Decontamination system with recycling

Abstract

The invention relates to a gas decontamination system (1) for a gas turbine test bench (80) (90), comprising an upstream pipe (10) whose upstream end (11) is connected to the outlet of the test bench (80), a fluid reservoir (30) whose inlet (31) is connected to the downstream end (12) of the upstream pipe (10), and a downstream pipe (60) which is connected to the outlet (32) of the reservoir (30) and which discharges downstream into the atmosphere. The decontamination system (1) includes a device for recycling the liquid (L) from the reservoir (30), which is connected to the reservoir (30) by a first pipe (T1) and a second pipe (T2), and which includes a rainwater recovery device (78) and a purification device (79) for this rainwater and the liquid (L) from the reservoir (30). Figure 1

Description

Title of the invention: Decontamination system with recycling

[0001] The present invention relates to a decontamination system for a gas turbine test bench, for example a turbomachine.

[0002] Such a test bench comprises, from upstream to downstream (in the normal direction of airflow), an intake chamber, a turbomachine test chamber, and an exhaust stack. Air enters the test chamber through the intake chamber. The test chamber includes a turbomachine mounted on a thrust balance. In this test chamber, downstream of the turbomachine being tested, there is an exhaust duct comprising a tube that receives the exhaust gases escaping from the turbomachine during its test. The exhaust gases exit this tube and ascend into the exhaust stack.

[0003] Due to combustion in the turbomachine, the gases exiting the exhaust duct contain carbon dioxide. Furthermore, in certain configurations known as confined test benches, fine particles, sand, and corrosive gases (e.g., sulfur gas) are injected into the turbomachine to test its resistance under conditions similar to actual flight conditions in certain climates. These gases and particles are present in the stream ejected from the exhaust duct and subsequently flowing through the exhaust stack.

[0004] These gases and particles are pollutants, and the aim is to reduce their release into the atmosphere. To this end, a gas treatment device for these gas streams is placed in the exhaust stack. This treatment device includes filters with materials capable of adsorbing the gas, for example, carbon dioxide filters, and it includes electrostatic precipitators capable of capturing polluting particles.

[0005] However, existing treatment devices are not sufficiently effective in removing pollutants from the gas stream exiting the gas turbine test bench. Consequently, there are emissions of pollutants, especially particulate matter and corrosive gases, which are too high in relation to environmental protection standards. To solve this problem, a liquid-filled tank was placed downstream of the treatment device, with the tank opening to the atmosphere. The gas from the test bench flows through the tank in contact with this liquid, which promotes the dissolution of polluting gases, such as corrosive gases, in the liquid.

[0006] Thus, a gas decontamination system is known for a gas turbine test bench, this system being designed to extract pollutants present in the gas stream displaced by the operating turbine, the decontamination system comprising an upstream pipe whose upstream end is intended to be fluidly connected to the outlet port of the test bench, a fluid reservoir whose inlet port is located above the liquid contained in the reservoir and is fluidly connected to the downstream end of the upstream pipe, and a downstream pipe which is fluidly connected to the outlet port of the reservoir and which opens downstream into the atmosphere.

[0007] For ecological reasons, the aim is to reuse the liquid present in the tank by removing as many pollutants as possible. Description of the invention

[0008] The present invention aims to provide a pollution control system for a gas turbine test bench in which the treatment of pollutants present in the gas flow displaced by this operating gas turbine is carried out with optimal efficiency, and in the most environmentally friendly way possible.

[0009] This goal is achieved thanks to the fact that the decontamination system includes a device for recycling the liquid L contained in the tank which is fluidly connected upstream to the tank by a first pipe and fluidly connected downstream to the tank by a second pipe, and which includes a rainwater recovery device and a device for purifying this rainwater and the liquid L from the tank.

[0010] These provisions help to avoid using external water by reusing the purified liquid L instead. Furthermore, rainwater is used, which also helps to avoid using external water that is not freely available. In addition, some of the water in the tank evaporates due to contact with the hot gases circulating on its surface. This evaporated water is thus replenished.

[0011] For example, the purification device comprises, from upstream to downstream in fluidic communication, a first module connected upstream to the first pipe and to the rainwater recovery device and which includes a separator to separate the liquid circulating in the module from the waste present in the liquid, a second module which includes a coagulant injector in the liquid to coagulate the particles present in the liquid, a third module which includes a filter to retain the impurities present in the liquid, a fourth module which includes an ozone injector in the liquid to eliminate the impurities present in the liquid, a fifth module which includes a disinfectant injector in the liquid to disinfect the liquid and which is connected downstream to the second pipe.

[0012] For example, the separator is a plurality of sieves with meshes of decreasing size from upstream to downstream.

[0013] For example, the coagulant is an inorganic coagulant.

[0014] For example, the filter is a bed of adsorbent material.

[0015] For example, the decontamination system includes an oxygen supplier which is located in the tank and is intended to be located below the surface S of the liquid L contained in the tank, and a reagent supplier capable of reacting with oxygen and corrosive molecules present in the gas.

[0016] For example, the fifth module further includes a reagent injector.

[0017] For example, the decontamination system includes a gas cleaning device which is located in the upstream pipeline.

[0018] The invention also relates to a gas decontamination process for a gas turbine test bench which is intended to extract pollutants present in the gas stream which is moved by the operating turbine.

[0019] According to the invention, the method comprises the following steps (a) A fluid reservoir, an upstream pipe and a downstream pipe are provided, and the outlet port of the test bench and the inlet port of the reservoir are fluidly connected with the upstream pipe, the inlet port being located above the liquid L contained in the reservoir, the outlet port of the reservoir and the atmosphere are fluidly connected with the downstream pipe, such that the polluted gas from the test bench flows to the atmosphere through the upstream pipe, through the reservoir above the liquid and through the downstream pipe. (e) The unpolluted gas coming from the inlet pipe is evacuated through the outlet pipe. (f) The liquid L contained in the tank is recycled using a recycling device which is fluidly connected upstream to the tank by a first pipe and fluidly connected downstream to the tank by a second pipe, and which includes a rainwater recovery device and a device for purifying the rainwater and the liquid L from the tank.

[0020] For example, the process includes a step (c) in which a reagent is added to the contaminated liquid using a reagent supplier and a step (d) in which oxygen is injected below the surface of the contaminated liquid in the tank using an oxygen supplier in order to create a chemical reaction between the corrosive pollutant present in the gas and the reagent and the oxygen

[0021] The invention will be better understood and its advantages will become more apparent upon reading the following detailed description of embodiments shown by way of non-limiting examples. The description refers to the accompanying drawings in which:

[0022] [Fig. 1] The [Fig. 1] is a perspective view of a gas turbine test bench with a pollution control system according to the invention.

[0023] [Fig.2] Fig.2 is a longitudinal cross-sectional view of the pollution control system of the [Fig.l].

[0024] [Fig.3] The [Fig.3] is a longitudinal cross-sectional view of the recycling device of the pollution control system of the [Fig.1]. Detailed description of the invention

[0025] In the description below, the terms "upstream" and "downstream" are defined with respect to the normal direction of gas and air flow in the test bench, the gas turbine, and the exhaust duct during normal operation of the invention. "Fluidically connected" means that the connection allows the flow of a fluid (liquid or gas).

[0026] The invention is described below in the case where the gas turbine is a turbomachine, but it applies to any gas turbine. The invention applies to any pollution control system in which polluted gas flows above and in contact with a liquid contained in a reservoir and which is polluted by this flow.

[0027] Fig. 1 represents a test bench 80 of a turbomachine 90 according to the invention. This test bench 80 comprises a building which includes, from upstream to downstream (in the normal direction of airflow during operation of the turbomachine 90, represented by a white arrow F), an intake room 81, a test room 82, and an exhaust stack 83. In the case of a confined test bench, air enters the test room 82 through the intake room 81. The upstream end of the intake room 81 (on the left in the figure) is then closed by a door 815. Sand and / or other abrasive particles are injected into the intake room 81 by a first upstream injector 85 upstream of the turbomachine 90. Optionally, a corrosive gas (for example, containing sulfur) is injected by a second upstream injector 86 into the intake room 81.Test room 82 includes a turbomachine 90 which is mounted on a thrust balance 91 and is intended for testing.

[0028] The gas flow displaced by the turbomachine 90 passes through the exhaust stack 83 and then exits the building. For example, the exhaust stack 83 has a bend and a horizontal section, as illustrated in [Fig. 1]. Optionally, the exhaust stack 83 includes a treatment device 84 comprising filters with materials suitable for adsorbing polluting gas in the gas flow displaced by the turbomachine 90 and / or electrostatic precipitators suitable for absorbing polluting particles. For clarity, the test bench 80 is shown with a dashed line.

[0029] The decontamination system 1 according to the invention is now described. This system is designed to extract pollutants present in the gas stream exiting the exhaust stack 83. These pollutants are carbonaceous particles produced by combustion in the turbomachine, polluting particles introduced into the test bench 80 such as sand, and one or more corrosive gases. The decontamination system 1 is shown in [Fig. 1] and also in [Fig. 2], which represents this system of Decontamination 1 in longitudinal section. In these figures, gas circulation is indicated by white arrows F.

[0030] The decontamination system 1 includes an upstream pipe 10 whose upstream end 11 is fluidically connected to the outlet of the exhaust stack 83. The decontamination system 1 includes a fluid reservoir 30 whose inlet 31 is fluidly connected to the downstream end 12 of said upstream pipe 10. In operation, the inlet 31 is located above the surface S of the liquid L contained in the reservoir 30, the reservoir 30 also containing the gas which flows above this liquid L. The decontamination system 1 includes a downstream pipe 60 which is fluidly connected to the outlet 32 ​​of the reservoir 30 and which opens downstream to the atmosphere. For example, this outlet 32 ​​is located in the upper wall of the reservoir 30.

[0031] Advantageously, the decontamination system 1 further comprises a gas cleaning device 20 located in the upstream pipeline 10. This cleaning device 20 sprays liquid that wets the polluting particles present in the gas flowing in the upstream pipeline 10. Thus, these polluting particles are carried by gravity to the bottom (lower part) of the tank 30 to form a certain quantity of polluted liquid which is added to the liquid contained in the tank 30. For example, the cleaning device 20 comprises one or more liquid spray nozzles 21.

[0032] The gas then enters the tank 30 and flows over the liquid L contained in the tank 30. A standing wave of turbulent flow, called the foam zone, is generated on the surface of the contaminated liquid in contact with the gas. The foam zone creates a high rate of liquid surface renewal. Furthermore, the gas temperature is reduced to its adiabatic saturation temperature, which allows for the treatment of hot gases (up to 1200°C). Thus, corrosive molecules (e.g., sulfur compounds such as SO2) present in the gas are absorbed into the liquid.

[0033] The decontamination system 1 includes a recycling device 70 for the liquid L contained in the tank 30. This recycling device 70 is capable of discharging liquid from the tank 30 via a first pipe TL. The first pipe TL is therefore upstream of the recycling device 70. The recycling device 70 includes a rainwater recovery device 78 and a purification device 79 for this rainwater and the liquid L coming from the tank 30 via the first pipe TL. After purification, the water flows from the recycling device 70 back into the tank 30 via a second pipe T2. The second Pipe T2 is downstream of the recycling device 70. The direction of liquid flow is illustrated in the figures by black arrows G.

[0034] An embodiment of the recycling device 70 is described below, with reference to [Fig. 3]. The recovery device 78 consists of one or more tanks suitable for collecting rainwater. For example, each tank has a capacity greater than 10,000 liters. The purification device 79 comprises, from upstream to downstream, a plurality of modules in fluidic communication in order to purify the liquid flowing through them. Each module includes a container for collecting liquid, and each container is connected to the upstream container and the downstream container by a pipe.

[0035] The purification device 79 comprises a first module 71 fluidically connected upstream to the first pipe T1 and to the rainwater recovery device 78. The first module 71 thus collects the liquid L from the reservoir 30 and the rainwater. The first module 71 includes a separator 715 to separate the liquid circulating in the module 71 from the waste present in the liquid. This waste is, for example, plant debris, soil, or granules. For example, the separator 715 is a plurality of sieves with mesh sizes decreasing from upstream to downstream so as to retain increasingly finer waste.

[0036] The purification device 79 includes a second module 72 which comprises a coagulant injector 725 for coagulating particles present in the liquid. For example, this coagulant is an inorganic coagulant, such as aluminum salts, aluminum polymers, iron salts, or metallic salts. After coagulation, the particles clump together and settle to the bottom of the container through a natural process of decantation. The liquid exiting the second module 72 into the third module 73 is thus free of these particles.

[0037] The purification device 79 includes a third module 73 which comprises a filter 735 for retaining impurities present in the liquid. The impurities are retained by the filter material by adsorption and / or absorption. For example, this filter is a bed of material. For example, this material is sand and activated carbon.

[0038] The purification device 79 includes a fourth module 74 which includes an ozone injector 745 in the liquid to eliminate impurities present in the liquid.

[0039] The purification device 79 includes a fifth module 75 which comprises a disinfectant injector 755 for the liquid in order to destroy bacteria. This disinfectant is, for example, chlorine. The fifth module is connected downstream to the second pipe T2. Advantageously, the fifth module (75) further comprises a reagent injector 756 which is capable of reacting chemically with the corrosive gas contained in the gas circulating in the tank 30 This reagent is that supplied by the reagent supplier 45 (see below).

[0040] The liquid initially present in the tank 30 is, for example, water. Advantageously, this liquid is water charged with a chemical reagent capable of reacting with the corrosive gas, and which in this case may be viscous. This reagent is introduced into this liquid by a reagent supplier 45 before or after the liquid is introduced into the tank 30. The reagent supplier 45 is schematically illustrated by dashed lines in [Fig. 2] within the tank 30. The reagent is intended to react with the molecules of the corrosive gas to form a product that can then be easily extracted from the liquid, for example, because this product is anhydrous.Optionally, in cases where the reagent is capable of reacting with oxygen and corrosive molecules, the contamination system 1 further includes an oxygen supplier 40 located in the reservoir 30 and intended to be situated below the surface S of the liquid L contained in the reservoir 30 as illustrated in [Fig.2]. This oxygen can be supplied in the form of air.

[0041] For example, if the polluted gas entering the upstream pipeline 10 contains the sulfur pollutant SO2, the reagent contains CaCO3 (calcium carbonate). The decontamination system 1 includes an oxygen supplier 40. The CaCO3 particles react with the oxygen supplied by the injector 40 and with the SO2 to form calcium sulfate according to the reaction: 2 CaCO3 + 2 SO2 + O2 → 2 CaSO4 + 2 CO2

[0042] Calcium sulfate (CaSO4) is an anhydrous, solid, ionic mineral chemical compound. It therefore does not mix with water. Thus, it can be collected and drained at the first pipe TL. The liquid subsequently returned to the tank is therefore less contaminated.

[0043] Advantageously, the cleaning device 20 is fluidly connected to a pump 22 which is fluidly connected to the reservoir 30 and which is capable of supplying unpolluted liquid to the cleaning device 20. This connection can be at the level of the second pipe T2.

[0044] Advantageously, the decontamination system 1 includes a grid 50 located in the reservoir 30 downstream of the portion of the reservoir 30 intended to contain the liquid and upstream of the outlet orifice 32. The grid 50 collects any liquid droplets that may be carried along by the gas flow circulating towards the outlet orifice 32. For example, the grid 50 is a vane-type defogging device. As shown in [Fig. 2], the grid 50 is located above the lower portion of the reservoir 30 where the contaminated liquid L is located. The gas flow rises from the inlet orifice 31 and passes through the grid 50.

[0045] Advantageously, the downstream pipe 60 is equipped with a fan 65 that circulates the gases from upstream to downstream. This facilitates the extraction of gases from the reservoir 30. This gas is air, or nearly pure air, since the gas exiting the reservoir through the outlet 32 ​​is decontaminated of gaseous and particulate pollutants.

[0046] The invention also relates to a decontamination method with the decontamination system as described above. In a step (a), a fluid reservoir 30, an upstream pipe 10, and a downstream pipe 60 are provided. The outlet port of the test bench 80 and the inlet port 31 of the reservoir 30 are fluidly connected by means of the upstream pipe 10, the inlet port 31 being located above the liquid L contained in the reservoir 30. The outlet port 32 of the reservoir 30 and the atmosphere are fluidly connected by means of the downstream pipe 60, such that the contaminated gas from the test bench flows in the upstream pipe 10, then into the reservoir 30 above the liquid L, and then into the downstream pipe 60. The reservoir 30 initially contains an uncontaminated liquid L, for example, water.

[0047] Optionally, in a step (b) the pollutant particles present in the polluted gas are moistened (wet) using a cleaning device 20 located in the upstream pipe 10 so as to extract the polluted particles from the polluted gas. These wet particles fall into the tank 30 by gravity.

[0048] The corrosive gas molecules present in the gas are dissolved at the interface between the gas and the liquid L in a flow zone which forms at the interface between this gas and this polluted liquid.

[0049] In a step (e) the unpolluted gas coming from the inlet pipe is evacuated through the outlet pipe 60.

[0050] In a step (f) the liquid L contained in the reservoir 30 is recycled using the recycling device 70 as described above. Steps (f) and (e) occur simultaneously.

[0051] Advantageously, in a step (c), a reagent is added to the contaminated liquid using a reagent supply 45. This mixing of the reagent with the contaminated liquid is carried out by adding the reagent to the tank 30 in step (a) or in step (d) below. For example, the reagent is placed in the liquid that is brought into the tank by the recycling device 70. In a step (d), oxygen is injected (immediately) beneath the surface of the contaminated liquid in the tank 30 using an oxygen supply 40 in order to create a chemical reaction between the corrosive pollutant present in the gas and the reagent and the oxygen.

[0052] Advantageously, in a step (g) before step (e), droplets of liquid present in the gas flowing towards the outlet 32 ​​of the reservoir are recovered by means of a grid 50. This grid 50 is located in the reservoir 30 above the liquid polluted and upstream of the outlet orifice 32. Thus, these droplets fall back into the polluted liquid of the tank 30, which helps to clean the gas before it exits the tank 30.

Claims

1.

2. Demands Gas decontamination system (1) for a gas turbine (90) test bench (80), said system (1) being intended to extract pollutants present in the gas stream which is displaced by said turbomachine (90) in operation, said decontamination system (1) comprising an upstream pipe (10) the upstream end (11) of which is intended to be fluidly connected to the outlet port of said test bench (80), a fluid reservoir (30) the inlet port (31) of which is located above the liquid (L) contained in said reservoir (30) and is fluidly connected to the downstream end (12) of said upstream pipe (10), and a downstream pipe (60) which is fluidly connected to the outlet port (32) of said reservoir (30) and which discharges downstream into the atmosphere,said decontamination system (1) being characterized in that it comprises a recycling device (70) for the liquid (L) contained in said tank (30) which is fluidly connected upstream to said tank (30) by a first pipe (T1) and fluidly connected downstream to said tank (30) by a second pipe (T2), and which comprises a rainwater recovery device (78) and a purification device (79) for said rainwater and said liquid (L) from said tank (30). Decontamination system (1) according to claim 1 wherein said purification device (79) comprises, from upstream to downstream in fluidic communication, a first module (71) connected upstream to said first pipe (T1) and to said rainwater recovery device (78) and which includes a separator (715) for separating the liquid circulating in said module (71) from the waste present in said liquid, a second module (72) which includes a coagulant injector (725) in said liquid for coagulating the particles present in said liquid, a third module (73) which includes a filter (735) for retaining the impurities present in said liquid, a fourth module (74) which includes an ozone injector (745) in said liquid for removing the impurities present in said liquid, a fifth module (75) which includes a disinfectant injector (755) in said liquid for disinfecting said liquid and which is connected downstream to said second pipe (T2).

3. Decontamination system (1) according to claim 2 wherein said separator (715) is a plurality of sieves with mesh sizes decreasing from upstream to downstream.

4. Decontamination system (1) according to claim 2 or 3 wherein said coagulant is an inorganic coagulant.

5. Decontamination system (1) according to any one of claims 2 to 4 wherein said filter (735) is a bed of adsorbent material.

6. Decontamination system (1) according to any one of claims 1 to 6 wherein it comprises an oxygen supplier (40) which is located in said tank (30) and which is intended to be located below the surface (S) of the liquid (L) contained in said tank (30), and a reagent supplier (45) capable of reacting with the oxygen and corrosive molecules present in said gas.

7. Decontamination system (1) according to claim 6, wherein said fifth module (75) further comprises an injector (756) of said reagent.

8. Decontamination system (1) according to any one of claims 1 to 7 comprising a gas cleaning device (20) which is located in said upstream pipeline (10).

9. A gas decontamination method for a gas turbine (90) test bench (80) intended to extract pollutants present in the gas stream displaced by said turbine (90) during operation, said method being characterized in that it comprises the following steps: (a) A fluid reservoir (30), an upstream pipe (10), and a downstream pipe (60) are provided, and the outlet port of said test bench (80) and the inlet port (31) of said reservoir (30) are fluidly connected to said upstream pipe (10), said inlet port (31) being located above the liquid (L) contained in said reservoir (30), and the outlet port (32) of said reservoir (30) and the atmosphere are fluidly connected to said downstream pipe (60), such that the polluted gas from said test bench (80) flows to the atmosphere through said upstream pipeline (10),through said reservoir (30) above said liquid (L) and through said downstream pipeline (60); (e) The unpolluted gas originating from said inlet pipeline (10) is discharged through said outlet pipeline (60);

10. (f) The liquid (L) contained in said reservoir (30) is recycled using a recycling device (70) which is fluidly connected upstream of said reservoir (30) by a first pipe (T1) and fluidly connected downstream of said reservoir (30) by a second pipe (T2), and which includes a rainwater recovery device (78) and a purification device (79) for said rainwater and said liquid (L) from said reservoir (30). A gas decontamination process according to claim 9, comprising a step (c) in which a reagent is put into said polluted liquid using a reagent supplier (45) and a step (d) in which oxygen is sprayed under the surface of said polluted liquid in said tank (30) using an oxygen supplier (40) in order to create a chemical reaction between the corrosive pollutant present in said gas and said reagent and oxygen.