Waste heat recovery system and method

Abstract

The invention provides a waste heat recovery system and method. The system comprises a heat exchange device, a heat pump device, an energy storage device and a water supplementing device. A first air inlet and a first air outlet are formed in the first end of the heat exchange device; to-be-recycled waste heat gas enters the heat exchange device from a first gas inlet in the first end of the heat exchange device, and is discharged from a first gas outlet after internal circulation of the heat exchange device; the second end of the heat exchange device is connected with the heat pump device; the heat pump device comprises a low-temperature heat pump and a high-temperature heat pump which are connected in series, the first end of the low-temperature heat pump is connected with the second end of the heat exchange device, the second end of the low-temperature heat pump is connected with the first end of the high-temperature heat pump, and the second end of the high-temperature heat pump is connected with the energy storage device. The water supplementing device is connected with the heat pump device and the energy storage device and supplements water into the heat pump device and the heat exchange device. According to the system, the gas waste heat is recovered and utilized, the energy storage water is heated to be used in the subsequent steps, the waste heat utilization maximization is achieved, and the energy-saving effect is remarkable.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of waste heat recovery and utilization, and in particular to a waste heat recovery system and method. Background Art

[0002] With the intensification of the global energy crisis and the improvement of environmental protection awareness, energy conservation and emission reduction have become important development goals for all countries. In the fields of industrial production and building heating and cooling, efficient use of energy is particularly important.

[0003] The existing refrigeration system runs all year round, generating a large amount of low-grade heat, which is discharged through evaporative cooling, while some process operations (such as packaging and brewing) require a large amount of hot water. Therefore, it is necessary to use heat pump technology to increase the heat of the recovered gas and use it for heating the energy storage water, which can reduce steam consumption on the one hand and reduce electricity and water consumption of evaporative cooling on the other hand. In the prior art, traditional heat pump systems often have energy loss problems during energy conversion and utilization, resulting in low energy efficiency of the overall system. Therefore, how to efficiently recover waste heat to form a closed-loop, efficient energy utilization system is still a technical problem that needs to be solved urgently. Summary of the invention

[0004] The embodiments of the present invention provide a waste heat recovery system and method to solve the problem that there is no efficient waste heat recovery system in the prior art.

[0005] In order to solve the above-mentioned technical problems, the present invention is achieved as follows:

[0006] In a first aspect, an embodiment of the present invention provides a waste heat recovery system, comprising:

[0007] Heat exchange devices, heat pump devices, energy storage devices and water replenishment devices;

[0008] The first end of the heat exchange device is provided with a first air inlet and a first air outlet; the waste heat gas to be recovered enters the heat exchange device from the first air inlet of the first end of the heat exchange device, and is discharged from the first air outlet of the first end of the heat exchange device after circulating inside the heat exchange device; the second end of the heat exchange device is connected to the heat pump device;

[0009] The heat pump device comprises: a low-temperature heat pump and a high-temperature heat pump, wherein the low-temperature heat pump and the high-temperature heat pump are connected in series, a first end of the low-temperature heat pump is connected to a second end of the heat exchange device, a second end of the low-temperature heat pump is connected to a first end of the high-temperature heat pump, and a second end of the high-temperature heat pump is connected to the energy storage device;

[0010] The water replenishing device is connected to the heat pump device and the energy storage device respectively to replenish water into the heat pump device and the heat exchange device.

[0011] Optionally, the heat exchange device includes a heat exchanger, a first pipe and a second pipe; the first end of the first pipe is connected to the air inlet of the waste heat gas to be recovered, and the second end of the first pipe is connected to the heat exchanger; the first end of the second pipe is connected to the exhaust port of the waste heat gas to be recovered, and the second end of the second pipe is connected to the heat exchanger; the waste heat gas to be recovered enters the heat exchanger through the first pipe, and the heat exchanger performs heat exchange on the waste heat gas to be recovered and then discharges the waste heat gas through the second pipe;

[0012] The second end of the heat exchanger is provided with a first water outlet and a first water inlet, and the first water outlet and the first water inlet are connected to the heat pump device.

[0013] Optionally, the heat exchanger is a plate heat exchanger.

[0014] Optionally, the heat pump device further includes: a third pipeline, a fourth pipeline, a fifth pipeline, a sixth pipeline, a first water pump group and a second water pump group;

[0015] The first end of the third pipeline is connected to the first water outlet of the heat exchange device, and the second end of the third pipeline is connected to the first end of the low-temperature heat pump; the first end of the fourth pipeline is connected to the first water inlet of the heat exchange device, and the second end of the fourth pipeline is connected to the first end of the low-temperature heat pump;

[0016] The first end of the fifth pipeline is connected to the second end of the low-temperature heat pump, and the second end of the fifth pipeline is connected to the first end of the high-temperature heat pump; the first end of the sixth pipeline is connected to the second end of the low-temperature heat pump, and the second end of the sixth pipeline is connected to the first end of the high-temperature heat pump;

[0017] The first water pump group is arranged on the fourth pipeline; the second water pump group is arranged on the fifth pipeline.

[0018] Optionally, the low-temperature heat pump includes a first evaporator and a first condenser;

[0019] The first end of the first evaporator is provided with a second water inlet and a second water outlet, the second water inlet is connected to the heat exchange device through the third pipe; the second water outlet is connected to the heat exchange device through the fourth pipe; the second end of the first evaporator is connected to the first end of the first condenser;

[0020] The second end of the first condenser is provided with a third water outlet and a third water inlet; the third water outlet is connected to the high-temperature heat pump through the fifth pipe; the third water inlet is connected to the high-temperature heat pump through the sixth pipe.

[0021] Optionally, the high temperature heat pump includes a second evaporator and a second condenser;

[0022] The first end of the second evaporator is provided with a fourth water inlet and a fourth water outlet, the fourth water inlet is connected to the low-temperature heat pump through the fifth pipe; the fourth water outlet is connected to the low-temperature heat pump through the sixth pipe; the second end of the second evaporator is connected to the first end of the second condenser;

[0023] The second end of the second condenser is provided with a fifth water outlet and a fifth water inlet; the fifth water outlet and the fifth water inlet are connected to the energy storage device.

[0024] Optionally, the energy storage device includes: a seventh pipeline, an eighth pipeline, a third water pump group and an energy storage tank;

[0025] The first end of the seventh pipeline is connected to the fifth water outlet of the high-temperature heat pump, and the second end of the seventh pipeline is connected to the first end of the energy storage water tank;

[0026] The first end of the eighth pipeline is connected to the fifth water inlet of the high-temperature heat pump, and the second end of the eighth pipeline is connected to the second end of the energy storage water tank; wherein the first end of the energy storage water tank is located higher than the second end;

[0027] The third water pump group is arranged on the eighth pipeline.

[0028] Optionally, the energy storage device further comprises: a ninth pipeline, a pneumatic butterfly valve and a temperature transmitter;

[0029] The ninth pipeline is arranged between the seventh pipeline and the eighth pipeline; a pneumatic butterfly valve is arranged on the ninth pipeline;

[0030] The temperature transmitter is arranged on one end of the seventh pipeline close to the energy storage water tank.

[0031] Optionally, the first water pump group and the second water pump group are provided with three groups of water pumps, two of which are in-use water pumps, and one of which is a standby water pump; the third water pump group is provided with two groups of water pumps, one of which is in-use water pumps, and the other is a standby water pump.

[0032] Optionally, the water replenishing device includes: a tenth pipeline, an eleventh pipeline and an expansion water tank;

[0033] The first end of the tenth pipeline is connected to the expansion water tank, and the second end of the tenth pipeline is connected to the fourth pipeline;

[0034] The first end of the eleventh pipe is connected to the expansion water tank, and the second end of the eleventh pipe is connected to the fifth pipe.

[0035] In a second aspect, an embodiment of the present invention provides a waste heat recovery method, using the waste heat recovery system as described in any one of the first aspects, the method comprising:

[0036] The waste heat gas to be recovered is input into the heat exchange device from the first air inlet, the heat exchange device performs heat exchange on the waste heat gas to be recovered, the heat exchange water in the heat exchange device after heat exchange enters the heat pump device from the first water outlet, and the waste heat gas to be recovered after heat exchange is discharged from the first air outlet;

[0037] The hot water is input into the low-temperature heat pump in the heat pump device for a first heat exchange to obtain low-temperature water; and the low-temperature water is then input into the high-temperature heat pump for a second heat exchange to obtain high-temperature water;

[0038] Inputting the high-temperature water into the energy storage water tank for storage, and inputting the energy storage water in the energy storage device that does not meet the preset temperature requirement into the high-temperature heat pump for circulation and reheating;

[0039] A water replenishing device is used to replenish water to the heat exchange device and the heat pump device.

[0040] In the present invention, a heat exchange device, a heat pump device, an energy storage device and a water replenishing device are provided; the first end of the heat exchange device is provided with a first air inlet and a first air outlet; the waste heat gas to be recovered enters the heat exchange device from the first air inlet of the first end of the heat exchange device, and is discharged from the first air outlet after circulating inside the heat exchange device; the second end of the heat exchange device is connected to the heat pump device; the heat pump device includes: a low-temperature heat pump and a high-temperature heat pump, the low-temperature heat pump and the high-temperature heat pump are connected in series, the first end of the low-temperature heat pump is connected to the second end of the heat exchange device, the second end of the low-temperature heat pump is connected to the first end of the high-temperature heat pump, and the second end of the high-temperature heat pump is connected to the energy storage device; the water replenishing device is connected to the heat pump device and the energy storage device respectively, and water is replenished to the heat pump device and the heat exchange device. The waste heat of the gas is recovered and utilized, and the energy storage water is heated for use in subsequent steps, so as to maximize the utilization of waste heat, achieve significant energy-saving effects, and solve the problem of the existing lack of efficient waste heat recovery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0042] Figure 1 is a structural schematic diagram of a waste heat recovery device provided by an embodiment of the present invention;

[0043] Figure 2It is a flow chart of a waste heat recovery method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0045] Please refer to Figure 1 , an embodiment of the present invention provides a waste heat recovery system, comprising:

[0046] Heat exchange device 1, heat pump device 2, energy storage device 3 and water replenishment device 4;

[0047] The first end of the heat exchange device 1 is provided with a first air inlet 11 and a first air outlet 12; the waste heat gas to be recovered enters the heat exchange device 1 from the first air inlet 11 at the first end of the heat exchange device 1, and is discharged from the first air outlet 12 at the first end of the heat exchange device 1 after circulating inside the heat exchange device 1; the second end of the heat exchange device 1 is connected to the heat pump device 2;

[0048] In the embodiment of the present invention, the waste heat gas to be recovered includes but is not limited to ammonia generated in the refrigeration workshop of the brewery, and waste heat to be recovered generated in other workshops such as dairy factories, beverage factories, food factories, bamboo product factories, and lithium battery industries.

[0049] In the embodiment of the present invention, optionally, the heat exchange device 1 includes a heat exchanger 13, a first pipe 14 and a second pipe 15; the first end of the first pipe 14 is connected to the air inlet of the waste heat gas to be recovered, and the second end of the first pipe 14 is connected to the heat exchanger 13; the first end of the second pipe 15 is connected to the exhaust port of the waste heat gas to be recovered, and the second end of the second pipe 15 is connected to the heat exchanger 13; the waste heat gas to be recovered enters the heat exchanger 13 through the first pipe 14, and the heat exchanger 13 performs heat exchange on the waste heat gas to be recovered and then discharges the waste heat gas through the second pipe 15;

[0050] The second end of the heat exchanger 13 is provided with a first water outlet 131 and a first water inlet 132 , and the first water outlet 131 and the first water inlet 132 are connected to the heat pump device 2 .

[0051] In the embodiment of the present invention, normally open stop valves are provided on the first pipeline 14 and the second pipeline 15, and a normally closed stop valve is provided between the first pipeline 14 and the second pipeline 15, so as to adjust and use them during maintenance.

[0052] In the embodiment of the present invention, optionally, the heat exchanger 13 is a plate heat exchanger.

[0053] In the embodiment of the present invention, a heat exchange device 1 is arranged in the evaporative cooling area of ​​the system, and the pipeline of the waste heat gas to be recovered is connected, so that the waste heat of the waste heat gas to be recovered is transferred to the circulating water at the evaporation end of the low-temperature heat pump through heat exchange. Specifically, the heat in the waste heat gas to be recovered is transferred out by arranging a heat exchanger, and the plate heat exchanger has a large heat exchange surface area, and the flow mode of the fluid between the plates makes the heat transfer efficiency high, which can achieve a good heat exchange effect and has a small size and light weight, saving installation space.

[0054] The heat pump device 2 includes: a low-temperature heat pump 21 and a high-temperature heat pump 22, the low-temperature heat pump 21 and the high-temperature heat pump 22 are connected in series, the first end of the low-temperature heat pump 21 is connected to the second end of the heat exchange device 1, the second end of the low-temperature heat pump 21 is connected to the first end of the high-temperature heat pump 22, and the second end of the high-temperature heat pump 22 is connected to the energy storage device 3;

[0055] In the embodiment of the present invention, optionally, the heat pump device 2 further includes: a third pipeline 23, a fourth pipeline 24, a fifth pipeline 25, a sixth pipeline 26, a first water pump group 27 and a second water pump group 28;

[0056] The first end of the third pipe 23 is connected to the first water outlet 131 of the heat exchange device 1, and the second end of the third pipe 23 is connected to the first end of the low-temperature heat pump 21; the first end of the fourth pipe 24 is connected to the first water inlet 132 of the heat exchange device 1, and the second end of the fourth pipe 24 is connected to the first end of the low-temperature heat pump 21;

[0057] The first end of the fifth pipeline 25 is connected to the second end of the low-temperature heat pump 21, and the second end of the fifth pipeline 25 is connected to the first end of the high-temperature heat pump 22; the first end of the sixth pipeline 26 is connected to the second end of the low-temperature heat pump 21, and the second end of the sixth pipeline 26 is connected to the first end of the high-temperature heat pump 22;

[0058] The first water pump group 27 is arranged on the fourth pipeline 24 ; the second water pump group 28 is arranged on the fifth pipeline 25 .

[0059] In the embodiment of the present invention, the first water pump group and the second water pump group are optionally provided with three groups of water pumps, two of which are in-use water pumps, and one of which is a standby water pump. Each group of water pumps includes a water pump body, a check valve, a manual butterfly valve and a pressure gauge. In the water pump group, the water pump body is responsible for the delivery of the fluid, the check valve prevents backflow, the manual butterfly valve is used for flow regulation and cut-off, and the pressure gauge provides pressure monitoring to ensure the efficient, safe and stable operation of the water pump system, and each water pump group is also provided with a corresponding temperature transmitter, through which the temperature transmitter is used to monitor and protect the equipment in real time, improve the efficiency and reliability of the system, and ensure the safe and stable operation of the water pump.

[0060] In the embodiment of the present invention, a heat pump is provided to transfer heat from a low-temperature environment to a high-temperature environment using a small amount of electrical energy, thereby providing relatively more heat or cooling with less electrical energy, saving energy expenses, and providing uniform temperature control through the heat pump device, making the system more stable and efficient.

[0061] In the embodiment of the present invention, optionally, the low-temperature heat pump 21 includes a first evaporator 211 and a first condenser 212;

[0062] The first end of the first evaporator 211 is provided with a second water inlet 2111 and a second water outlet 2112, the second water inlet 2111 is connected to the heat exchange device 1 through the third pipe 23; the second water outlet 2112 is connected to the heat exchange device 1 through the fourth pipe 24; the second end of the first evaporator 211 is connected to the first end of the first condenser 212;

[0063] The second end of the first condenser 212 is provided with a third water outlet 2121 and a third water inlet 2122 ; the third water outlet 2121 is connected to the high-temperature heat pump 22 through a fifth pipe 25 ; the third water inlet 2122 is connected to the high-temperature heat pump 22 through a sixth pipe 26 .

[0064] In the embodiment of the present invention, optionally, the high temperature heat pump includes a second evaporator 221 and a second condenser 222;

[0065] The first end of the second evaporator 221 is provided with a fourth water inlet 2211 and a fourth water outlet 2212, the fourth water inlet 2211 is connected to the low-temperature heat pump 21 through the fifth pipe 25; the fourth water outlet 2212 is connected to the low-temperature heat pump 21 through the sixth pipe 26; the second end of the second evaporator 221 is connected to the first end of the second condenser 222;

[0066] The second end of the second condenser 222 is provided with a fifth water outlet 2221 and a fifth water inlet 2222 ; the fifth water outlet 2221 and the fifth water inlet 2222 are connected to the energy storage device 3 .

[0067] In the embodiment of the present invention, a small amount of electric energy is input into the low-temperature heat pump 21 so that the low-temperature heat pump 21 absorbs the heat at the evaporation end and releases it to the circulating water at the condensation end. Electric energy is then input into the high-temperature heat pump 22 so that the high-temperature heat pump absorbs the heat at the evaporation end and releases it to the condensation end, thereby finally achieving the goal of heating the thermal water. The water pump group and the outlet temperature are controlled by PID (Proportional Integral Derivative). Specifically, the outlet temperature of the condensation end of the high-temperature heat pump 22 can be set to 95°C according to actual conditions, thereby discharging water at a constant temperature and reducing the steam consumption of the package.

[0068] Specifically, the heat pump device adopts a low-temperature heat pump and a high-temperature heat pump connected in series. Both the high and low-temperature heat pumps adopt the form of dual compressors. Each compressor has 4 energy levels, namely 25%, 50%, 75%, and 100%. When the waste heat load of the waste heat gas to be recovered is small, the heat pump can also be adjusted to a small load according to actual needs. When the waste heat of the waste heat gas to be recovered is large, the heat pump can also be adjusted to a large load according to actual needs, fully responding to changes in load, and the adjustment range is wider; by setting the heat pump to adjust the energy according to the temperature of the evaporation end, dual control of the temperature of the evaporation end and the condensation end of the heat pump is achieved, the system operates more stably and efficiently, and finally the waste heat of the waste heat gas to be recovered is transferred to the energy storage water system, so as to achieve the goal of comprehensive utilization of waste heat.

[0069] The water replenishing device 4 is connected to the heat pump device 2 and the energy storage device 3 respectively to replenish water into the heat pump device 2 and the heat exchange device 1 .

[0070] In the embodiment of the present invention, a heat exchange device, a heat pump device, an energy storage device and a water replenishing device are provided; the first end of the heat exchange device is provided with a first air inlet and a first air outlet; the waste heat gas to be recovered enters the heat exchange device from the first air inlet of the first end of the heat exchange device, and is discharged from the first air outlet after circulating inside the heat exchange device; the second end of the heat exchange device is connected to the heat pump device; the heat pump device includes: a low-temperature heat pump and a high-temperature heat pump, the low-temperature heat pump and the high-temperature heat pump are connected in series, the first end of the low-temperature heat pump is connected to the second end of the heat exchange device, the second end of the low-temperature heat pump is connected to the first end of the high-temperature heat pump, and the second end of the high-temperature heat pump is connected to the energy storage device; the water replenishing device is connected to the heat pump device and the energy storage device respectively, and water is replenished to the heat pump device and the heat exchange device. The waste heat of the gas is recovered and utilized, and the energy storage water is heated for use in subsequent steps, so as to maximize the utilization of waste heat, achieve significant energy-saving effects, and solve the problem of the existing lack of efficient waste heat recovery system.

[0071] In the embodiment of the present invention, optionally, the energy storage device 3 includes: a seventh pipeline 31, an eighth pipeline 32, a third water pump group 33 and an energy storage water tank 34;

[0072] The first end of the seventh pipe 31 is connected to the fifth water outlet 2221 of the high-temperature heat pump 22, and the second end of the seventh pipe 31 is connected to the first end of the energy storage water tank 34;

[0073] The first end of the eighth pipe 32 is connected to the fifth water inlet 2222 of the high-temperature heat pump 22, and the second end of the eighth pipe 32 is connected to the second end of the energy storage water tank 34; wherein the first end of the energy storage water tank 34 is located higher than the second end;

[0074] The third water pump group 33 is arranged on the eighth pipeline 32 .

[0075] In the embodiment of the present invention, the third water pump group 33 is provided with two groups of water pumps, one of which is a water pump in use, and the other is a standby water pump. Each group of water pumps includes a water pump body, a check valve, a manual butterfly valve and a pressure gauge. In the water pump group, the water pump body is responsible for the delivery of the fluid, the check valve prevents backflow, the manual butterfly valve is used for flow regulation and cut-off, and the pressure gauge provides pressure monitoring to ensure the efficient, safe and stable operation of the water pump system, and each water pump group is also provided with a corresponding temperature transmitter, through which the temperature transmitter is used to monitor and protect the equipment in real time, improve the efficiency and reliability of the system, and ensure the safe and stable operation of the water pump.

[0076] In the embodiment of the present invention, at least one water storage layer is provided in the energy storage water tank 34, and the water storage layers are arranged in descending order of temperature, that is, the energy storage water with the highest temperature or the energy storage water just delivered is placed in the upper layer, and the energy storage water with low temperature or decreased temperature is placed in the lower layer, so that the energy storage water in the energy storage device that does not meet the preset temperature requirements can be subsequently input into the high-temperature heat pump for circulation and reheated to realize energy circulation.

[0077] In the embodiment of the present invention, optionally, the energy storage device further includes: a ninth pipeline 35, a pneumatic butterfly valve 36 and a temperature transmitter 37;

[0078] The ninth pipeline is arranged between the seventh pipeline and the eighth pipeline; a pneumatic butterfly valve is arranged on the ninth pipeline;

[0079] The temperature transmitter is arranged on one end of the seventh pipe close to the energy storage water tank.

[0080] In the embodiment of the present invention, a pneumatic butterfly valve is provided which utilizes a pneumatic drive device to control fluid flow, can realize flow control and opening and closing functions, and provides a flexible operation mode in the automation system; and a corresponding temperature transmitter is provided, through which the temperature transmitter is used to monitor and protect the equipment in real time, thereby improving the efficiency and reliability of the system and ensuring the safe and stable operation of the water pump.

[0081] In the embodiment of the present invention, optionally, the water replenishing device 4 includes: a tenth pipeline 41, an eleventh pipeline 42 and an expansion water tank 43;

[0082] A first end of the tenth pipe 41 is connected to the expansion water tank 43, and a second end of the tenth pipe 41 is connected to the fourth pipe 24;

[0083] A first end of the eleventh pipe 42 is connected to the expansion water tank 43 , and a second end of the eleventh pipe 42 is connected to the fifth pipe 25 .

[0084] In the embodiment of the present invention, the expansion water tank 43 replenishes water to the heat pump device 2 and the heat exchange device 1. The expansion water tank 43 compensates for temperature changes, stabilizes pressure, and adjusts water levels, thereby effectively managing the amount of water and pressure in the system to ensure safe, stable, and efficient operation of the system.

[0085] Please refer to Figure 2 The embodiment of the present invention provides a waste heat recovery method, which is applied as follows Figure 1 The waste heat recovery system described in any one of the preceding claims, the method comprising:

[0086] Step S21: the waste heat gas to be recovered is input into the heat exchange device from the first air inlet, the heat exchange device performs heat exchange on the waste heat gas to be recovered, the heat exchange water in the heat exchange device enters the heat pump device from the first water outlet, and the waste heat gas to be recovered after heat exchange is discharged from the first air outlet;

[0087] Step S22: inputting the hot water to the low-temperature heat pump in the heat pump device for a first heat exchange to obtain low-temperature water; then inputting the low-temperature water to the high-temperature heat pump for a second heat exchange to obtain high-temperature water;

[0088] Step S23: inputting the high-temperature water into the energy storage water tank for storage, and inputting the energy storage water in the energy storage device that does not meet the preset temperature requirement into the high-temperature heat pump for circulation and reheating;

[0089] Step S24: using a water replenishing device to replenish water to the heat exchange device and the heat pump device.

[0090] In the embodiment of the present invention, the waste heat gas to be recovered is input into the heat exchange device from the first air inlet, the heat exchange device performs heat exchange on the waste heat gas to be recovered, the heat exchange water in the heat exchange device after heat exchange enters the heat pump device from the first water outlet, and the waste heat gas to be recovered after heat exchange is discharged from the first air outlet; the heat exchange water is input into the low-temperature heat pump in the heat pump device for the first heat exchange to obtain low-temperature water; the low-temperature water is then input into the high-temperature heat pump for the second heat exchange to obtain high-temperature water; the high-temperature water is input into the energy storage water tank for storage, and the energy storage water in the energy storage device that does not meet the preset temperature requirements is input into the high-temperature heat pump for circulation and reheating; the water replenishment device is used to replenish water to the heat exchange device and the heat pump device. The waste heat of the gas is recovered and utilized, and the energy storage water is heated for use in subsequent steps, so as to maximize the utilization of waste heat, achieve significant energy-saving effects, and solve the problem of the existing lack of efficient waste heat recovery system.

[0091] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0092] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0093] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A waste heat recovery system, characterized in that: include: Heat exchange devices, heat pump devices, energy storage devices and water replenishment devices; The first end of the heat exchange device is provided with a first air inlet and a first air outlet; The waste heat gas to be recovered enters the heat exchange device from the first air inlet at the first end of the heat exchange device, circulates inside the heat exchange device, and is discharged from the first air outlet at the first end of the heat exchange device; The second end of the heat exchange device is connected to the heat pump device; The heat pump device comprises: a low-temperature heat pump and a high-temperature heat pump, wherein the low-temperature heat pump and the high-temperature heat pump are connected in series, a first end of the low-temperature heat pump is connected to a second end of the heat exchange device, a second end of the low-temperature heat pump is connected to a first end of the high-temperature heat pump, and a second end of the high-temperature heat pump is connected to the energy storage device; The water replenishing device is connected to the heat pump device and the energy storage device respectively to replenish water into the heat pump device and the heat exchange device.

2. The waste heat recovery system according to claim 1, characterized in that: The heat exchange device comprises a heat exchanger, a first pipe and a second pipe; the first end of the first pipe is connected to the air inlet of the waste heat gas to be recovered, and the second end of the first pipe is connected to the heat exchanger; the first end of the second pipe is connected to the exhaust port of the waste heat gas to be recovered, and the second end of the second pipe is connected to the heat exchanger; the waste heat gas to be recovered enters the heat exchanger through the first pipe, and the heat exchanger performs heat exchange on the waste heat gas to be recovered and then discharges the waste heat gas through the second pipe; The second end of the heat exchanger is provided with a first water outlet and a first water inlet, and the first water outlet and the first water inlet are connected to the heat pump device.

3. The waste heat recovery system according to claim 2, characterized in that: The heat exchanger is a plate heat exchanger.

4. The waste heat recovery system according to claim 2, characterized in that: The heat pump device further comprises: a third pipeline, a fourth pipeline, a fifth pipeline, a sixth pipeline, a first water pump group and a second water pump group; The first end of the third pipeline is connected to the first water outlet of the heat exchange device, and the second end of the third pipeline is connected to the first end of the low-temperature heat pump; the first end of the fourth pipeline is connected to the first water inlet of the heat exchange device, and the second end of the fourth pipeline is connected to the first end of the low-temperature heat pump; The first end of the fifth pipeline is connected to the second end of the low-temperature heat pump, and the second end of the fifth pipeline is connected to the first end of the high-temperature heat pump; the first end of the sixth pipeline is connected to the second end of the low-temperature heat pump, and the second end of the sixth pipeline is connected to the first end of the high-temperature heat pump; The first water pump group is arranged on the fourth pipeline; the second water pump group is arranged on the fifth pipeline.

5. The waste heat recovery system according to claim 4, characterized in that: The low temperature heat pump comprises a first evaporator and a first condenser; The first end of the first evaporator is provided with a second water inlet and a second water outlet, the second water inlet is connected to the heat exchange device through the third pipe; the second water outlet is connected to the heat exchange device through the fourth pipe; the second end of the first evaporator is connected to the first end of the first condenser; The second end of the first condenser is provided with a third water outlet and a third water inlet; the third water outlet is connected to the high-temperature heat pump through the fifth pipe; the third water inlet is connected to the high-temperature heat pump through the sixth pipe.

6. The waste heat recovery system according to claim 4, characterized in that: The high temperature heat pump comprises a second evaporator and a second condenser; The first end of the second evaporator is provided with a fourth water inlet and a fourth water outlet, the fourth water inlet is connected to the low-temperature heat pump through the fifth pipe; the fourth water outlet is connected to the low-temperature heat pump through the sixth pipe; the second end of the second evaporator is connected to the first end of the second condenser; The second end of the second condenser is provided with a fifth water outlet and a fifth water inlet; the fifth water outlet and the fifth water inlet are connected to the energy storage device.

7. The waste heat recovery system according to claim 6, characterized in that: The energy storage device comprises: a seventh pipeline, an eighth pipeline, a third water pump group and an energy storage water tank; The first end of the seventh pipeline is connected to the fifth water outlet of the high-temperature heat pump, and the second end of the seventh pipeline is connected to the first end of the energy storage water tank; The first end of the eighth pipeline is connected to the fifth water inlet of the high-temperature heat pump, and the second end of the eighth pipeline is connected to the second end of the energy storage water tank; wherein the first end of the energy storage water tank is located higher than the second end; The third water pump group is arranged on the eighth pipeline.

8. The waste heat recovery system according to claim 7, characterized in that: The energy storage device further comprises: a ninth pipeline, a pneumatic butterfly valve and a temperature transmitter; The ninth pipeline is arranged between the seventh pipeline and the eighth pipeline; a pneumatic butterfly valve is arranged on the ninth pipeline; The temperature transmitter is arranged on one end of the seventh pipeline close to the energy storage water tank.

9. The waste heat recovery system according to claim 7, characterized in that: The first water pump group and the second water pump group are provided with three groups of water pumps, two of which are in-use water pumps, and one of which is a standby water pump; the third water pump group is provided with two groups of water pumps, one of which is in-use water pump, and the other is a standby water pump.

10. The waste heat recovery system according to claim 4, characterized in that: The water replenishing device comprises: a tenth pipeline, an eleventh pipeline and an expansion water tank; The first end of the tenth pipeline is connected to the expansion water tank, and the second end of the tenth pipeline is connected to the fourth pipeline; The first end of the eleventh pipe is connected to the expansion water tank, and the second end of the eleventh pipe is connected to the fifth pipe.

11. A waste heat recovery method, characterized in that: Using the waste heat recovery system according to any one of claims 1 to 10, the method comprises: The waste heat gas to be recovered is input into the heat exchange device from the first air inlet, the heat exchange device performs heat exchange on the waste heat gas to be recovered, the heat exchange water in the heat exchange device after heat exchange enters the heat pump device from the first water outlet, and the waste heat gas to be recovered after heat exchange is discharged from the first air outlet; The hot water is input into the low-temperature heat pump in the heat pump device for a first heat exchange to obtain low-temperature water; and the low-temperature water is then input into the high-temperature heat pump for a second heat exchange to obtain high-temperature water; Inputting the high-temperature water into the energy storage water tank for storage, and inputting the energy storage water in the energy storage device that does not meet the preset temperature requirement into the high-temperature heat pump for circulation and reheating; A water replenishing device is used to replenish water to the heat exchange device and the heat pump device.

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