Power cold combined supplying system suitable for recycling temperature varying heat source

[0044] Example one

[0045] figure 2 It is a schematic structural diagram of a power-cooling cogeneration system suitable for recovering variable temperature heat sources according to the first embodiment of the present invention. In the power-cooling cogeneration system, valves V02, V04, V05 are closed, valves V01, V03 are opened, and ammonia The mixed working medium flows through the high-pressure generator and the low-pressure generator in sequence, and the condensation discharge drives the single- and double-effect composite lithium bromide absorption refrigerator to operate. When the temperature of the variable temperature heat source is low, it is necessary to increase the phase change evaporation temperature rise range of the ammonia water mixture to facilitate the ammonia water Rankine cycle to match the temperature of the variable temperature waste heat source. For the ammonia-water mixture with a large temperature change range during the condensation process, in order to recover the condensation heat, whether it is a single-effect lithium bromide unit or a double-effect lithium bromide unit, the temperature change range of the lithium bromide solution is relatively small, so it is necessary to introduce a single- and double-effect composite lithium bromide refrigerator. The single- and double-effect composite refrigerator can be regarded as a single-effect unit and a double-effect unit. The single-effect unit and the double-effect unit share the absorber 9, evaporator 8, condenser 7, and low temperature solution heat exchanger 11 , The generator of the single-effect machine is integrated with the low-voltage generator of the double-effect machine to form a hybrid low-voltage generator 6. The hybrid low-pressure generator can be driven by two heat sources. The low-pressure generator of the double-effect machine uses the refrigerant steam of the high-pressure generator as the driving heat source, and the generator of the single-effect machine uses the partially condensed ammonia after being cooled by the high-pressure generator. Mixed steam is the driving heat source.

[0046] The ammonia Rankine cycle condensation process is: turbine 3 outlet→high pressure generator 5→mixed low pressure generator 6→pump 1 inlet. The high-pressure generator and the mixed low-pressure generator are not only the condenser of the ammonia water Rankine cycle, but also the generator of the single and double-effect composite lithium bromide absorption chiller. The ammonia water mixture of the ammonia water Rankine cycle is in the high-pressure generator 5 and the low-pressure generator 6. Condensation, release of heat, and the heat of condensation is used to drive the lithium bromide absorption refrigerator. The hybrid low-pressure generator can be driven by two heat sources, one is the condensation heat of the refrigerant water, and the second is the condensation heat of the ammonia water mixture. In the lithium bromide absorption refrigeration cycle, the dilute solution from the low-temperature solution heat exchanger 11 is divided into two sections, one is depressurized by the throttle valve V7 and then enters the hybrid low-pressure generator 6, and the other enters through the high-temperature solution heat exchanger High voltage generator 5. The lithium bromide solution entering the low-pressure generator works in a single-effect lithium bromide unit process, and the lithium bromide solution entering the high-pressure generator 5 works in a double-effect lithium bromide unit process.

[0047] Example two

[0048] image 3 It is a schematic structural diagram of a power and cooling cogeneration system suitable for recovering variable temperature heat sources according to the second embodiment of the present invention. In the power and cooling cogeneration system, valves V01 and V05 are closed, valves V02, V03, and V04 are opened, and ammonia The mixed working fluid only flows through the low-pressure generator, and runs in the manner of a single-effect lithium bromide absorption chiller driven by an ammonia Rankine cycle. Ammonia Rankine cycle condensation process is: Turbine 3 outlet → Hybrid low-pressure generator 6 → Pump 1 inlet. Among them, the low-pressure generator is the condenser of the ammonia water Rankine cycle, and is also the solution generator of the lithium bromide absorption refrigerator. The condensation heat of the ammonia water Rankine cycle drives the lithium bromide absorption refrigerator to work. In the lithium bromide absorption refrigeration cycle, the refrigerant from the hybrid low-pressure generator 6 is condensed in the condenser 7, throttling and depressurizing through the throttle valve V2, and enters the evaporator 8 to evaporate to generate cooling load. The evaporated water vapor enters the absorption The device 9 is absorbed by the concentrated lithium bromide solution from the low-temperature solution heat exchanger 11 and then enters the solution pump 10 for pressurization, and enters the low-temperature solution heat exchanger to recover the heat of the concentrated lithium bromide solution. The dilute solution from the low-temperature solution heat exchanger 10 directly enters the low-pressure generator 6, is heated by the condensation heat of the ammonia water Rankine cycle, and becomes a concentrated lithium bromide solution after releasing the refrigerant vapor, and enters the low-temperature solution heat exchanger 10 to exchange heat with the dilute solution. The dilute solution throttle valve V6 decompresses and enters the lithium bromide absorber 9.

[0049] Example three

[0050] Figure 4 It is a schematic structural diagram of a power and cooling cogeneration system suitable for recovering variable temperature heat sources according to the third embodiment of the present invention. In the power and cooling cogeneration system, valves V03 and V04 are closed, and valves V01, V02, and V05 are open. The cooling co-supply system drives the operation of the double-effect lithium bromide absorption chiller with the ammonia Rankine cycle. Ammonia Rankine cycle condensation process is: turbine 3 outlet → high pressure generator 5 → pump 1 inlet. Among them, the high-pressure generator is the condenser of the ammonia water Rankine cycle, and is also the high-pressure generator of the lithium bromide absorption refrigerator. The ammonia water mixture of the ammonia water Rankine cycle is condensed in the high-pressure generator 5 to release heat, and the heat of condensation is used to drive the lithium bromide absorption type The refrigerator works, and the lithium bromide refrigerator works in double-effect unit mode. In the lithium bromide absorption refrigeration cycle, the dilute solution from the high-temperature solution heat exchanger 11 directly enters the high-pressure generator 5, is heated by the condensation heat of the ammonia water Rankine cycle, and becomes an intermediate concentration lithium bromide solution after the refrigerant vapor is released, and enters the high-temperature solution heat exchanger 11 Exchanges heat with the dilute solution, passes through the intermediate concentration solution throttle valve V8 and then enters the mixed low pressure generator 6, after being heated again, evaporates and releases the refrigerant vapor to become a concentrated lithium bromide solution, enters the low temperature solution heat exchanger 11, and passes through the throttle valve V3 enters the lithium bromide absorber 9. The refrigerant water vapor produced by the high-pressure generator 5 enters the mixed low-pressure generator 6, releases condensation heat to heat the lithium bromide solution with an intermediate concentration, and enters the condenser 7 through the refrigerant throttle valve V1 after condensation, and mixes and condenses with the refrigerant produced by the low-pressure generator Liquid water enters the evaporator through the throttle valve V2 to evaporate, and the refrigerant vapor is absorbed by the concentrated lithium bromide solution from 11 in the absorber 9.

[0051] In order to better reflect the beneficial effects of the power-cooling cogeneration system with adjustable output power and cooling ratio provided by the present invention, the above three embodiments and the traditional waste heat directly drive the lithium bromide absorption refrigeration system to perform performance under the same thermal boundary conditions. Compare. The variable temperature heat source is selected as a certain model of gas turbine exhaust, and the four systems are simulated and calculated. Because the new system proposed by the present invention has two energy outputs for power and cooling, and the traditional system has only one energy output for cooling capacity, in the performance comparison, an electric compression refrigerator is used to convert the work output from the power and cooling cogeneration system into cooling load. . Table 1 compares the performance of the four systems.

[0052] Item

[0053] Lithium Bromide Absorption Chiller COP

[0054] Table 1

[0055] From the calculation results, the final output cooling load of the three embodiments of the present invention is greater than the output cooling load of the lithium bromide absorption chiller directly driven by the flue gas, and the thermal performance of the new system is better than the comparison system. The heat source conditions of the four systems are exactly the same. The flue gas waste heat is used from 573°C to 170°C, the flue gas flow rate is 7.93Kg/s, and the flue gas heat recovery is 3557kW.

[0056] In the first embodiment, the output power is 734kW, and the output cooling load is 2668kW. After the electric power is converted into cooling load through electric compression refrigeration, the total output cooling load of the embodiment is 5971kW.

[0057] In the second embodiment, the output power is 969kW and the output cooling load is 1996kW. After the electric power is converted into cooling load through electric compression refrigeration, the total output cooling load of the embodiment is 6357kW.

[0058] The output power of the third embodiment is 699kW and the output cooling load is 3598kW. After the electric power is transformed into cooling load through electric compression refrigeration, the total output of the cooling load is 6744kW in the embodiment.

[0059] The comparison system is that the flue gas directly drives a double-effect lithium bromide absorption chiller with an output cooling load of 4478kW.

[0060] From the calculation results, the three embodiments of the present invention change the composition of the ammonia-water mixed working fluid, change the condensing pressure, and output different amounts of electric load and cooling load, thereby realizing the adjustable power-to-cooling ratio of the system.

[0061] Example 1 The concentration of ammonia as a mixed working fluid of ammonia is increased to 35%, the condensing pressure is increased to 0.72MPa, and the condensing temperature range is 198~75℃. It drives a single- and double-effect composite lithium bromide refrigerator with an output power of 733.9kW and an output cooling load of 2667.9kW .

[0062] Example 2 Ammonia mixed working fluid concentration is 8%, condensation pressure is 0.1MPa, condensation temperature drop range is 97-74.6°C, single-effect lithium bromide refrigerator is driven, output power is 969kW, and output cooling load is 1996kW.

[0063] In the embodiment, the concentration of the mixed working fluid of triammonia water is unchanged at 8%, the condensing pressure is increased to 0.6Mpa, and the condensing temperature drop range is 155-132°C. The double-effect lithium bromide refrigerator is driven, and the output power is 699kW and the output cooling load is 3598kW.