1、 热量表选型 Heat Meter Selection 2011年 12月 徐竹 热量表产品经理 兰吉尔仪表系统(珠海)有限公司 电 话 : 010 -83915250-88 邮件 : 热量表的选型关键因素 Key selection point for Heat Meter 精度 accuracy 常用流量及测量范围 permanent flow-rate ( qp) 温度: 4秒 /60秒 measuring cycle: flow 4s; temperature 4s/60s 当 流量快速增加 ( 30% ) ,温度测量与流量测量同步 4秒 当最近的 2分钟 内温度变化 低于 1K时,
2、恢复 60秒周期测量温度。 A rapid increase of the flow ( 30% ), T230 changes the temperature measuring cycle to the appropriate flow rate-measuring cycle (4 sec.). temperature difference changes less than 1K resp. latest after 2 min, switched to the longer measuring cycle. 电池寿命支持每天 30次( battery support 30 times
3、 per day) 按照常用流量选择,宽测量范围的热量表 Choose HM by qp and choose wide measurement range 量程比:热量表常用流量与最小流量之比 measurement rate qp : qi 100: 1 过载能力:最大流量与常用流量之比 overload qs : qp 2:1 启动流量:开始计量的起始流量 star q起动 2 x qp q起始 qi qp qs=2qp 1 : 500 或 1 : 1000 流量 1 : 100 1 : 2 如 : qp 1.5 m/h 3 L/h 15 L/h 1,500 L/h 3,000 L/h
4、为什么按照常用流量选择热量表? Why need to choose HM according to qp ? 热表将工作在常用流量附近,精度最好,运行最稳定。 HM will work around qp. It will be good accuracy. 降低投资成本。按常用流量选择热表,口径通常较小。 Reduce the investment costs due to smaller size. 选用压损小的热表可降低变径带来的压损影响。 Choose lower pressure loss HM, reduce the bed influence of necking。 一款超声波
5、热量表典型的误差曲线 L+G T230 Heat Meter Typical Accuracy 说明: T230 典型测量误差曲线 EN 1434 标准等级 2 为什么需要考虑热量表的测量范围? Why need to concern HM measurement range 在中国,很多情况都是大口径,运行在小流量 in China, most of time, running in smaller flow 小流量的准确计量非常重要 smaller flow in high accuracy is very important 常用流量相同时,量程比大则最小流量更低 in same qp,
6、 large rate will get smaller qi 宽量程比的热量表能带来的好处 Benefit of Wide Measurement range 宽的量程比可以减少表的规格 wide measurement rate reduce the meter type 表的规格减少,便于维修、更换和降低库存 few meter type will be helpful for maintain and reduce the storage 在小流量下,可以准确计量,实现高精度 large measurement rate get smaller flow in higher accur
7、acy 更小起动流量,防止跑冒滴漏和不正当用热 smaller start flow could reduce leak & improper use heat 高过载能力适应增容需要 higher overload could meet the further increased capacity 选型举例: e.g. 按照 0.5m3/h流量,可供热 100m2计算 100m2的住宅,通常管路系统设计为: DN20或 DN25 DN20 qp =1.5m3/h 或 2.5m3/h DN25 qp =3.5m3/h 或 6.0m3/h 如果选择 DN25口径的热表: 0.5m3/h只是常用流
8、量的 1/7 常年工作在小流量附近,计量误差大 建议选择: DN20 1.5m3/h 的热表 0.5m3/h could heat 100m2 100m2 apartment, pipe system design as DN20 or DN25 If use DN25 HM, 0.5m3/h = 1/7 * qp Work in smaller area of flow, the accuracy will be not good. selection suggestion: Heat Meter with DN20 qp=1.5m3/h 低压损的热量表 Lower pressure los
9、s Heat Meter 压损:在给定流量下,热量表所造成的压力降低值 pressure loss 压损和流量有关 it is related with qp 压损与流量管内超声波信号反射通道的设计相关 it is depend on the flow tube design for ultrasonic signal refection cancel 期望越小越好 expect pressure loss is as smaller as possible 热表的安装位置 Installation place 关注热表是否需要前后直管段?是否允许垂直安装或倾斜安装? required str
10、aight pipe before and after? allow install HM in vertical or inclined? 安装环境是否潮湿,高温? higher humidity and high temperature? 周围是否有强磁场或泵? Any Strong magnetic field or pump 注意热量表的安装供回水位置及水流方向 Heat meter install in flow or return and direction 区分温度探头的供回水位置 temperature sensor installed in flow or return 长期
11、稳定的热量表 Long term use of Heat Meter 减少结垢并延缓结垢 Reduce the soiling chance and delay soiling 处理结垢影响 Handle the soiling effect 耐久性测试认证长寿命 Durability test to certificate long term use 长期稳定的热量表 Long term use of Heat Meter 减少并延缓结垢: Reduce the soiling chance and delay soiling - 改善水质 热力公司 improve water QA by
12、heating company - 改善表的材质 表制造商 use the new material by manufacture - 改善表的加工工艺 表制造商 improve production processing by manufacture 长期稳定的热量表 Long term use of Heat Meter 处理结垢影响 Handle the soiling effect - 热表随时检测超声波信号幅度 integrated design, monitoring the ultrasonic - 当超声波信号减弱时,自动增强信号强度 Automatic amplificati
13、on of ultrasonic signal - 内螺纹 DuraSurface专利设计,降低内壁结垢的影响 DuraSurface patented design, negligible soiling impact 长期稳定的热量表 Long term use of Heat Meter 长期稳定的热量表 Long term use of Heat Meter 耐久性测试认证长寿命 Durability test to certificate long term use 欧洲权威机构 PTB组织发布新的耐久性测试方法 PTB issued the new Durability test
14、超声波表更需要测试不同温度下的流量变化,以及温度变化对超声波表的影响 Ultrasonic meter should test the flow in different temperature and the inference of temperature change 兰吉尔热量表经过 4000循环周期测试结果 L+G T230 Heat Meter Typical Pressure Loss 选择一款好的热量表可以让你 放心, 安心, 省心! Choose a good heat meter make you Rest assure Peace of mind 谢谢! 客户服务热线:( 010) 83915250 热表服务电邮: