CN211782094U

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

Info

Publication number: CN211782094U
Application number: CN201921898626.3U
Authority: CN
Inventors: 徐英杰; 毛成斌
Original assignee: Zhejiang University of Technology ZJUT
Current assignee: Zhejiang University of Technology ZJUT
Priority date: 2019-11-06
Filing date: 2019-11-06
Publication date: 2020-10-27
Anticipated expiration: 2029-11-06

Abstract

A directly-heated high-efficiency air source heat pump system with energy gradient utilization comprises a heat pump cycle, a water cycle and a sanitary hot water cycle. The utility model discloses can enough guarantee indoor heating, can conveniently prepare sanitary hot water again, guarantee that the system stabilizes high-efficient operation throughout the year. First air cooler heating thermostatic water tank passes through the terminal heat supply that realizes of multistage heating, establishes ties low temperature heating end and high temperature heating end at the water tank exit to control through 4 stop valves, realize the cascade utilization of energy, can enough satisfy the requirement of resident family's travelling comfort, can not cause too much waste again, can kill two birds with one stone. And simultaneously, the utility model discloses a 3 stop valve control second air coolers heating health hot water, satisfy the resident family water demand. The utility model provides a directly-heated high-efficient air source heat pump system that energy efficiency, the higher energy step of efficiency of effective lift system utilized.

Description

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

Technical Field

The utility model belongs to the heat pump field relates to a directly-heated type heat pump.

Background

The heat pump is a device which changes a large amount of low-temperature energy into high-temperature energy by using a small amount of driving energy. The heat source medium can be divided into an air energy heat pump, a water source heat pump and a ground source heat pump. The existing air energy heat pump can be divided into a circulating type and a directly-heated type according to the operation mode. The direct-heating heat pump unit has the advantages that the water inlet temperature is always kept constant, the heat exchange efficiency is high, the heat absorption capacity is strong, the condensing temperature, the exhaust pressure and the running current are stable, and the running life of the compressor is greatly prolonged, so that the direct-heating heat pump unit is more and more emphasized by people in practical engineering.

The temperature in winter in the north of China is often very low, and some rural areas often adopt coal fired boilers to heat, and in recent years, environmental and energy problems are more and more concerned, and the country also more and more attaches importance to environmental protection and energy saving, and the air energy heat pump obtains a large amount of popularization. The inlet and outlet temperatures of a common heat pump fan coil are low, so that a good energy-saving effect is achieved, but dry hot air blown out in winter heating often makes people feel uncomfortable, indoor air is poor, and the comfort level of a human body is reduced. Some high temperature heating ends, such as radiator, water floor heating etc. adopt natural convection when heating, and no blowing sense can guarantee the heating effect again, but needs a large amount of pipe laying and transformation, and simultaneously, the exit temperature of high temperature heating end is bigger, and the heat pump high temperature heat source is in higher temperature for a long time, can lead to the efficiency coefficient COP of system to descend, and the energy-conserving effect of system is not good.

Currently, the optimization of air source heat pumps mainly focuses on two aspects: firstly, optimizing equipment, such as a compressor, an evaporator, a condenser and the like; and secondly, optimizing the circulation mode of the system, such as introducing an internal heat exchanger, replacing a throttle valve with an ejector and the like. These techniques have helped to improve the efficiency of heat pumps, but they do not solve the problem completely, and some key problems remain to be solved.

Disclosure of Invention

In order to overcome the lower not enough of system efficiency of having the heat pump, the utility model provides an effective directly-heated type high-efficient air source heat pump system that lift system efficiency, the higher energy step of efficiency utilized.

The utility model provides a technical scheme that its technical problem adopted is:

a directly-heated high-efficiency air source heat pump system for energy gradient utilization comprises 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, and a third interface of the four-way valve is connected with the inlet of the gas-liquid separator; the second interface of the first air cooler is connected with the first interface of the second stop valve and the first interface of the third stop valve respectively, the second interface of the third stop valve is connected with the first interface of the second air cooler, the second interface of the second stop valve is connected with the first interface of the throttle valve and the second interface of the second air cooler respectively, and the second interface of the throttle valve is connected with the second interface of the evaporator.

Further, 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, wherein a third interface of the first air cooler is connected with an inlet of the constant-temperature water tank, an outlet of the constant-temperature water tank is connected with an inlet of the fourth stop valve, a first interface of the fifth stop valve and an inlet of the sixth stop valve respectively, an outlet of the fourth stop valve is connected with an inlet of the high-temperature heating end, an outlet of the high-temperature heating end is connected with an inlet of the low-temperature heating end and a second interface of the fifth stop valve respectively, an outlet of the low-temperature heating end is connected with an inlet of the seventh stop valve, an outlet of the seventh stop valve is connected with an inlet of the water pump and an outlet of the sixth stop valve respectively.

Furthermore, the heat pump further comprises a sanitary hot water tank, the tap water interface is connected with a second inlet of the second air cooler, a second outlet of the second air cooler is connected with the sanitary hot water tank, and an outlet of the sanitary hot water tank is a sanitary hot water outlet.

Furthermore, the heat pump also comprises a temperature sensor, a variable frequency fan and a control device, wherein the temperature sensor is positioned at the air side inlet of the evaporator and is connected with the control device; the variable frequency fan is also connected with the control device.

The technical conception of the utility model is as follows: the low-temperature heating terminal and the high-temperature heating terminal are connected in series, a common fan coil is used as the low-temperature heating terminal, the heating radiator is used as the high-temperature heating terminal, the fan coil can be installed in places where a toilet, a kitchen, a storeroom and the like are not used for a long time, and the heating radiator can be installed in a bedroom where comfort needs to be guaranteed so as to guarantee the best heating comfort of residents. Based on the principle of energy cascade utilization, high-temperature hot water is heated by the heating radiators and then heated by the fan coil, so that hot air is blown out, the waste heat is reasonably utilized, the temperature of a high-temperature heat source of the heat pump is reduced, the operation condition of the heat pump is optimized, the power consumption of the compressor is reduced, and the performance coefficient of the system is improved. Meanwhile, the system adopts a reverse cycle defrosting method so as to quickly defrost the evaporator in winter.

The utility model discloses still be equipped with the second air-cooler, the medium temperature high pressure gas through first air-cooler can further lower the temperature in the second air-cooler for thereby heating the running water and obtaining sanitary hot water, thereby further reduce the exhaust temperature and the pressure of compressor, improve the efficiency of system. The sanitary hot water does not need too high temperature (30 ℃ -45 ℃) and can be heated by the second air cooler, thereby not only fully utilizing the waste heat, but also preparing the sanitary hot water, which can kill two birds with one stone. In some extreme climates, the ambient temperature is very low, so that the condensation temperature of the system is not high, the temperature at the tail ends of high-temperature heating and low-temperature heating is not enough to heat hot water, or when a resident prepares enough hot water without additionally preparing hot water, the alternation of three modes of heating sanitary hot water, heating rooms in the room and heating the hot water and simultaneously ensuring indoor warming can be realized by adjusting the stop valve.

The beneficial effects of the utility model are that:

1. when the system works and operates, particularly operates at low temperature in winter, compared with the common heat pump cycle, the energy efficiency coefficient COP of the system is higher, and the system is more energy-saving. The same temperature for indoor heating consumes less electricity, and the efficiency is higher.

2. When frost layers are generated on the surface of the evaporator in winter, the defrosting time required by the system is very short, the indoor heating cannot be greatly influenced, and the reliability of the system is very good.

3. The waste heat discharged from the air cooler is effectively utilized, and the secondary cooling is adopted, so that the sanitary hot water can be prepared for indoor use, the throttling loss can be reduced, and the double-effect can be achieved.

Drawings

Fig. 1 is a schematic diagram of a directly-heated high-efficiency air source heat pump system with energy cascade utilization, wherein 1: a compressor; 2: a first air cooler; 3: a second air cooler; 4: a throttle valve; 5: an evaporator; 6: a gas-liquid separator; 7: a four-way valve; 8: a first shut-off valve; 9: a second stop valve; 10: a third stop valve; 11: a constant temperature water tank; 12: a high temperature heating terminal; 13: a low temperature heating terminal; 14: a fourth stop valve; 15: a fifth stop valve; 16: a sixth stop valve; 17: a seventh stop valve; 21: a water pump; 22: a sanitary hot water tank; 23: a variable frequency fan; 24: a temperature sensor; 25: control device

Fig. 2 is a schematic diagram of the system with a secondary low temperature heating terminal, wherein 1: a compressor; 2: a first air cooler; 3: a second air cooler; 4: a throttle valve; 5: an evaporator; 6: a gas-liquid separator; 7: a four-way valve; 8: a first shut-off valve; 9: a second stop valve; 10: a third stop valve; 11: a constant temperature water tank; 12: a high temperature heating terminal; 13: a low temperature heating terminal; 14: a secondary low temperature heating terminal; 15: a fourth stop valve; 16: a fifth stop valve; 17: a sixth stop valve; 18: a seventh stop valve; 19: an eighth stop valve; 20: a ninth cut-off valve; 21: a water pump; 22: a sanitary hot water tank; 23: a variable frequency fan; 24: a temperature sensor; 25: control device

Detailed Description

The present invention will be further described with reference to the accompanying drawings.

Referring to fig. 1 and 2, a directly-heated high-efficiency air source heat pump system for energy gradient utilization includes 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 an 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, and a third interface of the four-way valve is connected with an inlet of the gas-liquid separator; the second interface of the first air cooler is connected with the first interface of the second stop valve and the first interface of the third stop valve respectively, the second interface of the third stop valve is connected with the first interface of the second air cooler, the second interface of the second stop valve is connected with the first interface of the throttle valve and the second interface of the second air cooler respectively, and the second interface of the throttle valve is connected with the second interface of the evaporator.

Example 1: and (4) a normal working mode.

As shown in FIG. 1, the normal operation mode of the system has two cycles, a heat pump cycle and a water cycle. In the water circulation system under the normal working mode, the fifth stop valve 16 and the sixth stop valve 17 are closed, the fourth stop valve 15 and the seventh stop valve 18 are opened, the high-temperature heating tail end and the low-temperature heating tail end are connected and are respectively positioned in different rooms, the high-temperature heating tail end and the low-temperature heating tail end are connected in series to work, water is used as secondary refrigerant, heat emitted from the air cooler is absorbed, and indoor heating is performed. The low temperature heating end can be arranged in a toilet, a kitchen, a storeroom and the like which are not used for a long time, and the high temperature heating end can be arranged in a bedroom which needs to be comfortable, so that the best heating comfort is ensured. Through connecting the two in series, the waste heat after the terminal work of high temperature heating can be utilized again for reduced the required difference in temperature of heat transfer, reduced irreversible loss greatly, improved the thermal efficiency. Meanwhile, the second air cooler 4 is also working to continuously heat tap water to produce sanitary hot water to be stored in the water tank 27, so as to meet the bathing requirements of the residents. The utility model discloses comparing and having played current market and only having used the heat pump radiator as heating system, there is very big energy-conservation, let alone be lower heating stove of efficiency or electric heater. If the household has prepared enough sanitary hot water, the second stop valve 9 can be selectively opened, the first stop valve 8 and the third stop valve 10 are closed, and the hot water preparation is stopped.

Example 2: low temperature heating end working mode or high temperature heating end working mode

In some special cases, a resident may be in a room and therefore not require both heaters to be active. The utility model discloses installed two heating equipment of 4 check-valve control additional in water circulating system. For example, only the low temperature heating terminal 12 is required to be operated and the high temperature heating terminal 13 is not required to be operated, that is, the fourth and sixth cut-off

valves

15 and 17 are closed, and the fifth and seventh cut-off

valves

16 and 18 are opened, and when only the high temperature heating terminal is required to be operated and the low temperature heating terminal is not required to be operated, the seventh cut-off valve is closed and the fourth, fifth and sixth cut-off valves are opened. Meanwhile, the second air cooler 4 is also working to continuously heat tap water to produce sanitary hot water to be stored in the water tank 27, so as to meet the bathing requirements of the residents. If the household has prepared enough sanitary hot water, the second stop valve 9 can be selectively opened, the first stop valve 8 and the third stop valve 10 are closed, and the hot water preparation is stopped.

Example 3: reverse circulation defrosting mode

As shown in fig. 1, when the temperature of the surface of the evaporator 5 is lower than the dew point temperature of the air, water vapor in the air gradually condenses on the surface of the evaporator to form a frost layer, which is a very common phenomenon in the winter season in the north. The utility model discloses the high-efficient air source heat pump system of directly-heated type that defrosting system is used for energy step to utilize will reverse circulation, when the evaporator goes up the too thick influence during operation in frost layer, cross valve 7 can turn to voluntarily, transfers into the mode of heating, and at this moment, original air cooler 2 can regard as the evaporimeter, and original evaporimeter then can regard as the heat that emits in the air cooler absorption compressor to reach the purpose that melts the frost layer. And after the frost layer is melted, the four-way valve turns again to restore the normal working mode.

Example 4: heating sanitary hot water mode

As shown in fig. 1, the system is also provided with an intercooler 4, the purpose of which is to make sanitary hot water. The medium-temperature high-pressure gas passing through the first air cooler is further cooled in the second air cooler for heating tap water to obtain sanitary hot water. The sanitary hot water tank 24 is installed in a bathroom, and hot water is continuously stored in the constant temperature hot water tank along with indoor heating in the daytime and is supplied to residents at night. When the resident urgently needs hot water, the first stop valve and the third stop valve can be opened, the second stop valve is closed, all heat in the compressor can be discharged through the second air cooler, tap water is heated, and the purpose of quickly preparing sanitary hot water is achieved.

Example 5: multi-stage heating mode

As shown in fig. 2, the system is additionally provided with a secondary low-temperature heating terminal 14 and two stop valves on the original system, so that the heat source temperature of the heat pump is further reduced, and the operating efficiency of the heat pump is improved. By analogy, the heating tail end of the heat pump is divided into multiple stages, the energy efficiency coefficient COP is further improved on the original basis, the stage number of the tail ends of different temperature positions can be continuously increased in principle, the specific stage number can be changed according to the environmental temperature and the economic condition, and the working condition of the system is greatly improved.

Example 6: mode for preparing hot water in summer

In summer, the household does not need a heating mode, and only needs to provide a certain amount of daily domestic hot water by the system, namely the structure in fig. 2 is adopted. Because the working conditions of all parts of the system are designed based on the condition of 20 ℃ below zero in winter, the compressor consumes too much power and burns out due to overhigh evaporation temperature in summer. Therefore, the system is provided with a temperature sensor at the air side inlet of the evaporator and is connected with a control device, and the other end of the control device is connected with a variable frequency fan of the evaporator. When the air temperature exceeds a set value, the control device controls the rotating speed of the variable frequency fan to be reduced, the temperature difference of the evaporator is increased, and the temperature of the refrigerant in the evaporator is reduced, so that the power consumption of the compressor is reduced. The system is ensured to operate under reasonable and safe conditions.

Claims

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.