JP2004077054A - Closed type warm/cold water circulation facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the corrosion of a closed type warm/cold water circulation facility caused by oxygen in replenishing water. <P>SOLUTION: The warm/cool water heated or cooled by a heat source machine 51 flows in a circulation pump 52, a circulation advance pipe 53, a radiator 54 and a circulation returning pipe 55 in this order and is returned to the heat source machine 51. Heating or cooling is carried out by the radiator 54. An expansion tank 57 is connected to the circulation returning pipe 55 through a standing branch pipe 56 and water is stored on the midway in this expansion tank 57. Water level of this water is vertically moved corresponding to the expansion or shrinkage of the water in a circulation passage. An air-shielding floating body 58 is floated on a water surface such that atmosphere in the expansion tank 57 is not contacted with the water. Water deoxidized by a deoxidation device 60 is fed to the expansion tank 57 through a pipe 62. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a closed-type hot / cold water circulating system in which water is circulated between a heat source device and a radiator to perform heating or cooling, and particularly to a closed-type hot / cold water circulating system improved to prevent corrosion of a circulation system. It relates to cold water circulation equipment.
[0002]
[Prior art]
In a closed type hot / cold water circulation system in which water is circulated between a heat source device and a radiator to perform heating or cooling, water is heated or cooled in the heat source device and hot or cold water (hereinafter collectively referred to as The hot and cold water is led to a radiator to radiate heat. As the closed type hot / cold water circulation equipment, there are a closed type in which the circulation system is not open to the atmosphere and an open type in which the circulation path is open to the atmosphere. In the former closed-type hot / cold water circulation system, an expansion tank is provided in the middle of the circulation path to absorb the volume expansion or contraction of water.
[0003]
If oxygen is contained in the circulating water, the corrosion of the equipment and piping will easily progress, but in the case of a closed type, the circulating water does not come into contact with the atmosphere, so the oxygen in the atmosphere does not dissolve into the water and the equipment and piping But hard to corrode.
[0004]
In this closed type hot / cold water circulation system, a deoxygenation device may be provided in the middle of a circulation system in order to reliably prevent corrosion.
[0005]
[Problems to be solved by the invention]
Even in the closed type hot / cold water circulating equipment, the amount of circulating water decreases, so it is necessary to supply make-up water to the circulation system to compensate for this. Since oxygen is contained in the makeup water, especially when a large amount of makeup water is supplied, the oxygen concentration in the circulating water becomes high, and there is a possibility that corrosion occurs in equipment and piping.
[0006]
An object of the present invention is to prevent corrosion of a closed type hot / cold water circulation system caused by oxygen in such makeup water.
[0007]
[Means for Solving the Problems]
The closed hot / cold water circulation system of the present invention is a closed hot / cold water circulation system having a water circulation system, a heat source device, a radiator, and an expansion tank provided in the middle of the water circulation system. It is characterized by comprising a deoxidizing means, and a means for supplying makeup water deoxidized by the deoxidizing means to the expansion tank.
[0008]
In the closed type hot / cold water circulation system of the present invention, since the makeup water is supplied to the circulation system after being deoxygenated, the makeup water is prevented from bringing oxygen into the circulation water, and the circulation caused by the oxygen is prevented. Corrosion of the system is prevented.
[0009]
In the present invention, it is preferable to provide a means for introducing an inert gas into the expansion tank. In the case of such a configuration, the atmosphere above the water surface in the expansion tank is set as an inert gas atmosphere, so that the incorporation of oxygen in the expansion tank can be prevented. This makes it possible to feed water having a very low oxygen concentration from the expansion tank to the circulation path.
[0010]
In the present invention, the deoxygenating means is an inert gas introducing means, an inert gas replacing means for contacting make-up water with an inert gas to replace oxygen in the make-up water with an inert gas, and a gas after contacting the make-up water. It may be a deoxidizing means provided with an exhaust gas means for exhausting gas, and a means for introducing gas exhausted from the exhaust gas means of the deoxidizing means to the expansion tank. With this configuration, the inert gas used in the deoxidizing means is used as the gas for purging the atmosphere in the expansion tank, so that the cost of the inert gas is reduced.
[0011]
In the present invention, a gas shielding means for covering the water surface in the expansion tank may be provided. This can prevent oxygen from being dissolved into water in the expansion tank.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments will be described with reference to the drawings. First, a water deoxidizer suitable for use in the present invention will be described. FIG. 1 is a system diagram of a deaeration unit constituting the deoxygenation device, and FIG. 2 is a system diagram of a deoxygenation device in which a plurality of the deaeration units are connected in series.
[0013]
The degassing unit 10 in FIG. 1 has a rising pipe 1 and a falling pipe 2, and an upper part of the rising pipe 1 and an upper part of the falling pipe 2 are connected by a communication pipe 3. The rising pipe 1 and the falling pipe 2 are erected substantially vertically, and the communication pipe 3 that connects them is provided substantially horizontally.
[0014]
The riser pipe 1 is provided with an ejector 4 for injecting an inert gas (nitrogen gas in FIG. 1). Above the ejector 4, a porous plate 5 as a gas-liquid mixing means is provided. In addition, the communication section 3 is provided with a gas-liquid separator 6 and a gas vent valve 7 as gas discharging means for discharging only gas.
[0015]
Raw water is introduced from a lower part of the riser pipe 1 by a pump or the like, and flows in the riser pipe 1 in an upward flow. In this embodiment, the upward flow rate of the raw water in the rising pipe 1 is adjusted so as to be smaller than the rising rate of the gas in the rising pipe 1. A nitrogen gas is introduced into the ejector 4 from a nitrogen gas source (not shown), and is injected into raw water in the riser pipe 1 by an ejector effect.
[0016]
The raw water into which the nitrogen gas has been injected sufficiently mixes with the injected nitrogen gas when passing through the perforated plate 5. That is, the injected nitrogen gas rises in the rising pipe 1 at a speed higher than the upward flow of the raw water, but the nitrogen gas is prevented from rising by the perforated plate 5, and a nitrogen gas layer is formed below the perforated plate 5. Form. The raw water passes through the nitrogen gas layer, and the raw water and the nitrogen gas are sufficiently contacted as if they pass through the filtration layer of the nitrogen gas layer. Dissolved oxygen moves to the nitrogen gas side, and the raw water is deoxygenated.
[0017]
If the upward flow velocity of the raw water in the rising pipe 1 is higher than the rising rate of the gas, such a nitrogen gas layer is not formed, and sufficient contact efficiency cannot be obtained. It is preferable that the upward flow velocity of the raw water is smaller than the upward velocity of the gas.
[0018]
As the perforated plate 5, for example, a plate in which a plurality of punching plates are stacked so that the hole positions thereof are different in the vertical direction can be used. The hole diameter and thickness of this punching plate, the opening ratio (total area of the opening portion with respect to the total area of the punching plate), the number of stacked layers, the stacking interval, etc. are determined by the scale of the degassing unit, degassing efficiency, water flow efficiency, etc. For example, 1 to 10 punching plates each having a thickness of about 2 to 10 mm and having a hole diameter of about 2 to 5 mm formed at an opening ratio of 20 to 50%, It is preferable to arrange them at intervals of about 20 mm.
[0019]
The specific gravity (for example, 1.1 to 1.1 mm) is set above the perforated plate 5 in the riser pipe 1 and has a diameter larger than the hole diameter of the perforated plate (for example, about 3 to 10 mm) and does not flow out to the degassing valve due to the upward flow of the raw water. 5.0) may be filled to further enhance the gas-liquid contact efficiency. In this case, a perforated plate (not shown) having a hole diameter equal to or smaller than that of the perforated plate 5 near the final end (uppermost portion) of the riser pipe so that the filler does not flow out after the vent valve. ) May be arranged.
[0020]
In addition, the longer the length of the riser pipe 1, particularly the length above the ejector 4, the longer the contact time between the raw water and the nitrogen gas, which is more effective. However, since there is a restriction on the installation space of the apparatus, it is preferable to design the length of the riser pipe 1 so that the length above the ejector 4 is about 0.5 to 1.5 m. Further, it is preferable that the perforated plate 5 as the gas-liquid mixing means is provided about 0.05 to 0.1 m above the ejector 4.
[0021]
The gas-liquid mixed flow which comes into contact with the nitrogen gas while rising in the riser pipe 1 and the dissolved oxygen contained therein moves to the nitrogen gas side and is deoxygenated flows from the upper part of the riser pipe 1 to the communication pipe 3. The gas flows into the communication pipe 3 substantially horizontally, is separated into gas and liquid by the gas-liquid separator 6, and the separated gas is exhausted from the gas release valve 7.
[0022]
The degassing valve 7 is preferably a free-floating lever type valve in which a float is built in and the valve is opened and closed by the float because a complicated control device is not required. Gas is accumulated in the vent valve, and when the accumulated amount increases, the internal float decreases and the valve opens. Also, when the amount of gas decreases, the float rises and the valve closes.
[0023]
Note that such a gas release valve 7 may be provided directly on the communication pipe 3 without providing the gas-liquid separator 6.
[0024]
Most of the gas flowing into the down pipe 2 from the communication pipe 3 has been separated and removed by the gas-liquid separator 6. Are separated. That is, as described above, since the liquid flow velocity in the riser pipe 1 is slower than the rise rate of the gas, when the diameter of the faller pipe 2 is substantially equal to the diameter of the riser pipe 1, Also in the process of flowing down inside 2, the bubbles rise and the gas concentration in the treated water is reduced. Therefore, the longer the down pipe 2 is, the more advantageous in reducing the gas concentration. However, in general, the length of the down pipe 2 is almost equal to the length of the up pipe 1. The riser pipe 2 may be provided with a perforated plate similar to the riser pipe 1 in order to accumulate and associate the bubbles to facilitate the rise.
[0025]
The treated water thus deoxidized is discharged from the lower part of the down pipe 2.
[0026]
The deoxygenating apparatus shown in FIG. 2 connects such a deaeration unit 10 (10A, 10B, 10C, 10D) to the down pipe 2 of the preceding deaeration unit 10 and the rise pipe of the subsequent deaeration unit 10. 1 and 4 are connected in series by connecting tube 11. 2, members having the same functions as the members shown in FIG. 1 are denoted by the same reference numerals.
[0027]
The raw water is introduced into the first deaeration unit 10A via the raw water supply pipe 12 by the pump P, and sequentially flows through the second deaeration unit 10B, the third deaeration unit 10C, and the fourth deaeration unit 10D, so that deoxygenation is performed. Then, the treated water is taken out from the treated water pipe 13 connected to the falling pipe 2 of the fourth deaeration unit 10D.
[0028]
Nitrogen gas from a nitrogen gas source (nitrogen gas cylinder or nitrogen generator) 20 is injected into the ejector 4 of the final stage fourth degassing unit 10D by a pipe. The gas extracted from the degassing valve 7 of the fourth degassing unit 10D is injected from the pipe 15 into the ejector 4 of the third degassing unit 10C. Then, the gas taken out from the degassing valve 7 of the third degassing unit 10C is injected from the pipe 16 into the ejector 4 of the second degassing unit 10B, and is taken out from the gas venting valve 7 of the second degassing unit 10B. Gas is injected into the ejector 4 of the first deaeration unit 10A from the pipe 17, and gas extracted from the degassing valve 7 of the first deaeration unit 10A is exhausted from the degassing valve 7 to the outside of the deoxygenating device.
[0029]
With this deoxidizer, the dissolved oxygen in the raw water can be removed to an extremely low concentration by the treatment with the deaeration units 10A to 10D. In addition, nitrogen gas is injected only into the fourth deaeration unit 10D, and gas exhausted from the subsequent deaeration units 10B to 10D is injected into the preceding deaeration units 10A to 10C, respectively. By increasing the purity of nitrogen gas to be injected into each unit, the amount of nitrogen gas used can be reduced and dissolved oxygen in raw water can be efficiently removed.
[0030]
The pipes 15 to 17 may be provided with a gas pump 30 having the same flow rate as the nitrogen gas source, and forcibly injecting nitrogen gas to stabilize the nitrogen gas injection amount. By doing so, the nitrogen gas can be efficiently supplied to the water.
[0031]
If a check valve is provided just before the ejectors of the pipes 15 to 17 and the gas pump 30 is controlled so as to be linked with the start / stop of the raw water pump, the pipes 15 to 17 are always filled with an inert gas. In this state, even if the deoxidizing device is frequently started and stopped, good deoxygenated water can be produced, which is preferable.
[0032]
FIG. 2 shows an example in which four deaeration units of FIG. 1 are connected in series. However, two, three, or five or more deaeration units may be connected. Further, FIGS. 1 and 2 show the case where nitrogen gas is used as the inert gas. However, in the present invention, the inert gas is not limited to nitrogen gas, and argon or another inert gas can also be used. . However, nitrogen gas is preferable from the viewpoint of cost.
[0033]
FIG. 3 is a system diagram of a deoxidizer in which deaeration units 10E and 10F are connected in series in two stages. In the degassing unit 10E, an ejector 4 is also provided in the falling pipe 2, and nitrogen gas is introduced into the ejector 4 of the falling pipe 2. Instead, the ejector 4 of the rising pipe 1 of the deaeration unit 10F is omitted. That is, the ejector 4 of the rising pipe 1 of the deaeration unit 10F is moved to the falling pipe 2 of the deaeration unit 10E. When the ejector 4 is disposed above the falling pipe 2, the contact time between an inert gas such as a nitrogen gas and water and water becomes longer, and the deoxidation efficiency can be increased.
[0034]
The dissolved oxygen from the raw water can also be efficiently removed by the deoxidizer of FIG.
[0035]
Conventionally, as a deaerator for removing dissolved gas in a liquid, in particular, a deaerator used for deoxygenation treatment, there are a membrane deaerator and a nitrogen gas deaerator.
[0036]
In the membrane deaerator, a vacuum is applied to one side partitioned by the deaeration membrane to reduce the pressure, water to be treated is introduced to the other side, and only dissolved gas in the water to be treated is passed through the deaeration membrane. It is moved to the vacuum side.
[0037]
In such a conventional membrane deaerator, auxiliary equipment such as a vacuum generator and a condensed water separator is required, and the equipment cost is high. In addition, depending on the properties of the water to be treated, maintenance and management is complicated, for example, membrane contamination or membrane deterioration is severe, and the degassing membrane needs to be replaced frequently.
[0038]
On the other hand, in the deoxygenating apparatus shown in FIGS. 1 to 3, the water to be treated into which the inert gas has been injected rises in the riser pipe and is mixed by the gas-liquid mixing means. Water efficiently contacts the inert gas, and the dissolved gas in the water to be treated moves to the inert gas side. Then, the gas that has moved to the inert gas side is discharged from the gas discharge means in the communicating portion above the rising pipe. The water to be treated further descends through the downcomer pipe through the communication section, and while descending in the downcomer pipe, the gas in the water to be treated ascends the downpipe and is discharged from the gas discharge means in the upper communication section. Therefore, the oxygen concentration in the water to be treated is further reduced.
[0039]
In particular, the deoxygenating apparatus shown in FIGS. 1 to 3 includes n deaeration units (n is an integer of 2 or more), and is processed by a k-th deaeration unit (k is an integer of 1 to (n-1)). The degassing units are connected in series so that water is passed through the (k + 1) th degassing unit, and inert gas from the inert gas generation source is supplied to the inert gas injection means of the last nth degassing unit. In addition to supplying the active gas, the gas extracted from the gas discharging means of the (k + 1) -th degassing unit is supplied to the inert gas injection means of the k-th degassing unit in the preceding stage by only one stage. .
[0040]
With this deoxidizer, since the oxygen is deoxidized in multiple stages, the dissolved oxygen in the water to be treated can be removed to an extremely low concentration. In addition, the inert gas is injected into the degassing unit at the last stage, the gas exhausted from the degassing unit at the subsequent stage is injected into the degassing unit at the previous stage, and the inert gas is injected into the degassing unit at the later stage. By increasing the purity of the gas, the amount of inert gas used can be reduced and the dissolved oxygen in the water to be treated can be efficiently removed.
[0041]
That is, a low-purity inert gas containing a large amount of dissolved oxygen separated from the water to be treated is injected into the first-stage deaeration unit. Since high water to be treated is introduced, sufficient deoxygenation efficiency can be obtained even with such a low-purity inert gas. The concentration of dissolved oxygen in the water to be introduced decreases as the degassing unit goes from the first degassing unit to the subsequent degassing unit, but the purity of the inert gas increases, and the degassing efficiency decreases. In the degassing unit at the final stage, the dissolved oxygen in the water to be treated is degassed to a very low concentration by the high-purity inert gas.
[0042]
In the present invention, a deoxygenating means other than those shown in FIGS. The deoxygenating means only needs to be capable of deoxidizing, and does not need to perform degassing. Further, an inert gas such as a nitrogen gas may remain in the deoxygenated water.
[0043]
FIG. 4 is a system diagram of the closed type hot / cold water circulation equipment of the present invention.
[0044]
The hot or cold water heated or cooled by the heat source unit 51 flows in the order of the circulation pump 52, the circulation outgoing pipe 53, the radiator 54, and the circulation return pipe 55, and returns to the heat source unit 51. Heating or cooling is performed by the radiator 54.
[0045]
An open-to-atmosphere expansion tank 57 is connected to the circulation return pipe via a rising branch pipe 56, and water is stored halfway in the expansion tank 57. The level of this water rises and falls according to the expansion and contraction of the water in the circulation path. In the upper part of the expansion tank 57, an inlet for nitrogen gas (N ₂ ) as an inert gas and a gas outlet are provided.
[0046]
The nitrogen gas (N ₂ ) may be supplied from a nitrogen gas source such as a nitrogen gas generator or a nitrogen gas cylinder, or may be a gas discharged from the degassing valve 7 of the deoxidizer. You may. In the latter case, the cost of nitrogen gas can be reduced. When the exhaust gas from the deoxidizer is introduced into the expansion tank 57 as in the latter case, an inert gas such as a nitrogen gas is continuously or intermittently introduced into the expansion tank 57 even when makeup water is not supplied to the expansion tank 57. Preferably, the atmosphere in the expansion tank 57 is purged. For this purpose, for example, the nitrogen gas generator of the deoxidizer is operated even when the makeup water is not supplied. This nitrogen gas generator may be operated at all times, but if it is operated intermittently, the nitrogen usage can be further reduced.
[0047]
In this embodiment, an air-insulating floating body 58 as air-insulating means is floating on the water surface so that the gas above the water surface in the expansion tank 57 does not come into contact with water. The air-insulating floating body 58 is preferably a ball made of a foamed synthetic resin. Since the air-blocking floating body 58 is floating on the water surface, even if a small amount of oxygen is contained in the gas above the water surface, the oxygen is prevented from being dissolved in the water in the expansion tank 57.
[0048]
A make-up water pipe 62 is connected to a lower portion of the expansion tank 57 so as to supply make-up water into the expansion tank 57. For example, water from an elevated water tank is preferably deoxygenated to the makeup water pipe 62 by a deoxygenation device 60 having the configuration shown in FIG. 1, 2, or 3, and a valve 61 (which may be a pump) is provided. Supplied via As described above, since the deoxygenated water is supplied to the circulation system as makeup water via the expansion tank 57, oxygen is not brought into the circulation water by makeup water, and the dissolved oxygen concentration in the circulation water is always extremely low. Will be kept. As a result, corrosion of the circulation path is reliably prevented.
[0049]
【The invention's effect】
As described above, according to the present invention, corrosion of the closed-type hot / cold water circulation equipment caused by oxygen in makeup water is prevented.
[Brief description of the drawings]
FIG. 1 is a system diagram showing a deaeration unit used in a closed type hot / cold water circulation system of the present invention.
FIG. 2 is a system diagram of a deaerator used in the closed type hot / cold water circulation system of the present invention.
FIG. 3 is a system diagram of a deaerator used in the closed type hot / cold water circulation equipment of the present invention.
FIG. 4 is a system diagram of the closed type hot / cold water circulation equipment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rise pipe 2 Fall pipe 3 Communication pipe 4 Ejector 5 Perforated plate 6 Gas-liquid separator 7 Gas release valve 8 Pressure reducing valve 10, 10A, 10B, 10C, 10D, 10E, 10F Deaeration unit 20 Nitrogen gas source 51 Heat source Machine 54 radiator 57 expansion tank 58 air-insulated floating body 60 deoxidizer

Claims (4)

In a closed-circuit type hot / cold water circulation system having a water circulation system and a heat source device, a radiator and an expansion tank provided in the middle of the circulation system,
Means for deoxidizing make-up water;
Means for supplying makeup water deoxygenated by the deoxygenation means to the expansion tank. 2. A closed type hot / cold water circulation system according to claim 1, further comprising means for introducing an inert gas into said expansion tank. 2. The method according to claim 1, wherein the deoxygenating means is an inert gas introducing means.
An inert gas replacing means for contacting the makeup water with an inert gas to replace oxygen in the makeup water with an inert gas;
Deoxygenation means provided with exhaust gas means for exhausting gas after contact with makeup water,
A closed type hot / cold water circulation system comprising: means for introducing gas exhausted from an exhaust gas means of the deoxidizing means to the expansion tank. The closed type hot / cold water circulation equipment according to any one of claims 1 to 3, further comprising an air shielding means for covering a water surface in the expansion tank.

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