JP3463895B2 - Drain discharge device of steam heat source heat exchanger - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drain discharge device for a steam heat source heat exchanger used in, for example, an external conditioner.

[0002]

2. Description of the Related Art In order to heat the interior of a building, for example, an external air conditioner is installed, and a steam heat source heat exchanger using steam as a heat source is used as one of the heat exchangers of this outdoor air conditioner. In the steam heat source heat exchanger, heat is exchanged between steam and air, but it is required that the drain does not stay inside.

3 and 4 show an example of an external air conditioner and a steam heat source heat exchanger provided in the external air conditioner. In FIG. 3, reference numeral 101 denotes an external air conditioner, which is attached to the wall 102. The external air conditioner 101 has a casing 103, and in the inside 103 of the casing 103, a steam heat source heat exchanger 104 and a cooling coil 105 which is a part of a refrigeration cycle system.
And a filter 105A is arranged on the upstream side of the cooling coil 105, and the steam heat source heat exchanger 1
A humidifier 105B and a blower 105C are arranged on the downstream side of 04. The casing 103 is formed with an outlet 103A and an inlet 103B.

As shown in FIG. 4, the steam heat source heat exchanger 104 is arranged as a part of the high temperature water circulating device 106, and includes a horizontal steam coil 109 arranged between a pair of side tanks 107 and 108. Have

One end of a steam pipe 110 is connected to one side tank 107 of the steam heat source heat exchanger 104, and the upper end of a boiler 111 is connected to the other end of the steam pipe 110. A return water pipe 112 is connected to the bottom of the boiler 111,
A water supply pump 113A and a return water tank 113B are attached to the return water pipe 112. A two-way valve 110A is attached to the steam pipe 110.

A steam trap 114 is connected to the lower side portion of the other side tank 108 of the steam heat source heat exchanger 104. The steam trap 114 separates steam and condensed water in the return water pipe 112,
It is for passing only condensed water to the downstream side of No. 4.

[0007]

However, in the conventional steam heat source heat exchanger 104, when the partial load operation is performed due to its control characteristics, the steam heat source heat exchanger 104 supplies steam to the steam for condensation of steam. Steam heat source heat exchanger 1
The pressure inside 04 becomes lower than atmospheric pressure. This low pressure is 40 ℃
In the case of air heating at -50 ° C, assuming that there is no drain retention area, 650 mmHg (8
It is a low value of about 6659 Pa), which is a low pressure that cannot be discharged by a vacuum pump of normal capacity.

Therefore, during the partial load operation of the steam heat source heat exchanger 104, a drain retention region is generated inside the steam heat source heat exchanger 104. In such a horizontal-type steam heat source heat exchanger 104, the drain inside the steam heat source heat exchanger 104 is the other tank body 108 of the steam heat source heat exchanger 104.
On the bottom 108A of the steam coil 109 and on the bottom 109A of the steam coil 109
Will accumulate on top. Therefore, the steam heat source heat exchanger 1
The effective heat transfer area of the steam coil 109 of No. 06 is reduced, and the internal pressure of the steam heat source heat exchanger 106 is increased by that amount to achieve balance and heat exchange.

Even in such a state, the amount of heat exchange is satisfactory, but since the effective heat transfer area of the steam coil 109 is small, the amount of heat exchange is small and even if an attempt is made to change the temperature change of air, It is considered to have poor controllability.

Further, in the external air conditioner 101, there is a problem in that the temperature of the air becomes uneven, the amount of heat in the air distribution on the downstream side of the steam coil 109 becomes uneven, and dew condensation occurs due to oversaturation of humidification.

It is also a cause that the steam coil 109 is damaged by freezing of the drain water retained therein when it is extremely cold. The present invention has been made to solve the above-mentioned problems, and an object thereof is to prevent the drain of the steam coil from remaining in the steam heat source heat exchanger even in a partial load operation of the steam heat source heat exchanger. An object of the present invention is to provide a heating air conditioner capable of preventing uneven heat distribution of air distribution on the downstream side and generation of dew condensation and avoiding damage due to freezing of water inside the steam coil.

[0012]

The invention according to claim 1 is
A boiler, a steam pipe connected to the boiler, a steam heat source heat exchanger having a vertical steam coil for heat exchange between steam and air from the steam pipe, and an upper end at the bottom of the steam heat source heat exchanger. The connected drain pipe and the water surface of the drain are located below the bottom of the steam heat source heat exchanger within the maximum allowable drain flow height, and the lower end of the drain pipe is constantly immersed below the water surface of the drain. And a return water pipe connected to the drain tank for discharging the drain.

According to a second aspect of the present invention, in the drain discharge device of the steam heat source heat exchanger according to the first aspect, the water level of the drain in the drain tank is 1 more than the bottom of the steam heat source heat exchanger.
It is characterized in that it is located about 0 m below.

[0014]

In the invention of claim 1, since the water surface of the drain is located below the bottom of the steam heat source heat exchanger within the range of the maximum allowable drain flow height, the inside of the steam heat source heat exchanger is The sum of the pressure and the drain pressure at the drain flow height in the drain pipe is balanced with the atmospheric pressure that presses the water surface of the drain in the drain tank, and the pressure inside the steam heat source heat exchanger is lower than atmospheric pressure.

When the drain collects in the steam coil of the steam heat source heat exchanger, the pressure in the steam coil increases and the drain in the steam coil flows out into the drain pipe. Therefore, the drain produced by condensing in the steam coil of the steam heat source heat exchanger flows down to the drain tank via the drain pipe without staying inside.

Since the lower end of the drain pipe is always immersed below the surface of the drain of the drain tank, the inside of the drain pipe and the inside of the drain tank communicate with each other via the drain. In the invention according to claim 2, since the water surface of the drain in the drain tank is located about 10 m below the bottom of the steam heat source heat exchanger, the inside of the steam heat source heat exchanger is set to a pressure close to a vacuum, Drain can be reliably discharged from the steam coil of the steam heat source heat exchanger.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a drain discharge device of a steam heat source heat exchanger according to an embodiment of the present invention.

In FIG. 2, reference numeral 1 is an external air conditioner, which is attached to a wall 2. The external air conditioner 1 has a casing 3, a steam heat source heat exchanger 4 and a cooling coil 5 that is a part of a refrigeration cycle system are arranged inside the casing 3, and further on the upstream side of the cooling coil 5. A filter 5A is arranged, and a humidifier 5B and a blower 5C are arranged downstream of the steam heat source heat exchanger 4. Casing 3
An air outlet 3A and a suction port 3B are formed in this.

As shown in FIG. 1, the steam heat source heat exchanger 4 is constructed as a part of the high temperature water circulation device 6, and is arranged between the upper tank portion 7 and the lower tank portion 8 in a plurality of vertical types. It has a steam coil 9.

One end of the steam pipe 10 is connected to the upper tank portion 7 of the steam heat source heat exchanger 4, and the upper end of the boiler 11 is connected to the other end of the steam pipe 10. A return water pipe 12 is connected to a lower portion of the boiler 11, and the return water pipe 12 is equipped with a water supply pump 13A and a return water tank 13B. In addition,
A two-way valve 10A is attached to the steam pipe 10.

The upper end 14A of the drain pipe 14 is connected to the bottom 8A of the lower tank portion 8 of the steam heat source heat exchanger 4. The drain tank 15 is arranged such that the water surface 15A of the drain is located below the bottom 8A of the steam heat source heat exchanger 4 within the range of the maximum allowable drain flow height.
Below the water surface 15A of the drain inside, the lower end 14B of the drain pipe 14
Is always immersive. The maximum allowable drain flow height is the height from the water surface 15A of the drain in the drain tank 15 to the water surface 9A of the drain in the steam coil 9 of the steam heat source heat exchanger 4, and a drain flow can be formed in the drain pipe 14. The maximum height. Then, the drain water surface 1 in the drain tank 15
5A is located about 10 m below the bottom 8A of the steam heat source heat exchanger 4.

Next, the operation of this embodiment will be described. The two-way valve 10A is opened during normal operation of the high-temperature water circulating device 6. Since the water surface 15A of the drain in the drain tank 15 is located below the bottom 8A of the steam heat source heat exchanger 4 within the range of the maximum allowable drain flow height, the internal pressure of the steam heat source heat exchanger 4 is The sum of the drain pressure at the drain flow height in the drain pipe 14 is balanced with the atmospheric pressure that presses the water surface 15A of the drain in the drain tank 15, and the pressure inside the steam heat source heat exchanger 4 is lower than the atmospheric pressure, and the vacuum is generated. Is close to.

Therefore, when the drain is accumulated in the steam coil 9 of the steam heat source heat exchanger 4, the drain in the steam coil 9 is discharged into the drain pipe 14. The drain always flows into the drain tank 15 through the drain pipe 14. That is, the drain inside the steam coil 9 is discharged from the inside of the steam coil 9 into the drain tank 1
Flows while being discharged into 5.

The outside air is sucked into the suction port 3B of the external air conditioner 1 of FIG. 2, and the outside air is heat-exchanged by the condensation of the steam in the steam heat source heat exchanger 4 to give heat, and the temperature rises, It becomes warm air and is blown out into the room from the air outlet 3A of the external air conditioner 1. At the same time, due to the cooling of the outside air, part of the vapor is condensed into a gas-liquid fluid. The gas-liquid fluid is a mixture of steam and drain (condensed water). The steam is used for the boiler 11
Through the steam pipe 10 to the steam heat source heat exchanger 4.

The gas-liquid fluid is guided to the drain tank 15 through the drain pipe 14. The drain generated in the steam heat source heat exchanger 4 is stored in the drain tank 15. Further, the drain is drain tank 15 → return water pipe 12 → return water tank 13
B → water supply pump 13A → boiler 11 in this order, boiler 1
1 and becomes steam in the boiler 11. In this way
The drain (steam) circulates in the high temperature water circulation device 6.

The lower end 14B of the drain pipe 14 is placed on the water surface 1 so that the drain in the drain tank 15 is not broken.
Immersed under 5A. According to the configuration as described above, the drain tank 15 has the bottom portion 8 of the steam heat source heat exchanger 4.
The drain water surface 15A is located below the drain water surface 15A within the maximum allowable drain flow height.
Since the lower end 14B of the drain pipe 14 is constantly immersed, the drain condensed in the steam coil 9 of the steam heat source heat exchanger 4 does not stay inside and is drained to the drain tank 15 via the drain pipe 14. Can be washed away.

As a result, the drain is used as the steam heat source heat exchanger 4
The steam coil 9 can be drawn into the drain tank 15, and the drain can be prevented from staying in the steam heat source heat exchanger 4.

Therefore, during the partial load operation of the steam heat source heat exchanger 4, even if the pressure inside the steam heat source heat exchanger 4 becomes low, it is possible to prevent the occurrence of a drain retention area inside the steam heat source heat exchanger 4. . As a result, the amount of heat exchange can be secured and the controllability of air temperature changes can be improved without reducing the effective heat transfer area of the steam coil 9 of the steam heat source heat exchanger 4.

Further, the temperature distribution of the air at the outlet of the steam heat source heat exchanger 4 is made uniform, and the unevenness of the temperature of the air is not generated. Condensation can be reduced.

Further, when it is extremely cold, the steam heat source heat exchanger 4 is used.
Since the drain does not stay inside, damage due to freezing of water inside the steam coil 9 can be avoided. Although the drain in the return water pipe 12 returns to the boiler 11 in the present embodiment, it can be discharged from the return water pipe 12 to the outside.

[0031]

As described above, according to the invention described in claim 1, the drain tank is positioned below the bottom of the steam heat source heat exchanger within the maximum allowable drain flow height range. Since the lower end of the drain pipe is always immersed under the water surface of the drain, the drain condensed through the steam coil of the steam heat source heat exchanger does not stay inside and the drain pipe is drained through the drain pipe. Can be drained to the tank.

As a result, the drain can be drawn into the drain tank from the steam coil of the steam heat source heat exchanger,
Drain can be prevented from accumulating in the steam heat source heat exchanger. Therefore, during the partial load operation of the steam heat source heat exchanger, even if the pressure inside the steam heat source heat exchanger becomes low, it is possible to prevent the occurrence of a drain retention area inside the steam heat source heat exchanger. As a result, the amount of heat exchange can be secured and the controllability of the temperature change of air can be improved without reducing the effective heat transfer area of the steam coil of the steam heat source heat exchanger.

Further, the air temperature distribution at the outlet of the steam heat source heat exchanger is made uniform, and the unevenness of the air temperature is not generated. Can be reduced.

Further, when the temperature is extremely cold, the drain does not stay in the heat exchanger of the steam source, so that the damage due to the freezing of the water inside the steam coil can be avoided. According to the invention of claim 2, since the water surface of the drain in the drain tank is located below the bottom of the steam heat source heat exchanger by about 10 m, the pressure inside the steam heat source heat exchanger is close to a vacuum. The drain can be reliably discharged from the steam coil of the steam heat source heat exchanger.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a drain discharge device of a steam heat source heat exchanger according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of an external air conditioner provided with the same steam heat source heat exchanger.

FIG. 3 is a configuration diagram of a conventional external air conditioner.

FIG. 4 is a configuration diagram of a drain discharge device of a conventional steam heat source heat exchanger.

[Explanation of symbols]

4 Steam heat source heat exchanger 8A bottom 9 steam coil 10 Steam piping 11 boiler 12 Return pipe 14 Drain pipe 14A upper end 14B bottom 15 drain tank 15A water surface

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F24D 7/00 F16T 1/00 F24D 1/08 F24D 19/08

Claims (2)

(57) [Claims] 1. A steam heat source heat exchanger having a boiler, a steam pipe connected to the boiler, a vertical steam coil for heat exchange between steam and air from the steam pipe, and a steam heat source heat exchanger. The drain pipe whose upper end is connected to the bottom of the steam heat source heat exchanger and the drain water surface are located below the bottom of the steam heat source heat exchanger within the maximum allowable drain flow height. A drain discharge device for a steam heat source heat exchanger, comprising a drain tank whose lower end is constantly immersed, and a return water pipe connected to the drain tank to discharge the drain. 2. The drain discharge device for a steam heat source heat exchanger according to claim 1, wherein the water level of the drain in the drain tank is located about 10 m below the bottom of the steam heat source heat exchanger.