1、BRITISH STANDARD BS4856-1: 1972 Methods for Testing and rating fan coil units, unit heaters and unit coolers Part1: Thermal and volumetric performance for heating duties; without additional ducting UDC 697.356.001.42+697.971.001.42BS4856-1:1972 This British Standard, having been approved by the Refr
2、igeration, Heating and AirConditioning Industry Standards Committee, was published under the authority of the Executive Board on 13October1972 BSI 08-1999 The following BSI references relate to the work on this standard: Committee reference RHE/6 Draft for comment70/37568 ISBN 0 580 07323 8 Co-opera
3、ting organizations The Refrigeration, Heating and Air Conditioning Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Association of Consulting En
4、gineers* Association of Manufacturers of Domestic Electrical Appliances Boiler and Radiator Manufacturers Association* British Mechanical Engineering Confederation British Oil and Gas Firing Equipment Manufacturers Association British Refrigeration and Air Conditioning Association* Department of Hea
5、lth and Social Security* Department of the Environment Electricity Council, The Central Electricity Generating Board and the Area Boards in England and Wales Engineering Equipment Users Association Gas Council Heating and Ventilating Contractors Association* Heating and Ventilating Research Associat
6、ion* HEVAC Association* Institute of Fuel Institute of Refrigeration* Institution of Electrical Engineers Institution of Gas Engineers Institution of Heating and Ventilating Engineers* Lloyds Register of Shipping Ministry of Defence, Navy Department* National Coal Board Royal Institute of British Ar
7、chitects Water-tube Boilermakers Association The Government departments and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Department o
8、f the Environment, Building Research Station Greater London Council Oil Appliances Manufacturers Association Steel Radiators absolute pressure,1.013bar 1) ; relative humidity,43%; density,1.200kg/m 3 3 Operating characteristics of units 3.1 The primary medium shall be any of the following fluids: Wa
9、ter Steam Heat transfer fluid (excluding primary refrigerants). 3.2 The operating conditions of the units shall lie within the following ranges: Water up to100 C Pressurized water from100 C to200 C Steam between atmospheric pressure and a gauge pressure of8bar 1) Heat transfer fluid up to100 C for a
10、tmospheric pressure and from100 C to200 C when pressurized. 3.3 The air volume flow rate of the unit shall lie within the range25 10 3m 3 /s to5m 3 /s. 3.4 There is no restriction on the mounting of these units, provided that they are tested while mounted in a way representative of their intended us
11、e. 3.5 The requirements of the methods for individual tests may be followed to determine the performance of a unit at one specified set of conditions; where the performance at conditions other than those of the actual test are to be stated, the full schedule of tests specified in the standard is to
12、be completed. 1) 1bar=10 5N/m 2 .BS4856-1:1972 2 BSI 08-1999 4 Nomenclature 5 Objects of the test method The object of the tests is to establish the performance of the unit over a specified range of primary and secondary fluid conditions and space temperatures. The test procedures set out in this st
13、andard are for the determination of: 1) the gross thermal output; 2) the primary fluid pressure drop; 3) the secondary flow rate, where required. 6 Testing conditions 6.1 Primary fluidliquid. The unit shall be tested at a minimum of three primary fluid inlet temperatures. The selected temperatures s
14、hall cover the range of duty over which the appliance is to be rated, that is, to within10% at either end of the range. Suitable inlet temperatures may be: For inlet temperature up to100 C: at50 C,70 C,90 C. For inlet temperature between100 C and200 C: at130 C,150 C,180 C. Symbol Quality Unit c p sp
15、ecific heat capacity kJ/kg C K w temperature correction factor L latent heat of evaporation kJ/kg M total mass flow of liquid kg M t net weight of condensate formed during test kg M n net weight of condensate formed during no load kg %p primary fluid pressure drop N/m 2 %p r primary fluid pressure d
16、rop at a reference temperature of80 C N/m 2 Q rate of heat emission kW Q a rate of heat emission based on true inlet air temperature kW Q m rate of heat emission based on room air temperature kW q r air volume flow rate at reference conditions m 3 /s q f primary fluid volume flow rate m 3 /s q fr pr
17、imary fluid volume flow rate at reference temperature of80 C m 3 /s r reference air density kg/m 3 m air density at test conditions kg/m 3 f primary fluid density at mean liquid temperature kg/m 3 fr primary fluid density at reference temperature of80 C kg/m 3 T t duration of test s T n duration of
18、no load test s t a entering air temperature C t i inlet liquid temperature C t o outlet liquid temperature C t R room air temperature C t 3 saturated steam temperature C w liquid mass flow rate kg/sBS4856-1:1972 BSI 08-1999 3 6.2 Primary fluidsteam. Gauge pressures for the tests shall be selected su
19、ch that temperature intervals are not greater than20 C, and that a minimum of three test points are obtained. The steam shall have a minimum of1.5 C superheat to ensure the absence of entrained moisture, and a maximum of3 C superheat. 6.3 Entering air conditions. The entering air temperature shall b
20、e within the range15 25 C. 6.4 Primary fluid flow rate. For duties quoted over a range of primary fluid flow rates, tests shall be carried out at a minimum of three primary fluid flow rates, spaced approximately equally over the required range and covering the range to within10% at either end. 6.5 E
21、lectrical supply conditions. The tests shall be carried out at the rated voltage and frequency of theunit. 7 Steady state conditions Tests shall be carried out under steady state conditions and these are considered to be established if during30min the measurements given in Table 1 do not vary by mor
22、e than the specified amount. Table 1 Steady state conditions 8 Instrumentation 8.1 Steam 8.1.1 Temperature. Temperature measurement shall comply with the requirements of BS1041-2, BS1041-3 and BS1041-4. Thermometers, thermocouples and resistance thermometers shall be calibrated to a precision of0.5
23、C against a NPL thermometer (accurate to0.25 C) and shall be used in pockets similar to those shown in Figure 1a, situated at the entry and outlet of the unit between100mm and200mm for the unit connections. 8.1.2 Pressure. Pressure gauges shall comply with the requirements of Clause 30a of BS1780:19
24、60. They shall be at least150mm in diameter and shall have a total scale range not more than three times the measured test pressure. For test pressures below0.3bar, a liquid manometer is desirable. 8.1.3 Mass flow. Mass flow measurement shall be by weight of condensate. The weighing apparatus shall
25、not have an error greater than5g over the range of weights used in the test. 8.2 Hot water 8.2.1 Temperature. The measurement of temperature of the water at entry and exit shall comply with the requirements of BS1041. If liquid-in-glass thermometers are used, they shall be graduated for partial imme
26、rsion at intervals of0.1 C and shall comply with the requirements of BS593. Thermometers, thermocouples and resistance thermometers shall be calibrated to a precision of0.1 C against a NPL thermometer (accurate to0.05 C) and shall be used in pockets similar to those shown in Figure 1b, situated at t
27、he entry and outlet of the unit between100mm and200mm from the unit connections. 8.2.2 Pressure. The pressure drop across the unit shall be measured with an inverted U-tube manometer similar to that shown in Figure 2. The manometer shall be vertical and calibrated in intervals not exceeding2% of the
28、 measured drop. 8.2.3 Mass flow. Mass flow shall be preferably measured by direct weighing. Weighing machines shall have an error of not greater than 50g over the range of weights used in the test. Collecting vessels shall not weigh more than50% of their normal contents. Flow rate may also be measur
29、ed by means of an orifice plate installed in accordance with BS1042-1. Quantity Permitted variation from mean Room air temperature, as defined in11.1 Entering air temperature, as defined in11.2 Entering liquid temperature Liquid flow rate Steam rate of condensation Supply voltage 0.5 C 0.5 C 0.5 C r
30、ange: less than100 C 1 C range: between100 C and200 C 2% 3% 2.5% of rated voltage. BS4856-1:1972 4 BSI 08-1999 8.3 Air 8.3.1 Temperature. Measurements of air temperature shall be made with mercury-in-glass thermometers, thermocouples or resistance thermometers, calibrated to0.1 C against a NPL Class
31、 A thermometer. Thermometers shall be graduated at intervals not greater than0.1 C and calibrated for total immersion. Temperature measuring instruments shall be shielded against radiation; suitable shields are shown in Figure 3. Inlet air temperatures shall be measured by thermocouples or resistanc
32、e thermometers capable of being shielded as in Figure 3b. 8.3.2 Flow rate. Flow meters should comply with the requirements of BS1042-1. Where the recommendations of BS1042-1 cannot be followed, the flow meter may be calibrated in situ. It is suggestedthat the orifice plate at the junction of a void
33、and duct be employed, as described in Clause 49 ofBS1042-1:1964. 8.3.3 Pressure 8.3.3.1 The minimum differential pressure readings for flow measurement shall be25N/m 2for inclined U-tube manometers and micro-manometers, and500N/m 2for vertical U-tube manometers. 8.3.3.2 Manometers shall be calibrate
34、d against an accepted standard. 8.3.3.3 It shall be possible to read the manometer to an accuracy of0.5N/m 2over a pressure differential of2550N/m 2and to1% at higher differential pressures. 9 Test equipment 9.1 Steam. The steam supply and consumption test equipment shall be as detailed below and ar
35、ranged as shown in Figure 4. 9.1.1 The length of pipe between the steam pressure and temperature measurement positions and the unit casing shall not exceed300mm and shall be insulated with at least40mm thickness of insulating material having a thermal conductivity not exceeding0.06W/m C. 9.1.2 The p
36、ipe conveying the condensate to the sight glass shall not exceed a total length of1m and shall be insulated as described in9.1.1. 9.1.3 An air cock, throttle valve, pressure gauge or manometer, a temperature measuring instrument and a separator with drain shall be fixed in the steam pipe close to th
37、e steam inlet of the unit, as means for controlling and indicating the steam pressure and temperature. The use of a superheater, preferably electrically heated, is also advisable. 9.1.4 An air cock, automatic or otherwise, a sight glass with water level indicator and a throttle valve shall be fixed
38、close to the heater condensate outlet. 9.1.5 The condensate shall be collected and weighed and means shall be employed to minimize loss by evaporation. An after-cooler may be employed, if desired. 9.2 Hot water or heat transfer fluid 9.2.1 There shall be available a means for providing a continuous
39、supply of heated fluid, together with a means for controlling the temperature of this fluid at any desired temperature that may be required for thetest. 9.2.2 There shall be available a means for providing a constant flow of fluid, such as a constant head tank or a circulation pump. 9.2.3 Figure 5 s
40、hows the arrangement of the hot water test equipment. 9.2.4 For water temperatures above95 C, a closed pressure vessel such as a boiler operating at constant pressure should be used as the source of hot water, and an after-cooler inserted before the water control valve at the discharge end. A typica
41、l arrangement is shown inFigure 6. 9.2.5 The pipework shall be arranged to give an unobstructed straight run at entry to and exit from the appliance, the pipe diameter being equal to that demanded by the unit connections and of length at least equal to five pipe diameters. 9.2.6 Hydraulic resistance
42、 side wall tappings shall be adjacent to the connection to the appliance. The tappings shall be as specified inFigure 7 and connected to form a piezometric ring. 9.2.7 The lengths of pipe between the temperature measurement positions, the unit connections and the unit casing shall be insulated with at least40mm thickness of insulating material having a thermal conductivity not exceeding0.06W/m C.
