JPH02213645A - Instantaneous hot water boiler - Google Patents

Abstract

PURPOSE:To enable hot water of desired temperature to be used within a short period of time by a method wherein a hot water storing and temperature keeping container is arranged at a downstream side of a heat exchanger, a return flow system having pumps arranged at a downstream side of the hot water storing and temperature keeping container and at an upstream side of a heat exchanger is constructed and then some valves are arranged at proper locations in the return flow system. CONSTITUTION:As a hot water feeding port 9 is opened to start feeding of hot water, remaining water within a pipe of downstream side of a hot water storing and temperature keeping container 3 is discharged. After this operation, the hot water of which temperature is kept within the hot water storing and temperature keeping container 3 is discharged. Hot water of predetermined temperature or temperature near the predetermined temperature can be used within a short period of time. Remaining water in a pipe of upstream side may flow into a hot water storing and temperature keeping container 3 until a burner 7 starts ignition to heat a heat exchanger 1 and a predetermined hot water temperature can be attained in the heat exchanger 1. However, since the remaining water is mixed hot water in the hot water storing and high temperature keeping container 3, the remained water is not discharged as it is, resulting in that a temperature of the fed-out hot water from the hot water discharging port 9 is slightly decreased and then the hot water of which temperature is approximately a predetermined temperature is continuously fed. As described above, the hot water feeding port 9 is opened and the water feeding is carried out, resulting in that it is possible to use the hot water of which temperature is a desired one or its near temperature within a short period of time.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an instantaneous water heater.

(Prior Art) For example, in a conventional ordinary instantaneous water heater as shown in FIG.
When the water flow switch or flow rate sensor C installed at an appropriate location in the water system detects water flowing at a level higher than a predetermined level, the burner d starts combustion and heats the heat exchanger e, and thus the heat exchanger e is heated. The hot water passes through the water system and reaches the hot water outlet a.
The hot spring water comes from here. Note that symbols f and M are temperature sensors such as thermistors, g is a check valve, and h is a flow Ill regulating valve.

(Problem to be Solved by the Invention) In such a conventional instantaneous water heater, after the water flow is started and a flow of water exceeding a predetermined level is detected, the burner d starts combustion and the heat exchanger e starts heating. Therefore, immediately after the start of water flow, residual water in the water flow system that has not been heated at all is discharged, and then gradually heated hot water is discharged. Therefore, as shown by the dashed line in FIG. 2, it took a relatively long time, t3 hours, for example, 10-odd seconds, from the start of water flow until hot water at the desired operating temperature was obtained.

The present invention aims to solve this problem.

(Means for Solving the Problems) The configuration of the present invention will be explained with reference to FIG. 1 and FIG. 2 corresponding to the embodiment. In the water flow system 2, a hot water storage and insulation container 3 is provided downstream of the heat exchanger 1, and a pump 4 is provided downstream of the hot water storage and insulation container 3 and upstream of the heat exchanger 1. A reflux system 5 is constructed, and valves 6 are provided at appropriate positions in the reflux system 5.

In the above configuration, the hot water storage and heat insulating container 3 is insulated by surrounding it with a heat insulating material to improve heat retention.

Further, in the above configuration, the valve 6 may be a check valve or any other appropriate valve.

Furthermore, in the above configuration, the flow rate sensor 8 that controls the heating burner 7 of the heat exchanger 1 is located at an appropriate position between the junction position j with the reflux system 5 and the branch position S in the water flow system 2. In addition to being configured in, it can also be configured in other locations depending on the case.

In addition, in the above configuration, when hot water is not being discharged from the hot water outlet 9, the pump 4 and burner 7 are controlled by monitoring the hot water temperature in the hot water storage and heat insulating container 3, or the pump 4 is operated at predetermined intervals. However, by detecting the temperature of the circulating hot water in this operating state and controlling the burner 7, the temperature of the hot water in the hot water storage heat insulating container 3 can be raised to a predetermined temperature.

(Actions and Examples) Next, the operation of the present invention will be explained with reference to illustrated embodiments.

First, if hot water is being drawn from the hot water outlet 9, the pump 4
operation has stopped.

Therefore, water introduced from the water supply port 10 connected to the water supply etc. passes through the water flow system 2, passes through the check valve 11, and then passes through the reflux system 5.
However, due to the presence of the check valve 6, the water does not flow into the reflux system 5 and flows only through the water flow system 2. The water that has thus reached the heat exchanger 1 via the flow rate adjustment valve 12 and the flow rate sensor 8 is heated by the burner 7 to become hot water, which is then discharged from the hot water outlet 9 via the hot water storage container 3. As described above, since the operation of the pump 4 is stopped, hot water does not flow into the reflux system 5 from the branch position S. When hot water is being tapped from the hot water outlet 9 in this manner, water flows through the water passage system 2 in the same way as before, and therefore the control of the burner 7 during hot water tapping can be performed in the same way as before. . For example, water system 2
In this process, fuel is supplied to the burner 7 based on temperature sensors 13 and 14 such as thermistors provided on the upstream and downstream sides of the heat exchanger l, a flow rate sensor 8, a hot water temperature setting device (not shown), etc. Hot water at a desired set temperature can be obtained by adjusting the water supply using feedforward control or feedback control.

Next, when the hot water outlet 9 is closed and hot water is not being tapped, the pump 4 is operated as necessary, and the water in the water flow system 2 enters the reflux system 5 from the branch position S, and the water in the water flow system 2 enters the reflux system 5 from the branch position S. The water passes through the stop valve 6 and reaches a joining position j with the water system 2, and from there it flows through the water system 2 and returns to the branch position S, where it circulates. By burning the burner 7 at the same time as the circulation, it is possible to raise the temperature of the water in the circulation system, and thus the hot water heated to a predetermined temperature can be stored in the hot water storage heat insulating container 3.

In this state, when the hot water outlet 9 is opened to start tapping, the residual water in the piping on the downstream side of the hot water storage and heat insulating container 3 is first discharged from the hot water outlet 9, and then the water is kept warm in the hot water storage and heat insulating container 3. The hot water is discharged. Inside the hot water storage thermal container 3,
At the same time as the hot water is discharged, residual water in the upstream piping flows in and mixes with the hot water inside. On the other hand, when the flow rate sensor 8 detects water flowing through the water passage system 2 due to the start of hot water dispensing, the burner 7 starts combustion and heating of the heat exchanger 1 starts. The control of the burner 7 at the start of tapping the hot water can also be performed in the same manner as in the prior art.

As described above, in the present invention, when the hot water outlet 9 is opened to start tapping, the residual water in the piping on the downstream side of the hot water storage and heat insulating container 3 is first discharged, but after that, the water is kept warm in the hot water storage and heat insulating container 3. Since the hot water that has been stored is discharged, hot water at or close to the predetermined temperature can be used in a short period of time. The burner 7 starts combustion and heats the heat exchanger 1, and until a predetermined hot water temperature is obtained in the heat exchanger 1, the inside of the hot water storage heat insulating container 3 is However, this residual water mixes with the hot water in the hot water storage and heat insulating container 3, so it is not discharged as it is, and therefore, although the temperature of the hot water coming out from the hot water outlet 9 decreases slightly, it remains at a temperature close to the predetermined temperature. Hot water continues to flow.

As described above, the present invention makes it possible to use hot water at a desired temperature or a temperature close to it within a short time t after opening the tap 9 and starting water flow as shown in FIG.

The operation control of the pump 4 and the fuel control of the burner 7 during operation of the pump 4 described above can be performed, for example, by the following method. The first method is to monitor the temperature of the hot water in the hot water storage container 3, and when the local temperature drops below a predetermined temperature, the pump 4 is operated and the burner 7 is controlled to burn. This is a method of raising the temperature to a predetermined temperature. In this method, the hot water temperature in the hot water storage and heat insulating container 3 can be monitored by installing a temperature sensor (not shown) in the hot water storage and heat insulating container 3 to directly monitor the hot water temperature. 3 and the heat exchanger 1 can also be used for indirect monitoring. Next, the second method is to operate the pump 4 at predetermined time intervals, detect the temperature of the circulating water under such operating conditions, and control the combustion of the burner 7 when the temperature is below the predetermined temperature. In this method, the temperature of the circulating hot water and the temperature of the hot water in the hot water storage heat insulating container 3 are raised to a predetermined temperature.

In this method, the temperature of the hot water can be detected by temperature sensors 14, 13, etc. installed at appropriate locations in the circulation path.

In the above explanation, the valve 6 provided in the reflux system 5 is a check valve, but it may also be configured as a solenoid valve or a three-way valve provided at a branch position between the reflux system 5 and the water flow system 2. You can also do that. Note that in the case of a check valve, unlike other valves, it does not require operation such as current application, so the overall configuration and control are simplified.

In the above description, the flow rate sensor 8 that controls the heating burner 7 of the heat exchanger 1 is located between the junction position j with the reflux system 5 and the branch position S in the water flow system 2. In this configuration, the flow rate sensor 8 can also be used to control the burner 7 during the circulation.

The flow M regulating valve 12 in the embodiment is used to reduce the flow rate of hot water to give priority to the set temperature when the hot water load exceeds the capacity of the burner 7.

(Effects of the Invention) As described above, the present invention provides, in a water flow system passing through a heat exchanger of a water heater, a hot water storage and heat insulating container on the downstream side of the heat exchanger, and a hot water storage and heat insulating container on the downstream side of the hot water storage and heat insulating container. A reflux system is configured with a pump provided on the upstream side of the heat exchanger, and when hot water is not being tapped, a burner for heating the heat exchanger is combusted while circulating hot water through the reflux system and the water flow system. Since the hot water in the hot water storage thermal container is heated to a predetermined temperature and stored, hot water at or close to the desired temperature can be used within a short time after opening the hot water outlet and starting water flow. There is an effect. Furthermore, the present invention has the effect that an auxiliary heating source such as an electric heater is not required because the temperature of the hot water in the hot water storage heat insulating container is raised by the burner used for raising the temperature during normal hot water dispensing.

[Brief explanation of the drawing]

FIG. 1 is a system explanatory diagram showing an embodiment of the overall configuration of the present invention, FIG. 2 is an explanatory diagram showing the hot water tapping operation of the present invention and the conventional example, and FIG. 3 is a system explanatory diagram of the conventional example. Code 1... Heat exchanger, 2... Water flow system, 3... Hot water storage heat insulating container, 4... Pump, 5... Reflux system, 6...
... Valve, 7... Burner, 8... Flow rate sensor, 9...
- Hot water outlet, 1o... Hot water supply port, 1... Check valve, 2... Flow rate adjustment valve, 13° 4... Temperature sensor, S... Branch position, j... Merging position.

Claims (5)

[Claims] (1) In a water flow system passing through a heat exchanger of a water heater, a hot water storage and heat insulating container is provided downstream of the heat exchanger, and a hot water storage and heat insulating container is provided downstream of the hot water storage and heat insulating container and upstream of the heat exchanger, 1. An instantaneous water heater comprising a reflux system equipped with a pump, and a valve provided at an appropriate position in the reflux system. (2) The instantaneous water heater according to item 1, wherein the valve is a check valve. (3) In the water heater described in paragraph 1, the flow rate sensor that controls the burner for heating the heat exchanger is configured in the water flow system at an appropriate location between the merging position with the reflux system and the branching position. An instant water heater that is characterized by: (4) In the water heater according to item 1, the instantaneous water heater is characterized in that the water temperature in the hot water storage container is raised to a predetermined temperature by controlling the pump and burner by monitoring the water temperature in the hot water storage container. vessel. (5) In the water heater described in paragraph 1, the pump is operated at predetermined time intervals, and the temperature of the circulating water is detected in this operating state and the burner is controlled, whereby the water in the hot water storage container is heated. An instantaneous water heater that is characterized by raising the temperature to a predetermined temperature.