DETERMINING THE OPTIMUM POWER OF AN ABSORPTION HEAT PUMP WHEN IT INTEGRATING TO PT-60/70-130/13 THERMAL SCHEME

Abstract

The problem of determining the optimal thermal power of an absorption heat pump with steam heating at one-stage regeneration (COP = 1.71) is solved. The heat pump is integrated into the thermal scheme of PT-60/70-130/13 steam turbine. The heat supply schedule for this steam turbine cycle is 150/70 °С. The installation also produces steam for technological needs. The thermal and flow rate characteristics of an absorption heat pump are determined using the constructed and proposed approximation mathematical model. Based on the analysis and existing experience, an optimization problem was formulated. The goal function is to select the integrated absorption heat optimal power pump with the condition of optimal energy fuel consumption. The search for the optimal thermal power of an absorption heat pump was carried out under the condition of steam release through a controlled production turbine extraction with parameters of 1.296 MPa, 280 °C. Options for variable steam consumption for process needs (0, 20, 50 and 80 t/h) were considered. The condition was constancy of consumption throughout the year. The results obtained showed that, relative to all considered turbine loading modes, the optimal power value of the absorption heat pump is identical and amounts to ~ 17.25 MW. Calculation studies have shown that at a cost of electricity of 0.13 USD/(kWh) and equivalent fuel of 309 USD/t, a power unit with PT-60/70-130/13 turbine and an integrated absorption heat pump (thermal power 15–18 MW) with a production load of more than 20 t/h of steam, as well as a consumption of recycled network water for heat supply of more than ~ 1550 t/h, the payback of the energy saving project will be achieved in less than 3 years. The next positive effect is that fuel savings can reduce CO2 emissions by 9321 tons and NOx by 48 tons. According to research results, we observe a positive environmental effect from the integration of an absorption heat pump into the existing thermal scheme.