mixing valve can be prevented.

〔Example〕

The drawings show an embodiment of the present invention, in which (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), and (6) is a capacity control device such as a gas proportional valve that controls the amount of heat generated by the heating device (5). (7) is a water temperature detector installed on the inlet side of the hot water supply circuit (1) to detect the temperature of the supplied water, and (8) is a water temperature detector installed on the outlet side of the hot water supply circuit (1) to detect the mixed water temperature. It is a temperature detector. (9) is a heat exchanger (
This is a flow rate detector that detects the flow rate to 2), and is arranged in the heating path (3). CLQ is a water f control valve provided in the bypass passage (4) to control the amount of bypass water. α is a temperature setting device. (b) is the control circuit section, and the water temperature detector (7
], a heat quantity control unit α4 that operates the capacity control device (6) based on the signals from the flow rate detector (9) and the temperature setting device U, and a heat quantity control unit α4 that operates the capacity control device (6) based on the signals from the flow rate detector (9) and the temperature setting device αυ; A hot water side temperature setting means αQ that sets a hot water side set humidity that has a predetermined functional relationship, and a water flow rate control unit σXuan that operates a water flow rate adjustment valve based on signals from a temperature setting device U and a hot water temperature detector (8). Built-in.

The control circuit section (b) is configured to control the set temperature T of the temperature setting device a.
S and the inlet water temperature T detected by the water temperature detector (7).

Based on this, for example, the hot water side set temperature TS is set based on the following equation (4), and the opening degree of the gas proportional valve (6) is controlled so that the hot water side outlet temperature TH matches this set value. It is configured.

TS=f(Ts,TCri=ni-TS+(1-K)・To
(4) The operation of the above configuration will be explained. The supplied water is divided into a heating path (3) and a bypass path (4). In the heating path (3), a water temperature detector (7) measures the inlet water temperature To, and a flow rate detector (9) measures the flow rate QH. Detection and heat control part α
Send a signal to J. The heat quantity control unit C13 uses a humidity setting device (8
), the gas amount G to be combusted by the heating device (5) is calculated from these data, and a signal is sent to the capacity control device (6) to cause the gas amount to flow. 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 outlet temperature is set to T, i (a little higher than the set temperature TS. That is, TH = TS'). Then, the gas amount G is calculated from the above equation (1) and heated by feedforward control.After that, it is mixed with cold water, and the hot water temperature TM after mixing is detected by a hot water temperature detector (8). Then, the water flow control unit q41 calculates the opening degree of the water flow control valve αQ so that TM=TS, and operates the water flow control valve CIG.

By the way, suppose that the set temperature TS is changed during hot water supply. As mentioned above, the set temperature TS on the hot water side is determined by equation (4), and now T H = T S , T)9P-TS, so substituting these into equation (3) gives QHI M K . , the hot water mixing ratio will always remain constant regardless of the set temperature. Moreover, this similarly remains constant even if the inlet water temperature TC changes.

Note that K can be arbitrarily selected as an appropriate value.

〔Effect of the invention〕

As described above, according to the present invention, the set temperature on the hot water side is made a function of the set temperature and the inlet water temperature, and even if the set temperature and the inlet water temperature change, the hot water mixing ratio is kept constant, and the capacity control device feedforwards. Since the configuration is configured so that the hot water outlet temperature is controlled by the control, even if the set temperature is changed, the capacity control side, which has a quick response time, will respond, and the hot water mixing ratio side, which has a slow response time, will hardly need to be operated. , the mixed hot water temperature can be controlled without any control delay, the hot water tap characteristics can be improved, and the ease of use can be increased.

[Brief explanation of the drawing]

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) 0. , bypass path (5)...heating device (6)...capacity control device (7n...water temperature detector (8)...hot water temperature detector (9)...flow rate detector σq・...Water volume super saving...Temperature setting device 02)...Control circuit part σ...Hot water side temperature setting means

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, a water temperature detector that detects the incoming water temperature, and a mixed outlet water temperature. a hot water side temperature setting means for receiving the outputs of the water temperature detector and the temperature setting device and setting a hot water side set temperature that has a predetermined functional relationship with these; A hot water supply control device comprising: a capacity control device that controls the amount of heat generated by the heating device so as to match the temperature.