Vibrasjoner, støt- og vibrasjonsmålinger

This document provides guidelines for the assessment of torsional natural frequencies and component strength, under normal operating conditions, for the coupled shaft train, including long rotor blades, of steam and gas turbine generator sets. In particular, the guidelines apply to the torsional responses of the coupled shaft train at grid and twice grid frequencies due to electrical excitation of the electrical network to which the turbine generator set is connected. Excitation at other frequencies (e.g. subharmonic frequencies) are not covered in this document. No guidelines are given regarding the torsional vibration response caused by steam excitation or other excitation mechanisms not related to the electrical network. Where the shaft cross sections and couplings do not fulfil the required strength criteria and/or torsional natural frequencies do not conform with defined frequency margins, other actions shall be defined to resolve the problem. The requirements included in this document are applicable to

a) steam turbine generator sets connected to the electrical network; and

b) gas turbine generator sets connected to the electrical network.

Methods currently available for carrying out both analytical assessment and test validation of the shaft train torsional natural frequencies are also described.

NOTE Radial (lateral, transverse) and axial vibration of steam and/or gas turbine generator sets is dealt with in ISO 20816-2.

<p>This document describes the general requirements for evaluating the vibration of various coupled industrial machine types with a power above 15 kW and operating speeds between 120 min^-1 and 30 000 min^-1 when measurements are made in-situ. Guidelines for applying evaluation criteria are provided for measurements taken on non-rotating and rotating parts under normal operating conditions. The guidelines are presented in terms of both steady running vibration and any changes to vibration amplitude, which can occur in these steady values. The numerical values presented are intended to serve as guidelines based on worldwide machine experience, but shall be applied with due regard to specific machine features which may cause these values to be inappropriate. In general, the condition of a machine is assessed by consideration of both the shaft vibration and the associated structural vibration, as well as specific frequency components, which may not relate to the broadband severity values presented.</p><p>The machine types covered by this document include:</p><list list-type="alpha-lower"><list-item><label>a)</label><p>steam turbines and generators with outputs less than or equal to 40 MW (see Note 1 and Note 2);</p></list-item><list-item><label>b)</label><p>steam turbines and generators with outputs greater than 40 MW which normally operate at speeds other than 1 500 min^-1, 1 800 min^-1, 3 000 min^-1 or 3 600 min^-1 (although generators seldom fall into this category) (see Note 1 and Note 2);</p></list-item><list-item><label>c)</label><p>rotary compressors (see Note 2);</p></list-item><list-item><label>d)</label><p>industrial gas turbines with outputs less than or equal to 3 MW (see Note 2 and Note 3);</p></list-item><list-item><label>e)</label><p>turbofans (see Note 2);</p></list-item><list-item><label>f)</label><p>electric motors of any type (see Note 4);</p></list-item><list-item><label>g)</label><p>rolls and mills (see Note 5);</p></list-item><list-item><label>h)</label><p>conveyors (see Note 5);</p></list-item><list-item><label>i)</label><p>variable speed couplings;</p></list-item><list-item><label>j)</label><p>blowers or fans (see Note 6).</p></list-item></list><non-normative-note><label>NOTE 1</label><p>Land based steam turbines, gas turbines and generators of greater than 40 MW capacity, which run at 1500 min^-1, 1800 min^-1, 3000 min^-1 or 3600 min^-1 are covered by the requirements of <std std-id="iso:std:iso:20816:-2:en" type="undated"><std-ref>ISO 20816-2</std-ref></std>; generators in hydro-electric plants are covered by <std std-id="iso:std:iso:20816:-5:en" type="undated"><std-ref>ISO 20816-5</std-ref></std>;</p></non-normative-note><non-normative-note><label>NOTE 2</label><p>The proposed part 10 of this series of standards will be developed to cover high speed turbo-machinery. When that is completed, some machine types will be excluded from the scope of this document.</p></non-normative-note><non-normative-note><label>NOTE 3</label><p>Gas turbines of power greater than 3 MW are covered by <std std-id="iso:std:iso:20816:-4:en" type="undated"><std-ref>ISO 20816-4</std-ref></std></p></non-normative-note><non-normative-note><label>NOTE 4</label><p>When a motor is coupled to a machine covered by another part of <std std-id="iso:std:iso:20816:en" type="undated"><std-ref>ISO20816</std-ref></std>, the motor falls under this part if the coupling is flexible, but falls under the other standard if the coupling is rigid;</p></non-normative-note><non-normative-note><label>NOTE5</label><p> Machinery including a geared stage can fall under the scope of this document. However, the information relating to gearboxes - in particular, the conditions for performing acceptance tests and the influence of operating conditions (given in <std std-id="iso:std:iso:20816:-9:en" type="undated"><std-ref>ISO 20816-9</std-ref></std>) - shall be taken into account when evaluating the vibration of gearboxes;</p></non-normative-note><non-normative-note><label>NOTE 6</label><p>The vibration criteria presented in this document are generally only applicable to fans with power ratings greater than 300 kW or fans which are not flexibly supported. As and when circumstances permit, recommendations for other types of fans, including those of lightweight sheet-metal construction, will be prepared. Until these recommendations are available, classifications can be agreed between the manufacturer and the customer, using results of previous operational experience, see also <std std-id="iso:std:iso:14694:en" type="undated"><std-ref>ISO 14694</std-ref></std>^[<xref ref-type="bibr" rid="ref_8">⁴</xref>^].</p></non-normative-note><p>The following types of industrial machine are excluded from this document:</p><list list-type="alpha-lower"><list-item><label>k)</label><p>land-based gas turbines, steam turbines and generators with power outputs greater than 40 MW and speeds of 1 500 min^-1, 1 800 min^-1, 3 000 min^-1 or 3 600 min^-1 (see <std std-id="iso:std:iso:20816:-2:en" type="undated"><std-ref>ISO 20816-2</std-ref></std>);</p></list-item><list-item><label>l)</label><p>gas turbine sets with power outputs greater than 3 MW (see <std std-id="iso:std:iso:20816:-4:en" type="undated"><std-ref>ISO 20816-4</std-ref></std>);</p></list-item><list-item><label>m)</label><p>machine sets in hydraulic power generating and pumping plants (see <std std-id="iso:std:iso:20816:-5:en" type="undated"><std-ref>ISO 20816-5</std-ref></std>);</p></list-item><list-item><label>n)</label><p>reciprocating machines and machines solidly coupled to reciprocating machines (see <std><std-ref>ISO 20816-6</std-ref></std>)<?authorquery AU5: Not found: &#x0022;ISO&#x00A0;20816&#x2011;6&#x0022;?>;</p></list-item><list-item><label>o)</label><p>rotodynamic pumps and any integrated or solidly coupled electric motors where the impeller is mounted directly on the motor shaft or is rigidly attached to it (see <std std-id="iso:std:iso:10816:-7:en" type="undated"><std-ref>ISO 10816-7</std-ref></std>);</p></list-item><list-item><label>p)</label><p>reciprocating compressor systems (See <std std-id="iso:std:iso:20816:-8:en" type="undated"><std-ref>ISO 20816-8</std-ref></std>);</p></list-item><list-item><label>q)</label><p>rotary positive displacement compressors (e. g. screw compressors);</p></list-item><list-item><label>r)</label><p>submerged motor-pumps;</p></list-item><list-item><label>s)</label><p>wind turbines (see <std std-id="iso:std:iso:10816:-21:en" type="undated"><std-ref>ISO 10816-21</std-ref></std>).</p></list-item></list><p>The requirements of this document apply to in-situ broad-band vibration measurements taken on the shafts, bearings, bearing pedestals, or housings of machines under steady-state operating conditions within their nominal operating speed range. The requirements relate to both acceptance testing and operational monitoring. The evaluation criteria included in this document can be applied to both continuous and non-continuous monitoring situations.</p><p>The requirements of this document cover machines which may have gears or rolling element bearings, but do not address the diagnostic evaluation of the condition of those gears or bearings. (See <std std-id="iso:std:iso:20816:-9:en" type="undated"><std-ref>ISO 20816-9</std-ref></std>).</p><p>The requirements in this standard are applicable only for the vibration produced by the machine set itself and not for vibration which is transmitted to the machine set from external sources.</p>