WO1980002737A1

WO1980002737A1 - Natural circulation-type hot water storage heater

Info

Publication number: WO1980002737A1
Application number: PCT/JP1980/000113
Authority: WO
Inventors: T Yoshida
Original assignee: Mitsubishi Electric Corp; T Yoshida
Priority date: 1979-06-01
Filing date: 1980-05-28
Publication date: 1980-12-11
Also published as: DE3047559T1; GB2070210B; EP0034186B1; JPS55160253A; AU5985780A; EP0034186A1; EP0034186A4; AU519498B2; BE883550A; GB2070210A; DE3047559C2

Abstract

A natural circulation-type hot water storage heater for storing hot water obtained from a water storage tank (as water or hot water) at the bottom through a first circulation pipe, a heat exchanger and a second circulation pipe into a tank. A thermovalve is mounted within the second circulation pipe on the downstream side of the heat exchanger to vary its opening area in response to the hot water temperature to thereby substantially maintain constant the temperature of the hot water from the heat exchanger. As a result, the temperature distribution at the time the water is boiling in the water storage tank is rendered substantially constant instantaneously so as to increase the effective hot water storage amount. In addition, the hot water temperature is held constant without fluctuation regardless of the repetitive ON and OFF operation of a burner, and will not fluctuate even if the burner is turned ON when hot water is supplied. Instead, the time during which the hot water is continuously supplied at constant temperature is prolonged to provide an effective hot water storage amount which is greater than the inside volume of the water storage tank.

Description

Specification '

Title of invention

Natural circulation type hot water storage system ''

TECHNICAL FIELD-This invention is based on a natural circulation hot water supply with a circulation pipe.

It is about a hot water heater.

Background art

Fig. 1 shows the structure of a conventional natural circulation hot water storage type hot water supply system.

It has become.

A conventional natural circulation hot-water storage type hot water supply system is explained with reference to Fig. 1.

The water in the hot water storage tank with the water supply port (1) and the hot water supply port) is supplied to the second circulation pipe ( ⁴ ) connected to the bottom of the tank.

After passing through the heat exchanger ( ⁵ ), the heat from the combustor ( ⁶ ) is

Hot water and the hot water is stored in a second circulation pipe).

(3) Supply to the upper part.

In this case, the average of the water passing through the first circulation pipe ( ⁴ )

The density of the hot water passing through the second circulation pipe ( ⁷ ).

When the height from the center of the heat exchanger ( ⁵ ) to the boundary between the hot water and the water in the hot water tank is 2, the natural circulation force F

Is

5, the first circulation pipe (4), the heat exchanger (5) and the second circulation pipe

Water or hot water flow rate through the I Bed ⁽⁷⁾ or al ing circulation path A

ω is

O PI

——— — ω QC F ⁿ ( _n ≥ 1) (2)

It is known that the following relationship holds.

Also, heat exchanger) to your stomach combustor ⁽⁶⁾ whether these heat-receiving amount by the water get in heat, tee ratio heat of water a C _P, enter the mouth and exit of the heat exchanger ⁽⁵⁾ If the temperature of the water or hot water at is Tin, Out,

(= Q, / Cp (T out one Tin) (3)

And na! ), Equations (2) and (3) above]?

1

C F (4)

(Tout-Tin)

The following relationship holds, and the smaller the natural circulation force F, the larger the temperature difference ( _T0ut —Tin).

In other words, as shown in Fig. 1, a dashed line appears inside the hot water tank ( ³ ).

湯 decreases to I! When hot water is stored up to the portion indicated by, and (（

-2) increases slightly, but the decrease rate of H is larger.

The natural circulation force F in Eq. (1) decreases and the temperature difference (T _0ut- Tin) before and after the heat exchanger becomes large j? This means that the temperature difference (Tout-Tin) increases as the amount of hot water stored in the upper part of the tank increases. Based on this principle, the boiling point in the tank of a conventional natural circulation type hot-water storage water heater! ? As shown in Fig. 2, the temperature distribution had a temperature gradient at the bottom of the tank where low-temperature hot water was present at the beginning of hot water storage, and where higher temperatures were present at the top of the tank. Therefore, the amount of high-temperature hot water that can be used, that is, the effective hot water storage, is the actual tank internal volume! ) Also had the disadvantage of being small. EAC

OMPI

WIFO When hot water is supplied, use hot water.]? Circulating power? In other words, since the amount of outflow from the second circulation pipe fluctuates, the boundary between hot water and water fluctuates, and the combustion of the combustor ( ⁶ ) turns ON-OFF.

Return, but when the combustion is 0 N, the amount of hot water stored in the hot-water tank decreases, so the natural circulation force F increases! ), 2nd circulation type]) The temperature of the hot water flowing out is low and the temperature of hot water supply is also low. Conversely, when the combustion is turned off, the amount of hot water stored in the tank is large, and the circulation force F is small and high-temperature hot water is supplied. Therefore, as shown in Fig. 5, the temperature of the hot water fluctuated greatly during hot water supply, making it unsuitable for use in, for example, a car.

Disclosure of invention

The purpose of the present invention is to eliminate such drawbacks of the conventional natural circulation type hot water supply type water heater, and it is desirable to provide the circulation pipe at the outlet side of the heat exchanger. Install a thermo-valve that operates so that the opening area decreases as the temperature of the hot water increases and the opening area decreases as the temperature decreases. 3) In the tank To increase the effective hot water storage capacity by making the temperature distribution the same for the entire tank and to increase the effective hot water storage capacity, and to provide a natural circulation type hot water supply water heater that does not fluctuate when hot water is supplied. is there .

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 to Fig. 3 show a conventional natural circulation type hot water storage type hot water supply system. Fig. 1 is a schematic front view of the entire vertical section, and Fig. 2 is a view of the hot water supply system when boiling. Temperature distribution in tank, No.

Figure 3 shows the change in hot water temperature when using the hot water heater! ? , One O PI _

, WIPO. Fig. 4 to Fig. 8 show an embodiment of the natural circulation hot water storage type water heater according to the present invention, Fig. 4 is a schematic front view of the entire longitudinal section, and Fig. 5 is a thermometer. Fig. 6 is a vertical cross-sectional front view showing the closed state of the valve. Fig. 6 is a vertical cross-sectional front view showing the open state of the thermovalve. Fig. 7 is the tank at the time of boiling up in the water heater. Temperature distribution diagram, Fig. 8 is a diagram of change of hot water temperature when using the hot water heater U, Fig. 9 is a diagram of change of hot water temperature when using conventional and hot water heater of the present invention .

Best mode for carrying out the invention

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

In Fig. 4, (1) is a water inlet, (a) is a hot water inlet, ( ³ ) is a hot water storage tank, is a first circulation pipe, ( ⁵ ) is a heat exchanger, and) is a combustor. ( ⁷ ) is the second circulation pipe. The features of the present invention are as follows: When the temperature of the hot water rises in the second circulation pipe (downstream of the heat exchanger (5) interposed in the circulation path A), the opening area increases. A thermovalve ( ⁸ ) that operates so that the opening area becomes smaller when the temperature becomes lower is provided.

As shown in Fig. 5, the thermo-valve (S) is a conical orifice fixed near the outlet of the heat exchanger inside the second circulation pipe ( ⁷ ). The pin-shaped fixing plate W and the spring fixing plate 1) are fixed to the plate ( ⁹ ), and the disc-shaped movable plate fixed to the thermosensitive part ^ with thermo-wax is fixed. The movable plate & 3 and the sub-ring fixing plate &!) Are positioned close to the orifice plate ( ⁹ ).

O PI WIPO The spring (14) is arranged between the two, and the end of a pin (15) that extends and contracts from the upper end of the temperature sensing part 3 by itself comes into contact with the bin fixing plate ω. You.

The thermomix enclosed in the temperature sensing part (12) changes into a liquid phase or a solid phase in accordance with the temperature of the hot water, and expands or contracts. 5 pin (expands and contracts 13. Therefore, when the temperature of the hot water is low and the wax shrinks, the spring 4 Depends on the extension force of)!) The temperature-sensing part & ² ) is pushed upward through the movable plate (13) against the spring fixing plate (ID), resulting in a conical orifice. Disk ( ⁹ ) and disk-shaped movable plate

& ³ ) The area of the hot water distribution section between them is small.], And the circulation flow rate ω is small. Conversely, when the temperature of the hot water rises, the wax expands, and the movable plate ³ ) is pushed downward against the spring (14) in the opposite direction from the above, and the movable plate ³ ) is pushed downward. As shown in FIG. 5, the area of the circulation section between the orifice plate ( ⁹ ) and the movable plate & ³ ) is large.] 3, and the circulation flow rate ω increases.

Then take a thermo valve like this! The operation of the embodiment of the water heater according to the present invention will be described.

In Fig. 4 or Fig. 1, first, in the case of hot water storage, the hot water discharged from the heat exchanger (S) after the combustor (0) has passed through the second circulation pipe ( ⁷⁾ After), the hot water tank starts to accumulate at the top of). In addition, when a small amount of hot water is stored in the upper part of the tank, the circulation temperature is conventionally large and the circulation flow rate ω is large, so that the outlet temperature of the heat exchanger is low. Is the outlet temperature If the temperature is to be lowered, the temperature (12) of the thermo-valve (S) senses this, and operates to reduce the flow passage area and decrease the flow rate of hot water. In addition, when a large amount of hot water is stored in the hot water storage tank, the circulation force i is small, the flow rate is small, and the outlet temperature is high in the past. In this invention, if the outlet temperature becomes high, the thermovalve ( ⁸ ) senses and operates so as to increase the flow rate of hot water. ) independently of the circulation flow rate to the hot water storage amount in the ing substantially constant. by the action of the Yo I Do support over model alve ^(8)] ?, heat exchanger

The hot water temperature Tout at the outlet of ( ⁵ ) is controlled to be substantially constant.

Therefore, as shown in Fig. 7, the temperature distribution in the hot water tank of the hot water heater at the time of rising D is as shown in Fig. 7.

The temperature of the hot water storage becomes substantially constant over the entire period, so that the hot water can be stored as effectively as possible with respect to the internal volume of the hot water storage tank.

If the amount of hot water supplied during hot water supply becomes smaller than the circulating flow rate ω] 3, the combustor (6) is repeatedly turned on and off, but the hot water with a substantially constant temperature change from the second circulation pipe ( ⁷ ) As shown in Fig. 8, continuous hot water can be supplied at a stable hot water temperature regardless of whether combustion is ON or OFF.

Also, in your in case hot water supply amount has not come large good circulation flow rate ω, can the fourth diagram of the broken line B ₂ or combustor is water supply ⁽⁶⁾ is Tsu name to the combustion 0 N, the hot water supply amount W, from the dashed line B 2 exit position of the second circulation pi Bed) (V. the amount of hot water storage at the broken line B ₃₎ or Figure 9 shows the change in hot water supply temperature when the natural circulation flow rate is assumed. Thus, in the conventional natural circulation type hot water supply type hot water supply system, the temperature of the hot water fluctuated simultaneously with the start of combustion (point c) as shown by the broken line X in the figure. In the water heater of the present invention, the temperature out of the hot water flowing through the second circulation pipe is constant due to natural circulation, so that the hot water supply amount is substantially (W—ω). After the start of combustion (point C) as shown by Y, hot water of a constant temperature

Yo / one Ύ ₀ ZW (5)

The hot water can be supplied for a long time, and the effective hot water storage capacity exceeds the internal capacity of the hot water storage tank.

Claims

The scope of the claims _

1. A circulation pipe having a heat exchanger in the middle, one end connected to the bottom of the hot water storage tank and the other end located at the top of the hot water storage tank, In a natural circulation hot water storage system that stores heated water from the top of the hot water storage tank, the temperature of the hot water is not high downstream of the heat exchanger of the circulation pipe. The opening area increases when the temperature decreases.)) A thermo-palm that reduces the opening area when the temperature of the hot water decreases decreases the temperature of the hot water flowing out of the circulation pipe. A naturally circulating hot water supply type hot water supply system characterized by the fact that it is configured to be hot water.

2. It is characterized that the heat exchanger is heated by the combustor.

The natural circulation type hot water supply machine according to claim 1.

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