1、2010 ASHRAE 227ABSTRACTThis paper describes the Slovenian Beach system con-structed in the town of Budva at the Adriatic sea coast 26years ago, its technological schemes, construction, scenariosand regimes of control based on the solar radiation intensitymeasurement, as well as 25 years of its succe
2、ssful operation.The 3.5MW multipurpose solar system combined with a sea-water heat pump is providing complex of hotel buildings withsanitary and swimming pool water heating, hotel roomsspace heating and air-conditioning. The system in SlovenianBeach has total power of 3,5 MW and includes a 2.500 m2(
3、26,909.78 ft2) flat plate solar collectors field and three heatpumps with total of 930 kW heating and 720 kW coolingcapacities. Heat pumps are used for supplemental heating inthe winter and for cooling during the summer. Sea water isused either as a heat source or as a heat sink for heat pumpoperati
4、on. Finally, presented will be recorded data of usefulenergy output as well as experience with the 25-year seawater usage influence on heat exchangers, and solar collec-tors aging influence on the system efficiency.INTRODUCTIONActive use of solar radiation energy in Montenegro andSerbia is a part of
5、 the most precious history of the developmentof solar technologies in Europe. It represents a commercial-ized use of the renewable energy resources in Europe, whererecently in its most developed regionthe European Unioncountriesmore and more systems are constructed similar tothe Seawater Heat Pump A
6、ssisted Multipurpose Solar Systemwhich has been successfully functioning in Budva, Montene-gro, at the Adriatic sea coast for 25 years now.The tourist Hotel complex apartment-type SlovenskaPlaa (a view on the hotel complex apartment buildings ofSlovenian Beach is given in the Figure 1) represents a
7、uniqueform of tourist offer at the Adriatic coast. The entire complexwith 754 rooms and 220 apartments, was designed to have vari-ous contents that meet all the requirements of its guests. Everyroom has a balcony while each apartment includes a kitchenalong with a dining room. Following the completi
8、on of itsconstruction, the facility was able to accommodate 2700 guestsFigure 1 Hotel apartment complex Slovenian Beach in Budva.3.5 MW Seawater Heat Pump Assisted Multipurpose Solar Systems 25 Years of OperationMarija S. Todorovic, PhD, PE Slobodan Pejkovic, PE Vido Zenovic, PEFellow ASHRAEM.S. Tod
9、orovic is professor at the University of Belgrade and director of the VEA-INVI Ltd., Belgrade, Serbia. S. Pejkovic is director of theFilterfrigo Ltd, Belgrade, Serbia. V. Zenovic is head of the Development Group of the Rivijera Hotel/Touristic Ltd., Budva, Montenegro.OR-10-025 2010, American Society
10、 of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org). Published in ASHRAE Transactions 2010, Vol. 116, Part 1. For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAEs prior written perm
11、ission. 228 ASHRAE Transactionsat a time. The major part of the accommodation area is air-conditioned, while the common areas are fully air-conditioned.The tourist complex “Slovenian Beach” is located nearthe natural beachsandy and pebbly (Figure 2), both on theshore and in the sea. It stretches fro
12、m the city harbor to theanother hotel complexnamed Park, with the total length of1600 m (5249.344 ft). It is characteristic for its sandbankwhich connects the beach with the island St. Nikola. It offi-cially became the swimming beach in 1920, and Czechs whowere on holiday there in 1935 named it “Slo
13、venska plaa” asit is called today.The tourist complex Slovenian Beach in Budva has beenintended to accommodate tourists throughout the year and itwas expected to be used at least eight months a year. A deci-sion to build the Slovenian BeachHeat Pump assisted SolarSystem had been made at the Budva Ho
14、tel Touristy organiza-tion 29 years ago, in 1980. Corresponding ConstructionContract was signed one year later in 1981 and immediatelyafter its conclusion activities regarding the system design,selection of potential equipment and its procurement began. Avery creative mechanical engineer, HVAC syste
15、m designexpert Mr. Velimir Jevtic was the main designer of the system.Its construction was completed in April 1983.The system used in Slovenian Beach has total power of3,5 MW and includes a 2.500 m2 (26,909.78 ft2) flat plate solarcollectors field for water heating (Figure 3). The heat pumps(Figure
16、4) are designed and sized to be used for additionalsanitary water heating in summer when solar radiation inten-sity is of too low level, and for heating in winter, as well as forair-conditioning during the summer. Sea water is used as heatsource and heat sink for heat pump operation.Further in this
17、paper the Slovenian Beach heat pumpassisted solar system constructed in Budva at the Adriaticcoast, its technological schemes, construction, scenarios andregimes of control based on the solar radiation intensitymeasurement and solar collector field outlet water tempera-ture, as well as 25 years of i
18、ts operation are described.Figure 2 Sandy and pebbly Slovenian Beach in Budva.Figure 3 Slovenian BeachSeawater heat pump assistedsolar systems flat plate collector field.Figure 4 Slovenian BeachHeat pump assisted solar sys-tem: heat pumps in machinery room. 2010, American Society of Heating, Refrige
19、rating and Air-Conditioning Engineers, Inc. (www.ashrae.org). Published in ASHRAE Transactions 2010, Vol. 116, Part 1. For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAEs prior written permission. ASHRAE Trans
20、actions 229SOLAR THERMAL AND HEAT PUMP TECHNOLOGIES STATUS 25 YEARS AGOThe installations of solar water heating systems, commer-cially available 25 years ago in European countries and usedfor warm water supply of family dwellings, hotels and publicbuildings, as well as for swimming pools and low-tem
21、peratureheating of low-rise residential, agricultural and industrialbuildings, have technically been at the acceptable level ofmaturity. At the same time, a lot of experience had been accu-mulated also regarding the operation of these installationsunder different climatic conditions.The results of r
22、esearch and development of solar technol-ogies at that time did show that both passive and active systemsof solar heat supply were feasible and could have beensuccessfully used in practice, and that there were already agreat number of examples for their efficient application. At thesame time the fla
23、t plate solar collector production and design-ing and engineering experience of heat pumps commercialimplementation, as well as heat pumps manufacturing tech-nologies and industrial production were also at the significantlevel of maturity and quality.Technologies of low-temperature active and passiv
24、e solarheating including short-term heat thermal energy storage havealso been developed. In addition, in order to broaden, as muchas possible, the utilization of solar energy, a number of inno-vative and research and development studies were in progres-sive performance in order to improve further th
25、e technicalcharacteristics of the solar systems, their cost-effectiveness,durability and efficiency.SOLAR SYSTEMS EXPERIMENTING, APPLIED RESEARCH AND DEVELOPMENT IN WESTERN BALKAN COUNTRIESBetween 1980 and 1983 an extensive solar systems exper-imenting had been conducted: several different central s
26、olarwater heating systems were tested and short - term monitoredin different climatic conditions in former Yugoslavia, so calledWestern Balkan countries today. One of them in a coastal area,the other one in the continental region, and the remaining threein mountainous continental and the southern co
27、ntinentalregion of the country (Todorovic 1983, 1988). The size of thecollector areas of the tested systems varied between 30 and600 m2(322.91 and 6458.34 ft2) and the capacity of the waterstorage tanks was between 3 to 40 m3(105.94 to 1412.58 ft3).During the testing measured were some 80 different
28、parame-ters (the intensity of global and diffuse radiation, a number ofrelevant temperature values, the flow-rate of heating fluid,wind velocity, the relative humidity of air, the composition ofheat transfer fluid, its physical properties, etc.). The qualita-tive and quantitative assessment and comp
29、arison of thesesystems were carried out by the determination and analysis ofthe most important solar systems relevant parameters: theenergy flux of solar radiation, the received useful heat, theinput and output heat flows of various components of thesystems, the share of solar energy in the final en
30、ergy use of thesystem, the thermal efficiency of the components and thewhole system efficiency according to the I and II law of ther-modynamics (Todorovic 1985).As a major part of the heat losses occur after collection inthe heat exchangers and in the heat storage, even in a greaterextent depending
31、upon the way and form of heat consumption,it is clear how important is to study the change of efficiency inthe secondary parts of the solar system. The electricityconsumption of solar plants, including the energy demand ofmeasuring and control instruments is minimal, and variedbetween 2.7 and 4.0% o
32、f the total power input. The function-ing of components and the system, the operating performanceand the costs of the systems were also compared.The results of conducted solar systems testing and exper-imenting were very valuable experience on the solar systemsefficiency and contributed significantl
33、y to advance under-standing of the systems performance dynamics. The resultsbecame reliable data, based on which systems designing andengineering development in the region had been enhanced andintensified. Corresponding solar thermal systems perfor-mance data did confirm that in diverse climatic con
34、ditions inWestern Balkan countries multipurpose systems, central heat-ing and cooling plants, designed and constructed to supplyyear round air conditioning, warm and hot water or processheat can operate efficiently and be cost-effective.Available reports were describing variety of systemsconfigurati
35、on, heat pump assisted (vapor-compression andabsorption type coupled with different additional heat sources,ground, water or air, including waste heat streams) for resi-dential, commercial buildings, apartment complexes or urbansettlements.Also, experimental results did show that TES (thermalenergy
36、storage), as an important mean to increase overallenergy efficiency and reduce final energy use in energy con-version processes and plants in general, is however inherent tothe solar thermal systems, and its sizing can be crucial for thewhole system efficiency. In addition, as a more effective forTE
37、S implementation substances with much higher thermalcapacities have been objective of research, particularly in Ser-bia. A number of solid/liquid and solid/solid phase changematerials, exhibiting high energy storage density and smalloperating temperature variations have been screened andinvestigated
38、 established data bases make them useful for pas-sive-solar and active-solar systems development.As far as the operation of tested plants is concerned, it hasbeen concluded that during major part of the test periods, thesystems were operated without any serious faults, controlledautomatically by dif
39、ferential thermostats. Although the mea-suring systems did not include units for automatic data collec-tion, i.e., for continuous measuring of all parameters, it did,however, allow a relatively frequent measurement of relevantparameters. The actual reading and recording of the mostimportant paramete
40、rs were taken more frequently thandesigned in the project plan and testing programme, in order to 2010, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org). Published in ASHRAE Transactions 2010, Vol. 116, Part 1. For personal use only. Additional reprodu
41、ction, distribution, or transmission in either print or digital form is not permitted without ASHRAEs prior written permission. 230 ASHRAE Transactionscollect basic data for the simulation model to study the dynam-ics of particularly important transition periods of the operation.SYSTEMS MULTIPURPOSE
42、 DEMAND SIDE DESCRIPTIONSanitary Water HeatingThe main task of the power plant Slovenian Beach was toprovide sanitary water heating for the hotel apartment buildingcomplex (Zenovic and Jevtic 1981.). The design conditions forthe system, primarily the daily consumption of 600 m3sani-tary warm water a
43、t 45C (113F) temperature were defined.Calculation and analysis of sanitary hot water consump-tion was performed according to the ASHRAE handbook. Itwas estimated that the dynamics of hourly demand of the sani-tary hot water varies between 13.2 and 57 t/h. The totalconsumption of sanitary hot water r
44、epresents the sum of thehotel accommodation (apartment) section consumption (71%)and the restaurant section consumption (29%).On the diagram in Figure 5, the line marked TP representsthe total amount of produced sanitary warm water (SWW), byboth solar energy and the heat pumps (HP). The same diagram
45、shows the curves of the daily dynamics of the amounts of sani-tary water heated by solar energy (marked with S), and amountof water heated by heat pumps (by operation of one heatpumpmarked with HP1, and by operation of two heat pumpsmarked with HP2). By adding S and HP1 or HP2, i.e., bothparts, wate
46、r heated by solar energy and water heated by heatpump, the curves S+HP1, and S+HP2 have been obtained. Thedynamics of the change during 24 h of difference of the totalproduction curve (TP) and the total consumption C shows thedynamics of changes in the conditions of the thermal energystorage (TES),
47、i.e., hot water storage. The two characteristicconditions in the thermal energy storage, i.e., minimum andmaximum and minimum “charge” have been marked asTESmin and TESmax.Seven hot water storage tanks have been designed in orderto be integrated in the system, each with the volume of 50 m3(1765.733
48、ft3), i.e., the total volume of TES is 350 m3(12,360.13 ft3). In order to enable the control of stratificationof various temperature layers and contribute to increase of thethermal efficiency of the entire system, storages were dividedinto several temperature levels by the “charge” control system.In
49、 the Figure 6 TES tanks, collectors “field” as a parking lotroof, as well as meteorological station are shown.The control of the sanitary hot water preparation by thesolar system is solved as follows: the nominal (design) waterflow rate in the solar part of the system is 55 m3/h (1942.307ft3/h), and water temperature of 55/45C (131/113F) is main-tained constant by the control of the variable flow rate throughthe collector field, depending on the solar radiation intensity.Thereby, the flow rate is not meant to be 25% lower than thenominal (design) one. The heating o
