Heat exchange device having drain discharge mechanism

Abstract

To provide a heat exchanger having a drain discharge mechanism which can surely discharge drain.SOLUTION: When drain 60 stays in a steam pipe 6 of a heater 1 by surface tension, and a clogging state arises, a temperature sensor 28 detects the lowering of a temperature in an outlet-side header 3 caused by the clogging state. Then, an air valve 24 takes in a detection signal, and the air valve 24 is valve-opened at a time point at which a temperature of the air valve reaches a preset temperature, simultaneously releases an air supply line 16 and a second branch line 15, and supplies high-pressure air to an inlet-side header 2 through the air supply line 16. By this constitution, the drain 60 which is clogged in the steam pipe 6 is pressurized, the drain 60 falls down to the outlet-side herself 3, the clogging state is thus eliminated, and the drain is surely discharged.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The heat exchange device having a drain discharge mechanism according to the present application relates to a technique for discharging drain generated inside the device by heat exchange to the outside of the device. [Background technology]

[0002] An example of a heat exchange device with a drain discharge mechanism is a steam heat exchanger, which is an outdoor air processing air conditioner. This steam heat exchanger takes in high-temperature steam generated in a boiler and warms the outdoor air by exchanging heat between the steam and the outdoor air. This heat exchange causes the steam to condense, generating drain (condensed water). To ensure proper operation of the steam heat exchanger, the generated drain must be discharged to the outside by a discharge mechanism.

[0003] An example of such a drain discharge mechanism for a heat exchanger is a drain discharge device for a steam heat source heat exchanger disclosed in the below-mentioned Patent Document 1. In the steam heat source heat exchanger 4 in which this drain discharge device is provided, a large number of vertical steam coils 9 are arranged between an upper header section 7 and a lower header section 8.

[0004] A drain pipe 14 is connected to the bottom 8A of the lower header 8 of the steam heat source heat exchanger 4. A first pumping trap 18 and a second pumping trap 22 are connected to a first branch pipe 16 and a second branch pipe 17 formed by branching off the drain pipe 14, respectively.

[0005] A first drain on-off valve 19 is provided in the first branch pipe 16, and the first pumping trap 18 has a first cooler 20, both ends of which are connected to a cooling source 21. A second drain on-off valve 23 is provided in the second branch pipe 17, and the second pumping trap 22 has a second cooler 24, both ends of which are connected to the cooling source 21.

[0006] Furthermore, a first pressure supply pipe 25 and a second pressure supply pipe 26 are connected to the first pumping trap 18 and the second pumping trap 22, respectively. A first switching valve 27 and a second switching valve 28 are installed in the first pressure supply pipe 25 and the second pressure supply pipe 26, respectively. The first pressure supply pipe 25 and the second pressure supply pipe 26 branch off from one end of a pressure main pipe 29, and the other end of the pressure main pipe 29 is connected to the steam pipe 10.

[0007] In such a configuration, a combination of opening and closing of the first and second drain on-off valves 19, 23 and the first and second switching valves 27, 28 is selected depending on when drain is to be accumulated in the first pumping trap 18 and the second pumping trap 22 and when drain is to be discharged from the first pumping trap 18 and the second pumping trap 22, and when the steam heat source heat exchanger is in use (when drain is to be accumulated in the pumping traps), the inside of the first pumping trap 18 and the second pumping trap 22 is cooled to create a state close to a vacuum.

[0008] This makes the pressure inside the first pumping trap 18 and the second pumping trap 22 lower than the pressure inside the steam heat source heat exchanger, drawing the drain from the steam heat source heat exchanger into the first pumping trap 18 and the second pumping trap, and preventing the drain from accumulating in the steam heat source heat exchanger. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 8-94097 Summary of the Invention [Problem to be solved by the invention]

[0010] However, in the drain discharge device for the steam heat source heat exchanger disclosed in the above-mentioned Patent Document 1, the drain is drawn in by simply making the pressure inside the first pumping trap 18 and the second pumping trap 22 lower than that inside the steam heat source heat exchanger. Therefore, there is a problem that the drain generated in the steam coil 9 does not fall but remains there, and is not properly discharged from the steam heat source heat exchanger 4.

[0011] In particular, since the steam coil 9 is often configured as a thin tube to enable efficient heat exchange with the outside air, the surface tension of the drain inside the tube prevents the drain from falling, and the drain may remain inside the steam coil 9, causing clogging of the drain.

[0012] If drain clogging occurs in the steam coil 9, the heating capacity of the entire heat exchanger will decrease. In addition, there is a risk of water hammer occurring inside the heat exchanger due to drain retention caused by clogging.

[0013] In order to solve these problems, the heat exchanger having a drain discharge mechanism according to the present application has an object to provide a heat exchanger having a drain discharge mechanism that can reliably discharge drain. [Means for solving the problem]

[0014] A heat exchange device having a drain discharge mechanism according to the present application, A plurality of heating tubes having an inlet portion and an outlet portion, the heating tubes through which a heating fluid flows from the inlet portion toward the outlet portion; a drain discharge means for discharging drain generated from the heating fluid and falling along the heating tube to the outside; a detection means for detecting a fluctuation state which varies depending on a falling state of the drain in the drain pipe; a drain assisting means for introducing a drain fluid from an inlet portion into the drain pipe based on the fluctuation state of the drain pipe detected by the detection means, and promoting the fall of the drain; The present invention is characterized by comprising: Effect of the Invention

[0015] In the heat exchange device having the drain discharge mechanism according to the present application, the drain auxiliary means introduces a drain fluid from the inlet into the drain pipe based on the fluctuation state detected by the detection means, and promotes the fall of the drain. This promotes the fall of the drain in the drain pipe, and ensures that the drain is discharged. [Brief description of the drawings]

[0016] [Figure 1] 1 is a block diagram showing an overall configuration of a heater 1 illustrating a first embodiment of a heat exchanger having a drain discharge mechanism according to the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] [Terminology used in the embodiments] The main terms used in the embodiments correspond to the following elements of the heat exchange device having a drain discharge mechanism according to the present application. Heater 1: Heat exchanger Inlet header 2...Inlet section Exit side header 3···Exit section Steam pipe 6... Heating pipe Steam trap 22: drain discharge means Air valve 24 ···Ejection aid means Temperature sensor 28: detection means Temperature fluctuations in the outlet header 3 Air, nitrogen... Discharge fluid vapor··· heating fluid

[0018] [First embodiment] A first embodiment of a heat exchange device having a drain discharge mechanism according to the present invention will be described below. In this embodiment, a heater 1 is taken as an example of the heat exchange device.

[0019] (Explanation of heater 1 configuration) The heater 1 is equipped with a large number of steam pipes 6, and each steam pipe 6 is arranged vertically at a predetermined interval. The upper end of each steam pipe 6 is connected to the inlet header 2, and the lower end is connected to the outlet header 3. Each steam pipe 6 is in communication with the inlet header 2 and the outlet header 3.

[0020] A steam supply line 11 is connected to the inlet header 2, and steam is supplied to the inlet header 2 via a steam valve 21 provided on the steam supply line 11. A temperature sensor 28 is attached to the outlet header 3, which detects the temperature inside the outlet header 3 and outputs a temperature signal.

[0021] In addition, a drain discharge line 12 is connected to the outlet header 3, and a steam trap 22 is provided in this drain discharge line 12. In this embodiment, a float type steam trap is used as the steam trap 22. A float type steam trap has a hollow float built into the valve chest so that it can float freely, and when the drain that has flowed into the valve chest exceeds a certain water level, the float rises and opens the orifice, opening the valve and automatically discharging the drain to the outside.

[0022] An air discharge line 13 is connected to the outlet header 3, and this air discharge line 13 branches into a first branch line 14 and a second branch line 15. The first branch line 14 is provided with a temperature-sensitive valve 23.

[0023] The temperature-sensing valve 23 contains a temperature-sensing member that expands and contracts in response to the ambient temperature. The temperature-sensing valve 23 is normally closed, but is configured to open when the temperatures in the air discharge line 13 and the first branch line 14 drop below a preset temperature a.

[0024] An air supply line 16 is connected to the inlet header 2, and high-pressure air is supplied to the inlet header 2 through this air supply line 16. A single air valve 24 is provided between the air supply line 16 and the second branch line 15. The air valve 24 is configured with an electromagnetic valve, and opens and closes the air supply line 16 and the second branch line 15 simultaneously.

[0025] The air valve 24 receives a temperature signal from the above-mentioned temperature sensor 28. The air valve 24 is normally closed, but when the temperature inside the outlet header 3 drops and reaches a preset temperature b, the air valve 24 opens and simultaneously opens the air supply line 16 and the second branch line 15. The temperature b, which is the criterion for the air valve 24 to open, is set to a value smaller than the temperature a, which is the criterion for the above-mentioned temperature-sensitive valve 23 to open.

[0026] (Explanation of heater 1 operation) Next, the operation of the heater 1 will be described. When the heater 1 is operated, the steam valve 21 is opened and steam is supplied to the inlet header 2 through the steam supply line 11. The steam supplied to the inlet header 2 flows into each steam pipe 6 and exchanges heat with the outside air flowing between each steam pipe 6, warming the outside air. Each steam pipe 6 is configured as a thin tube, allowing efficient heat exchange with the outside air.

[0027] The steam in the steam pipe 6 condenses due to heat exchange with the outside air, producing drainage. The drainage falls along the steam pipe 6 and accumulates in the outlet header 3. The drainage in the outlet header 3 flows into the steam trap 22 through the drain discharge line 12, and is automatically discharged to the outside when the valve of the steam trap 22 opens.

[0028] Here, since each steam pipe 6 is configured as a thin tube, the drain does not fall due to the surface tension of the drain inside the steam pipe 6, and may become clogged with the drain by staying inside the steam pipe 6. Drain 60 shown in Fig. 1 is an example of such a clogged drain.

[0029] If drain clogging occurs in the steam pipe 6, the amount of high-temperature drain and steam flowing into the outlet header 3 decreases, and the temperature in the outlet header 3 gradually decreases over time.

[0030] Then, first, when the temperature inside the outlet header 3 reaches temperature a, the temperature sensing valve 23 opens, and the steam and air inside the outlet header 3 are discharged to the outside through the air discharge line 13. At this time, the drain 60 falls due to the influence of the discharge flow of steam and air, which may clear the drain blockage inside the steam pipe 6. Note that opening the temperature sensing valve 23 can also clear air binding inside the steam pipe 6.

[0031] However, even if the temperature sensing valve 23 opens, the clogged drain in the steam pipe 6 may not be cleared. In this case, the temperature in the outlet header 3 continues to drop. The temperature in the outlet header 3 is detected by the temperature sensor 28, and this temperature signal is input to the air valve 24, which detects the temperature drop. Then, when the temperature in the outlet header 3 reaches temperature b, the air valve 24 opens, and simultaneously opens the air supply line 16 and the second branch line 15.

[0032] By opening the air valve 24, high-pressure air is supplied to the inlet header 2 through the air supply line 16, and the inlet header 2 becomes higher pressure than the outlet header 3, creating a pressure difference. The high-pressure air then flows from the inlet header 2 into each steam pipe 6, pressurizing the clogged drain 60 and encouraging and forcing the drain 60 to fall. As a result, the drain 60 falls into the outlet header 3, reliably clearing the clogged drain.

[0033] The air supplied through the air supply line 16 flows from the outlet header 3 into the air discharge line 13 and is discharged to the outside through the second branch line 15. At this time, the temperature-sensitive valve 23 remains open, so the air is also discharged from the first branch line 14 at the same time.

[0034] When the drain blockage in the steam pipe 6 is cleared, the amount of high-temperature drain and steam flowing into the outlet header 3 increases, and the temperature in the outlet header 3 gradually rises over time. Then, when the temperature in the outlet header 3 reaches temperature b, the air valve 24 closes, and the air supply line 16 and the second branch line 15 are closed simultaneously. In addition, when the temperature in the outlet header 3 rises further and reaches temperature a, the temperature-sensitive valve 23 closes, and the first branch line 14 is closed.

[0035] In this embodiment, the air supply line 16 and the second branch line 15 are simultaneously opened and closed by a single air valve 24, so that the supply and discharge of air can be reliably controlled with a simple configuration.

[0036] [Other embodiments] In the above-described embodiment, the heater 1 is given as an example of a heat exchange device having a drain discharge mechanism according to the present application, but the heat exchange device having a drain discharge mechanism according to the present application can be applied to other devices as long as the heat exchange device has a mechanism for discharging drain generated from a heating fluid such as steam.

[0037] In the above embodiment, air is used as an example of the discharge fluid, but other fluids, such as nitrogen, can also be used. Furthermore, in the above embodiment, a plurality of steam pipes 6 (heating pipes) arranged vertically are shown, but this is not limited to this. As long as the configuration allows drainage to fall, a plurality of heating pipes arranged in an oblique direction, for example, may be used.

[0038] Furthermore, in the above embodiment, steam is exemplified as the heating fluid, but other fluids, such as hot water, may be used as long as drain is generated by heat exchange with the outside air. Also, in the above embodiment, the inlet header 2 and the outlet header 3 to which the steam pipes 6 communicate are given as the inlet and outlet portions, but other shapes and structures may be adopted.

[0039] In addition, in the above-described embodiment, the steam trap 22 is exemplified as the drain discharge means, but other means can be used as long as they have a mechanism for discharging, to the outside, the drain that is generated from the heating fluid and falls along the heating tube.

[0040] In the above embodiment, the air valve 23 that simultaneously opens and closes the air supply line 16 and the second branch line 15 is exemplified as the discharge auxiliary means, but the present invention is not limited to this. For example, separate valves can be provided for the air supply line 16 and the second branch line 15. Furthermore, although the air valve 23 constituted by a solenoid valve is exemplified as the discharge auxiliary means, a valve other than a solenoid valve can also be used.

[0041] In addition, in the above-described embodiment, the temperature in the outlet header 3 was used as an example of a fluctuating state, but if it fluctuates depending on the falling condition of the drain in the drain pipe, for example, the sound (vibration) of steam passing through the drain pipe may be detected as the fluctuating state of the drain pipe. [Explanation of symbols]

[0042] 1: Heater 2: Inlet header 3: Outlet header 6: Steam pipe 22: Steam trap 23: Air valve 28: Temperature sensor

Claims

1. an inlet portion through which the heating fluid flows; an outlet portion through which the heating fluid flows out; a plurality of heating tubes communicating with the inlet portion and the outlet portion, through which the heating fluid flows from the inlet portion to the outlet portion; a discharge fluid supply line connected to the inlet portion and capable of opening and closing to supply a discharge fluid; a fluid discharge line connected to the outlet portion and discharging the heating fluid or the discharge fluid; a branch discharge line that branches off from the fluid discharge line and that can be opened and closed; a drain discharge means for discharging drain generated from the heating fluid and falling along the heating tube to the outside; a detection means for detecting a fluctuation state which fluctuates according to a falling state of the drain in the heating pipe; a discharge auxiliary means for opening the discharge fluid supply line to introduce the discharge fluid into the heating tube from the inlet part based on the fluctuation state of the heating tube detected by the detection means, and promoting the fall of drain, and at the same time opening the branch discharge line to discharge the discharge fluid; A heat exchange device having a drain discharge mechanism comprising:

2. In the heat exchange device having the drain discharge mechanism according to claim 1, The detection means detects the temperature of the outlet portion as the fluctuation state. A heat exchange device having a drain discharge mechanism characterized in that:

3. In the heat exchange device having the drain discharge mechanism according to claim 1 or 2, The exhaust assist means introduces air or nitrogen as an exhaust fluid. A heat exchange device having a drain discharge mechanism characterized in that:

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