The Research On Applicability Of The Modular Boiler With Small Water Capacity In Hotel Building Based On Primary-secondary Pumping Heating System

In recent years,with the rapid development of tourism,hotel buildings in various cities increase a lot,which puts forward higher requirements for the energy consumption of hotel buildings.This paper analyzes the heating load characteristics of hotel buildings,and then selects a star hotel in Nanjing as the research object.Based on the analysis of its heating load rate,the optimization of heat source scheme and transmission system is taken as the main research optimization content,and the transformation benefits of heating system are analyzed from three aspects of energy-saving benefits,economic benefits and environmental benefits.Firstly,the paper analyzes the heating load data of four hotels,and finds that the load rate has a strong correlation with outdoor air temperature and hotel occupancy rate.Select a star hotel in Nanjing as the research object,and analyze the heat load rate of the hotel in heating season.The results show that the heating days with load rate of more than 90%,75%?90%,50%?75%,25%?50%and less than 25%are respectively 8days,22 days,24 days,41 days and 15 days,accounting for 7.3%,20%,21.8%,37.3%and 13.6%respectively.Low load operation accounts for a significant proportion of heating season.Based on this,The total heating load and hot water load of the reconstructed part of the hotel are calculated to be 1854.8kW and 611kW respectively.From the advantages and disadvantages of the heat source scheme,the operating efficiency under part of the load condition and the economy,it is determined that the optimal heat source scheme for the reconstruction project of the hotel is the modular gas boiler with small water capacity,and two EB-4000C are selected to meet the heating demand of guest room,eight BTS-338 are selected to directly supply the hot water demand of guest room,and the boiler room is reconstructed,saving 87%of the land area of boiler compared with that before the reconstruction.Secondly,through the comparison of transmission and distribution system schemes,the two-stage pump system which can better adapt to the intermittent heat demand is selected,through hydraulic calculation,the total resistance loss and local resistance loss of the water system on the heat network side and heat source side are 91 kPa and 41.9kPa respectively.The heat source side adopts one boiler one pump system,the flow and lift of a single circulating water pump are 47.33m³/h and 9.2mH₂O respectively;the flow and lift of the circulating water pump at the heat network side are 181.0m³/h and14.7m H₂O respectively,two circulating water pumps are selected,one for use and one for standby.Finally,from the energy-saving benefits,economic benefits,environmental benefits and other three aspects of the hotel building heating system transformation benefits are analyzed.The results are as follows:the occupancy index of heating energy consumption?RC?of hotel buildings is proposed.According to the statistics of gas consumption before and after the renovation of boiler room in the heating season?November to March?,the occupancy index of heating energy consumption of hotel buildings in each month of the heating period is calculated,and the percentage of reduction of the occupancy index of heating energy consumption after the optimization of boiler room renovation is calculated,that is,the energy saving rate,November,December,January and February In March,31.6%,23.7%,22.1%,22.2%and 29.1%of the energy-saving rate of the boiler house were optimized through the transformation,with an average energy-saving of 25.8%.The energy-saving effect was obvious.The economic efficiency of the heating system before and after the transformation was analyzed and compared by the static investment recovery period evaluation index.The total investment in the heating system transformation was 734,000 yuan,and the annual operation cost saved after the transformation was 179,000 yuan,and the investment recovery period is only 4.1 years,which is economically feasible;after the reform of heating system,the gas consumption of heating month is reduced by 22.6%on average.It is 62.5%lower than the average value of NO_x emission of traditional gas-fired boiler.