17.200.10 热、量热学 标准查询与下载

DIN EN 1434-2 Berichtigung 1:2008 量热计.第2部分:构造要求.勘误表DIN EN 1434-2-2007-05

Heat meters - Part 2: Constructional requirements; German version EN 1434-2:2007, Corrigenda to DIN EN 1434-2:2007-05; German version EN 1434-2:2007/AC:2007

PD CR 13582-1999 热电偶装置.一些关于热电偶选择，安装和操作指南

A heat meter is composed of three parts, a flow sensor, a temperature sensor pair and a calculator. The calculator is a unit which calculates volumes and energy consumption using the values from the temperature sensors and the flow sensor. The most common type of temperature sensor is a resistance thermometer of platinum type Pt 100, Pt 500 or Pt 1000. The sensors measure the temperature difference between the incoming and outgoing liquid . The flow sensor is probably the most troublesome assembly of the heat meter. Despite an accuracy requirement of only 4-10% it is very easy to fall outside these limits. In order to counter these effects as far as possible, there follows a summary of the various types of flow sensor and their advantages and disadvantages. The sizing of meters to match their required duty frequently turns out to have been incorrectly estimated when the heating plant commences operation. In most cases heat meters that are too large for their eventual duty are specified and accuracy at low load suffers as a result. Whilst this paper will give some guidance on essentials, it is felt that more information on this topic would be welcomed. Heat meter accuracies at times of rapidly changing heat demand are unlikely to be high. Whilst at times of low demand the effect of meter inaccuracy in terms of lost revenue is likely to be small, rapid changes involving high demands on the network may possibly have important implications in lost revenue if meter reaction to rapid changes is slow. Research into the subject seems to have been largely neglected so far. The most commonly used types of flow sensors have been listed in Annex B and the effect on accuracy of different types of disturbances for each of the listed types of flow sensors are considered. There is little information on the effects of flow and flow disturbances on the service life of the flow sensor, as distinct from its effect on the sensor’s accuracy. To be welcomed, therefore, is the long term research project on this topic initiated in Germany which should result in useful data.

Heat meter installation. Some guidelines for selecting, installation and operation of heat meters

DS/EN 1434-4/AC:2008 热量表 第4部分：型式认可测试

This European Standard specifies pattern approval tests applies to heat meters, that is to instruments intended for measur¬ing the heat which, in a heat-exchange circuit, is absorbed or given up by a liquid called the heat-conveying liquid. The heat meter indicates the quantity of heat in legal units.Electrical safety requirements are not covered by this European Standard.Pressure safety requirements are not covered by this European Standard.Surface mounted temperature sensors are not covered by this European Standard.

Heat meters - Part 4: Pattern approval tests

ASTM E598-08 用瞬变零点量热器测量高能环境的超级传热速率的标准试验方法

The purpose of this test method is to measure extremely high heat-transfer rates to a body immersed in either a static environment or in a high velocity fluid stream. This is usually accomplished while preserving the structural integrity of the measurement device for multiple exposures during the measurement period. Heat-transfer rates ranging up to 2.84 × 102 MW/m2 (2.5 × 104 Btu/ft2-sec) (7) have been measured using null-point calorimeters. Use of copper null-point calorimeters provides a measuring system with good response time and maximum run time to sensor burnout (or ablation). Null-point calorimeters are normally made with sensor body diameters of 2.36 mm (0.093 in.) press-fitted into the nose of an axisymmetric model. Sources of error involving the null-point calorimeter in high heat-flux measurement applications are extensively discussed in Refs (3-7). In particular, it has been shown both analytically and experimentally that the thickness of the copper above the null-point cavity is critical. If the thickness is too great, the time response of the instrument will not be fast enough to pick up important flow characteristics. On the other hand, if the thickness is too small, the null-point calorimeter will indicate significantly larger (and time dependent) values than the input or incident heat flux. Therefore, all null-point calorimeters should be experimentally checked for proper time response and calibration before they are used. Although a calibration apparatus is not very difficult or expensive to fabricate, there is only one known system presently in existence (6 and 7). The design of null-point calorimeters can be accomplished from the data in this documentation. However, fabrication of these sensors is a difficult task. Since there is not presently a significant market for null-point calorimeters, commercial sources of these sensors are few. Fabrication details are generally regarded as proprietary information. Some users have developed methods to fabricate their own sensors (7). It is generally recommended that the customer should request the supplier to provide both transient experimental time response and calibration data with each null-point calorimeter. Otherwise, the end user cannot assume the sensor will give accurate results. Interpretation of results from null-point calorimeters will, in general, be the same as for other heat-flux sensors operating on the semi-infinite solid principle such as coaxial surface thermocouples and platinum thin-film gages. That is, the effects of surface chemical reactions, gradients in the local flow and energy fields, thermal radiation, and model alignment relative to the flow field vector will produce the same qualitative results as would be experienced with other types of heat flux sensors. In addition, signal conditioning and data processing can significantly influence the interpretation of null-point calorimeter data.1.1 This test method covers the measurement of the heat-transfer rate or the heat flux to the surface of a solid body (test sample) using the measured transient temperature rise of a thermocouple located at the null point of a calorimeter that is installed in the body and is configured to simulate a semi-infinite solid. By definition the null point is a unique position on the axial centerline of a disturbed body which experiences the same transient temperature history as that on the surface of a solid body in the absence of the physical disturbance (hole) for the same heat-flux input. 1.2 Null-point calorimeters have been used to measure high convective or radiant heat-transfer rates to bodies immersed in both flowing and static environme......

Standard Test Method for Measuring Extreme Heat-Transfer Rates from High-Energy Environments Using a Transient, Null-Point Calorimeter

ASTM E2070-08 用等温法的差示扫描量热法测定动力系数的标准试验

This test method is useful for research and development, quality assurance, regulatory compliance and specification acceptance purposes. The determination of the order of a chemical reaction or transformation at specific temperatures or time conditions is beyond the scope of this test method. The activation energy results obtained by this method may be compared with those obtained from Test Method E 698 for nth order and autocatalytic reactions. Activation energy, pre-exponential factor and reaction order results by this method may be compared to those for Test Method E 2041 for nth order reactions.1.1 Test Method A determines kinetic parameters for activation energy, pre-exponential factor and reaction order using differential scanning calorimetry from a series of isothermal experiments over a small (8764; 10 K) temperature range. This treatment is applicable to low nth order reactions and to autocatalyzed reactions such as thermoset curing or pyrotechnic reactions and crystallization transformations in the temperature range from 300 to 900 K (30 to 630 °C). This test method is applicable only to these types of exothermic reactions when the thermal curves do not exhibit shoulders, discontinuities or shifts in baseline. 1.2 Test Method B also determines the activation energy of a set of time-to-event and isothermal temperature data generated by this or other procedures. 1.3 Test Method C determines the activation energy and initial heat flow from a series of isothermal experiments over a small temperature range. Because this approach only determines kinetic parameter of activation energy, no knowledge of the kinetic model is required. Therefore it is considered to be “model free”. This approach is broadly applicable to a variety of complicated reactions including those not well understood. 1.4 SI units are the standard. 1.5 This test method is similar but not equivalent to ISO 11357, Part 5, and provides more information than the ISO standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 8.

Standard Test Method for Kinetic Parameters by Differential Scanning Calorimetry Using Isothermal Methods

ASTM E341-08 用能量平衡法测量等离子体电弧气体焓的标准实施规程

The purpose of this practice is to measure the total or stagnation gas enthalpy of a plasma-arc gas stream in which nonreactive gases are heated by passage through an electrical discharge device during calibration tests of the system. The plasma arc represents one heat source for determining the performance of high temperature materials under simulated hyperthermal conditions. As such the total or stagnation enthalpy is one of the important parameters for correlating the behavior of ablation materials. The most direct method for obtaining a measure of total enthalpy, and one which can be performed simultaneously with each material test, if desired, is to perform an energy balance on the arc chamber. In addition, in making the energy balance, accurate measurements are needed since the efficiencies of some plasma generators are low (as low as 15 to 20 % or less in which case the enthalpy depends upon the difference of two quantities of nearly equal magnitude). Therefore, the accuracy of the measurements of the primary variables must be high, all energy losses must be correctly taken into account, and steady-state conditions must exist both in plasma performance and fluid flow. In particular it is noted that total enthalpy as determined by the energy balance technique is most useful if the plasma generator design minimizes coring effects. If nonuniformity exists the enthalpy determined by energy balance gives only the average for the entire plasma stream, whereas the local enthalpy experienced by a model in the core of the stream may be much higher. More precise methods are needed to measure local variations in total enthalpy.1.1 This practice covers the measurement of total gas enthalpy of an electric-arc-heated gas stream by means of an overall system energy balance. This is sometimes referred to as a bulk enthalpy and represents an average energy content of the test stream which may differ from local values in the test stream. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Standard Practice for Measuring Plasma Arc Gas Enthalpy by Energy Balance

ASTM E458-08 烧蚀的热标准试验方法

General8212;The heat of ablation provides a measure of the ability of a material to serve as a heat protection element in a severe thermal environment. The parameter is a function of both the material and the environment to which it is subjected. It is therefore required that laboratory measurements of heat of ablation simulate the service environment as closely as possible. Some of the parameters affecting the heat of ablation are pressure, gas composition, heat transfer rate, mode of heat transfer, and gas enthalpy. As laboratory duplication of all parameters is usually difficult, the user of the data should consider the differences between the service and the test environments. Screening tests of various materials under simulated use conditions may be quite valuable even if all the service environmental parameters are not available. These tests are useful in material selection studies, materials development work, and many other areas. Steady-State Conditions8212;The nature of the definition of heat of ablation requires steady-state conditions. Variances from steady-state may be required in certain circumstances; however, it must be realized that transient phenomena make the values obtained functions of the test duration and therefore make material comparisons difficult. Temperature Requirements8212;In a steady-state condition, the temperature propagation into the material will move at the same velocity as the gas-ablation surface interface. A constant distance is maintained between the ablation surface and the isotherm representing the temperature front. Under steady-state ablation the mass loss and length change are linearly related. where: t= test time, s, ρo= virgin material density, kg/m3, δL= change in length or ablation depth, m, ρc= char density, kg/m3, and δc= char depth, m.This relationship may be used to verify the existence of steady-state ablation in the tests of charring ablators. Exposure Time Requirements8212;The exposure time required to achieve steady-state may be determined experimentally by the use of multiple models by plotting the total mass loss as a function of the exposure time. The point at which the curve departs significantly from linearity is the minimum exposure time required for steady-state ablation to be established. Cases exist, however, in the area of very high heating rates and high shear where this type of test for steady-state may not be possible. 1.1 This test method covers determination of the heat of ablation of materials subjected to thermal environments requiring the use of ablation as an energy dissipation process. Three concepts of the parameter are described and defined: cold wall, effective, and thermochemical heat of ab......

Standard Test Method for Heat of Ablation

ASTM E928-08 用差分扫描量热法测定克分子杂质百分率的标准试验方法

The melting temperature range of a compound broadens as the impurity level rises. This phenomenon is described approximately by the van't Hoff equation for melting point depressions. Measuring and recording the instantaneous heat flow into the specimen as a function of temperature during such a melting process is a practical way for the generation of data suitable for analysis by the van't Hoff equation. The results obtained include: sample purity (expressed as mole percent); enthalpy of fusion (expressed as joules per mole); and the melting temperature (expressed in Kelvin) of the pure form of the major component. Generally, the repeatability of this test method decreases as the purity level decreases. This test method is ordinarily considered unreliable when the purity level of the major component of the mixture is less than 98.5 mol % or when the incremental enthalpy correction (c) exceeds 20 % of the original detected enthalpy of fusion. This method is used for quality control, specification acceptance, and research.1.1 This method describes the determination of purity of materials greater than 98.5 mole percent purity using differential scanning calorimetry and the van't Hoff equation. 1.2 This test method is applicable to thermally stable compounds with well-defined melting temperatures. 1.3 Determination of purity by this test method is only applicable when the impurity dissolves in the melt and is insoluble in the crystal. 1.4 SI values are the standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 1.6 There is no ISO method equivalent to this method.

Standard Test Method for Determination of Purity by Differential Scanning Calorimetry

EN 1434-3:2008 量热计.第3部分:数据交换和接口

This European Standard applies to heat meters, that is to instruments intended for measuring the heat which, in a heat-exchange circuit, is absorbed or given up by a liquid called the energy-conveying liquid. The meter indicates heat in legal units. Electrical safety requirements are not covered byThis standard. Part 3 specifies the data exchange between a meter and a readout device (POINT / POINT communication). For these applications using the optical readout head, the EN 62056-21 protocol is recommended. For direct or remote local readout of a single or a few meters via a battery driven readout device, the physical layer of EN 13757-6 (local bus) is recommended. For bigger networks with up to 250 meters, a master unit with AC mains supply according to EN 13757-2 is necessary to control the M-Bus. For these applications the physical and link layer of EN 13757-2 and the application layer of EN 13757-3 is required. For wireless meter communications, EN 13757-4 describes several alternatives of walk/drive-by readout via a mobile station or by using stationary receivers or a network. Both unidirectionally and bidirectionally transmitting meters are supported byThis standard.

Heat Meters - Part 3: Data exchange and interfaces

LST EN 1434-2-2007/AC-2007 热量表 第2部分：结构要求

Heat meters - Part 2: Constructional requirements

LST EN 1434-4-2007/AC-2007 热量表 第4部分：型式认可测试

Heat meters - Part 4: Pattern approval tests

NF E17-401-6:2007 量热计.第6部分:安装、调试、操作监测和维护

Heat meters - Part 6 : installation, commissioning, operational monitoring and maintenance.

NF E17-401-2:2007 量热计.第2部分:结构要求

Heat meters - Part 2 : constructional requirements.

NF E17-401-4:2007 量热计.第4部分:模式验收试验

Heat meters - Part 4 : pattern approval tests.

NF E17-401-1:2007 量热计.第1部分:一般要求

Heat meters - Part 1 : general requirements.

NF E17-401-5:2007 量热计.第5部分:初始鉴定试验

Heat meters - Part 5 : initial verification tests.

LST EN 1434-4-2007 热量表 第4部分：型式认可测试

Heat meters - Part 4: Pattern approval tests

LST EN 1434-6-2007 热量表 第6部分：安装、调试、运行监控和维护

Heat meters - Part 6: Installation, commissioning, operational monitoring and maintenance

LST EN 1434-5-2007 热量表 第5部分：初始验证测试

Heat meters - Part 5: Initial verification tests

LST EN 1434-1-2007 热量表 第1部分：一般要求

Heat meters - Part 1: General requirements