Heat pump unit system for recovering heat energy of oilfield produced water

Abstract

The utility model discloses an oilfield produced water heat energy recovery heat pump unit system, relates to the technical field of produced water heat recovery, aims to solve the problem of how to recycle heat in produced water, and comprises a hot water tank and a heat source water tank, the input end of the hot water tank is communicated with a conveying pipeline for conveying produced water through an input pipe, and the input end and the output end of the heat source water tank are respectively communicated with the conveying pipeline through a heat source pipe and an output pipe; a non-metal collector I and a non-metal collector II are respectively mounted in the hot water tank and the heat source water tank; the system further comprises a heat exchange unit, the first non-metal collector is communicated with a condenser in the heat exchange unit, and the second non-metal collector is communicated with an evaporator in the unit.

Description

Technical Field

[0001] This utility model relates to the technical field of produced water heat recovery, specifically to a heat pump unit system for producing water heat energy recovery in oil fields. Background Technology

[0002] Produced water in oilfields refers to the water injected into the oil-bearing reservoir using the water injection method as oil extraction progresses and the oil content decreases. Produced water, carried out from the oil reservoir, has a high temperature. With advancements in produced water treatment technology, it can still be utilized even when treated to around 40°C. However, under traditional treatment processes, this is primarily a problem during the discharge of treated produced water; the temperature remains around 40°C after treatment, resulting in significant energy waste. Furthermore, produced water has a complex composition, containing chemicals, organic matter, microorganisms, and floating oil, which conventional heat exchangers struggle to handle. Even occasional maintenance and repairs incur economic losses for oilfields employing tens of thousands of workers. Considering the high density of workers in oilfield enterprises, there is a substantial energy demand for producing hot water.

[0003] Therefore, how to avoid huge energy waste, make full use of recyclable heat, and closely integrate it with the large demand for hot water production has become a major issue. Utility Model Content

[0004] To address the aforementioned problem of how to recover and reuse heat from produced water, this invention proposes a heat pump unit system for recovering heat energy from produced water in oilfields. The system includes a hot water tank and a heat source tank. The input end of the hot water tank is connected to a transport pipeline for conveying produced water via an input pipe. The input and output ends of the heat source tank are also connected to the transport pipeline via heat source pipes and output pipes, respectively. Non-metallic collector I and non-metallic collector II are respectively installed inside the hot water tank and the heat source tank. The system also includes a heat exchange unit. Non-metallic collector I is connected to the condenser within the heat exchange unit, and non-metallic collector II is connected to the evaporator within the heat exchange unit.

[0005] A further feature of this invention is that a hot water circulation pump is installed on the first non-metallic collector, and a heat source water circulation pump is installed on the second non-metallic collector.

[0006] A further feature of this invention is that a valve is installed on the input pipe.

[0007] A further feature of this invention is that the input pipe is located upstream of the heat source pipe, and the output pipe is located downstream of the heat source pipe.

[0008] A further feature of this invention is that the first non-metallic collector and the hot water tank are both submerged, and the second non-metallic collector and the heat source water tank are also both submerged.

[0009] This utility model also proposes a heat pump unit system for recovering heat energy from produced water in oilfields, which includes at least two hot water tanks and a heat source tank. The input ends of multiple hot water tanks are connected to a conveying pipeline for transporting produced water through input pipes. The multiple hot water tanks are connected in series. The input end and output end of the heat source tank are also connected to the conveying pipeline through heat source pipes and output pipes, respectively. A non-metallic collector I is installed in each hot water tank, and a non-metallic collector II is installed in each heat source tank corresponding to each hot water tank. A heat exchange unit is also installed in each hot water tank. The non-metallic collector I is connected to the condenser in the heat exchange unit, and the non-metallic collector II is connected to the evaporator in the heat exchange unit.

[0010] A further feature of this invention is that a hot water circulation pump is installed on the first non-metallic collector, and a heat source water circulation pump is installed on the second non-metallic collector.

[0011] A further feature of this invention is that a valve is installed on the input pipe.

[0012] A further feature of this invention is that the input pipe is located upstream of the heat source pipe, and the output pipe is located downstream of the heat source pipe.

[0013] A further feature of this invention is that the first non-metallic collector and the hot water tank are both submerged, and the second non-metallic collector and the heat source water tank are also both submerged.

[0014] A further feature of this invention is that an electromagnetic valve is installed on the connecting pipe between two adjacent hot water tanks.

[0015] A further feature of this invention is that, except for the first-stage hot water tank, all other hot water tanks are connected to the input pipe via a level valve.

[0016] The beneficial effects of this utility model are as follows:

[0017] 1. The heat source water tank can remove heat from the extracted water, and then the heat is transferred to the hot water tank through a heat exchange unit. This heat is then heated in the hot water tank, raising its temperature. The heated extracted water can then be reused, achieving heat recovery and reuse, reducing energy consumption and waste. It also reduces the environmental pollution caused by high-temperature water.

[0018] 2. The non-metallic water collectors 1 and 2 are installed in the hot water tank and heat source water tank in an immersion manner, which can prevent the collected water from directly contacting the inside of the heat exchange or circulation pipes. The collected water is isolated to the outside, which fundamentally eliminates the possibility of blockage and corrosion.

[0019] 3. By setting up at least two hot water tanks, tiered heating can be achieved. This means that multiple hot water tanks heat the water step-by-step until the last tank is heated to a predetermined stable temperature. This reduces the temperature load on each hot water tank and the heat exchange unit, improves their initial operating conditions, optimizes energy efficiency, and increases overall heat exchange efficiency. It also helps extend the service life of the heat exchange unit. Attached Figure Description

[0020] Figure 1 A schematic diagram of the structure of Embodiment 1 is shown.

[0021] Figure 2 A schematic diagram of the structure of Embodiment 2 is shown.

[0022] Attached reference numerals: 1. Hot water tank; 11. Non-metallic collector one; 111. Hot water circulation pump; 2. Heat source water tank; 21. Non-metallic collector two; 211. Heat source water circulation pump; 3. Inlet pipe; 31. Valve; 4. Delivery pipe; 5. Heat source pipe; 6. Outlet pipe; 7. Heat exchanger unit; 71. Condenser; 72. Evaporator; 8. Solenoid valve; 9. Liquid level valve. Detailed Implementation

[0023] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0024] Example 1

[0025] This invention proposes a heat pump unit system for recovering heat energy from produced water in oilfields, including a hot water tank 1 and a heat source water tank 2, both of which are sealed rectangular boxes. The input end of the hot water tank 1 is connected to a delivery pipeline 4 for transporting produced water via an input pipe 3, allowing the produced water in the delivery pipeline 4 to flow into the hot water tank 1 along the input pipe 3. The output end of the hot water tank 1 is used to connect to a water-using unit.

[0026] A valve 31 is installed on the input pipe 3. The valve 31 is a stop valve and can be used to control the on / off state of the input pipe 3.

[0027] The input and output ends of the heat source water tank 2 are connected to the delivery pipeline 4 via the heat source pipe 5 and the output pipe 6, respectively. The extracted water in the delivery pipeline 4 can flow into the heat source water tank 2 through the heat source pipe 5, and the water in the heat source water tank 2 can flow back into the delivery pipeline 4 through the output pipe 6. It should be noted that both the heat source pipe 5 and the output pipe 6 are equipped with normally open shut-off valves for use in closing the heat source pipe 5 and the output pipe 6 during maintenance.

[0028] The connection point between the input pipe 3 and the delivery pipe 4 is located upstream of the heat source pipe 5, and the connection point between the output pipe 6 and the delivery pipe 4 is located downstream of the heat source pipe 5. This prevents the extracted water after heat exchange in the heat source water tank from flowing into the hot water tank, further improving the heat utilization rate in the hot water tank. At the same time, the extracted water after heat exchange in the heat source water tank 2 is still discharged along the original delivery pipe 4, without affecting the original process.

[0029] Non-metallic collector 11 and non-metallic collector 21 are installed in hot water tank 1 and heat source water tank 2 respectively, and both non-metallic collector 11 and non-metallic collector 21 are installed in hot water tank 1 and heat source water tank 2 by immersion installation.

[0030] It also includes a heat exchange unit 7, which contains a heat exchange system comprising a condenser 71, an evaporator 72, a compressor, and an expansion valve, all connected in series in a circulation pipeline. Non-metallic collector 11 is connected to the condenser 71, and non-metallic collector 21 is connected to the evaporator 72. A hot water circulation pump 111 is installed on non-metallic collector 11, and a heat source water circulation pump 211 is installed on non-metallic collector 21, to respectively circulate the heat exchange medium within non-metallic collector 11 and non-metallic collector 21.

[0031] During operation, the extracted water in the delivery pipe 4 flows into the hot water tank 1 and the heat source water tank 2 via the input pipe 3 and the heat source pipe 5, respectively, with both entering the hot water tank 1 and the heat source water tank 2 at a temperature of 40°C. Then, under the action of the non-metallic collector 21, the temperature of the extracted water in the heat source water tank 2 is transferred to the evaporator 72. In the evaporator 72, the refrigerant absorbs heat and evaporates into gas, which then enters the compressor. After being compressed into high-temperature gas, it is sent to the condenser 71 for heat release. During heat release, the heat is transferred to the hot water tank 1 via the non-metallic heater 1, further heating the 40°C extracted water in the hot water tank 1. The further heated high-temperature extracted water in the hot water tank 1 is then delivered to the unit for its use from the output end of the hot water tank 1. Meanwhile, the extracted water in the heat source water tank 2, after heat exchange, is discharged back into the delivery pipe 4 via the output pipe 6, continuing its discharge along the original route.

[0032] Example 2

[0033] This embodiment proposes a heat pump unit system for recovering produced water in oilfields, including two hot water tanks 1 and one heat source tank 2. The input ends of the two hot water tanks 1 are connected to a delivery pipe 4 for transporting produced water via an input pipe 3, so that the produced water in the delivery pipe 4 can flow into the hot water tanks 1 along the delivery pipe 4. The two hot water tanks 1 are connected in series, and the output end of the last hot water tank 1 is used to connect to the unit.

[0034] A solenoid valve 8 is installed on the connecting pipe between the two hot water tanks 1. The solenoid valve 8 opens according to a set temperature; that is, when the water in the previous hot water tank 1 reaches the designated temperature, the solenoid valve 8 opens, and the water drawn from the previous hot water tank 1 flows into the next hot water tank 1. This prevents water from flowing into the next hot water tank 1 before it has reached the designated temperature. It should be noted that a check valve needs to be installed downstream of the solenoid valve 8 to prevent backflow of water from the lower hot water tank 1 and to prevent the water temperature in the lower hot water tank 1 from affecting the control of the solenoid valve 8.

[0035] Except for the first-stage hot water tank 1, all other hot water tanks 1 are connected to the input pipe 3 through the liquid level valve 9. That is, when the liquid level in the hot water tank 1 drops, the extracted water can be replenished to it through the input pipe 3, avoiding the problem that the previous hot water tank 1 cannot continue to replenish water if it does not reach the specified temperature, which would cause a serious water shortage in the next hot water tank 1.

[0036] It should be noted that the number of hot water tanks 1 in this application should be no less than two. This application only uses the installation of two hot water tanks 1 as an example. In actual use, the number of tanks installed is not limited to two. The number can be appropriately increased or decreased according to actual usage needs.

[0037] A valve 31 is installed on the input pipe 3. The valve 31 is a stop valve and can be used to control the on / off state of the input pipe 3.

[0038] The input and output ends of the heat source water tank 2 are connected to the delivery pipeline 4 via the heat source pipe 5 and the output pipe 6, respectively. The extracted water in the delivery pipeline 4 can flow into the heat source water tank 2 through the heat source pipe 5, and the water in the heat source water tank 2 can flow back into the delivery pipeline 4 through the output pipe 6. It should be noted that both the heat source pipe 5 and the output pipe 6 are equipped with normally open shut-off valves for use in closing the heat source pipe 5 and the output pipe 6 during maintenance.

[0039] The connection point between the input pipe 3 and the delivery pipe 4 is located upstream of the heat source pipe 5, and the connection point between the output pipe 6 and the delivery pipe 4 is located downstream of the heat source pipe 5. This prevents the extracted water after heat exchange in the heat source water tank from flowing into the hot water tank, further improving the heat utilization rate in the hot water tank. At the same time, the extracted water after heat exchange in the heat source water tank 2 is still discharged along the original delivery pipe 4, without affecting the original process.

[0040] The hot water tank is equipped with a non-metallic collector 11, and the heat source water tank 2 is equipped with two non-metallic collectors 21. The two non-metallic collectors 21 are respectively set to correspond to the two non-metallic collectors 11. Both the non-metallic collectors 11 and the non-metallic collectors 21 are installed in the hot water tank 1 and the heat source water tank 2 by immersion installation.

[0041] It also includes two heat exchange units 7, each corresponding to one of the two hot water tanks 1. Each heat exchange unit 7 contains a heat exchange system, including a condenser 71, an evaporator 72, a compressor, and an expansion valve, all connected in series in a circulation pipeline. Two non-metallic collectors 11 are connected to the condensers 71 in each of the two heat exchange units 7, and two non-metallic collectors 21 are connected to the evaporators 72 in each of the two heat exchange units 7. A hot water circulation pump 111 is installed on each of the non-metallic collectors 21, and a heat source water circulation pump 211 is installed on each of the non-metallic collectors 21, to circulate the heat exchange medium within the non-metallic collectors 11 and 21, respectively.

[0042] During operation, the extracted water in the delivery pipe 4 flows through the input pipe 3 and the heat source pipe 5 into the two hot water tanks 1 and 2, respectively, with the extracted water entering both tanks at 40°C. Then, under the action of the non-metallic collector 21, the temperature of the extracted water in the heat source tank 2 is transferred to the evaporator 72. In the evaporator 72, the refrigerant absorbs heat and evaporates into gas, which then enters the compressor. After being compressed into high-temperature gas, it is sent to the condenser 71 for heat release. During heat release, the heat is transferred to the hot water tank 1 through the non-metallic heater 1, further heating the 40°C extracted water in the hot water tank 1. The further heated high-temperature extracted water in the hot water tank 1 is then delivered from the output end of the hot water tank 1 to the unit for its use. Meanwhile, the extracted water in the heat source tank 2, after heat exchange, is discharged back into the delivery pipe 4 through the output pipe 6, continuing its discharge along the original route.

[0043] The two heat exchange units 7 can exchange heat with the non-metallic heaters 1 in the two hot water tanks 1 respectively, and further heat the two water tanks in stages, reducing the temperature rise load of individual heating.

[0044] In summary, this invention achieves the purpose of heat exchange in the extracted water through the heat source water tank 2, and then transfers the heat to the hot water tank 1 through the heat exchange unit 7. This heat is then heated in the hot water tank 1, raising its temperature, and the heated water is then utilized, achieving heat recovery and reuse, reducing energy consumption and waste. It also reduces the environmental pollution caused by high-temperature water. The non-metallic collector 11 and non-metallic collector 21 are submerged and installed in the hot water tank 1 and heat source water tank 2, preventing the extracted water from directly contacting the heat exchange or circulation pipes. The extracted water is isolated from these pipes, fundamentally eliminating the possibility of blockage and corrosion. By setting at least two hot water tanks 1, tiered heating can be achieved, with multiple hot water tanks 1 heating the water step by step until the last hot water tank 1 is heated to a predetermined stable temperature. This reduces the temperature load on each hot water tank 1 and the heat exchange unit 7, improves their initial operating conditions, optimizes energy efficiency, and increases overall heat exchange efficiency. At the same time, it also helps to extend the service life of heat exchanger unit 7.

[0045] Although the present invention has been described with reference to preferred embodiments, various modifications can be made to it and components can be replaced with equivalents without departing from the scope of the present invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0046] In the description of this utility model, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," which indicate direction or positional relationships, are based on the direction or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0047] Furthermore, it should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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 according to the specific circumstances.

[0048] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to those processes, articles, or apparatus / devices.

[0049] The technical solution of this utility model has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the protection scope of this utility model is obviously not limited to these specific embodiments. Without departing from the principle of this utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this utility model.

Claims

1. A heat pump unit system for recovering thermal energy from produced water in oilfields, characterized in that: It includes a hot water tank (1) and a heat source water tank (2). The input end of the hot water tank (1) is connected to a conveying pipe (4) for conveying extracted water through an input pipe (3). The input end and output end of the heat source water tank (2) are also connected to the conveying pipe (4) through a heat source pipe (5) and an output pipe (6), respectively. Non-metallic collector one (11) and non-metallic collector two (21) are installed in the hot water tank (1) and the heat source water tank (2), respectively. It also includes a heat exchange unit (7). The non-metallic collector one (11) is connected to the condenser (71) in the heat exchange unit (7), and the non-metallic collector two (21) is connected to the evaporator (72) in the unit.

2. A heat pump unit system for recovering thermal energy from produced water in oilfields, characterized in that: It includes at least two hot water tanks (1) and a heat source water tank (2). The input ends of the multiple hot water tanks (1) are connected to a conveying pipe (4) for conveying the extracted water through an input pipe (3). The multiple hot water tanks (1) are connected in series. The input end and output end of the heat source water tank (2) are also connected to the conveying pipe (4) through a heat source pipe (5) and an output pipe (6), respectively. A non-metallic collector one (11) is installed in the hot water tank (1). A non-metallic collector two (21) is installed in the heat source water tank (2) for each hot water tank (1). A heat exchange unit (7) is also installed for each hot water tank (1). The non-metallic collector one (11) is connected to the condenser (71) in the heat exchange unit (7). The non-metallic collector two (21) is connected to the evaporator (72) in the heat exchange unit (7).

3. The oilfield produced water heat energy recovery heat pump unit system according to claim 1 or 2, characterized in that: The non-metallic collector one (11) is equipped with a hot water circulation pump (111), and the non-metallic collector two (21) is equipped with a heat source water circulation pump (211).

4. The oilfield produced water heat energy recovery heat pump unit system according to claim 1 or 2, characterized in that: A valve (31) is installed on the input pipe (3).

5. The oilfield produced water heat energy recovery heat pump unit system according to claim 1 or 2, characterized in that: The input pipe (3) is located upstream of the heat source pipe (5), and the output pipe (6) is located downstream of the heat source pipe (5).

6. The oilfield produced water heat energy recovery heat pump unit system according to claim 1 or 2, characterized in that: The non-metallic collector one (11) and the hot water tank (1) are configured as submersible, and the non-metallic collector two (21) and the heat source water tank (2) are also configured as submersible.

7. The oilfield produced water heat energy recovery heat pump unit system according to claim 2, characterized in that: A solenoid valve (8) is installed on the connecting pipe between two adjacent hot water tanks (1).

8. The oilfield produced water heat energy recovery heat pump unit system according to claim 2, characterized in that: Except for the first-stage hot water tank (1), all other hot water tanks (1) are connected to the input pipe (3) through a level valve (9).

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