JP2002357362A - Water heater - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the reliability of flow rate measurement by eliminating movable parts. SOLUTION: This water heater comprises ultrasonic sensors 10, 11,
Ultrasonic flow rate measuring means 12, 15, 1 for measuring the flow rate based on transmission / reception signals from 13, 14, 16, 17, 19
8 is provided. According to this configuration, since there is no movable part in the flow path, a trouble such as clogging of dust does not occur, and the reliability of the flow rate measurement is improved. Therefore, a failure as a water heater can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water heater using gas, oil or electricity as a heat source, and more particularly to a water heater having an ultrasonic flow rate measuring means.

[0002]

2. Description of the Related Art Conventionally, this type of water heater is disclosed in
No. 4158 was known. Hereinafter, the configuration will be described with reference to FIG.

[0005] As shown in FIG. 5, the apparatus includes an impeller 2 installed in a flow path 1, a pulse generator 3, a signal processor 4, and a time width controller 5. Here, 6 is a data memory, 7 is a data selector, and 8 is a control valve.

In the above configuration, when a fluid flows in the flow path 1, the impeller 2 rotates. The pulse generator 3 converts the rotation of the impeller 2 into a pulse signal. Then, the fluid flow rate can be obtained by the measurement processing unit 4 from the pulse signal.

[0005]

However, in the above-mentioned conventional configuration, the impeller 2 is located in the flow path 1, and an abnormality occurs in the rotation of the impeller 2 due to dust or the like, which causes a problem in the flow rate measurement. was there.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problem, and comprises an ultrasonic flow rate detecting means for detecting a flow rate from a propagation time of a sound wave transmitted and received by transmitting an ultrasonic wave in the flow path. Has no movable parts, and aims to perform highly reliable measurement without causing a problem of clogging with dust and the like.

[0007]

In order to solve the above-mentioned conventional problems, an ultrasonic transmitting / receiving means provided in a flow path, an ultrasonic propagation information measuring means, and a flow rate are measured from the propagation information of the propagation information measuring means. And a configuration provided with an ultrasonic flow rate measuring means.

[0008] By adopting the configuration using the propagation information of the ultrasonic wave, there is no movable portion in the flow path, and there is no problem that clogging of dust or the like occurs. be able to.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to a first aspect of the present invention is directed to an ultrasonic transmission / reception means provided in a flow path, an ultrasonic wave propagation information measuring means, and an ultrasonic wave measuring apparatus for measuring a flow rate from propagation information of the propagation information measuring means. By equipping the water heater with an ultrasonic flow rate measuring means, there is no movable part in the flow path, and there is no problem of clogging with dirt, etc. it can.

[0010] The second aspect of the present invention is to provide an ultrasonic flowmeter as a water amount measuring means, so that there is no movable portion in the flow path, and there is no problem that clogging of dust or the like occurs, and highly reliable measurement can be performed. It is possible to reduce the abnormality of the water heater.

According to the third aspect of the present invention, the ultrasonic flowmeter is provided as a fuel flow rate measuring means, and the combustion can be controlled in more detail by measuring the fuel flow rate.

According to the fourth aspect of the invention, the ultrasonic flowmeter is provided as an air flow rate measuring means, and the combustion can be controlled in more detail by measuring the air flow rate.

According to a fifth aspect of the present invention, at least one of the propagation information measuring means of the water flow measuring means, the propagation information measuring means of the fuel flow measuring means, and the propagation information measuring means of the air flow measuring means is shared. By doing so, a water heater can be realized with a simple configuration even if a plurality of ultrasonic flowmeters are used.

According to a sixth aspect of the present invention, the propagation information measuring means includes a propagation time measuring means for measuring the propagation time of the ultrasonic wave as the propagation information, and the time measurement can be performed with high accuracy. Can be improved.

According to a seventh aspect of the present invention, the provision of the temperature measuring means for detecting the temperature from the propagation information of the propagation information measuring means makes it possible to measure the water temperature with higher accuracy and to control the water temperature of the water heater more. High accuracy can be achieved.

[0018] The invention according to claim 8 is provided with fuel discriminating means for discriminating the type of fuel from the propagation information of the propagation information measuring means, so that combustion can be controlled by discriminating the type of fuel and abnormal combustion can be performed. This can prevent the water heater from being abnormal.

According to a ninth aspect of the present invention, at least one of the ultrasonic transmitting / receiving means of the water amount detecting means and the ultrasonic transmitting / receiving means of the temperature measuring means is used, and the flow rate and the temperature are determined from the ultrasonic propagation information. The provision of the flow rate measuring means and the temperature measuring means for detecting the respective components makes it possible to use both the water amount measuring means and the temperature measuring means, thereby simplifying the configuration of the water heater.

According to a tenth aspect of the present invention, at least one of the ultrasonic transmission / reception means of the fuel flow rate detection means and the ultrasonic transmission / reception means of the fuel discrimination means is used, and the flow rate and the fuel quantity are determined based on the ultrasonic propagation information. By providing the flow rate measuring means and the fuel determining means for respectively detecting the types of water, the water amount measuring means and the temperature measuring means can be shared, and the configuration of the water heater can be simplified.

[0019] According to an eleventh aspect of the present invention, the water flow rate measuring means measures the flow rate at predetermined intervals, and the fuel flow rate measuring means, the air flow rate measuring means, the temperature measuring means, and the fuel determining means determine that the water flow rate measuring means measures the flow rate. By providing a water heater control unit that operates after the detection and stops after the flow amount is no longer detected, the other measurement units are stopped, and only the water amount measurement unit always measures the flow amount at a predetermined interval. Therefore, measurement can be performed at short time intervals, it is possible to immediately detect that water has been used, and it is possible to measure low power consumption by stopping other measuring means.

According to a twelfth aspect of the present invention, the water amount measuring means and the temperature measuring means measure at predetermined intervals, and the fuel flow rate measuring means, the air flow rate measuring means and the fuel discriminating means determine that the water amount measuring means detects the flow rate. The water heater control means for controlling the operation after the water supply can be performed, the water amount measurement means and the temperature measurement means can always be measured at predetermined intervals, and therefore, it can be immediately detected that water has been used. In addition, since the water temperature can be measured even when the water is not used, freezing or the like can be detected in advance.

According to the thirteenth aspect of the present invention, the transmission information measuring means can also be used by providing the switching means for sequentially switching and using the ultrasonic transmitting and receiving means.

According to a fourteenth aspect of the present invention, there is provided an operation judging means for judging whether or not the ultrasonic transmitting / receiving means is operating normally. can do.

According to the fifteenth aspect of the present invention, by disposing the ultrasonic transmitting / receiving means outside the wall surface of the flow path, there is no movable portion in the flow path, so that dust and the like are not clogged and the occurrence of problems is reduced. This can improve the stability of the operation of the water heater.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) Embodiment 1 of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2,
Ultrasonic sensors 10 and 11 as ultrasonic transmitting and receiving means for measuring the amount of water in the gas water heater 9 and a water amount measuring means 12 for measuring the flow rate of water from the propagation time of the ultrasonic waves are provided. And ultrasonic sensors 13 and 14 as ultrasonic transmitting and receiving means for measuring the flow rate of gas as fuel,
The fuel flow rate measuring means 15 for measuring the flow rate of gas as fuel from the propagation time of the ultrasonic wave is provided.

Further, an ultrasonic sensor 1 as an ultrasonic transmitting / receiving means for measuring a flow rate of air supplied for combustion.
6, 17 and an air flow rate measuring means 18 for measuring the flow rate of the air from the propagation time of the ultrasonic waves. The ultrasonic sensor 19 as an ultrasonic transmission / reception unit for detecting a tapping temperature and a temperature measurement unit 20 for detecting a temperature from the propagation time of the ultrasonic wave are provided. A switching unit 21 for switching and using each of 11, 13, 14, 16, 17, and 19, a transmitting / receiving unit 22 for transmitting / receiving an ultrasonic wave, and a transmission time measuring unit 23 for the ultrasonic wave. .

Further, a fuel discriminating means 24 for discriminating the kind of fuel from the propagation times of the ultrasonic sensors 13 and 14 for measuring the gas flow rate is provided. Here, 25 is a water amount control valve as a passage opening / closing means, 26 is a stepping motor for driving the water amount control valve, 27 is a gas control means for adjusting a gas flow rate, 28 is a gas combustion burner, and 29 is an air supply. 30 is a water heater control means, 31 is a heat exchanger, 32 is a water pipe, 33 is a gas pipe, 34 is a water tap, 35 is an operation discriminating means, and 36 is a control device including the above means.

According to the above configuration, the flow rate of water can be measured by the configuration as shown in FIG. That is,
The propagation time T1 from when the ultrasonic wave is transmitted from the upstream ultrasonic sensor to when it is received by the downstream ultrasonic sensor 11, and when the ultrasonic wave is transmitted from the downstream ultrasonic sensor and received by the upstream ultrasonic sensor 10 Propagation time T2 is measured by the propagation time measuring means 23. These propagation times T1,
From T2, the flow rate Q can be measured by the following equation.

Q = {S * D / (sin θ * cos θ)} * (1 / T1-1 / T2) (1) where S is the cross-sectional area of the flow path, D is the pipe diameter of the flow path, θ Is the traveling angle of the ultrasonic wave propagating between the ultrasonic transmitting and receiving elements. Although the propagation distance needs to consider the thickness of the flow path wall, it is omitted here because it is extremely short with respect to the underwater propagation distance.

Further, the temperature of water can be measured from these transmission / reception information by using the following calculation formula. First, the propagation speed Cw of the ultrasonic wave in water is approximated by a linear expression in a predetermined temperature range. For example, Cw = a * T +
C0. Then, the water temperature Tin can be obtained by substituting the propagation speed Cw 'calculated from the reciprocal sum of the propagation times. That is, Cw ′ = (D / sin θ) * (1 / T1 + 1 / T2) (2) Tin = (Cw′−C0) / a (3) In this way, it is obtained from the transmission and reception of a pair of ultrasonic sensors. From the obtained propagation time information, the water flow rate and the water temperature can be measured. By using both the ultrasonic sensor and the propagation time measuring means, the flow rate and the temperature can be measured with high accuracy with a simple configuration. Furthermore, by installing an ultrasonic sensor outside the tube as shown in FIG. 3, it is possible to keep the flow path free from obstacles, and to greatly improve the reliability and durability against dust clogging and the like. Can be.

Further, the tapping temperature Tout can be measured regardless of the flow rate by installing the ultrasonic sensor 19 perpendicular to the pipe line as shown in FIG. In this configuration, the measured temperature Tout is obtained as in the following equation. First, the propagation speed Cw 'in water is obtained from the propagation time T3 of the ultrasonic wave.

Cw '= 2D / T3 (4) Then, similarly to the above, Tout = (Cw'-C0) / a (5) is used. Also at this time, since the propagation time measuring means can be shared, the water amount measuring means and the temperature measuring means can be realized with a simple configuration.

Similarly, the flow rate of the fuel gas can be measured from the propagation time measured using the ultrasonic sensors 13 and 14 using the equation (1). Then, the type of gas can be determined by measuring the propagation velocity Cg ′ in the gas by the following equation as in the case of obtaining the water temperature.

Cg ′ = (D / sin θ) * (1 / T1 + 1 / T2) (6) Here, the propagation speed of the city gas differs from that of the LP gas by about twice, and the propagation time also differs by about twice. Measured.
Therefore, by estimating the gas type from the measured propagation velocity data and comparing it with the gas type data of the gas water heater set in advance in the storage device, it is possible to determine whether the correct gas type is being used. Can be determined. If used with different gas types,
The gas can be shut off by the immediate gas control means, and the safety function can be greatly improved.

Further, the flow rate of air indispensable for combustion can be easily measured by installing the ultrasonic sensors 16 and 17. The principle of measuring the flow rate is the same as in the above embodiment, and will not be described. By measuring the flow rates of gas and air with high accuracy, fine control of combustion can be performed, and reduction of NOx and generation of CO can be largely suppressed. Obviously, if a NOx sensor or a Co sensor is attached, the combustion can be controlled by feedback control.

Then, a predetermined amount of combustion is determined from the set tap water temperature, the actual inlet water temperature Tin and the tap water temperature Tout to control the required gas flow rate and the required air flow rate, and the stepping motor controls the flow rate of the water. The water temperature can be set to the set temperature with higher accuracy and in a shorter time by adjusting the water amount control valve to be controlled. The flow rate of each of water, gas, and air can be measured with high accuracy and instantaneously, and more precise tapping characteristics can be obtained by precisely controlling the flow rate of water.

The water flow rate measuring means measures the flow rate at predetermined intervals, and the fuel flow rate measuring means, the air flow rate measuring means, the temperature measuring means, and the fuel discriminating means operate after the water flow rate measuring means detects the flow rate. Since the water heater control means for controlling to stop after detecting no water is provided, the other measuring means can be stopped and only the water amount measuring means can always measure the flow rate at a predetermined interval. The measurement can be performed at time intervals, the use of water can be immediately detected, and the power consumption can be reduced by stopping other measuring means.

Further, since the temperature measuring means also performs the measurement at a predetermined interval, the water amount measurement and the temperature measurement can always be measured at the predetermined interval regardless of the use of the water. In addition to being able to detect, the water temperature can be measured even when the water is not used.
Therefore, freezing in winter or the like can be detected in advance. If freezing can be detected in advance, freezing can be prevented by heating using a heater or the like.

Further, by providing switching means for sequentially switching and using the ultrasonic sensors, the transmission information measuring means can also be used, and the operation determining means can determine the normal operation of the ultrasonic sensor. Thus, the failure of the ultrasonic sensor can be determined.

As described above, signal processing means such as transmission / reception and measurement of propagation time can be shared by merely installing an ultrasonic sensor. Therefore, a high-performance water heater having a simple structure of tapping characteristics and combustion characteristics can be used. Can be realized. In addition, by transmitting and receiving ultrasonic waves from outside the flow path, a failure such as clogging of dust can be reduced and a highly reliable water heater can be obtained.

Although the gas water heater has been described, it is apparent that the same effect can be obtained also in the oil water heater by replacing the gas fuel flow rate measurement with the oil fuel flow rate measuring means. Also, it can be considered that the effect of the water flow rate measuring means can be sufficiently obtained also in an electric water heater or a heat pump water heater which is a water heater using electricity as a heat source. In addition, although the description has been given of the case where the water flow path, the gas flow path, and the air flow path are all used, the features can be exhibited even if they are individually installed in each of them.

[0042]

According to the water heater of the present invention as described above, the following effects can be obtained.

The present invention has an ultrasonic flow rate measuring means for measuring a flow rate by transmitting and receiving an ultrasonic wave, so that there is no movable portion in the flow path, and there is no problem that dust or the like is clogged and reliability is improved. High measurement can be performed. Then, the flow rate measurement, the temperature measurement, and the fuel determination can be performed only by changing the processing means, and a high-performance water heater with a simple configuration can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a water heater according to a first embodiment of the present invention.

FIG. 2 is a block diagram of the water heater.

FIG. 3 is a configuration diagram of a flow rate measuring unit of the water heater.

FIG. 4 is a configuration diagram of a temperature measuring unit of the water heater.

FIG. 5 is a block diagram of a conventional water heater.

[Explanation of symbols]

10, 11, 13, 14, 16, 17, 19 Ultrasonic sensor (ultrasonic transmission / reception means) 12 Water flow rate measurement means (flow rate measurement means) 15 Fuel flow rate measurement means (flow rate measurement means) 18 Air flow rate measurement means (flow rate measurement means) 20 temperature measuring means 23 propagation time measuring means (propagation information measuring means) 24 fuel discriminating means 25 water amount control valve (flow path opening / closing means) 30 water heater control means 35 operation discriminating means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeru Shirai 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. Term (reference) 2F030 CA03 CE26 CE27 2F035 AA06 DA19 2F056 YF00 3L034 CA03

Claims (15)

[Claims] 1. A water heater comprising: an ultrasonic transmission / reception unit provided in a flow path, an ultrasonic wave propagation information measuring unit, and an ultrasonic flow rate measuring unit for measuring a flow rate from propagation information of the propagation information measuring unit. . 2. The water heater according to claim 1, wherein the flow rate measuring means is a water amount measuring means. 3. The water heater according to claim 1, wherein the flow rate measuring means is a fuel flow rate measuring means. 4. The water heater according to claim 1, wherein the flow rate measuring means is an air flow rate measuring means. 5. The transmission information measuring means of the water amount measuring means, the propagation information measuring means of the fuel flow rate measuring means, and at least one of the propagation information measuring means of the air flow rate measuring means. The water heater according to claim 1. 6. The water heater according to claim 1, wherein the propagation information measuring means is a propagation time measuring means for measuring a propagation time of an ultrasonic wave as propagation information. 7. The water heater according to claim 1, further comprising a temperature measuring means for detecting a temperature from the propagation information of the propagation information measuring means. 8. The water heater according to claim 1, further comprising fuel discriminating means for discriminating the type of fuel from the propagation information of the propagation information measuring means. 9. An ultrasonic transmission / reception means of water amount detection means and at least one of ultrasonic transmission / reception means of temperature measurement means, and a flow rate measurement means for detecting a flow rate and a temperature from propagation information of the ultrasonic wave, respectively. The water heater according to any one of claims 1 to 8, further comprising a temperature measuring unit. 10. An ultrasonic transmission / reception means of fuel flow rate detection means and at least one of ultrasonic transmission / reception means of fuel discrimination means, and a flow rate and fuel type discrimination are detected from ultrasonic propagation information. The water heater according to any one of claims 1 to 9, further comprising a flow rate measuring means and a fuel discriminating means. 11. The water flow rate measuring means measures the flow rate at a predetermined interval, and the fuel flow rate measuring means, the air flow rate measuring means, the temperature measuring means and the fuel determining means operate after the water flow rate measuring means detects the flow rate, A water heater control means for controlling so as to stop after the flow rate is not detected.
The water heater according to any one of claims 10 to 13. 12. The water amount measuring means and the temperature measuring means measure at predetermined intervals, and the fuel flow measuring means, the air flow measuring means and the fuel determining means operate so that the water amount measuring means operates after detecting the flow rate. The water heater according to any one of claims 2 to 10, further comprising a water heater control means for controlling the water heater. 13. The water heater according to claim 1, further comprising switching means for sequentially switching and using the ultrasonic transmission / reception means. 14. An apparatus according to claim 1, further comprising operation determining means for determining whether the ultrasonic transmitting / receiving means is operating normally.
A water heater according to any one of claims 13 to 13. 15. The water heater according to claim 1, wherein an ultrasonic transmitting / receiving means is arranged outside a wall surface of the flow path.