1、BRITISH STANDARD BS 6880-2: 1988 Code of practice for Low temperature hot water heating systems of output greater than 45 kW Part 2: Selection of equipment UDC 621.181.25:621.18.064:697.27:697.326BS6880-2:1988 This British Standard, having been prepared under the directionof the Refrigeration, Heati
2、ng and Air Conditioning Standards Committee, was published under the authority ofthe Board of BSI and comes into effect on 29 February1988 BSI 03-1999 The following BSI references relate to the work on this standard: Committee reference RHE/23 Draft for comment 85/70687 DC ISBN 0 580 16027 0 Committ
3、ees responsible for this British Standard The preparation of this British Standard was entrusted by the Refrigeration, Heating and Air Conditioning Standards Committee (RHE/-) to Technical Committee RHE/23, upon which the following bodies were represented: Association of Consulting Engineers British
4、 Combustion Equipment Manufacturers Association British Gas plc Building Services Research and Information Association Chartered Institution of Building Services Engineers Department of Health and Social Security Department of the Environment (Property Services Agency) Electricity Supply Industry in
5、 England and Wales Health and Safety Executive Hevac Association Institute of Refrigeration Institution of Gas Engineers Ministry of Defence Royal Institute of British Architects Sealed Expansion Vessel Association Amendments issued since publication Amd. No. Date of issue CommentsBS 6880-2:1988 BSI
6、 03-1999 i Contents Page Committees responsible Inside front cover Foreword ii Section 1. General 1.1 Scope 1 1.2 Definitions 1 Section 2. Principal equipment groups and standards 2.1 Principal equipment groups 2 2.2 Equipment standards 2 Section 3. Utilization equipment 3.1 Natural convectors: type
7、s 3 3.2 Natural convectors: selection factors 6 3.3 Forced convectors: types 8 3.4 Forced convectors: selection factors 13 3.5 Heated ceilings and walls: types 16 3.6 Heated ceilings and walls: selection factors 18 3.7 Floor heating systems: types 18 3.8 Floor heating systems: selection factors 22 S
8、ection 4. Distribution equipment 4.1 General 24 4.2 Circulating pumps: types 24 4.3 Circulating pumps: selection factors 25 4.4 Pressurization equipment: types 28 4.5 Pressurization equipment: selection factors 33 Section 5. Energy conversion equipment 5.1 Boilers and combustion equipment: types 34
9、5.2 Boilers and combustion equipment: selection factors 42 5.3 Boiler and combustion ancillaries: types 42 5.4 Boiler and combustion ancillaries: selection factors 50 5.5 Heat exchangers and thermal storage vessels: types 51 5.6 Heat exchangers: selection factors 55 5.7 Direct electric energy conver
10、sion equipment 56 5.8 Heat pumps: types 57 5.9 Heat pumps: selection factors 64 Section 6. Automatic controls, instrumentation and monitoring 6.1 Control loops and sensing elements: types 68 6.2 Controllers: types 69 6.3 Controlled devices: types 71 6.4 Centralized control and monitoring: types 78 6
11、.5 Controls: selection factors 78 Appendix A Bibliography 80 Figure 1 Common radiator connections 4 Figure 2 Typical continuous natural convector types (section at wall) 7 Figure 3 Typical forced convector types 9 Figure 4 Typical arrangement of vertical and horizontal industrial unit heaters showin
12、g key dimensions 11 Figure 5 Principal elements of floor heating system 21 Figure 6 Typical circulating pump types 26BS6880-2:1988 ii BSI 03-1999 Page Figure 7 Pump characteristics and selection29 Figure 8 Principal elements of feed and expansion systems 30 Figure 9 Typical arrangement of horizontal
13、 (above ground) oil storage tanks 44 Figure 10 Typical hot-oil ring main arrangement 47 Figure 11 Principal tube heat exchanger (calorifier) types 53 Figure 12 Plate type heat exchanger 54 Figure 13 Principal elements of heat pump system 59 Figure 14 Typical expansion valve arrangements 61 Figure 15
14、 Basic heat pump performance concepts 66 Figure 16 Form of heat output and power input data for varying operating conditions 67 Figure 17 Simple on/off control loop 68 Figure 18 Simple modulating control loop 69 Figure 19 Typical compensator schedule 70 Figure 20 Typical control valves 72 Figure 21
15、Typical two-port control valve application 73 Figure 22 Typical three-port control valve applications 75 Figure 23 Typical control valve characteristics 76 Table 1 Maximum tolerable air velocities 15 Table 2 Maximum floor surface temperatures 22 Table 3 Pressure and temperature classes for circulati
16、ng pumps complying with BS 1394-1 27 Table 4 Density of water 33 Table 5 Recommended minimum boiler operating efficiencies (50 % to 100 %) full load 35 Table 6 Maximum working pressures and temperatures for calorifiers complying with BS 853 (grade A) 51 Table 7 Recommendations for control valve auth
17、ority 73 Table 8 Recommended control valve characteristics 77 Publications referred to 82BS6880-2:1988 BSI 03-1999 iii Foreword This Part of BS6880 has been prepared under the direction of the Refrigeration, Heating and Air Conditioning Standards Committee. BS 6880 is published in three Parts which
18、together form a full technical revision of CP341.300-307:1956 which is withdrawn. This Part gives recommendations on the selection of equipment for low temperature hot water heating systems. The other two Parts are: Part 1: Fundamental and design considerations; Part 3: Installation, commissioning a
19、nd maintenance. The policy adopted when writing this code has been to avoid repetition of material for which other bodies are the accepted authority, except in so far as limited extraction assists the understanding of this code. Consequently the code provides general recommendations only on certain
20、topics. References in this category are as follows. a) For detailed procedures: 1) publications of the Chartered Institution of Building Services Engineers (CIBSE), particularly: i) CIBSE Guide 1; ii) CIBSE Building Energy Code 2; iii) technical memoranda relating to fire in buildings; iv) practice
21、notes relating to provision of combustion and ventilation air for boiler installations; 2) handbooks published by the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE). b) For detailed commissioning arrangements: 1) CIBSE commissioning codes; 2) application guides pu
22、blished by the Building Services Research and Information Association (BSRIA). It should be noted that references to such applications are deemed to refer to the current edition, whereas specific extracts reproduced in this code are from the edition current at the time of preparation of this code. W
23、hilst the recommendations made in this code generally relate to current practice, they are not intended to inhibit the use of innovative systems or equipment which an experienced designer considers appropriate to the application, and which meet all statutory requirements and the safety and general g
24、ood practice recommendations of this code. It is desirable that the principal interested parties should be made aware of such proposals at the design stage. Reference is made in the text to a number of Acts of Parliament and to various regulations made under them. Such lists are necessarily incomple
25、te, and in any particular circumstance the users of this code should acquaint themselves with the relevant regulations in force at the time. Attention is drawn to the requirements of the Building Regulations of England and Wales, of Scotland, Northern Ireland and of Inner London.BS6880-2:1988 iv BSI
26、 03-1999 A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document c
27、omprises a front cover, an inside front cover, pages i to iv, pages 1 to 82, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS6880-2:1988 BSI
28、03-1999 1 Section 1. General 1.1 Scope This Part of BS6880 gives recommendations regarding the types of low temperature hot water (see1.2.1) heating equipment which are in common use and the selection of such equipment when designing low temperature hot water heating systems of output greater than45
29、kW, open vented or sealed. It is primarily intended for use by building owners, building managers, installers and associated professionals. It is not intended to serve as a detailed design guide (see foreword). The recommendations recognize the need to optimize the use of energy, reduce hazards and
30、minimize effects detrimental to the environment. Solar heating is outside the scope of this code. NOTEThe titles of the British Standards publications referred to in this standard are listed on page 82. References in the text to other publications are identified in the text by numbers in square brac
31、kets, and are listed inAppendix A. 1.2 Definitions For the purposes of this Part of BS6880 the definitions given in BS1523, BS3533 and BS5643 apply together with the following. NOTESee also the CIBSE Building Energy Code 2. 1.2.1 low temperature hot water (LTHW) water used as the heating medium such
32、 that its temperature does not exceed100C at any point in the system, whether open or sealed NOTEVarious safety considerations may require that the actual design flow temperature of an LTHW system should be significantly less than100C (see SectionB.1 of the CIBSE Guide 1, HSE Guidance Note PM5 3 and
33、 section3 of BS6880-1:1988). 1.2.2 boiler an appliance designed for heating water either for space heating or for space heating combined with hot water supply 1.2.3 heat emitters equipment emitting heat for the purpose of space heating NOTEThis equipment includes radiators, convectors, skirting heat
34、ing and radiant panels. 1.2.4 radiator a unit for space heating that warms the air by convection and provides radiationBS6880-2:1988 2 BSI 03-1999 Section 2. Principal equipment groups and standards 2.1 Principal equipment groups The following classification into subsystems (see also3.1 of BS6880-1:
35、1988) is used in this code. a) Utilization equipment (see section3). This is further classified in terms of natural convectors, forced convectors and floor, wall and ceiling panel systems. b) Distribution equipment (see section4). This includes circulating pumps and other equipment associated with d
36、istribution of LTHW from energy conversion to utilization equipment. c) Energy conversion equipment (see section5). This is further classified in terms of boilers and combustion equipment, boiler ancillaries and unfired heat sources (see3.1.4 of BS6880-1:1988). d) Automatic controls, instrumentation
37、 and monitoring (see section6). These are considered in relation to individual subsystems and the overall system. 2.2 Equipment standards 2.2.1 New and existing equipment This code presupposes that new equipment is being installed. Where it is proposed to modify an existing installation or retain el
38、ements of it in an otherwise new installation, the extent of reuse of equipment should be established and understood by all interested parties at the outset, and steps taken to ensure its fitness for the purpose intended and compatibility between new and existing elements. 2.2.2 Compliance with Brit
39、ish Standards Equipment and materials should comply with British Standards where applicable. 2.2.3 Uniformity of equipment Equipment intended to be similar which is incorporated in systems forming part of a single installation should be of uniform type and manufacture, to the extent that the needs o
40、f the application and performance factors allow. 2.2.4 Statutory compliance Attention is drawn to the need for all equipment supplied for use in LTHW heating installations to meet the requirements of all relevant UK legislation (see2.4 of BS6880-1:1988); in addition to matters of safety this may ext
41、end to energy conservation and other matters. It is desirable that each individual item of equipment should so comply on arrival at the job site; it is necessary that it should so comply before putting it into use. 2.2.5 Energy conservation It is a recommendation of this code that any LTHW system sh
42、ould at least meet the minimum energy conservation recommendations of the CIBSE Building Energy Code 2 (see2.5 of BS6880-1:1988). This includes certain recommendations in respect of the performance of individual items of equipment, noting that there may also be overruling statutory requirements in t
43、his context.BS 6880-2:1988 BSI 03-1999 3 Section 3. Utilization equipment 3.1 Natural convectors: types 3.1.1 General This clause considers various types of heat emitter which operate primarily by natural convection, both unitary and continuous (or perimeter) types. Unitary types are individually co
44、nnected to the LTHW distribution subsystem. A number of such emitters may be used on one system, of various sizes; in certain circumstances a system may include more than one type. Thermal ratings, construction, test pressures, etc. are covered by BS3528, with which they should comply. See also Tabl
45、eB.1.39 of the CIBSE Guide 1. 3.1.2 Radiators 3.1.2.1 General. Despite their name, approximately70% of the heat emission from LTHW radiators is by natural convection; some types use extended surfaces to increase the convective effect. The principal distinction between radiators and unitary natural c
46、onvectors (see3.1.5) is that in the former, the heat emitting surface is normally directly exposed to the room, unless guards are fitted. They are very widely used and are available in various types, materials and finishes for unit outputs up to around6kW. 3.1.2.2 Construction 3.1.2.2.1 Panel type.
47、This is the most common type, usually manufactured from steel pressings welded together. These are commonly available as single panels and double panels (two single panels operating as one parallel connected unit) and variants of these with extended convection surfaces, often termed convector radiat
48、ors. It should be noted that heat emission occurs from both front and back surfaces (see3.2.3.7 of BS6880-1:1988 in respect of back loss), also that the output of double panel radiators is significantly less than twice that of the corresponding single panel type. They are usually manufactured in a l
49、imited number of standard heights primarily selected to suit installation below windows, different outputs are obtained by variation of length over a wide range, usually in small modular increments. The method of forming the top edge may be a relevant safety consideration in certain applications, in which case smooth edge types are preferable. Steel panel radiators are particularly prone to corrosion and the recommendations of3.5 of BS6880-1:1988 should be followed. The development of LTHW heat
