Gas detection device

Abstract

To detect gas to be mixed into a flow channel of a cooling liquid in an early stage.SOLUTION: A gas detection device comprises: a branch part connected to a flow channel of a cooling liquid so as to guide gas flowing together with the cooling liquid to a branch flow passage branched from the flow channel; a gas mixing part including an inflow port where the gas to be guided to the branch flow passage flows in, an outer air intake port arranged at a position lower than the inflow port, and a gas outlet port arranged at a position upper than the inflow port, thereby allowing the mixture gas of the gas to flow in from the inflow port with the outer air to be taken in from the intake port to be sent from the outlet port; and a detection part for detecting a predetermined detection target gas from the mixture gas to be sent from the gas mixture part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gas sensing device. [Background technology]

[0002] Generally, equipment such as hydrogen compressors and generators are liquid-cooled, cooled by a coolant such as water circulating in a closed cycle. A heat exchanger is provided in the closed cycle, and the coolant that has been warmed by cooling the equipment is cooled by the heat exchanger and is used again to cool the equipment.

[0003] When a cooling liquid is cooled in a heat exchanger, a gas such as cooled hydrogen gas may be used. That is, in the heat exchanger, a warmed cooling liquid and a cooled gas exchange heat through a solid wall such as a metal wall, and the cooling liquid is cooled and the gas is warmed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 4-334948 Summary of the Invention [Problem to be solved by the invention]

[0005] In the heat exchanger described above, the coolant and the gas such as hydrogen gas are separated by a solid wall, so that the gas does not usually get mixed into the coolant flow path. However, if the solid wall deteriorates due to, for example, corrosion of the metal that forms the solid wall, the gas may leak into the coolant flow path, and for example, flammable hydrogen gas may be diffused to unintended locations.

[0006] In addition, when the equipment to be cooled by the coolant uses gas such as hydrogen gas, gas may leak into the coolant flow path not only in the heat exchanger but also in the cooling object. In this way, when the gas leaking into the coolant flow path is a flammable gas such as hydrogen gas or a toxic gas that is harmful to the human body, it is preferable to detect the gas leakage early.

[0007] The present disclosure has been made in consideration of the above points, and has an object to provide a gas detection device that can detect gas entering a coolant flow path at an early stage. [Means for solving the problem]

[0008] According to one aspect of the present disclosure, a gas detection device has a branching section connected to a cooling liquid flow path and guiding gas flowing together with the cooling liquid to a branching flow path branching off from the flow path, an inlet through which gas guided to the branching flow path flows, an outside air intake located below the inlet, and a gas outlet located above the inlet, a gas mixing section that outputs from the outlet a mixed gas of the gas flowing in from the inlet and the outside air taken in from the intake, and a detection section that detects a predetermined target gas from the mixed gas output from the gas mixing section. Effect of the Invention

[0009] According to the present disclosure, gas entering the coolant flow path can be detected at an early stage. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing a configuration of a gas detection device according to an embodiment. [Diagram 2] FIG. 2 is a diagram illustrating ventilation control by the ventilation control unit. [Diagram 3] FIG. 3 is a diagram showing the configuration of the gas mixer. [Figure 4] FIG. 4 is a diagram showing a specific example of detection performance. [Diagram 5]FIG. 5 is a diagram showing a modified example of the gas detection device according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The embodiment described below is an example, and should not be construed as being limited by this description.

[0012] FIG. 1 is a diagram showing the configuration of a gas detection device 100 according to one embodiment. The gas detection device 100 shown in FIG. 1 is connected to a closed-cycle coolant flow path that circulates through a heat exchanger 200 and a cooling target 300, and detects hydrogen gas that is mixed into the coolant flow path in the heat exchanger 200 or the cooling target 300. The heat exchanger 200 cools the coolant by heat exchange between a gas, such as hydrogen gas, and the coolant. The cooling target 300 is a device, such as a hydrogen compressor or a generator, and is cooled by the coolant. The heat exchanger 200 and the cooling target 300 are connected by piping that serves as the coolant flow path, forming a closed cycle in which the coolant circulates.

[0013] Gas detection device 100 has a branch pipe 110 , a valve 120 , a ventilation control section 130 , a gas mixing section 140 , a gas detector 150 , and a drainage section 160 .

[0014] The branch pipe 110 is connected to the flow path of the coolant and branches the flow path of the coolant. That is, the branch pipe 110 has, for example, a T-shape, and forms a part of the flow path of the coolant flowing from the heat exchanger 200 to the object to be cooled 300, and also forms a branch flow path that guides a part of the coolant flowing through this flow path to the valve 120 above. Therefore, for example, when hydrogen gas is leaking into the flow path of the coolant in the heat exchanger 200, the branch pipe 110 guides a part of the hydrogen gas mixed into the flow path to the valve 120 together with the coolant.

[0015] The gas mixed into the coolant flow path is a water-insoluble gas such as hydrogen gas, and flows in the form of bubbles together with the coolant in the coolant flow path. Since the density of this gas is smaller than the density of the coolant, the gas flows into the branch flow path going upward and is guided to valve 120. Also, the coolant flows into the branch flow path going upward and is guided to valve 120 due to the pressure of the liquid flow in the flow path.

[0016] Valve 120 regulates the flow of the cooling liquid and hydrogen gas guided by branch pipe 110 into ventilation control unit 130. That is, valve 120 can be opened and closed by moving a lever, and in the open state, valve 120 allows the cooling liquid and hydrogen gas guided from branch pipe 110 to flow into ventilation control unit 130, and in the closed state, valve 120 prevents the cooling liquid and hydrogen gas guided from branch pipe 110 from flowing into ventilation control unit 130.

[0017] The ventilation control unit 130 collects hydrogen gas flowing in from the open valve 120 and controls the delivery to the gas mixer 140. Specifically, the ventilation control unit 130 has a float that floats on the cooling liquid stored in an internal storage tank, and controls the opening and closing of the hydrogen gas outlet by the rise and fall of the float according to the height of the cooling liquid level.

[0018] FIG. 2 is a diagram illustrating ventilation control by the ventilation control unit 130. As shown in FIG. As shown in FIG. 2(a), a float 132 that floats on the cooling liquid is disposed in the storage tank 131 of the ventilation control unit 130. The cooling liquid and hydrogen gas can flow in from the inlet 131a of the storage tank 131, but when hydrogen gas is not mixed in the flow path of the cooling liquid, the storage tank 131 is filled with only the cooling liquid. At this time, since the liquid level of the cooling liquid is high in the storage tank 131, the float 132 rises and pushes up the lever 133. A valve body 134 is connected to the upper surface of the lever 133, and when the lever 133 is pushed up, the outlet 131b of the storage tank 131 is closed by the valve body 134. Therefore, when hydrogen gas is not mixed in the flow path of the cooling liquid, the outlet 131b is closed and the cooling liquid does not flow out of the storage tank 131.

[0019] Here, if hydrogen gas is mixed in the flow path of the cooling liquid, the hydrogen gas flows into the storage tank 131, and as the hydrogen gas is collected in the storage tank 131, the liquid level of the cooling liquid gradually drops. Then, when the liquid level of the cooling liquid drops, the float 132 descends, and the lever 133 and the valve body 134 also descend, as shown in FIG. 2(b). As a result, the valve body 134 that had been closing the outlet 131b moves downward, and the outlet 131b is opened. Therefore, when the amount of hydrogen gas remaining in the storage tank 131 increases, the hydrogen gas flows out from the outlet 131b.

[0020] In this manner, when hydrogen gas accumulates in the storage tank 131, the ventilation control unit 130 opens the outlet 131b to send the hydrogen gas therein to the gas mixer 140.

[0021] The gas mixer 140 mixes the hydrogen gas sent from the ventilation control unit 130 with air, and sends the resulting mixed gas to the gas detector 150. That is, the gas mixer 140 has an inlet for introducing hydrogen gas between an intake port for taking in outside air and an outlet port for sending gas to the gas detector 150, and mixes the hydrogen gas flowing in from the inlet with the air moving from the intake port to the outlet port, and sends the mixed gas from the outlet port. The gas mixer 140 also drains moisture that flows in from the ventilation control unit 130 together with the hydrogen gas via the drainage unit 160.

[0022] FIG. 3 is a diagram showing the configuration of the gas mixer 140. As shown in FIG. 3, the gas mixer 140 has a tank-like structure with multiple inlets and outlets. That is, one side of the tank 141 capable of storing gas therein is provided with an inlet 142 through which hydrogen gas flows in, and the other side of the tank 141 is provided with an inlet 143 through which external air (outside air) is taken in. The upper surface of the tank 141 is provided with an outlet 144 through which a mixture of hydrogen gas and air is sent to the gas detector 150, and the lower surface of the tank 141 is provided with a drain port 145 through which moisture that flows into the tank 141 together with the hydrogen gas is drained.

[0023] Since the inlet 142 opens into the tank 141 at a position higher than the intake 143 that takes in outside air and lower than the outlet 144 that outputs the mixed gas, the hydrogen gas flowing in from the inlet 142 is mixed with the air moving from the intake 143 to the outlet 144. Therefore, the outlet 144 can reliably output the mixed gas of hydrogen gas and air to the gas detector 150.

[0024] Furthermore, moisture that flows in from inlet 142 together with hydrogen gas accumulates at the bottom of tank 141 and is drained from drain outlet 145 via drain unit 160. This prevents moisture that accumulates at the bottom from reaching outside air intake 143 and flowing back from intake 143, and prevents the inflow of air from being impeded.

[0025] In addition, the inlet 142 and the intake 143 may be provided on the same side of the tank 141.

[0026] The gas detector 150 sucks the mixed gas from the gas mixer 140 and detects that the mixed gas contains a predetermined gas to be detected. Specifically, the gas detector 150 may be a general-purpose gas detector equipped with, for example, a hot wire semiconductor sensor or a catalytic combustion sensor, and detects the target gas, for example, hydrogen gas. The gas detector 150 may use a combustion reaction using air (oxygen) when detecting the target gas, and since the target gas, for example, hydrogen gas, is mixed with air in the gas mixer 140, it is possible to reliably detect hydrogen gas. When the gas detector 150 detects the target gas, it outputs, for example, an alarm sound or displays a warning.

[0027] The drainage section 160 discharges the wastewater from the drain port 145 of the gas mixing section 140, for example, to an external drain. The drainage section 160 passes the wastewater from above through an S-shaped tube and discharges it to a drain below. As a result, some of the wastewater remains in the curved part of the S-shaped tube of the drainage section 160, preventing the passage of gas. As a result, gas is prevented from flowing out from the gas mixing section 140 through the drainage section 160, and the reliability of gas detection can be ensured.

[0028] In this way, gas detection device 100 collects hydrogen gas that enters the coolant flow path, mixes it with air, and detects hydrogen gas from the resulting mixed gas using gas detector 150. This makes it possible to quickly detect hydrogen gas that enters the coolant flow path.

[0029] FIG. 4 is a diagram showing a specific example of the amount of hydrogen gas leaking into the coolant flow path and the detection time until gas detection device 100 detects hydrogen gas. As shown by the straight line approximation of the relationship between leakage amount and detection time plotted in Figure 4, the detection time tends to be longer as the amount of hydrogen gas leaking into the coolant flow path decreases. For example, when the leakage amount of hydrogen gas is about 0.08 NL (normal liters) per minute, hydrogen gas can be detected in about 30 seconds to 1 minute, and when the leakage amount of hydrogen gas is about 0.04 NL per minute, hydrogen gas can be detected in about 1 minute 30 seconds to 2 minutes.

[0030] As described above, according to this embodiment, hydrogen gas that has entered the coolant flow path is collected and introduced into the inlet located between the tank's outside air intake and gas outlet, whereby the hydrogen gas and air are mixed, and the resulting mixed gas is sent out from the outlet to the gas detector. This makes it possible to detect gas entering the coolant flow path at an early stage.

[0031] In the above embodiment, the ventilation control unit 130 collects hydrogen gas and controls its delivery to the gas mixing unit 140, but the hydrogen gas may also flow directly into the gas mixing unit 140 from the cooling liquid flow path.

[0032] Fig. 5 is a diagram showing a modified example of gas detection device 100 according to one embodiment. In Fig. 5, the same components as in Fig. 1 are denoted by the same reference numerals. 5, gas detection device 100 does not have ventilation control unit 130, and when valve 120 is in an open state, hydrogen gas flows from the coolant flow path to inlet 142 of gas mixing unit 140. At this time, moisture that flows in from inlet 142 together with hydrogen gas accumulates at the bottom of tank 141 and is drained from drain outlet 145 via drain unit 160.

[0033] In this way, gas detection device 100 according to the present embodiment is capable of detecting gas entering the flow path of the cooling liquid with a simple configuration.

[0034] The diameter of the branch pipe 110 may be larger than the diameter of the surrounding piping that forms the flow path of the coolant. That is, the flow rate of the coolant in the branch pipe 110 may be reduced by making the diameter of the portion of the branch pipe 110 that forms the flow path connecting the heat exchanger 200 and the object to be cooled 300 larger than the diameter of the surrounding piping. By reducing the flow rate of the coolant in the branch pipe 110, it is possible to guide more of the hydrogen gas that flows together with the coolant to the branched flow paths, and it is possible to further shorten the time until the hydrogen gas is detected.

[0035] Furthermore, in the above embodiment, the gas that gets mixed into the coolant flow path and is the target of detection by gas detector 150 is described as hydrogen gas, but gas detection device 100 can also be used to detect gases other than hydrogen gas. [Explanation of symbols]

[0036] 100 Gas detection device 110 Branch pipe 120 Valve 130 Ventilation control section 140 Gas Mixing Section 141 Tank 142 Inlet 143 Intake 144 Outlet 145 Drain 150 Gas Detector 160 Drainage section

Claims

1. a branching portion connected to a flow path of the cooling liquid and configured to guide a gas flowing together with the cooling liquid to a branching flow path branching from the flow path; a gas mixing section having an inlet through which gas guided to the branch flow path flows, an outside air intake provided below the inlet, and a gas outlet provided above the inlet, and which outputs a mixed gas of the gas flowing in from the inlet and the outside air taken in from the intake from the gas mixer; a detection unit that detects a predetermined detection target gas from the mixed gas sent out from the gas mixing unit; A gas detection device having the following:

2. a ventilation control unit that collects the gas guided to the branch flow path and controls the delivery of the collected gas to the gas mixing unit; The gas sensing device of claim 1 further comprising:

3. The gas mixing section includes: A drain port is provided for draining moisture that flows in together with the gas from the inlet.

3. The gas detection device according to claim 1 or 2.

4. The detection unit is A gas detector that detects a predetermined target gas by a combustion reaction of the mixed gas is provided.

3. The gas detection device according to claim 1 or 2.

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