Restvärmetillförsel i Ludvikas Fjärrvärmesystem : Påverkan på befintlig värmeproduktion vid olika inkopplingsscenarier av 60°C restvärme

Sammanfattning: Energy company Vattenfall AB has set an ambitious goal in trying to transform their business into a climate neutral and more resource effective company - all within thetime frame of one generation. Through the business concept “SamEnergi” within the heat sector, Vattenfall looks for district heating customers who are willing to sell heat at a price corresponding to Vattenfall’s own production cost. This report examines the change in ordinary heat production in the partially Vattenfall-owned district heating system in the city of Ludvika, Sweden, arising from the delivery of waste heat from a data center to the system. The data center delivers 1 MW heat at 60 degrees Celsius which is lower than the desired temperature in the district heating grid. The change in ordinary heat production is evaluated in four different scenarios where each scenario represents a way to connect the heat source to the district heating grid, so that the delivery temperature to the costumer is not affected. In two of the scenarios, the data center is placed on site of the main heat production units. For all four scenarios, the ability to deliver heat during normal annual fluctuations in flow and temperature in the district heating grid are assessed. Also, in one scenario the effecton a flue gas condenser is considered. The heat production for a normal year is then modelled and simulated using an optimization software called BoFiT, with and without the excess heat. The results show that the 1 MW excess heat is worth between 0,9 and 1,8 million SEK depending on how the heat is delivered. The lowest value of the excess heat source comes from the scenario requiring a heat pump. The other three scenarios yield similar savings on the ordinary production. The best scenario is when the waste heat is delivered together with the main production unit.