CN207365150U - A kind of family's heat supply network active heat-exchange system in central heating system - Google Patents

Abstract

The utility model discloses an active heat exchange system for a household heating network in a centralized heating system, which includes three cycles, the primary water cycle centralized heating pipe network, the secondary water cycle user heating network and the refrigeration cycle of a jet heat pump, the jet The heat pump uses the hot water in the central heating pipe network for stepwise cooling, and transfers the heat through the refrigeration cycle system and the primary and secondary water cycle systems through the ejector to the radiator at the end of the user. The system of the utility model includes an ejector refrigeration cycle with a heat exchanger. This ejector heat pump technology is simple, inexpensive and reliable, and the mechanism is well understood. It is especially suitable for application in domestic heating networks, and can realize active heat transfer from low-temperature primary return water to secondary high-temperature supply water. The technology of the utility model will significantly reduce the energy consumption of water system transmission and distribution. Energy savings for pumps due to an increased temperature drop of 10‑15°C is estimated at around 50‑60%. Due to the lower heat loss of the central heating network, we can expect greater energy savings.

Description

Active heat exchange system for domestic heating network in a centralized heating system

technical field

The utility model relates to an active enhanced heat exchange system suitable for a household heat network, in particular to an active heat exchange system for a household heat network in a centralized heating system.

Background technique

According to the Ministry of Energy, 30-40% of total energy consumption is used for heating, ventilation and lighting of buildings. The largest proportion of these energy consumptions is the heating demand of buildings. Today, 60% of household heating comes from district heating and combined heat and power plants. Therefore, an efficient central heating system is of great significance in terms of energy saving and greenhouse gas emissions. At present, in today's central heating systems, the annual average supply and return water temperature fluctuations are mostly between 75-100°C and 40-50°C (Frederiksen and Werner, 2013). According to a survey study by Frederiksen and Werner (2013), about 7-10% of the annual cost of district heating systems can be saved by reducing the return water temperature by 10°C. The sharp increase in the heat demand for heating in the city has greatly increased the requirements for the heating area. For this situation, it can be solved by adding another pipe network. It is relatively easy to solve this part of the heat load. However, the sporadic increase in the heat load in the original heating area is out of scale and can only be borne by the nearest secondary heat station, which will lead to insufficient heating of the original heating pipe network. This is because in order to ensure the quality of heating, the water supply temperature of the primary network must be constant. Increasing heat supply can only be achieved by changing the circulating water flow of the primary network and the return water temperature of the primary network. The performance of the secondary station heater determines the return water temperature difference of the primary network, and the heating network pipes have already been laid, especially the main pipe of the primary network, it is difficult to add another network under the given pipe network diameter Circulating water volume. Therefore, to increase the heat supply of the primary network, there are only two ways to re-lay the already laid pipe network and improve the heat transfer performance of the secondary station heat exchanger. The laying of heating pipe network is generally a municipal project, which is not only a huge amount of work but also not a long-term solution to the problem.

Utility model content

In order to solve the deficiencies and existing problems in the prior art, the utility model provides an active heat exchange system for the household heating network in the central heating system, which solves the problem of low effective utilization of heat energy in the central heating system in the prior art, Improve the problem of high cost of heating performance.

The technical scheme of the utility model is as follows: an active heat exchange system for a household heating network in a central heating system, including three cycles, the primary water circulation centralized heating pipe network, the secondary water circulation user heating network and the refrigeration of the jet heat pump Circulation, the ejector heat pump uses the hot water in the central heating pipe network for stepwise cooling, and transfers the heat through the refrigeration cycle system and the primary and secondary water circulation systems through the ejector to the radiator at the end of the user.

The primary water circulation central heating pipe network includes: the water supply of the heating network is first connected to the generator, the outlet of the water path of the generator is connected to the water-water heat exchanger, and the outlet of the water-water heat exchanger is connected to the evaporator The inlet of the waterway, the waterway outlet of the evaporator are connected to the return water end of the heating network; the secondary water circulation user heating network includes: the waterway outlet of the condenser is connected to the water-water heat exchanger, and the water-water heat exchanger is connected to the end radiator of the user, and the waterway of the radiator The outlet is connected to the waterway inlet of the condenser; the refrigeration cycle of the jet heat pump includes: the outlet of the ejector is connected to the inlet of the condenser, and the condenser is divided into two paths, one path enters the generator through the working medium circulation pump, and the outlet of the generator is connected to the ejector to work The other way flows through the throttle valve and enters the evaporator, and the outlet of the evaporator is connected to the injection fluid port of the injector.

Both the primary water circulation central heating pipe network and the secondary water circulation user heating network system are equipped with flow regulating valves.

The beneficial effects of the utility model are: the current heat station technology realizes the heat exchange from the primary city heat network to the local user heat network through the passive heat exchanger. Therefore, the return water temperature of the thermal station depends on the return water temperature of the radiator, while the warm water temperature of the radiator is limited by the air temperature of the heated room space. Due to such limitations, it is difficult for the return water temperature of each thermal station to be lowered below 30°C. The system of the utility model includes an ejector refrigeration cycle with a heat exchanger. This jet heat pump technology is simple, inexpensive and reliable, and the mechanism is well understood. It is especially suitable for application in domestic heating networks, and can realize active heat transfer from low-temperature primary return water to secondary high-temperature supply water. The heat transfer from low-temperature water to high-temperature water is driven by the heat of the central heating network through the jet heat pump, and this driving heat is later transferred to the secondary water cycle for room heating. This technology is suitable for use in domestic heating networks with district heating systems, especially in homes with maximum radiant floor space heating. Its immediate benefit is that it increases the operating temperature drop (Δt) of the district heating network, thus reducing the required water circulation mass flow. This technology will significantly reduce energy consumption in water system distribution. The energy saving of the pump due to the increased temperature drop of 10-15°C is estimated at about 50-60%. Due to the lower heat loss of the central heating network, we can expect greater energy savings. Further energy savings include more heat recovery in the flue gas condenser, etc. The same technique can also be used in district heating stations to reduce return water temperatures in large district heating networks. In addition to energy savings, investments in district heating networks can be reduced due to lower requirements in terms of insulation. Due to the increased heating capacity, the existing central heating network can cover a larger heating area under the condition of large temperature drop Δt, which is another advantage of this technology.

Description of drawings

Fig. 1 is the principle diagram of the active heat exchange system of the household heating network in the central heating system of the present invention;

Among them: 1—generator; 2—water-water heat exchanger; 3—evaporator; 4—ejector; 5—condenser; 6—radiator; 7—working fluid pump; 8—throttle valve; 9— The first flow regulating valve; 10—the second flow regulating valve; 9-1-2-3 is the heating network circulation loop; 2-10-6-5 is the user circulation loop; the rest are jet heat pump working medium circulation loops.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in detail.

Figure 1 shows the principle of the design. Compared to conventional thermal stations with space heating systems with indirectly connected liquid circulation, the design of the new thermal system also has a heat exchanger 2 while adding a jet heat pump. The entire thermal station includes three cycles, the primary water cycle central heating pipe network, the secondary water cycle user heating network and the refrigeration cycle of the jet heat pump. The hot water from the primary heating pipe network first conducts heat exchange with the generator 1 of the jet heat pump. After the heat exchange in the generator, the temperature of the primary hot water will drop by 20-30°C. Then the primary hot water conducts further heat exchange in the heat exchanger 2 with the secondary water circulation used to heat the radiator at the user end, and the temperature drop of the water is further reduced by 20-30°C. Finally, the primary hot water is heat-exchanged in the evaporator 3 of the jet heat pump, and further cooled by 15-20°C. After being cooled by generator 1, heat exchanger 2, and evaporator 3, the return water temperature of the primary hot water back to the central heating pipe network will be reduced to 15-20°C, which will be lower than that of the return water of the traditional heat station. The minimum temperature is 10-15°C lower. The secondary water circulation of the user's heating network obtains heat through the condenser 5 and the heat exchanger 2 of the jet heat pump. The heat gained from the condenser is the sum of the heat gained from the generator 1 and the evaporator 3 . Thus, all heat release from the primary water supply of the district heating network will be transferred to the domestic users without heat loss. However, the Δt of the heat supply network of the secondary heat station increased by 10-15°C.

Although the utility model has been described above in conjunction with the accompanying drawings, the utility model is not limited to the above-mentioned specific functions and work processes, and the above-mentioned specific implementation is only illustrative and not restrictive. Under the enlightenment of the utility model, personnel can also make many forms without departing from the purpose of the utility model and the scope protected by the claims, and these all belong to the protection scope of the utility model.

Claims (3)

1. An active heat exchange system for a household heating network in a central heating system, characterized in that it comprises three cycles, the primary water circulation central heating pipe network, the secondary water circulation user heating network and the refrigeration cycle of the jet heat pump, The ejector heat pump uses the hot water in the central heating pipe network for stepwise cooling, and transfers the heat through the ejector to the radiator at the end of the user through the refrigeration cycle system and the primary and secondary water cycle systems. 2. According to the active heat exchange system of the household heating network in the central heating system of claim 1, it is characterized in that, through pipelines connecting each device in the system, the primary water circulation central heating pipe network comprises: a heating network The water supply is first connected to the generator, the outlet of the water path of the generator is connected to the water-water heat exchanger, the outlet of the water-water heat exchanger is connected to the water path inlet of the evaporator, and the water path outlet of the evaporator is connected to the return water end of the heating network; the secondary water circulation user heating network includes The outlet of the condenser waterway is connected to the water-water heat exchanger, and the water-water heat exchanger is connected to the end radiator of the user, and the waterway outlet of the radiator is connected to the waterway inlet of the condenser; the refrigeration cycle of the jet heat pump includes: the outlet of the ejector is connected to the condenser The inlet and the condenser are divided into two paths, one path enters the generator through the working fluid circulation pump, the outlet end of the generator is connected to the working fluid port of the ejector, the other path flows through the throttle valve and enters the evaporator, and the outlet end of the evaporator is connected to the ejector injection fluid port. 3. According to the active heat exchange system of the household heating network in the central heating system of claim 1, it is characterized in that the primary water circulation central heating pipe network and the secondary water circulation user heating network system are equipped with flow regulating valves .