JPH07225055A - Heat refrigerant boiler - Google Patents

Abstract

PURPOSE:To achieve miniaturization of a boiler by improving a heat transfer factor without increasing film temperature limited by deterioration temperature of a heat refrigerant fluid and reducing a heat transfer area (particularly a heat transfer area in a high temperature region). CONSTITUTION:A heat refrigerant boiler is constructed such that it has a can structure including a radiation transfer part for mainly receiving radiation transfer heat from hot gas produced by a burner 14 and it includes a heat transfer tube 1 located in a radiation heat transfer part as a grooved pipe having a groove 2 in an internal peripheral surface. Further the boiler has a can structure including a contact heat transfer part for receiving contact transfer heat mainly from hot gas derived from the radiation heat transfer part. At least the heat transfer tube 1 located in the radiation heat transfer part is constructed as a structure where it is a grooved pipe having a groove 2 in an internal peripheral surface. A more concrete can structure is provided such that the heat transfer pipe 1 is spiratlly wound into a single cylinder or multiple cylinders having different wind-up diameters, and an innermost peripheral space is constructed as a combustion chamber 13 and a heat transfer pipe part facing the combustion chamber 13 is constructed as the radiation heat transfer part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called heat medium boiler, which heats a heat medium liquid such as oil used under relatively high temperature working conditions such as chemical reaction work and plastic molding work. More specifically, the present invention relates to a can body structure of a heating medium boiler.

[0002]

2. Description of the Related Art A general boiler heats water and uses it as steam or hot water as a heat source directly or indirectly, but a heat medium boiler is a heat medium liquid such as oil. Is heated, and this heat transfer liquid is used as a heat source. This is because when steam or hot water is supplied to a place where a high temperature heat source is required, the pressure becomes too high, and therefore a heat medium having a relatively low pressure is used even at a high temperature to supply at a low pressure.

[0003]

By the way, such a heat medium liquid is deteriorated by oxidation or polymerization at a high temperature to cause a decrease in specific heat and an increase in viscosity.
Problems such as blockage of heat transfer medium flow passages such as heat transfer pipes and piping occur, and further, operation of the boiler becomes impossible. Therefore, it is necessary to regularly replace the expensive heat transfer fluid. In order to prevent such deterioration of the heat transfer fluid, the flow velocity of the heat transfer fluid in the heat transfer tube is increased.However, in order to suppress the film temperature of the heat transfer fluid on the surface of the heat transfer tube, There is a limit to the improvement of. That is, the amount of heat received per unit area on the heat receiving surface of the heat transfer tube is limited by the factor of high temperature deterioration of the heat transfer medium. (Here, the film temperature is the temperature at the surface of the heat transfer surface of the fluid that transfers heat from the heat transfer surface,
The boundary film temperature is extremely close to the surface temperature of the heat transfer surface, and changes rapidly as the distance from the heat transfer surface increases. )

Such a limitation of the heat transfer surface load is remarkable particularly in a combustion chamber for generating hot gas or in a space having a high temperature such as a place where the hot gas is introduced, and as a result, the space volume must be increased. I don't get. (Here, the hot gas includes a combustion flame and a relatively high-temperature gas body containing the combustion gas, and the combustion gas also includes those until the combustion is completed.)

That is, the heat transfer coefficient from the heat transfer tube to the heat transfer liquid is limited as described above, and in order to miniaturize the heat absorbing portion, the heat transfer coefficient is improved without increasing the film temperature. It is impossible to do. Therefore, in the conventional heat medium boiler, the heat transfer area, particularly the heat transfer surface area in the high temperature region, has to be widened, which increases the volume of the combustion chamber, making it impossible to downsize the boiler can. .

[0006]

SUMMARY OF THE INVENTION In view of the above problems, the present invention has been made to provide a small-sized and highly efficient heat transfer medium boiler, which mainly emits radiation from hot gas generated by a burner. It has a can body structure having a radiant heat transfer section for receiving heat, and the heat transfer tube located in the radiant heat transfer section is a grooved tube having a groove on the inner peripheral surface, which is a first characteristic,
Further, it has a can body structure including the radiant heat transfer section and a contact heat transfer section that mainly receives contact heat from the hot gas derived from the radiant heat transfer section, and has a can structure located at least in the radiant heat transfer section. It is a heat medium boiler having a second feature that the heat pipe is a grooved pipe having a groove on its inner peripheral surface.

Furthermore, the can body structure of the heat medium boiler has a tubular shape in which a heat transfer tube is spirally wound, and a burner is arranged so as to face the innermost peripheral space thereof, and this space is used as a combustion chamber. Thus, the third feature is that the heat transfer tube portion facing the combustion chamber is a radiant heat transfer section, and the heat transfer tube is spirally wound into a plurality of tubular shapes with different winding diameters. None, by arranging the burner in the innermost peripheral space part to make this space part a combustion chamber, the heat transfer pipe part facing this combustion chamber is made a radiant heat transfer part, and multiple cylindrical heat transfer parts are formed. A heat transfer medium boiler having a fourth feature that a heat transfer tube portion facing the clearance is a contact heat transfer surface by forming a gap between the heat tube portions for flowing hot gas from the combustion chamber. Is.

[0008]

With the heating medium boiler according to the present invention, since the contact area of the heating medium liquid in the heat transfer tube can be increased, the film temperature for the same heating amount is lowered. In other words, the heat transfer surface load can be increased when the film temperature is the same. In addition, in the can body structure that incorporates the radiant heat transfer part and the contact heat transfer part, the size of the part that receives the radiant heat transfer from the hot gas reduces the temperature of the hot gas without significantly decreasing the temperature inside the contact heat transfer part. Since it flows into, the heat recovery can be efficiently performed even in the contact heat transfer section, and the heat recovery amounts in the radiant heat transfer section and the contact heat transfer section are more averaged.

Specifically, the heat transfer tube is spirally wound and
In the case of a heating medium boiler having a can structure having a heavy or multiple cylindrical shape with different winding diameters, and the innermost peripheral space portion thereof being the combustion chamber as the radiant heat transfer portion, the surface of the combustion chamber is Since the area of the heat transfer surface of the radiant heat transfer section can be reduced, the capacity of the combustion chamber can be inevitably reduced.Furthermore, the spirally wound heat transfer tube has a multiple cylindrical shape, and each cylindrical shape part In the case of a can body structure in which a contact heat transfer part is formed between them, the heat transfer surface area of the contact heat transfer part into which the hot gas from the combustion chamber flows is enlarged, but the heat transfer surface as a whole. Area shrinks.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a heating medium boiler having a can body structure formed by spirally winding a heat transfer tube, a so-called monotube type can body structure will be described with reference to FIGS. To do. First, the illustrated heat transfer medium boiler (A) is provided with double cylindrical heat transfer tube walls (11) and (12) by spirally winding a heat transfer tube (1) through which a heat transfer medium flows. It constitutes a can body (10).

Of the double cylindrical heat transfer tube walls (11) and (12), a casing (16) that forms the outer shape of the boiler is arranged on the outer circumference of the outer heat transfer tube wall (12). I am doing it. This casing
A heat insulating material layer (17) is formed between (16) and the can body (K),
The upper and bottom openings of the can body (10) are closed, and a burner (14) is attached to one end (upper end in the illustrated embodiment) of the space surrounded by the inner heat transfer tube wall (11). The combustion chamber (13) is arranged by arranging it so as to face the space substantially coaxially.
Are configured. Further, the cylindrical gap (15) formed between both heat transfer tube walls (11) and (12) communicates with the lower part of the combustion chamber (13), and the burner (14) in the combustion chamber (13) is The hot gas generated by) flows in. Then, the hot gas is
After passing 5), it is discharged to the outside of the system via an exhaust means such as a chimney, or is discharged to the outside of the system after passing through a heat recovery means such as an economizer. In addition, in this embodiment, a gap is formed between the heat transfer tubes (1) by widening the winding pitch of the heat transfer tubes (1) in the lower part of the inner heat transfer tube wall (11),
Heat gas is circulated into the gap (5) through this gap and the gap between the heat transfer tube wall (11) and the heat insulating material layer (17). Gas inner heat transfer tube wall
It may be configured to flow into the gap (5) only through the gap between the lower end of (11) and the heat insulating material layer (17). Therefore, the surface of the heat transfer tube (1) of the heat transfer tube wall (11) facing this combustion chamber (13) is
The radiant heat transfer section that mainly receives radiant heat transfer
The surface of the heat transfer tube (1) of the heat transfer tube wall (11) (12) facing (15) is
The contact heat transfer section mainly receives the contact heat transfer.

As shown in the enlarged view of FIG. 2, the heat transfer tube (1) is a grooved tube in which a large number of grooves (2) along the axial direction thereof are formed, and the grooves (2) are It may be in the same direction as the inner peripheral surface of the heat transfer tube (1), or may be formed with an appropriate turning angle like a rifle groove. In the latter case, inside the heat transfer tube (1) A swirl flow in the flow direction can be given to the heat transfer liquid flowing in the heat transfer liquid, and the heat transfer liquid in the heat transfer tube (1) can be heated more uniformly. Furthermore, this groove
Even if it is formed continuously in the axial direction of the heat transfer tube,
It may be formed by appropriately dividing and shifting the phase with respect to the axis. Heat transfer tube with grooved tube (1)
As described later, may be at least the heat transfer tube (1) constituting the inner heat transfer tube wall (11), that is, the part of the heat transfer tube (1) located in the radiant heat transfer section, and more preferably. Is preferably provided in the heat transfer tube portion corresponding to the radiant heat transfer section, and more preferably, it is provided in a location where the heat load from the hot gas to the heat transfer tube is large, and the film temperature of the heat transfer medium in the entire heat transfer tube is It is preferable that the heat transfer liquid is set to be substantially constant within the heat-resistant temperature limit of the heat transfer liquid, and the cost can be reduced as compared with the case where the entire heat transfer pipe is a grooved pipe.

The flow of the heat transfer liquid in the heat transfer boiler is the heat transfer tube (1) located at the upper end of the inner heat transfer tube wall (11).
Inflow from the open end of the heat transfer tube wall (11)
After swirling (1) spirally and flowing downward,
After spirally swirling from below the outer heat transfer tube wall (12) and flowing upward, the heat transfer tube (1) located at the upper end of the outer heat transfer tube wall (12) It flows out from the open end. Generally, the heat medium liquid heated by such a heat medium boiler utilizes its heat energy at a demand point, and the heat medium liquid having a lowered temperature is circulated and supplied again to the heat medium boiler.

In the heat medium boiler having such a can structure, the surface of the heat transfer tube in the radiant heat transfer section facing the combustion chamber (13) receives radiant heat from the hot gas, and the gap (15) The surface of the heat transfer tube in the contact heat transfer section facing the main part receives contact heat transfer, and these heats are transferred to the internal heat transfer medium via the tube wall of the heat transfer tube (1) itself.

In the heat transfer process by the radiative heat transfer from the hot gas and the contact heat transfer, the outer surface of the heat transfer tube (1) is a smooth cylindrical surface, and the inner surface is formed with the groove as described above. Therefore, the heat transfer area to the heat transfer liquid becomes wider than that of the conventional cylindrical surface shape. Therefore, when the same amount of heat is received from the hot gas on the outer surface of the heat transfer tube (1), the temperature on the inner surface of the heat transfer tube (1) decreases, and the film temperature of the heat transfer medium in contact with the inner surface also decreases.

That is, the boundary film temperature of the heat transfer liquid is limited by the deterioration temperature of the heat transfer liquid as described above. Since the thermal surface load can be increased, more heat transfer can be performed due to the smaller heat transfer area. Therefore, in the case of the heating medium boiler having the same capacity, it is possible to downsize the boiler and improve the efficiency by reducing the heat transfer area. In particular, as for the effect of reducing the size of the can body by reducing the heat transfer area, the effect of reducing the size of the heat transfer portion (heat gas generating portion such as the combustion chamber) most heated by the heat gas is remarkable.

Further, in the can body structure in which the radiant heat transfer section and the contact heat transfer section are incorporated as in the above-mentioned embodiment, the temperature of the hot gas is significantly lowered due to the miniaturization of the radiant heat transfer section. Instead, it flows into the contact heat transfer section. Therefore, even if the heat transfer surface area of this portion is expanded in order to average the amount of heat recovery in the contact heat transfer part into which the hot gas from the combustion chamber flows, the heat transfer surface area as a whole is reduced. To do. Therefore, it is possible to provide a more compact and highly efficient heat medium boiler at low cost as a whole.

In addition to the can body structure as shown in the illustrated embodiment, the same can be applied to a can body structure in which a heat transfer tube is wound in a single cylindrical shape and the inside thereof is a combustion chamber. ,
In this case, it is preferable to form a groove on the inner surface of the portion that is heated by the hot gas from the burner.

Further, according to the present invention, in addition to the heating medium boiler having a can body structure in which the heat transfer tubes are spirally wound as described above, a multi-tube type water tube boiler type in which a large number of heat transfer tubes are arranged is also used. The same can be applied to the case structure. As an example of such a multi-tube boiler can, a large number of vertical heat transfer tubes are annularly arranged to form one to multiple annular heat transfer tube walls, and the innermost peripheral portion of the annular heat transfer tube wall is formed. With a combustion chamber,
In the hot gas flow path that extends from the burner in a substantially straight line, a number of vertical water pipes are arranged parallel to each other so as to intersect with this flow path, and the upper and lower end parts of each vertical heat transfer pipe are used as headers. In these can body structures, in the former case, the surface of the heat transfer tube facing the combustion chamber is the radiant heat transfer section, and in the case of the latter, other than the surface of the heat transfer tube directly facing the burner. The surface of the heat transfer tubes on the downstream side also corresponds, and grooves are formed on the inner peripheral surfaces of these heat transfer tubes.

Even when applied to such a heating medium boiler having a can body structure, the efficiency of the heating medium boiler can be increased or the size thereof can be reduced, and the heat transfer area can be reduced. The miniaturization effect of the can body due to is remarkable in miniaturization in the heat transfer portion (heat gas generation portion such as the combustion chamber) that is most heated by the hot gas. In addition, in the can body structure that incorporates the contact heat transfer part in the wake of the radiant heat transfer part, the contact heat transfer can be performed without the temperature of the hot gas significantly decreasing due to the miniaturization of the radiant heat transfer part of the hot gas. Since it flows into the heat transfer section, efficient heat recovery can be performed even in the contact heat transfer section, and the heat recovery amounts in the radiant heat transfer section and the contact heat transfer section are more averaged. Therefore, it is possible to provide a more compact and highly efficient heat medium boiler at low cost as a whole.

[0021]

As described above, according to the heating medium boiler of the present invention, the film temperature of the heating medium liquid on the surface of the heat transfer tube can be lowered for the same heating amount. Since the heat transfer surface load with the hot gas can be increased when the film temperature is the same, more heat can be transferred by the narrower heat transfer area.

Therefore, it is possible to improve the efficiency of the heat medium boiler or to downsize it, and the effect of downsizing the can body by reducing the heat transfer area is that the heat gas is most heated. The effect of miniaturization in the heat part (the part that generates hot gas such as the combustion chamber) is remarkable.

Further, in the can body structure in which the radiant heat transfer section and the contact heat transfer section are incorporated, the size of the portion receiving the radiant heat transfer from the hot gas causes the hot gas to contact without significantly lowering the temperature. Since it flows into the heat transfer section, efficient heat recovery can be performed even in the contact heat transfer section, and the heat recovery amounts in the radiant heat transfer section and the contact heat transfer section are more averaged. Therefore, it is possible to provide a more compact and highly efficient heat medium boiler at low cost as a whole.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view illustrating a can body structure in an embodiment of a heat medium boiler according to the present invention.

FIG. 2 is a cross-sectional view showing an example of a water pipe applied to the boiler can body of the heat medium boiler shown in FIG.

[Explanation of symbols]

 (1) Heat transfer tube (2) Groove (10) Can body (11) Heat transfer tube wall (inner cylindrical heat transfer tube wall) (12) Heat transfer tube wall (outer cylindrical heat transfer tube wall) (13 ) Combustion chamber (14) Burner (15) Gap (A) Heat medium boiler

Claims (4)

[Claims] 1. A heat transfer tube (1) having a can body structure having a radiant heat transfer part for mainly receiving radiative heat transfer from hot gas generated by a burner (14), the heat transfer tube (1) being located in the radiant heat transfer part. A heat medium boiler characterized by being a grooved tube having a groove (2) on the inner peripheral surface. 2. A radiant heat transfer section that mainly receives radiant heat transfer from the hot gas generated by the burner (14), and a contact heat transfer section that mainly receives contact heat transfer from the hot gas derived from this radiant heat transfer section. A heat transfer medium boiler having a can body structure including: a heat transfer tube (1) located at least in a radiant heat transfer section being a grooved tube having a groove (2) on an inner peripheral surface thereof. 3. A can body structure of the heating medium boiler is a heat transfer tube.
(1) is spirally wound into a cylindrical shape, and the burner (14) is arranged facing the innermost peripheral space of this, and this space is set in the combustion chamber (1
The heat medium boiler according to claim 1 or 2, wherein the heat transfer tube portion facing the combustion chamber (13) is a radiant heat transfer portion. 4. A heat transfer tube having a can structure of the heating medium boiler.
(1) is wound in a spiral shape to form multiple cylindrical shapes with different winding diameters, and the burner (14) is arranged facing the innermost space of this space, and this space is designated as the combustion chamber (13). By doing so, the heat transfer tube portion facing this combustion chamber (13) is formed as a radiant heat transfer portion,
By forming a gap between the multiple cylindrical heat transfer tube portions through which hot gas flows from the combustion chamber, the heat transfer tube portion facing this clearance (15) has a contact heat transfer surface. The heat medium boiler according to claim 1 or 2.