Heat supply, cold supply and air compression equipment coupling control system and control method thereof

Abstract

The invention discloses a heat supply, cold supply and air compression equipment coupling control system and a control method thereof. The heat supply, cold supply and air compression equipment coupling control system comprises a heat energy recoverer; the hot water return side of the heat user is sequentially connected with the low-temperature side of the heat energy recoverer and the heat storage device and returns to the hot water inlet side of the heat user; the air compressor is connected with the high-temperature side of the heat energy recoverer to form a circulation loop; a water inlet on the hot water side of the combined cooling and heating unit is connected with the hot water return side of the heat user; a water outlet on the hot water side is connected to the high-temperature side of the heat energy recoverer; the cold user is connected with the chilled water side of the combined cooling and heating unit to form a circulation loop; the cold user is connected with a water chilling unit in parallel. The problems that energy consumption of an existing enterprise lacks effective integration, waste heat and waste energy are greatly wasted, and the energy cost is high are solved.

Description

[Technical field]

[0001] The present invention belongs to the technical field of comprehensive utilization of cold and heat, and in particular relates to a coupling control system for heating, cooling and air compression equipment and a control method thereof. [Background technology]

[0002] In industries such as substrate glass production and automobile manufacturing, there is a demand for chilled water, hot water, and compressed air in the public auxiliary energy supply. Usually different energy sources are provided by different energy power equipment, cold is provided by compression chillers, heat is provided by boilers, and compressed air is provided by air compressors. Each energy system is isolated, and the energy connection between different systems is not considered. When the chiller is running, the heat discharged to the atmosphere through circulating cooling water can reach more than 1.15 times the cooling capacity; when the air compressor is running, more than 80% of the electrical energy is converted into thermal energy and discharged to the atmosphere through circulating cooling water; but when the boiler is running, it usually consumes high-grade energy such as natural gas or electricity to generate thermal energy. Therefore, due to the lack of intelligent comprehensive energy planning for the energy system and the lack of effective integration of the enterprise's energy use, a large amount of waste heat and energy is wasted, and the energy cost is high. [Summary of the invention]

[0003] The purpose of the present invention is to provide a heating, cooling and air compression equipment coupling control system and a control method thereof, so as to solve the problem that the existing enterprise energy consumption lacks effective integration, resulting in a large amount of waste heat and waste energy and high energy costs.

[0004] The present invention adopts the following technical solution: a heating, cooling and air compression equipment coupling control system, comprising:

[0005] a heat recovery device having a high temperature side and a low temperature side;

[0006] A heat user, which has a hot water return side and a hot water inlet side; the hot water return side is connected to the low temperature side of the heat energy recovery device and the heat storage device in sequence, and returns to the hot water inlet side of the heat user;

[0007] an air compressor connected to the high temperature side of the heat recovery device to form a circulation loop;

[0008] A combined cooling and heating unit, which has a chilled water side and a hot water side; the chilled water side of the combined cooling and heating unit corresponds to the evaporator, and the hot water side corresponds to the condenser; the water inlet of the hot water side is connected to the hot water return side of the heat user; the water outlet of the hot water side is connected to the high temperature side of the heat energy recovery device;

[0009] A cold user, which is connected to the chilled water side of the combined cooling and heating unit to form a circulation loop; the cold user is connected in parallel with a chiller;

[0010] The waste heat of the air compressor is collected in the heat recovery device, stored in the heat storage device, and then delivered to the heat user; the heat on the hot water side of the combined heat and cold supply unit is delivered to the heat recovery device to supplement the heat supply to the heat user;

[0011] The chilled water side of the combined cooling and heating unit is used to supply cooling to the cooling users; the chiller is used to supplement the cooling provided by the combined cooling and heating unit to the cooling users.

[0012] Furthermore, the heat user is connected in parallel with a hot water boiler.

[0013] Furthermore, the heat recovery device is connected in parallel with a cooling tower.

[0014] Furthermore, the condensing side of the chiller is connected to cooling tower three to form a circulation loop.

[0015] Furthermore, a cooling tower 2 is connected in parallel to the hot water side of the combined cooling and heating unit.

[0016] Furthermore, it also includes a control device and a display device.

[0017] The second technical solution adopted by the present invention is a control method of a heating, cooling and air compression equipment coupling control system. Based on a heating, cooling and air compression equipment coupling control system, the heating control method includes the following contents:

[0018] Obtaining real-time heat load or predicted heat load of heat users;

[0019] When the heat load is less than or equal to the heat recovered by the heat recovery device, the hot water return water of the heat user is only heated by the heat recovery device before being sent to the heat user;

[0020] When the heat supply of the heat recovery device is less than or equal to the heat load and less than or equal to the sum of the heat supply of the heat recovery device and the combined cooling and heating unit, the hot water return water of the heat user is heated by the combined cooling and heating unit and the heat recovery device in turn before being sent to the heat user;

[0021] When the heat load is ≥ the sum of the heat supply of the heat recovery device and the combined heat and cooling unit, the hot water return water of the heat user is divided into two paths, one path is heated by the combined heat and cooling unit and the heat recovery device in turn before going to the heat user, and the other path is heated by the hot water boiler before going to the heat user.

[0022] Furthermore, the cooling control method includes the following contents:

[0023] When the control device detects only the cooling load of cold users and no heating load of hot users, the chiller is turned on for cooling;

[0024] When the control device detects only the cooling load of cold users and the heating load of hot users, and the waste heat of the air compressor cannot meet all the heating loads, the combined cooling and heating unit is turned on to provide cooling and heating at the same time, and the shortfall of cooling load is provided by the chiller;

[0025] When the cooling load of the cold user is large, and the combined cooling and heating unit has a small cooling capacity due to the heat supply limitation, the chiller is not enough to meet all the heat supply, and the remaining cooling capacity is supplied by the combined cooling and heating unit. At this time, when the heat supply of the combined cooling and heating unit is greater than the demand of the heat user, it is dissipated through Cooling Tower 2. At this time, Cooling Tower 2 and the hot water recovery on the heat user side dissipate heat in parallel.

[0026] The beneficial effects of the present invention are as follows: the present invention uses a heat recovery device to recover the waste heat of the air compressor system, reducing the dissipation of the waste heat of the air compressor in the atmosphere. The waste heat of the chiller is recovered by a combined cooling and heating unit, reducing the dissipation of the waste heat of the refrigeration unit in the atmosphere. The waste heat recovery of the air compressor and the waste heat recovery of the chiller reduces the heat dissipation load of the cooling tower, reduces the operating time of the circulating cooling water system, reduces the power consumption of the circulating water pump and the cooling tower, and saves energy.

[0027] Compared with a single combined heat and cooling unit, the hot water temperature generated by the air compressor waste heat through the heat recovery device is higher, and the outlet water of the combined heat and cooling system can continue to be heated. When the water supply temperature of the heat user is constant, the outlet water temperature of the combined heat and cooling system can be reduced to improve the COP of the combined heat and cooling unit. Compared with the single air compressor waste heat recovery, the combined heat and cooling system preheats the hot water, and the temperature of the hot water entering the heat recovery device is relatively high, which reduces the heat exchange temperature difference on both sides of the heat recovery device and ensures the normal operation of the air compressor system. The use of waste heat recovery inside the kinetic energy system for heating reduces the heat output of the hot water boiler and reduces the heating cost of the plant; it enhances the coupling of the plant's energy system, reduces the installed scale of the hot water boiler, and can effectively reduce the initial investment and floor space of the system.

Brief Description of the Drawings

[0028] Figure 1 The present invention is a schematic diagram of the connection relationship of a heating, cooling and air compression equipment coupling control system.

[0029] Among them, 1. air compressor, 2. heat recovery device, 3. cooling tower one, 4. combined heat and cold supply unit, 5. cooling tower two, 6. heat storage device, 7. heat user, 8. hot water boiler, 9. cold user, 10. chiller, 11. cooling tower three, 12. control equipment, 13. display equipment. [Specific implementation method]

[0030] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] The present invention provides a coupling control system for heating, cooling and air compression equipment, such as Figure 1 As shown, it includes a heat recovery device 2, a heat user 7, a heat storage device 6, an air compressor 1, a combined cooling and heating unit 4, a cold user 9 and a chiller 10.

[0032] Among them, the heat recovery device 2 has a high temperature side and a low temperature side. The heat user 7 has a hot water return side and a hot water inlet side. The hot water return side of the heat user 7 is connected to the low temperature side of the heat recovery device 2 and the heat storage device 6 in turn, and returns to the hot water inlet side of the heat user 7. The air compressor 1 is connected to the high temperature side of the heat recovery device 2 to form a circulation loop. The heat storage device 6 can store the recovered waste heat, which plays a role in improving the stability of heat output, peak regulation and supply guarantee.

[0033] The combined cooling and heating unit 4 has a chilled water side and a hot water side. The chilled water side of the combined cooling and heating unit 4 corresponds to the evaporator, and the hot water side corresponds to the condenser. The water inlet of the hot water side of the combined cooling and heating unit 4 is connected to the hot water return side of the heat user 7, and the water outlet of the hot water side of the combined cooling and heating unit 4 is connected to the low temperature side of the heat energy recovery device 2. The cold user 9 is connected to the chilled water side of the combined cooling and heating unit 4 to form a circulation loop. The cold user 9 is connected in parallel with the chiller 10. The chilled water side of the chiller 10 corresponds to the evaporator, and the circulating cooling water side corresponds to the condenser.

[0034] Among them, the waste heat of the air compressor 1 is collected to the heat recovery device 2, stored in the heat storage device 6, and then delivered to the heat user 7; the heat on the hot water side of the combined cooling and heating unit 4 is used to be delivered to the heat recovery device 2 and then transferred to the heat user 7 through the heat storage device 6 to supplement the heat supply to the heat user 7. The chilled water side of the combined cooling and heating unit 4 is used to supply cold to the cold user 9; the chiller 10 is used to supplement the cold supply of the combined cooling and heating unit 4 to the cold user 9. That is, when the amount of chilled water generated by the combined cooling and heating unit 4 does not meet the demand, the chiller 10 will supplement it.

[0035] The required chilled water is produced in the evaporator of the combined cooling and heating unit 4 and supplied to the cold user 9, and the hot water produced by the condenser of the combined cooling and heating unit 4 reaches the air compressor heat recovery device 2 through the hot water pipeline for further heating and then is sent to the hot user 7. The hot water return water of the hot user 7 can first flow through the combined cooling and heating unit 4 for heating, and then flow through the heat recovery device 2 for further heating; or directly flow through the heat recovery device 2 for heating.

[0036] In some embodiments, the heat user 7 is connected in parallel with a hot water boiler 8. When the hot water produced by the heat user 7 does not meet the demand, the hot water boiler 8 is used to supplement it.

[0037] In some embodiments, the heat recovery device 2 is connected in parallel with a cooling tower 3. The waste heat generated by the air compressor 1 is used to generate hot water through the heat recovery device 2, or is discharged into the atmosphere through the cooling tower 3. When the air compressor 1 is operating normally, waste heat is generated, which needs to be taken away by circulating cooling water and then dissipated through the cooling tower. When the heat dissipation is abnormal, it will affect the operation of the air compressor 1. Since it cannot be guaranteed that the waste heat of the air compressor 1 can be completely recovered by the heat recovery device 2, it is necessary to connect a cooling tower 3 in parallel to ensure the normal operation of the air compressor 1.

[0038] In some embodiments, the condensing side of the chiller 10 is connected to a cooling tower 3 11 to form a circulation loop. When the chiller 10 is operating normally, waste heat is generated, which needs to be removed by circulating cooling water and then dissipated through the cooling tower 3 11. If the heat dissipation is abnormal, the operation of the chiller will be affected.

[0039] In some embodiments, a cooling tower 2 5 is connected in parallel to the hot water side of the combined cooling and heating unit 4. When the combined cooling and heating unit 4 only bears the cooling load and does not bear the heat load, the waste heat generated needs to be taken away by circulating cooling water, and then dissipated through the cooling tower 2 5, otherwise it cannot operate normally. If the chiller 4 can meet the maximum cooling load demand of the cold user 9, the combined cooling and heating unit 4 only bears the heat load and does not need the cooling tower 2 5, but this method requires a large capacity for the chiller 4, which does not conform to the principle of reducing the configuration capacity of the kinetic energy system and intensive land use, and is also inconsistent with the actual situation.

[0040] In some embodiments, a control device 12 and a display device 13 are also included. The control device can monitor the operating parameters of heat users, cold users, and air compressors; the control device can monitor and control the operating status of air compressors, heat recovery devices, cooling towers 1, combined heat and cold supply units, cooling towers 2, heat storage devices, hot water boilers, chillers, cooling towers, and auxiliary valves such as electric three-way regulating valves; the control device can select the most appropriate operating mode according to the real-time parameters of heat users, cold users, and air compressors or load forecasts based on historical data to guide the operation of other equipment and facilities; the control device can transmit the monitoring signal to the display device for display. The purpose of transmitting to the display device is to enable the operation and maintenance personnel to intuitively understand the implementation status of the equipment operation, record relevant operation data, and perform maintenance and other operations on the equipment without affecting the actual operation and regulation of the system.

[0041] The present invention provides a method for using a coupled control system for heating, cooling and air compression equipment, wherein the waste heat of air compression is discharged into the atmosphere through a heat recovery device 2 to generate hot water or through a cooling tower 3. The hot water return water of the heat user 7 first flows through a combined cooling and heating unit 4 for heating, and then flows through a heat recovery device 2 for further heating; or directly flows through a heat recovery device 2 for heating; the hot water generated after being heated by the heat recovery device 2 is supplied to the heat user 7 after passing through a heat storage device 6. When the load of the combined cooling and heating unit 4 is adjustable in real time, when the heating demand is met, the excess cold load is borne by the chiller 10. When the generated hot water does not meet the heat load demand, it is supplemented by a hot water boiler 8. Valves are provided at the intersection of each pipeline in the entire control system, and the opening and optimization scheduling of the combined cooling and heating unit 4, the chiller 10, the hot water boiler 8, each cooling tower and valve are all intelligently regulated by a control device 12.

[0042] The present invention also provides a control method for a coupled control system of heating, cooling and air compression equipment. Based on a coupled control system of heating, cooling and air compression equipment, the control method for heating includes the following contents:

[0043] Obtaining real-time heat load or predicted heat load of heat users;

[0044] When the heat load is less than or equal to the heat recovered by the heat recovery device 2, the hot water return water of the heat user 7 is only heated by the heat recovery device 2 before being sent to the heat user 7;

[0045] When the heat supply of the heat recovery device 2 is less than or equal to the heat load and less than or equal to the sum of the heat supply of the heat recovery device 2 and the combined cooling and heating unit 4, the hot water return water of the heat user 7 is heated by the combined cooling and heating unit 4 and the heat recovery device 2 in turn before being sent to the heat user 7;

[0046] When the heat load is ≥ the sum of the heat supply of the heat recovery device 2 and the combined heat and cooling unit 4, the hot water return water of the heat user 7 is divided into two paths, one path is heated by the combined heat and cooling unit 4 and the heat recovery device 2 in turn and then goes to the heat user 7, and the other path is heated by the hot water boiler 8 and then goes to the heat user 7.

[0047] In some embodiments, the cooling control method includes the following:

[0048] When the control device 12 detects only the cooling load of the cold user 9 and no heating load of the hot user 7, the chiller 10 is turned on to provide cooling;

[0049] When the control device 12 detects only the cooling load of the cold user 9 and the heating load of the hot user 7, and the waste heat of the air compressor 1 cannot meet all the heating loads, the combined cooling and heating unit 4 is turned on to provide cooling and heating at the same time, and the shortfall of cooling load is provided by the chiller 10;

[0050] When the cooling load of the cold user 9 is large, and the cooling capacity of the combined cooling and heating unit 4 is small due to the heat supply limit, the chiller 10 is insufficient to meet all the heat supply, and the remaining cooling capacity is supplied by the combined cooling and heating unit 4. At this time, when the heat supply of the combined cooling and heating unit 4 is greater than the demand of the heat user 7, it is dissipated through the cooling tower 2 5. At this time, the cooling tower 2 5 and the hot water recovery on the heat user side are connected in parallel to dissipate heat.

[0051] In addition, before controlling a coupling control system for heating, cooling and air compressor equipment, the heat user load, cooling user load and compressed air load can be monitored, or load fluctuations can be predicted based on historical data; determine the start-up status of the air compressor equipment. The cooling, heating and air compressor systems themselves have detection systems, and load prediction is not necessary before control. The control methods of all systems are dynamically adjusted during operation. The refrigeration system will install a temperature sensor on the supply and return water main pipe on the cold user side. The supply and return water temperatures are fixed during normal cooling. Changes in the supply and return water temperatures during operation indicate that the cooling load has fluctuated, and the refrigeration equipment is adjusted accordingly. Usually, the supply water temperature is kept consistent during the operation of the refrigeration system. When the return water temperature increases, it indicates that the cooling load has increased, and the cooling capacity of the refrigeration equipment needs to be increased; when the return water temperature decreases, it indicates that the cooling load has decreased, and the cooling capacity of the refrigeration equipment needs to be reduced.

[0052] The heating system is similar to the cooling system. A temperature sensor device will be installed on the main water supply and return pipe on the heat user side. During normal heating, the supply and return water temperatures are fixed. Changes in the supply and return water temperatures during operation indicate that the heat load has fluctuated, and the heating equipment is adjusted accordingly. Usually, the supply water temperature is kept consistent during the operation of the heating system. When the return water temperature increases, it means that the heat load has decreased, and the heating supply of the heating equipment needs to be reduced; when the return water temperature decreases, it means that the heat load has increased, and the heating supply of the heating equipment needs to be increased.

[0053] The air compression system will install a pressure sensor on the air supply main on the air compression user side. During normal air supply, the main pressure is a fixed value. Changes in the air supply pressure during operation indicate fluctuations in the air load, and the air supply of the air compressor is adjusted accordingly. When the main pressure increases, it means that the air load has decreased, and the air supply of the air compressor needs to be reduced; when the main pressure decreases, it means that the air load has increased, and the air supply of the air compressor needs to be increased. When the control device obtains the load of the refrigeration, heating and air compression systems, it will calculate the corresponding refrigeration waste heat, air compression waste heat and thermal load; then perform load analysis and distribute the load of the cooling and heating equipment; finally, the command is issued, and each device is operated to supply the cooling, heating and air compression needs of the factory.

[0054] The following are several control methods for effectively integrating heating and cooling in a coupled control system for heating, cooling and air compression equipment:

[0055] Embodiment 1: When the heat load is less than or equal to the heat supply of the heat recovery device 2, the refrigeration system operates independently;

[0056] The air compressor 1 is turned on, the heat recovery device 2 is turned on, the cooling tower 3 is turned on, the heat storage device 6 is turned on, and the hot water boiler 8 is turned off.

[0057] The hot water return water of heat user 7 is heated by heat recovery device 2, then passes through heat storage device 6, and finally sent to heat user 7. Heat recovery device 2 and cooling tower 3 operate in parallel, jointly bearing the heat dissipation of air compressor 1, and the heat dissipation distribution is adjusted by the valve in the pipeline.

[0058] Example 2: When the heat supply of the heat recovery device 2 ≤ heat load ≤ the sum of the heat supply of the heat recovery device 2 and the combined heat and cold generation unit 4:

[0059] The air compressor 1 is turned on, the heat recovery device 2 is turned on, the combined cooling and heating unit 4 is turned on, the heat storage device 6 is turned on, the chiller 10 is turned on, and the cooling tower three 11 is turned on. The cooling tower one 3 is turned off, the cooling tower two 5 is turned off, and the hot water boiler 8 is turned off.

[0060] The hot water return water of the heat user 7 is firstly passed to the combined heat and cold supply unit 4 for heating, and then further heated by the heat recovery device 2, and then passed through the heat storage device 6, and finally sent to the heat user 7. The combined heat and cold supply unit 4 and the chiller 10 are operated in parallel, and jointly bear the cooling load of the cold user 9, and the heat load distribution is adjusted by the valve in the pipeline.

[0061] Example 3: When the heat load is greater than the sum of the heat supply of the heat recovery device 2 and the combined cooling and heating unit 4:

[0062] The air compressor 1 is turned on, the heat recovery device 2 is turned on, the combined cooling and heating unit 4 is turned on, the heat storage device 6 is turned on, and the hot water boiler 8 is turned on. The cooling tower 1 3 is turned off, and the cooling tower 2 5 is turned off.

[0063] The hot water return water of the heat user 7 is partially passed to the combined heat and cold supply unit 4 for heating, then further heated by the heat recovery device 2, and then passed through the heat storage device 6, and finally sent to the heat user 7; part of it is heated by the hot water boiler 8 and finally sent to the heat user 7. The combined heat and cold supply unit 4 and the chiller 10 operate in parallel, jointly bearing the cooling load of the cold user 9, and the cooling load distribution is adjusted by the valve in the pipeline.

[0064] Embodiment 4: When there is a cooling load and the heating does not require refrigeration waste heat, the heating and air compression systems operate independently and have nothing to do with the refrigeration system;

[0065] If the cooling load is less than or equal to the cooling capacity of the refrigeration unit, the chiller 10 is turned on, the cooling tower 3 11 is turned on, the combined cooling and heating unit 4 is turned off, and the cooling tower 2 5 is turned off. At this time, all the chilled water return water of the cold user flows through the chiller 10, and the residual heat of the chiller 10 is lost through the cooling tower 3 11.

[0066] If the cooling load is greater than the cooling capacity of the refrigeration unit: the chiller 10 is turned on, the cooling tower 3 11 is turned on, the combined cooling and heating unit 4 is turned on, and the cooling tower 2 5 is turned on. At this time, part of the cold user's chilled water return water flows through the chiller 10, and the residual heat of the chiller 10 is lost through the cooling tower 3 11. Part of it flows through the combined cooling and heating unit 4, and the residual heat of the combined cooling and heating unit 4 is lost through the cooling tower 5.

[0067] Embodiment 5: When there is a cooling load and the heating requires refrigeration waste heat, but the combined cooling and heating units do not need to operate at full load, the heating and cooling systems are coupled to operate;

[0068] If the cooling load is less than or equal to the cooling capacity of the combined cooling and heating unit, the chiller 10 is turned off, the cooling tower 3 11 is turned off, the combined cooling and heating unit 4 is turned on, and the cooling tower 2 5 is turned off. At this time, all the chilled water return water of the cold user flows through the combined cooling and heating unit 4, and all the waste heat of the combined cooling and heating unit 4 is taken away by the hot water return water of the hot user 7;

[0069] If the cooling capacity of the combined cooling and heating unit at non-full load is less than the cooling load and less than the sum of the cooling capacity of the combined cooling and heating unit and the cooling capacity of the chiller at non-full load: the chiller 10 is turned on, the cooling tower 3 11 is turned on, the combined cooling and heating unit 4 is turned on, and the cooling tower 2 5 is turned off. At this time, part of the chilled water return water of the cold user flows through the combined cooling and heating unit 4, and all the waste heat of the combined cooling and heating unit 4 is taken away by the hot water return water of the hot user 7. Part of it flows through the chiller 10, and the waste heat of the chiller 10 is lost through the cooling tower 3 11;

[0070] If the cooling load is greater than the sum of the cooling capacity of the combined cooling and heating unit and the cooling capacity of the chiller when the load is not full: the chiller 10 is turned on, the cooling tower 3 11 is turned on, the combined cooling and heating unit 4 is turned on, and the cooling tower 2 5 is turned on. At this time, part of the return water of the cold user's chilled water flows through the combined cooling and heating unit 4, and part of the waste heat of the combined cooling and heating unit 4 is taken away by the hot water return water of the hot user 7, and part of it is lost by the cooling tower 5. Part of it flows through the chiller 10, and the waste heat of the chiller 10 is lost through the cooling tower 3 11.

[0071] Example 6: When there is a cooling load and the heating requires refrigeration waste heat, and the combined cooling and heating units are required to operate at full load, refrigeration waste heat is required, and the heating and cooling systems are coupled to operate;

[0072] If the cooling load is less than or equal to the cooling capacity of the combined cooling and heating unit, the chiller 10 is turned off, the cooling tower 3 11 is turned off, the combined cooling and heating unit 4 is turned on, and the cooling tower 2 5 is turned off. At this time, all the chilled water return water of the cold user flows through the combined cooling and heating unit 4, and all the waste heat of the combined cooling and heating unit 4 is taken away by the hot water return water of the hot user 7;

[0073] If the cooling load is greater than the cooling capacity of the combined cooling and heating unit: the chiller 10 is turned on, the cooling tower 3 11 is turned on, the combined cooling and heating unit 4 is turned on, and the cooling tower 2 5 is turned off. At this time, part of the cold user's chilled water return water flows through the combined cooling and heating unit 4, and all the residual heat of the combined cooling and heating unit 4 is taken away by the hot water return water of the hot user 7. Part of it flows through the chiller 10, and the residual heat of the chiller 10 is lost through the cooling tower 3 11.

[0074] In summary, the control logic of the coupling control system of heating, cooling and air compressor equipment of the present invention is: for heating, the waste heat of the air compressor is used first, then the waste heat of the chiller 10 is used, and finally the hot water boiler 8 is turned on for heating. For cooling, the chiller 10 is turned on first, and then the combined cooling and heating unit 4 is turned on. The cooling energy efficiency level of the chiller is higher than that of the combined cooling and heating unit, so the chiller is turned on first.

[0075] The hot water return water of the heat user 7 partially passes through the combined cooling and heating unit 4 side, and partially passes through the boiler side. The hot water return water flowing to the combined cooling and heating unit 4 side is first heated by the combined cooling and heating unit 4, and then continues to be heated by the heat energy recovery device 2, and then passes through the heat storage device 6, and finally merges with the hot water supply from the hot water boiler 8 and is sent to the heat user 7. The combined cooling and heating unit 4 and the chiller 10 operate in parallel, jointly bearing the cold load of the cold user, and the heat load distribution is adjusted by the valve in the pipeline. The hot water boiler 8 is a supplementary heating device, and its heat load distribution is adjusted by the valve in the pipeline.

[0076] Case: The energy required in the process of an industrial plant is provided by the plant's kinetic energy system, which operates 24 hours a day, 365 days a year. The kinetic energy system covers a variety of energy sources such as process water, electricity, natural gas, chilled water, hot water, compressed air, etc. The annual primary energy cost is over 100 million yuan, which is an important part of the production cost of the plant's products. The plant's chilled water, hot water, and compressed air loads are as follows:

[0077] Hot water load:

[0078] The heating system is equipped with two 5.6MW gas-fired vacuum hot water boilers, with a supply and return water temperature of 50℃ / 45℃ and a boiler efficiency of 93.5%.

[0079]

[0080] Cooling load:

[0081] The refrigeration system is equipped with 5 4220KW (1200RT) centrifugal chillers with a supply and return water temperature of 7 / 12℃. Two units are used and three units are in reserve in winter, and three units are used and two units are in reserve in summer, with a cooling power of ≥8440kW.

[0082] Compressed air load:

[0083] The compressed air system is equipped with 5 centrifugal air compressors with a rated power of 900kW and an air output of 150Nm 3 / min, rated working pressure 0.8MPa, 2 air compressors are in daily operation.

[0084] Price boundary: Natural gas price 4.0 yuan / Nm 3 , electricity price is 0.55 yuan / kWh.

[0085] Based on the above information, consider using a heating, cooling and air compression equipment coupling control system of the present invention to transform and optimize the plant kinetic energy system. Satisfy the condition in Example 2 when the heating capacity of the heat recovery device 2 ≤ heat load ≤ the sum of the heating capacity of the heat recovery device 2 and the combined heat and cold supply unit 4. According to the load matching analysis, the optimization plan intends to completely replace the boiler room and supply hot water to the process. The waste heat of the air compressor is fully recovered, and then the heating capacity of the combined heat and cold supply unit is adjusted according to the fluctuation of the heat load for supplementary heating. The valves of each device in the system are dispatched by the control device.

[0086] The brief calculation process is as follows:

[0087] The heat power recovered by the heat recovery device of the air compressor waste heat is:

[0088] P1=2*900*80%*70%=1080kW

[0089] Heating power of the combined cooling and heating unit:

[0090] P2=1.2*4000-1080=3720kW

[0091] Therefore, the total heating power of the combined cooling and heating units to be configured is not less than 3720kW. Operating conditions: Chilled water supply and return water temperature 7 / 12℃, hot water supply and return water temperature 50℃ / 45℃. The COP of the combined cooling and heating system operation process is 4.2.

[0092] The annual boiler room heat supply is converted into natural gas, and the calorific value is 8200kcal / Nm 3 Perform calculations.

[0093] Q=2371*3.6*10 5 / (8200*4.186) / 93.5%=2.66 million Nm 3

[0094] The original annual heating cost is the natural gas cost:

[0095] E1=266*10 4 *4=10.64 million yuan,

[0096] The cost of the heating system after the transformation is the electricity consumption cost, which is mainly the electricity consumption of the combined heating and cooling units and the newly added water pumps. The COP of the combined heating and cooling system of this project is 4.2, the total power of the water pump is 220kW, and it runs at a fixed frequency for 24 hours.

[0097] Annual air compression waste heat heating:

[0098] G1=1080*365*24 / 10000=9.46 million kWh,

[0099] Heating capacity of combined cooling and heating system:

[0100] G2=2371-946=14.25 million kWh,

[0101] The annual electricity consumption cost of the combined cooling and heating system is:

[0102] F1=1425 / 4.2*0.55=1.87 million yuan,

[0103] The annual electricity consumption of the water pump is:

[0104] F2=220*365*24*0.55=1.06 million yuan,

[0105] Annual heating cost savings:

[0106] R=1064-187-106=7.71 million yuan.

[0107] After calculation, under the project conditions of Example 2, this case can reduce the annual heating cost of the enterprise by 7.71 million yuan and reduce carbon emissions by about 2,500 tons per year. When the cooling benefits brought by this system and the electricity saving benefits of the refrigeration and air-compressed circulating cooling system are considered at the same time, the energy-saving benefits will be more objective. When it is a new project, the installed capacity of the chiller, boiler and circulating cooling water system can be greatly reduced, saving land and reducing the initial investment of the kinetic energy system.

[0108] The present invention adopts the concept of intelligent comprehensive utilization, comprehensively considers the recovery of waste heat from the public auxiliary system of the plant area, realizes the step-by-step utilization of energy, reduces the heating cost, reduces the power consumption of the air compressor and cooling water system of the refrigeration system, and reduces the thermal pollution of the plant area. It is an effective way to achieve energy conservation and cost reduction in the plant area. When the project is newly built, the installed capacity of the boiler system can be greatly reduced, the site land can be saved, and the initial investment scale can be reduced.

[0109] The present invention uses a heat recovery device 2 to recover the waste heat of the air compressor system, reducing the dissipation of the waste heat of the air compressor in the atmosphere. The combined cooling and heating unit 4 is used to recover the waste heat of the chiller 10, reducing the dissipation of the waste heat of the refrigeration unit in the atmosphere. The waste heat recovery of the air compressor and the waste heat recovery of the chiller reduce the heat dissipation load of the cooling tower, reduce the operating time of the circulating cooling water system, reduce the power consumption of the circulating water pump and the cooling tower, and save energy.

[0110] Compared with a single combined heat and cooling unit, the hot water temperature generated by the air compressor waste heat through the heat recovery device is higher, and the outlet water of the combined heat and cooling system can continue to be heated. When the water supply temperature of the heat user is constant, the outlet water temperature of the combined heat and cooling system can be reduced to improve the COP of the combined heat and cooling unit. Compared with the single air compressor waste heat recovery, the combined heat and cooling system preheats the hot water, and the temperature of the hot water entering the heat recovery device is relatively high, which reduces the heat exchange temperature difference on both sides of the heat recovery device and ensures the normal operation of the air compressor system. The use of waste heat recovery inside the kinetic energy system for heating reduces the heat output of the hot water boiler and reduces the heating cost of the plant; it enhances the coupling of the plant's energy system, reduces the installed scale of the hot water boiler, and can effectively reduce the initial investment and floor space of the system.

Claims

1. A coupling control system for heating, cooling and air compression equipment, characterized in that: include: A heat recovery device (2) having a high temperature side and a low temperature side; A heat user (7) having a hot water return side and a hot water inlet side; The hot water return side is connected to the low temperature side of the heat energy recovery device (2) and the heat storage device (6) in sequence, and returns to the hot water inlet side of the heat user (7); An air compressor (1) connected to the high temperature side of the heat energy recovery device (2) to form a circulation loop; A combined cooling and heating unit (4) having a chilled water side and a hot water side; the chilled water side of the combined cooling and heating unit (4) corresponds to the evaporator, and the hot water side corresponds to the condenser; the water inlet of the hot water side is connected to the hot water return side of the heat user (7); and the water outlet of the hot water side is connected to the high temperature side of the heat recovery device (2); A cold user (9) connected to the chilled water side of the combined cooling and heating unit (4) to form a circulation loop; the cold user (9) is connected in parallel to a chiller (10); The waste heat of the air compressor (1) is collected in the heat recovery device (2), stored in the heat storage device (6), and then delivered to the heat user (7); the heat on the hot water side of the combined heat and cold supply unit (4) is delivered to the heat recovery device (2) to supplement the heat supply to the heat user (7); The chilled water side of the combined cooling and heating unit (4) is used to supply cooling to the cooling user (9); the chiller (10) is used to supplement the cooling provided by the combined cooling and heating unit (4) to the cooling user (9).

2. A heating, cooling and air compression equipment coupling control system as claimed in claim 1, characterized in that: The heat user (7) is connected in parallel with a hot water boiler (8).

3. A heating, cooling and air compression equipment coupling control system as claimed in claim 1 or 2, characterized in that: The heat energy recovery device (2) is connected in parallel with a cooling tower (3).

4. A heating, cooling and air compression equipment coupling control system as claimed in claim 1 or 2, characterized in that: The condensation side of the chiller (10) is connected to a cooling tower three (11) to form a circulation loop.

5. A heating, cooling and air compression equipment coupling control system as claimed in claim 1 or 2, characterized in that: A second cooling tower (5) is connected in parallel to the hot water side of the combined cooling and heating unit (4).

6. A heating, cooling and air compression equipment coupling control system as claimed in claim 1 or 2, characterized in that: It also includes a control device (12) and a display device (13).

7. A control method for a coupled control system of heating, cooling and air compression equipment, characterized in that: Based on a heating, cooling and air compression equipment coupling control system according to any one of claims 1 to 6, a heating control method comprises the following contents: Obtaining real-time heat load or predicted heat load of heat users; When the heat load is less than or equal to the amount of heat recovered by the heat recovery device (2), the hot water return from the heat user (7) is only heated by the heat recovery device (2) before being sent to the heat user (7); When the heat supply of the heat recovery device (2) is less than or equal to the heat load and less than or equal to the sum of the heat supply of the heat recovery device (2) and the combined cooling and heating unit (4), the hot water return water of the heat user (7) is heated by the combined cooling and heating unit (4) and the heat recovery device (2) in sequence before being sent to the heat user (7); When the heat load is greater than or equal to the sum of the heat supply of the heat recovery device (2) and the combined cooling and heating unit (4), the hot water return water of the heat user (7) is divided into two paths, one path is heated by the combined cooling and heating unit (4) and the heat recovery device (2) in sequence before being sent to the heat user (7), and the other path is heated by the hot water boiler (8) before being sent to the heat user (7).

8. The control method according to claim 7, characterized in that: The control methods of cooling include the following: When the control device (12) detects only the cooling load of the cooling user (9) and no heating load of the heating user (7), the chiller (10) is turned on to provide cooling; When the control device (12) detects only the cooling load of the cold user (9) and the heating load of the hot user (7), and the waste heat of the air compressor (1) cannot meet all the heating loads, the combined cooling and heating unit (4) is turned on to provide cooling and heating at the same time, and the shortfall of cooling load is provided by the chiller (10); When the cooling load of the cold user (9) is large, and the cooling capacity of the combined cooling and heating unit (4) is small due to the heat supply limitation, the chiller (10) is insufficient to meet the total heat supply, and the remaining cooling capacity is supplied by the combined cooling and heating unit (4). When the heat supply of the combined cooling and heating unit (4) is greater than the demand of the heat user (7), the heat is dissipated through the cooling tower 2 (5). At this time, the cooling tower 2 (5) and the hot water recovery on the heat user side are connected in parallel to dissipate heat.

Images