我使用hammmer软件对水泵的开机进行了模拟。模拟是这样，水泵在第5s开始开机。
出水闸门（TCV，初始状态为关闭100%）在第7.5S开闸,开闸的总时间为40s
开机模拟的水泵出水侧的水力坡度曲线如下：
开机模拟的水泵进水侧的水力坡度曲线如下：
这种模拟水泵的出水侧出现了压力波动：水泵出水先是增大然后减小，然后又增大后减小。进水侧也出现了类似情况。
水泵的实际扬程要比设计工况高几米，请问这个是否正常，怎么解释这种现象，符合实际开机过程吗？
你好，
这可能与您计算泵启动事件的目标水头和流量的方式有关。
在对泵启动事件进行建模时，您要做的第一步是打开泵并计算稳态运行，以查看模拟结束时泵头和流量应该是什么。您需要确保TCV也已打开，并且需要查看计算出的排放系数是多少。
这是因为如果您使用TCV的设置在泵启动事件期间与目标头和流量所基于的稳态运行相比不同，则这将对结果产生影响。
此链接包含有关此信息的信息，包括有关模型中存在活动阀时应采取的措施的说明：https://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/3276/modeling-a-pump-start-up-transient-event-in-hammer-v8i-and-connect-edition
如果你有问题，请告诉我们。
Regards,
Scott
model.rar我把相关文件发布
Answer Verified By: 邹 凯宁
中文版我的回答：
您看到的压力变化（增加，减少，增加，再次减少）可能主要是由于与同时打开的阀门的相互作用。 当泵打开时，阀门开始打开，阀门开启区域增加的速率取决于TCV的“阀门类型”。 将“圆形门”设置为TCV“阀门类型”，当阀门首次开启时，开口面积/流量的初始增加相对较大，如本文所示（英文）：
https://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/15981/valve-type-field-assumptions-and-use-with-a-tcv
在泵达到全速后，阀门仍然打开，因此在泵最终稳定在其最终工作点之前，可以看到一些波动。 此时，泵上游侧的水力等级在下游侧约5.8米和约20.8米处，总扬程为15米，流量为38立方公尺/秒。 这与泵的“标称”工作点非常接近。 有一些原因导致瞬态模拟中的最终泵工作点可能与下文所述的预期工作点（英文）不匹配，但在您的情况下似乎相当匹配（但请参见项目＃ 关于“标称”头部和流量设置，下面有4个）
https://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/3276/modeling-a-pump-start-up-transient-event-in-hammer-v8i-and-connect-edition
此外，在瞬态模拟过程中泵的行为有时会对您在“泵定义”的“瞬态”选项卡中选择的“特定速度”敏感。 您选择了SI = 117选项，这是不经常使用的选项。 您可能需要确认根据以下文章（英文）中的公式选择最接近的特定速度：
https://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/20042/estimating-the-specific-speed-of-a-pump-or-turbine
作为说明灵敏度的示例，如果您将特定速度更改为SI = 123选项（非常接近SI-117选项），您将看到不同的瞬态结果（只有一个增加/减少，并且附近的条件更平滑） 模拟结束），表明可能存在某种特定速度的模型不稳定性（四象限曲线）。
看着你的模特，我发现了一些问题：
1）TCV模式设置为开始关闭然后打开，但初始状态显示它已打开。这不会产生很大的差异，因为泵最初也是关闭的，但我建议将“系数类型”更改为“阀门特性曲线”，然后将“相对闭合（初始）”设置为99.99％。
2）在瞬态计算选项中，进行以下更改：
- 将“报告期间”设置为较小的值，例如10 - 将“生成动画数据”设置为“true”。这将使您能够为配置文件路径设置动画，以便在瞬态事件发生时查看发生的情况。
3）完整型材长度仅约60米 - 这是正确/准确的吗？这似乎是一个非常小的规模。
4）泵的“流量（标称值）”和“扬程（标称值）”可能不正确。如果我将泵初始状态设置为On并且TCV初始状态设置为无效（完全打开），则泵工作点为15.04 m和36.7 m ^ 3 / s。但是，您已将标称扬程和流场分别设置为14.5 m和38 m ^ 3 / s。
5）泵的“控制变量”设置为“速度”，这意味着您分配给泵的模式直接控制叶轮速度。因此，模式使泵在0到10秒之间从零到全速。您需要确保泵实际需要5秒才能旋转到全速。否则，您可以将“控制变量”设置为“扭矩”，以更接近地模拟“打开”泵，以便泵特性和系统条件将决定泵达到全速所需的时间。在这些文章中查看更多内容（英文）：
https://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/28295/how-does-pump-inertia-effect-the-pump-calculations-during-a-transient-simulation
https://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/31834/calculating-nominal-torque-for-a-transient-pump-startup-or-variable-speed
English version of my answer:
The pressure variations (increase, reduce, increase, reduce again) that you see are likely mainly due to the interaction with the valve that is opening at the same time. As the pump is turning on, the valve is starting to open, and the rate at which the open area of the valve increases is based on the "valve type" of the TCV. With the "circular gate" set as the TCV "valve type", there is a relatively large initial increase in opening area/flow as the valve first starts to open, as seen in this article (in English):
After the pump reaches full speed, the valve is still opening, so some fluctuation is seen, before the pump eventually settles on its final operating point. At that point, the hydraulic grade on the upstream side of the pump settles at around 5.8 m and around 20.8 m on the downstream side, for a total head of 15 m, at a flow of 38 m^3/s. This matches very close to the "nominal" operating point set for your pump. There are some reasons for why the final pump operating point in the transient simulation may not match the expected operating point as identified in the below article (in English), but it seems to match up quite well in your case (though, see item #4 below regarding the "nominal" head and flow setting)
Furthermore, the behavior of the pump during the transient simulation can sometimes be sensitive to the Specific Speed that you choose in the Transient tab of the Pump Definition. You have chosen the SI=117 option, which is not often used. You may want to confirm that the closest Specific Speed is selected based on the equation in the following article (in English):
As an example to illustrate the sensitivity, if you change the Specific Speed to the SI=123 option (very close to the SI-117 option), you will see a different transient result (only one increase/decrease, and smoother conditions near the end of the simulation), indicating that there might be some model instability with that particular specific speed (four-quadrant curve).
While looking at your model I also noticed a few problems:
1) The TCV pattern is set to start closed and then open, but the initial status shows that it is open. This does not make a large difference since the pump is also initially off, but I would suggest changing the "coefficient type" to "valve characteristics curve", then set the "relative closure (initial)" to 99.99%.
2) In the transient calculation options, make the following changes:
- Set the "report period" to something smaller such as 10- Set "generate animation data" to "true". This will enable you to animate the profile path so you can see what is happening as the transient event occurs.
3) The full profile length is only about 60 m long - is this correct/accurate? It seems to be a very small scale.
4) The pump's "flow (nominal)" and "head (nominal)" may not be correct. If I set the pump initial status to On and the TCV initial status to inactive (fully open), the pump operating point is 15.04 m and 36.7 m^3/s. However you have set the nominal head and flow field to 14.5 m and 38 m^3/s, respectively.
5) The pump's "control variable" is set to "speed", which means the pattern you assigned to the pump is directly controlling the impeller speed. So, the pattern has the pump go from zero to full speed between 5 seconds and 10 seconds. You will need to make sure that the pump would actually take 5 seconds to spin up to full speed. Otherwise, you can set the "control variable" to "torque", to more closely model "turning on" the pump, so that the pump characteristics and system conditions will determine how long it takes for the pump to reach full speed. See more in these articles (in English):
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.
THANKS A LOT!