Historical development and current state of the software for hydraulic simulation and analysis of Ulaanbaatar heat networks

Historical development and current state of the software for hydraulic simulation and analysis of Ulaanbaatar heat networks

G. Bayarsaikhan, general director at Ulaanbaatar Heating Network;
L. Batmend, doctoral student at MUST EI, engineer at Ulaanbaatar Heating Network;
T. Altangerel, supervisor;
G. Otgonbayar, senior engineer of the Department;
E. Amarsanaa, Ts. Bat-Erdene, T. Sandagdorj, engineers of the Department
of Regulation, Operation, and Information Research at Ulaanbaatar Heating Network

Introduction:

When operating heat networks daily, there is a constant need to maintain heat balance in source and consumer systems, determine the prospects and growing requirements for the use of the system, conduct planned calculations and analysis, and develop technical solutions and scenarios.

This article presents the historical development and current state of the hydraulic simulation and analysis software for heat networks used in the day-to-day operation of the Ulaanbaatar district heating system.

Origin and development of the software

In 1983, the Institute of Mathematics and Digital Technologies in Ulaanbaatar calculated the heat network hydraulic conditions using the Minsk-22 and Minsk-32 electronic computers (fig. 1).

Figure 1. The first electronic computers: Minsk-22 and Minsk-32.

Minsk-22 and 32 were used for the preparation, calculation, and processing of various programs by the engineers of the Buro of Energy, Fuel, and Mining Industry, Research Institute of Mathematics, professors at the Polytechnic Institute, and employees of other departments (fig. 2).

Figure 2. Scheme and journal for calculating heat loads in 1983.

Figure 3. Scheme and journal for calculating heat loads in 1997. /Technical report/.

In 1997, the feed lines of all buildings in Ulaanbaatar with their heating systems as well as technical characteristics and equipment data were included in the database linked to the scheme in order to be able to calculate the adjustment of the operating conditions of the city heat network using computer software.

Based on this database, the Russian modeling and analysis program DISIGR was used (Dialogue System for Hydraulic Calculations of Heat Networks; it was developed by the Siberian Energy Institute of Russia (ESI SB RAS). – Ed.)(fig. 4).

Transferring data from paper sources to the database software made it possible to perform time-consuming calculations of heat network operating conditions quickly and with high accuracy while preserving all data for subsequent reuse and development of optimal heat network operating conditions.

Figure 4. DISIGR interface

Since 1998, the LIQUID calculation program was used to calculate the operating conditions of the secondary loop – thanks to the successful implementation of energy efficiency projects and heat efficiency projects financed by the Asian Development Bank (fig. 5).

Figure 5. LIQUID interface

In 2003, Denmark and Finland began to study and implement the Termis program, which is used to design heat network management systems and is also very convenient for everyday process stages of operational management (fig. 6).

Figure 6. Termis interface

The advantage of the Termis program over other software of the time was that it was directly connected to the heat network monitoring and control system, and the calculated value could be used directly to compare the results with the actual parameters and make conclusions and adjustments.

However, without a group control point, it was impossible to create double-loop networks with different temperature schedules. Consequently, it was not possible to create a single model of mains and district systems (after the central heating station), as well as a model of four-pipe networks.

The implementation of Termis was also hindered by the fact that only one person was allowed to perform calculations.

In 2012, the specialists of Ulaanbaatar Heating Network attended courses on ZuluThermo 7.0 software, which described the experience and results of the successful implementation of the program in heat supply companies. After that, it was decided to make ZuluThermo the basis for hydraulic calculations of the city’s heat networks (fig. 7).

Figure 7. ZuluThermo 7.0 interface

In 2017, the software for heat network hydraulic calculations was updated to ZuluTermo 8.0, which included many improvements (fig. 8).

Figure 8. ZuluThermo 8.0 interface

As demonstrated, it is possible to trace the stages of development of the digital model of Ulaanbaatar's heat networks from the first computations to modern complex software systems (table 1).

Table 1. Software for hydraulic simulation modeling and analysis

Date	Development and completed work
1997	Implemented DISIGR (Interactive System of Heat Network Hydraulic Calculations).
1998-2003	Implemented LIQUID software.
2003	Implemented Termis software.
2012-2013	Implemented ZuluThermo 7.0 software. Developed the computational model of the Ulaanbaatar district heating system.
2015	Began to create local models of heat networks for 21 aimags and cities in Mongolia. Began to use the database for mode calculations and research.
2017	Implemented ZuluThermo 8.0 software. Ulaanbaatar's heat supply network was divided into more than 600 sections and presented in an A3 size schematic map.
2019	The Ulaanbaatar city model was improved by Politerm engineers, and mechanical operations were automated at the program level using VBScript macros. The ZuluThermo model was integrated with the E-Heat+Portal heating substation photo database.
2020	Combined diagrams of local heat networks of aimags in Mongolia and Ulaanbaatar with data on terrain and elevation (fig. 9). Combined diagrams of local heat networks of aimags in Mongolia and Ulaanbaatar with satellite images (fig. 10). At the software level, it became possible to automatically separate all consumers by central heating station and heat exchange center.
2021	The ZuluThermo software was successfully integrated with the database of the E-Heat+Portal systems used by the company in its day-to-day operations.
2022	Added, implemented, and began to use additional calculation modules: Calculation of the required source temperature Heat network reliability analysis Reserve network capacity calculations

Figure 9. Digital terrain in the Ulaanbaatar area.

Figure 10. Satellite images of Ulaanbaatar.

Current state of the simulation and analysis software

Heat networks, equipment at central heating stations, customer building, and heating inputs are regularly updated with their database being enriched; human involvement is minimized, autonomous systems are being developed and integrated with the ZuluThermo software for сalculating operating conditions, and research is also being carried out.

As of 2022, in Mongolia, ZuluThermo is regularly and officially used by Ulaanbaatar Heating Network, Housing and Communal Administration, National Dispatch Center, and Margad Erchim (fig. 11, 12).

Figure 11. ZuluThermo 8.0 schematic map

Figure 12. 3D models of the buildings were created using data on the number of floors.

Main projects and calculations of operating conditions performed using ZuluThermo 8.0:

• calculation and study of the uniform load distribution of the Almagan heat network;
• calculation of the Bayankhoshuu substation connection to the district heating system;
• hydraulic calculations and study of heat supply networks in the cities of Khovd, Dundgovi, Govi-Altai, Gobi-Sümber, Sükhbaatar, Uvs, Bulgan, Dornogovi, Selenge, Khövsgöl, Baganuur, Sainshand and Nalaikh;
• calculation of the Denjiin 1000 substation connection to the district heating system;
• calculation of the connection to the CHP-4 15th mainline network;
• calculation of the operating conditions of the Zamiin-Uud thermal power plants;
• calculation of the connection to the CHP-4 210 MW mainline network;
• calculation of the Tolgoit and Selbe substation connection to the district heating system;
• calculation of the connection to the 5-12 mainline network;
• calculation of the connection to the CHP-4 13th mainline of the lower point;
• calculation of heat sources for peak hours /4 locations/;
• hydraulic calculation and analysis of the network when implementing projects scheduled for financing by the World Bank and the Asian Development Bank;
• hydraulic calculation and analysis of the network when expanding the medium pressure section of CHP-3.

Main types of calculations performed by specialists of Ulaanbaatar Heating Network using ZuluThermo:

• calculating 4-5 different operating modes of the heat network during the heating season followed by discussion and selection of the optimal option;
• calculating 4-5 different operating modes of the heat network during the summer and maintenance periods followed by discussion and selection of the optimal option;
• developing and calculating emergency operating modes of the heat network;
• calculating the central line, heat exchange center, and adjustment device /orifice/ for consumers during the heating season;
• plotting piezometric graphs, developing optimal operating conditions for pumping stations during the heating season (fig. 13);
• collecting and entering information about prospective consumers into the program, performing hydraulic calculations, and coordinating technical conditions for connection. If it is impossible to connect the required load, analyzing problem areas and developing technical solutions that facilitate the connection of new consumers;
• calculating heat balance for the heat source and distribution network;
• determining heat losses in mains systems and distribution networks.

In addition to ZuluThermo and Termis, other software products are being developed for calculating the hydraulic modes of heat networks: Fluidit (Finland), Thermos (Germany), nPro (Germany), Trimble, etc.

Figure 13. Plotting a piezometric graph inZuluThermo 8.0.

Table 2. The comparison of hydraulic calculation software.

№	Description	Termis	ZuluThermo 8.0 ZuluThermo 2021	Arcgis VertiGis UT
1	Integration with SCADA system	+	+ ZuluOPC	+
2	Piezometric graph	+	+	-
3	Types of CHS circuits	1	37 types	1
4	Types of heating substation circuits	1	46 types	1
5	Calculation of head losses in pipes	+	+	+
6	Calculation of heat losses in pipes	-	+	+
7	Automatic selection of diameters	+	+	+
8	Automatic calibration of hydraulic losses, heat losses, leaks	-	hydraulic losses and leaks	-
9	Calculation of permissible flow capacity in network pipes	-	+	-
10	Automatic leak detection in networks	-	+	-
11	Terrain elevation	-	+	+
12	Connection to satellite images	+	+	+
13	Schematic map	+	+	+
14	Macros and automation	+	+	-
15	Working with Shapefile*	+	+	+
16	Working with Dwg, Dxf**	+	+	+
17	Updates	2-3 years	every month	every year

Notes
*Shapefile – a geospatial vector file format, essentially the standard for data exchange between geoinformation systems;

Conclusion

To further improve the operation processes, we have successfully implemented the ZuluThermo software – the program for modeling hydraulic modes of heat networks based on a geospatial information system. The complex digital model of heat networks includes information about in-line equipment, equipment at central and individual district heating substations, and heating sources, and is connected to a single centralized district heating database based on the Portal.dulaan.mn data management system.

Using the Portal system and connecting to the Zulu digital model, users can exchange basic data for calculations, eliminate duplication and discrepancies in data, reduce the number of manual mechanical operations, reducing the time spent on surveys and calculations in the process, and improve qualitative results.

In the future, we plan to use the new functions of ZuluThermo software extensively: calculate heat losses, analyze network reliability, estimate reserve network capacity, use the ZuluGISMobile app, improve schematic maps, automate mechanical data input operations, develop a data integration control panel, and implement ZuluThermo2021.

Source

• РосТепло.ru / Технические статьи / Тепловые сети / Программное обеспечение для расчёта гидравлического режима ...

Literature

1. Monakhov G.V. «Modeling control modes of heat networks» M.: Energoatomizdat, 1995.
2. Politerm website. URL:https://www.politerm.com/.
3. Energy & Engineering of Mongolia, p. 50, 2021-10 (212).

Ulaanbaatar Heating Network expresses its appreciation and gratitude to Politerm for the effective work throughout our cooperation. In addition to high professionalism, creativity in work, and understanding of the customer's needs, we would especially like to note the ability of the specialists to see the desired outcomes for the client. We recommend Politerm as a reliable partner!

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