JP3332494B2 - Waste gas heat recovery unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recovering thermal energy from waste gas discharged from work performed by an engine.

[0002]

2. Description of the Related Art Waste gas emitted from an engine-driven air conditioner, that is, exhaust gas discharged from an engine which is a driving force source of an outdoor unit, has a considerably high temperature. , Which is recovered by using a heat exchanger and then released to the atmosphere via a chimney or the like, has been proposed in, for example, Japanese Patent Application Laid-Open No. 60-86355, and has already been put to practical use. .

As is well known, a large amount of water (steam) is generated when a hydrocarbon such as gas or petroleum burns. For this reason, a large amount of water vapor is also contained in the waste gas emitted from the engine, and at the time of the heat recovery by the heat exchanger, a part of the moisture contained in the waste gas is, for example, a cooling water coil. The condensed water is drained through a drain water pipe or the like.

[0004]

However, the drain water condensed from the waste gas is generally acidic at around pH 4, depending on the type of fuel, the place of production, the combustion conditions, etc., and is generally neutralized. Later, the water is drained through drain water piping. In addition, if drainage is performed without neutralization, there is a problem that not only the drain water pipe but also concrete and the like at the place where the apparatus is installed are corroded, and solving this point has been a problem.

[0005]

According to the present invention, as a specific means for solving the above-mentioned problems in the prior art, a waste gas and a cooling fluid from an engine driven by using gas or oil as fuel are transmitted. In a waste gas heat recovery unit that thermally contacts via a heat pipe and transfers heat energy held by the waste gas to a cooling fluid to recover heat,

[0006] A waste gas drain chamber partitioned from the heat recovery chamber through a bottom plate having an opening of the heat recovery chamber accommodating the heat transfer tube and communicating only with the heat recovery chamber is provided below the heat recovery chamber; A waste gas heat recovery unit having a first configuration, wherein the waste gas drain chamber is provided through a waste gas passage for guiding waste gas to the heat recovery chamber;

[0007] A waste gas drain chamber partitioned from the heat recovery chamber via a bottom plate having an opening of the heat recovery chamber accommodating the heat transfer tube and communicating only with the heat recovery chamber is provided below the heat recovery chamber; A waste gas heat recovery unit having a second configuration, wherein a waste gas passage for guiding waste gas to the heat recovery chamber is provided outside the waste gas drain chamber. This is to solve the problems of the prior art.

[0008]

In the case of claim 1, when the temperature of the cooling fluid flowing in the heat transfer tube and the temperature of each part of the waste gas heat recovery device is low, the steam contained in the waste gas comes into contact with the surface of the heat transfer tube. The condensed water becomes drain water and is separated from the heat recovery chamber through a bottom plate having an opening of the heat recovery chamber, communicates only with the heat recovery chamber, and flows into a waste gas drain chamber provided below the heat recovery chamber. However, when the temperature of the cooling fluid flowing through the heat transfer tube and the temperature of each part of the waste gas heat recovery unit rises over time, the water vapor in the waste gas does not condense even when it comes into contact with the heat transfer tube, and the waste gas drains into the waste gas drain chamber. No drain water flows in.

On the other hand, in the waste gas drain chamber into which the drain water has flowed, the heating action by the waste gas flowing through the waste gas passage provided to penetrate the waste gas passage and the heat recovery chamber always operates. At the beginning of the heat recovery, the drain water that has flowed into and stored therein evaporates. This allows
Piping or the like for draining drain water becomes unnecessary.

In the case of claim 2, the drain water flowing into the waste gas drain chamber flows through the waste gas passage provided along the outside of the waste gas drain chamber in the same manner as in the above-mentioned claim 1, and flows into the heat recovery chamber. It is heated by the heat of the incoming waste gas and evaporates. Therefore, also in this case, piping for discharging drain water is not required.

[0011]

【Example】

Embodiment 1 Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIG.

In FIG. 1, reference numeral 1 denotes a heat recovery chamber.
A number of heat transfer tubes 2 formed of a metal such as stainless steel are provided in a horizontal direction.

Cooling water is supplied to each of the heat transfer tubes 2 through a header 4 from a cooling water inlet 3 provided to open in the horizontal direction, and a cooling water outlet provided similarly to the cooling water inlet 3. From 6, the water can be drained through the header 5.

Reference numeral 7 denotes a waste gas drain chamber provided below the bottom plate 8 of the heat recovery chamber 1. The waste gas drain chamber 7 is connected to the heat recovery chamber 1 through an opening 9 provided at a position near the header 4 of the bottom plate 8. Communicating. The bottom surface of the waste gas drain chamber 7 is not horizontal, but is inclined so that the side near the header 5 is lower.

Reference numeral 10 denotes a waste gas inlet to the heat recovery chamber 1 which is provided at a position close to the header 5 of the bottom plate 8, and the waste gas inlet 10 is connected to a combustion chamber (not shown) of an engine. A waste gas introduction passage 11 for guiding a high-temperature waste gas discharged from the apparatus is connected to the pipe so as to penetrate the inside of the waste gas drain chamber 7.

Reference numeral 12 denotes a waste gas outlet provided at a position near the header 4 of the top plate 13 of the heat recovery chamber 1, and a waste gas exhaust passage 14 is connected to the waste gas outlet 12 by piping. I have.

Reference numeral 15 denotes a baffle which is alternately disposed inside the heat recovery chamber 1 from above and below. The baffle 15 allows the waste gas flowing into the heat recovery chamber 1 from the waste gas inlet 10 to meander, so that heat exchange between the waste gas and the cooling water flowing inside the heat transfer tube 2 can be performed for a long time. Become.

In the waste gas heat recovery device having the above structure, when the waste gas emitted when the operation of the engine or the like is started flows into the heat recovery chamber 1 through the waste gas introduction passage 11 and the waste gas inlet 10, the waste gas is discharged. The baffle 15 makes contact with the heat transfer tube 2 for a long time while changing its direction, exchanges heat with the cooling water flowing inside the heat transfer tube 2 and heats it, so that the thermal energy held by the waste gas is maintained. Is efficiently collected. The waste gas whose temperature has been lowered by heat exchange with the cooling water is exhausted from the waste gas outlet 12 and the waste gas exhaust passage 14.

In the above heat recovery, the waste gas is supplied to the heat recovery chamber 1
When the temperature of the cooling water flowing through the heat transfer tube 2 and the temperature of each part of the waste gas heat recovery unit are lower than the design temperature when the water starts flowing into the heat transfer tube, the water vapor contained in the waste gas is condensed on the surface of the heat transfer tube 2 and the bottom plate 8 The water dropped on the upper surface becomes drain water, flows into the waste gas drain chamber 7 through the opening 9, and is stored therein.

However, the temperature of the cooling water flowing through the heat transfer tube 2 and the temperature of each part of the waste gas heat recovery unit rise with the passage of time and reach the design temperature, so that the drain water in the heat recovery chamber 1 reaches the design temperature. The generation of the drain water does not occur, and the drain water does not flow into the waste gas drain chamber 7.

On the other hand, in the waste gas drain chamber 7, the heating action via the wall surface (usually made of iron) of the high-temperature waste gas flowing through the waste gas introduction passage 11 and flowing into the heat recovery chamber 1 always works. As a result, the temperature of the drain water flowing into and stored in the waste gas drain chamber 7 gradually increases, and finally evaporates.

Further, since the waste gas introduction passage 11 is provided on the deepest side of the waste gas drain chamber 7, the drain water flowing into the waste gas drain chamber 7 evaporates to the last one drop, and the opening 9 The waste gas is discharged together with the waste gas via the heat recovery chamber 1 and the waste gas outlet 12.

For this reason, in the waste gas heat recovery unit having the above structure according to the present invention, if the internal volume of the waste gas drain chamber 7 is sufficiently secured, it is not necessary to connect a drain water pipe or the like to the waste gas drain chamber 7. .

(Embodiment 2) A second embodiment of the present invention will be described with reference to FIG. Parts having the same functions as those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals also in FIG. 2, and description thereof will be omitted within a range that does not hinder the understanding of the present invention.

In the waste gas heat recovery unit of the second embodiment, the bottom plate 16 of the waste gas drain chamber 7 is installed in parallel with the bottom plate 8 of the heat recovery chamber 1, and the first embodiment shown in FIG. A waste gas exhaust passage 14 penetrating the inside of the waste gas drain chamber 7 as described above is attached to the outer surface of the bottom plate 16.

For this reason, in this waste gas heat recovery unit, the drain stored in the waste gas drain chamber 7 due to the high temperature waste gas flowing through the waste gas introduction passage 11 and flowing into the heat recovery chamber 1. There is an advantage that the effect of heating and evaporating water is larger than that of the waste gas heat recovery device of the first embodiment.

Since the present invention is not limited to the above embodiment, various modifications can be made without departing from the spirit of the appended claims. For example, in the second embodiment, as shown by a broken line in FIG. 2, it is possible to provide the waste gas introduction passage 11 so as not to penetrate the waste gas drain chamber 7. With such a configuration, the manufacture and maintenance of the apparatus are facilitated, but the above-described effects are smaller than when the apparatus is penetrated. It is also possible to adopt a vertical type or a structure in which a steam separator is attached to a waste gas outlet.

[0028]

As described above, according to the present invention, waste gas emitted from an engine driven by using gas or oil as fuel is brought into thermal contact with a cooling fluid via a heat transfer tube, and the waste gas has A waste gas heat recovery unit that transfers heat energy to a cooling fluid to recover heat

A waste gas drain chamber which is partitioned from the heat recovery chamber via a bottom plate having an opening of the heat recovery chamber accommodating the heat transfer tube, and which communicates only with the heat recovery chamber, is provided below the heat recovery chamber; A waste gas heat recovery unit provided in the waste gas drain chamber through a waste gas passage for guiding waste gas to the heat recovery chamber;

Further, since the waste gas passage is a waste gas heat recovery device provided outside the waste gas drain chamber,

Even if the steam contained in the waste gas condenses at the start of heat recovery where the temperature of each part of the cooling fluid or the waste gas heat recovery unit is low and becomes drain water and flows into the waste gas drain chamber, it takes a long time. When the temperature of the cooling fluid flowing in the heat transfer tube and each part of the waste gas heat recovery unit rises after the elapse of, the water vapor contained in the waste gas does not condense.

The drain water flowing into and stored in the waste gas drain chamber evaporates due to the heating action of the waste gas flowing into the heat recovery chamber through the waste gas passage, so that the drain water is discharged into the waste gas drain chamber. There is no need to install pipes for installation.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a first embodiment.

FIG. 2 is an explanatory diagram of a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat recovery room 2 Heat transfer tube 3 Cooling water inlet 4.5 header 6 Cooling water outlet 7 Waste gas drain room 8 Bottom plate 9 Opening 10 Waste gas inlet 11 Waste gas introduction passage 12 Waste gas outlet 13 Top plate 14 Waste gas exhaust passage 15 Baffle 16 bottom plate

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 63-100625 (JP, U) JP-A 3-108815 (JP, U) JP-A 63-46621 (JP, U) (58) Survey Field (Int.Cl. ⁷ , DB name) F01N 5/02 F28D 7/16

Claims (2)

(57) [Claims] A combustion gas (hereinafter referred to as waste gas) emitted from an engine driven by using gas or oil as a fuel is brought into thermal contact with a cooling fluid via a heat transfer tube, and heat generated by the waste gas is retained. In a waste gas heat recovery unit for transferring energy to a cooling fluid for heat recovery, the waste gas heat recovery unit is partitioned from the heat recovery chamber through a bottom plate having an opening of the heat recovery chamber that houses the heat transfer tube,
A waste gas drain chamber communicating only with the heat recovery chamber is provided below the heat recovery chamber, and a waste gas passage that guides waste gas to the heat recovery chamber is provided in the waste gas drain chamber. And waste gas heat recovery unit. 2. A combustion gas (hereinafter referred to as waste gas) emitted from an engine driven by using gas or oil as a fuel and a cooling fluid are brought into thermal contact with each other through a heat transfer pipe, and heat generated by the waste gas is retained. In a waste gas heat recovery unit for transferring energy to a cooling fluid for heat recovery, the waste gas heat recovery unit is partitioned from the heat recovery chamber through a bottom plate having an opening of the heat recovery chamber that houses the heat transfer tube,
A waste gas drain chamber communicating only with the heat recovery chamber is provided below the heat recovery chamber, and a waste gas passage for guiding waste gas to the heat recovery chamber is provided outside the waste gas drain chamber. And waste gas heat recovery unit.