Printing workshop waste heat recycling system

Abstract

The utility model discloses a printing workshop waste heat recycling system which comprises a heat storage water tank which is provided with a water supplementing pipeline. The first circulating water return pipe, the second circulating water return pipe, the third circulating water outlet pipe and the fourth circulating water outlet pipe are located on the upper portion, and the first circulating water outlet pipe, the second circulating water outlet pipe, the third circulating water return pipe and the fourth circulating water return pipe are located on the lower portion. The heat storage water tank is connected with the RTO waste gas treatment device, the air compressor waste heat recovery device, the heat conduction oil oven waste heat utilization unit and the air conditioning unit through pipelines. The device is small in occupied area, low in investment and convenient to adjust, RTO catalytic combustion waste heat and air compressor waste heat of a printing workshop are transferred to a workshop air conditioning system and a heat conduction oil system in a heat storage mode of the heat preservation water tank, comprehensive utilization of heat is achieved, waste of the RTO catalytic combustion heat and the air compressor waste heat is avoided, and the environment is protected. And moreover, the purposes of energy conservation and consumption reduction of printing enterprises are achieved, and the method has important significance for reducing carbon emission.

Description

Technical Field

[0001] The utility model relates to the technical field of waste heat recovery, in particular to a waste heat recovery and utilization system for a printing workshop. Background Art

[0002] Traditional printing production belongs to high energy consumption and high pollution industry. Due to the use and volatilization of ink, cleaning agent and adhesive, a large amount of VOCs organic waste gas will be generated. In order to decompose the harmful substances in the waste gas, the RTO catalytic combustion method is usually used to convert them into carbon dioxide and water to achieve waste gas purification. Secondly, the printing workshop needs compressed air for spraying during the printing production process. The compressed air is produced by the air compressor. The air compressor will generate a lot of heat in the process of producing compressed air. Thirdly, in order to ensure the printing quality, the printing workshop needs a constant temperature and humidity air-conditioned environment. In winter, the air-conditioning system needs to send a large amount of fresh air to the workshop to supplement the workshop exhaust, and the fresh air will consume a lot of heat energy. Finally, gravure printing machines often use ovens to quickly dry the printed ink. The principle is that the thermal oil heating system (such as natural gas combustion, electric heating, etc.) heats the thermal oil, and then sends the thermal oil to the furnace body through the oil pump to heat the air. The high-temperature air takes away the ink that remains undried after printing, achieving rapid drying. The thermal oil oven consumes a lot of energy during the production process throughout the year. Summary of the invention

[0003] In order to achieve energy saving and consumption reduction, the utility model provides a waste heat recovery and utilization system for a printing workshop, which can specifically adopt the following technical solutions:

[0004] The printing workshop waste heat recovery and utilization system described in the utility model comprises:

[0005] A hot water storage tank, wherein the hot water storage tank is provided with a water supply pipe, and is also provided with a first circulation return pipe, a second circulation return pipe, a third circulation outlet pipe, and a fourth circulation outlet pipe located at the upper portion, and a first circulation outlet pipe, a second circulation outlet pipe, a third circulation return pipe, and a fourth circulation return pipe located at the lower portion;

[0006] An RTO waste gas treatment device, wherein the inlet end of the RTO waste gas treatment device is connected to the workshop exhaust duct, and the outlet end is connected to the chimney through a smoke exhaust duct, and a first branch pipe and a second branch pipe are arranged in parallel on the smoke exhaust duct, the first branch pipe is provided with a first air valve, and the second branch pipe is provided with a second air valve and a flue gas-water heat exchanger, and the flue gas-water heat exchanger is connected to the first circulating water outlet pipe and the first circulating water return pipe;

[0007] An air compressor waste heat recovery device, the air compressor waste heat recovery device comprises an air compressor, an air compressor waste heat recovery heat exchanger and a cooling tower, a high-temperature oil supply pipe and a low-temperature oil return pipe are arranged between the air compressor and the air compressor waste heat recovery heat exchanger, a cooling water supply pipe and a cooling water return pipe are arranged between the air compressor waste heat recovery heat exchanger and the cooling tower, and the air compressor waste heat recovery heat exchanger and the hot water storage tank are connected through the second circulation outlet pipe and the second circulation return pipe;

[0008] A thermal oil oven waste heat utilization unit, the thermal oil oven waste heat utilization unit comprises a thermal oil oven, a thermal oil high-position constant-pressure expansion tank, and a high-temperature heat pump unit. A thermal oil supply pipe and a thermal oil return pipe are arranged between the thermal oil oven and the condenser of the high-temperature heat pump unit. The thermal oil high-position constant-pressure expansion tank is connected to the thermal oil supply pipe / the thermal oil return pipe through the thermal oil constant-pressure expansion pipe. The evaporator and the hot water storage tank of the high-temperature heat pump unit are connected to the third circulation water outlet pipe and the third circulation water return pipe.

[0009] The air conditioning unit is connected to the hot water storage tank via the fourth circulating water outlet pipe and the fourth circulating water return pipe.

[0010] The first circulation water outlet pipe or the first circulation water return pipe is provided with a flue gas waste heat recovery circulation pump, the second circulation water outlet pipe or the second circulation water return pipe is provided with an air compressor waste heat recovery circulation pump, the cooling water supply pipe or the cooling water return pipe is provided with a cooling water circulation pump, the third circulation water outlet pipe or the third circulation water return pipe is provided with a hot water circulation pump for a thermal oil oven, the thermal oil supply pipe or the thermal oil return pipe is provided with a thermal oil circulation pump, and the fourth circulation water outlet pipe or the fourth circulation water return pipe is provided with a hot water circulation pump for an air conditioner.

[0011] A third butterfly valve is arranged on the heat transfer oil supply pipe or the heat transfer oil return pipe.

[0012] The air conditioning unit is provided with a fresh air valve and a return air valve, and the fourth circulation water outlet pipe or the fourth circulation water return pipe is provided with a fourth butterfly valve.

[0013] The air compressor waste heat recovery device, the thermal oil drying oven and the air conditioning unit are arranged in parallel in two or more sets.

[0014] The printing workshop waste heat recovery and utilization system provided by the utility model occupies a small area, requires little investment, and is easy to adjust. It transfers the RTO catalytic combustion waste heat and air compressor waste heat of the printing workshop to the workshop air-conditioning system and heat transfer oil system by storing heat in an insulated water tank, thereby realizing the comprehensive utilization of heat. It not only avoids the waste of RTO catalytic combustion heat and air compressor waste heat, but also achieves the purpose of energy saving and consumption reduction in printing enterprises, which is of great significance for reducing carbon emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the utility model. DETAILED DESCRIPTION

[0016] The following is a detailed description of an embodiment of the utility model in conjunction with the accompanying drawings. This embodiment is implemented on the premise of the technical solution of the utility model, and a detailed implementation method and a specific working process are given, but the protection scope of the utility model is not limited to the following embodiment.

[0017] like Figure 1 As shown, the waste heat recovery system of the printing workshop described in the utility model is composed of a heat storage tank 1, an RTO waste gas treatment device 2, an air compressor waste heat recovery device, a thermal oil oven waste heat utilization unit and an air conditioning unit. The details are as follows:

[0018] The hot water storage tank 1 is provided with a constant pressure water supply pipe 11, and a first circulation return pipe 12, a second circulation return pipe 13, a third circulation outlet pipe 14, a fourth circulation outlet pipe 15 located at the upper part and a first circulation outlet pipe 16, a second circulation outlet pipe 17, a third circulation return pipe 18, and a fourth circulation return pipe 19 located at the lower part.

[0019] The inlet end of the RTO waste gas treatment device 2 is connected to the workshop exhaust duct, and the outlet end is connected to the chimney 21 through the exhaust duct. The exhaust duct is provided with a first branch pipe and a second branch pipe in parallel. The first branch pipe is provided with a first air valve 22 (using an electric valve), and the second branch pipe is provided with a second air valve 23 (using an electric valve) and a flue gas-water heat exchanger 24. The flue gas-water heat exchanger 24 is connected to the first circulation outlet pipe 16 and the first circulation return pipe 12. The first circulation outlet pipe 16 is provided with a flue gas waste heat recovery circulation pump 25, and the flue gas waste heat recovery circulation pump 25 can also be provided on the first circulation return pipe 12.

[0020] The air compressor waste heat recovery device includes an air compressor 31, an air compressor waste heat recovery heat exchanger 32 and a cooling tower 33. A high-temperature oil supply pipe 34 and a low-temperature oil return pipe 35 are arranged between the air compressor 31 and the air compressor waste heat recovery heat exchanger 32. A cooling water supply pipe 36 and a cooling water return pipe 37 are arranged between the air compressor waste heat recovery heat exchanger 32 and the cooling tower 33. A cooling water circulation pump 38 is arranged on the cooling water supply pipe 36 or the cooling water return pipe 37. The air compressor waste heat recovery heat exchanger 32 and the hot water storage tank 1 are connected through the second circulation outlet pipe 17 and the second circulation return pipe 13; the second circulation outlet pipe 17 or the second circulation return pipe 13 is provided with an air compressor waste heat recovery circulation pump 39. Two or more sets of the above-mentioned air compressor waste heat recovery devices are arranged in parallel.

[0021] The thermal oil oven waste heat utilization unit includes a thermal oil oven 41, a thermal oil high-position constant-pressure expansion tank 42, and a high-temperature heat pump unit 43, wherein a thermal oil supply pipe 44 and a thermal oil return pipe 45 are arranged between the thermal oil oven 41 and the condenser of the high-temperature heat pump unit 43, a thermal oil supply pipe 44 or a thermal oil return pipe 45 is arranged on the thermal oil supply pipe 44 or the thermal oil return pipe 45 A thermal oil circulation pump 46 is arranged on the thermal oil supply pipe 44 or the thermal oil return pipe 45 is arranged on the third butterfly valve 47, the thermal oil high-position constant-pressure expansion tank 42 is connected to the thermal oil supply pipe 44 or the thermal oil return pipe 45 through a thermal oil constant-pressure expansion pipe 48, the evaporator of the high-temperature heat pump unit 43 and the hot water storage tank 1 are connected through a third circulation outlet pipe 14 and a third circulation return pipe 18, and a hot water circulation pump 49 for the thermal oil oven is arranged on the third circulation outlet pipe 14 or the third circulation return pipe 18. Two or more thermal oil drying ovens 41 are arranged in parallel.

[0022] The air conditioning unit 51 and the hot water storage tank 1 are connected via the fourth circulation water outlet pipe 15 and the fourth circulation water return pipe 19. A fresh air valve 52 and a return air valve 53 are provided on the air conditioning unit 5. A hot water circulation pump 54 for air conditioning is provided on the fourth circulation water outlet pipe 15 or the fourth circulation water return pipe 19. A fourth butterfly valve 55 is also provided on the fourth circulation water outlet pipe 15 or the fourth circulation water return pipe 19. Two or more sets of the air conditioning units 5 are provided in parallel.

[0023] The working principle of the utility model is as follows:

[0024] 1) For the heat storage unit of the insulated water tank 1: The purpose of setting up the insulated water tank 1 is to store heat for a certain period of time and solve the problem of waste heat recovery and heat use imbalance. The waste heat is stored in the hot water storage tank 1 in the form of high-temperature hot water, and the constant pressure of the entire pipeline system is achieved through the constant pressure water supply pipe 11 (connected with a constant pressure water supply device).

[0025] The insulated water tank 1 stores waste heat from the RTO exhaust gas treatment device 2 and the air compressor waste heat recovery device, and at the same time meets the heat demand of the workshop air-conditioning unit and the thermal oil oven waste heat utilization unit, and is a bridge and link connecting the other four units.

[0026] The connection between the hot water storage tank 1 and the water pipes requires that the cold water pipe is connected to the lower part of the water tank, and the hot water pipe is connected to the upper part of the water tank, and the cold and hot water flow in an orderly manner to avoid mixing of the upper hot water and the lower cold water in the water tank.

[0027] 2) For the RTO combustion waste heat recovery unit composed of the heat storage tank 1 and the RTO waste gas treatment device 2: the organic waste gas containing a large amount of VOCs from the printing workshop enters the RTO waste gas treatment device 2 through the exhaust duct of the printing workshop, and is discharged through the exhaust duct after catalytic combustion. At this time, the flue gas temperature can reach 200~250℃. The subsequent pipeline is divided into two routes, one is the waste heat recovery pipeline where the second branch pipe is located, and the other is the direct discharge pipeline into the chimney 21 where the first branch pipe is located. When it is necessary to recover the waste heat of the RTO flue gas, the first air valve 22 is closed, the second air valve 23 is opened, and the high-temperature flue gas heats the cold water from the heat storage tank 1 through the flue gas-water heat exchanger 24. After the flue gas temperature is reduced, it enters the chimney 21 through the second branch pipe and is discharged at high altitude.

[0028] The cold water from the lower side of the hot water storage tank 1 is pressurized by the flue gas waste heat recovery circulation pump 25, enters the first circulation water outlet pipe 16, is heated by the high-temperature flue gas through the flue gas-water heat exchanger 24, enters the first circulation water return pipe 12, and returns to the upper side of the hot water storage tank 1 to store heat.

[0029] In summer, when the flue gas waste heat from RTO catalytic combustion is excessive and the temperature of the heat storage tank 1 is too high (over 70°C), the second air valve 23 is closed and the first air valve 22 is opened to stop the storage and recovery of flue gas waste heat. The high-temperature flue gas enters the first branch pipe and is directly discharged into the air through the chimney 21.

[0030] 3) For air compressor waste heat recovery device:

[0031] The lubricating oil flows and circulates in the high-temperature oil supply pipe 34 and the low-temperature oil return pipe 35 of the air compressor 31. The air compressor 31 generates a large amount of heat in the process of producing compressed air, which causes the compressor lubricating oil to heat up significantly. When the waste heat is recovered, the high-temperature oil supply pipe 34 connected to the air compressor 31 enters the air compressor waste heat recovery heat exchanger 32, is cooled in the air compressor waste heat recovery heat exchanger 32, and returns to the air compressor 31 through the low-temperature oil return pipe 35.

[0032] The cold water from the lower side of the hot water storage tank 1 is pressurized by the air compressor waste heat recovery circulation pump 39, enters the second circulation outlet pipe 17, is heated by the high-temperature lubricating oil in the air compressor waste heat recovery heat exchanger 32, enters the second circulation return pipe 13, and returns to the upper side of the hot water storage tank 1 to store heat.

[0033] In summer, when the air compressor 31 has excess waste heat and the temperature of the water storage tank 1 is too high (over 70°C), the air compressor waste heat recovery circulation pump 39 stops running, and the storage and recovery of the air compressor waste heat is stopped. The air compressor 31 starts the cooling water system to dissipate heat. The cooling water (32°C) from the cooling tower 33 enters the air compressor through the cooling water supply pipe 36 to cool the high-temperature lubricating oil, and then is pressurized by the cooling water circulation pump 38 and transported by the cooling water return pipe 37 and returned to the cooling tower 33.

[0034] 4) For the waste heat utilization unit of thermal oil oven:

[0035] The oil supply temperature required by the thermal oil oven 41 is 95°C, while the water temperature in the hot water storage tank 1 is about 60°C. The high-temperature heat pump unit 43 is used to increase the temperature to meet the use requirements. The evaporator side of the high-temperature heat pump unit 43 is connected to a water circulation system, and the condenser side is connected to a thermal oil circulation system.

[0036] The 60°C hot water from the upper side of the hot water storage tank 1 is pressurized by the hot water circulation pump 49 of the thermal oil drying oven, enters the evaporator of the high-temperature heat pump unit 43 through the third circulation outlet pipe 14 for heat exchange, and the temperature is reduced to about 55°C. It returns to the lower side of the hot water storage tank 1 through the third circulation return pipe 18.

[0037] The heat transfer oil (about 90°C) after heat exchange and cooling in the heat transfer oil oven 41 is transported through the heat transfer oil return pipe 45, and pressurized by the heat transfer oil circulation pump 46, and enters the condenser side of the high-temperature heat pump unit 43. After being heated (about 95°C), it enters the heat transfer oil oven 41 through the heat transfer oil supply pipe 44 and the third butterfly valve 47 to heat the air and quickly dry the printing ink. The third butterfly valve 47 is used to adjust the flow rate of the heat transfer oil entering the heat transfer oil oven 41, and then adjust the air temperature in the heat transfer oil oven 41.

[0038] The inlet of the heat transfer oil circulation pump 46 and the heat transfer oil return pipe 45 are connected to a heat transfer oil constant pressure expansion pipe 48, and a heat transfer oil high-level constant pressure expansion tank 42 is provided at the upper part of the system for constant pressure of the heat transfer oil system.

[0039] 5) For the workshop air-conditioning unit: the hot water (about 60°C) from the upper side of the hot water storage tank 1 is pressurized by the hot water circulation pump 54 for air conditioning, transported through the fourth circulation outlet pipe 15, and enters the air-conditioning unit 51 through the fourth butterfly valve 55 for heating the air-conditioning unit. After the hot water exchanges heat with the air, the temperature drops to about 55°C and returns to the hot water storage tank 1 through the fourth circulation return pipe 19.

[0040] In summer, fresh air from the outside enters the air conditioning unit 51 through the fresh air valve 52, and is mixed with the workshop return air that enters the air conditioning unit through the return air valve 53. It is filtered by the primary and secondary filtration of the air conditioning unit 51, cooled and dehumidified by the surface cooling section until the humidity reaches the control requirement, and then is reheated by hot water in the heating section until the temperature reaches the control requirement, and then is pressurized by the blower and supplied to the room.

[0041] In winter, fresh air from the outside enters the air conditioning unit 51 through the fresh air valve 52, and after mixing with the workshop return air entering the air conditioning unit 51 through the return air valve 53, it is filtered by the primary and secondary filtration of the air conditioning unit 51, heated by hot water in the heating section, humidified in the humidification section, and after the supply air temperature and humidity meet the control requirements, it is pressurized by the fan section and sent into the room.

[0042] The fourth butterfly valve 55 is used to adjust the heating amount of the air conditioning unit 51 by adjusting the hot water flow rate according to the demand of the air conditioning unit, thereby adjusting the supply air temperature.

[0043] The utility model has the following two operating modes:

[0044] 1) Summer operation mode:

[0045] The recovered waste heat from the RTO waste gas treatment device 2 and the air compressor waste heat recovery device is stored in the hot water storage tank 1 and can be used for heating the oil-conducting hot oven 41 and reheating the air after dehumidification in the summer of the air conditioning unit 51. When the recovered waste heat is excessive and cannot be fully utilized (manifested by the temperature of the hot water storage tank being too high, exceeding 70°C):

[0046] For the RTO waste gas treatment device 2: the second air valve 23 is closed, the first air valve 22 is opened, the storage and recovery of flue gas waste heat are stopped, and the high-temperature flue gas enters the first branch pipe direct discharge pipeline and is directly discharged into the air through the chimney 21.

[0047] For the air compressor waste heat recovery device: the air compressor waste heat recovery circulation pump 39 stops running, and the storage and recovery of waste heat from the air compressor stops. The air compressor starts the cooling water system to dissipate heat. The cooling water (32°C) from the cooling tower 33 enters the air compressor through the cooling water supply pipe 36 to cool the high-temperature lubricating oil, and then returns to the cooling tower 33 through the pressurization of the cooling water circulation pump 38 and the transportation of the cooling water return pipe 37.

[0048] 2) Winter operation mode:

[0049] The recovered waste heat from the RTO waste gas treatment device 2 and the air compressor waste heat recovery device is stored in the hot water storage tank 1 and is completely used for heating the oil-conducting hot oven 41 and the air conditioning unit 51.

[0050] It should be noted that, in the description of the present invention, terms indicating orientation or positional relationships, such as "front", "rear", "left", "right", "vertical", "horizontal", "inside", "outside", etc., are based on the orientation or positional relationships shown in the drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

Claims

1. A waste heat recovery system for a printing workshop, characterized by: include A hot water storage tank, the hot water storage tank is provided with a water supply pipe, and is also provided with a first circulation return pipe, a second circulation return pipe, a third circulation outlet pipe, a fourth circulation outlet pipe located at the upper part, and a first circulation outlet pipe, a second circulation outlet pipe, a third circulation return pipe, and a fourth circulation return pipe located at the lower part; An RTO waste gas treatment device, wherein the inlet end of the RTO waste gas treatment device is connected to the workshop exhaust duct, and the outlet end is connected to the chimney through a smoke exhaust duct, and a first branch pipe and a second branch pipe are arranged in parallel on the smoke exhaust duct, the first branch pipe is provided with a first air valve, and the second branch pipe is provided with a second air valve and a flue gas-water heat exchanger, and the flue gas-water heat exchanger is connected to the first circulating water outlet pipe and the first circulating water return pipe; An air compressor waste heat recovery device, the air compressor waste heat recovery device comprises an air compressor, an air compressor waste heat recovery heat exchanger and a cooling tower, a high-temperature oil supply pipe and a low-temperature oil return pipe are arranged between the air compressor and the air compressor waste heat recovery heat exchanger, a cooling water supply pipe and a cooling water return pipe are arranged between the air compressor waste heat recovery heat exchanger and the cooling tower, and the air compressor waste heat recovery heat exchanger and the hot water storage tank are connected through the second circulation outlet pipe and the second circulation return pipe; A heat transfer oil oven waste heat utilization unit, the heat transfer oil oven waste heat utilization unit comprises a heat transfer oil oven, a heat transfer oil high-position constant pressure expansion tank, and a high-temperature heat pump unit. A heat transfer oil supply pipe and a heat transfer oil return pipe are provided between the heat transfer oil oven and the condenser of the high-temperature heat pump unit. The heat transfer oil high-position constant pressure expansion tank is connected to the heat transfer oil supply pipe / the heat transfer oil return pipe through the heat transfer oil constant pressure expansion pipe. The evaporator and the heat storage tank of the high-temperature heat pump unit are connected to the third circulation water outlet pipe and the third circulation water return pipe; The air conditioning unit is connected to the hot water storage tank via the fourth circulating water outlet pipe and the fourth circulating water return pipe.

2. The printing workshop waste heat recovery system according to claim 1 is characterized in that: The first circulation water outlet pipe or the first circulation water return pipe is provided with a flue gas waste heat recovery circulation pump, the second circulation water outlet pipe or the second circulation water return pipe is provided with an air compressor waste heat recovery circulation pump, the cooling water supply pipe or the cooling water return pipe is provided with a cooling water circulation pump, the third circulation water outlet pipe or the third circulation water return pipe is provided with a hot water circulation pump for a thermal oil oven, the thermal oil supply pipe or the thermal oil return pipe is provided with a thermal oil circulation pump, and the fourth circulation water outlet pipe or the fourth circulation water return pipe is provided with a hot water circulation pump for an air conditioner.

3. The printing workshop waste heat recovery system according to claim 1 is characterized in that: A third butterfly valve is arranged on the heat transfer oil supply pipe or the heat transfer oil return pipe.

4. The printing workshop waste heat recovery system according to claim 1 is characterized in that: The air conditioning unit is provided with a fresh air valve and a return air valve, and the fourth circulation water outlet pipe or the fourth circulation water return pipe is provided with a fourth butterfly valve.

5. The printing workshop waste heat recovery system according to claim 1 is characterized in that: The air compressor waste heat recovery device, the thermal oil drying oven and the air conditioning unit are arranged in parallel in two or more sets.

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