Energy-saving air conditioning system with cold and heat sources provided by steam waste heat and operation method

Abstract

According to the energy-saving air-conditioning system with the cold and heat sources provided by the steam waste heat and the operation method, first process equipment of the system serves as medium / high-pressure gas utilization equipment, and medium / high-pressure saturated steam is used for heating; the temperature and pressure reduction device adjusts the steam source to a saturated state, temperature reduction water of the temperature and pressure reduction device is provided by a second steam condensation water tank or a plant desalting water tank of the plant, and saturated steam after temperature and pressure reduction is conveyed to the first process equipment through a second steam pipeline; the flash tank receives and separates steam and condensate water generated by flash evaporation after steam heat exchange of the first process equipment; the steam header is used for receiving steam of the flash tank and low-pressure steam of a plant area and supplying steam to the second process equipment, the steam type lithium bromide absorption refrigerating unit and the combined air conditioning unit; the steam type lithium bromide absorption refrigerating unit provides cold water for the combined air conditioning unit in summer; and the DCS control equipment controls and monitors system operation parameters. The problems that the utilization rate of low-grade heat energy of steam and condensate water of industrial factories is low, and heat energy is wasted are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial steam waste heat utilization, and in particular relates to an energy-saving air-conditioning system and an operation method thereof, in which the waste heat of steam is used as a cold or heat source. Background Art

[0002] At present, there are obvious irrational phenomena in energy utilization in chemical and chemical fiber industry projects.

[0003] On the one hand, some production processes such as BDO units and polyester units will stably generate saturated steam of a certain pressure. If this steam is directly discharged into the atmosphere without being fully utilized, it will cause a lot of energy waste. Therefore, it is necessary to take certain measures to transport it to the user end through the plant steam pipeline network to fully utilize the waste heat of steam.

[0004] On the other hand, key areas of factories such as polyester filament and spandex spinning workshops have strict requirements on indoor temperature, humidity and cleanliness, and require pre-planning and reasonable design of centralized air-conditioning systems to maintain the production environment. Traditional centralized air-conditioning systems mostly rely on electric compression refrigeration units or heat pumps. In industrial projects, their high energy consumption problem is prominent. The installed power of refrigeration equipment can reach several thousand kilowatts, and the electricity consumption is huge. Moreover, power restrictions during peak hours will affect the normal production, increase the operating costs of enterprises, and do not meet the sustainable development requirements of energy conservation and consumption reduction. Summary of the invention

[0005] To this end, the present invention provides an energy-saving air-conditioning system and an operating method that use steam waste heat to provide cold and heat sources, so as to fully utilize the abundant steam and its condensed water waste heat in industrial plants, and solve the problems of low utilization rate and waste of low-grade thermal energy of steam and its condensed water in industrial plants.

[0006] In order to achieve the above object, the present invention provides the following technical solution: an energy-saving air-conditioning system using steam waste heat as a cold and hot source, comprising:

[0007] The first process equipment, as a medium / high pressure gas-using equipment, is heated by medium / high pressure saturated steam with a design pressure of p2;

[0008] A temperature reduction and pressure reduction device, used for adjusting the steam source with a pressure of p1 to a saturated state of p2, wherein the temperature reduction and pressure reduction device has a temperature reduction water provided by the second steam condensate water tank in the plant area or the desalted water tank in the plant area, and the saturated steam with a pressure of p2 produced by the temperature reduction and pressure reduction device is transported to the first process equipment through the second steam pipeline;

[0009] A flash tank, used for receiving and separating saturated steam and condensed water at a pressure of p3 generated by flash evaporation of steam after heat exchange in the first process equipment;

[0010] The steam cylinder is used to receive the flash tank steam and the low-pressure steam in the plant area, and supply steam to the second process equipment, the steam-type lithium bromide absorption refrigeration unit, and the combined air-conditioning unit;

[0011] Steam-type lithium bromide absorption refrigeration unit, equipped with a cold water circulation pump and a constant pressure water supply device, is used to provide cold water for the combined air conditioning unit in summer;

[0012] Combined air conditioning unit, including fresh air section, mixed air section, preheating section, heating section, surface cooling section, spray section, dry steam humidification section, blower section and other functional sections;

[0013] A steam condensate tank, comprising a first steam condensate tank and a second steam condensate tank, for collecting system steam condensate;

[0014] DCS control equipment is used to control and monitor system operating parameters.

[0015] As a preferred solution for an energy-saving air-conditioning system using waste steam heat as a cold and hot source, the temperature reduction and pressure reduction device includes two processes: pressure reduction and temperature reduction. The temperature reduction water is obtained from the second steam condensate water tank in the plant area by a temperature reduction water pump through the eighth steam condensate water pipeline, or from the desalted water tank in the plant area;

[0016] The temperature and pressure reduction device adjusts the steam source from the pressure p1 state to the saturated state p2 via the first steam pipeline;

[0017] The design pressure of the flash tank is p3, and the flash tank receives the steam condensate generated by the first process equipment through the first steam condensate pipeline.

[0018] As a preferred solution for an energy-saving air conditioning system using waste steam heat to provide cold and hot sources, the steam supply source for the sub-cylinder includes saturated steam with a pressure of p3 generated from the flash tank via a third steam pipeline, and saturated steam with a pressure of p3 from the surplus low-pressure steam network in the plant area via a fourth steam pipeline;

[0019] The output gas end of the sub-cylinder is connected to the second process equipment, the steam-type lithium bromide absorption refrigeration unit and the combined air-conditioning unit through the fifth steam pipeline, the ninth steam pipeline and the sixth steam pipeline respectively.

[0020] As a preferred solution for an energy-saving air-conditioning system that uses waste heat from steam to provide cold and heat sources, when the steam-type lithium bromide absorption refrigeration unit is operated in summer, it provides 7 / 12°C cold water to the combined air-conditioning unit through the first cold water pipe, the cold water circulation pump, and the second cold water pipe.

[0021] As a preferred solution for an energy-saving air-conditioning system that uses waste steam heat to provide cold and heat sources, the winter heating load and summer cooling load of the combined air-conditioning unit are determined through air-conditioning system load calculation based on the air-conditioning air volume, air supply temperature and humidity requirements, indoor environmental temperature and humidity and cleanliness requirements required by the process, and combined with the outdoor meteorological parameters of the project location.

[0022] As a preferred solution for an energy-saving air-conditioning system using waste steam heat as a cold and hot source, the first steam condensate tank collects the steam condensate generated by the flash tank through the second steam condensate pipeline; the first steam condensate tank collects the steam condensate generated by the second process equipment through the third steam condensate pipeline; the first steam condensate tank collects the steam condensate generated by the combined air-conditioning unit through the fifth steam condensate pipeline;

[0023] The steam-type lithium bromide absorption refrigeration unit introduces saturated or supercooled steam condensate under the steam pressure p3 used by the steam-type lithium bromide absorption refrigeration unit to the first steam condensate tank through the fourth steam condensate pipeline;

[0024] Part of the condensed water in the first steam condensed water tank is transported to the preheating section of the combined air-conditioning unit by a condensed water pump through a sixth steam condensed water pipeline to utilize waste heat, and the steam condensed water after cooling of the combined air-conditioning unit enters the second steam condensed water tank through a seventh steam condensed water pipeline;

[0025] The first steam condensate tank and the second steam condensate tank are both provided with vent holes on the top, and both are open water tanks at normal pressure. Overflow ports are provided on the upper parts of the side walls of the tank bodies of the first steam condensate tank and the second steam condensate tank, and drain ports are provided on the bottoms. Insulation materials are provided on the outer surfaces of the tank bodies, and steam condensate with the same properties as those of the designated system in the plant is collected.

[0026] As a preferred solution for an energy-saving air-conditioning system using waste steam heat as a cold and hot source, an ambient temperature transmitter with a remote indication signal is arranged outdoors, a flow meter with a remote indication signal and a steam flow regulating valve are arranged on the sixth steam pipeline, and the opening of the steam flow regulating valve of the heating section of the combined air-conditioning unit operating in winter is adjusted on the DCS control device through the combined action of the outdoor ambient temperature and humidity and the steam flow;

[0027] A flow meter with remote signal transmission and a cold water flow regulating valve are arranged on the second cold water pipeline, and the opening of the steam flow regulating valve of the steam-type lithium bromide absorption refrigeration unit operating in summer is adjusted on the DCS control device through the combined effect of outdoor environmental temperature and humidity and cold water flow.

[0028] The present invention also provides an operation method of an energy-saving air-conditioning system using waste steam heat as a cold and hot source, which is applied to the above-mentioned energy-saving air-conditioning system using waste steam heat as a cold and hot source, and comprises the following steps:

[0029] Steam pretreatment: The steam source is processed by the temperature reduction and pressure reduction device and then sent to the first process equipment, so that the steam meets the use requirements of the first process equipment;

[0030] Steam flashing and distribution: The steam condensed water generated by the first process equipment enters the flash tank for flashing, and the steam generated by the flashing and the low-pressure steam in the plant area are distributed to the second process equipment, the steam-type lithium bromide absorption refrigeration unit, and the combined air-conditioning unit through the steam distribution cylinder;

[0031] Summer cooling: The steam-type lithium bromide absorption refrigeration unit uses the steam provided by the sub-cylinder to produce cold water to provide cooling for the combined air-conditioning unit;

[0032] Winter heating: The steam from the cylinders provides heat for the combined air conditioning units;

[0033] Condensate recovery: The steam condensate generated by the system is collected in the first steam condensate tank and the second steam condensate tank and recycled.

[0034] As a preferred scheme for the operation method of an energy-saving air-conditioning system using waste heat from steam as a cold and hot source, in the steam pretreatment step, when the steam source parameter p1>p2, the pressure reducing valve of the temperature reduction and pressure reduction device reduces the pressure, and the temperature reduction water is obtained from the second steam condensate water tank or the desalted water tank in the plant area by the temperature reduction water pump. After being reduced in temperature by the desuperheater, the steam reaches a saturated state, and the instrument on the second steam pipeline feeds back the signal to the DCS control device for adjusting the steam parameters;

[0035] In the steam flashing and distribution step, the flash tank receives and separates the steam condensate of the first process equipment through the first steam condensate pipeline, the steam generated by flashing enters the steam sub-cylinder through the third steam pipeline, and the low-pressure steam of the plant enters the steam sub-cylinder through the fourth steam pipeline. The sub-cylinder distributes steam through the regulating valve according to the equipment requirements, and the liquid level gauge of the flash tank feeds back the liquid level signal to the DCS control equipment.

[0036] As a preferred scheme for the operation method of an energy-saving air-conditioning system in which waste heat from steam is used as a cold and heat source, in the summer cooling step, the steam-type lithium bromide absorption refrigeration unit generates cold water at 7 / 12°C, which is transported to the combined air-conditioning unit via a first cold water pipe, a cold water circulation pump, and a second cold water pipe. The steam condensate generated by the steam-type lithium bromide absorption refrigeration unit enters the first steam condensate tank via a fourth steam condensate pipe. The outdoor ambient temperature and humidity and the cold water flow signal of the second cold water pipe are fed back to the DCS control device for adjusting the opening of the steam flow regulating valve of the steam-type lithium bromide absorption refrigeration unit.

[0037] As a preferred scheme for the operation method of an energy-saving air-conditioning system that uses waste steam heat to provide cold and heat sources, in the winter heating step, the steam from the cylinders enters the combined air-conditioning unit through the sixth steam pipe, and the condensed water from the first steam condensate tank is transported to the preheating section of the combined air-conditioning unit through the sixth steam condensate pipe and the condensate pump, and the outdoor ambient temperature and humidity and the steam flow signal of the sixth steam pipe are fed back to the DCS control device for adjusting the opening of the steam flow regulating valve of the heating section of the combined air-conditioning unit.

[0038] As a preferred scheme for the operation method of an energy-saving air-conditioning system in which waste heat from steam is used as a cold and heat source, in the condensate recovery step, the first steam condensate tank collects steam condensate through the second steam condensate pipe, the third steam condensate pipe, and the fifth steam condensate pipe, part of the condensate is transported to the preheating section of the combined air-conditioning unit via the sixth steam condensate pipe, the cooled condensate enters the second steam condensate tank via the seventh steam condensate pipe, part of the condensate from the second steam condensate tank is provided with cooling water for the cooling and pressure reducing device via the eighth steam condensate pipe and the cooling water pump, and the excess is used by designated systems in the factory.

[0039] The present invention has the following advantages:

[0040] First, high efficiency and energy saving: The present invention makes full use of the abundant steam waste heat in the industrial plant area, avoiding the waste of low-grade thermal energy of steam and its condensed water. Through the steam cascade system and condensed water recovery, the cascade utilization of steam waste heat is realized. For example, the steam condensed water generated by the first process equipment enters the flash tank for flash evaporation, and the generated steam is used for other equipment. The condensed water of the first steam condensed water tank is used for the preheating section of the combined air-conditioning unit, which greatly improves the energy utilization rate. Compared with traditional electric compression refrigeration units or heat pumps, it effectively reduces electricity consumption;

[0041] Second, the environmental benefits are significant: it reduces the thermal pollution to the environment caused by direct steam emissions, and at the same time reduces greenhouse gas emissions caused by power generation. By utilizing waste heat, the overall energy consumption is reduced, and the negative impact on the environment is indirectly reduced, which meets environmental protection requirements.

[0042] Third, the economic benefits are outstanding: the use of surplus low-pressure steam in the factory as the driving heat source instead of electricity avoids the power grid load of the air-conditioning system and saves a lot of electricity costs. The enterprise does not need to invest high costs in the power consumption of refrigeration equipment, which reduces production costs and improves economic benefits.

[0043] Fourth, stable and reliable operation: The DCS control equipment is used to achieve accurate control and monitoring of the operating parameters of each device. By adjusting the steam flow, cold water flow, etc., the system can ensure stable operation under different working conditions. The backup design of the temperature and pressure reduction device, the reasonable configuration of the flash tank and the steam cylinder, improve the reliability of the system.

[0044] Fifth, meet diverse needs: The multifunctional segment design of the combined air conditioning unit can accurately adjust the indoor environment according to the air supply volume, air supply temperature and humidity requirements, indoor environmental temperature and humidity and cleanliness requirements of the process requirements, combined with outdoor meteorological parameters. It provides a stable cold source in summer and a reliable heat source in winter, meeting the needs of different production environments throughout the year. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0046] Figure 1 Schematic diagram of an energy-saving air-conditioning system in which waste heat from steam is used as a cold or hot source in an embodiment of the present invention.

[0047] In the figure, 1, first process equipment; 2, temperature reduction and pressure reduction device; 3, flash tank; 4, steam cylinder; 5, second process equipment; 6, steam-type lithium bromide absorption refrigerator; 7, constant pressure water supply device; 8, combined air conditioning unit; 9, first steam condensate tank; 10, second steam condensate tank; 11, first steam pipeline; 12, second steam pipeline; 13, first steam condensate pipeline; 14, third steam pipeline; 15, second steam condensate pipeline; 16, fourth steam pipeline; 17, The fifth steam pipe; 18. The third steam condensate pipe; 19. The sixth steam pipe; 20. The seventh steam pipe; 21. The eighth steam pipe; 22. The ninth steam pipe; 23. The fourth steam condensate pipe; 24. The first cold water pipe; 25. The cold water circulation pump; 26. The second cold water pipe; 27. The fifth steam condensate pipe; 28. The condensate pump; 29. ​​The sixth steam condensate pipe; 30. The seventh steam condensate pipe; 31. The cooling water pump; 32. The eighth steam condensate pipe. DETAILED DESCRIPTION

[0048] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] See also Figure 1 The embodiment of the present invention provides an energy-saving air-conditioning system that uses waste heat from steam to provide cold and hot sources, including:

[0050] The first process equipment 1, as a medium / high pressure gas-using equipment, is heated by medium / high pressure saturated steam with a design pressure of p2;

[0051] The temperature reduction and pressure reduction device 2 is used to adjust the steam source parameters (p1, t1) to the p2 saturation state. The temperature reduction and pressure reduction device 2 is provided with the temperature reduction water by the second steam condensate tank or the desalted water tank in the plant area. The saturated steam with the pressure of p2 produced by the temperature reduction and pressure reduction device 2 is transported to the first process equipment 1 through the second steam pipeline 12;

[0052] Flash tank 3, used for receiving and separating steam and condensed water with a pressure of p3 generated by flash evaporation of steam after heat exchange in first process equipment 1;

[0053] The steam cylinder 4 is used to receive the steam from the flash tank 3 and the low-pressure steam from the plant area, and to supply steam to the second process equipment 5, the steam-type lithium bromide absorption refrigerator 6, and the combined air conditioning unit 8;

[0054] 6 sets of steam-type lithium bromide absorption refrigeration machines, equipped with a cold water circulation pump 25 and a constant pressure water supply device 7, are used to provide cold water for the combined air conditioning unit 8 in summer;

[0055] Combined air conditioning unit 8, including a fresh air section, a mixed air section, a preheating section, a heating section, a surface cooling section, a spray section, a dry steam humidification section, and a blower section;

[0056] The steam condensate tank includes a first steam condensate tank 9 and a second steam condensate tank 10, which are used to collect the steam condensate of the system;

[0057] DCS control equipment is used to control and monitor system operating parameters.

[0058] In this embodiment, the temperature reduction and pressure reduction device 2 includes two processes of pressure reduction and temperature reduction. The temperature reduction water is obtained from the second steam condensate water tank in the plant area by the temperature reduction water pump 31 through the eighth steam condensate water pipeline 32, or obtained from the desalted water tank in the plant area;

[0059] The temperature and pressure reduction device 2 adjusts the steam source transported via the first steam pipeline from the pressure p1 state to the saturated state p2;

[0060] The design pressure of the flash tank 3 is p3, and the flash tank 3 receives the steam condensate generated by the first process equipment 1 through the first steam condensate pipeline 13.

[0061] In this embodiment, the first process equipment 1 is mainly medium / high pressure gas equipment such as steam heat setting or ovens. For normal production and operation, medium pressure saturated steam with a design pressure of p2 = 2.5 MPa needs to be used for heating through steam jacketed pipes or coils.

[0062] In this embodiment, according to the stable operation requirements of the process production, the medium-pressure saturated steam flow rate of p2=2.5MPa required by the first process equipment 1 is 15.6t / h, and the pipe diameter is DN125. The heat load is calculated by the product of the steam mass flow rate and the steam specific enthalpy. When the steam source design pressure provided by the steam turbine exhaust / exhaust of the small and medium-sized thermal power station in the plant area or the municipal steam pipeline network in the park is p1=4.0Mpa, and the design temperature is t1=400℃ of superheated steam. When p1<p2, the equipment use pressure requirements of the first process equipment 1 are not met; usually the steam source supply pressure will not be exactly equal to the use design pressure of a certain user-end equipment. Therefore, p1>p2, at this time p1=4.0MPa exceeds the equipment design pressure bearing capacity of the first process equipment 1, and the temperature reduction and pressure reduction device 2 can be used to adjust the steam parameters from (p1=4.0MPa, t1=400℃) to p2=2.5MPa saturated state to meet the needs of the first process equipment 1.

[0063] In this embodiment, the temperature reduction and pressure reduction device 2 includes two processes: pressure reduction and temperature reduction. The pressure reduction process is achieved by a pressure reducing valve, and the temperature reduction process is achieved by spraying atomized temperature reduction water at a nozzle in the desuperheater. The temperature reduction water can be provided by the second steam condensate water tank in the plant area, or by a desalted water tank in the plant area according to actual operation conditions, and is transported to the temperature reduction and pressure reduction device 2 by a temperature reduction water pump 31.

[0064] Among them, the temperature reduction and pressure reduction device 2 is a plant steam heat source used all year round, and one standby is set, and it should be in hot standby state. According to the operation requirements, the change of the steam flow rate at the outlet of the temperature reduction and pressure reduction device 2 needs to be accurately adjusted within a certain range. The second steam pipeline 12 thereafter is not only provided with a local pressure gauge and a thermometer for on-site indication, but also with a pressure transmitter and a temperature transmitter with remote indication function. The signal is remotely transmitted and fed back to the DCS control device, and the alarm and adjustment functions are realized on the DCS control device. The opening of the cooling water flow regulating valve of the eighth steam condensate water pipeline 32 is controlled by the remote temperature indication signal of the temperature transmitter to realize the regulation of the cooling water flow. For example, the remote temperature indication signal of the temperature transmitter is set to a high alarm of 260°C. When the alarm signal is issued, the opening of the cooling water flow regulating valve of the eighth steam condensate water pipeline 32 is increased to realize the regulation of the cooling water flow. The throttling area of ​​the pressure reducing valve is controlled by the remote indication pressure signal of the pressure transmitter to realize the pressure regulation of the pressure reduction process. For example, if the remote indication pressure signal of the pressure transmitter is set to a 2.6MPa high-level alarm, when the alarm signal is issued, the throttling area of ​​the pressure reducing valve is increased to achieve pressure regulation during the pressure reduction process.

[0065] In this embodiment, a steam safety valve is provided on the second steam pipeline 12 to ensure that the first process equipment 1 will not be subjected to excessive working pressure, thereby maintaining the safe and stable operation of the first process equipment 1. The first steam pipeline 11 is the pipeline before the temperature and pressure reducer, which comes from the steam extraction / exhaust of the steam turbine of the small and medium-sized thermal power station in the factory area or the municipal steam pipeline network of the park. A flow meter, a temperature transmitter and a pressure transmitter with a remote transmission indication signal function are provided on it, and the signal is remotely transmitted and fed back to the DCS control equipment.

[0066] Among them, after the first process equipment 1 absorbs medium and high steam heat in the steam jacket pipe or coil, the steam condenses in the pipe, releases latent heat in the phase change process, and generates saturated steam condensate with a design pressure of p2 = 2.5 MPa. In order to make full use of the waste heat of this part of steam condensate, it is transported to the flash tank 3 through the first steam condensate pipeline 13.

[0067] In this embodiment, the flash tank 3 is a vertical cylindrical pressure vessel, and the design pressure is p3 = 0.4 MPa, which is the same as the pressure value of the fourth steam pipeline 16. The steam generated by the flash tank 3 and the factory-supplied surplus low-pressure saturated steam of the fourth steam pipeline 16 meet the steam demand of the second process equipment 5, the steam-type lithium bromide absorption refrigeration machine 6, and the heating section of the combined air-conditioning unit 8, etc., which can use low-grade thermal energy.

[0068] Among them, a local pressure gauge and a thermometer are set on the flash tank 3 for on-site indication. A liquid level gauge with a remote indication signal function is set on the side of the tank body, and the signal is remotely transmitted and fed back to the DCS control equipment to realize the high and low alarm of the liquid level on the DCS. When the high liquid level alarm is issued, the liquid should be drained in time. A steam safety valve is set on the upper part of the tank body to ensure that the equipment is not over-pressured and maintain the safe operation of the equipment and the pipeline system. The upper space in the flash tank 3 is the medium-pressure steam in the first process equipment 1. The saturated steam with a design pressure of p3=0.4MPa is obtained, so p3<p2. It is transported to the sub-cylinder 4 through the third steam pipeline 14; the saturated steam condensate with a design pressure of p3=0.4MPa is generated in the lower part, and the flow rate is 3.5t / h. It is transported to the first steam condensate tank 9 through the second steam condensate pipeline 15.

[0069] In this embodiment, the steam cylinder 4 is a horizontal pressure vessel with a design pressure of p3 = 0.4 MPa. According to the number of steam supply sources and output gas ends and the steam flow rate, a plurality of pipe ports are provided on the top of the steam cylinder 4, including an access pipe port and an output pipe port. The pipe port diameter is determined according to the pipe diameter of each branch, and a regulating valve is installed above the pipe port. The steam cylinder 4 can play the role of stabilizing pressure, diverting flow, and regulating flow. A water-draining device and a water-draining device are provided at the bottom of the steam cylinder 44.

[0070] Specifically, there are two steam sources for the steam cylinder 4: one is from the outlet of the third steam pipe 14 of the flash tank 3, with an input steam flow rate of 10.5t / h and a pipe diameter of DN200. The other is the abundant low-pressure steam network in the plant area, which is connected to the outlet of the steam cylinder 4 through the fourth steam pipe 16. The maximum steam flow rate required for the user end of this system must be guaranteed, which is the sum of the maximum flow rate required for the operation of the second process equipment 5 and the summer steam-type lithium bromide refrigeration machine, 23t / h, and the pipe diameter is DN350. The system design gives priority to the use of the 10.5t / h steam generated by the flash tank 3, making full use of the waste heat nearby. The insufficient 12.5t / h is supplemented by the fourth steam pipe 16, thereby ensuring the steam consumption of the system.

[0071] Specifically, there are three main gas output ends of the steam cylinder 4: the fifth steam pipeline 17 supplies the second process equipment 5, with a maximum output flow rate of 2t / h and an interface pipe diameter of DN100; the sixth steam pipeline 19 is a main pipe for the combined air conditioning unit 8, with a maximum output flow rate of 17t / h and an interface pipe diameter of DN300; the ninth steam pipeline 22 supplies the steam type absorption refrigeration unit, with a maximum output flow rate of 21t / h and an interface pipe diameter of DN350. If there are other gas-consuming equipment with the same parameters, the output pipe ports of the steam cylinder 4 can also be increased.

[0072] In this embodiment, the sixth steam pipe 19 is a main pipe for the combined air-conditioning unit 8, which is then divided into two routes. The seventh steam pipe 20 supplies its heating section, and the pipe diameter is DN300; the eighth steam pipe 21 supplies its dry steam humidification section, and the pipe diameter is DN50.

[0073] Among them, the fourth steam pipeline 16 is a low-pressure saturated steam pipeline network with abundant power in the plant area, and the design pressure is p3 = 0.4MPa, which meets the normal production and operation requirements of the second process equipment 5, the steam-type lithium bromide absorption refrigeration machine 6 and the heating section of the combined air-conditioning unit 8, etc. The fourth steam pipeline 16 is provided with a flow meter, a thermometer and a pressure gauge with a remote transmission indication signal function, and the signal is remotely transmitted and fed back to the DCS control equipment.

[0074] In this embodiment, the second process equipment 5 is mainly low-pressure gas equipment such as a steam preheating box and a heating hot water tank. For its normal production operation, it is necessary to use low-pressure saturated steam with a design pressure of p3 = 0.4 MPa for heating through a steam jacket pipe or coil. The maximum flow rate required by the second process equipment 5 is 2 t / h. The required heat load is calculated by multiplying the steam mass flow rate and the steam specific enthalpy.

[0075] In this embodiment, the fourth steam condensate pipeline 23 is saturated or supercooled steam condensate at a pressure of p3 = 0.4 MPa after heat exchange with steam used by the second process equipment 5, and is led to the first steam condensate tank 9.

[0076] In this embodiment, the combined air conditioning unit 8 is an air handling device of a centralized air conditioning system, which is composed of a fresh air section, a mixed air section, a preheating section, a heating section, a surface cooling section, a spray section (whether to set this section is determined according to the requirements of the air supply temperature and humidity), a dry steam humidification section, a blower section, and other functional sections. The fresh air (or the fresh air mixed with the return air) treated by a series of functional sections of the combined air conditioning unit 8 is transported to the indoor air conditioning area through the air conditioning duct by a blower with a certain air volume and air pressure to meet the temperature, humidity, and cleanliness requirements required for the process air conditioning and production environment in the production plant.

[0077] The winter heating load and summer cooling load of the combined air conditioning unit 8 are determined by the air conditioning air supply volume, air supply temperature and humidity requirements, indoor environment temperature and humidity and cleanliness requirements and other parameters required by the process, combined with the outdoor meteorological parameters of the project location, through air conditioning system load calculation. In this embodiment, the maximum steam flow rate for heating demand in winter is 17t / h, and the maximum steam flow rate for cooling demand in summer is 21t / h.

[0078] In this embodiment, the sixth steam pipe 19 is only operated in winter (mid-October to mid-April of the following year) to provide air conditioning heat source for the combined air conditioning unit 8. The seventh steam pipe 20 is connected to the heating section of the combined air conditioning unit 8, and the condensed water generated after heat exchange is connected to the first steam condensed water tank 9 through the fifth steam condensed water pipe 27. The eighth steam pipe 21 is connected to the nozzle of the dry steam humidification section, and the dry steam is fully mixed with the treated air to achieve the humidification function.

[0079] Among them, an ambient temperature transmitter with a remote indication signal is set outdoors, and a flowmeter with a remote indication signal and a steam flow control valve are set on the sixth steam pipe 19. For the air conditioning design parameters determined by the process requirements, the enthalpy value under the outdoor ambient temperature and humidity (cascade main loop) is the main dependent variable of the air conditioning heating load, and the steam flow (cascade sub-loop) on the sixth steam pipe 19 is linearly related to the air conditioning heat load. The combined effect of ambient temperature and humidity (cascade main loop) and steam flow (cascade sub-loop) is used to realize the steam flow control valve opening adjustment of the heating section of the combined air conditioning unit 8 operating in winter on the DCS control device.

[0080] Among them, for the air conditioning design parameters determined by the process requirements, the lower the enthalpy value corresponding to the outdoor air temperature and humidity in winter, the greater the air conditioning heating load, the greater the flow rate of the heat source low-pressure saturated steam required by the heating section of the combined air conditioning unit 8, and the larger the opening of the steam flow regulating valve needs to be adjusted. The same applies in reverse.

[0081] In this embodiment, the ninth steam pipe 22 is only operated in summer (mid-April to mid-October) to provide a driving heat source for the steam-type lithium bromide absorption refrigerator 6 to produce cold water. The steam-type lithium bromide absorption refrigerator 6 is equipped with auxiliary refrigeration system equipment such as a cold water circulation pump 25 and a constant pressure water replenishment device 7 to provide an air conditioning cold source for the combined air conditioning unit 8 operating in summer, and to provide cold water with a rated supply and return water temperature of 7 / 12°C for its surface cooling section. The first cold water pipe 24 is a 12°C return water pipe for the refrigerator; the second cold water pipe 26 is a 7°C supply water pipe for the refrigerator.

[0082] Among them, an ambient temperature transmitter with a remote transmission indication signal is set outdoors, and a flow meter with a remote transmission signal and a cold water flow regulating valve are set on the second cold water pipe 26. For the air conditioning design parameters determined by the process requirements, the enthalpy value under the outdoor ambient temperature and humidity (cascade main loop) is the main dependent variable of the air conditioning cooling load, and the cold water flow (cascade secondary loop) on the second cold water pipe 26 is linearly related to the air conditioning cooling load. The ambient temperature (cascade main loop) and the cold water flow (cascade secondary loop) work together to realize the steam flow regulating valve opening adjustment of 6 groups of steam-type lithium bromide absorption chillers running in summer on the DCS control device.

[0083] Among them, for the air conditioning design parameters determined by the process requirements, the higher the enthalpy value corresponding to the outdoor air temperature and humidity in summer, the greater the air conditioning cooling load, the greater the cold water flow rate required to be provided by the steam-type lithium bromide absorption chiller 6 groups 6, the greater the flow rate of the required driving heat source low-pressure saturated steam, and the larger the opening of the steam flow regulating valve. The same applies in reverse.

[0084] In this embodiment, the fourth steam condensate pipe 23 leads the saturated or supercooled steam condensate under the pressure of p3 = 0.4MPa used by the steam type lithium bromide absorption refrigeration machine 6 group to the first steam condensate tank 9. The first steam condensate tank 9 is used to collect the steam condensate generated by the flash tank 3, the second process equipment 5, the steam type lithium bromide absorption refrigeration machine 6 group and the heating section of the combined air conditioning unit 8 after heat exchange. The condensate temperature in the tank is 90-100°C. An on-site thermometer is set on the tank body for on-site indication.

[0085] In order to fully realize the cascade utilization of steam waste heat, the high-temperature steam condensate in the first steam condensate tank 9 is transported to the preheating section of the combined air conditioning unit 8 through the sixth steam condensate pipeline 29 and the matching condensate pump 28. The heat exchange process fully utilizes the heat of the high-temperature condensate to preheat the fresh air (or the mixture of fresh air and return air) from the outside. The cooled steam condensate is transported to the second steam condensate tank 10 through the seventh steam condensate pipeline 30.

[0086] In this embodiment, the second steam condensate tank 10 is used to collect the steam condensate after sufficient cooling. A local thermometer is set on the tank body for on-site indication. The eighth steam condensate pipeline 32 is matched with a desuperheating water pump 31 to provide a desuperheating water source for the desuperheating and pressure reducing device 2, and the excess part can also be used by the production device. The water temperature is determined according to the heat exchange calculation of the preheating section of the combined air conditioning unit 8.

[0087] In a possible embodiment, the first steam condensate tank 9 and the second steam condensate tank 10 are provided with vent holes at the top, and are normal pressure open water tanks. An overflow port is provided at the upper part of the side wall of the tank body, and a drain port is provided at the bottom. Insulation material is provided on the outer surface of the tank body, and the insulation material is a rock wool board or an aluminum silicate board, and the outer protective layer of the insulation material is an aluminum plate or a galvanized steel plate.

[0088] In a possible embodiment, the first steam condensate tank 9 and the second steam condensate tank 10 can not only collect the steam condensate of the system, but also collect the steam condensate of the same nature from other systems in the plant nearby.

[0089] The embodiment of the present invention further provides an operation method of an energy-saving air-conditioning system using waste steam heat as a cold and hot source, which is applied to the energy-saving air-conditioning system using waste steam heat as a cold and hot source in the above embodiment, and includes the following steps:

[0090] Steam pretreatment: The steam source is processed by the temperature reduction and pressure reduction device 2 and then sent to the first process equipment 1, so that the steam meets the use requirements of the first process equipment 1;

[0091] Steam flashing and distribution: The steam condensate generated by the first process equipment 1 enters the flash tank 3 for flashing, and the steam generated by the flashing and the low-pressure steam in the plant area are distributed to the second process equipment 5, the steam-type lithium bromide absorption refrigerator 6, and the combined air conditioning unit 8 through the steam distribution cylinder 4;

[0092] Summer cooling: Steam-type lithium bromide absorption refrigeration machine 6 uses the steam provided by the sub-cylinder 4 to produce cold water to provide cooling for the combined air conditioning unit 8;

[0093] Winter heating: The steam from the cylinder 4 provides heat for the combined air conditioning unit 8;

[0094] Condensate recovery: The steam condensate generated by the system is collected in the first steam condensate tank 9 and the second steam condensate tank 10 and recycled.

[0095] In this embodiment, in the steam pretreatment step, when the steam source parameter p1>p2, the pressure reducing valve of the temperature reduction and pressure reduction device 2 reduces the pressure, and the cooling water is obtained from the second steam condensate tank or the desalted water tank in the plant area by the temperature reduction water pump 31. After being cooled by the desuperheater, the steam reaches a saturated state, and the instrument on the second steam pipe 12 feeds back the signal to the DCS control equipment for adjusting the steam parameters.

[0096] Specifically, in industrial production, the pressure and temperature of the steam source often cannot directly meet the needs of the first process equipment 1. When p1>p2, excessive pressure may damage the first process equipment 1, so it is necessary to reduce the steam pressure through a pressure reducing valve. The role of cooling water is to further adjust the temperature of the steam after decompression so that it reaches the saturated state required by the first process equipment 1. Obtaining cooling water from the second steam condensate tank or the desalted water tank in the plant area not only utilizes the water resources in the system, but also ensures the quality of cooling water. The instruments (such as pressure transmitters, temperature transmitters, etc.) on the second steam pipeline 12 monitor the pressure and temperature and other parameters of the steam in real time, and feed these signals back to the DCS control device. The DCS control device adjusts the opening of the cooling water flow regulating valve and the pressure reducing valve according to the preset parameter range to achieve precise adjustment of the steam parameters, ensure that the steam entering the first process equipment 1 is stable, safe and meets the process requirements, and avoid adverse effects on production due to unstable steam parameters.

[0097] In this embodiment, in the steam flashing and distribution step, the flash tank 3 receives and separates the steam condensate of the first process equipment 1 through the first steam condensate pipe 13, the steam generated by the flashing enters the steam cylinder 4 through the third steam pipe 14, and the low-pressure steam of the plant enters the steam cylinder 4 through the fourth steam pipe 16. The steam cylinder 4 distributes the steam through the regulating valve according to the equipment requirements, and the liquid level gauge of the flash tank 3 feeds back the liquid level signal to the DCS control equipment.

[0098] Specifically, after the first process equipment 1 uses steam for heating and other process processes, the steam will condense into water, and these steam condensed water contains a certain amount of energy. After it is introduced into the flash tank 3, due to the low pressure in the flash tank 3 (the design pressure is p3), part of the steam condensed water will flash into steam, realizing the reuse of energy. The steam generated by flash evaporation and the low-pressure steam in the plant area all enter the sub-cylinder 4, which plays the role of centrally distributing steam. The sub-cylinder 4 accurately controls the steam flow rate through the regulating valve according to the real-time steam demand of different equipment such as the second process equipment 5, the steam-type lithium bromide absorption refrigeration machine 6, and the combined air-conditioning unit 8, so as to realize the reasonable distribution of steam. The liquid level gauge of the flash tank 3 monitors the liquid level in the tank in real time. If the liquid level is too high, it may affect the flash evaporation effect, and even cause the steam to carry water, affecting the operation of subsequent equipment. After the liquid level signal is fed back to the DCS control device, the DCS control device can adjust the relevant valves in time according to the liquid level situation, control the flow of the first steam condensate pipeline 13, and ensure the stable operation of the flash tank 3.

[0099] In this embodiment, in the summer cooling step, the steam-type lithium bromide absorption refrigerator group 6 generates 7 / 12°C cold water, which is transported to the combined air-conditioning unit 8 through the first cold water pipe 24, the cold water circulation pump 25, and the second cold water pipe 26. The steam condensate generated by the steam-type lithium bromide absorption refrigerator group 6 enters the first steam condensate tank 9 through the fourth steam condensate pipe 23. The outdoor ambient temperature and humidity and the cold water flow signal of the second cold water pipe 26 are fed back to the DCS control device for adjusting the opening of the steam flow regulating valve of the steam-type lithium bromide absorption refrigerator group 6.

[0100] Specifically, in summer, indoor refrigeration is required to meet the temperature and humidity requirements of the production environment. The steam-type lithium bromide absorption refrigeration machine 6 group uses steam as a driving heat source to produce 7 / 12°C cold water through the absorption refrigeration cycle principle. The cold water is transported to the surface cooling section of the combined air-conditioning unit 8 through the first cold water pipe 24 and the second cold water pipe 26 through the cold water circulation pump 25, and heat exchanges with the hot air to reduce the air temperature and dehumidify, thereby achieving indoor refrigeration. During the refrigeration process, the steam-type lithium bromide absorption refrigeration machine 6 group consumes steam to produce cold water, and steam condensed water is produced. These condensed waters enter the first steam condensed water tank 9 through the fourth steam condensed water pipe 23 for recycling. The outdoor environmental temperature and humidity and the cold water flow rate of the second cold water pipe 26 are key factors affecting the refrigeration demand. Changes in the outdoor environmental temperature and humidity will cause changes in the indoor refrigeration load, and the cold water flow rate of the second cold water pipe 26 reflects the actual demand for cooling capacity. After these two signals are fed back to the DCS control device, the DCS control device adjusts the opening of the steam flow control valve of the six steam-type lithium bromide absorption chillers according to the preset control strategy, thereby adjusting the amount of steam entering the unit to achieve an accurate match between the cooling capacity and actual demand, ensuring the cooling effect while improving energy efficiency.

[0101] In this embodiment, in the winter heating step, the steam of the steam cylinder 4 enters the combined air-conditioning unit 8 through the sixth steam pipe 19, and the condensed water of the first steam condensate tank 9 is transported to the preheating section of the combined air-conditioning unit 8 through the sixth steam condensate pipe 29 and the condensate pump 28. The outdoor ambient temperature and humidity and the steam flow signal of the sixth steam pipe 19 are fed back to the DCS control device for adjusting the opening of the steam flow regulating valve of the heating section of the combined air-conditioning unit 8.

[0102] Specifically, in winter, indoor heating is required to maintain a suitable temperature and humidity. The steam cylinder 4 transports steam to the combined air conditioning unit 8 through the sixth steam pipe 19 to provide heat for the room. The condensed water in the first steam condensate tank 9 has a high temperature and has a certain amount of waste heat. It is transported to the preheating section of the combined air conditioning unit 8 through the condensate pump 28, and this part of the waste heat is used to preliminarily heat the fresh air or mixed air entering the air conditioning unit to improve energy utilization. Changes in outdoor environmental temperature and humidity will affect the indoor heating demand, and the steam flow of the sixth steam pipe 19 reflects the current heating capacity. After these two signals are fed back to the DCS control device, the DCS control device adjusts the opening of the steam flow regulating valve of the heating section of the combined air conditioning unit 8 according to the preset control logic. When the outdoor temperature decreases or the humidity changes, resulting in an increase in the heating demand, the DCS control device increases the opening of the steam flow regulating valve, increases the amount of steam entering, and improves the heating capacity; otherwise, the opening is reduced to achieve precise control of the heating system, ensure stable and comfortable indoor temperature, and avoid energy waste.

[0103] In this embodiment, in the condensate recovery step, the first steam condensate tank 9 collects steam condensate through the second steam condensate pipe 15, the third steam condensate pipe 18, and the fifth steam condensate pipe 27, and part of the condensate is transported to the preheating section of the combined air-conditioning unit 8 through the sixth steam condensate pipe 29. The cooled condensate enters the second steam condensate tank 10 through the seventh steam condensate pipe 30. Part of the condensate in the second steam condensate tank 10 is provided with cooling water for the cooling and pressure reducing device 2 through the eighth steam condensate pipe 32 and the cooling water pump 31, and the excess is used by the designated system in the factory.

[0104] Specifically, steam will condense into water after passing through various equipment for heat exchange in the system. These condensed waters contain a certain amount of heat and a relatively high degree of purity. The first steam condensate tank 9 collects steam condensate generated by the flash tank 3, the second process equipment 5, the combined air-conditioning unit 8 and other equipment through multiple pipelines to realize the centralized recovery of condensate. Part of the condensate is transported to the preheating section of the combined air-conditioning unit 8 to preheat the air using the waste heat of the condensate to improve energy efficiency. After heat exchange in the preheating section, the temperature of the condensate is reduced and enters the second steam condensate tank 10. Part of the condensate in the second steam condensate tank 10 is used to provide cooling water for the cooling and pressure reducing device 2, which not only utilizes the water resources of the condensate, but also utilizes its lower temperature to realize the cooling function of the steam. The excess condensate can be used by designated systems in the plant area, such as other process links that require water, to realize the recycling of water resources, reduce the waste of water resources, and reduce the operating costs of the enterprise.

[0105] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. An energy-saving air conditioning system using waste heat from steam as a cold or hot source, characterized in that: include: The first process equipment (1), as a medium / high pressure gas-using equipment, is heated by medium / high pressure saturated steam with a design pressure of p2; A temperature reduction and pressure reduction device (2) is used to adjust a steam source with a pressure of p1 to a saturated state of p2, wherein the temperature reduction and pressure reduction device (2) uses a second steam condensate tank (10) or a desalted water tank in the plant area to provide the temperature reduction and pressure reduction device (2). The saturated steam with a pressure of p2 produced by the temperature reduction and pressure reduction device (2) is transported to the first process equipment (1) via a second steam pipeline (12); A flash tank (3) is used to receive and separate saturated steam and condensed water at a pressure of p3 generated by flash evaporation of steam after heat exchange in the first process equipment (1); The steam cylinder (4) is used to receive steam from the flash tank (3) and low-pressure steam from the plant area, and to supply steam to the second process equipment (5), the steam-type lithium bromide absorption refrigeration unit (6), and the combined air conditioning unit (8); A steam-type lithium bromide absorption refrigeration unit (6) is provided with a cold water circulation pump (25) and a constant pressure water supply device (7) for providing cold water for a combined air conditioning unit (8) in summer; A combined air conditioning unit (8), comprising a fresh air section, a mixed air section, a preheating section, a heating section, a surface cooling section, a spray section, a dry steam humidification section, and a blower section; A steam condensate tank, comprising a first steam condensate tank (9) and a second steam condensate tank (10), for collecting system steam condensate; DCS control equipment is used to control and monitor system operating parameters.

2. The energy-saving air-conditioning system according to claim 1, wherein the heat source is provided by steam waste heat. The temperature reduction and pressure reduction device (2) includes two processes: pressure reduction and temperature reduction. The temperature reduction water is obtained from the second steam condensate water tank (10) in the plant area by a temperature reduction water pump (31) through an eighth steam condensate water pipeline (32), or is obtained from a desalted water tank in the plant area; The temperature and pressure reduction device (2) adjusts the steam source from a pressure state of p1 to a saturated state of p2 via a first steam pipeline (11); The design pressure of the flash tank (3) is p3, and the flash tank (3) receives steam condensate generated by the first process equipment (1) through a first steam condensate pipeline (13).

3. The energy-saving air-conditioning system according to claim 1, wherein the heat source is provided by waste heat of steam. The steam supply source for the steam cylinder (4) includes saturated steam with a pressure of p3 generated from the flash tank (3) via the third steam pipeline (14), and saturated steam with a pressure of p3 from the surplus low-pressure steam network in the plant area via the fourth steam pipeline (16). The output gas end of the steam cylinder (4) is connected to the second process equipment (5), the steam-type lithium bromide absorption refrigeration unit (6) and the combined air conditioning unit (8) through a fifth steam pipeline (17), a ninth steam pipeline (22) and a sixth steam pipeline (19) respectively.

4. The energy-saving air-conditioning system according to claim 3, wherein the heat source is provided by steam waste heat. When the steam-type lithium bromide absorption refrigeration unit (6) is operated in summer, it provides 7 / 12°C cold water to the combined air conditioning unit (8) through the first cold water pipeline (24), the cold water circulation pump (25), and the second cold water pipeline (26).

5. The energy-saving air-conditioning system using waste heat from steam as a cold and hot source according to claim 1, characterized in that: The winter heating load and summer cooling load of the combined air conditioning unit (8) are determined by air conditioning system load calculation based on the air conditioning air supply volume, air supply temperature and humidity requirements, indoor environmental temperature and humidity and cleanliness requirements required by the process, and combined with the outdoor meteorological parameters of the project location.

6. The energy-saving air conditioning system using waste heat from steam as a cold and hot source according to claim 1, characterized in that: The first steam condensate tank (9) collects the steam condensate generated by the flash tank (3) through the second steam condensate pipe (15); the first steam condensate tank (9) collects the steam condensate generated by the second process equipment (5) through the third steam condensate pipe (18); the first steam condensate tank (9) collects the steam condensate generated by the combined air conditioning unit (8) through the fifth steam condensate pipe (27); The steam-type lithium bromide absorption refrigeration unit (6) introduces saturated or supercooled steam condensate at the steam pressure p3 used by the steam-type lithium bromide absorption refrigeration unit (6) to the first steam condensate tank (9) through a fourth steam condensate pipeline (23); Part of the condensed water in the first steam condensed water tank (9) is transported to the preheating section of the combined air-conditioning unit (8) through the sixth steam condensed water pipeline (29) by means of a condensed water pump (28) to utilize the waste heat, and the steam condensed water after cooling of the combined air-conditioning unit (8) enters the second steam condensed water tank (10) through the seventh steam condensed water pipeline (30); The first steam condensate tank (9) and the second steam condensate tank (10) are both provided with ventilation holes at the top, and the first steam condensate tank (9) and the second steam condensate tank (10) are both open water tanks at normal pressure. Overflow ports are provided at the upper part of the side walls of the first steam condensate tank (9) and the second steam condensate tank (10), and drain ports are provided at the bottom. Insulation materials are provided on the outer surface of the tank, and steam condensate with the same properties as those of the designated system in the plant is collected.

7. The energy-saving air conditioning system using steam waste heat as a cold and hot source according to claim 4, characterized in that: An ambient temperature transmitter with a remote indication signal is arranged outdoors, a flow meter with a remote indication signal and a steam flow regulating valve are arranged on the sixth steam pipeline (19), and the opening of the steam flow regulating valve of the heating section of the combined air conditioning unit (8) operating in winter is adjusted on the DCS control device through the combined action of the outdoor ambient temperature and humidity and the steam flow; A flow meter with a remote signal transmission and a cold water flow regulating valve are arranged on the second cold water pipeline (26), and the opening of the steam flow regulating valve of the steam-type lithium bromide absorption refrigeration unit (6) operating in summer is adjusted on the DCS control device through the combined effect of the outdoor environment temperature and humidity and the cold water flow.

8. An operating method of an energy-saving air-conditioning system using waste steam heat as a cold or hot source, applied to the energy-saving air-conditioning system using waste steam heat as a cold or hot source as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: Steam pretreatment: the steam source is processed by the temperature reduction and pressure reduction device (2) and then sent to the first process equipment (1), so that the steam meets the use requirements of the first process equipment (1); Steam flashing and distribution: the steam condensate generated by the first process equipment (1) enters the flash tank (3) for flashing, and the steam generated by the flashing and the low-pressure steam of the plant area are distributed to the second process equipment (5), the steam-type lithium bromide absorption refrigeration unit (6), and the combined air conditioning unit (8) through the steam distribution cylinder (4); Summer cooling: The steam-type lithium bromide absorption refrigeration unit (6) uses the steam provided by the sub-cylinder (4) to generate cold water to provide cooling for the combined air conditioning unit (8); Winter heating: The steam from the steam cylinder (4) provides heat for the combined air conditioning unit (8); Condensate recovery: The steam condensate generated by the system is collected in the first steam condensate tank (9) and the second steam condensate tank (10) and recycled.

9. The method for operating an energy-saving air-conditioning system using waste steam heat as a cold and hot source according to claim 8, characterized in that: In the steam pretreatment step, when the steam source parameter p1>p2, the pressure reducing valve of the temperature reduction and pressure reducing device (2) reduces the pressure, and the temperature reducing water is obtained from the second steam condensate water tank (10) or the desalted water tank in the plant area by the temperature reducing water pump (31). After the temperature is reduced by the desuperheater, the steam reaches a saturated state, and the instrument on the second steam pipeline (12) feeds back the signal to the DCS control device for adjusting the steam parameters; In the steam flashing and distribution step, the flash tank (3) receives and separates the steam condensate of the first process equipment (1) through the first steam condensate pipe (13), the steam generated by the flashing enters the steam cylinder (4) through the third steam pipe (14), the low-pressure steam of the plant enters the steam cylinder (4) through the fourth steam pipe (16), the steam cylinder (4) distributes the steam through the regulating valve according to the equipment requirements, and the liquid level gauge of the flash tank (3) feeds back the liquid level signal to the DCS control equipment.

10. The operating method of an energy-saving air-conditioning system using waste heat from steam as a cold or hot source according to claim 9, characterized in that: In the summer cooling step, the steam-type lithium bromide absorption refrigeration unit (6) generates cold water at 7 / 12°C, which is transported to the combined air conditioning unit (8) via the first cold water pipeline (24), the cold water circulation pump (25), and the second cold water pipeline (26); the steam condensed water generated by the steam-type lithium bromide absorption refrigeration unit (6) enters the first steam condensed water tank (9) via the fourth steam condensed water pipeline (23); the outdoor environment temperature and humidity and the cold water flow signal of the second cold water pipeline (26) are fed back to the DCS control device for adjusting the opening of the steam flow regulating valve of the steam-type lithium bromide absorption refrigeration unit (6); In the winter heating step, the steam of the steam cylinder (4) enters the combined air conditioning unit (8) through the sixth steam pipe (19), the condensed water of the first steam condensed water tank (9) is transported to the preheating section of the combined air conditioning unit (8) through the sixth steam condensed water pipe (29) and the condensed water pump (28), and the outdoor environment temperature and humidity and the steam flow signal of the sixth steam pipe (19) are fed back to the DCS control device for adjusting the opening of the steam flow regulating valve of the heating section of the combined air conditioning unit (8); In the condensate recovery step, the first steam condensate tank (9) collects steam condensate through the second steam condensate pipe (15), the third steam condensate pipe (18), and the fifth steam condensate pipe (27), and part of the condensate is transported to the preheating section of the combined air-conditioning unit (8) through the sixth steam condensate pipe (29). The cooled condensate enters the second steam condensate tank (10) through the seventh steam condensate pipe (30). Part of the condensate in the second steam condensate tank (10) is supplied to the cooling and pressure reducing device (2) through the eighth steam condensate pipe (32) and the cooling water pump (31), and the excess is used by the designated system in the plant.

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