采礦外文翻譯---在煤礦主井通風(fēng)設(shè)備中與安全有關(guān)的控制系統(tǒng)的用途

1、<p><b>　　中文6000字</b></p><p><b>　　英文原文</b></p><p>　　THE USE OF SAFETY RELATED CONTROL SYSTEMS IN PRIMARY MINE VENTILATION RECIRCULATION SYNOPSIS</p><p>

2、　　This paper describes a ventilation problem at a large underground coal mine.The Proposals were made to provide additional limitation of conventional solutions is ventilation quantity to the inbye workings discussed,alo

3、ng with the proposed solution by recirculating part of the return air using an underground recirculation fan in back into the intake at a point some 6km the primary mine ventilation system.from the shafts.This was to be

4、achieved Foreseeable potential hazards associated by a recircu</p><p>　　The paper describes the need for emergency shutdown of the recirculation fan and the use of a programmable electronic system (PES) to m

5、onitor and automatically initiate a shutdown in the event of predetermined criteria being exceeded.The system had to be designed to ensure the stoppage of the fan on early detection of adverse conditions, but unnecessary

6、 interruption of the ventilation system when conditions were satisfactory had to be minimised.The selection and assessment of the programmable el</p><p>　　VENTILATION PROBLEM</p><p>　　Large quan

7、tities of air have to be circulated through the underground workings of coal mines to dilute mine gases, prevent accumulations of mine gases, dilute dust concentrations, and provide reasonable working environments in ter

8、ms of temperature and humidity.The resistance to ventilation in mine airways increases as the working places advance away from the TO maintain or increase the shafts.ventilation quantity may involve increasing the surfac

9、e fan capacity, installing or uprating main underg</p><p>　　LIMITATION OF COVENTI0NAL SOLUTIONS </p><p>　　At one coal mine where the undersea workings had extended over lokm from the shafts,larg

10、e surface and underground booster fans had already been installed, and leakage paths minimised.The provision of additional airway capacity would take many years to complete and by itself would be unlikely to provide a sa

11、tisfactory solution.The feasibility of sinking a shaft offshore was considered,but was not pursued due to cost, technical problems, and security.</p><p>　　PROPOSED SOLUTION AND IDENTIFICATION OF ASSOCIATED H

12、AZARDS</p><p>　　Proposals were made to provide additional ventilation quantity to the inbye workings by recirculating part of the return air back into the intake at a point some 6km from the shafts.This was

13、to be achieved by a recirculation fan of sufficient rating to overcome the pressure difference between UK the return and intake airways.Present Mining Regulations prohibit recirculation in mine ventilation systems.Howeve

14、r, selective exemptions have been granted by the Health and Safety Executive (HSE) to all</p><p>　　Partial recirculation of air does not result in a build up of contaminant gases.The concentration of a conta

15、minant gas in any ventilated region of a mine is given by the rate at which the contaminant gas enters the region divided by the flow of fresh air into the region.It does not depend on any recirculation that may be takin

16、g place [Leach and Slack.19691.</p><p>　　The most serious foreseeable hazards identified were the possible recirculation into the intake air of smoke and products of combustion or high concentrations of flam

17、mable gas (methane) [Mitche11,19891.The products of combustion resulting from an outbreak of fire, if recirculated,would prevent escape from the workings through uncontaminated air.Protection against these hazards was to

18、 be based on early detection of adverse trends, stopping the recirculation fan and reverting to conventional venti</p><p>　　THE NEED FOR AUTOMATIC SHUTDOWN</p><p>　　The need to stop the recircul

19、ation fan automatically in response to adverse considered necessary due to indications was the quantity and complexity of the environmental and associated data involved.</p><p>　　This decision was taken prio

20、r to the design stage.It was clear that automatic control would need to be provided by a microprocessor based system capable of handling and processing data from numerous transducers.Dependence on lengthy data transmissi

21、on lines to the surface control room was to be avoided and this ruled out the use of the surface computer to effect automatic control.The PE were to be installed in an underground substation near the fan.The automatic sy

22、stem would not provide for any d</p><p>　　DEVELOPMENT OF 'VOTING SYSTEM' TO INITIATE AUTOMATIC SHUTDOWN </p><p>　　Methane and carbon monoxide levels in the return air would need to be co

23、ntinuously monitored.The recirculation of return air into the intake would need to be prevented by automatically stopping the fan at predetermined levels.The intake of the recirculation circuit would additionally need to

24、 be monitored for carbon monoxide, and the fan automatically stopped at a predetermined level [see Fig 1]</p><p>　　Single environmental monitors were not satisfactory since a failure or erroneous indication

25、might lead to interruption of ventilation when conditions were satisfactory,or in the event of an erroneous indication,permit continued operation in adverse conditions.A single monitor would also require the fan to be st

26、opped for monitor replacement.</p><p>　　In a system using twin environmental monitors,although maintained in a healthy state,the failure of a single monitor would result in the fan then being controlled from

27、 the remaining monitor.</p><p>　　The use of three control environmental monitors was considered in which a failure or adverse indication from any two would initiate a stop.Conversely,for the fan to continue

28、running would require a healthy indication from at least two monitors.This 'voting system' was considered to be the most appropriate control.A single monitor failure would not stop the fan and the system would pe

29、rmit replacement of a monitor without interrupting ventilation.</p><p>　　The three sets of three monitors (two sets for carbon monoxide, and one for methane) would continuously supply data to the PE.The data

30、 would also be continuously transmitted to the surface environmental computer for information and display on thecontrol room VDU.</p><p>　　The PE would process data from the sets of environmental monitors an

31、d from other sensors.It would be programmed to interrupt the pilot circuit of the recirculation fan and initiate a trip in response to predetermined criteria.An EPROM chip programmed in a non volatile memory contained th

32、e logic for the safety related and automatic shutdown of the fan.The instructions in the EPROM could be changed only by the manufacturer thus overcoming the need for security of access by non competent people.</p>

33、<p>　　SYSTW DESCRIPTION</p><p><b>　　FIREDAMP </b></p><p>　　The Sieger BM3 methane monitor was selected as the control monitor to supply data to the programmable electronics on

34、methane levels.This instrument operates over a range of 0 - 3% with an accuracy of +/- 0.1% (from zero to 1.25%).It is powered from a d.c.supply with a built in rechargeable battery permitting up to 30 hours operation in

35、dependent of the external power supply.A set of three BM3s were installed to monitor the methane content in the return air of the recirculation circuit.The methane</p><p>　　(b) CARBON MONOXIDE </p>&l

36、t;p>　　Monitoring of carbon monoxide was considered the most reliable means of detecting the products of combustion from an outbreak of fire.The Sieger BCOl carbon monoxide monitor was selected to supply data continuou

37、sly to the PE.This instrument has three operating ranges up to 1000ppm,the appropriate range for this duty being 0 - 5Oppm.The BCOl has a similar battery back up to the BM3.The automatic stop levels were selected with du

38、e regard to operational carbon monoxide production from diesel exhaus</p><p>　　(C) RECIRCULATION FACTOR </p><p>　　The recirculation exemption specified a maximum of 37% of the return air to be r

39、ecirculated back into the intake, this proportion being known as the recirculation factor.While loss of control of the quantity recirculated in certain circumstances could lead to increased methane or carbon monoxide lev

40、els,protection was provided the arrangements previously described.$owever systems have been designed and installed to stop the recirculation fan in the event of loss of recirculation factor control.On</p><p>

41、;　　VENTILATION SHORT CIRCUIT PROTECTION </p><p>　　Stopping the recirculation fan would result in a ventilation short circuit leakage path being opened between the main intake and return airway.Since the safe

42、ty features of the recirculation system were based on automatic shutdown, the closing of anti- reversal doors to prevent short circuiting also had to be designed for automatic operation.Hinged flaps were provided at the

43、outlet side of the fan casing.These were opened by the pressure generated at the recirculation fan and closed by pressure d</p><p>　　(e)OTHER PROTECTION </p><p>　　A fire control water curtain wa

44、s installed at the outlet side of the recirculation fan.This was activated by a fusible link in a tensioned wire.Breaking the wire causes the gravity operated supply valve to open.Operation of the valve also opens an ele

45、ctrical contact resulting in an automatic stop of the fan.Vibration monitorinq ecruiDment is Drovided - fin to seise and at the recirculation indicate any developing mechanical fault.A lower vibration level gives alarm i

46、ndication.The fan is automati</p><p>　　(f)OTHER CONTINUOUS lloNITORING </p><p>　　Comprehensive continuous environmental monitoring was provided throughout the mine in addition to those sensors d

47、edicated to the control of the recirculation fan.This was provided by various strategically placed monitors supplying.data to underground outstations, which in turn relayed information to the surface HINOS (Mine Operatin

48、g System) computer via a data highway to provide records, and a display in the control room.Parameters monitored include firedamp levels, carbon monoxide levels and ai</p><p>　　A totally separate carbon mono

49、xide monitoring system was installed in the main conveyor roadways with transducers at lkm intervals.This system, known as the J Jones PDT 300 Envirosystem, had a separate data transmission highway operating on a constan

50、t current basis.This was connected to the surface control room where it received its power supply and displayed information on a VDU.Other equipment was also installed to continuously monitor the operation of the mine fi

51、redamp drainage </p><p><b>　　system.</b></p><p>　　THE PROGRAMMABLE ELECTRONIC SYSTEM</p><p>　　The complexity of the recirculating fan monitoring and control system neces

52、sitated the use of PE which when connected to the input/output transducers and linked by a data highway to the surface of the mine, forms a PES.It was decided that the PE would need to comprise two parts.The first would

53、be a microprocessor located at the fan site some</p><p>　　6km from the mine shaft and the second would be the existing surface MINOS computer with its twin DEC PDP 11/73 mini-computers.The former would be a

54、Transmittion Ltd General Purpose Monitoring and Control Unit (GPMC) type AA.It would be configured as an intelligent station with various input and output devices and would operate essentially in a "Control" mo

55、de.The latter would display information in the surface control room and operate essentially in a "Monitoring" mode.</p><p>　　This arrangement has the advantage that the safety related control funct

56、ions are dealt with locally, are independent of the surface computer and the information transmitted via the data highway is kept to a minimum.The underground PE would in addition to any other safety assessments, need to

57、 be of a type Certified by HSE(M) as suitable for use in a potentially explosive atmosphere.</p><p>　　CERTIFICATION OF PROGRAMMABLE ELECTRONICS </p><p>　　As with other electrical equipment used

58、at the underground fan site the PE needed to be certified as suitable for use in a potentially explosive atmosphere.This requirement is well known to manufacturers and users of Group I Certified Electrical Equipment (ie

59、that used in mines susceptible to firedamp).The HSE(M) certification is in two parts, a "pit worthiness assessment" and the issue of a certificate of compliance with the appropriate standard [HSE Electrical Equ

60、ipment Certification Guide 198</p><p>　　i) compliance with appropriate statutory requirements.(eg It has the necessary electrical protection and guarding required by mining law): </p><p>　　ii) c

61、ompliance with the relevant British or Harmonised European Standards relating to protection against ignition of flammable gas: </p><p>　　iii) compatibility with accepted UK mining industry practice.</p>

62、;<p>　　where the intended equipment purchaser is British Coal HSE liaises with British Coal's HQ electrical engineering staff who simultaneously carry out assessment under their "Electrical Acceptance Sch

63、eme".This avoids misunderstandings and helps manufacturers to design equipment to suit the requirements of both the industry and the legislation.</p><p>　　In the case of the recirculating fan PES, the M

64、ines Inspectorate performed the pit worthiness assessment, British Coal performed the acceptance assessment and HSE(M) Buxton certified the apparatus as complying with BS 1259:1958 as an Intrinsically Safe System compris

65、ing intrinsically safe apparatus.The non IS (power) circuits were contained within flameproof enclosures certified to BS 4683:1971 with an interface from the PES to the power circuit via a hardwired pilot circuit.The ana

66、logue signals</p><p>　　Having dealt with the flammable gas ignition risk,the legal requirements and some of the safety related aspects of the hardware,there remained a need to assess the system as a whole.&l

67、t;/p><p>　　ASSESSMENT OF TEE PES </p><p>　　i) The surface minos computer</p><p>　　The British Coal HINOS computer has operated in over 160 separate installations throughout the world.T

68、he DEC PDP hardware is used in millions of other computers.AS British Coal write and have control over their own MINOS software, there is vast experience with both the hardware and the software.This experience, coupled w

69、ith the fact that the data transmission system would also be constructed to BS 6556:1985 system,indicated that detailed safety assessment of this part of the PES would be unneces</p><p>　　ii) 輸入輸出設(shè)備The input

70、 and output devices</p><p>　　The main problem which arose in the assessment of the input/output transducers,was that of attempting to reduce the risk of failures to the unsafe mode by "Common Cause Fail

71、ure' (CCF).For example, while several types of methane monitor were available on the market all but a few operated using a "hot pellistor in a Wheatstone bridge".These are susceptible to head poisoning and

72、calibration drift when used continuously in methane concentrations of about 1% in air.In this situation doubling or tripl</p><p>　　iii) The intelligent outstation</p><p>　　This was the part of t

73、he PES in which the assessment required most attention because the available equipment was to comprise a single microprocessor with no diversity of hardware or software.</p><p>　　In an attempt to perform a l

74、ogical reliability assessment it was agreed that certain criteria be examined.To avoid duplication of effort some examinations would be performed by HSE, some by British Coal, and some jointly.</p><p>　　The

75、first of these assessments could be loosely described as "Assessing the software life cycle" to establish software quality.This assessment was based on the IEE's "Guidelines for the documentation of so

76、ftware in industrial computer systems'.</p><p>　　This comprised:</p><p>　　- examination of the concept and specification documents produced by British Coal Area and Mine Staff in consultatio

77、n　with the local HM Inspectorate:</p><p>　　- examination of the design documents to　see if they set out a logical sequence of events and contained the safety checks specified by the mining engineers:</p&g

78、t;<p>　　- examination of the programme listing to　see if its structure was in well defined　modular packages using established　routines, and containing watchdog routines,　time-outs etc.(ie checks which can be　perfo

79、rmed by an assessor even if he has　only a very limited knowledge of the　programme language)；</p><p>　　- examination of the manufacturer's maintenance manuals and operator's instructions to see if the

80、y are well written and can be understood, even by a layman:</p><p>　　- building up the PES system on the mine surface to test all inputs/outputs to the satisfaction of interested parties: </p><p&g

81、t;　　- installation and commissioning underground at the fan site,</p><p>　　- assessing the maintenance and repair procedures, especially the procedure for controlling modifications to the programme 　and iden

82、tifying the particular version in the EPROM.[NCB Mining Dept - 'Computer based Monitoring and Control Systems']</p><p>　　The final assessment considered how the intelligent outstation fitted into the

83、 installation as an entity.The use of transducer digital outputs (flashing　contacts) instead of analogue outputs to initiate safety critical circuits (eg the trip circuit), were looked at to see if it was considered that

84、 the system was acceptable.This was based on the fact that the disadvantage created by the lack of diversity in the outstation microprocessor　and its software was overcome by the above assessment in con</p><p&

85、gt;　　- the independent fire/carbon monoxide monitoring system: </p><p>　　- the B-hourly visual examination of the fan required by statute: </p><p>　　- the fact that other parts of the mine are c

86、ontinually monitored eg by Mine Deputies and environmental monitoring systems.</p><p>　　The first recirculation fan and Control system was installed in July 1986 before HSE's PES documents had been publi

87、shed.A review of the installation since then has indicated to HSE that the total configuration of the system satisfies the basic principle in the PES documents because the overall system does not depend upon one safety c

88、ritical PES.</p><p>　　TESTING OF MONITORS AND AUTOMATIC SHUTDOWN SYSTEM</p><p>　　A detailed procedure for calibration, testing and maintenance of the monitors, the PE, the data transmission and

89、associated equipment is specified in rules drawn up and implemented by the mine Manager [Robinson and Harrison 19871.The procedure includes systematic on-site testing of the accuracy of monitors,comparing the readings wi

90、th hand held instruments of known accuracy, and replacing these as required.Additionally for each set of three 'voting' monitors,should the spread of readings exceed 0</p><p>　　Automatic shutdown of

91、the recirculation fan in response to excess methane or carbon monoxide levels requires two out of three monitors in one of the controlling sets to exceed the trip levels.Shutdown also depends on the receipt of this data

92、at the outstation,the correct interpretation of the data by the PE, the appropriate output to interrupt the pilot circuit, the operation of the pilot circuit breaker and the operation of the fan switchgear [see Fig 21.Th

93、e testing procedure includes monthly t</p><p>　　CONCLUSION</p><p>　　The safety related PES of the recirculation fan has worked satisfactorily for over three years, providing additional ventilati

94、on quantity and improved environmental conditions in the, undersea workings of a large coal mine.The associated comprehensive environmental monitoring system has enhanced the level of safety.The testing procedures descri

95、bed have given a high confidence level that in the event of excess concentrations of methane or carbon monoxide safety related systems will function as de</p><p><b>　　中文譯文</b></p><p>

96、;　　在煤礦主井通風(fēng)設(shè)備中與安全有關(guān)的控制系統(tǒng)的用途</p><p><b>　　摘要</b></p><p>　　本文描述了一個(gè)大型地下煤礦的通風(fēng)問題，并對常規(guī)解決方案的限制進(jìn)行了討論，同時(shí)提出在煤礦主井中使用地下對流風(fēng)扇的解決方案。在提出的解決方案中，也提及了一些可預(yù)知的潛在危險(xiǎn)。</p><p>　　本文介紹了循環(huán)風(fēng)機(jī)緊急停機(jī)的需要和如何

97、使用一個(gè)可編程的電子監(jiān)測系統(tǒng)（PES）并在超出預(yù)設(shè)標(biāo)準(zhǔn)的情況下自動啟動關(guān)機(jī)。所設(shè)計(jì)的自動關(guān)機(jī)系統(tǒng)必須滿足以下條件，一方面必須盡早發(fā)現(xiàn)不利因素，另一方面風(fēng)扇在正常運(yùn)轉(zhuǎn)時(shí)所受的不必要的干擾程度需降至最低。本文概述了如何選擇和評估可編程的電子系統(tǒng)以及如何選擇和放置檢測各種參數(shù)數(shù)據(jù)的傳感器，同時(shí)也介紹了如何使用一個(gè)被編寫程序控制的傳感器投票系統(tǒng)來測定傳感器的使用性能，以及時(shí)發(fā)現(xiàn)需要更換的傳感器。</p><p>　　礦井

98、通風(fēng)問題，大量的空氣要通入到煤礦井下去稀釋礦井中的氣體，防止煤礦瓦斯氣體的積累，稀釋粉塵濃度，并提供適合的工作面溫度和濕度。礦井通風(fēng)中的阻力會隨著工作點(diǎn)離礦口越遠(yuǎn)而不斷增加。保持或增加通風(fēng)效果要求增加地表風(fēng)扇的效能，安裝或增加地下主風(fēng)扇（增壓風(fēng)機(jī)），盡量減少入風(fēng)和出風(fēng)路徑之間的漏風(fēng)通道，提供額外的通風(fēng)能力，或挖掘更多的入口或鉆孔。</p><p>　　在傳統(tǒng)解決方案中的缺陷，一個(gè)從井口向下延伸了10米的礦井中，安

99、裝了數(shù)個(gè)地表大型風(fēng)扇和增壓風(fēng)機(jī)，也堵住了滲漏通道，提供額外的通風(fēng)能力也需要數(shù)年來完成，而且其本身提供的不是一個(gè)令人滿意的解決方案。從理論上來說鉆挖井口是可行的，但由于成本，技術(shù)問題和安全性沒有得以實(shí)施。</p><p>　　以下提出了通過在出風(fēng)口離井口6公里處的地方循環(huán)利用部分出風(fēng)以增加對附近礦井通風(fēng)量的建議。這是通過一個(gè)循環(huán)式的風(fēng)扇實(shí)現(xiàn)的，這個(gè)風(fēng)扇有足夠的動力來克服入風(fēng)通道和出風(fēng)通道之間的壓力差。目前，英國礦業(yè)