eQUEST模拟四管制地源热泵

• 1、地源热泵只做热源，冷源由其他的冷机供应

• 2、带热回收的地源热泵

• 3、四管制的地源热泵

• 4、地源热泵+蓄冷+蓄热

上述单独四种情况使用eQUEST提供的两管制热泵模型都无法解决。

近期我就遇到了一个项目，包含了2、3、4三种情形。该项目采用3台四管制地源热泵机组，2台带热回收的热泵机组，并且还使用了蓄冷和蓄热技术。系统设计相当复杂。以前的经验，对于这些情形我采用制冷模型和制热模型分开模拟的方式，也就是一个模型只模拟制冷工况，另一个模型只模拟供热工况，但是显然模拟过程很繁杂，结果数据也需要进行后处理，如果递交LEED模拟，还需要把你的模拟方法以及数据后处理的方法做很详细的说明。所以我就就开始研究看看有没有一种更简便的方法模拟，之前制冷制热模型分开的思路是：在制冷模型中采用冷机模拟地源热泵的制冷工况，然后在制热模型中使用热泵机组供热。但是由于热泵机组只能连接2-pipe类型的管路，所以导致制冷制热无法在同一个模型中。如果存在一个热泵机组可以连接热水管路（Hot water loop），那么制冷模型和制热模型就可以在一个模型中。于是我通过查阅eQUEST帮助文档注意到loop to loop heat pump系统。描述如下：

This chiller is attached to a both a chilled-water loop and a hot-water loop (Figure 30). The chiller actively supplies cooling and/or heating to the two loops. A lake/well water loop supplies the necessary heat balance via two heat-exchangers in series with the evaporator and condenser loops. 

The chiller requires both evaporator and hot-water pumps, and these pumps must be able to operate independently of the chilled and hot-water loops. For this reason, the chilled-water and hot-water loops must have their own pumps, in addition to the chiller pumps. The evaporator and condenser pumps operate in a constant-flow mode, variable-flow operation is not permitted.  However, the circulation-loop chilled-water and hot-water loop pumps may be either constant-flow or variable-flow.

The lake/well-water loop (condenser loop) interfaces with the two heat-exchangers. It can be pumped identically as described for other chillers. Most commonly, the lake/well loop will have its own pump. However, the chiller may have a condenser pump in addition to, or in lieu of, the well pump. If the condenser pump is in lieu of a pump directly attached to the lake/well loop, then it will power the loop. Otherwise it will act only to overcome the head of the chiller’s heat-exchangers. The condenser flow may be modulated using either two-way or three-way valves, the default is two-way, resulting in variable –volume condenser flow.

具体操作如下（以我上面提到的项目为案例）：

1、建立3台离心冷机和2台热回收冷机，用于模拟地源热泵的制冷工况。并且用Thermal storage(Cold water tank) 模拟蓄冷系统。同时将热回收的loop连接到生活热水，eQUEST界面如下：

2、创建4台loop to loop heat pump，这里并应该是5台，但是由于一个loop只能最大连接10台设备，所以这里把CH4和CH5合并。并用Thermal storage(Hot water tank) 模拟蓄热系统。注意：由于loop to loop Heat pump需要连接制冷和制热都连接管路，因此我们这里虽然模拟的制热工况，但是制冷管路也要连接，等下我们使用设备控制器保证这个热泵不会制冷。

3.创建设备控制器，确保只有冷机进行制冷，热泵不制冷。