JPH0833238B2 - Hot water boiler - Google Patents

Description

The present invention relates to a hot water boiler.

(Prior art and its problem) For example, as shown in FIG. 2 (a), in the conventional hot water boiler in which the heat exchanger b is provided in the tank a to raise the water temperature by convection, at the start of operation. Although the temperature difference in the tank a is large, the difference gradually disappears as the temperature rises. Therefore, it is theoretically impossible to lower the temperature of the exhaust gas of the gas burner c below the temperature of the hot water used in the tank a. Therefore, the exhaust temperature is, for example, about 200 ℃ ~ 300
However, the upper limit of thermal efficiency is about 90%. In order to improve the thermal efficiency, for example, as shown in FIG. 2 (b), there is a system in which a heat exchanger d for recovering latent heat of exhaust gas is installed separately from the tank a. At the same time, since the feed water heating pipe e by the recovered heat is also required as a separate body, it is difficult to reduce the size.

The present invention aims to solve these problems.

(Means for Solving the Problem) The present invention will be described with reference to FIG. 1 corresponding to an embodiment. According to the present invention, a partition 2 is provided in a lower portion of a boiler tank 1 and an upper portion of the boiler tank 1 is provided. Convection area U and lower convection area L
And the upper convection zone U is connected to one end side and the other end side of the lower convection zone L, and the communication section 3o on one end side is higher than the communication section 3i on the other end side. The convection water of the lower convection zone L is located at the outflow side o, and the communication portion 3i on the other end side is the inflow side i to the lower convection zone L, and is connected to the upper convection zone U and the lower convection zone L. , The first and second heat exchangers 4 and 5, respectively, are provided, and the burner 6 leads to the first heat exchanger 4, and the first heat exchanger 4 causes the outflow side o.
An upper part of the boiler tank 1, which constitutes an exhaust heat exchange path 7 from the second heat exchanger 5 to the outside of the boiler tank 1 via the inflow side i. Further, a tap hole 8 and a water supply port 9 are provided at appropriate positions on the inflow side i.

(Operation) In the above configuration, the high-temperature exhaust gas from the burner 6 passes through the exhaust heat exchange path 7 and firstly flows through the first heat exchanger 4
Then, heat exchange is performed with the water in the tank 1 here. The water heated by such heat exchange rises, high temperature convection is formed in the upper convection region U as shown by the arrow in the figure, and the hot water temperature in the upper convection region U thus rises.

Next, the exhaust gas, which has radiated heat in the first heat exchanger 4 and whose temperature has dropped, continues through the exhaust heat exchange path 7 and passes through the outflow side o of the lower convection region L to the second heat exchange. Reaching vessel 5,
After heat exchange here, the gas is exhausted from the exhaust port 10 to the outside of the tank 1 through the inflow side i. The water in the lower convection zone L heated by the second heat exchanger 5 flows out into the upper convection zone U from the outflow side communication portion 3o as shown by the arrow in the figure, and also in the upper convection zone U. The lower water flows into the lower convection area L from the communication part 3i on the inflow side, and low temperature convection is formed in this way to recover the heat quantity of the exhaust gas.

Then, when hot water is taken out from the hot water outlet 8 at the upper part of the tank 1 and used, cold water corresponding to the amount of the hot water that has flowed out flows into the tank 1 through the water supply port 9. Since the water supply port 9 is provided at a proper position on the inflow side i of the lower convection zone L, the inflowing cold water is supplied into the lower convection zone L, and the temperature inside the lower convection zone L is lowered. Even the exhaust gas whose temperature has dropped due to heat dissipation in the first heat exchanger 4 can be efficiently heat-exchanged in the second heat exchanger 5. In particular, the second heat exchanger 5 is arranged so that the flow direction of the exhaust gas passing through the second heat exchanger 5 opposes the convection direction of the lower convection zone L, that is, the inflow direction of the cold water, so that heat is exchanged. Exhaust gas exhaust port 10
The more it moves in the direction, the more it exchanges heat with lower temperature water, and the heat exchange can be performed very efficiently.

In this way, it becomes possible to lower the temperature of the exhaust gas to below the dew point temperature in the second heat exchanger 5, and recover not only the sensible heat in the exhaust gas but also the latent heat in water, and thus 100%
It is possible to obtain close thermal efficiency.

(Embodiment) In the illustrated embodiment, the water supply port 9 is formed on the outer side of the lower convection area L on the inflow side i of the lower convection area L, but it may be formed on the inner side in some cases. Alternatively, it can be configured at a plurality of locations.

Further, in the illustrated example, the partition 2 forming the lower convection zone L has a middle portion inclined to form an outflow side o on the high side, a communication section 3o is provided on the upper side, and an inflow side on the lower side. Although i is configured and the communication portion 3i is provided under the i, the specific configuration of the partition 2 and the specific configuration of the communication portions 3o and 3i are appropriate.

(Effects of the Invention) As described above, the present invention artificially configures convection zones having different temperature levels in the upper and lower parts of the boiler tank, respectively provides heat exchangers, and sets the exhaust heat exchange path for passing exhaust gas to the temperature Since the heat exchanger in the upper convection zone with a high level is configured to reach the heat exchanger in the lower convection zone with a low temperature level, it is possible to recover not only sensible heat but also latent heat in the exhaust gas. In particular, in the heat exchanger in the lower convection area, the heat efficiency is very high because it is arranged so that the exhaust gas flow direction and the cold water flow direction are opposite to each other, and it is possible to obtain a heat efficiency close to 100%. is there. Further, according to the present invention, since the convection regions having different temperature levels are integrally formed in the boiler tank, there is an effect that the size can be easily reduced.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing the structure and operation of the present invention, and FIGS. 2 (a) and 2 (b) are schematic explanatory views of a conventional example. Reference numeral 1 ... Boiler tank, 2 ... Partition, 3o, 3i ... Communication section, 4,5 ... First and second heat exchangers, 6 ... Burner, 7 ...
… Exhaust gas heat exchange path, 8 …… Outlet, 9 …… Water inlet, 10…
… Exhaust port, 11 …… Thermometer, U… Upper convection zone, L… Lower convection zone, o …… Outflow side, i …… Inflow side.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-57-58037 (JP, A) Actually developed 56-50946 (JP, U)

Claims (1)

[Claims] 1. A partition is provided in the lower part of the boiler tank to divide the inside of the boiler tank into an upper convection region and a lower convection region, and one end side and the other end side of the lower convection region are divided into upper convection regions. A communication part is formed, and the communication part on one end side is arranged at a position higher than the communication part on the other end side so as to be the outflow side of the convective water in the lower convection area, and the communication part on the other end side is connected to the lower convection area. The first and second heat exchangers are provided in the upper convection region and the lower convection region, respectively, from the burner to the first heat exchanger, and from the first heat exchanger. An exhaust heat exchange path is formed from the second heat exchanger to the second heat exchanger and to the outside of the boiler tank from the second heat exchanger to the outside of the boiler tank. And a hot water boiler, wherein a water supply port is provided at an appropriate position on the inflow side.