ALONE. small scale solar cooling device Project No TREN FP7EN Project No TREN/FP7EN/ ALONE. small scale solar cooling device

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1 Project No TREN/FP7EN/ ALONE small scale solar cooling device Collaborative Project Small or Medium-scale Focused Research Project DELIVERABLE D3.3 Start date of the project: October 2008, Duration: 48 months EURAC Co-Ordinator of the Responsible Beneficiary: Roberto Fedrizzi Authors: Anton Soppelsa, Roberto Fedrizzi Status: Final Co-Ordinator of the Project: Maurizio De Lucia 1

2 Summary 1. Introduction Components installation Pipings connections Energy Box System finalization

3 1. Introduction ALONE The aim of this document is to comment the installation phase of the Bronzolo solar heating and cooling system. The report, enriched by the pictures taken in the process, discusses the installation of the main components of the system: solar collectors, absorption chiller, dry cooler, hot storage, piping and Energy Box (EB), which comprises the electronic equipment for its control. Moreover, pictures and final remarks regarding the status of the solar system right after the conclusion of its installation can be found in the last section. 2. Components installation All the main components of the solar system, with the exception of the EB, were installed during November The solar collectors, or solar field, were placed on the rooftop, together with the dry cooler. The storage was placed in a dedicated room adjacent to garage, while the sorption chiller was installed inside the technical room in the basement where the pre-existing heating and domestic hot water (DHW) system was already in place. Picture 1 Installation of the solar collectors Picture 2 Installation of the solar collectors The collectors were arranged in 6 groups of 3, for a total of 18 panels and 40 m 2 of capturing surface. The model of the installed collectors, manufactured by the Riello company, is CSV25. This type of solar collector is constituted by 14 double wall glass evacuated tubes, each of which contains an "U" shaped copper pipe. This copper tube is connected 3

4 in series and goes through all the pipes in the collector from the first to the last one. The three collectors forming a group are also connected together in series. A detail of the connection between two collectors is shown in Picture 3. The groups of panels were instead connected in 6 parallel. After the installation and connection of the solar collectors, the solar circuit was filled with a solution of water and ethylene glycol. The use of the glycol avoids the freezing of the water during the winter season. Picture 1 and Picture 2 show how the collectors are settled on the roof, headed to the south direction. In particular, in Picture 2 it is possible to appreciate the inclination of the panels, around 30. All the panels were anchored to a concrete basement stepping from the green roof base level, visible in Picture 2 and Picture 4. Picture 3 - Junction between two collectors Picture 4 - Anchorage of the solar collectors Another important component of the system is the Dry Cooler. This component is used to reject heat from the absorption chiller which cannot be used for other purposes or rejected through the geothermal probes. The dry cooler installed in Bronzolo is produced by the Thermics company and is called Dry Cooler CTH25. This type of dry cooler is made completely of aluminum, and shows an increased exchange surface due to its plate and fins design. The kind of fans used in this dry cooler grants a low noise level and a high energy efficiency. The dry cooler was also installed over concrete basement on the roof as shown in Picture 5. 4

5 Picture 5 - Installation of the dry cooler The storage tank is shown in Picture 6. The shot shows it before application of its insulation and gives a better impression of the volume of the water it can store. The insulation makes it sensibly larger. This component is manufactured by Ratiotherm and the model installed on site goes under the name of OSKAR. This device allows to store 3000 l of water in a stratified way, to reduce the thermal losses. Picture 6 shows the inputs and outputs connections below the tank. Note that although all of them are positioned on the bottom of the storage, they emerge in different temperature zones. Properly shaped internal chambers and layers allow to minimize the convective component of the heat flux in the reservoir, maximizing the storage efficiency. Picture 6 - installation of the storage Since the installation of the solar system was actually a renovation action, the spaces available in the technical room were not suitable for the installation of such a large tank; therefore the tank was setup in the garage (adjacent to the rest of the installation) and a technical room constructed around it, by raising a wall to separate it from the garage 5

6 area. The core of the solar cooling system is the SolarChiller absorption chiller, manufactured by ClimateWell. It consists of two twin barrels where the absorption process takes place, a connection kit with valves and fittings and a control system that manages the valves and calculates various quantities of interest describing the status of the machine and of the chilling process. The sorption chiller was installed in the technical room. From Picture 7 and Picture 8 is possible to have an idea of where it is installed, close to the pellet boiler (primary heat source of the building) and the centralized air handling unit. Picture 7 - Climatewell sorption chiller Picture 8 - heat exchangers near sorption chiller Picture 8 shows the chiller from a different angle, from where two heat exchangers (blue) of the DHW circuit can be appreciated. These two heat exchangers connect solar to pre-existing DHW systems, where the pellet boiler warms up the water in a 800 liters tank (the red one in Picture 8). Finally, Picture 9 shows how the chiller was linked to the circuits using the connection kit, the 6 tubes relative to the 3 circuits mentioned above are clearly visible on the top right. The kit comprised 10 double ball electrical valves, consisting of a brass housing, balls made of chromium plated brass, O-rings in EPDM and sealing in PTFE. 6

7 Picture 9 - Climatewell sorption chiller connection kit 3. Pipings connections The installation of the hydraulic connections of the whole system finished in December The pipes were first taken to the roof, Picture 10, and later connected to the solar collectors and the Dry Cooler, as shown in Picture 11. Picture 10 - tubes rising up from ground floor Picture 10 captures the point where the tubes coming from the technical room arrive on the roof. Two of the five pipes make up the solar collectors circuit, other two of them make up the supply and return lines of the dry cooler hydraulic circuit, and the last one contains the electrical power supply of the dry cooler. The plumbing system supports the parallel connection of the six groups of solar collectors. 7

8 Picture 11 - Plumbing for collectors and dry cooler The pipes were covered with their insulation after the connection of the whole system. The insulation, black in Picture 12, was finally protected with an aluminum coverage. : Picture 12 - Insulation of the tubes 4. Energy Box The Energy Box (EB) assembly by Riello was completed at the end of January Shortly after, it was brought to Bronzolo and installed in a dedicated technical room. From the practical point of view, the Bronzolo s Energy Box consists of two components, one hydraulic and one electric and electronic. The hydraulic part of the Energy Box contains 2 heat exchangers, 4 pumps (one for each circuits: primary, secondary, distribution and heat rejection), 4 valves (V-2, V-3, V-4 and V-14), 23 temperature sensors as well as 5 flow meters. In Picture 13, which has been taken before the sensors were connected to the electronic part of the EB, it is possible to see these components: volumetric flow meters (yellow square), temperature sensors (blue square), valves (orange square), pumps (white square) and heat exchangers (green square). 8

9 Picture 13 Energy Box In the same period of time the electrical and electronic box shown Picture 14 was also installed: it is the derivation point of all the power supply lines connected to the EB components and the housing of all the electronic components making up the EB digital control system (see ). Picture 14 - Energy Box control panel During the month of February 2011 most of the hydraulic and electrical connections regarding the EB were carried out with the pipes ready to be covered with their insulation, Picture 15. 9

10 Picture 15 Plumbing connections of Energy Box 5. System finalization The installation of the hardware was concluded in April At that time all the systems were connected both electrically and hydraulically, all the pipes were insulated and all the electronic equipment was installed and connected to the relevant sensors and actuators. Moreover, the hydraulic circuits were filled with water or the water/glycol solution according to their function. The control software, developed in the meanwhile, was installed and tested during the month of May First operations with the new solar heating and cooling system started on June 2011, with the whole system up and running. Picture 16 show on the left the inner layout of the electrical and electronic cubicle after its completion. In the picture is highlighted the position of the energy meters (red square) and that of the data acquisition hardware (yellow square). On the right, the final outlook of the EB hydraulic part. The insulations of the tubes inside the energy box are clearly visible as are the electrical connections of the sensors and pumps. Picture 17 shows the heat exchanger of the new DHW circuit, an overview of the technical room and the storage tank after completion of the installation operations, respectively. Picture 18 reports finally on the solar collectors field after completion solar of the pipings insulation. 10

11 Picture 16 Finished electrical control panel (left) and hydraulic control (right) Picture 17 DHW heat exchangers (left) and storage tank (right) 11

12 Picture 18 solar collectors after finalization of the pipings insulation 12