The greenhouses play a key role in food sustainable production, the purpose of the greenhouses is to make an artificial suitable environment to grow different kinds of plants. The cost of energy used in the greenhouses to ensure the optimum temperature, humidity, and CO2 concentration, makes up a large part of the final cost of food. Due to global warming, the successive energy crises, and the food crises, the need to make the greenhouses more energy efficient and to utilize renewable energy resources is rapidly increasing. The enclosed water curtain cooling system meets the special requirement of the greenhouse cooling system, and it has potential energy savings when it is integrated with other systems such as heat pumps, underground water sources, and surplus heat energy recovery. This system involves two special nylon foils, and a thin layer of water flows between the two foils, the two foils will be stuck to eachother by the cohesive force of the water-detergent mixture, the detergent was added to decrease the water surface tension and ensure the even distribution of the water-detergent mixture over the nylon foils. In this study, an experimental model of the enclosed water curtain was made and two sets of tests were conducted, the first set was at room temperature around 20°C, and the second test was at room temperature around 25.7 °C with an electrical heater, each set contains three tests to measure the cooling capacity of the curtain, and each test takes 2 minutes, the curtain dimensions were height and width of 1.04 m and 1.20 m respectively. By measuring the difference between the average inlet and outlet temperature of the water-detergent mixture before and after the curtain, and the mixture mass flow rate during the test period, the cooling capacityof the curtain was calculated using the energy balance equation.It was found that the curtain cooling capacity increases with the increase of ambient temperature, The large heat transfer area of the curtain which allows using higher water temperature for cooling, and the useful features of the water membrane like the high absorption of the wavelength of infrared and the high transparency of the wavelength of visible light, make this system meets the special requirements of the greenhouses cooling system. However, to be able to apply this system in real-life, the design of the curtain should be improved, and suitable materials should be chosen to make it more reliable. Also, All tests in this study were conducted in the workshop in the absence of solar radiation, therefore, the actual performance of the curtain needs to be evaluated with the presence of solar radiation, to be able to study the effects of the direct and diffuse solar radiation with various spectrum range.

Energieffektivisering är intressant för alla industrier, eftersom det handlar om minskning av både energianvändning och kostnad. Syftet med detta examensarbete är att analysera potentiell energiåtervinning av spillvärme från en mangel vid Limatvätten AB. Limatvätten AB är en stor och modern tvätterianläggning. Limatvätten tvättar åt främst hotell- och restaurangkunder. Limatvätten AB har egna textilier som hyrs ut till hotell, konferenser m.m. Största kunderna finns i Sälenfjällen och Siljansregionen. Då inga processdata fanns tillgängliga för detta arbete krävdes mätningar för att få basinformationen. Utifrån mätningar beräknas mängden av energi som kan återvinnas. Systemförslag för värmeåtervinning ges även i rapporten. Aquavent är en värmeväxlare som använder ventilationsvärme från manglar. Vattnet som värms upp i aquavent leds in i tvättrören, vilket leder till minskning av ångförbrukning i tvättprocesser. Temperaturförändring är beroende av värmeväxlarens verkningsgrad, ju högre temperaturförändring det är desto mer mängd av energiåtervinning fås. Efter identifiering av problemet kartlades tidsplan, lämpliga instrument samt intressanta parametrar. Fukthalten, temperaturen och dynamiska trycket har mätts. Formlerna som beskrivs i teoriavsnittet har använts till de flesta beräkningarna med hjälp av Excel. Av resultatet framkommer att maximala energibesparingen blir 184 MWh/år om all överskottsvärme från manglarna återanvänds. Utifrån resultatet blir den totala besparingspotentialen på 57 000 SEK/år. Ytterligare kompletterande mätningar och analyser behövs för att få tillräckligt bra beslutsunderlag. Men detta arbete tyder på att ytterligare analys är intressant. Resultaten visar det att finns potential att använda överskottsvärme från Limatvättens manglar. Förutom besparingen av energin så minskas också klimatpåverkan eftersom överskottsenergin återanvänds igen som annars skulle försvinna ut i atmosfären. Om två av manglarna kopplas med ett värmeåtervinningssystem, resulterar det en dubblering på besparingspotentialen. För att få ett mera noggrant resultat kunde man logga en längre tid för mätningarna för att se förändring kring de mätande storheterna t.ex. genom att installera mätare som loggar till en dag eller till med en vecka. Övervakning och tolererande givare behövs dock. / Energy efficiency is in the interest of all industries, as it involves the reduction of both energy and cost. The purpose of this project for a bachelor’s degree is to analyse potential energy recovery of waste heat from an ironer. The work was carried out at Limatvätten AB, which is a large and modern laundry facility. Limatvätten AB is a textile service company that has been in existence for 50 years. The Lima laundry’s main customers are from the hotel and restaurant business. Limatvätten AB has its own textiles that are rented to hotels, conferences, etc. The largest customers are in Sälenfjällen and in the Siljan region. The work is done by identifying moisture, temperature and dynamic pressure in an ironer Based on measurements, the amount of energy that can be recycled is calculated. Heat recovery system proposals are also given in the report. Aquavent is a heat exchanger that uses ventilation heat from the ironers. The water that is heated in the aquavent is led into the washing pipes, which leads to the reduction of steam consumption in washing processes. Temperature change depends on the heat exchanger's efficiency, the higher the temperature change, the more amount of energy recovery is obtained. After identification of the problem, a timetable was mapped, and appropriate instruments and interesting parameters were chosen. The moisture content, temperature and dynamic pressure have been measured. The equations described in the theory section are used for most of the calculations with the help of Excel. According to the result, the energy saving will be 184 MWh/year if all excess heat from a mangle is reused. Based on the result, the total savings potential is SEK 57 000 /year. According to the results, it is shown that there is the potential to use excess heat from the Lima wash ironers. In addition to the saving of energy, climate impact is also reduced, as the excess energy is again reused which would otherwise disappear into the atmosphere. If two of the ironers are coupled with a heat recovery system, it results in a doubling on the savings potential.