CN211782094U - Directly-heated efficient air source heat pump system for energy gradient utilization - Google Patents

Abstract

A direct-heating high-efficiency air source heat pump system for energy cascade utilization, the system includes a heat pump cycle, a water cycle and a sanitary hot water cycle. The utility model can not only ensure indoor heating, but also can conveniently prepare sanitary hot water, so as to ensure the stable and efficient operation of the system throughout the year. The first air-cooler heating constant temperature water tank realizes heating through the multi-stage heating terminal, and the low-temperature heating terminal and the high-temperature heating terminal are connected in series at the outlet of the water tank, and are controlled by four stop valves to realize the cascade utilization of energy. Satisfying the comfort requirements of the residents without causing too much waste can be said to kill two birds with one stone. At the same time, the utility model controls the second air cooler to heat the sanitary hot water through three cut-off valves, so as to meet the water demand of the households. The utility model provides a direct-heating high-efficiency air source heat pump system which can effectively improve the energy efficiency of the system and utilize the energy cascade with higher efficiency.

Description

Direct heating high-efficiency air source heat pump system for energy cascade utilization

technical field

The utility model belongs to the field of heat pumps and relates to a direct heat type heat pump.

Background technique

A heat pump is a device that uses a small amount of driving energy to convert a large amount of low-temperature energy into high-temperature energy. According to the heat source medium, it can be divided into air energy heat pump, water source heat pump and ground source heat pump. Existing air-energy heat pumps can be divided into two types: circulation type and direct heat type. The direct heating unit keeps the inlet water temperature constant, high heat exchange efficiency, strong heat absorption capacity, stable condensing temperature, exhaust temperature, exhaust pressure and operating current, which greatly prolongs the operating life of the compressor. Heat pumps have been paid more and more attention in practical engineering.

In northern my country, the temperature in winter is often very low, and some rural areas often use coal-fired boilers for heating. In recent years, environmental and energy issues have attracted more and more attention, and the country has paid more and more attention to environmental protection and energy conservation. The commonly used heat pump fan coil has a low inlet and outlet temperature, which has a good energy saving effect, but the dry hot air blown out during heating in winter often makes people feel uncomfortable, the indoor air is not good, and the human comfort is reduced. Some high-temperature heating terminals, such as radiators, water floor heating, etc., use natural convection during heating, which can ensure the heating effect without blowing, but requires a lot of pipeline laying and renovation. At the same time, the inlet and outlet temperatures of the high-temperature heating terminal are relatively large. The high temperature heat source of the heat pump is at a high temperature for a long time, which will lead to a decrease in the energy efficiency coefficient COP of the system, and the energy saving effect of the system is not good.

At present, the optimization of air source heat pumps mainly focuses on two aspects: one is to optimize equipment, such as the optimization of compressors, evaporators, condensers, etc.; the other is to optimize the circulation mode of the system, such as the introduction of internal heat exchangers Heaters, injectors instead of throttles, etc. These technologies are helpful to improve the efficiency of heat pumps, but they cannot completely solve the problem, and some key problems remain to be solved.

SUMMARY OF THE INVENTION

In order to overcome the problem of low energy efficiency of the existing heat pump system, the utility model provides a direct heating type high-efficiency air source heat pump system that effectively improves the energy efficiency of the system and utilizes energy cascades with high efficiency.

The technical scheme adopted by the utility model to solve its technical problems is:

A direct heating high-efficiency air source heat pump system utilizing energy cascade, comprising a compressor, a four-way valve, a first air cooler, a second air cooler, a throttle valve, an evaporator, a gas-liquid separator, a first cut-off valve valve, second cut-off valve, third cut-off valve and one-way valve, the inlet of the compressor is connected with the first interface of the four-way valve, and the second interface of the four-way valve is respectively connected with the first interface of the first air cooler It is connected with the first port of the first solenoid valve, the second port of the four-way valve is connected with the first port of the evaporator, and the third port of the four-way valve is connected with the inlet of the gas-liquid separator; The second port is connected to the first port of the second globe valve and the first port of the third globe valve, respectively, the second port of the third globe valve is connected to the first port of the second air cooler, and the second port of the second globe valve is connected It is respectively connected with the first port of the throttle valve and the second port of the second air cooler, and the second port of the throttle valve is connected with the second port of the evaporator.

Further, the heat pump also includes a low temperature heating end, a high temperature heating end, a constant temperature water tank, a water pump, a fourth stop valve, a fifth stop valve, a sixth stop valve and a seventh stop valve, and the third stop valve of the first air cooler. The interface is connected with the inlet of the constant temperature water tank, the outlet of the constant temperature water tank is connected with the inlet of the fourth shut-off valve, the first interface of the fifth shut-off valve, and the inlet of the sixth shut-off valve, respectively, and the outlet of the fourth shut-off valve is connected with the inlet of the high temperature heating end Connected, the outlet of the high temperature heating end is connected with the inlet of the low temperature heating end and the second interface of the fifth stop valve respectively, the outlet of the low temperature heating end is connected with the inlet of the seventh stop valve, the outlet of the seventh stop valve is connected with the inlet of the water pump and The outlets of the sixth shut-off valve are respectively connected, and the outlet of the water pump is connected to the fourth port of the first air cooler.

Further, the heat pump also includes a sanitary hot water tank, the tap water interface is connected to the second inlet of the second air cooler, the second outlet of the second air cooler is connected to the sanitary hot water tank, and the The outlet is the sanitary hot water outlet.

Further, the heat pump further includes a temperature sensor, a variable frequency fan and a control device, the temperature sensor is located at the air side inlet of the evaporator and is connected to the control device; the variable frequency fan is also connected to the control device.

The technical idea of the utility model is to connect the low temperature heating terminal and the high temperature heating terminal in series. In this paper, the commonly used fan coil unit is used as the low temperature heating terminal and the radiator is used as the high temperature heating terminal as an example. The fan coil unit can be installed in a short time. In the bathroom, kitchen, storage room and other places used, the radiator can be installed in the bedroom that needs to be comfortable to ensure the best heating comfort for the residents. Based on the principle of energy cascade utilization, the high-temperature hot water is first used for heating through the radiator, and then the fan coil is heated to blow out hot air. The waste heat is reasonably utilized, the temperature of the high-temperature heat source of the heat pump is reduced, the operating conditions of the heat pump are optimized, and the The compressor consumes power and improves the system performance coefficient. At the same time, the system adopts the reverse cycle defrosting method, so that the evaporator can defrost quickly in winter.

The utility model is also provided with a second air cooler, and the medium temperature and high pressure gas passing through the first air cooler will be further cooled in the second air cooler for heating tap water to obtain sanitary hot water, thereby further reducing the discharge of the compressor. Air temperature and pressure to improve the energy efficiency of the system. Sanitary hot water does not need too high temperature (30℃-45℃), heating through the second air cooler can not only make full use of the waste heat, but also make sanitary hot water, which can kill two birds with one stone. In some extreme climates, the ambient temperature is very low, resulting in a low condensing temperature of the system, the temperature at the end of the heating through high temperature and low temperature is not enough to heat the hot water, or when the household has prepared enough hot water and does not need to make additional hot water, By adjusting the shut-off valve, the three modes of heating sanitary hot water, heating indoor rooms, and heating hot water while ensuring indoor warmth can be alternated.

The beneficial effects of the present utility model are mainly manifested in:

1. When the system is running, especially in low temperature in winter, the system has a higher energy efficiency coefficient COP and more energy saving than ordinary heat pump cycles. Heating the room at the same temperature consumes less electricity and is more efficient.

2. When a frost layer is formed on the surface of the evaporator in winter, the defrosting time required by the system is very short, which will not cause too much influence on the indoor heating, and the reliability of the system is very good.

3. Effectively utilize the waste heat released from the air cooler and adopt secondary cooling, which can not only produce sanitary hot water for indoor use, but also reduce throttling losses, which can be described as killing two birds with one stone.

Description of drawings

Fig. 1 is a schematic diagram of a direct heating high-efficiency air source heat pump system for energy cascade utilization, wherein 1: compressor; 2: first air cooler; 3: second air cooler; 4: throttle valve; 5: evaporator ;6: Gas-liquid separator; 7: Four-way valve; 8: First stop valve; 9: Second stop valve; 10: Third stop valve; 11: Constant temperature water tank; 12: High temperature heating end; 13: Low temperature heating End; 14: Fourth globe valve; 15: Fifth globe valve; 16: Sixth globe valve; 17: Seventh globe valve; 21: Water pump; 22: Sanitary hot water tank; 23: Frequency conversion fan; 24: Temperature sensor ;25: Control device

Fig. 2 is a schematic diagram of adding a sub-low temperature heating end to the system, wherein 1: compressor; 2: first air cooler; 3: second air cooler; 4: throttle valve; 5: evaporator; 6: gas Liquid separator; 7: Four-way valve; 8: First stop valve; 9: Second stop valve; 10: Third stop valve; 11: Constant temperature water tank; 12: High temperature heating end; 13: Low temperature heating end; 14: Sub-low temperature heating end; 15: Fourth globe valve; 16: Fifth globe valve; 17: Sixth globe valve; 18: Seventh globe valve; 19: Eighth globe valve; 20: Ninth globe valve; 21: Water pump ;22: Sanitary hot water tank; 23: Frequency conversion fan; 24: Temperature sensor; 25: Control device

Detailed ways

The present utility model will be further described below in conjunction with the accompanying drawings.

Referring to Figures 1 and 2, a direct heating high-efficiency air source heat pump system for energy cascade utilization includes a compressor, a four-way valve, a first air cooler, a second air cooler, a throttle valve, an evaporator, and an air conditioner. A liquid separator, a first cut-off valve, a second cut-off valve, a third cut-off valve and a one-way valve, the inlet of the compressor is connected to the first interface of the four-way valve, and the second interface of the four-way valve is respectively connected to the first interface of the four-way valve. The first interface of the air cooler is connected to the first interface of the first solenoid valve, the second interface of the four-way valve is connected to the first interface of the evaporator, and the third interface of the four-way valve is connected to the inlet of the gas-liquid separator; The second port of the first air cooler is connected to the first port of the second cut-off valve and the first port of the third cut-off valve, respectively, the second port of the third cut-off valve is connected to the first port of the second air cooler, and the second port of the third cut-off valve is connected to the first port of the second air cooler. The second ports of the two shut-off valves are respectively connected with the first ports of the throttle valve and the second ports of the second air cooler, and the second ports of the throttle valves are connected with the second ports of the evaporator.

Further, the heat pump also includes a low temperature heating end, a high temperature heating end, a constant temperature water tank, a water pump, a fourth stop valve, a fifth stop valve, a sixth stop valve and a seventh stop valve, and the third stop valve of the first air cooler. The interface is connected with the inlet of the constant temperature water tank, the outlet of the constant temperature water tank is connected with the inlet of the fourth shut-off valve, the first interface of the fifth shut-off valve, and the inlet of the sixth shut-off valve, respectively, and the outlet of the fourth shut-off valve is connected with the inlet of the high temperature heating end Connected, the outlet of the high temperature heating end is connected with the inlet of the low temperature heating end and the second interface of the fifth stop valve respectively, the outlet of the low temperature heating end is connected with the inlet of the seventh stop valve, the outlet of the seventh stop valve is connected with the inlet of the water pump and The outlets of the sixth shut-off valve are respectively connected, and the outlet of the water pump is connected to the fourth port of the first air cooler.

Further, the heat pump also includes a sanitary hot water tank, the tap water interface is connected to the second inlet of the second air cooler, the second outlet of the second air cooler is connected to the sanitary hot water tank, and the The outlet is the sanitary hot water outlet.

Further, the heat pump further includes a temperature sensor, a variable frequency fan and a control device, the temperature sensor is located at the air side inlet of the evaporator and is connected to the control device; the variable frequency fan is also connected to the control device.

Example 1: Normal working mode.

As shown in Figure 1, the normal working mode of the system has two cycles, the heat pump cycle and the water cycle. In the water circulation system in the normal working mode, the fifth shut-off valve 16 and the sixth shut-off valve 17 are closed, the fourth shut-off valve 15 and the seventh shut-off valve 18 are opened, and the high-temperature heating end is connected to the low-temperature heating end and are located in different rooms, respectively. The two are connected in series to work, and water is used as the refrigerant to absorb the heat released by the air cooler, and then heat the room. The low-temperature heating terminal can be installed in the bathroom, kitchen, storage room and other places that are not used for a long time, and the high-temperature heating terminal can be installed in the bedroom where comfort is required to ensure the best heating comfort. By connecting the two in series, the waste heat after the high temperature heating end works can be reused, reducing the temperature difference required for heat transfer, greatly reducing irreversible losses, and improving thermal efficiency. At the same time, the second air cooler 4 is also working, continuously heating the tap water to produce sanitary hot water and store it in the water tank 27 to meet the bathing needs of the households. Compared with the existing market that only uses the heat pump radiator as the heating device, the utility model has great energy saving, not to mention the heating furnace or electric heater with lower energy efficiency. If the resident has prepared enough sanitary hot water, he can choose to open the second shut-off valve 9, close the first shut-off valve 8 and the third shut-off valve 10, and stop producing hot water.

Example 2: Low temperature heating terminal working mode or high temperature heating terminal working mode

In some special cases, the occupant may stay in one room so it is not necessary for both heating devices to be activated. The utility model adds four cut-off valves to the water circulation system to control two heating devices. For example, only the low-temperature heating terminal 12 needs to work without the high-temperature heating terminal 13, that is, the fourth stop valve 15 and the sixth stop valve 17 are closed, and the fifth stop valve 16 and the seventh stop valve 18 are opened. When only the high-temperature heating terminal is required When working without the need for low-temperature heating end work, close the seventh shut-off valve and open the fourth, fifth and sixth shut-off valves. At the same time, the second air cooler 4 is also working, continuously heating the tap water to prepare sanitary hot water and store it in the water tank 27 to meet the bathing needs of the households. If the household has prepared enough sanitary hot water, he can choose to open the second shut-off valve 9, close the first shut-off valve 8 and the third shut-off valve 10, and stop producing hot water.

Example 3: Reverse cycle defrost mode

As shown in Figure 1, when the temperature of the surface of the evaporator 5 is lower than the dew point temperature in the air, the water vapor in the air will gradually condense on the surface of the evaporator to form a frost layer, which is a very common phenomenon in winter in the north. The utility model uses the reverse cycle defrosting system for the direct heating high-efficiency air source heat pump system for energy cascade utilization. When the frost layer on the evaporator is too thick to affect the work, the four-way valve 7 will automatically turn to adjust to the heating mode. At this time, the original air cooler 2 will be used as an evaporator, and the original evaporator will be used as an air cooler to absorb the heat released by the compressor, so as to achieve the purpose of melting the frost layer. When the frost layer is melted, the four-way valve turns again and returns to the normal working mode.

Example 4: Heating sanitary hot water mode

As shown in Figure 1, the system is also provided with an intercooler 4, the purpose of which is to produce sanitary hot water. The medium temperature and high pressure gas passing through the first air cooler will be further cooled in the second air cooler to heat tap water to obtain sanitary hot water. The sanitary hot water tank 24 is installed in the bathroom. During the day, with the heating of the room, hot water will be continuously stored in the constant temperature hot water tank for use by the residents at night. When households urgently need hot water, they can also open the first shut-off valve and the third shut-off valve, and close the second shut-off valve. All the heat in the compressor will be released through the second air cooler to heat the tap water to achieve rapid production of sanitary hot water purpose.

Example 5: Multi-stage heating mode

As shown in Figure 2, the system adds a sub-low temperature heating terminal 14 and two shut-off valves to the original system, thereby further reducing the temperature of the heat pump heat source and improving the operating efficiency of the heat pump. By analogy, the heating end of the heat pump is divided into multiple stages, and the energy efficiency coefficient COP is further improved on the original basis. In principle, the number of stages at the end of different temperature positions can be continuously increased. Improve the working conditions of the system.

Example 6: Mode of making hot water in summer

In summer, households do not need heating mode, but only need the system to provide a certain amount of domestic hot water every day, that is, the structure in Figure 2 is adopted. Because the working conditions of each component of this system are designed based on the conditions of minus 20 ℃ in winter, the high evaporating temperature in summer will cause the compressor to consume too much power and burn out. Therefore, in this system, a temperature sensor is installed at the inlet of the air side of the evaporator and is connected with the control device, and the other end of the control device is connected with the variable frequency fan of the evaporator. When the air temperature exceeds the set value, the control device controls the speed of the variable frequency fan to decrease, the temperature difference of the evaporator increases, and the temperature of the refrigerant in the evaporator is reduced, thereby reducing the power consumption of the compressor. Ensure that the system operates under reasonably safe conditions.

Claims (4)

1. A directly-heated high-efficiency air source heat pump system for energy gradient utilization is characterized by comprising a compressor, a four-way valve, a first air cooler, a second air cooler, a throttle valve, an evaporator, a gas-liquid separator, a first stop valve, a second stop valve, a third stop valve and a one-way valve, wherein the inlet of the compressor is connected with a first interface of the four-way valve, a second interface of the four-way valve is respectively connected with a first interface of the first air cooler and a first interface of a first electromagnetic valve, a second interface of the four-way valve is connected with a first interface of the evaporator, a third interface of the four-way valve is connected with the inlet of the gas-liquid separator, a second interface of the first air cooler is respectively connected with a first interface of the second stop valve and a first interface of the third stop valve, a second interface of the third stop valve is connected with a first interface of the second air cooler, a second interface of the second stop valve is respectively connected with a first interface of the throttle valve and a second interface of the second air cooler, the second port of the throttle valve is connected with the second port of the evaporator.

2. The directly-heated high-efficiency air source heat pump system for energy cascade utilization according to claim 1, wherein the heat pump further comprises a low-temperature heating end, a high-temperature heating end, a constant-temperature water tank, a water pump, a fourth stop valve, a fifth stop valve, a sixth stop valve and a seventh stop valve, the third interface of the first air cooler is connected with the inlet of the constant-temperature water tank, the outlet of the constant-temperature water tank is connected with the inlet of the fourth stop valve, the first interface of the fifth stop valve and the inlet of the sixth stop valve respectively, the outlet of the fourth stop valve is connected with the inlet of the high-temperature heating end, the outlet of the high-temperature heating end is connected with the inlet of the low-temperature heating end and the second interface of the fifth stop valve respectively, the outlet of the low-temperature heating end is connected with the inlet of the seventh stop valve, the outlet of the seventh stop valve is connected with the, and the outlet of the water pump is connected with the fourth interface of the first air cooler.

3. The energy cascade utilization direct-heating type high efficiency air source heat pump system according to claim 1 or 2, wherein the heat pump further comprises a sanitary hot water tank, the tap water port is connected with the second inlet of the second air cooler, the second outlet of the second air cooler is connected with the sanitary hot water tank, and the outlet of the sanitary hot water tank is the sanitary hot water outlet.

4. The energy cascade utilization, direct heating, high efficiency air source heat pump system as recited in claim 1 wherein said heat pump further comprises a temperature sensor, a variable frequency fan and a control means, said temperature sensor located at the evaporator air side inlet and connected to the control means; the variable frequency fan is also connected with the control device.

Images