A waste heat recovery heating device with automatic switching mode

Abstract

The present invention relates to the field of waste heat recovery technology, and in particular to a waste heat recovery heating device with automatic switching mode, comprising a hot water tank, an electric valve and a connecting pipe; the hot water tank is provided with a first connecting pipe, a second connecting pipe and a third connecting pipe; the first connecting pipe is successively connected to the hot water tank through a first circulation pump and a first heat exchanger to form a loop; the second connecting pipe is divided into two branches after the No. 3 electric valve; the two branches are respectively a cooling tower branch and a water supply branch; the water supply branch includes a clean water branch and a heat pump branch; the cooling tower branch is connected to the cooling tower; the clean water branch is connected to a clean water interface; the heat pump branch is connected to a heat pump device; the third connecting pipe is divided into two paths after passing through a parallel valve group, one path is directly connected to the heat pump device, and the other path is connected to the cooling tower through the No. 6 electric valve. The present invention has diversified functions, can freely switch between multiple heating modes, can be used for multiple purposes, and reduces equipment costs.

Description

Technical Field

[0001] The invention relates to the technical field of waste heat recovery, and in particular to a waste heat recovery heating device with automatic mode switching. Background Art

[0002] Nowadays, automation equipment is widely used in production and life. Under the large-scale call for energy conservation and environmental protection, the recovery and utilization of waste heat generated by the equipment has attracted more and more attention and research. Bath centers need to prepare a large amount of hot and cold water for operation every day. Industrial equipment generates a large amount of waste heat that can be used for waste heat recovery. At present, there are the following waste heat recovery products on the market: non-waste heat recovery type water-heating device (including direct heating and circulating heating mode); direct heating type waste heat recovery water-heating device; circulating heating type waste heat recovery water-heating device; single heating waste heat recovery water-heating device + auxiliary refrigeration device. Among them, the non-waste heat recovery type water-heating device does not recover the heat energy in the bathing wastewater, causing a lot of energy waste, and can only be used as a supplementary or backup heat source; direct heating type and circulating heating type waste heat recovery water-heating device, although it recovers the heat energy in the bathing wastewater, has a single function and does not take into account the summer cooling demand, which increases the investment in refrigeration equipment and the system operation cost. The single waste heat recovery + auxiliary refrigeration device is a product with good economic applicability at present, but it cannot solve the contradiction between rapid hot water production, maintaining constant temperature of the water tank and long-term stable refrigeration, and the imbalance between cold and heat is prominent. The direct heating + auxiliary cooling device cannot cool when the hot water tank is full, and the liquid level must be lowered to start the cooling machine, which causes energy waste when the process does not require hot water. The circulating heat + auxiliary cooling device cannot meet the requirements of rapid hot water production, unless the heating capacity is increased and the investment is increased, but this may be much greater than the refrigeration load, resulting in increased energy consumption. Summary of the invention

[0003] The purpose of the present application is to provide a waste heat recovery heating device with automatic switching modes, aiming to solve the problems in the prior art.

[0004] The embodiment of the present application provides a waste heat recovery heating device with automatic switching mode, including a hot water tank, an electric valve and a connecting pipe; the hot water tank is provided with a first connecting pipe, a second connecting pipe and a third connecting pipe; the first connecting pipe is connected to the hot water tank through a first circulation pump and a first heat exchanger in turn to form a loop; the second connecting pipe is provided with a hot water circulation pump and a No. 3 electric valve; the second connecting pipe is divided into two branches after the No. 3 electric valve; the two branches are a cooling tower branch and a water supply branch; the water supply branch includes a fresh water branch and a heat pump branch; the cooling tower branch is provided with a cooling tower circulation pump and a No. 5 electric valve, and the cooling tower branch The clean water branch line is connected to the cooling tower; the clean water branch line is provided with a No. 1 electric valve and the first wastewater heat exchanger and is connected to the clean water interface; a clean water pressure gauge is provided between the clean water interface and the first wastewater heat exchanger; the heat pump branch line is connected to the heat pump device; the heat pump device is connected to the condensation pump, the second wastewater heat exchanger and the air-conditioning heat exchanger through a connecting pipe and is connected back to the heat pump device to form a loop; a parallel valve group is provided on the third connecting pipe; the parallel valve group is a No. 4 electric valve and a No. 2 electric valve arranged in parallel; the third connecting pipe is divided into two paths after passing through the parallel valve group, one path is directly connected to the heat pump device, and the other path is connected to the cooling tower through the No. 6 electric valve.

[0005] Furthermore, a hot water tank level changer and a temperature transmitter are provided in the hot water tank; an air conditioning return water temperature transmitter is provided between the air conditioning heat exchanger and the air conditioning equipment; the hot water tank level changer, temperature transmitter and air conditioning return water temperature transmitter are all electrically connected to the PLC controller.

[0006] Furthermore, the first heat exchanger is connected to an external constant temperature bath or floor heating pipeline via a circulation pump.

[0007] Furthermore, an overflow pipe is provided at the top of the hot water tank; and a sewage pipe is provided at the bottom of the hot water tank.

[0008] Furthermore, the first wastewater heat exchanger is connected to the wastewater tank via a wastewater connecting pipe; the wastewater connecting pipe is provided with a filter, a wastewater pump and a wastewater pressure gauge.

[0009] Furthermore, the hot fluid of the second wastewater heat exchanger is connected to that of the first wastewater heat exchanger through a connecting pipe; and the cold fluid of the second wastewater heat exchanger and the air-conditioning heat exchanger is connected through a connecting pipe.

[0010] Furthermore, the thermal fluid of the air-conditioning heat exchanger is high-temperature return water generated by the air-conditioning equipment, which flows into the air-conditioning heat exchanger through the air-conditioning pump and the connecting pipe.

[0011] The beneficial effects of the present invention are as follows: the present invention adopts cascade technology to fully recover the heat energy in the wastewater for hot water production, reduces power consumption, and reduces operating costs; adopts heat pump technology to achieve simultaneous heating and cooling, consumes a small amount of power to achieve multi-level utilization of energy, and reduces the investment and operating costs of refrigeration equipment. The direct heating and circulating heating automatic switching technology, according to the liquid level, temperature and air conditioning return water temperature control, takes advantage of several modes to solve the contradiction of rapid hot water production, water tank maintaining constant temperature and long-term stable cooling. When the hot water tank is full and the temperature reaches the upper limit, it can also automatically switch to the cooling tower for cooling, ensuring that summer refrigeration meets the cooling load of the air-conditioned room. Intelligent and remote control technology captures temperature and liquid level, intelligently switches the operating mode, and controls other logical functions and actions. 24-hour real-time monitoring and operation. Reduce manual intervention; compared with the existing waste heat recovery system, the present invention has strong economic applicability, diversified functions, can be used for multiple purposes, and reduces the initial investment and operating costs of equipment; the comprehensive energy-saving effect is more than 76% of the existing equipment, and the economic and social benefits are outstanding. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the waste heat recovery heating system device of the present invention.

[0013] Figure 2 The electrical schematic diagram of the control device of the present invention.

[0014] Figure 3 This is the electrical schematic diagram of the control system of the present invention.

[0015] In the figure:

[0016] 1. Hot water tank; 2. External constant temperature bath or floor heating pipe; 3. First heat exchanger; 4. Circulation pump; 5. First connecting pipe; 6. Hot water circulation pump; 7. Second connecting pipe; 8. No. 1 electric valve; 9. No. 2 electric valve; 10. No. 3 electric valve; 11. No. 4 electric valve; 12. No. 5 electric valve; 13. No. 6 electric valve; 14. Cooling tower; 15. Waste water tank; 16. Heat pump device; 17. Third connecting pipe; 18. Clean water branch line ; 19. Heat pump branch line; 21. First wastewater heat exchanger; 22. Second wastewater heat exchanger; 23. Air conditioning heat exchanger; 24. Air conditioning equipment; 25. Wastewater connecting pipe; 26. Wastewater pump; 27. Filter; 28. Wastewater pressure gauge; 29. ​​Clean water pressure gauge; 30. Condensate pump; 31. First circulation pump; 32. Overflow pipe; 33. Sewage pipe; 34. Cooling tower circulation pump; 35. Cooling tower branch line; 36. Air conditioning pump. DETAILED DESCRIPTION

[0017] 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 only 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.

[0018] like Figures 1 to 3 The waste heat recovery heating device with automatic switching mode shown in the figure comprises a hot water tank 1, an electric valve and a connecting pipe; the hot water tank 1 is provided with a first connecting pipe 5, a second connecting pipe 7 and a third connecting pipe 17; the first connecting pipe 5 is connected to the hot water tank 1 through the first circulating pump 31 and the first heat exchanger 3 in turn to form a closed loop; the second connecting pipe 7 is provided with a hot water circulating pump 6 and a No. 3 electric valve 10; the second connecting pipe 7 is divided into two branches after the No. 3 electric valve 10; the two branches are a cooling tower branch line 35 and a water supply branch line; the water supply branch line includes a clean water branch line 18 and a heat pump branch line 19; the cooling tower branch line 35 is provided with a cooling tower circulating pump 34 and a No. 5 electric valve 12, and the cooling tower branch line 35 is connected to the cooling tower 14; the clean water branch line 18 includes a clean water branch line 19 ... includes a cooling tower circulating pump 34 and a No. 5 electric valve 12, and the cooling tower branch line 35 is connected to the cooling tower 14; the clean water branch line 18 includes a clean water branch line 18 and a heat pump branch line 19; the cooling tower branch line 35 includes a cooling tower circulating pump 34 and a No. 5 electric valve 12, and the cooling tower branch line 35 is connected to the cooling tower 14; the clean water branch line 18 includes a clean water branch line 18 and a heat pump branch line 19; the cooling tower branch line 35 includes a cooling tower circulating A No. 1 electric valve 8 and a first wastewater heat exchanger 21 are provided on the water branch line 18 and are connected to the clean water interface; a clean water pressure gauge 29 is provided between the clean water interface and the first wastewater heat exchanger 21; the heat pump branch line 19 is connected to the heat pump device 16; the heat pump device 16 is connected to the condensation pump 30, the second wastewater heat exchanger 22 and the air-conditioning heat exchanger 23 through a connecting pipe and is connected back to the heat pump device 16 to form a loop, and the heat pump device 16 can specifically use a heat pump compressor; a parallel valve group is provided on the third connecting pipe 17; the parallel valve group is a No. 4 electric valve 11 and a No. 2 electric valve 9 arranged in parallel; the third connecting pipe 17 is divided into two paths after passing through the parallel valve group, one path is directly connected to the heat pump device 16, and the other path is connected to the cooling tower 14 through the No. 6 electric valve 13.

[0019] The hot water tank 1 is provided with a hot water tank level changer and a temperature transmitter; an air conditioning return water temperature transmitter is provided between the air conditioning heat exchanger 23 and the air conditioning equipment 24; the hot water tank level changer, the temperature transmitter and the air conditioning return water temperature transmitter are all electrically connected to the PLC controller; the system operation status is uploaded to the PLC controller through the analog signals of the hot water tank level changer, the temperature transmitter and the air conditioning return water temperature transmitter. The PLC can use S7-200 SMART SR60, and after intelligent judgment by the logic program, it issues an action command to the corresponding electric valve to complete the automatic switching of the heating mode, thereby meeting the requirements of long-term cooling in summer.

[0020] The first heat exchanger is connected to the external constant temperature bath or floor heating pipe 2 through a circulation pump 4 for heat exchange; multiple first heat exchangers 3 can be set, and the main function of the first heat exchanger 3 is to exchange the heat of the hot water in the hot water tank 1 with the water in the external constant temperature bath or floor heating pipe 2, thereby ensuring the water temperature in the bath and the floor heating and achieving the purpose of preparing hot water.

[0021] An overflow pipe 32 is provided at the top of the hot water tank 1 ; a sewage pipe 33 is provided at the bottom of the hot water tank 1 .

[0022] The first wastewater heat exchanger 21 is connected to the wastewater tank 15 through a wastewater connecting pipe 25; a filter 27, a wastewater pump 26 and a wastewater pressure gauge 28 are provided on the wastewater connecting pipe 25. The water in the wastewater tank 15 is 30-35°C bathing wastewater, and the filter 27 can be used in combination with a coarse-effect filter and a multifunctional intelligent control filter.

[0023] The second wastewater heat exchanger 22 is connected to the hot fluid of the first wastewater heat exchanger 21 through a connecting pipe; the second wastewater heat exchanger 22 is connected to the cold fluid of the air-conditioning heat exchanger 23 through a connecting pipe.

[0024] The thermal fluid of the air conditioning heat exchanger 23 is high-temperature return water generated by the air conditioning equipment 24 , which flows into the air conditioning heat exchanger 23 through the air conditioning pump 36 and the connecting pipe.

[0025] The cascade technology of the present invention is to repeatedly extract heat energy by superimposing the heat exchange of the heat exchanger and the heat pump compressor heat raising process, perform deep heat energy extraction on the bathing wastewater twice, transfer all the heat to the clean water, and achieve the dual purpose of waste heat recovery and hot water preparation. The heat exchange process of the clean water is as follows: the cold fluid in the first wastewater heat exchanger 21 is clean water, and the clean water first passes through the first wastewater heat exchanger 21 to heat exchange and heat up with 30-35℃ bathing wastewater. After the temperature is raised, the bathing wastewater at about 15℃ is fully extracted for the second time by the heat pump compressor, and the temperature is 3-5℃ when discharged. At the same time, the clean water at 15℃ is heated twice by heat exchange and heat pump work to reach 40-65℃ (adjustable) and stored in the hot water tank 1 for standby use. This process is a direct heating mode.

[0026] The working process of the whole system of the present invention can be divided into two seasons. In winter, the system working conditions are divided into two modes, with direct heating as the main mode and circulating heating as the auxiliary mode. The main process is as follows: when the liquid level of the hot water tank 1 is lower than the starting liquid level, the No. 1 electric valve 8 and the No. 2 electric valve 9 are opened, the clean water interface is opened, and the waste water pump 26 and the condensing pump 30 are opened for a delay of 10 seconds. When the clean water pressure gauge 29 and the waste water pressure gauge 28 reach high pressure, the waste heat recovery unit is turned on. At this time, the direct heating mode is used to make hot water. 15℃ clean water is directly heated to 40-60℃ and stored in the insulated hot water tank 1. When the water tank liquid level is higher than the stop liquid level and the temperature is higher than the set value for the shutdown of circulating heating, the unit is shut down.

[0027] (2) When the liquid level of hot water tank 1 is higher than the stop level and the temperature of hot water tank 1 is lower than the set circulation heating start setting value, the unit switches to circulation heating mode. At this time, electric valve No. 1 8 and electric valve No. 2 9 are closed, electric valve No. 3 10 and electric valve No. 4 11 are opened, condensing pump 30 is closed after a delay of 5 seconds, hot water circulation pump 6 is turned on, and other equipment of the unit remains unchanged. When the water tank liquid level is higher than the stop level and the temperature is higher than the circulation heating shutdown setting value, the unit shuts down. (Does not occur often)

[0028] In summer, the system operating conditions can be divided into four modes:

[0029] (1) When the return water temperature of the air conditioner is greater than the set value of 15°C and the liquid level in the hot water tank 1 is lower than the starting liquid level, the No. 1 electric valve 8 and the No. 2 electric valve 9 are opened, the clean water interface is opened, the waste water pump 26 and the condensing pump 30 are turned on, and the delay is 10 seconds. When the clean water pressure gauge 29 and the waste water pressure gauge 28 reach high pressure, the waste heat recovery unit is turned on and the system is in direct heating mode;

[0030] (2) When the liquid level of hot water tank 1 is higher than the stop level and the return water temperature of the air conditioner has not reached the shutdown temperature, and the temperature of hot water tank 1 is lower than the set circulation heating start setting value, the system switches to circulation heating mode. At this time, the No. 1 electric valve 8 and the No. 2 electric valve 9 are closed, the No. 3 electric valve 10 and the No. 4 electric valve 11 are opened, the hot water circulation pump 6 is turned on, and the condensing pump 30 is turned off after a delay of 5 seconds. Other equipment of the unit remains unchanged.

[0031] (3) When the liquid level in the hot water tank 1 reaches the shutdown liquid and the temperature is higher than the shutdown setting value of the circulating heating, and the return water temperature of the air conditioner has not reached the shutdown temperature, the system switches to the cooling tower circulation heat exchange mode. At this time, the No. 3 electric valve 10 and the No. 4 electric valve 11 are closed, the No. 5 electric valve 12 and the No. 6 electric valve 13 are opened, the cooling tower circulation pump 34 and the fan are turned on, and the hot water circulation pump 6 is turned off after a delay of 5 seconds. Other equipment of the unit remains unchanged.

[0032] (4) When the air conditioning return water temperature reaches the shutdown temperature, the system stops running.

[0033] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A waste heat recovery heating device with automatic switching mode, characterized in that: It comprises a hot water tank, an electric valve and a connecting pipe; the hot water tank is provided with a first connecting pipe, a second connecting pipe and a third connecting pipe; the first connecting pipe is connected to the hot water tank through a first circulation pump and a first heat exchanger in turn and finally forms a loop; the second connecting pipe is provided with a hot water circulation pump and a No. 3 electric valve; the second connecting pipe is divided into two branches after the No. 3 electric valve; the two branches are a cooling tower branch and a water supply branch respectively; the water supply branch comprises a clean water branch and a heat pump branch; a cooling tower circulation pump and a No. 5 electric valve are provided on the cooling tower branch, and the cooling tower branch is connected to the cooling tower; a No. 1 electric valve and a first wastewater heat exchanger are provided on the clean water branch and are connected to the clean water interface; a clean water pressure gauge is provided between the clean water interface and the first wastewater heat exchanger; the heat pump branch is connected to the heat pump device; the heat pump device passes through The connecting pipe is connected to the condensing pump, the second wastewater heat exchanger and the air-conditioning heat exchanger and is connected back to the heat pump device to form a loop; the second wastewater heat exchanger is connected to the hot fluid of the first wastewater heat exchanger through a connecting pipe; a parallel valve group is provided on the third connecting pipe; the parallel valve group is a No. 4 electric valve and a No. 2 electric valve arranged in parallel; the cold fluid of the second wastewater heat exchanger and the air-conditioning heat exchanger is connected through a connecting pipe; the third connecting pipe is divided into two paths after passing through the parallel valve group, one path is directly connected to the heat pump device, and the other path is connected to the cooling tower through the No. 6 electric valve; a hot water tank level transmitter and a temperature transmitter are provided in the hot water tank; an air-conditioning return water temperature transmitter is provided between the air-conditioning heat exchanger and the air-conditioning equipment; the hot water tank level transmitter, temperature transmitter and air-conditioning return water temperature transmitter are all electrically connected to the PLC controller.

2. The waste heat recovery heating device with automatic switching mode according to claim 1, characterized in that: The first heat exchanger is connected to an external constant temperature bath or floor heating pipeline through a circulation pump.

3. The waste heat recovery heating device with automatic switching mode according to claim 1, characterized in that: An overflow pipe is arranged on the top of the hot water tank; and a sewage pipe is arranged on the bottom of the hot water tank.

4. The waste heat recovery heating device with automatic switching mode according to claim 1, characterized in that: The first wastewater heat exchanger is connected to the wastewater tank through a wastewater connecting pipe; a filter, a wastewater pump and a wastewater pressure gauge are arranged on the wastewater connecting pipe.

5. The waste heat recovery heating device with automatic switching mode according to claim 1, characterized in that: The thermal fluid of the air-conditioning heat exchanger is high-temperature return water generated by the air-conditioning equipment, which flows into the air-conditioning heat exchanger through the air-conditioning pump and the connecting pipe.

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