Energy storage heat pump coupling system and heating regulation method thereof

Abstract

The present invention discloses an energy storage heat pump coupling system, including an air-cooled hot and cold water unit, a water source heat pump and a heat storage / cold device. When heating: the water source heat pump input end is connected to the output of the air-cooled hot and cold water unit, the heat storage device input end is connected to the output of the water source heat pump, and the other output of the water source heat pump is connected to the output of the heat storage device and then connected to the user load system; when cooling: the air-cooled hot and cold water unit, the water source heat pump and the heat storage / cold device are respectively connected to the user load system, and the other output of the water source heat pump is connected to the input of the heat storage / cold device. This technology uses the coupling method of different devices to store energy and utilize the valley electricity price policy to ensure continuous load supply throughout the day, fully absorb the nighttime electricity, and achieve "peak shaving and valley filling, valley heat storage", ensure the balance of power generation and transmission and distribution in a certain area, increase the benefits of power generation and transmission and distribution enterprises, and solve the problem of clean energy heating. In special outdoor environments, it adjusts the equipment operation strategy to maintain the optimal system energy efficiency and reduce operating costs.

Description

Technical Field

[0001] The technology of this application mainly relates to the field of heat supply and regulation technology in industry and life, especially to the use of thermal energy coupling between different thermal equipment under different geographical and climatic environments to achieve temperature regulation inside working and living building environments, that is, a storage heat pump coupling system and its heating regulation method. Background Art

[0002] In industry and life, the thermal system is one of the necessary conditions to ensure the production and living environment. It transports heat to the production and living building environment through different forms of heat source heat pumps. In architectural planning and design, the design of the thermal system has become an important content. The heat of the thermal system has different sources: air source heat pump system, water source heat pump system, soil source heat pump system, etc. These different thermal systems have certain limitations and applicability in the actual engineering application process: when the outdoor air temperature is lower than -20℃, the efficiency of the air source thermal device is seriously attenuated, the heating temperature is low, and the heating function is basically lost; the limitation of the application of the water source thermal system is that it requires a large volume of groundwater or surface water, which has a certain impact on the environment; the soil source heat pump requires a large land area, and the cold and heat are unbalanced in winter and summer, and the soil cold accumulation is serious.

[0003] China has a vast territory, with significant climate differences between the north and south, and there is also diversity in heat supply. Common heat supply includes natural gas heat supply and electric heat supply. Natural gas and electricity have become the preferred strategy for urban energy complementarity. At present, natural gas in towns is mainly used for cooking and heating. The use of cooking natural gas is basically balanced every month throughout the year, but natural gas for heating is consumed in large quantities only in winter. In order to ensure the demand for natural gas for heating in winter, it is necessary to build natural gas storage stations and transmission and distribution pipelines that meet the winter heating and cooking loads. The investment is huge, but these facilities are operated at a lower load in the non-heating season, and the natural gas storage and distribution capacity cannot be effectively utilized, resulting in a waste of investment. The peak of urban power load often occurs in summer due to the widespread use of air conditioning. In order to meet the peak load of summer power, a large amount of funds are also needed to build power plants, transmission and distribution networks and substation facilities. The power generation and transmission and distribution capabilities are also not utilized in the non-air conditioning season, and fixed asset investment is not efficiently utilized. The complementary energy utilization of natural gas and electricity can effectively solve the above two problems: the appropriate development of gas absorption refrigeration in summer can give full play to the capacity of gas storage and transmission and distribution pipelines, while reducing the pressure on power generation and transmission and distribution networks caused by summer air-conditioning loads and reducing investment in power facilities; the development of electric heating in winter can effectively reduce investment in gas storage and transmission and distribution pipelines, while objectively absorbing the redundant capacity of urban power generation and transmission and distribution networks, thereby providing an efficient and healthy development direction for urban energy supply and consumption.

[0004] The advantages of natural gas heating are: (1) flexible construction, centralized management of gas boilers, and easy repair; (2) the heating temperature can be lowered or stopped during holidays or at night when no one is around, saving gas and operating costs. However, natural gas is a non-renewable resource, and its main disadvantages are: (1) the heat loss of the heat source equipment (gas boiler) for natural gas heating is large; (2) natural gas supply is prone to shortage in winter. China currently has a serious shortage of underground gas storage. The gas volume of underground gas storage is 6.1 billion cubic meters, accounting for only about 3% of the total natural gas consumption, far lower than the 17% ratio of the United States and Russia. The current domestic natural gas shortage is 80 million cubic meters / day, a gap of about 10%. (3) The peak-shaving capacity of natural gas is seriously insufficient; once a region uses natural gas for heating on a large scale, the difference in gas consumption between the heating season and the non-heating season will be very large. Taking Beijing as an example, in the non-heating season, Beijing's natural gas is mainly used for gas peak-shaving power generation, industrial gas boilers, residents' small gas hot water boilers, and gas stoves in the kitchen; in winter, due to the demand for heating, the gas consumption increases. Regional gas boilers for heating and small household gas heating boilers for heating are gas demands that only occur during the heating season. Taking Beijing as an example, Beijing's heating season is about 4 months, accounting for 1 / 3 of the whole year, but the gas consumption exceeds half of the whole year. In addition, the heating gas consumption is proportional to the outdoor temperature, and the gas consumption fluctuates greatly. Taking a northern city as an example, the heating gas consumption on the day of the daily average minimum temperature and the daily average maximum temperature in January can differ by 2.5 times. The problem of hourly peak-shaving of urban gas is generally solved by using gas storage facilities to store a certain amount of gas. The layout of natural gas storage facilities and pipelines is not in place, which greatly reduces the effectiveness of gas source emergency dispatching and the peak-shaving capacity is insufficient during the peak period of the heating season.

[0005] Advantages of electric heating: (1) Electric energy transmission is convenient and loss is small. (2) Electric energy is most convenient to convert into other forms of energy. The conversion of electric energy into other forms of energy not only requires simple equipment but also has high efficiency. (3) The power generation and transmission and distribution capacity of power facilities is large. The current economic development has shifted from the extensive growth that relied on "high investment, high energy consumption, high pollution and low efficiency" to the intensive growth of "low carbon, environmental protection and high efficiency". Under the current and future low-carbon, environmental protection and high-efficiency industrial model, the power load will be reduced, and the power generation and transmission and distribution capacity of the built power plants, transmission and distribution networks and substation facilities will be large, and there will be no problem of natural gas heating. (4) Electric heating is more economical. (a) With the popularization of the concept of clean energy, more and more enterprises and funds have entered the photovoltaic and wind power generation industries. my country has now become the country with the fastest growth rate of photovoltaic and wind power generation installed capacity in the world. In the foreseeable future, it is bound to reduce the comprehensive cost of power generation, thereby reducing the electricity price at the consumer end, providing predictable industry guarantees for the economy of electric heating. (b) With the increasing maturity of various heat storage technologies, the use of night-time off-peak electricity has become a necessary means for electric heating systems. The night-time off-peak electricity price is only 1 / 2-1 / 3 of the daytime flat electricity price, and the peak-valley electricity price system is being implemented nationwide, providing a strong institutional guarantee for the economic efficiency of electric heating. (c) With the increasing advancement of heat pump technology, its efficiency is constantly improving, and the applicability of heat pump heating has been greatly improved. Groundwater, surface water, sewage, air, and soil can all become heat sources for heat pump heating. Technological progress has improved the efficiency of electric heating. At present, in areas with hot summers and cold winters, the efficiency of heat pump heating can reach 3-5, that is, 1 unit of electricity can produce 3-5 units of heat energy, which provides a solid technical guarantee for the economic efficiency of electric heating. (d) With the continuous improvement of the national power transmission and distribution network, it has now been basically realized that there is electricity supply in places where people live, work, and live. Electricity has become a more convenient means of energy utilization in the current society, which provides a more reliable and universal guarantee for the economic efficiency of electric heating. (e) Due to the great imbalance in electricity load during the day and at night, electricity consumption is high during the day and low at night, resulting in a large imbalance in power generation and power transmission and distribution.

[0006] How to balance the imbalance of electricity load during the day and night in the heat supply process, improve the effectiveness of heat supply, achieve balanced energy supply, and solve the problem of clean energy heating is the technological frontier of the development of thermal system technology. Summary of the invention

[0007] The present invention is aimed at the heat supply balance defects in urban production and life. With the help of the coupling mode of different thermal equipment, a heat storage technology is adopted to design and implement an energy storage heat pump coupling system. At the same time, the heat storage device of the system is used to achieve the peak and valley balance of heating and electricity consumption, improve the operating efficiency of the thermal system, and reduce the operating cost.

[0008] To achieve the above invention purpose, the technical solution adopted in this application is: a storage heat pump coupling system, the system includes an air-cooled hot and cold water unit, a water source heat pump unit and a heat storage / cold device. When the system is used as a heating system: the input end of the water source heat pump unit is connected to the output of the air-cooled hot and cold water unit, the input end of the heat storage / cold device is connected to an output of the water source heat pump unit, and the other output of the water source heat pump unit is connected to the output of the heat storage / cold device and then connected to the user load system; when the system is used as a refrigeration system: the air-cooled hot and cold water unit, the water source heat pump unit and the heat storage / cold device are respectively connected to the user load system, and the other output of the water source heat pump unit is connected to the input of the heat storage / cold device. In the storage heat pump coupling system, the advantages of the air source heat pump and the water source heat pump are effectively coupled through heat storage technology. The system consists of a low-temperature air source heat pump, i.e., an air-cooled hot and cold water unit, and a high-temperature high-temperature water source heat pump unit, i.e., a water source heat pump unit. During the night valley period, high-temperature water of ≥60°C can be generated and stored in the energy storage device. The system solves the limitations and performance weaknesses of pure air source heat pumps and water source heat pumps. The system maximizes the use of air energy, "peak-valley" electricity price differences and other renewable energy sources to achieve multi-energy complementarity and comprehensive utilization, and build a reliable heating / cooling system suitable for areas with heating and cooling needs.

[0009] In the energy storage heat pump coupling system of the present application, both the air-cooled hot and cold water units and the water source heat pump units are powered by external power equipment.

[0010] In order to improve the utilization efficiency more efficiently, the user load system is a plurality of parallel systems connected to the mixing pipelines of the heat storage / cooling equipment and the water source heat pump unit respectively.

[0011] This application uses the energy storage heat pump coupling system to achieve heating regulation, and the regulation steps are:

[0012] (1) During the off-peak period of electricity consumption, the air-cooled hot and cold water units are driven by electricity. Based on the working principle of the heat pump, the heat transfer medium (usually water) is raised from the local surface water temperature to the set temperature suitable for the working point of the water source heat pump. As the source side energy supply of the water source heat pump unit, the water source heat pump unit directly supplies part of the output high-temperature heating hot water to the user load through the secondary temperature increase of the heat transfer medium, and transmits the other part to the heat storage equipment for heat storage;

[0013] (2) During peak electricity consumption periods, the energy storage device is preferentially used as the main heat source to supply heat to the user load. During the peak heat load demand period in winter: if the external environment is low temperature and high humidity, the air-cooled hot and cold water unit is used to provide input to the water source heat pump unit, and the output of the water source heat pump unit is then output together with the energy storage device as the peak heat for this period to supply the user load; if the external environment is low humidity, the water source heat pump unit stops working, and the output of the air-cooled hot and cold water unit is output together with the energy storage device as the peak heat for this period to supply the user load; the high and low humidity standards described here are around 0°C and 70% humidity, and the value of the absolute humidity content of the air at this operating point is regarded as high humidity.

[0014] During the above heat regulation process, due to the differences in environmental climate in different regions (south and north), in the humid environment of the south, frost is easy to form after the temperature drops, especially on the surface of the water source heat pump unit, which condenses to form a frost layer, thus affecting the normal operation of the unit. Therefore, the air-cooled hot water unit is used as the primary heat source supply to provide a medium with a certain temperature of heat for the water source heat pump. The water source heat pump unit works on this basis to avoid the occurrence of frost on the surface of the unit. Due to the superiority of energy storage equipment in storing high-temperature heat, the output of energy storage equipment is preferred as the energy source in the use of user loads, and air-cooled hot and cold water units or water source heat pumps are used as auxiliary heat supplements.

[0015] When the energy storage heat pump coupling system of the present application realizes cooling regulation, step (1) directly uses the water source heat pump unit (3) to store low-temperature medium for the heat storage / cold equipment during the valley power stage at night; step (2) first uses the water source heat pump unit as the basis to supply the user load under the cooling condition, and uses the cold storage device as a peak-shaving device during the peak power consumption period and the peak cooling load demand period during the daytime. During the peak cooling load demand period, the air-cooled hot and cold water unit is simultaneously turned on as a cold source to supplement the user load.

[0016] The heat storage heating / cooling method of the technical solution of the present application converts cheap electricity into heat energy and stores it by heating for 8-10 hours during the off-peak electricity price period at night every day (which varies according to the peak and off-peak electricity period division in different regions); the power is cut off during the peak electricity consumption period of 14-16 hours during the day of the next day, and the stored heat is released to supply heat to the heating system. It not only takes advantage of the off-peak electricity price policy, but also can continuously release heat to the heating system 24 hours a day, fully absorbing excess electricity at night, realizing "peak shaving and valley filling, valley heat storage, and halving electricity charges", ensuring the balance of power generation and transmission and distribution in a certain area, increasing the effects of power generation enterprises and transmission and distribution enterprises, and solving the problem of clean energy heating at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The energy storage heat pump coupling system of the present application realizes the connection mode when heating;

[0018] Figure 2 The connection method of the energy storage heat pump coupling system of the present application when realizing cooling;

[0019] In the figure, 1. Air-cooled hot and cold water units; 2. Power equipment; 3. Water source heat pump units; 4. User load system; 5. Valve; 6. Heat storage / cold equipment. DETAILED DESCRIPTION

[0020] The technical solution of the present application is explained below in conjunction with a specific heating or cooling implementation scheme. Figure 1 The figure shows the connection mode of the energy storage heat pump coupling system of the application for heating. The composition and connection of the system are as follows: the input end of the water source heat pump unit 3 is connected to the output of the air-cooled hot and cold water unit 1, the input end of the heat storage device 6 is connected to an output of the water source heat pump unit, and the other output of the water source heat pump unit is connected to the output of the heat storage device and then connected to the user load system 4. The working power of the whole system is provided by the external power equipment 2; the peak load control process is as follows: (1) During the low-peak period of electricity consumption, the air-cooled hot and cold water unit is driven by electricity. Based on the working principle of the heat pump, the heat transfer medium (generally water) is raised from the local surface water temperature to the set temperature suitable for the working point of the water source heat pump as the source side energy supply of the water source heat pump unit. The water source heat pump unit raises the secondary temperature of the heat transfer medium to the high temperature heating output Part of the hot water is directly supplied to the user load, and the other part is transmitted to the heat storage device for heat storage; (2) During the peak electricity consumption period, the energy storage device is used as the main heat source to supply heat to the user load. During the peak heat load demand period in winter: if the external environment is low temperature and high humidity, the air-cooled hot and cold water unit is used to provide input to the water source heat pump unit, and then the output of the water source heat pump unit is used as the peak heat for this period and output together with the energy storage device to supply the user load; if the external environment is in a low humidity state, the water source heat pump unit stops working, and the output of the air-cooled hot and cold water unit is used as the peak heat for this period and output together with the energy storage device to supply the user load; the high and low humidity standards described here are around 0°C and 70% humidity. The value of the absolute humidity content of the air at this operating point is regarded as high humidity.

[0021] The energy storage heat pump coupling system of the present application can also be used as a refrigeration system. In this case, the air-cooled hot and cold water unit 1, the water source heat pump unit 3 and the cold storage device 6 are respectively connected to the user load system, and the other output of the water source heat pump unit is connected to the input of the cold storage device. When in use, step (1) directly uses the water source heat pump unit 3 to store low-temperature medium for the cold storage device during the valley power stage at night; step (2) first uses the water source heat pump unit as the basis to supply the user load in the case of refrigeration, and uses the cold storage device as a peak-shaving device during the peak power consumption period and the peak period of cold load demand during the daytime. During the peak period of cold load demand, the air-cooled hot and cold water unit is turned on at the same time as the cold source to supplement the user load.

[0022] The design scheme of the present application has the characteristics of high reliability in the form of output in the form of cooling and heat. Under heating conditions: through the coupling of the low-temperature interconnected heat pump outdoor unit and the phase change energy storage technology, an effective heat source is provided for the high-temperature water source heat pump system, realizing stable high-temperature heating hot water supply throughout the heating season (high-temperature water supply of 60°C can be achieved during the peak period of heating load demand, meeting the heating needs of different terminal forms of different energy-saving buildings). Breaking the restrictions on the use of water-source heat pumps, alleviating the problems of low energy efficiency ratio, high compression ratio, severe frosting and high failure rate of air source heat pumps in low ambient temperature operation; under cooling conditions: according to the cooling load demand of the air-conditioning terminal, the water source heat pump is combined with the cooling tower for efficient cooling first, and the low-temperature interconnected heat pump outdoor unit is used for supplementary adjustment when the load is high. It avoids the problems of attenuation of refrigeration capacity and low energy efficiency ratio of air source heat pumps in high-temperature environments, greatly reducing the cost of refrigeration operation.

[0023] The specific embodiments of the present invention are merely explanations of the present invention and are not limitations of the present invention. After reading this specification, those skilled in the art may make modifications to the embodiments without any creative contribution as needed. However, such modifications are protected by the patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for implementing heat supply regulation by an energy storage heat pump coupling system, characterized in that: The energy storage heat pump coupling system comprises an air-cooled hot and cold water unit (1), a water source heat pump unit (3) and a heat storage / cooling device (6). When the system is used as a heating system: the input end of the water source heat pump unit is connected to the output of the air-cooled hot and cold water unit, the input end of the heat storage device is connected to an output of the water source heat pump unit, the other output of the water source heat pump unit is connected to the output of the heat storage device and then connected to a user load system (4); when the system is used as a cooling system: the air-cooled hot and cold water unit, the water source heat pump unit and the heat storage / cooling device are respectively connected to the user load system, and the other output of the water source heat pump unit is connected to the storage device. The input of the hot / cold equipment; the heating regulation process of the system is: the energy storage heat pump coupling system uses electricity as energy to drive the air-cooled hot and cold water units during the low-peak period of electricity consumption. Based on the working principle of the heat pump, the heat transfer medium is raised from the local surface water temperature to the set temperature suitable for the working point of the water source heat pump. As the source side energy supply of the water source heat pump unit, the water source heat pump unit directly supplies part of the output high-temperature heating hot water to the user load through the secondary temperature increase of the heat transfer medium, and transmits the other part to the heat storage equipment for heat storage; during the peak period of electricity consumption, the energy storage device is used as the main heat source to supply heat to the user load. During the peak period of heat load demand in winter: if the external environment is low temperature and high humidity, the air-cooled hot and cold water unit is used to provide input for the water source heat pump unit, and the output of the water source heat pump unit is used as the peak-shaving heat for this period of time together with the energy storage device to supply the user load; if the external environment is low humidity, the water source heat pump unit stops working, and the output of the air-cooled hot and cold water unit is used as the peak-shaving heat for this period of time together with the energy storage device to supply the user load; the high and low humidity standards described here are around 0°C and 70% humidity. The absolute humidity content of the air at this operating point is the high humidity; When the energy storage heat pump coupling system is used to adjust the cooling process, the water source heat pump unit (3) is directly used to store low-temperature medium for the heat storage / cold device during the off-peak period at night. During the cooling process, the water source heat pump unit is first used as the basis to supply the user load. During the peak period of electricity consumption during the day and the peak period of cold load demand, the cold storage device is used as a peak shaving device. During the peak period of cold load demand, the air-cooled hot and cold water unit is simultaneously turned on as a cold source to supplement the user load. During the above adjustment process, the heat storage / cold device is controlled to store and supply heat / cold through feedback based on the load cold and heat demand and the peak and off-peak periods of electricity consumption.

2. The method for implementing heat supply regulation of the energy storage heat pump coupling system according to claim 1, characterized in that: The output end of the heat storage device of the energy storage heat pump coupling system is connected to a valve (5) to realize output control.

3. The method for implementing heat supply regulation of the energy storage heat pump coupling system according to claim 1, characterized in that: The air-cooled hot and cold water units and the water source heat pump units of the energy storage heat pump coupling system are both powered by external power equipment (2).

4. The method for implementing heat supply regulation of the energy storage heat pump coupling system according to claim 1, characterized in that: The user load system is a plurality of parallel systems respectively connected to the mixing pipelines of the heat storage / cooling equipment and the water source heat pump unit.

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