Fish guidance structures with narrow bar spacing - Revision history

Ismailalbayrak at 09:53, 10 May 2021

2021-05-10T09:53:09Z

Bendikhansen: /* Classification table */

2021-01-26T15:54:54Z

Classification table

Bendikhansen: /* Classification table */

2021-01-26T15:44:14Z

Classification table

Bendikhansen: /* Classification table */

2021-01-26T15:42:59Z

Classification table

Bendikhansen: /* Classification table */

2021-01-26T15:41:28Z

Classification table

Bendikhansen: /* Classification table */

2021-01-26T15:36:03Z

Classification table

Bendikhansen at 14:53, 19 November 2020

2020-11-19T14:53:26Z

Bendikhansen: /* During operation */

2020-11-19T13:31:40Z

During operation

Bendikhansen at 13:31, 19 November 2020

2020-11-19T13:31:25Z

Bendikhansen: /* During planning */

2020-11-19T13:27:19Z

During planning

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 * Lemkecher F. (2020). Étude des grilles des prises d’eau ichtyocompatibles. Thesis of University of Poitiers, France.
 * Meister, J.; Fuchs, H.; Boes, R.M. (2018). Hydraulische Laboruntersuchungen horizontaler Fischleitrechen (‘Hydraulic laboratory investigations of horizontal fish guidance racks’). zekHydro, 15(2): 54–56. http://dx.doi.org/10.3929/ethz-b-000295001[in German].
-* Meister, J. (2020). Fish protection and guidance at water intakes with horizontal bar rack bypass systems. VAW-Mitteilung 258 (R.M. Boes, ed.). Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zurich, Switzerland.
+* Meister, J. (2020). Fish protection and guidance at water intakes with horizontal bar rack bypass systems. VAW-Mitteilung 258 (R.M. Boes, ed.). Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zurich, Switzerland. https://ethz.ch/content/dam/ethz/special-interest/baug/vaw/vaw-dam/documents/das-institut/mitteilungen/2020-2029/258.pdf
 * Meister, J.; Fuchs, H.; Beck, C.; Albayrak, I.; Boes, R.M. (2020a). Head Losses of Horizontal Bar Racks as Fish Guidance Structures. Water, 12(2): 475. http://dx.doi.org/10.3390/w12020475.
 * Meister, J.; Fuchs, H.; Beck, C.; Albayrak, I.; Boes, R.M. (2020b). Velocity Fields at Horizontal Bar Racks as Fish Guidance Structures. Water, 12(1): 280. http://dx.doi.org/10.3390/w12010280.

@@ Line 59: / Line 59: @@
 This article describes several different types of fish guidance structures with narrow bar spacing. The classification table does not represent all of them for every topic. Therefore, an additional table is added to highlight where and how the types differ.
-{| class="wikitable" style="text-align:center; vertical-align:bottom;"
+{| class="wikitable" style="vertical-align:bottom;"
 |- style="font-weight:bold;"
-! style="font-weight:normal; text-align:left;" |
+! style="font-weight:normal;" |
 ! Vertically inclined bar rack  (VIBR/VIPP)
 ! Angled vertical bar rack (AVBR)
@@ Line 67: / Line 67: @@
 ! Angled horizontal bar rack (HBR)
 |-
-| style="font-weight:bold; text-align:left;" | Fish species
+| style="font-weight:bold;" | Fish species
 | Tested on: smolt, European eel
 | Tested on: smolt, European eel
@@ Line 73: / Line 73: @@
 | All
 |-
-| style="font-weight:bold; text-align:left;" | Power losses
+| style="font-weight:bold;" | Power losses
 | Low head loss and symmetrical turbine admission flow
 | High head loss and mild assymetric turbine admission flow
@@ Line 79: / Line 79: @@
 | Low head loss and quasi-symmetrical turbine admission flow
 |-
-| style="font-weight:bold; text-align:left;" | Certainty of effect
+| style="font-weight:bold;" | Certainty of effect
 | Very certain
 | Very certain
 | Moderately certain
 | Very certain
-|-
+|- style="text-align:center;"
 | style="font-weight:bold; text-align:left;" | TRL
 | 9

@@ Line 59: / Line 59: @@
 This article describes several different types of fish guidance structures with narrow bar spacing. The classification table does not represent all of them for every topic. Therefore, an additional table is added to highlight where and how the types differ.
-{| class="wikitable" style="vertical-align:bottom;"
+{| class="wikitable" style="text-align:center; vertical-align:bottom;"
 |- style="font-weight:bold;"
-! style="font-weight:normal;" |
+! style="font-weight:normal; text-align:left;" |
 ! Vertically inclined bar rack  (VIBR/VIPP)
 ! Angled vertical bar rack (AVBR)
@@ Line 67: / Line 67: @@
 ! Angled horizontal bar rack (HBR)
 |-
-| style="font-weight:bold;" | Fish species
+| style="font-weight:bold; text-align:left;" | Fish species
 | Tested on: smolt, European eel
 | Tested on: smolt, European eel
@@ Line 73: / Line 73: @@
 | All
 |-
-| style="font-weight:bold;" | Power losses
+| style="font-weight:bold; text-align:left;" | Power losses
 | Low head loss and symmetrical turbine admission flow
 | High head loss and mild assymetric turbine admission flow
@@ Line 79: / Line 79: @@
 | Low head loss and quasi-symmetrical turbine admission flow
 |-
-| style="font-weight:bold;" | Certainty of effect
+| style="font-weight:bold; text-align:left;" | Certainty of effect
 | Very certain
 | Very certain
@@ Line 85: / Line 85: @@
 | Very certain
 |-
-| style="font-weight:bold;" | TRL
+| style="font-weight:bold; text-align:left;" | TRL
 | 9
 | 9

@@ Line 60: / Line 60: @@
 {| class="wikitable" style="vertical-align:bottom;"
 |-
+| style="font-weight:bold;" | Fish species
 | Tested on: smolt, European eel
 | Tested on: smolt, European eel
@@ Line 73: / Line 73: @@
 | All
 |-
-| style="background-color:#efefef;" | Power losses
+| style="font-weight:bold;" | Power losses
 | Low head loss and symmetrical turbine admission flow
 | High head loss and mild assymetric turbine admission flow
@@ Line 79: / Line 79: @@
 | Low head loss and quasi-symmetrical turbine admission flow
 |-
-| style="background-color:#efefef;" | Certainty of effect
+| style="font-weight:bold;" | Certainty of effect
 | Very certain
 | Very certain
@@ Line 85: / Line 85: @@
 | Very certain
 |-
-| style="background-color:#efefef;" | TRL
+| style="font-weight:bold;" | TRL
 | 9
 | 9

@@ Line 59: / Line 59: @@
 This article describes several different types of fish guidance structures with narrow bar spacing. The classification table does not represent all of them for every topic. Therefore, an additional table is added to highlight where and how the types differ.
+{| class="wikitable" style="vertical-align:bottom;"
 {{Fish guidance structures with narrow bar spacing}}

← Older revision		Revision as of 15:36, 26 January 2021
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	=Classification table=		=Classification table=
		+	This article describes several different types of fish guidance structures with narrow bar spacing. The classification table does not represent all of them for every topic. Therefore, an additional table is added to highlight where and how the types differ.
		+
		+
		+
	{{Fish guidance structures with narrow bar spacing}}		{{Fish guidance structures with narrow bar spacing}}

← Older revision		Revision as of 14:53, 19 November 2020
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	=Introduction=		=Introduction=
		+	[[file:IBR_schematic.png\|thumb\|250px\|Figure 1: Longitudinal view of an inclined bar rack.]]
		+	[[file:NBS_types.jpg\|thumb\|250px\|\|Figure 2: Type of fish guidance structures with narrow bar spacing: angled bar rack with vertical bars (top), vertical streamwise bars (middle), horizontal bars (bottom).]]
		+	[[file:HBR_schiffmühle.png\|thumb\|250px\|Figure 3: The horizontal bar rack bypass system at the residual flow HPP Schiffmühle, Switzerland, during revision work in July 2018.]]
		+	[[file:HBR_BS_sketch.png\|thumb\|250px\|Figure 4: Principle sketch of an HBR-BS.]]
		+	[[file:HBR_params.png\|thumb\|250px\|Figure 5: Side view of an HBR illustrating different rack parameters; ho: approach flow depth, hds: downstream flow depth, Uo: mean upstream approach flow velocity from continuity, Uds: mean downstream flow velocity, hBo: bottom overlay height, hTo: top overlay height, sb: clear bar spacing, tb: bar thickness at thickest point, db: bar depth.]]
		+	[[file:IBR_las_rives.png\|thumb\|250px\|Figure 6: Construction and installation of the inclined trash racks of the HPP of Las Rives (France).]]
		+
	Different measures are used to protect downstream moving fish (details in [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 2.1) at hydropower plants and water intakes, of which two different fish guidance structures (FGSs) with narrow bar spacing were investigated within the FIThydro project: (I) inclined bar racks and (II) horizontal bar racks.		Different measures are used to protect downstream moving fish (details in [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 2.1) at hydropower plants and water intakes, of which two different fish guidance structures (FGSs) with narrow bar spacing were investigated within the FIThydro project: (I) inclined bar racks and (II) horizontal bar racks.

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 The installation of fish guidance racks requires heavy lifting equipment and both the fixing and the placing of the structure requires a shut-down of the hydropower plant and the dewatering of the headrace channel or water intake (Figure 6). Installation of racks and a bypass system requires a suite of skilled labor on civil works.
 ==During operation==
-After the installation of a FGS with narrow or wide bar spacing, the velocity field should be measured (e.g. with an [[Acoustic Doppler current profiler (ADCP)]]) in front of the FGS, at the bypass inlet, and in the bypass for different load cases. In parallel, a fish monitoring campaign, using [[Radio telemetry|radio]]/[[Accoustic telemetry|acoustic]] telemetry or [[Radio frequency identification with passive integrated transponder (PIT tagging)|PIT-tagging]] is recommended to assess the fish protection and guidance efficiency of the FGS (FIThydro Deliverable 2.2). Efficiencies between 80% and 100% for eels and smolts are considered satisfactory. This can reduce the global mortality at a HPP to values of about 1-2% or even less, taking into account the movements via the spillway and survival rates when passing through the turbines (Tomanova, et al., 2018). The results of the monitoring campaign can be used to optimize the operation of the FGS, especially the operation of the bypass.
+After the installation of a FGS with narrow or wide bar spacing, the velocity field should be measured (e.g. with an [[Acoustic Doppler current profiler (ADCP)]]) in front of the FGS, at the bypass inlet, and in the bypass for different load cases. In parallel, a fish monitoring campaign, using [[Radio telemetry|radio]]/[[Acoustic telemetry|acoustic]] telemetry or [[Radio frequency identification with passive integrated transponder (PIT tagging)|PIT-tagging]] is recommended to assess the fish protection and guidance efficiency of the FGS (FIThydro Deliverable 2.2). Efficiencies between 80% and 100% for eels and smolts are considered satisfactory. This can reduce the global mortality at a HPP to values of about 1-2% or even less, taking into account the movements via the spillway and survival rates when passing through the turbines (Tomanova, et al., 2018). The results of the monitoring campaign can be used to optimize the operation of the FGS, especially the operation of the bypass.
 Reducing the bar spacing of the rack increases its blockage ratio and thus head losses. In addition, the rack is more quickly clogged by trash and organic fine material and hence cleaning during seasons of high floating debris transport poses a challenge. It is particularly crucial to avoid a permanent clogging by debris, which cannot be removed by the cleaning machine. Therefore, the hydraulic head losses of a FGS should be continuously measured and compared to the predictions calculated prior to construction. The head loss measurements should be also used to determine the flushing intervals of the bypass. That is, if a certain threshold value of the head losses is exceeded, the rack cleaning machine should start its operation automatically, and the bypass is opened to flush sediments and floating debris.

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 ==During implementation==
-==During operation==
+Reducing the bar spacing of the rack increases its blockage ratio and thus head losses. In addition, the rack is more quickly clogged by trash and organic fine material and hence cleaning during seasons of high floating debris transport poses a challenge. It is particularly crucial to avoid a permanent clogging by debris, which cannot be removed by the cleaning machine. Therefore, the hydraulic head losses of a FGS should be continuously measured and compared to the predictions calculated prior to construction. The head loss measurements should be also used to determine the flushing intervals of the bypass. That is, if a certain threshold value of the head losses is exceeded, the rack cleaning machine should start its operation automatically, and the bypass is opened to flush sediments and floating debris.
 =Relevant MTDs and test cases=
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 =Relevant literature=
 [[category:Downstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

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 In addition to the design of a FGS with narrow bar spacing, the bypass design is important to safely collect and transport the fish and to return them unharmed to the river downstream of an HPP. Different bypass designs are described in literature such as the full depth open channel bypass, a bypass with a bottom and top opening, and a pipe bypass. The latter is not recommended because it can clog easily and fish avoid large velocity gradients at the inlet of the pipe bypass (Beck et al., 2020). Design of the bypass for VIBR and VIPP is described in the [https://www.fithydro.eu/deliverables-tech/ FIThydro Deliverables] 2.2 and 3.4.
-The height and the width of the turbine intake influences the choice of the solution (inclined or angled). In addition, the possible location of the bypasses could modify the final solution. To reduce head losses, a particular attention has to be paid on the bar shape, the spacers and the support of the bar rack. For more details, please see the [https://www.fithydro.eu/deliverables-tech/FIThydro Deliverables] 2.2 and 3.4; and [[Fish guidance structures with wide bar spacing]].
+The height and the width of the turbine intake influences the choice of the solution (inclined or angled). In addition, the possible location of the bypasses could modify the final solution. To reduce head losses, a particular attention has to be paid on the bar shape, the spacers and the support of the bar rack. For more details, please see the [https://www.fithydro.eu/deliverables-tech/FIThydro FIThydro Deliverables] 2.2 and 3.4; and [[Fish guidance structures with wide bar spacing]].
 ==During implementation==