Heat supply system based on waste heat of air compressor

Abstract

The utility model discloses a heat supply system based on waste heat of an air compressor, which comprises a first heat supply unit, a second heat supply unit, a water replenishing unit and a waste heat recovery unit, and is characterized in that the first heat supply unit comprises a circulation loop formed by sequentially connecting a heat pump unit, a circulation hot water supply pipeline, a first user side and a circulation hot water return pipeline; a hot air outlet of the air compressor is positioned at an air inlet of the heat pump unit; the waste heat recovery unit comprises a heat exchanger used for recovering heat of hot oil of the air compressor. The air source heat pump unit is used for recycling waste heat of hot exhaust air of the air compressor, the heat exchanger is used for recycling oil heat of the air compressor, and the waste heat recycling rate of the air compressor is increased; and the second heat supply unit is provided with two water tanks, cold water enters the heat exchanger from the first water tank, flows back to the second water tank after passing through the heat exchanger, and is supplemented into the first water tank, so that heat taking at any time of a second user side is realized, and the influence of water supplementing on heat consumption is reduced.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery technology, and in particular to a heating system based on waste heat from an air compressor. Background Technology

[0002] Compressed air, as the second largest power source after electricity, is widely used in various fields. Statistics show that air compressors consume 10% of industrial energy. During operation, air compressors generate a significant amount of heat due to air compression, mechanical friction, and motor heating. According to authoritative testing, only 10% of the electrical energy consumed by an air compressor is converted into the potential energy of compressed air, while the remaining 90% is converted into heat energy (nearly 85% of which can be recovered and reused). To ensure the normal and stable operation of the air compressor and maintain its normal operating temperature, this heat is usually released into the environment, causing energy waste and environmental thermal pollution. Therefore, the recovery and rational utilization of the heat generated during air compressor operation is crucial.

[0003] Using waste heat from air compressors for domestic hot water is the most common and effective energy-saving measure. Currently, common waste heat recovery systems for air compressors utilize waste heat recovery heat exchangers to recover heat. This involves connecting the air compressor via a bypass oil or air circuit to recover the heat it carries. A water pump then sends water from an insulated hot water tank to the waste heat recovery heat exchanger for heating. After heating, the water flows back to the insulated hot water tank, and the cycle continues until all the water in the tank reaches the specified temperature. Finally, a hot water supply pump delivers the hot water from the insulated hot water tank to the user.

[0004] The aforementioned circulating heating method has the following problems in actual operation: First, when replenishing water, cold water is generally directly added to the insulated water tank. This causes the hot water in the insulated water tank to cool down again, requiring reheating until all the water in the tank is heated to the specified temperature, which takes a considerable amount of time. During this period, it is impossible to provide hot water that meets the temperature requirements at any time. Secondly, this waste heat recovery method cannot completely replace the original cooling system of the air compressor in actual operation. Most of the waste heat is lost to the external environment through the air compressor's own cooling system, resulting in a low waste heat utilization rate. Therefore, how to provide hot water that meets the temperature requirements immediately and stably without affecting the stable operation of the air compressor, and how to maximize the utilization of the "free" heat from the air compressor's waste heat, has become an important technical issue in the field of air compressor waste heat recovery and utilization. Summary of the Invention

[0005] In view of this, this utility model proposes a heating system based on the waste heat of an air compressor, which greatly improves the utilization rate of the waste heat of the air compressor and enables hot water users to use heat at any time.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The present invention relates to a heating system based on waste heat from an air compressor. The heating system includes a first heating unit, a second heating unit, a water supply unit, and a waste heat recovery unit for recovering waste heat from the air compressor. The first heating unit includes a circulation loop consisting of a heat pump unit, a circulating hot water supply pipe, a first user terminal, and a circulating hot water return pipe connected in sequence. The heat pump unit is an air source heat pump unit or an air source-water source composite heat pump unit, and the hot air outlet of the air compressor is located at the air inlet of the heat pump unit.

[0008] The waste heat recovery unit includes a heat exchanger for recovering heat from the hot oil of the air compressor, and the heat exchanger and the air compressor form a hot oil circulation loop through pipelines;

[0009] The second heating unit includes a second user terminal, a first water tank, and a second water tank. The first water tank is connected to the water inlet of the heat exchanger via a cold water heating pipe. The water outlet of the heat exchanger is connected to the second water tank via a hot water heating pipe. The second water tank is connected to the second user terminal via a hot water supply pipe. The first water tank is connected to the hot water return pipe and the tap water pipe of the second user terminal.

[0010] The hot water supply pipeline is equipped with a hot water supply pump set, the cold water heating pipeline is equipped with a cold water pump set, and the circulating hot water supply pipeline is equipped with a circulating pump set; an eleventh valve is installed at the outlet of the tap water pipeline, and a ninth valve is installed at the inlet of the cold water heating pipeline.

[0011] The beneficial effects are: This utility model changes the traditional circulating air compressor waste heat recovery system, uses a heat pump unit (air source heat pump unit or composite heat pump unit with air source) to recover the waste heat of the air compressor exhaust air, and uses a heat exchanger to recover the oil heat of the air compressor, thereby improving the waste heat recovery and utilization rate of the air compressor.

[0012] The second heating unit of this utility model recovers the heat generated by the working oil of the air compressor through a heat exchanger. The second heating unit has two water tanks. Cold water enters the heat exchanger from the first water tank and flows back to the second water tank after passing through the heat exchanger. When replenishing water, it is directly added to the first water tank. The second water tank provides hot water to the second user in real time, thereby realizing the second user's heat access at any time and reducing the impact of water replenishment on the second user's heat use.

[0013] Preferably, the outlet end of the cold water heating pipe is further connected to a first branch pipe, which is connected to the outlet end of the circulating hot water return pipe. The first branch pipe is equipped with a third valve and a fifth valve connected in parallel with the third valve. The inlet of the hot water heating pipe is connected to the inlet end of the circulating hot water supply pipe via a second branch pipe, and the second branch pipe is equipped with a fourth valve and a sixth valve connected in parallel with the fourth valve. A first valve is installed on the cold water heating pipe located in front of the first branch pipe, and a second valve is installed on the hot water heating pipe located behind the second branch pipe. An eighth valve is installed on the circulating hot water supply pipe, and a seventh valve is installed on the circulating hot water return pipe. The beneficial effect is that this utility model utilizes the first and second branch pipes to achieve the connection between the cold water heating pipe, the hot water heating pipe, the circulating hot water return pipe, and the circulating hot water supply pipe. In actual operation, the system can not only use the waste heat from the exhaust air of the air compressor to provide heating for the first user, but also use the waste heat from the working oil of the air compressor to directly provide heating for the first user, thus improving the utilization rate of the waste heat from the working oil; it can also use the waste heat from the exhaust air of the air compressor to heat domestic water and provide domestic hot water for the second user, making the whole system more flexible.

[0014] Preferably, the water replenishment unit includes a softened water treatment pipe connected to tap water and a third water tank. The softened water treatment pipe is equipped with a softened water treatment device. The third water tank is connected to the circulating hot water return pipe through a water replenishment pipe, and a water replenishment pump set is installed on the water replenishment pipe.

[0015] Preferably, the water replenishment pump group, hot water supply pump group, cold water pump group, and circulation pump group are all in pairs or more. In this invention, each pump group consists of two or more units, allowing for one unit to be used as a backup or two units to be used as backups, ensuring the normal operation of the entire system and reducing downtime caused by malfunctions.

[0016] Preferably, the bottom outlet of the second water tank is connected to the cold water heating pipe via a pipe equipped with a tenth valve. When the water temperature in the second water tank drops to a certain temperature, the tenth valve can be opened to reheat the water in the second water tank, ensuring the temperature of domestic hot water for the second user.

[0017] Compared with existing technologies, this invention changes the traditional circulating air compressor waste heat recovery system. It utilizes a heat pump unit (air source heat pump unit or a combined heat pump unit with an air source) to recover the waste heat from the air compressor's exhaust air, and a heat exchanger to recover the oil heat from the air compressor, thus improving the waste heat recovery and utilization rate of the air compressor. For air source heat pump units or combined heat pump units with an air source, the higher the ambient temperature, the higher the energy efficiency of the air source heat pump. The waste heat temperature of the exhaust air from the air compressor can reach over 50°C, providing the air source heat pump unit with high-temperature hot air, significantly improving its energy efficiency. This invention combines an air compressor unit and an air source heat pump unit, improving the waste heat recovery and utilization rate of the air compressor, increasing the energy efficiency of the heat pump unit, reducing its operating energy consumption, reducing environmental pollution, and lowering the operating costs for enterprises.

[0018] The second heating unit of this utility model recovers the heat generated by the working oil of the air compressor through a heat exchanger. The second heating unit has two water tanks. Cold water enters the heat exchanger from the first water tank and flows back to the second water tank after passing through the heat exchanger. When replenishing water, it is directly added to the first water tank. The second water tank provides hot water to the second user in real time, thereby realizing the second user's heat access at any time and reducing the impact of water replenishment on the second user's heat use. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the pipeline of this utility model.

[0020] Figure 2 This diagram shows the operating condition where the waste heat from the air compressor's working oil and the waste heat from the hot exhaust air are both used in the second heating unit.

[0021] Figure 3 This diagram shows the operating condition where the waste heat from the air compressor's working oil and the waste heat from the hot exhaust air are both used in the first heating unit. Detailed Implementation

[0022] The embodiments of this utility model will be described in detail below with reference to the accompanying drawings. These embodiments are implemented based on the technical solution of this utility model and provide detailed implementation methods and specific operation processes. However, the protection scope of this utility model is not limited to the following embodiments.

[0023] It should be noted that in the description of this utility model, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0024] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0025] like Figure 1 As shown, the heating system based on the waste heat of the air compressor of this utility model includes a first heating unit, a second heating unit, a water replenishment unit, and a waste heat recovery unit for recovering the waste heat of the air compressor 301. The first heating unit includes a circulation loop formed by sequentially connecting a heat pump unit 101, a circulating hot water supply pipe 102, a first user terminal 103 (for heating or production), and a circulating hot water return pipe 104. The circulating hot water return pipe 104 is equipped with a circulation pump unit 105 to provide circulation power. The heat pump unit 101 is an air source heat pump unit or an air source-water source composite heat pump unit. An exhaust pipe 302 is provided at the hot air outlet of the air compressor 301, and the air outlet of the exhaust pipe 302 is directly opposite the air inlet of the heat pump unit 101. During operation, the heat pump unit 101 absorbs the cooling exhaust air from the air compressor 301 and indirectly transfers the heat of the cooling exhaust air to the softened water from the circulating hot water loop. The softened water absorbs heat and rises to 55℃~60℃, then is supplied to the first user terminal 103 via the circulating hot water supply pipe 102. The return water from the first user terminal 103 (temperature between 45℃~50℃) re-enters the heat pump unit 101 via the circulating hot water return pipe 104, thus achieving circulating heating. Because the ambient temperature at the air inlet of the heat pump unit 101 reaches as high as 50℃, the energy efficiency ratio and operating efficiency of the heat pump unit 101 are greatly improved, expanding the application range of air source heat pumps in northern regions and demonstrating significant environmental, social, and economic benefits.

[0026] The waste heat recovery unit includes a heat exchanger 303 for recovering heat from the hot oil in the air compressor 301. A hot oil circulation loop is formed between the heat exchanger 303 and the air compressor 301 via pipelines. The second heating unit, combined with the heat exchanger 303, provides domestic hot water to the second user. It includes the second user, a first water tank 201 (cold water tank), and a second water tank 202 (hot water tank, with an insulation layer). The first water tank 201 is connected to the heat exchanger 303 via a cold water heating pipe 207 (equipped with a cold water pump unit 203). The water outlet of the heat exchanger 303 is connected to the second water tank 202 via the hot water heating pipe 204. The second water tank 202 is connected to the second user terminal via the hot water supply pipe 205. A hot water supply pump set 206 is installed on the hot water supply pipe 205 to provide hot water to the second user terminal. The first water tank 201 is connected to the hot water return pipe and the tap water pipe of the second user terminal to achieve water replenishment. An eleventh valve F11 is installed at the outlet of the tap water pipe, and a ninth valve is installed at the inlet of the cold water heating pipe 207. During operation, cold water is added to the first water tank 201. The water in the first water tank 201 enters the heat exchanger 303 through the cold water heating pipe 207, absorbing the heat from the high-temperature working oil flowing through the heat exchanger 303. After absorbing the heat from the oil, the temperature of the cold water can rise to 60℃ and then enter the second water tank 202 through the hot water heating pipe 204. Then, it is supplied to the second user end through the hot water supply pipe 205 and the hot water supply pump set 206, ensuring the domestic hot water for the second user end. The second heating unit of this utility model has two water tanks. Cold water enters the heat exchanger 303 from the first water tank 201, and then flows back to the second water tank 202 after passing through the heat exchanger 303. When replenishing water, it is directly added to the first water tank 201. The second water tank 202 provides hot water to the second user end in real time, thereby realizing the second user end's heat access at any time and reducing the impact of water replenishment on the second user end's heat use.

[0027] The outlet end of the cold water heating pipe 207 is also connected to a first branch pipe 401, which is connected to the outlet end of the circulating hot water return pipe 104. The first branch pipe 401 is equipped with a third valve F3 and a fifth valve F5 connected in parallel with the third valve F3. The inlet of the hot water heating pipe 204 is connected to the inlet end of the circulating hot water supply pipe 102 through a second branch pipe 402, and the second branch pipe 402 is equipped with a fourth valve F4 and a sixth valve F6 connected in parallel with the fourth valve F4. The cold water heating pipe 207 located in front of the first branch pipe 401 is equipped with a first valve F1, and the hot water heating pipe 204 located behind the second branch pipe 402 is equipped with a second valve F2. The circulating hot water supply pipe 102 is equipped with an eighth valve F8, and the circulating hot water return pipe 104 is equipped with a seventh valve F7. This utility model utilizes the first branch pipe 401 and the second branch pipe 402 to connect the cold water heating pipe 207, the hot water heating pipe 204 with the circulating hot water return pipe 104 and the circulating hot water supply pipe 102.

[0028] In actual operation, the waste heat from the exhaust air of the air compressor 301 can be used to heat the first user terminal 103, and the waste heat from the working oil of the air compressor 301 can also be used to directly heat the first user terminal 103, improving the utilization rate of the waste heat from the working oil; the waste heat from the exhaust air of the air compressor 301 can also be used to heat domestic water to provide domestic hot water for the second user terminal, further improving the recovery and utilization rate of waste heat from the air compressor 301, realizing efficient use of energy, reducing the consumption of electricity and fossil energy, and helping to reduce environmental pollution and lower the operating costs of enterprises.

[0029] In actual operation, if the second water tank 202 is full and the hot water temperature reaches 60℃, heating of the cold water can be stopped, and the heat from the high-temperature working oil can be used for the first user terminal 103 to meet its heating needs. The specific working process is as follows: First valve F1, second valve F2, third valve F3, and fourth valve F4 are closed; sixth valve F6, eighth valve F8, seventh valve F7, and fifth valve F5 are opened. The outlet of the circulating hot water return pipe 104 is divided into two paths: one path directly enters the heat pump unit 101, and then enters the circulating hot water supply pipe 102 via the heat pump unit 101; the other path enters the heat exchanger 303 via the fifth valve F5. The hot water from the heat exchanger 303 enters the circulating hot water supply pipe 102 via the sixth valve F6. The hot water from the heat pump unit 101 also flows into the circulating hot water supply pipe 102, achieving simultaneous heating of the waste heat from the working oil of the air compressor 301 and the waste heat from the hot exhaust air. See details... Figure 3 .

[0030] During off-peak electricity hours or when rapid heat extraction is needed, the heat pump unit 101 and heat exchanger 303 can be used together to produce domestic hot water: Open valves F1, F2, F3, and F4, and close valves F5, F6, F7, and F8. The cold water from the first water tank 201 splits into two streams: one stream enters the heat exchanger 303, and after heat exchange, flows through the hot water heating pipe 204 into the second water tank 202; the other stream enters the heat pump unit 101 through the first branch pipe 401 (where valve F3 is located), and after heat exchange, flows through the fourth valve F4 and the second branch pipe 402, converging into the hot water heating pipe 204. This achieves efficient heating. See details... Figure 2

[0031] Combination Figure 1 It is known that the water replenishment unit includes a softened water treatment pipe 501 connected to tap water and a third water tank 502 (which is a water replenishment tank). The softened water treatment pipe 501 is equipped with a softened water treatment device. The third water tank 502 is connected to the circulating hot water return pipe 104 through a water replenishment pipe 503. A water replenishment pump group 504 is installed on the water replenishment pipe 503 to provide water replenishment power.

[0032] In actual installation, there are two (or more) sets of water supply pump 504, hot water supply pump 206, cold water pump 203 and circulation pump 105. Each pump set can be used as a backup to ensure the normal operation of the entire system.

[0033] As shown in the diagram, the bottom outlet of the second water tank 202 is connected to the cold water heating pipe 207 via a pipe equipped with a tenth valve F10. When the water temperature in the second water tank 202 drops to a certain level, the tenth valve F10 can be opened to reheat the water in the second water tank 202, ensuring the temperature of domestic hot water for the second user.

[0034] In actual installation, the makeup water pump set 504, hot water supply pump set 206, cold water pump set 203, and circulation pump set 105 use the same pump set. Taking the makeup water pump set 504 as an example: the makeup water pump set 504 includes a water pump, and a butterfly valve and a filter are installed on the inlet side of the water pump. A check valve and a butterfly valve are installed on its outlet side. See details... Figure 1 .

[0035] In actual installation, the circulating hot water return pipe 104 and the circulating hot water supply pipe 102 are connected by a pressure regulating branch, and a pressure regulating valve 106 is installed on the pressure regulating branch to balance the pressure between the inlet and outlet water; the first valve F1 to the eleventh valve F11 are all electric butterfly valves.

[0036] Finally, it should be emphasized that the above description is merely a preferred embodiment of this utility model and is not intended to limit this utility model. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still make modifications to the technical solutions described in the foregoing embodiments without creative effort, or make equivalent substitutions for some of the technical features. Therefore, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A heating system based on waste heat from an air compressor, characterized in that: The heating system includes a first heating unit, a second heating unit, a water replenishment unit, and a waste heat recovery unit for recovering waste heat from the air compressor. The circulating heating unit includes a circulating loop consisting of a heat pump unit, a circulating hot water supply pipe, a first user terminal, and a circulating hot water return pipe connected in sequence. The heat pump unit is an air source heat pump unit or an air source-water source composite heat pump unit, and the hot air outlet of the air compressor is located at the air inlet of the heat pump unit. The waste heat recovery unit includes a heat exchanger for recovering heat from the hot oil of the air compressor, and the heat exchanger and the air compressor form a hot oil circulation loop through pipelines; The second heating unit includes a second user terminal, a first water tank, and a second water tank. The first water tank is connected to the water inlet of the heat exchanger via a cold water heating pipe. The water outlet of the heat exchanger is connected to the second water tank via a hot water heating pipe. The second water tank is connected to the second user terminal via a hot water supply pipe. The first water tank is connected to the hot water return pipe and the tap water pipe of the second user terminal. The hot water supply pipeline is equipped with a hot water supply pump set, the cold water heating pipeline is equipped with a cold water pump set, and the circulating hot water return pipeline is equipped with a circulating pump set; an eleventh valve is installed at the outlet of the tap water pipeline, and a ninth valve is installed at the inlet of the cold water heating pipeline.

2. The heating system based on waste heat from an air compressor according to claim 1, characterized in that: The outlet end of the cold water heating pipe is also connected to a first branch pipe, which is connected to the outlet end of the circulating hot water return pipe. The first branch pipe is equipped with a third valve and a fifth valve connected in parallel with the third valve. The inlet of the hot water heating pipe is connected to the inlet of the circulating hot water supply pipe through a second branch pipe, and a fourth valve and a sixth valve connected in parallel with the fourth valve are provided on the second branch pipe. A first valve is installed on the cold water heating pipe located in front of the first branch pipe, and a second valve is installed on the hot water heating pipe located behind the second branch pipe; an eighth valve is installed on the circulating hot water supply pipe, and a seventh valve is installed on the circulating hot water return pipe.

3. The heating system based on waste heat from an air compressor according to claim 1, characterized in that: The water replenishment unit includes a softened water treatment pipe connected to tap water and a third water tank. The softened water treatment pipe is equipped with a softened water treatment device. The third water tank is connected to the circulating hot water return pipe through a water replenishment pipe, and a water replenishment pump set is installed on the water replenishment pipe.

4. The heating system based on waste heat from an air compressor according to claim 3, characterized in that: The water replenishment pump set, hot water supply pump set, cold water pump set, and circulation pump set are all in two or more sets.

5. The heating system based on waste heat from an air compressor according to claim 1, characterized in that: The bottom outlet of the second water tank is connected to the cold water heating pipe via a pipe with a tenth valve.

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