CN202048721U - Heating device utilizing low grade heat source - Google Patents

Abstract

The utility model discloses a heating device utilizing a low-grade heat source, which comprises a heat source collector, a gas storage device, a vortex tube, a first heat exchanger, a second heat exchanger, a condenser, and a solution pump; The gas outlet of the heat source collector is connected to the gas inlet of the gas storage, the top gas outlet of the gas storage is connected to the inlet of the vortex tube, and the bottom liquid outlet of the gas storage is connected to the gas storage. The liquid recovery port of the heat source collector is connected, the hot end outlet of the vortex tube is connected with the first inlet of the first heat exchanger, the cold end outlet of the vortex tube is connected with the first The first outlets of the heat exchanger are respectively connected to the first inlets of the second heat exchanger. The heating device of the utility model has excellent improvements in the utilization of low-grade heat sources and energy saving. Not only that, the device also has the advantages of simple structure, reliable operation, strong continuity and wide adaptability.

Description

A heating device using a low-grade heat source

technical field

The utility model relates to an energy utilization device, in particular to a heating device utilizing a low-grade heat source.

Background technique

Energy is the material basis of social life and the material resource in nature that provides power for people's daily life. Fossil energy sources such as coal, oil, and natural gas provide sources of production materials and production power for industries such as steel, textiles, chemicals, and medical care. Energy is the lifeblood of the national economy and plays an important role in promoting the country's industrial development. However, the world's energy supply is increasingly tense, and countries have introduced new strategies to deal with the reduction of energy. A large amount of heat is released during the combustion of fossil energy such as coal, oil, and natural gas. Taking advantage of this feature, many large-scale power stations, steel plants and other large-scale equipment have been built, and the heat released by these combustions will be higher. The proportion of underutilized high-grade heat energy is reused in waste heat boilers and other equipment to improve utilization efficiency. While the number of times of utilization of these heat energy is increasing, its grade is gradually decreasing, thus becoming a low-grade energy source. Low-grade energy is difficult to recycle due to its low grade, limiting its use in various industries. For example, in the lithium bromide absorption refrigeration system, due to the influence of the physical properties of the lithium bromide solution itself, when the refrigerant water at a lower temperature is produced at a temperature of 80°C, the refrigeration coefficient is small, and with the decrease of the temperature, the refrigeration coefficient Decreased significantly.

Low-grade energy is at the lower level of the entire energy grade, and its total amount is relatively large, but because of its low reusability, it is often discharged into the atmosphere as waste heat, resulting in waste of low-grade energy, which is not conducive to energy cascade utilization carried out. At present, in order to recover these low-grade heat, people have made a lot of efforts. For example, the Chinese Utility Model Patent No. ZL 200520051879.9 discloses a device for producing hot water by using waste heat from central air conditioning.

For the system using the vortex tube, in the prior art, a compressor is basically provided before the vortex tube, and the gas is brought to a high-pressure state by using the compressor. For example, Chinese Patent Application No. 200710018736.1, "A High-Temperature Heat Pump System with a Vortex Tube" discloses a high-temperature heat pump system with a compressor and a vortex tube connected to the exhaust pipe of the compressor. The tube raises the temperature of the air flow, and after reheating of the water, a higher temperature can be reached. However, the system uses a compressor to change the low-temperature and low-pressure refrigerant into a high-temperature and high-pressure gas, which consumes a large amount of electric energy to drive the system while being pressurized and heated.

Utility model content

The utility model provides a heating device using a low-grade heat source. The device not only reuses the low-grade heat source, but also saves a compressor to achieve the effect of energy saving.

A heating device utilizing a low-grade heat source, comprising a heat source collector, a gas storage, a vortex tube, a first heat exchanger, a second heat exchanger, a condenser, and a solution pump; the gas outlet of the heat source collector and the The gas inlet of the gas storage is connected, the top gas outlet of the gas storage is connected with the inlet of the vortex tube, the bottom liquid outlet of the gas storage is connected with the liquid of the heat source collector The recovery port is connected, the outlet of the hot end of the vortex tube is connected with the first inlet of the first heat exchanger, the outlet of the cold end of the vortex tube is connected with the first outlet of the first heat exchanger respectively connected to the first inlet of the second heat exchanger, the first outlet of the second heat exchanger is connected to the inlet of the condenser, and the outlet of the condenser is connected to the solution The inlet of the pump is connected, the outlet of the solution pump is connected with the second inlet of the second heat exchanger, and the second outlet of the second heat exchanger is connected with the bottom inlet of the heat source collector .

Preferably, a third heat exchanger for high-temperature heat exchange is provided between the first heat exchanger and the second heat exchanger, and the first inlet of the third heat exchanger is connected to the The first outlet of the first heat exchanger is connected, the first outlet of the third heat exchanger is connected with the first inlet of the second heat exchanger, and the second The inlet is connected with the second outlet of the second heat exchanger, and the second outlet of the third heat exchanger is connected with the bottom inlet of the heat source collector. The addition of the third heat exchanger can reduce the heat load of the condenser.

The heat source collector is used to heat the fluid working medium to a high-pressure gas state.

The fluid working medium filled in the heating device can produce gas-liquid phase transition within the working temperature range, and is preferably water, ammonia, halogenated hydrocarbons or alcohols.

The low-grade heat source is generally a heat source below 300°C, preferably a heat source of 50-200°C.

The gas storage device can be used for stabilizing gas pressure and performing gas-liquid separation.

Preferably, the heating device is connected with the device requiring heat to form an integrated structure, which is easy to operate and has little heat loss.

Preferably, the device requiring heat is a hot water heat pump system, and the utility model is used to directly heat the circulating water of the heat pump, which can improve the utilization rate of heat energy and reduce the waste of heat energy.

Preferably, the device requiring heat is a single-effect lithium bromide absorption refrigeration system, which can directly obtain heat from the fluid working medium of the utility model after the system is connected with the device of the utility model into an integrated structure, so that the system can realize refrigeration , conducive to energy saving.

Therefore, the heating device utilizing the low-grade heat source of the present invention can realize the reutilization of the low-grade heat source, so it is of great significance to the cascade utilization of energy. In addition, the utility model uses a heat source collector to heat the heat transfer fluid working medium. Compared with the compressor system, it has the obvious advantage of directly utilizing low-grade heat sources such as boiler waste heat and cooling waste heat, and saving electric energy. In practical application, the high-temperature gaseous fluid working fluid produced by the heating device of the utility model can not only be used as heat source gas in the generator of the absorption refrigeration system, but also be used in heat pumps, small boilers and other occasions. In addition, the utility model can be integrated with some heat-requiring devices, such as heat pumps and absorption refrigeration systems, so as to facilitate heat transmission and reduce heat energy loss. Therefore, the heating device of the utility model has excellent improvements in the utilization of low-grade heat sources and energy saving. Not only that, the device also has the advantages of simple structure, reliable operation, strong continuity and wide application range.

Description of drawings

Fig. 1 is a schematic flow sheet of an embodiment of the present utility model;

Fig. 2 is a schematic flow diagram of the device of the present invention being used in a hot water heat pump system;

Fig. 3 is a schematic flow chart of the device of the present invention used in a single-effect lithium bromide absorption refrigeration system.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in further detail.

Example 1

Referring to Fig. 1, Fig. 1 is a schematic flow chart of an embodiment of the present utility model. The heating device includes a heat source collector 1, a gas storage 2, a vortex tube 3, a first heat exchanger 4, a condenser 5, a solution pump 6, and a second heat exchanger 7; the gas outlet of the heat source collector 1 and the The gas inlet of the gas storage 2 is connected, the gas outlet at the top of the gas storage 2 is connected with the inlet of the vortex tube 3, the liquid outlet at the bottom of the gas storage 2 is connected with the liquid recovery port of the heat source collector 1, and the hot end of the vortex tube 3 The outlet is connected to the first inlet of the first heat exchanger 4, the outlet of the cold end of the vortex tube 3 and the first outlet of the first heat exchanger 4 are respectively connected to the first inlet of the second heat exchanger 7, and the second heat exchanger The first outlet of the device 7 is connected with the inlet of the condenser 5, the outlet of the condenser 5 is connected with the inlet of the solution pump 6, the outlet of the solution pump 6 is connected with the second inlet of the second heat exchanger 7, and the second heat exchanger The second outlet of 7 is connected with the bottom inlet of heat source collector 1 .

In this embodiment, R245ca is used as the working fluid, and the low-grade heat source is low-grade cooling waste heat at 50-60°C generated by cooling towers in chemical plants. The liquid R245ca fluid working medium is heated by the heat source collector 1 to reach a high-pressure gas state at 45-55° C., and then enters the gas storage 2 . The R245ca liquid fluid working medium condensed due to heat leakage in the pipeline and the gas storage 2 is separated from the gaseous working fluid in the gas storage 2 in the gas storage 2, and the gas storage 2 has the function of stabilizing the gas pressure . The liquid separated from gas and liquid flows from the liquid outlet at the bottom of the gas storage 2 to the liquid recovery port of the heat source collector 1 , and flows back into the heat source collector 1 . The fluid working medium after the pressure stabilization of the gas storage 2 flows out from the top gas outlet of the gas storage 2, and enters the vortex tube 3 in a high-pressure state, and the high-temperature and low-pressure gaseous fluid working medium flows out from the hot end outlet of the vortex tube 3. After the high-temperature and low-pressure gaseous fluid working medium exchanges heat with the low-temperature fluid working medium in the first heat exchanger 4 and releases a large amount of heat, it mixes with the low-temperature and low-pressure fluid working medium flowing out from the outlet of the cold end of the vortex tube 3 and enters the second heat exchange unit. Heat exchange is carried out in the device 7, and then condensed into a liquid state by the condenser 5 and then pressurized by the solution pump 6, and the pressurized high-pressure liquid flows through the second heat exchanger 7 and then enters the heat source collector 1 to complete the cycle. In this embodiment, the low-temperature fluid working medium passes through the first heat exchanger 4 , and the high-temperature and low-pressure gaseous fluid working medium coming out of the hot end of the vortex tube 3 heats the low-temperature fluid working medium in the first heat exchanger 4 .

Table 1 is obtained by performing simulation calculation on this embodiment.

Table 1 The temperature reached by the device under different low-grade heat source temperatures and temperature rise conditions

Among them, the volume flow rate of R245ca entering the vortex tube is 2000Nm ³ /h, and the condensation temperature is 25°C. From Table 1, the temperature that the device can reach and the heat that can be generated under different low-grade heat source temperature conditions can be obtained. Through this embodiment, the reuse of the heat source at 50-60° C. can be realized. Moreover, the whole process is reliable in operation, strong in continuity and good in waste heat recovery effect.

Example 2

There is 60-70 ℃ waste heat in large chemical equipment, which needs to be cooled by the circulating water in the cooling tower. After the circulating water flows back into the cooling tower, the heat is discharged into the atmosphere. The utility model can utilize the low-grade waste heat of 60-70° C. In this embodiment, the 60-70° C. hot water is the low-grade heat source to be collected by the utility model device.

In addition, the heat pump is a device that transfers heat by compensating for the consumption of some low-grade heat sources. Traditional heat pumps use natural resources, such as the energy stored in outdoor air, soil, ocean, etc., but often due to the low energy of these substances, the temperature that the heat pump can reach is not very high. The first heat exchanger of the utility model and the heat pump system are connected into an integrated structure, so that the heat pump can obtain higher temperature circulating water to supply users, and realize the reuse of the above-mentioned low-grade heat source.

Referring to Fig. 2, Fig. 2 is a schematic flow diagram of the device of the present invention used in a hot water heat pump system. The heating device includes a heat source collector 1, a gas storage 2, a vortex tube 3, a first heat exchanger 4, a condenser 5, a solution pump 6, a second heat exchanger 7, and a third heat exchanger 8; The gas outlet of collector 1 is connected to the gas inlet of gas storage 2, the top gas outlet of gas storage 2 is connected to the inlet of vortex tube 3, the bottom liquid outlet of gas storage 2 is connected to the liquid recovery port of heat source collector 1 , the outlet of the hot end of the vortex tube 3 is connected to the first inlet of the first heat exchanger 4, the first outlet of the first heat exchanger 4 is connected to the first inlet of the third heat exchanger 8, and the cold end of the vortex tube 3 The outlet and the first outlet of the third heat exchanger 8 are respectively connected to the first inlet of the second heat exchanger 7, the first outlet of the second heat exchanger 7 is connected to the inlet of the condenser 5, and the outlet of the condenser 5 is connected to the inlet of the condenser 5. The inlet of the solution pump 6 is connected, the outlet of the solution pump 6 is connected with the second inlet of the second heat exchanger 7, the second outlet of the second heat exchanger 7 is connected with the second inlet of the third heat exchanger 8, and the third The second outlet of the heat exchanger 8 is connected with the bottom inlet of the heat source collector 1 .

In this embodiment, the fluid working medium is R245ca, the second heat exchanger is a low-temperature heat exchanger, the third heat exchanger is a high-temperature heat exchanger, and the low-grade heat source is the above-mentioned 60-70°C heat source. A heat exchanger 4 is connected to the heat pump system, and the circulating water of the heat pump passes through the first heat exchanger 4 . The R245ca liquid fluid working medium is heated by the heat source collector 1 to reach a high-pressure gas state at 55-65° C., and then enters the gas storage 2 . The R245ca liquid fluid working medium condensed due to heat leakage in the pipeline and the gas storage 2 is separated from the gaseous working fluid in the gas storage 2 in the gas storage 2, and the gas storage 2 has the function of stabilizing the gas pressure . The liquid separated from gas and liquid flows from the liquid outlet at the bottom of the gas storage 2 to the liquid recovery port of the heat source collector 1 , and flows back into the heat source collector 1 . The fluid working medium after the pressure stabilization of the gas storage 2 flows out from the top gas outlet of the gas storage 2, and enters the vortex tube 3 in a high-pressure state, and the high-temperature and low-pressure gaseous fluid working medium flows out from the hot end outlet of the vortex tube 3. After the high-temperature and low-pressure gaseous fluid working medium exchanges heat with the heat pump circulating water in the first heat exchanger 4 and releases a large amount of heat, it enters the third heat exchanger 8 and exchanges heat with the second heat exchanger 7. The liquid is heat-exchanged, and then mixed with the low-temperature and low-pressure fluid working medium flowing out of the cold end outlet of the vortex tube 3, enters the second heat exchanger 7 for heat exchange, and then is condensed into a liquid state by the condenser 5 and then pressurized by the solution pump 6 , the pressurized high-pressure liquid flows through the second heat exchanger 7 and the third heat exchanger 8 in sequence, and then enters the heat source collector 1 to complete the cycle. Since the temperature of the fluid working medium R245ca is higher after being heated at the heat source temperature, a third heat exchanger is added in this embodiment. The third heat exchanger provided in this embodiment can reduce the heat load of the condenser and improve the return The temperature of the fluid working medium flowing into the heat source collector improves the waste heat recovery rate of the system.

Table 2 can be obtained by performing simulation calculation on this embodiment.

Table 2 The heat generated under different low-grade heat source temperature and temperature rise conditions and the temperature reached by the heat pump circulating water

Among them, the volume flow rate of R245ca is 1500Nm ³ /h, and the condensation temperature is 32°C. It can be seen from Table 2 that the higher the temperature reached by the heat pump circulating water, the less heat it can obtain, which is mainly due to the decrease of heat flow as the temperature increases. In the first heat exchanger 4, the low-temperature heat pump circulating water is heated to about 80-95°C, and then the heated hot water is supplied to the user, thereby realizing the use of the heat source of 60-70°C to heat the heat pump circulating water to purpose of higher temperature. In addition, because this embodiment utilizes the waste heat of about 60-70° C., the heat load of the cooling tower can be reduced.

Example 3

Due to the physical properties of the lithium bromide solution in the lithium bromide absorption refrigeration system, the efficiency is relatively low when the refrigerant water at a lower temperature is produced at a temperature of 80°C or below. There is unutilized waste heat of 65-80°C in the boiler. In this embodiment, the utility model is connected with the lithium bromide refrigeration system into an integrated structure, and the above-mentioned 65-80°C waste heat is used as the low-grade heat source to be collected by the heat source collector.

Referring to Fig. 3, Fig. 3 is a schematic flow diagram of the utility model device used in a single-effect lithium bromide absorption refrigeration system. The heating device includes a heat source collector 1, a gas storage 2, a vortex tube 3, a first heat exchanger 4, a first condenser 15, a first solution pump 16, a second heat exchanger 7, and a third heat exchanger 8, the second condenser 9, the evaporator 10, the second solution pump 11, the absorber 12, the third solution pump 13, the fourth heat exchanger 14; the gas outlet of the heat source collector 1 and the gas of the gas storage 2 The inlet is connected, the top gas outlet of the gas storage 2 is connected to the inlet of the vortex tube 3, the bottom liquid outlet of the gas storage 2 is connected to the liquid recovery port of the heat source collector 1, and the hot end outlet of the vortex tube 3 is connected to the first heat exchange tube The first inlet of the heat exchanger 4 is connected, the first outlet of the first heat exchanger 4 is connected with the first inlet of the third heat exchanger 8, and the cold end outlet of the vortex tube 3 is connected with the first outlet of the third heat exchanger 8 respectively. Connected to the first inlet of the second heat exchanger 7, the first outlet of the second heat exchanger 7 is connected to the inlet of the first condenser 15, and the outlet of the first condenser 15 is connected to the inlet of the first solution pump 16, The outlet of the first solution pump 16 links to each other with the second inlet of the second heat exchanger 7, and the second outlet of the second heat exchanger 7 links to each other with the second inlet of the third heat exchanger 8, and the second inlet of the third heat exchanger 8 links to each other. The second outlet is connected to the bottom inlet of the heat source collector 1, and the second outlet of the first heat exchanger 4 is successively communicated with the second condenser 9, the evaporator 10, the absorber 12, and the third solution pump 13 (the second condensation The outlet of the device 9 is connected with the first inlet of the evaporator 10, the first outlet of the evaporator 10 is connected with the first inlet of the absorber 12), the outlet of the third solution pump 13 is connected with the first inlet of the fourth heat exchanger 14 connected, the first outlet of the fourth heat exchanger 14 is connected with the second inlet of the first heat exchanger 4, the third outlet of the first heat exchanger 4 is connected with the second inlet of the fourth heat exchanger 14, and the fourth The second outlet of the heat exchanger 14 is connected with the second inlet of the absorber 12, the second outlet of the evaporator 10 is connected with the inlet of the second solution pump 11, and the outlet of the second solution pump 11 is connected with the second inlet of the evaporator 10. connected.

In this embodiment, the first heat exchanger is a single-effect lithium bromide absorption refrigeration system generator, the second heat exchanger is a low-temperature heat exchanger, the third heat exchanger is a high-temperature heat exchanger, and the low-grade heat source is produced by a boiler. The waste heat of 65-80 ℃, the fluid working medium is R245ca. The fluid working medium R245ca with a volume flow rate of 1000NM ³ /h is passed into the heat source collector 1, and R245ca enters the gas storage 2 after being heated by the heat source collector 1 and reaches a high pressure state at a temperature of 60-75°C. The R245ca liquid fluid working medium condensed due to heat leakage in the pipeline and the gas storage 2 is separated from the gaseous working fluid in the gas storage 2 in the gas storage 2, and the gas storage 2 has the function of stabilizing the gas pressure . The liquid separated from gas and liquid flows from the liquid outlet at the bottom of the gas storage 2 to the liquid recovery port of the heat source collector 1 , and flows back into the heat source collector 1 . The fluid working medium after being stabilized by the gas storage 2 flows out from the top gas outlet of the gas storage 2, and enters the vortex tube 3 in a high-pressure state, and the hot end outlet of the vortex tube 3 flows out a high-temperature and low-pressure fluid with a temperature of about 100-120°C Working medium, then the high-temperature and low-pressure fluid working medium flows into the first heat exchanger 4 to release a large amount of heat, then enters the third heat exchanger 8 to exchange heat with the liquid returning from the second heat exchanger 7, and then exchanges heat with the liquid from the vortex tube 3 The low-temperature and low-pressure fluid working medium flowing out of the outlet of the cold end is mixed, enters the second heat exchanger 7 to release heat, and is condensed into a liquid state by the first condenser 15. After being pressurized by the first solution pump 16, the high-pressure liquid flows through the second heat exchanger in turn. The heat exchanger 7 and the third heat exchanger 8 enter the heat source collector 1 to complete the cycle. The first heat exchanger 4 obtains a large amount of heat from the high-temperature R245ca coming out of the hot end of the vortex tube, which is used for the refrigeration system to realize refrigeration. Since the temperature of the fluid working medium R245ca is higher after being heated at the heat source temperature, a third heat exchanger is added in this embodiment. The third heat exchanger provided in this embodiment can reduce the heat load of the condenser and improve the return The temperature of the fluid working medium flowing into the heat source collector improves the waste heat recovery rate of the system.

The following table 3 can be obtained by performing simulation calculation on this embodiment.

Table 3 Refrigeration capacity obtained under different low-grade heat source temperature and temperature rise conditions

Wherein, the condensation temperature in the second condenser 7 is 32°C, the condensation temperature in the first condenser 15 is 35°C, the outlet temperature of the refrigerant water in the evaporator 10 is 7°C, and the volume flow rate of R245ca is 1000NM ³ /h. It can be seen from Table 3 that the waste heat of 65-80°C can be heated by the device to reach about 100-120°C to drive the lithium bromide refrigerator for refrigeration. It can also be concluded from Table 3 that under this set condition, when the temperature of the heat source is heated to 110°C, the lithium bromide absorption refrigeration system can obtain the maximum cooling capacity, thereby maximizing the utilization of the low-grade heat source.

To sum up, using the waste heat generated by the boiler at about 65-80°C to heat the fluid working medium through the device of this embodiment, the temperature can reach 100-120°C, and then supply it to the absorption refrigeration system, thereby making lithium bromide refrigerate The system can utilize this 65-80°C heat source.

Claims (4)

1. A heating device utilizing a low-grade heat source, characterized in that: the device comprises a heat source collector, a gas storage device, a vortex tube, a first heat exchanger, a second heat exchanger, a condenser, and a solution pump; The gas outlet of the heat source collector is connected to the gas inlet of the gas storage, the top gas outlet of the gas storage is connected to the inlet of the vortex tube, and the bottom liquid outlet of the gas storage is connected to the The liquid recovery port of the heat source collector is connected, the outlet of the hot end of the vortex tube is connected with the first inlet of the first heat exchanger, and the outlet of the cold end of the vortex tube is connected with the first inlet of the first heat exchanger. The first outlet of a heat exchanger is respectively connected to the first inlet of the second heat exchanger, the first outlet of the second heat exchanger is connected to the inlet of the condenser, and the condenser The outlet of the device is connected with the inlet of the solution pump, the outlet of the solution pump is connected with the second inlet of the second heat exchanger, and the second outlet of the second heat exchanger is connected with the The bottom inlet of the heat source collector is connected. 2. The heating device utilizing a low-grade heat source according to claim 1, characterized in that: a third heat exchanger is arranged between the first heat exchanger and the second heat exchanger, and the The first inlet of the third heat exchanger is connected to the first outlet of the first heat exchanger, and the first outlet of the third heat exchanger is connected to the first inlet of the second heat exchanger , the second inlet of the third heat exchanger is connected with the second outlet of the second heat exchanger, the second outlet of the third heat exchanger is connected with the bottom inlet of the heat source collector connected. 3. The heating device utilizing a low-grade heat source according to claim 1, wherein the heating device is connected with a hot water heat pump system to form an integrated structure. 4. The heating device using a low-grade heat source according to claim 1, characterized in that: the heating device is connected with a single-effect lithium bromide absorption refrigeration system to form an integrated structure.

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