Circulating water waste heat recovery device utilizing heat pump

Abstract

The utility model relates to the technical field of waste heat recovery, and discloses a circulating water waste heat recovery device utilizing a heat pump, which comprises a heat pump unit, the heat pump unit consists of a heat pump evaporator, a condenser, a compressor and a backflow expansion valve, the compressor is arranged behind the heat pump evaporator and the condenser, and the backflow expansion valve is arranged behind the heat pump evaporator and the condenser. An air inlet of the compressor is connected with an air outlet of the heat pump evaporator, an air outlet of the compressor is connected with an air inlet of the condenser, and a water conveying assembly is arranged at the front end of the heat pump evaporator. Through the water conveying assembly, the water conveying flow can be adjusted according to the temperature condition of circulating return water, so that the temperature of circulating water entering the heat pump evaporator is kept within a stable range, impurities in the circulating water can be screened out, the probability of blockage of all parts is reduced, and appropriate water treatment agents can be added into the heat source water conveying pipe regularly; and the scaling and corrosion probability of the water conveying component is further reduced.

Description

A waste heat recovery device for circulating water using a heat pump Technical Field

[0001] This utility model relates to the field of waste heat recovery technology, specifically a waste heat recovery device for circulating water using a heat pump. Background Technology

[0002] A heat pump unit is a device that operates on the principle of the reverse Carnot cycle. It uses a small amount of high-grade energy, such as electricity, to transfer heat from a low-temperature heat source, such as air, water, or soil, to a high-temperature heat source. However, the return water temperature of the circulating water is generally between 30-37℃, which is a low-grade heat source. The heat is dissipated into the atmosphere through a cooling tower, which is wasteful. A heat pump can be used to extract the heat from the return water and use it for process hot water, bathing hot water, or heating hot water to recover heat and reduce energy waste.

[0003] A search revealed a Chinese patent, CN116164445A, which discloses a device for recovering waste heat from circulating water using a heat pump. The device includes a generator, an absorber, an evaporator, and a condenser. The generator is connected to the condenser, and the absorber is connected to the evaporator. An evaporator heat transfer tube is installed inside the evaporator, and the circulating water, as the heat source water, enters the evaporator heat transfer tube from the heat source water inlet.

[0004] The above-mentioned device reduces the emission of waste heat from the power plant at the source by recovering the waste heat of the circulating water. It uses an absorption heat pump to preheat the demineralized water supplied by external steam, which significantly reduces operating costs compared to the traditional method of directly heating by extracting steam through a heat exchanger.

[0005] However, its liquid transport structure is relatively simple, directly transporting heat source water through circulating water pipes. It is difficult to adjust the flow rate of circulating water, and the temperature of the circulating water entering the heat exchanger is prone to change, which may affect the heat exchange efficiency. In addition, the circulating water may contain a small amount of impurities, scale or microorganisms, which can easily affect the heat exchange efficiency of the heat exchanger after long-term use. Summary of the Invention

[0006] The purpose of this invention is to provide a circulating water waste heat recovery device using a heat pump, which can effectively solve the problems in the background art.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A waste heat recovery device for circulating water using a heat pump includes a heat pump unit, which consists of a heat pump evaporator, a condenser, a compressor, and a reflux expansion valve. The compressor is installed behind the heat pump evaporator and the condenser, and the compressor's air inlet is connected to the heat pump evaporator's air outlet. The compressor's air outlet is connected to the condenser's air inlet. A water supply component is provided at the front end of the heat pump evaporator.

[0009] The water supply assembly includes a heat source water supply pipe, a filter pipe, a dosing pipe, and a flow control valve. The heat source water supply pipe, filter pipe, dosing pipe, and flow control valve are interconnected via sealing flanges. The end of the flow control valve furthest from the dosing pipe is connected to the inlet of the heat pump evaporator. A filter screen is installed inside the filter pipe. A sludge discharge pipe, compatible with the filter screen, is connected to the center of the bottom of the filter pipe. A backflushing pipe is installed at the center of the top of the dosing pipe, with one end of the backflushing pipe extending into the dosing pipe and reaching the interior of the filter screen. A medicine storage tank is installed at the center of the top of the dosing pipe, and a liquid filling pipe is connected to the bottom of the medicine storage tank, extending into the dosing pipe.

[0010] Preferably, the drain port of the condenser is connected to a circulation pipe, and the end of the circulation pipe away from the condenser is connected to the return port of the heat pump evaporator. A return expansion valve is provided at the connection between the circulation pipe and the condenser.

[0011] Preferably, a discharge solenoid valve is provided at the connection between the discharge pipe and the filter pipe, the filter screen cylinder is cylindrical, the backwash pipe is L-shaped, and the end of the backwash pipe that extends into the filter screen cylinder is provided with several flushing water holes.

[0012] Preferably, the heat pump evaporator is provided with a heat exchange tube inside, and a number of temperature sensors adapted to the flow control valve are provided through the outer ring of the heat exchange tube.

[0013] Preferably, the heat exchange tube is spirally arranged, and the end of the heat exchange tube away from the flow control valve is connected to a heat source outlet water pipe.

[0014] Preferably, an electrical control box is provided at the top of the heat pump evaporator, and the electrical control box is electrically connected to the heat pump evaporator, condenser, compressor, dosing solenoid valve, flow control valve, temperature sensor, and impurity discharge solenoid valve.

[0015] Preferably, a heating water inlet pipe is connected to the rear of the top of the condenser, and a heating water outlet pipe that is compatible with the heating water inlet pipe is provided at the center of the bottom of the condenser.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] This invention, by setting up a water supply component in conjunction with a heat pump evaporator, allows the flow rate of circulating water to be adjusted according to the temperature when the circulating water is delivered to the heat pump evaporator through a heat source water supply pipe. This is achieved by using a flow control valve and a temperature sensor, which keeps the temperature of the circulating water entering the heat pump evaporator within a relatively stable range, facilitating stable operation and reducing the impact on heat exchange.

[0018] By setting up filter pipes, filter screens, impurity discharge pipes, and backflush pipes in coordination, impurities in the circulating water can be screened out before it is transported, reducing the probability of blockage in various components. At the same time, it prevents impurities, scale, and microorganisms in the circulating water from affecting the heat exchange efficiency of the heat pump. Furthermore, by setting up chemical storage tanks, chemical dosing solenoid valves, and chemical dosing pipes in coordination, appropriate corrosion inhibitors, scale inhibitors, and other water treatment agents can be added to the heat source water supply pipes periodically, further reducing the probability of scaling and corrosion in the water supply components. Attached Figure Description

[0019] Figure 1 is a schematic diagram of the overall structure of a circulating water waste heat recovery device utilizing a heat pump in an embodiment of this utility model.

[0020] Figure 2 is an enlarged view of area A in Figure 1 in an embodiment of this utility model;

[0021] Figure 3 is a cross-sectional view of the internal structure of the filter tube and the dosing tube in the embodiment of this utility model;

[0022] Figure 4 is a top view of the structure of the heat pump evaporator, condenser and compressor in the embodiment of this utility model.

[0023] In the diagram: 1. Heat pump evaporator; 2. Condenser; 3. Compressor; 4. Circulation pipe; 5. Return expansion valve; 6. Water supply assembly; 7. Heat source water supply pipe; 8. Filter pipe; 9. Dosing pipe; 10. Flow control valve; 11. Filter screen cylinder; 12. Backflush pipe; 13. Impurity discharge pipe; 14. Chemical storage tank; 15. Dosing solenoid valve; 16. Heat source water outlet pipe; 17. Heated water inlet pipe; 18. Heated water outlet pipe. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0025] Example 1

[0026] Referring to Figures 1-4, a circulating water waste heat recovery device utilizing a heat pump includes a heat pump unit, which consists of a heat pump evaporator 1, a condenser 2, a compressor 3, and a reflux expansion valve 5. The compressor 3 is installed behind the heat pump evaporator 1 and the condenser 2, and the air inlet of the compressor 3 is connected to the air outlet of the heat pump evaporator 1, while the air outlet of the compressor 3 is connected to the air inlet of the condenser 2. A water supply assembly 6 is provided at the front end of the heat pump evaporator 1.

[0027] Referring to Figure 4, it is further seen that the water supply assembly 6 includes a heat source water supply pipe 7, a filter pipe 8, a dosing pipe 9, and a flow control valve 10. The heat source water supply pipe 7, filter pipe 8, dosing pipe 9, and flow control valve 10 are interconnected via sealing flanges. The end of the flow control valve 10 away from the dosing pipe 9 is connected to the inlet of the heat pump evaporator 1. The drain port of the condenser 2 is connected to a circulation pipe 4. The end of the circulation pipe 4 away from the condenser 2 is connected to the return port of the heat pump evaporator 1. A return expansion valve 5 is installed at the connection between the circulation pipe 4 and the condenser 2. A heat exchange tube is installed inside the heat pump evaporator 1, and the heat exchange tube passes through the heat exchange tube. The outer ring is equipped with several temperature sensors that are compatible with the flow control valve 10. The heat exchange tube is spirally arranged, and the end of the heat exchange tube away from the flow control valve 10 is connected to the heat source outlet water pipe 16. The top of the heat pump evaporator 1 is equipped with an electrical control box, which is electrically connected to the heat pump evaporator 1, condenser 2, compressor 3, dosing solenoid valve 15, flow control valve 10, temperature sensors, and impurity discharge solenoid valve. The top of the condenser 2 is connected to the heating water inlet pipe 17 at the rear position, and the bottom of the condenser 2 is equipped with a heating water outlet pipe 18 that is compatible with the heating water inlet pipe 17 at the center position.

[0028] Specifically, the heat pump unit consists of a heat pump evaporator 1, a condenser 2, a compressor 3, and a return expansion valve 5. Refrigerant can be delivered to the heat pump evaporator 1 as needed. Simultaneously, low-temperature circulating return water (30-37℃) is delivered to the heat pump evaporator 1 through the heat source water supply pipe 7. This allows the refrigerant in the heat pump evaporator 1 to absorb heat from the low-temperature heat source and evaporate, becoming a low-temperature, low-pressure gas. Subsequently, the compressor 3 can be started, compressing the low-temperature, low-pressure gas into a high-temperature, high-pressure gas, which is then transported... The hot water is sent to the condenser 2. During the transfer, the process hot water, bath hot water, or heating hot water to be heated can be sent to the condenser 2 through the heating water inlet pipe 17. At this time, the high-temperature and high-pressure gas input into the condenser 2 will transfer heat to the hot water to be heated. During the transfer, the temperature of the high-temperature gas drops and it will condense into liquid. Then, the condensed liquid flows through the circulation pipe 4 to the return expansion valve 5. The return expansion valve 5 plays a role in throttling and reducing pressure so that the condensate returns to the heat pump evaporator 1 to complete a cycle.

[0029] Example 2

[0030] Referring to Figures 2 and 3, and based on Embodiment 1, the following is further provided: a filter screen cylinder 11 is installed inside the filter tube 8; a discharge pipe 13, which is compatible with the filter screen cylinder 11, is connected to the center of the bottom end of the filter tube 8; a backflush pipe 12 is provided at the center of the top end of the dosing pipe 9, and one end of the backflush pipe 12 extends into the dosing pipe 9 and into the filter screen cylinder 11; a medicine storage tank 14 is installed at the center of the top end of the dosing pipe 9; a liquid addition pipe is connected to the bottom end of the medicine storage tank 14, and the liquid addition pipe extends into the dosing pipe 9; a discharge solenoid valve is provided at the connection between the discharge pipe 13 and the filter tube 8; the filter screen cylinder 11 is cylindrical; the backflush pipe 12 is L-shaped; and several flushing water holes are provided at the end of the backflush pipe 12 that extends into the filter screen cylinder 11.

[0031] Specifically, the heat source outlet pipe 16 allows the absorbed circulating water to be discharged. As the circulating water is transported through the heat source supply pipe 7, a temperature sensor, in conjunction with a flow control valve 10, monitors the water temperature in the supply pipe 7 in real time. The flow rate is automatically adjusted based on the temperature drop of the circulating water to maintain the temperature within a suitable range. Furthermore, a filter screen 11 filters impurities during the circulation process, preventing them from entering the heat pump evaporator 1. This reduces the probability of blockage in the water supply components and prevents impurities, scale, and microorganisms in the circulating water from affecting the heat exchange efficiency of the heat pump evaporator 1. The system has a high efficiency and can pre-connect the backwash pipe 12 to the external flushing water pipe and the discharge pipe 13 to the external sewage pipe. When the system is stopped, the discharge solenoid valve at the discharge pipe 13 can be opened, and the external flushing water flow can be delivered to the filter pipe 8 through the backwash pipe 12 to backwash and unblock the filter screen cylinder 11, reducing the probability of clogging of the filter screen cylinder 11. During use, appropriate corrosion inhibitors, scale inhibitors and other water treatment agents can be added to the chemical storage tank 14. When circulating the return water, the chemical dosing solenoid valve 15 can be opened to mix the water treatment agents into the filtered circulating return water, further reducing the probability of scaling and corrosion of the water supply components. The temperature sensor model is MIK-WZP.

[0032] In actual operation, the heat pump unit consists of a heat pump evaporator 1, a condenser 2, a compressor 3, and a return expansion valve 5. Refrigerant can be delivered to the heat pump evaporator 1 as needed. At the same time, low-temperature circulating return water at 30-37℃ is delivered to the heat pump evaporator 1 through the heat source water supply pipe 7. This allows the refrigerant delivered to the heat pump evaporator 1 to absorb heat from the low-temperature heat source and evaporate, becoming a low-temperature, low-pressure gas.

[0033] The compressor 3 can then be started. The compressor 3 can compress the low-temperature, low-pressure gas into a high-temperature, high-pressure gas. The high-temperature, high-pressure gas is then delivered to the condenser 2. During the delivery, the process hot water, bath hot water, or heating hot water to be heated can be delivered to the condenser 2 through the heating water inlet pipe 17. At this time, the high-temperature, high-pressure gas input into the condenser 2 will transfer heat to the hot water to be heated. During the transfer process, the temperature of the high-temperature gas drops and it will condense into liquid. The condensed liquid is then guided to the return expansion valve 5 through the circulation pipe 4. The return expansion valve 5 plays a role in throttling and reducing pressure so that the condensate can return to the heat pump evaporator 1 to complete a cycle. Before processing, the collection water pipe can be connected to the heating water outlet pipe 18 in advance so that the heated liquid can be exported for use.

[0034] The circulating return water with absorbed temperature can be exported through the heat source outlet pipe 16. When the circulating return water is transported through the heat source water supply pipe 7, the temperature of the water flow in the heat source water supply pipe 7 can be detected in real time by the set temperature sensor in conjunction with the flow control valve 10. Subsequently, by monitoring the temperature drop of the circulating return water, the flow rate is automatically adjusted to keep the temperature in a suitable range.

[0035] Furthermore, during the circulation return water transport, the filter screen 11 can filter out impurities in the process to prevent them from entering the heat pump evaporator 1, thereby reducing the probability of blockage of the water supply components and preventing impurities, scale and microorganisms in the circulating water from affecting the heat exchange efficiency of the heat pump evaporator 1.

[0036] Furthermore, the backwash pipe 12 can be pre-connected to the external flushing water pipe, and the waste discharge pipe 13 can be connected to the external sewage discharge pipe. When the machine is stopped, the waste discharge solenoid valve at the waste discharge pipe 13 can be opened, and the external flushing water flow can be delivered to the filter pipe 8 through the backwash pipe 12, so as to backwash and unblock the filter screen cylinder 11 and reduce the probability of the filter screen cylinder 11 being blocked.

[0037] During use, appropriate corrosion inhibitors, scale inhibitors and other water treatment agents can be added to the storage tank 14. When circulating the water back, the dosing solenoid valve 15 can be opened to mix the water treatment agents into the filtered circulating water, thereby further reducing the probability of scaling and corrosion of the water supply components.

[0038] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A waste heat recovery device for circulating water using a heat pump, comprising a heat pump unit, the heat pump unit consisting of a heat pump evaporator (1), a condenser (2), a compressor (3), and a reflux expansion valve (5), wherein the compressor (3) is installed behind the heat pump evaporator (1) and the condenser (2), and the air inlet of the compressor (3) is connected to the air outlet of the heat pump evaporator (1), and the air outlet of the compressor (3) is connected to the air inlet of the condenser (2), characterized in that: The heat pump evaporator (1) is provided with a water supply assembly (6) at its front end; the water supply assembly (6) has a heat source water supply pipe (7), a filter pipe (8), a dosing pipe (9), and a flow control valve (10). The heat source water supply pipe (7), the filter pipe (8), the dosing pipe (9), and the flow control valve (10) are connected to each other through a sealing flange. The end of the flow control valve (10) away from the dosing pipe (9) is connected to the water inlet of the heat pump evaporator (1). A filter screen is installed inside the filter pipe (8). The filter tube (8) is connected to a discharge pipe (13) at the center of the bottom end of the filter tube (8), which is compatible with the filter tube (11). A backflush pipe (12) is provided at the center of the top end of the dosing tube (9), and one end of the backflush pipe (12) extends into the dosing tube (9) and into the filter tube (11). A medicine storage tank (14) is installed at the center of the top end of the dosing tube (9), and a liquid filling pipe is connected to the bottom end of the medicine storage tank (14), which extends into the dosing tube (9).

2. The circulating water waste heat recovery device using a heat pump according to claim 1, characterized in that: The drain port of the condenser (2) is connected to a circulation pipe (4). The end of the circulation pipe (4) away from the condenser (2) is connected to the return port of the heat pump evaporator (1). A return expansion valve (5) is provided at the connection between the circulation pipe (4) and the condenser (2).

3. A waste heat recovery device for circulating water using a heat pump according to claim 1, characterized in that: A discharge solenoid valve is provided at the connection between the discharge pipe (13) and the filter pipe (8). The filter screen cylinder (11) is cylindrical, and the backwash pipe (12) is L-shaped. The end of the backwash pipe (12) that extends into the filter screen cylinder (11) is provided with several flushing water holes.

4. A waste heat recovery device for circulating water using a heat pump according to claim 3, characterized in that: The heat pump evaporator (1) is equipped with a heat exchange tube inside, and a number of temperature sensors adapted to the flow control valve (10) are arranged through the outer ring of the heat exchange tube.

5. A waste heat recovery device for circulating water using a heat pump according to claim 4, characterized in that: The heat exchange tube is spirally arranged, and the end of the heat exchange tube away from the flow control valve (10) is connected to the heat source outlet water pipe (16).

6. A waste heat recovery device for circulating water using a heat pump according to claim 5, characterized in that: An electrical control box is provided at the top of the heat pump evaporator (1), and the electrical control box is electrically connected to the heat pump evaporator (1), condenser (2), compressor (3), dosing solenoid valve (15), flow control valve (10), temperature sensor, and impurity discharge solenoid valve.

7. A waste heat recovery device for circulating water using a heat pump according to claim 1, characterized in that: The top of the condenser (2) is connected to a heating water inlet pipe (17) at the rear position, and the bottom of the condenser (2) is provided with a heating water outlet pipe (18) that is compatible with the heating water inlet pipe (17).

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